chore: checkpoint before Python removal

vendor/h2/.cargo_vcs_info.json

@@ -0,0 +1,6 @@
+{
+  "git": {
+    "sha1": "2aeb81fdb5f1d96ee035266186f94fa2927616c7"
+  },
+  "path_in_vcs": ""
+}

vendor/h2/.github/FUNDING.yml

@@ -0,0 +1 @@
+github: seanmonstar

vendor/h2/.github/workflows/CI.yml

@@ -0,0 +1,115 @@
+name: CI
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+env:
+  RUST_BACKTRACE: 1
+
+jobs:
+  style:
+    name: Check Style
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+
+      - run: cargo fmt --all --check
+
+  test:
+    name: Test
+    needs: [style]
+    runs-on: ubuntu-latest
+    env:
+      RUSTFLAGS: -Dwarnings
+    strategy:
+      matrix:
+        rust:
+          - nightly
+          - beta
+          - stable
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Rust (${{ matrix.rust }})
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+
+      - name: Install libssl-dev
+        run: sudo apt-get update && sudo apt-get install libssl-dev
+      - name: Build without unstable flag
+        run: cargo build
+
+      - name: Check with unstable flag
+        run: cargo check --features unstable
+
+      - name: Run lib tests and doc tests
+        run: cargo test
+
+      - name: Run integration tests
+        run: cargo test -p h2-tests
+
+      - name: Run h2spec
+        run: ./ci/h2spec.sh
+        if: matrix.rust == 'stable'
+
+  #clippy_check:
+  #  runs-on: ubuntu-latest
+  #  steps:
+  #    - uses: actions/checkout@v4
+  #    - name: Run Clippy
+  #      run: cargo clippy --all-targets --all-features
+
+  msrv:
+    name: Check MSRV
+    needs: [style]
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Get MSRV from package metadata
+        id: msrv
+        run: grep rust-version Cargo.toml | cut -d '"' -f2 | sed 's/^/version=/' >> $GITHUB_OUTPUT
+
+      - name: Install Rust (${{ steps.metadata.outputs.msrv }})
+        id: msrv-toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ steps.msrv.outputs.version }}
+
+      - name: Pin some dependencies for MSRV
+        run: |
+          cargo update --package tokio-util --precise 0.7.11
+          cargo update --package tokio --precise 1.38.1
+          cargo update --package indexmap --precise 2.11.3
+          cargo update --package hashbrown --precise 0.15.0
+          cargo update --package once_cell --precise 1.20.3
+          cargo update --package tracing --precise 0.1.41
+          cargo update --package tracing-subscriber --precise 0.3.19
+          cargo update --package tracing-core --precise 0.1.33
+          cargo update --package itoa --precise 1.0.15
+
+
+      - run: cargo check -p h2
+
+  minimal-versions:
+    runs-on: ubuntu-latest
+    needs: [style]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@nightly
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: taiki-e/install-action@cargo-hack
+      - uses: taiki-e/install-action@cargo-minimal-versions
+      - run: cargo minimal-versions --ignore-private check

vendor/h2/CHANGELOG.md

@@ -0,0 +1,388 @@
+# 0.4.13 (January 5, 2026)
+
+* Add support for 1xx informational responses on client and server side.
+* Fix auto-releasing of padding bytes of DATA frames for flow control windows.
+* Fix to stop assigning capacity to pending streams which can't use it yet.
+* Fix tracing to not grab the parent for the connection span.
+
+# 0.4.12 (August 5, 2025)
+
+* Fix default limits on max stored reset streams and duration to more reasonable values.
+
+# 0.4.11 (June 30, 2025)
+
+* Fix client to not return an error when a clean shutdown otherwise doesn't get a TLS close_notify, which some servers don't bother sending.
+
+# 0.4.10 (May 5, 2025)
+
+* Fix `is_end_stream()` to return true only when ended cleanly, not when errored.
+
+# 0.4.9 (April 14, 2025)
+
+* Add `sever::Connection::has_streams()` method to check for active streams.
+
+# 0.4.8 (February 18, 2025)
+
+* Fix handling implicit stream resets at the more correct time.
+* Fix window size decrements of send-closed streams.
+* Fix reclaiming of reserved capacity when streams are closed.
+* Fix to no longer call `poll_flush` after `poll_shutdown`.
+* Fix busy loop in task when poll_shutdown returns pending.
+
+# 0.4.7 (November 19, 2024)
+
+* Fix treating HEADERS frames with a non-zero content-length but END_STREAM flag as malformed.
+* Fix notifying the stream task when automatically reset on receipt of a stream error.
+
+# 0.4.6 (August 19, 2024)
+
+* Add `current_max_send_streams()` and `current_max_recv_streams()` to `client::SendRequest`.
+* Fix sending a PROTOCOL_ERROR instead of REFUSED_STREAM when receiving oversized headers.
+* Fix notifying a PushPromise task properly.
+* Fix notifying a stream task when reset.
+
+# 0.4.5 (May 17, 2024)
+
+* Fix race condition that sometimes hung connections during shutdown.
+* Fix pseudo header construction for CONNECT and OPTIONS requests.
+
+# 0.4.4 (April 3, 2024)
+
+* Limit number of CONTINUATION frames for misbehaving connections.
+
+# 0.4.3 (March 15, 2024)
+
+* Fix flow control limits to not apply until receiving SETTINGS ack.
+* Fix not returning an error if IO ended without `close_notify`.
+* Improve performance of decoding many headers.
+
+# 0.4.2 (January 17th, 2024)
+
+* Limit error resets for misbehaving connections.
+* Fix selecting MAX_CONCURRENT_STREAMS value if no value is advertised initially.
+
+# 0.4.1 (January 8, 2024)
+
+* Fix assigning connection capacity which could starve streams in some instances.
+
+# 0.4.0 (November 15, 2023)
+
+* Update to `http` 1.0.
+* Remove deprecated `Server::poll_close()`.
+
+# 0.3.22 (November 15, 2023)
+
+* Add `header_table_size(usize)` option to client and server builders.
+* Improve throughput when vectored IO is not available.
+* Update indexmap to 2.
+
+# 0.3.21 (August 21, 2023)
+
+* Fix opening of new streams over peer's max concurrent limit.
+* Fix `RecvStream` to return data even if it has received a `CANCEL` stream error.
+* Update MSRV to 1.63.
+
+# 0.3.20 (June 26, 2023)
+
+* Fix panic if a server received a request with a `:status` pseudo header in the 1xx range.
+* Fix panic if a reset stream had pending push promises that were more than allowed.
+* Fix potential flow control overflow by subtraction, instead returning a connection error.
+
+# 0.3.19 (May 12, 2023)
+
+* Fix counting reset streams when triggered by a GOAWAY.
+* Send `too_many_resets` in opaque debug data of GOAWAY when too many resets received.
+
+# 0.3.18 (April 17, 2023)
+
+* Fix panic because of opposite check in `is_remote_local()`.
+
+# 0.3.17 (April 13, 2023)
+
+* Add `Error::is_library()` method to check if the originated inside `h2`.
+* Add `max_pending_accept_reset_streams(usize)` option to client and server
+  builders.
+* Fix theoretical memory growth when receiving too many HEADERS and then
+  RST_STREAM frames faster than an application can accept them off the queue.
+  (CVE-2023-26964)
+
+# 0.3.16 (February 27, 2023)
+
+* Set `Protocol` extension on requests when received Extended CONNECT requests.
+* Remove `B: Unpin + 'static` bound requiremented of bufs
+* Fix releasing of frames when stream is finished, reducing memory usage.
+* Fix panic when trying to send data and connection window is available, but stream window is not.
+* Fix spurious wakeups when stream capacity is not available.
+
+# 0.3.15 (October 21, 2022)
+
+* Remove `B: Buf` bound on `SendStream`'s parameter
+* add accessor for `StreamId` u32
+
+# 0.3.14 (August 16, 2022)
+
+* Add `Error::is_reset` function.
+* Bump MSRV to Rust 1.56.
+* Return `RST_STREAM(NO_ERROR)` when the server early responds.
+
+# 0.3.13 (March 31, 2022)
+
+* Update private internal `tokio-util` dependency.
+
+# 0.3.12 (March 9, 2022)
+
+* Avoid time operations that can panic (#599)
+* Bump MSRV to Rust 1.49 (#606)
+* Fix header decoding error when a header name is contained at a continuation
+  header boundary (#589)
+* Remove I/O type names from handshake `tracing` spans (#608)
+
+# 0.3.11 (January 26, 2022)
+
+* Make `SendStream::poll_capacity` never return `Ok(Some(0))` (#596)
+* Fix panic when receiving already reset push promise (#597)
+
+# 0.3.10 (January 6, 2022)
+
+* Add `Error::is_go_away()` and `Error::is_remote()` methods.
+* Fix panic if receiving malformed PUSH_PROMISE with stream ID of 0.
+
+# 0.3.9 (December 9, 2021)
+
+* Fix hang related to new `max_send_buffer_size`.
+
+# 0.3.8 (December 8, 2021)
+
+* Add "extended CONNECT support". Adds `h2::ext::Protocol`, which is used for request and response extensions to connect new protocols over an HTTP/2 stream.
+* Add `max_send_buffer_size` options to client and server builders, and a default of ~400MB. This acts like a high-water mark for the `poll_capacity()` method.
+* Fix panic if receiving malformed HEADERS with stream ID of 0.
+
+# 0.3.7 (October 22, 2021)
+
+* Fix panic if server sends a malformed frame on a stream client was about to open.
+* Fix server to treat `:status` in a request as a stream error instead of connection error.
+
+# 0.3.6 (September 30, 2021)
+
+* Fix regression of `h2::Error` that were created via `From<h2::Reason>` not returning their reason code in `Error::reason()`.
+
+# 0.3.5 (September 29, 2021)
+
+* Fix sending of very large headers. Previously when a single header was too big to fit in a single `HEADERS` frame, an error was returned. Now it is broken up and sent correctly.
+* Fix buffered data field to be a bigger integer size.
+* Refactor error format to include what initiated the error (remote, local, or user), if it was a stream or connection-level error, and any received debug data.
+
+# 0.3.4 (August 20, 2021)
+
+* Fix panic when encoding header size update over a certain size.
+* Fix `SendRequest` to wake up connection when dropped.
+* Fix potential hang if `RecvStream` is placed in the request or response `extensions`.
+* Stop calling `Instant::now` if zero reset streams are configured.
+
+# 0.3.3 (April 29, 2021)
+
+* Fix client being able to make `CONNECT` requests without a `:path`.
+* Expose `RecvStream::poll_data`.
+* Fix some docs.
+
+# 0.3.2 (March 24, 2021)
+
+* Fix incorrect handling of received 1xx responses on the client when the request body is still streaming.
+
+# 0.3.1 (February 26, 2021)
+
+* Add `Connection::max_concurrent_recv_streams()` getter.
+* Add `Connection::max_concurrent_send_streams()` getter.
+* Fix client to ignore receipt of 1xx headers frames.
+* Fix incorrect calculation of pseudo header lengths when determining if a received header is too big.
+* Reduce monomorphized code size of internal code.
+
+# 0.3.0 (December 23, 2020)
+
+* Update to Tokio v1 and Bytes v1.
+* Disable `tracing`'s `log` feature. (It can still be enabled by a user in their own `Cargo.toml`.)
+
+# 0.2.7 (October 22, 2020)
+
+* Fix stream ref count when sending a push promise
+* Fix receiving empty DATA frames in response to a HEAD request
+* Fix handling of client disabling SERVER_PUSH
+
+# 0.2.6 (July 13, 2020)
+
+* Integrate `tracing` directly where `log` was used. (For 0.2.x, `log`s are still emitted by default.)
+
+# 0.2.5 (May 6, 2020)
+
+* Fix rare debug assert failure in store shutdown.
+
+# 0.2.4 (March 30, 2020)
+
+* Fix when receiving `SETTINGS_HEADER_TABLE_SIZE` setting.
+
+# 0.2.3 (March 25, 2020)
+
+* Fix server being able to accept `CONNECT` requests without `:scheme` or `:path`.
+* Fix receiving a GOAWAY frame from updating the recv max ID, it should only update max send ID.
+
+# 0.2.2 (March 3, 2020)
+
+* Reduce size of `FlowControl` and `RecvStream`.
+
+# 0.2.1 (December 6, 2019)
+
+* Relax `Unpin` bounds on the send `Buf` generic.
+
+# 0.2.0 (December 3, 2019)
+
+* Add `server::Connection::set_initial_window_size` and `client::Connection::set_initial_window_size` which can adjust the `INITIAL_WINDOW_SIZE` setting on an existing connection (#421).
+* Update to `http` v0.2.
+* Update to `tokio` v0.2.
+* Change `unstable-stream` feature to `stream`.
+* Change `ReserveCapacity` to `FlowControl` (#423).
+* Remove `From<io::Error>` for `Error`.
+
+# 0.2.0-alpha.3 (October 1, 2019)
+
+* Update to futures `0.3.0-alpha.19`.
+* Update to tokio `0.2.0-alpha.6`.
+
+# 0.2.0-alpha.2 (September 20, 2019)
+
+* Add server support for `PUSH_PROMISE`s (#327).
+* Update to tokio `0.2.0-alpha.5`.
+* Change `stream` feature to `unstable-stream`.
+
+# 0.2.0-alpha.1 (August 30, 2019)
+
+* Update from `futures` 0.1 to `std::future::Future`.
+* Update `AsyncRead`/`AsyncWrite` to `tokio-io` 0.2 alpha.
+* Change `Stream` implementations to be optional, default disabled. Specific async and poll functions are now inherent, and `Stream` can be re-enabled with the `stream` cargo feature.
+
+# 0.1.25 (June 28, 2019)
+
+* Fix to send a `RST_STREAM` instead of `GOAWAY` if receiving a frame on a previously closed stream.
+* Fix receiving trailers without an end-stream flag to be a stream error instead of connection error.
+
+# 0.1.24 (June 17, 2019)
+
+* Fix server wrongly rejecting requests that don't have an `:authority` header (#372).
+
+# 0.1.23 (June 4, 2019)
+
+* Fix leaking of received DATA frames if the `RecvStream` is never polled (#368).
+
+# 0.1.22 (June 3, 2019)
+
+* Fix rare panic when remote sends `RST_STREAM` or `GOAWAY` for a stream pending window capacity (#364).
+
+# 0.1.21 (May 30, 2019)
+
+* Fix write loop when a header didn't fit in write buffer.
+
+# 0.1.20 (May 16, 2019)
+
+* Fix lifetime conflict for older compilers.
+
+# 0.1.19 (May 15, 2019)
+
+* Fix rare crash if `CONTINUATION` frame resumed in the middle of headers with the same name.
+* Fix HPACK encoder using an old evicted index for repeated header names.
+
+# 0.1.18 (April 9, 2019)
+
+* Fix `server::Connection::abrupt_shutdown` to no longer return the same error the user sent (#352).
+
+# 0.1.17 (March 12, 2019)
+
+* Add user PING support (#346).
+* Fix notifying a `RecvStream` task if locally sending a reset.
+* Fix connections "hanging" when all handles are dropped but some streams had been reset.
+
+# 0.1.16 (January 24, 2019)
+
+* Log header values when malformed (#342).
+
+# 0.1.15 (January 12, 2019)
+
+* Fix race condition bug related to shutting down the client (#338).
+
+# 0.1.14 (December 5, 2018)
+
+* Fix closed streams to always return window capacity to the connection (#334).
+* Fix locking when `Debug` printing an `OpaqueStreamRef` (#333).
+* Fix inverted split for DATA frame padding (#330).
+* Reduce `Debug` noise for `Frame` (#329).
+
+# 0.1.13 (October 16, 2018)
+
+* Add client support for Push Promises (#314).
+* Expose `io::Error` from `h2::Error` (#311)
+* Misc bug fixes (#304, #309, #319, #313, #320).
+
+# 0.1.12 (August 8, 2018)
+
+* Fix initial send window size (#301).
+* Fix panic when calling `reserve_capacity` after connection has been closed (#302).
+* Fix handling of incoming `SETTINGS_INITIAL_WINDOW_SIZE`. (#299)
+
+# 0.1.11 (July 31, 2018)
+
+* Add `stream_id` accessors to public API types (#292).
+* Fix potential panic when dropping clients (#295).
+* Fix busy loop when shutting down server (#296).
+
+# 0.1.10 (June 15, 2018)
+
+* Fix potential panic in `SendRequest::poll_ready()` (#281).
+* Fix infinite loop on reset connection during prefix (#285).
+
+# 0.1.9 (May 31, 2018)
+
+* Add `poll_reset` to `SendResponse` and `SendStream` (#279).
+
+# 0.1.8 (May 23, 2018)
+
+* Fix client bug when max streams is reached. (#277)
+
+# 0.1.7 (May 14, 2018)
+
+* Misc bug fixes (#266, #273, #261, #275).
+
+# 0.1.6 (April 24, 2018)
+
+* Misc bug fixes related to stream management (#258, #260, #262).
+
+# 0.1.5 (April 6, 2018)
+
+* Fix the `last_stream_id` sent during graceful GOAWAY (#254).
+
+# 0.1.4 (April 5, 2018)
+
+* Add `initial_connection_window_size` to client and server `Builder`s (#249).
+* Add `graceful_shutdown` and `abrupt_shutdown` to `server::Connection`,
+  deprecating `close_connection` (#250).
+
+# 0.1.3 (March 28, 2018)
+
+* Allow configuring max streams before the peer's settings frame is
+  received (#242).
+* Fix HPACK decoding bug with regards to large literals (#244).
+* Fix state transition bug triggered by receiving a RST_STREAM frame (#247).
+
+# 0.1.2 (March 13, 2018)
+
+* Fix another bug relating to resetting connections and reaching
+  max concurrency (#238).
+
+# 0.1.1 (March 8, 2018)
+
+* When streams are dropped, close the connection (#222).
+* Notify send tasks on connection error (#231).
+* Fix bug relating to resetting connections and reaching max concurrency (#235).
+* Normalize HTTP request path to satisfy HTTP/2.0 specification (#228).
+* Update internal dependencies.
+
+# 0.1.0 (Jan 12, 2018)
+
+* Initial release

vendor/h2/CONTRIBUTING.md

@@ -0,0 +1,84 @@
+# Contributing to _h2_ #
+
+:balloon: Thanks for your help improving the project!
+
+## Getting Help ##
+
+If you have a question about the h2 library or have encountered problems using it, you may
+[file an issue][issue] or ask a question on the [Tokio Discord][discord].
+
+## Submitting a Pull Request ##
+
+Do you have an improvement?
+
+1. Submit an [issue][issue] describing your proposed change.
+2. We will try to respond to your issue promptly.
+3. Fork this repo, develop and test your code changes. See the project's [README](README.md) for further information about working in this repository.
+4. Submit a pull request against this repo's `master` branch.
+5. Your branch may be merged once all configured checks pass, including:
+    - Code review has been completed.
+    - The branch has passed tests in CI.
+
+## Committing ##
+
+When initially submitting a pull request, we prefer a single squashed commit. It
+is preferable to split up contributions into multiple pull requests if the
+changes are unrelated. All pull requests are squashed when merged, but
+squashing yourself gives you better control over the commit message.
+
+After the pull request is submitted, all changes should be done in separate
+commits. This makes reviewing the evolution of the pull request easier. We will
+squash all the changes into a single commit when we merge the pull request.
+
+### Commit messages ###
+
+Finalized commit messages should be in the following format:
+
+```
+Subject
+
+Problem
+
+Solution
+
+Validation
+```
+
+#### Subject ####
+
+- one line, <= 50 characters
+- describe what is done; not the result
+- use the active voice
+- capitalize first word and proper nouns
+- do not end in a period — this is a title/subject
+- reference the github issue by number
+
+##### Examples #####
+
+```
+bad: server disconnects should cause dst client disconnects.
+good: Propagate disconnects from source to destination
+```
+
+```
+bad: support tls servers
+good: Introduce support for server-side TLS (#347)
+```
+
+#### Problem ####
+
+Explain the context and why you're making that change.  What is the problem
+you're trying to solve? In some cases there is not a problem and this can be
+thought of as being the motivation for your change.
+
+#### Solution ####
+
+Describe the modifications you've made.
+
+#### Validation ####
+
+Describe the testing you've done to validate your change.  Performance-related
+changes should include before- and after- benchmark results.
+
+[issue]: https://github.com/hyperium/h2/issues/new
+[discord]: https://discord.gg/tokio

vendor/h2/Cargo.lock

@@ -0,0 +1,788 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "atomic-waker"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1505bd5d3d116872e7271a6d4e16d81d0c8570876c8de68093a09ac269d8aac0"
+
+[[package]]
+name = "aws-lc-rs"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b5ce75405893cd713f9ab8e297d8e438f624dde7d706108285f7e17a25a180f"
+dependencies = [
+ "aws-lc-sys",
+ "zeroize",
+]
+
+[[package]]
+name = "aws-lc-sys"
+version = "0.34.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "179c3777a8b5e70e90ea426114ffc565b2c1a9f82f6c4a0c5a34aa6ef5e781b6"
+dependencies = [
+ "cc",
+ "cmake",
+ "dunce",
+ "fs_extra",
+]
+
+[[package]]
+name = "bytes"
+version = "1.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b35204fbdc0b3f4446b89fc1ac2cf84a8a68971995d0bf2e925ec7cd960f9cb3"
+
+[[package]]
+name = "cc"
+version = "1.2.48"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c481bdbf0ed3b892f6f806287d72acd515b352a4ec27a208489b8c1bc839633a"
+dependencies = [
+ "find-msvc-tools",
+ "jobserver",
+ "libc",
+ "shlex",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "cmake"
+version = "0.1.54"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7caa3f9de89ddbe2c607f4101924c5abec803763ae9534e4f4d7d8f84aa81f0"
+dependencies = [
+ "cc",
+]
+
+[[package]]
+name = "dunce"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "92773504d58c093f6de2459af4af33faa518c13451eb8f2b5698ed3d36e7c813"
+
+[[package]]
+name = "env_logger"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4cd405aab171cb85d6735e5c8d9db038c17d3ca007a4d2c25f337935c3d90580"
+dependencies = [
+ "log",
+]
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a3076410a55c90011c298b04d0cfa770b00fa04e1e3c97d3f6c9de105a03844"
+
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
+[[package]]
+name = "fs_extra"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42703706b716c37f96a77aea830392ad231f44c9e9a67872fa5548707e11b11c"
+
+[[package]]
+name = "futures-core"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05f29059c0c2090612e8d742178b0580d2dc940c837851ad723096f87af6663e"
+
+[[package]]
+name = "futures-sink"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e575fab7d1e0dcb8d0c7bcf9a63ee213816ab51902e6d244a95819acacf1d4f7"
+
+[[package]]
+name = "getrandom"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "r-efi",
+ "wasip2",
+]
+
+[[package]]
+name = "h2"
+version = "0.4.13"
+dependencies = [
+ "atomic-waker",
+ "bytes",
+ "env_logger",
+ "fnv",
+ "futures-core",
+ "futures-sink",
+ "hex",
+ "http",
+ "indexmap",
+ "quickcheck",
+ "rand",
+ "serde",
+ "serde_json",
+ "slab",
+ "tokio",
+ "tokio-rustls",
+ "tokio-util",
+ "tracing",
+ "walkdir",
+ "webpki-roots",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
+[[package]]
+name = "http"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3ba2a386d7f85a81f119ad7498ebe444d2e22c2af0b86b069416ace48b3311a"
+dependencies = [
+ "bytes",
+ "itoa",
+]
+
+[[package]]
+name = "indexmap"
+version = "2.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ad4bb2b565bca0645f4d68c5c9af97fba094e9791da685bf83cb5f3ce74acf2"
+dependencies = [
+ "equivalent",
+ "hashbrown",
+]
+
+[[package]]
+name = "itoa"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
+
+[[package]]
+name = "jobserver"
+version = "0.1.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9afb3de4395d6b3e67a780b6de64b51c978ecf11cb9a462c66be7d4ca9039d33"
+dependencies = [
+ "getrandom 0.3.4",
+ "libc",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.178"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37c93d8daa9d8a012fd8ab92f088405fb202ea0b6ab73ee2482ae66af4f42091"
+
+[[package]]
+name = "log"
+version = "0.4.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
+
+[[package]]
+name = "memchr"
+version = "2.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+
+[[package]]
+name = "mio"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a69bcab0ad47271a0234d9422b131806bf3968021e5dc9328caf2d4cd58557fc"
+dependencies = [
+ "libc",
+ "wasi",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.21.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b3cff922bd51709b605d9ead9aa71031d81447142d828eb4a6eba76fe619f9b"
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quickcheck"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "588f6378e4dd99458b60ec275b4477add41ce4fa9f64dcba6f15adccb19b50d6"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.42"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a338cc41d27e6cc6dce6cefc13a0729dfbb81c262b1f519331575dd80ef3067f"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "r-efi"
+version = "5.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom 0.2.16",
+]
+
+[[package]]
+name = "ring"
+version = "0.17.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4689e6c2294d81e88dc6261c768b63bc4fcdb852be6d1352498b114f61383b7"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "getrandom 0.2.16",
+ "libc",
+ "untrusted",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "rustls"
+version = "0.23.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "533f54bc6a7d4f647e46ad909549eda97bf5afc1585190ef692b4286b198bd8f"
+dependencies = [
+ "aws-lc-rs",
+ "log",
+ "once_cell",
+ "rustls-pki-types",
+ "rustls-webpki",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-pki-types"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "708c0f9d5f54ba0272468c1d306a52c495b31fa155e91bc25371e6df7996908c"
+dependencies = [
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-webpki"
+version = "0.103.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2ffdfa2f5286e2247234e03f680868ac2815974dc39e00ea15adc445d0aafe52"
+dependencies = [
+ "aws-lc-rs",
+ "ring",
+ "rustls-pki-types",
+ "untrusted",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.145"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "402a6f66d8c709116cf22f558eab210f5a50187f702eb4d7e5ef38d9a7f1c79c"
+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+ "serde_core",
+]
+
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "slab"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a2ae44ef20feb57a68b23d846850f861394c2e02dc425a50098ae8c90267589"
+
+[[package]]
+name = "socket2"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17129e116933cf371d018bb80ae557e889637989d8638274fb25622827b03881"
+dependencies = [
+ "libc",
+ "windows-sys 0.60.2",
+]
+
+[[package]]
+name = "subtle"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+
+[[package]]
+name = "syn"
+version = "2.0.111"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "tokio"
+version = "1.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff360e02eab121e0bc37a2d3b4d4dc622e6eda3a8e5253d5435ecf5bd4c68408"
+dependencies = [
+ "bytes",
+ "libc",
+ "mio",
+ "pin-project-lite",
+ "socket2",
+ "tokio-macros",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "tokio-rustls"
+version = "0.26.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1729aa945f29d91ba541258c8df89027d5792d85a8841fb65e8bf0f4ede4ef61"
+dependencies = [
+ "rustls",
+ "tokio",
+]
+
+[[package]]
+name = "tokio-util"
+version = "0.7.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2efa149fe76073d6e8fd97ef4f4eca7b67f599660115591483572e406e165594"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "tracing"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d15d90a0b5c19378952d479dc858407149d7bb45a14de0142f6c534b16fc647"
+dependencies = [
+ "pin-project-lite",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a04e24fab5c89c6a36eb8558c9656f30d81de51dfa4d3b45f26b21d61fa0a6c"
+dependencies = [
+ "once_cell",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
+
+[[package]]
+name = "untrusted"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
+
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
+[[package]]
+name = "wasip2"
+version = "1.0.1+wasi-0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0562428422c63773dad2c345a1882263bbf4d65cf3f42e90921f787ef5ad58e7"
+dependencies = [
+ "wit-bindgen",
+]
+
+[[package]]
+name = "webpki-roots"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2878ef029c47c6e8cf779119f20fcf52bde7ad42a731b2a304bc221df17571e"
+dependencies = [
+ "rustls-pki-types",
+]
+
+[[package]]
+name = "winapi-util"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "windows-link"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+dependencies = [
+ "windows-targets 0.53.5",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm 0.52.6",
+ "windows_aarch64_msvc 0.52.6",
+ "windows_i686_gnu 0.52.6",
+ "windows_i686_gnullvm 0.52.6",
+ "windows_i686_msvc 0.52.6",
+ "windows_x86_64_gnu 0.52.6",
+ "windows_x86_64_gnullvm 0.52.6",
+ "windows_x86_64_msvc 0.52.6",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.53.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
+dependencies = [
+ "windows-link",
+ "windows_aarch64_gnullvm 0.53.1",
+ "windows_aarch64_msvc 0.53.1",
+ "windows_i686_gnu 0.53.1",
+ "windows_i686_gnullvm 0.53.1",
+ "windows_i686_msvc 0.53.1",
+ "windows_x86_64_gnu 0.53.1",
+ "windows_x86_64_gnullvm 0.53.1",
+ "windows_x86_64_msvc 0.53.1",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
+
+[[package]]
+name = "wit-bindgen"
+version = "0.46.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
+
+[[package]]
+name = "zerocopy"
+version = "0.8.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd74ec98b9250adb3ca554bdde269adf631549f51d8a8f8f0a10b50f1cb298c3"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8a8d209fdf45cf5138cbb5a506f6b52522a25afccc534d1475dad8e31105c6a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "zeroize"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"

vendor/h2/Cargo.toml

@@ -0,0 +1,159 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+rust-version = "1.63"
+name = "h2"
+version = "0.4.13"
+authors = [
+    "Carl Lerche <me@carllerche.com>",
+    "Sean McArthur <sean@seanmonstar.com>",
+]
+build = false
+exclude = [
+    "fixtures/**",
+    "ci/**",
+]
+autolib = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = "An HTTP/2 client and server"
+documentation = "https://docs.rs/h2"
+readme = "README.md"
+keywords = [
+    "http",
+    "async",
+    "non-blocking",
+]
+categories = [
+    "asynchronous",
+    "web-programming",
+    "network-programming",
+]
+license = "MIT"
+repository = "https://github.com/hyperium/h2"
+
+[package.metadata.docs.rs]
+features = ["stream"]
+
+[features]
+stream = []
+unstable = []
+
+[lib]
+name = "h2"
+path = "src/lib.rs"
+
+[[example]]
+name = "akamai"
+path = "examples/akamai.rs"
+
+[[example]]
+name = "client"
+path = "examples/client.rs"
+
+[[example]]
+name = "server"
+path = "examples/server.rs"
+
+[[bench]]
+name = "main"
+path = "benches/main.rs"
+harness = false
+
+[dependencies.atomic-waker]
+version = "1.0.0"
+
+[dependencies.bytes]
+version = "1"
+
+[dependencies.fnv]
+version = "1.0.5"
+
+[dependencies.futures-core]
+version = "0.3"
+default-features = false
+
+[dependencies.futures-sink]
+version = "0.3"
+default-features = false
+
+[dependencies.http]
+version = "1"
+
+[dependencies.indexmap]
+version = "2"
+features = ["std"]
+
+[dependencies.slab]
+version = "0.4.2"
+
+[dependencies.tokio]
+version = "1"
+features = ["io-util"]
+
+[dependencies.tokio-util]
+version = "0.7.1"
+features = [
+    "codec",
+    "io",
+]
+
+[dependencies.tracing]
+version = "0.1.35"
+features = ["std"]
+default-features = false
+
+[dev-dependencies.env_logger]
+version = "0.10"
+default-features = false
+
+[dev-dependencies.hex]
+version = "0.4.3"
+
+[dev-dependencies.quickcheck]
+version = "1.0.3"
+default-features = false
+
+[dev-dependencies.rand]
+version = "0.8.4"
+
+[dev-dependencies.serde]
+version = "1.0.0"
+
+[dev-dependencies.serde_json]
+version = "1.0.0"
+
+[dev-dependencies.tokio]
+version = "1"
+features = [
+    "rt-multi-thread",
+    "macros",
+    "sync",
+    "net",
+]
+
+[dev-dependencies.tokio-rustls]
+version = "0.26"
+
+[dev-dependencies.walkdir]
+version = "2.3.2"
+
+[dev-dependencies.webpki-roots]
+version = "1"
+
+[lints.rust.unexpected_cfgs]
+level = "warn"
+priority = 0
+check-cfg = ["cfg(fuzzing)"]

vendor/h2/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) 2017 h2 authors
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

vendor/h2/README.md

@@ -0,0 +1,58 @@
+# H2
+
+A Tokio aware, HTTP/2 client & server implementation for Rust.
+
+[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
+[![Crates.io](https://img.shields.io/crates/v/h2.svg)](https://crates.io/crates/h2)
+[![Documentation](https://docs.rs/h2/badge.svg)][dox]
+
+More information about this crate can be found in the [crate documentation][dox].
+
+[dox]: https://docs.rs/h2
+
+## Features
+
+* Client and server HTTP/2 implementation.
+* Implements the full HTTP/2 specification.
+* Passes [h2spec](https://github.com/summerwind/h2spec).
+* Focus on performance and correctness.
+* Built on [Tokio](https://tokio.rs).
+
+## Non goals
+
+This crate is intended to only be an implementation of the HTTP/2
+specification. It does not handle:
+
+* Managing TCP connections
+* HTTP 1.0 upgrade
+* TLS
+* Any feature not described by the HTTP/2 specification.
+
+This crate is now used by [hyper](https://github.com/hyperium/hyper), which will provide all of these features.
+
+## Usage
+
+To use `h2`, first add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+h2 = "0.4"
+```
+
+Next, add this to your crate:
+
+```rust
+extern crate h2;
+
+use h2::server::Connection;
+
+fn main() {
+    // ...
+}
+```
+
+## FAQ
+
+**Is this an embedded Java SQL database engine?**
+
+[No](https://www.h2database.com).

vendor/h2/benches/main.rs

@@ -0,0 +1,148 @@
+use bytes::Bytes;
+use h2::{
+    client,
+    server::{self, SendResponse},
+    RecvStream,
+};
+use http::Request;
+
+use std::{
+    error::Error,
+    time::{Duration, Instant},
+};
+
+use tokio::net::{TcpListener, TcpStream};
+
+const NUM_REQUESTS_TO_SEND: usize = 100_000;
+
+// The actual server.
+async fn server(addr: &str) -> Result<(), Box<dyn Error + Send + Sync>> {
+    let listener = TcpListener::bind(addr).await?;
+
+    loop {
+        if let Ok((socket, _peer_addr)) = listener.accept().await {
+            tokio::spawn(async move {
+                if let Err(e) = serve(socket).await {
+                    println!("  -> err={:?}", e);
+                }
+            });
+        }
+    }
+}
+
+async fn serve(socket: TcpStream) -> Result<(), Box<dyn Error + Send + Sync>> {
+    let mut connection = server::handshake(socket).await?;
+    while let Some(result) = connection.accept().await {
+        let (request, respond) = result?;
+        tokio::spawn(async move {
+            if let Err(e) = handle_request(request, respond).await {
+                println!("error while handling request: {}", e);
+            }
+        });
+    }
+    Ok(())
+}
+
+async fn handle_request(
+    mut request: Request<RecvStream>,
+    mut respond: SendResponse<Bytes>,
+) -> Result<(), Box<dyn Error + Send + Sync>> {
+    let body = request.body_mut();
+    while let Some(data) = body.data().await {
+        let data = data?;
+        let _ = body.flow_control().release_capacity(data.len());
+    }
+    let response = http::Response::new(());
+    let mut send = respond.send_response(response, false)?;
+    send.send_data(Bytes::from_static(b"pong"), true)?;
+
+    Ok(())
+}
+
+// The benchmark
+async fn send_requests(addr: &str) -> Result<(), Box<dyn Error>> {
+    let tcp = loop {
+        let Ok(tcp) = TcpStream::connect(addr).await else {
+            continue;
+        };
+        break tcp;
+    };
+    let (client, h2) = client::handshake(tcp).await?;
+    // Spawn a task to run the conn...
+    tokio::spawn(async move {
+        if let Err(e) = h2.await {
+            println!("GOT ERR={:?}", e);
+        }
+    });
+
+    let mut handles = Vec::with_capacity(NUM_REQUESTS_TO_SEND);
+    for _i in 0..NUM_REQUESTS_TO_SEND {
+        let mut client = client.clone();
+        let task = tokio::spawn(async move {
+            let request = Request::builder().body(()).unwrap();
+
+            let instant = Instant::now();
+            let (response, _) = client.send_request(request, true).unwrap();
+            let response = response.await.unwrap();
+            let mut body = response.into_body();
+            while let Some(_chunk) = body.data().await {}
+            instant.elapsed()
+        });
+        handles.push(task);
+    }
+
+    let instant = Instant::now();
+    let mut result = Vec::with_capacity(NUM_REQUESTS_TO_SEND);
+    for handle in handles {
+        result.push(handle.await.unwrap());
+    }
+    let mut sum = Duration::new(0, 0);
+    for r in result.iter() {
+        sum = sum.checked_add(*r).unwrap();
+    }
+
+    println!("Overall: {}ms.", instant.elapsed().as_millis());
+    println!("Fastest: {}ms", result.iter().min().unwrap().as_millis());
+    println!("Slowest: {}ms", result.iter().max().unwrap().as_millis());
+    println!(
+        "Avg    : {}ms",
+        sum.div_f64(NUM_REQUESTS_TO_SEND as f64).as_millis()
+    );
+    Ok(())
+}
+
+fn main() {
+    let _ = env_logger::try_init();
+    let addr = "127.0.0.1:5928";
+    println!("H2 running in current-thread runtime at {addr}:");
+    std::thread::spawn(|| {
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap();
+        rt.block_on(server(addr)).unwrap();
+    });
+
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()
+        .unwrap();
+    rt.block_on(send_requests(addr)).unwrap();
+
+    let addr = "127.0.0.1:5929";
+    println!("H2 running in multi-thread runtime at {addr}:");
+    std::thread::spawn(|| {
+        let rt = tokio::runtime::Builder::new_multi_thread()
+            .worker_threads(4)
+            .enable_all()
+            .build()
+            .unwrap();
+        rt.block_on(server(addr)).unwrap();
+    });
+
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()
+        .unwrap();
+    rt.block_on(send_requests(addr)).unwrap();
+}

vendor/h2/examples/akamai.rs

@@ -0,0 +1,72 @@
+use h2::client;
+use http::{Method, Request};
+use tokio::net::TcpStream;
+use tokio_rustls::TlsConnector;
+
+use tokio_rustls::rustls::{pki_types::ServerName, RootCertStore};
+
+use std::error::Error;
+use std::net::ToSocketAddrs;
+
+const ALPN_H2: &str = "h2";
+
+#[tokio::main]
+pub async fn main() -> Result<(), Box<dyn Error>> {
+    let _ = env_logger::try_init();
+
+    let tls_client_config = std::sync::Arc::new({
+        let root_store = RootCertStore::from_iter(webpki_roots::TLS_SERVER_ROOTS.iter().cloned());
+        let mut c = tokio_rustls::rustls::ClientConfig::builder()
+            .with_root_certificates(root_store)
+            .with_no_client_auth();
+        c.alpn_protocols.push(ALPN_H2.as_bytes().to_owned());
+        c
+    });
+
+    // Sync DNS resolution.
+    let addr = "http2.akamai.com:443"
+        .to_socket_addrs()
+        .unwrap()
+        .next()
+        .unwrap();
+
+    println!("ADDR: {:?}", addr);
+
+    let tcp = TcpStream::connect(&addr).await?;
+    let dns_name = ServerName::try_from("http2.akamai.com").unwrap();
+    let connector = TlsConnector::from(tls_client_config);
+    let res = connector.connect(dns_name, tcp).await;
+    let tls = res.unwrap();
+    {
+        let (_, session) = tls.get_ref();
+        let negotiated_protocol = session.alpn_protocol();
+        assert_eq!(Some(ALPN_H2.as_bytes()), negotiated_protocol);
+    }
+
+    println!("Starting client handshake");
+    let (mut client, h2) = client::handshake(tls).await?;
+
+    println!("building request");
+    let request = Request::builder()
+        .method(Method::GET)
+        .uri("https://http2.akamai.com/")
+        .body(())
+        .unwrap();
+
+    println!("sending request");
+    let (response, other) = client.send_request(request, true).unwrap();
+
+    tokio::spawn(async move {
+        if let Err(e) = h2.await {
+            println!("GOT ERR={:?}", e);
+        }
+    });
+
+    println!("waiting on response : {:?}", other);
+    let (_, mut body) = response.await?.into_parts();
+    println!("processing body");
+    while let Some(chunk) = body.data().await {
+        println!("RX: {:?}", chunk?);
+    }
+    Ok(())
+}

vendor/h2/examples/client.rs

@@ -0,0 +1,52 @@
+use h2::client;
+use http::{HeaderMap, Request};
+
+use std::error::Error;
+
+use tokio::net::TcpStream;
+
+#[tokio::main]
+pub async fn main() -> Result<(), Box<dyn Error>> {
+    let _ = env_logger::try_init();
+
+    let tcp = TcpStream::connect("127.0.0.1:5928").await?;
+    let (mut client, h2) = client::handshake(tcp).await?;
+
+    println!("sending request");
+
+    let request = Request::builder()
+        .uri("https://http2.akamai.com/")
+        .body(())
+        .unwrap();
+
+    let mut trailers = HeaderMap::new();
+    trailers.insert("zomg", "hello".parse().unwrap());
+
+    let (response, mut stream) = client.send_request(request, false).unwrap();
+
+    // send trailers
+    stream.send_trailers(trailers).unwrap();
+
+    // Spawn a task to run the conn...
+    tokio::spawn(async move {
+        if let Err(e) = h2.await {
+            println!("GOT ERR={:?}", e);
+        }
+    });
+
+    let response = response.await?;
+    println!("GOT RESPONSE: {:?}", response);
+
+    // Get the body
+    let mut body = response.into_body();
+
+    while let Some(chunk) = body.data().await {
+        println!("GOT CHUNK = {:?}", chunk?);
+    }
+
+    if let Some(trailers) = body.trailers().await? {
+        println!("GOT TRAILERS: {:?}", trailers);
+    }
+
+    Ok(())
+}

vendor/h2/examples/server.rs

@@ -0,0 +1,65 @@
+use std::error::Error;
+
+use bytes::Bytes;
+use h2::server::{self, SendResponse};
+use h2::RecvStream;
+use http::Request;
+use tokio::net::{TcpListener, TcpStream};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+    let _ = env_logger::try_init();
+
+    let listener = TcpListener::bind("127.0.0.1:5928").await?;
+
+    println!("listening on {:?}", listener.local_addr());
+
+    loop {
+        if let Ok((socket, _peer_addr)) = listener.accept().await {
+            tokio::spawn(async move {
+                if let Err(e) = serve(socket).await {
+                    println!("  -> err={:?}", e);
+                }
+            });
+        }
+    }
+}
+
+async fn serve(socket: TcpStream) -> Result<(), Box<dyn Error + Send + Sync>> {
+    let mut connection = server::handshake(socket).await?;
+    println!("H2 connection bound");
+
+    while let Some(result) = connection.accept().await {
+        let (request, respond) = result?;
+        tokio::spawn(async move {
+            if let Err(e) = handle_request(request, respond).await {
+                println!("error while handling request: {}", e);
+            }
+        });
+    }
+
+    println!("~~~~~~~~~~~ H2 connection CLOSE !!!!!! ~~~~~~~~~~~");
+    Ok(())
+}
+
+async fn handle_request(
+    mut request: Request<RecvStream>,
+    mut respond: SendResponse<Bytes>,
+) -> Result<(), Box<dyn Error + Send + Sync>> {
+    println!("GOT request: {:?}", request);
+
+    let body = request.body_mut();
+    while let Some(data) = body.data().await {
+        let data = data?;
+        println!("<<<< recv {:?}", data);
+        let _ = body.flow_control().release_capacity(data.len());
+    }
+
+    let response = http::Response::new(());
+    let mut send = respond.send_response(response, false)?;
+    println!(">>>> send");
+    send.send_data(Bytes::from_static(b"hello "), false)?;
+    send.send_data(Bytes::from_static(b"world\n"), true)?;
+
+    Ok(())
+}

vendor/h2/src/codec/error.rs

@@ -0,0 +1,106 @@
+use crate::proto::Error;
+
+use std::{error, fmt, io};
+
+/// Errors caused by sending a message
+#[derive(Debug)]
+pub enum SendError {
+    Connection(Error),
+    User(UserError),
+}
+
+/// Errors caused by users of the library
+#[derive(Debug)]
+pub enum UserError {
+    /// The stream ID is no longer accepting frames.
+    InactiveStreamId,
+
+    /// The stream is not currently expecting a frame of this type.
+    UnexpectedFrameType,
+
+    /// The payload size is too big
+    PayloadTooBig,
+
+    /// The application attempted to initiate too many streams to remote.
+    Rejected,
+
+    /// The released capacity is larger than claimed capacity.
+    ReleaseCapacityTooBig,
+
+    /// The stream ID space is overflowed.
+    ///
+    /// A new connection is needed.
+    OverflowedStreamId,
+
+    /// Illegal headers, such as connection-specific headers.
+    MalformedHeaders,
+
+    /// Request submitted with relative URI.
+    MissingUriSchemeAndAuthority,
+
+    /// Calls `SendResponse::poll_reset` after having called `send_response`.
+    PollResetAfterSendResponse,
+
+    /// Calls `PingPong::send_ping` before receiving a pong.
+    SendPingWhilePending,
+
+    /// Tries to update local SETTINGS while ACK has not been received.
+    SendSettingsWhilePending,
+
+    /// Tries to send push promise to peer who has disabled server push
+    PeerDisabledServerPush,
+
+    /// Invalid status code for informational response (must be 1xx)
+    InvalidInformationalStatusCode,
+}
+
+// ===== impl SendError =====
+
+impl error::Error for SendError {}
+
+impl fmt::Display for SendError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Self::Connection(ref e) => e.fmt(fmt),
+            Self::User(ref e) => e.fmt(fmt),
+        }
+    }
+}
+
+impl From<io::Error> for SendError {
+    fn from(src: io::Error) -> Self {
+        Self::Connection(src.into())
+    }
+}
+
+impl From<UserError> for SendError {
+    fn from(src: UserError) -> Self {
+        SendError::User(src)
+    }
+}
+
+// ===== impl UserError =====
+
+impl error::Error for UserError {}
+
+impl fmt::Display for UserError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        use self::UserError::*;
+
+        fmt.write_str(match *self {
+            InactiveStreamId => "inactive stream",
+            UnexpectedFrameType => "unexpected frame type",
+            PayloadTooBig => "payload too big",
+            Rejected => "rejected",
+            ReleaseCapacityTooBig => "release capacity too big",
+            OverflowedStreamId => "stream ID overflowed",
+            MalformedHeaders => "malformed headers",
+            MissingUriSchemeAndAuthority => "request URI missing scheme and authority",
+            PollResetAfterSendResponse => "poll_reset after send_response is illegal",
+            SendPingWhilePending => "send_ping before received previous pong",
+            SendSettingsWhilePending => "sending SETTINGS before received previous ACK",
+            PeerDisabledServerPush => "sending PUSH_PROMISE to peer who disabled server push",
+            InvalidInformationalStatusCode => "invalid informational status code",
+        })
+    }
+}

vendor/h2/src/codec/framed_read.rs

@@ -0,0 +1,465 @@
+use crate::frame::{self, Frame, Kind, Reason};
+use crate::frame::{
+    DEFAULT_MAX_FRAME_SIZE, DEFAULT_SETTINGS_HEADER_TABLE_SIZE, MAX_MAX_FRAME_SIZE,
+};
+use crate::proto::Error;
+
+use crate::hpack;
+
+use futures_core::Stream;
+
+use bytes::{Buf, BytesMut};
+
+use std::io;
+
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio::io::AsyncRead;
+use tokio_util::codec::FramedRead as InnerFramedRead;
+use tokio_util::codec::{LengthDelimitedCodec, LengthDelimitedCodecError};
+
+// 16 MB "sane default" taken from golang http2
+const DEFAULT_SETTINGS_MAX_HEADER_LIST_SIZE: usize = 16 << 20;
+
+#[derive(Debug)]
+pub struct FramedRead<T> {
+    inner: InnerFramedRead<T, LengthDelimitedCodec>,
+
+    // hpack decoder state
+    hpack: hpack::Decoder,
+
+    max_header_list_size: usize,
+
+    max_continuation_frames: usize,
+
+    partial: Option<Partial>,
+}
+
+/// Partially loaded headers frame
+#[derive(Debug)]
+struct Partial {
+    /// Empty frame
+    frame: Continuable,
+
+    /// Partial header payload
+    buf: BytesMut,
+
+    continuation_frames_count: usize,
+}
+
+#[derive(Debug)]
+enum Continuable {
+    Headers(frame::Headers),
+    PushPromise(frame::PushPromise),
+}
+
+impl<T> FramedRead<T> {
+    pub fn new(inner: InnerFramedRead<T, LengthDelimitedCodec>) -> FramedRead<T> {
+        let max_header_list_size = DEFAULT_SETTINGS_MAX_HEADER_LIST_SIZE;
+        let max_continuation_frames =
+            calc_max_continuation_frames(max_header_list_size, inner.decoder().max_frame_length());
+        FramedRead {
+            inner,
+            hpack: hpack::Decoder::new(DEFAULT_SETTINGS_HEADER_TABLE_SIZE),
+            max_header_list_size,
+            max_continuation_frames,
+            partial: None,
+        }
+    }
+
+    pub fn get_ref(&self) -> &T {
+        self.inner.get_ref()
+    }
+
+    pub fn get_mut(&mut self) -> &mut T {
+        self.inner.get_mut()
+    }
+
+    /// Returns the current max frame size setting
+    #[inline]
+    pub fn max_frame_size(&self) -> usize {
+        self.inner.decoder().max_frame_length()
+    }
+
+    /// Updates the max frame size setting.
+    ///
+    /// Must be within 16,384 and 16,777,215.
+    #[inline]
+    pub fn set_max_frame_size(&mut self, val: usize) {
+        assert!(DEFAULT_MAX_FRAME_SIZE as usize <= val && val <= MAX_MAX_FRAME_SIZE as usize);
+        self.inner.decoder_mut().set_max_frame_length(val);
+        // Update max CONTINUATION frames too, since its based on this
+        self.max_continuation_frames = calc_max_continuation_frames(self.max_header_list_size, val);
+    }
+
+    /// Update the max header list size setting.
+    #[inline]
+    pub fn set_max_header_list_size(&mut self, val: usize) {
+        self.max_header_list_size = val;
+        // Update max CONTINUATION frames too, since its based on this
+        self.max_continuation_frames = calc_max_continuation_frames(val, self.max_frame_size());
+    }
+
+    /// Update the header table size setting.
+    #[inline]
+    pub fn set_header_table_size(&mut self, val: usize) {
+        self.hpack.queue_size_update(val);
+    }
+}
+
+fn calc_max_continuation_frames(header_max: usize, frame_max: usize) -> usize {
+    // At least this many frames needed to use max header list size
+    let min_frames_for_list = (header_max / frame_max).max(1);
+    // Some padding for imperfectly packed frames
+    // 25% without floats
+    let padding = min_frames_for_list >> 2;
+    min_frames_for_list.saturating_add(padding).max(5)
+}
+
+/// Decodes a frame.
+///
+/// This method is intentionally de-generified and outlined because it is very large.
+fn decode_frame(
+    hpack: &mut hpack::Decoder,
+    max_header_list_size: usize,
+    max_continuation_frames: usize,
+    partial_inout: &mut Option<Partial>,
+    mut bytes: BytesMut,
+) -> Result<Option<Frame>, Error> {
+    let span = tracing::trace_span!("FramedRead::decode_frame", offset = bytes.len());
+    let _e = span.enter();
+
+    tracing::trace!("decoding frame from {}B", bytes.len());
+
+    // Parse the head
+    let head = frame::Head::parse(&bytes);
+
+    if partial_inout.is_some() && head.kind() != Kind::Continuation {
+        proto_err!(conn: "expected CONTINUATION, got {:?}", head.kind());
+        return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+    }
+
+    let kind = head.kind();
+
+    tracing::trace!(frame.kind = ?kind);
+
+    macro_rules! header_block {
+        ($frame:ident, $head:ident, $bytes:ident) => ({
+            // Drop the frame header
+            $bytes.advance(frame::HEADER_LEN);
+
+            // Parse the header frame w/o parsing the payload
+            let (mut frame, mut payload) = match frame::$frame::load($head, $bytes) {
+                Ok(res) => res,
+                Err(frame::Error::InvalidDependencyId) => {
+                    proto_err!(stream: "invalid HEADERS dependency ID");
+                    // A stream cannot depend on itself. An endpoint MUST
+                    // treat this as a stream error (Section 5.4.2) of type
+                    // `PROTOCOL_ERROR`.
+                    return Err(Error::library_reset($head.stream_id(), Reason::PROTOCOL_ERROR));
+                },
+                Err(e) => {
+                    proto_err!(conn: "failed to load frame; err={:?}", e);
+                    return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+                }
+            };
+
+            let is_end_headers = frame.is_end_headers();
+
+            // Load the HPACK encoded headers
+            match frame.load_hpack(&mut payload, max_header_list_size, hpack) {
+                Ok(_) => {},
+                Err(frame::Error::Hpack(hpack::DecoderError::NeedMore(_))) if !is_end_headers => {},
+                Err(frame::Error::MalformedMessage) => {
+                    let id = $head.stream_id();
+                    proto_err!(stream: "malformed header block; stream={:?}", id);
+                    return Err(Error::library_reset(id, Reason::PROTOCOL_ERROR));
+                },
+                Err(e) => {
+                    proto_err!(conn: "failed HPACK decoding; err={:?}", e);
+                    return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+                }
+            }
+
+            if is_end_headers {
+                frame.into()
+            } else {
+                tracing::trace!("loaded partial header block");
+                // Defer returning the frame
+                *partial_inout = Some(Partial {
+                    frame: Continuable::$frame(frame),
+                    buf: payload,
+                    continuation_frames_count: 0,
+                });
+
+                return Ok(None);
+            }
+        });
+    }
+
+    let frame = match kind {
+        Kind::Settings => {
+            let res = frame::Settings::load(head, &bytes[frame::HEADER_LEN..]);
+
+            res.map_err(|e| {
+                proto_err!(conn: "failed to load SETTINGS frame; err={:?}", e);
+                Error::library_go_away(Reason::PROTOCOL_ERROR)
+            })?
+            .into()
+        }
+        Kind::Ping => {
+            let res = frame::Ping::load(head, &bytes[frame::HEADER_LEN..]);
+
+            res.map_err(|e| {
+                proto_err!(conn: "failed to load PING frame; err={:?}", e);
+                Error::library_go_away(Reason::PROTOCOL_ERROR)
+            })?
+            .into()
+        }
+        Kind::WindowUpdate => {
+            let res = frame::WindowUpdate::load(head, &bytes[frame::HEADER_LEN..]);
+
+            res.map_err(|e| {
+                proto_err!(conn: "failed to load WINDOW_UPDATE frame; err={:?}", e);
+                Error::library_go_away(Reason::PROTOCOL_ERROR)
+            })?
+            .into()
+        }
+        Kind::Data => {
+            bytes.advance(frame::HEADER_LEN);
+            let res = frame::Data::load(head, bytes.freeze());
+
+            // TODO: Should this always be connection level? Probably not...
+            res.map_err(|e| {
+                proto_err!(conn: "failed to load DATA frame; err={:?}", e);
+                Error::library_go_away(Reason::PROTOCOL_ERROR)
+            })?
+            .into()
+        }
+        Kind::Headers => header_block!(Headers, head, bytes),
+        Kind::Reset => {
+            let res = frame::Reset::load(head, &bytes[frame::HEADER_LEN..]);
+            res.map_err(|e| {
+                proto_err!(conn: "failed to load RESET frame; err={:?}", e);
+                Error::library_go_away(Reason::PROTOCOL_ERROR)
+            })?
+            .into()
+        }
+        Kind::GoAway => {
+            let res = frame::GoAway::load(&bytes[frame::HEADER_LEN..]);
+            res.map_err(|e| {
+                proto_err!(conn: "failed to load GO_AWAY frame; err={:?}", e);
+                Error::library_go_away(Reason::PROTOCOL_ERROR)
+            })?
+            .into()
+        }
+        Kind::PushPromise => header_block!(PushPromise, head, bytes),
+        Kind::Priority => {
+            if head.stream_id() == 0 {
+                // Invalid stream identifier
+                proto_err!(conn: "invalid stream ID 0");
+                return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+            }
+
+            match frame::Priority::load(head, &bytes[frame::HEADER_LEN..]) {
+                Ok(frame) => frame.into(),
+                Err(frame::Error::InvalidDependencyId) => {
+                    // A stream cannot depend on itself. An endpoint MUST
+                    // treat this as a stream error (Section 5.4.2) of type
+                    // `PROTOCOL_ERROR`.
+                    let id = head.stream_id();
+                    proto_err!(stream: "PRIORITY invalid dependency ID; stream={:?}", id);
+                    return Err(Error::library_reset(id, Reason::PROTOCOL_ERROR));
+                }
+                Err(e) => {
+                    proto_err!(conn: "failed to load PRIORITY frame; err={:?};", e);
+                    return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+                }
+            }
+        }
+        Kind::Continuation => {
+            let is_end_headers = (head.flag() & 0x4) == 0x4;
+
+            let mut partial = match partial_inout.take() {
+                Some(partial) => partial,
+                None => {
+                    proto_err!(conn: "received unexpected CONTINUATION frame");
+                    return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+                }
+            };
+
+            // The stream identifiers must match
+            if partial.frame.stream_id() != head.stream_id() {
+                proto_err!(conn: "CONTINUATION frame stream ID does not match previous frame stream ID");
+                return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+            }
+
+            // Check for CONTINUATION flood
+            if is_end_headers {
+                partial.continuation_frames_count = 0;
+            } else {
+                let cnt = partial.continuation_frames_count + 1;
+                if cnt > max_continuation_frames {
+                    tracing::debug!("too_many_continuations, max = {}", max_continuation_frames);
+                    return Err(Error::library_go_away_data(
+                        Reason::ENHANCE_YOUR_CALM,
+                        "too_many_continuations",
+                    ));
+                } else {
+                    partial.continuation_frames_count = cnt;
+                }
+            }
+
+            // Extend the buf
+            if partial.buf.is_empty() {
+                partial.buf = bytes.split_off(frame::HEADER_LEN);
+            } else {
+                if partial.frame.is_over_size() {
+                    // If there was left over bytes previously, they may be
+                    // needed to continue decoding, even though we will
+                    // be ignoring this frame. This is done to keep the HPACK
+                    // decoder state up-to-date.
+                    //
+                    // Still, we need to be careful, because if a malicious
+                    // attacker were to try to send a gigantic string, such
+                    // that it fits over multiple header blocks, we could
+                    // grow memory uncontrollably again, and that'd be a shame.
+                    //
+                    // Instead, we use a simple heuristic to determine if
+                    // we should continue to ignore decoding, or to tell
+                    // the attacker to go away.
+                    if partial.buf.len() + bytes.len() > max_header_list_size {
+                        proto_err!(conn: "CONTINUATION frame header block size over ignorable limit");
+                        return Err(Error::library_go_away(Reason::COMPRESSION_ERROR));
+                    }
+                }
+                partial.buf.extend_from_slice(&bytes[frame::HEADER_LEN..]);
+            }
+
+            match partial
+                .frame
+                .load_hpack(&mut partial.buf, max_header_list_size, hpack)
+            {
+                Ok(_) => {}
+                Err(frame::Error::Hpack(hpack::DecoderError::NeedMore(_))) if !is_end_headers => {}
+                Err(frame::Error::MalformedMessage) => {
+                    let id = head.stream_id();
+                    proto_err!(stream: "malformed CONTINUATION frame; stream={:?}", id);
+                    return Err(Error::library_reset(id, Reason::PROTOCOL_ERROR));
+                }
+                Err(e) => {
+                    proto_err!(conn: "failed HPACK decoding; err={:?}", e);
+                    return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+                }
+            }
+
+            if is_end_headers {
+                partial.frame.into()
+            } else {
+                *partial_inout = Some(partial);
+                return Ok(None);
+            }
+        }
+        Kind::Unknown => {
+            // Unknown frames are ignored
+            return Ok(None);
+        }
+    };
+
+    Ok(Some(frame))
+}
+
+impl<T> Stream for FramedRead<T>
+where
+    T: AsyncRead + Unpin,
+{
+    type Item = Result<Frame, Error>;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let span = tracing::trace_span!("FramedRead::poll_next");
+        let _e = span.enter();
+        loop {
+            tracing::trace!("poll");
+            let bytes = match ready!(Pin::new(&mut self.inner).poll_next(cx)) {
+                Some(Ok(bytes)) => bytes,
+                Some(Err(e)) => return Poll::Ready(Some(Err(map_err(e)))),
+                None => return Poll::Ready(None),
+            };
+
+            tracing::trace!(read.bytes = bytes.len());
+            let Self {
+                ref mut hpack,
+                max_header_list_size,
+                ref mut partial,
+                max_continuation_frames,
+                ..
+            } = *self;
+            if let Some(frame) = decode_frame(
+                hpack,
+                max_header_list_size,
+                max_continuation_frames,
+                partial,
+                bytes,
+            )? {
+                tracing::debug!(?frame, "received");
+                return Poll::Ready(Some(Ok(frame)));
+            }
+        }
+    }
+}
+
+fn map_err(err: io::Error) -> Error {
+    if let io::ErrorKind::InvalidData = err.kind() {
+        if let Some(custom) = err.get_ref() {
+            if custom.is::<LengthDelimitedCodecError>() {
+                return Error::library_go_away(Reason::FRAME_SIZE_ERROR);
+            }
+        }
+    }
+    err.into()
+}
+
+// ===== impl Continuable =====
+
+impl Continuable {
+    fn stream_id(&self) -> frame::StreamId {
+        match *self {
+            Continuable::Headers(ref h) => h.stream_id(),
+            Continuable::PushPromise(ref p) => p.stream_id(),
+        }
+    }
+
+    fn is_over_size(&self) -> bool {
+        match *self {
+            Continuable::Headers(ref h) => h.is_over_size(),
+            Continuable::PushPromise(ref p) => p.is_over_size(),
+        }
+    }
+
+    fn load_hpack(
+        &mut self,
+        src: &mut BytesMut,
+        max_header_list_size: usize,
+        decoder: &mut hpack::Decoder,
+    ) -> Result<(), frame::Error> {
+        match *self {
+            Continuable::Headers(ref mut h) => h.load_hpack(src, max_header_list_size, decoder),
+            Continuable::PushPromise(ref mut p) => p.load_hpack(src, max_header_list_size, decoder),
+        }
+    }
+}
+
+impl<T> From<Continuable> for Frame<T> {
+    fn from(cont: Continuable) -> Self {
+        match cont {
+            Continuable::Headers(mut headers) => {
+                headers.set_end_headers();
+                headers.into()
+            }
+            Continuable::PushPromise(mut push) => {
+                push.set_end_headers();
+                push.into()
+            }
+        }
+    }
+}

vendor/h2/src/codec/framed_write.rs

@@ -0,0 +1,367 @@
+use crate::codec::UserError;
+use crate::codec::UserError::*;
+use crate::frame::{self, Frame, FrameSize};
+use crate::hpack;
+
+use bytes::{Buf, BufMut, BytesMut};
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
+use tokio_util::io::poll_write_buf;
+
+use std::io::{self, Cursor};
+
+// A macro to get around a method needing to borrow &mut self
+macro_rules! limited_write_buf {
+    ($self:expr) => {{
+        let limit = $self.max_frame_size() + frame::HEADER_LEN;
+        $self.buf.get_mut().limit(limit)
+    }};
+}
+
+#[derive(Debug)]
+pub struct FramedWrite<T, B> {
+    /// Upstream `AsyncWrite`
+    inner: T,
+    final_flush_done: bool,
+
+    encoder: Encoder<B>,
+}
+
+#[derive(Debug)]
+struct Encoder<B> {
+    /// HPACK encoder
+    hpack: hpack::Encoder,
+
+    /// Write buffer
+    ///
+    /// TODO: Should this be a ring buffer?
+    buf: Cursor<BytesMut>,
+
+    /// Next frame to encode
+    next: Option<Next<B>>,
+
+    /// Last data frame
+    last_data_frame: Option<frame::Data<B>>,
+
+    /// Max frame size, this is specified by the peer
+    max_frame_size: FrameSize,
+
+    /// Chain payloads bigger than this.
+    chain_threshold: usize,
+
+    /// Min buffer required to attempt to write a frame
+    min_buffer_capacity: usize,
+}
+
+#[derive(Debug)]
+enum Next<B> {
+    Data(frame::Data<B>),
+    Continuation(frame::Continuation),
+}
+
+/// Initialize the connection with this amount of write buffer.
+///
+/// The minimum MAX_FRAME_SIZE is 16kb, so always be able to send a HEADERS
+/// frame that big.
+const DEFAULT_BUFFER_CAPACITY: usize = 16 * 1_024;
+
+/// Chain payloads bigger than this when vectored I/O is enabled. The remote
+/// will never advertise a max frame size less than this (well, the spec says
+/// the max frame size can't be less than 16kb, so not even close).
+const CHAIN_THRESHOLD: usize = 256;
+
+/// Chain payloads bigger than this when vectored I/O is **not** enabled.
+/// A larger value in this scenario will reduce the number of small and
+/// fragmented data being sent, and hereby improve the throughput.
+const CHAIN_THRESHOLD_WITHOUT_VECTORED_IO: usize = 1024;
+
+// TODO: Make generic
+impl<T, B> FramedWrite<T, B>
+where
+    T: AsyncWrite + Unpin,
+    B: Buf,
+{
+    pub fn new(inner: T) -> FramedWrite<T, B> {
+        let chain_threshold = if inner.is_write_vectored() {
+            CHAIN_THRESHOLD
+        } else {
+            CHAIN_THRESHOLD_WITHOUT_VECTORED_IO
+        };
+        FramedWrite {
+            inner,
+            final_flush_done: false,
+            encoder: Encoder {
+                hpack: hpack::Encoder::default(),
+                buf: Cursor::new(BytesMut::with_capacity(DEFAULT_BUFFER_CAPACITY)),
+                next: None,
+                last_data_frame: None,
+                max_frame_size: frame::DEFAULT_MAX_FRAME_SIZE,
+                chain_threshold,
+                min_buffer_capacity: chain_threshold + frame::HEADER_LEN,
+            },
+        }
+    }
+
+    /// Returns `Ready` when `send` is able to accept a frame
+    ///
+    /// Calling this function may result in the current contents of the buffer
+    /// to be flushed to `T`.
+    pub fn poll_ready(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
+        if !self.encoder.has_capacity() {
+            // Try flushing
+            ready!(self.flush(cx))?;
+
+            if !self.encoder.has_capacity() {
+                return Poll::Pending;
+            }
+        }
+
+        Poll::Ready(Ok(()))
+    }
+
+    /// Buffer a frame.
+    ///
+    /// `poll_ready` must be called first to ensure that a frame may be
+    /// accepted.
+    pub fn buffer(&mut self, item: Frame<B>) -> Result<(), UserError> {
+        self.encoder.buffer(item)
+    }
+
+    /// Flush buffered data to the wire
+    pub fn flush(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
+        let span = tracing::trace_span!("FramedWrite::flush");
+        let _e = span.enter();
+
+        loop {
+            while !self.encoder.is_empty() {
+                match self.encoder.next {
+                    Some(Next::Data(ref mut frame)) => {
+                        tracing::trace!(queued_data_frame = true);
+                        let mut buf = (&mut self.encoder.buf).chain(frame.payload_mut());
+                        ready!(poll_write_buf(Pin::new(&mut self.inner), cx, &mut buf))?
+                    }
+                    _ => {
+                        tracing::trace!(queued_data_frame = false);
+                        ready!(poll_write_buf(
+                            Pin::new(&mut self.inner),
+                            cx,
+                            &mut self.encoder.buf
+                        ))?
+                    }
+                };
+            }
+
+            match self.encoder.unset_frame() {
+                ControlFlow::Continue => (),
+                ControlFlow::Break => break,
+            }
+        }
+
+        tracing::trace!("flushing buffer");
+        // Flush the upstream
+        ready!(Pin::new(&mut self.inner).poll_flush(cx))?;
+
+        Poll::Ready(Ok(()))
+    }
+
+    /// Close the codec
+    pub fn shutdown(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
+        if !self.final_flush_done {
+            ready!(self.flush(cx))?;
+            self.final_flush_done = true;
+        }
+        Pin::new(&mut self.inner).poll_shutdown(cx)
+    }
+}
+
+#[must_use]
+enum ControlFlow {
+    Continue,
+    Break,
+}
+
+impl<B> Encoder<B>
+where
+    B: Buf,
+{
+    fn unset_frame(&mut self) -> ControlFlow {
+        // Clear internal buffer
+        self.buf.set_position(0);
+        self.buf.get_mut().clear();
+
+        // The data frame has been written, so unset it
+        match self.next.take() {
+            Some(Next::Data(frame)) => {
+                self.last_data_frame = Some(frame);
+                debug_assert!(self.is_empty());
+                ControlFlow::Break
+            }
+            Some(Next::Continuation(frame)) => {
+                // Buffer the continuation frame, then try to write again
+                let mut buf = limited_write_buf!(self);
+                if let Some(continuation) = frame.encode(&mut buf) {
+                    self.next = Some(Next::Continuation(continuation));
+                }
+                ControlFlow::Continue
+            }
+            None => ControlFlow::Break,
+        }
+    }
+
+    fn buffer(&mut self, item: Frame<B>) -> Result<(), UserError> {
+        // Ensure that we have enough capacity to accept the write.
+        assert!(self.has_capacity());
+        let span = tracing::trace_span!("FramedWrite::buffer", frame = ?item);
+        let _e = span.enter();
+
+        tracing::debug!(frame = ?item, "send");
+
+        match item {
+            Frame::Data(mut v) => {
+                // Ensure that the payload is not greater than the max frame.
+                let len = v.payload().remaining();
+
+                if len > self.max_frame_size() {
+                    return Err(PayloadTooBig);
+                }
+
+                if len >= self.chain_threshold {
+                    let head = v.head();
+
+                    // Encode the frame head to the buffer
+                    head.encode(len, self.buf.get_mut());
+
+                    if self.buf.get_ref().remaining() < self.chain_threshold {
+                        let extra_bytes = self.chain_threshold - self.buf.remaining();
+                        self.buf.get_mut().put(v.payload_mut().take(extra_bytes));
+                    }
+
+                    // Save the data frame
+                    self.next = Some(Next::Data(v));
+                } else {
+                    v.encode_chunk(self.buf.get_mut());
+
+                    // The chunk has been fully encoded, so there is no need to
+                    // keep it around
+                    assert_eq!(v.payload().remaining(), 0, "chunk not fully encoded");
+
+                    // Save off the last frame...
+                    self.last_data_frame = Some(v);
+                }
+            }
+            Frame::Headers(v) => {
+                let mut buf = limited_write_buf!(self);
+                if let Some(continuation) = v.encode(&mut self.hpack, &mut buf) {
+                    self.next = Some(Next::Continuation(continuation));
+                }
+            }
+            Frame::PushPromise(v) => {
+                let mut buf = limited_write_buf!(self);
+                if let Some(continuation) = v.encode(&mut self.hpack, &mut buf) {
+                    self.next = Some(Next::Continuation(continuation));
+                }
+            }
+            Frame::Settings(v) => {
+                v.encode(self.buf.get_mut());
+                tracing::trace!(rem = self.buf.remaining(), "encoded settings");
+            }
+            Frame::GoAway(v) => {
+                v.encode(self.buf.get_mut());
+                tracing::trace!(rem = self.buf.remaining(), "encoded go_away");
+            }
+            Frame::Ping(v) => {
+                v.encode(self.buf.get_mut());
+                tracing::trace!(rem = self.buf.remaining(), "encoded ping");
+            }
+            Frame::WindowUpdate(v) => {
+                v.encode(self.buf.get_mut());
+                tracing::trace!(rem = self.buf.remaining(), "encoded window_update");
+            }
+
+            Frame::Priority(_) => {
+                /*
+                v.encode(self.buf.get_mut());
+                tracing::trace!("encoded priority; rem={:?}", self.buf.remaining());
+                */
+                unimplemented!();
+            }
+            Frame::Reset(v) => {
+                v.encode(self.buf.get_mut());
+                tracing::trace!(rem = self.buf.remaining(), "encoded reset");
+            }
+        }
+
+        Ok(())
+    }
+
+    fn has_capacity(&self) -> bool {
+        self.next.is_none()
+            && (self.buf.get_ref().capacity() - self.buf.get_ref().len()
+                >= self.min_buffer_capacity)
+    }
+
+    fn is_empty(&self) -> bool {
+        match self.next {
+            Some(Next::Data(ref frame)) => !frame.payload().has_remaining(),
+            _ => !self.buf.has_remaining(),
+        }
+    }
+}
+
+impl<B> Encoder<B> {
+    fn max_frame_size(&self) -> usize {
+        self.max_frame_size as usize
+    }
+}
+
+impl<T, B> FramedWrite<T, B> {
+    /// Returns the max frame size that can be sent
+    pub fn max_frame_size(&self) -> usize {
+        self.encoder.max_frame_size()
+    }
+
+    /// Set the peer's max frame size.
+    pub fn set_max_frame_size(&mut self, val: usize) {
+        assert!(val <= frame::MAX_MAX_FRAME_SIZE as usize);
+        self.encoder.max_frame_size = val as FrameSize;
+    }
+
+    /// Set the peer's header table size.
+    pub fn set_header_table_size(&mut self, val: usize) {
+        self.encoder.hpack.update_max_size(val);
+    }
+
+    /// Retrieve the last data frame that has been sent
+    pub fn take_last_data_frame(&mut self) -> Option<frame::Data<B>> {
+        self.encoder.last_data_frame.take()
+    }
+
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner
+    }
+}
+
+impl<T: AsyncRead + Unpin, B> AsyncRead for FramedWrite<T, B> {
+    fn poll_read(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf,
+    ) -> Poll<io::Result<()>> {
+        Pin::new(&mut self.inner).poll_read(cx, buf)
+    }
+}
+
+// We never project the Pin to `B`.
+impl<T: Unpin, B> Unpin for FramedWrite<T, B> {}
+
+#[cfg(feature = "unstable")]
+mod unstable {
+    use super::*;
+
+    impl<T, B> FramedWrite<T, B> {
+        pub fn get_ref(&self) -> &T {
+            &self.inner
+        }
+    }
+}

vendor/h2/src/codec/mod.rs

@@ -0,0 +1,206 @@
+mod error;
+mod framed_read;
+mod framed_write;
+
+pub use self::error::{SendError, UserError};
+
+use self::framed_read::FramedRead;
+use self::framed_write::FramedWrite;
+
+use crate::frame::{self, Data, Frame};
+use crate::proto::Error;
+
+use bytes::Buf;
+use futures_core::Stream;
+use futures_sink::Sink;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio::io::{AsyncRead, AsyncWrite};
+use tokio_util::codec::length_delimited;
+
+use std::io;
+
+#[derive(Debug)]
+pub struct Codec<T, B> {
+    inner: FramedRead<FramedWrite<T, B>>,
+}
+
+impl<T, B> Codec<T, B>
+where
+    T: AsyncRead + AsyncWrite + Unpin,
+    B: Buf,
+{
+    /// Returns a new `Codec` with the default max frame size
+    #[inline]
+    pub fn new(io: T) -> Self {
+        Self::with_max_recv_frame_size(io, frame::DEFAULT_MAX_FRAME_SIZE as usize)
+    }
+
+    /// Returns a new `Codec` with the given maximum frame size
+    pub fn with_max_recv_frame_size(io: T, max_frame_size: usize) -> Self {
+        // Wrap with writer
+        let framed_write = FramedWrite::new(io);
+
+        // Delimit the frames
+        let delimited = length_delimited::Builder::new()
+            .big_endian()
+            .length_field_length(3)
+            .length_adjustment(9)
+            .num_skip(0) // Don't skip the header
+            .new_read(framed_write);
+
+        let mut inner = FramedRead::new(delimited);
+
+        // Use FramedRead's method since it checks the value is within range.
+        inner.set_max_frame_size(max_frame_size);
+
+        Codec { inner }
+    }
+}
+
+impl<T, B> Codec<T, B> {
+    /// Updates the max received frame size.
+    ///
+    /// The change takes effect the next time a frame is decoded. In other
+    /// words, if a frame is currently in process of being decoded with a frame
+    /// size greater than `val` but less than the max frame size in effect
+    /// before calling this function, then the frame will be allowed.
+    #[inline]
+    pub fn set_max_recv_frame_size(&mut self, val: usize) {
+        self.inner.set_max_frame_size(val)
+    }
+
+    /// Returns the current max received frame size setting.
+    ///
+    /// This is the largest size this codec will accept from the wire. Larger
+    /// frames will be rejected.
+    #[cfg(feature = "unstable")]
+    #[inline]
+    pub fn max_recv_frame_size(&self) -> usize {
+        self.inner.max_frame_size()
+    }
+
+    /// Returns the max frame size that can be sent to the peer.
+    pub fn max_send_frame_size(&self) -> usize {
+        self.inner.get_ref().max_frame_size()
+    }
+
+    /// Set the peer's max frame size.
+    pub fn set_max_send_frame_size(&mut self, val: usize) {
+        self.framed_write().set_max_frame_size(val)
+    }
+
+    /// Set the peer's header table size size.
+    pub fn set_send_header_table_size(&mut self, val: usize) {
+        self.framed_write().set_header_table_size(val)
+    }
+
+    /// Set the decoder header table size size.
+    pub fn set_recv_header_table_size(&mut self, val: usize) {
+        self.inner.set_header_table_size(val)
+    }
+
+    /// Set the max header list size that can be received.
+    pub fn set_max_recv_header_list_size(&mut self, val: usize) {
+        self.inner.set_max_header_list_size(val);
+    }
+
+    /// Get a reference to the inner stream.
+    #[cfg(feature = "unstable")]
+    pub fn get_ref(&self) -> &T {
+        self.inner.get_ref().get_ref()
+    }
+
+    /// Get a mutable reference to the inner stream.
+    pub fn get_mut(&mut self) -> &mut T {
+        self.inner.get_mut().get_mut()
+    }
+
+    /// Takes the data payload value that was fully written to the socket
+    pub(crate) fn take_last_data_frame(&mut self) -> Option<Data<B>> {
+        self.framed_write().take_last_data_frame()
+    }
+
+    fn framed_write(&mut self) -> &mut FramedWrite<T, B> {
+        self.inner.get_mut()
+    }
+}
+
+impl<T, B> Codec<T, B>
+where
+    T: AsyncWrite + Unpin,
+    B: Buf,
+{
+    /// Returns `Ready` when the codec can buffer a frame
+    pub fn poll_ready(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
+        self.framed_write().poll_ready(cx)
+    }
+
+    /// Buffer a frame.
+    ///
+    /// `poll_ready` must be called first to ensure that a frame may be
+    /// accepted.
+    ///
+    /// TODO: Rename this to avoid conflicts with Sink::buffer
+    pub fn buffer(&mut self, item: Frame<B>) -> Result<(), UserError> {
+        self.framed_write().buffer(item)
+    }
+
+    /// Flush buffered data to the wire
+    pub fn flush(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
+        self.framed_write().flush(cx)
+    }
+
+    /// Shutdown the send half
+    pub fn shutdown(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
+        self.framed_write().shutdown(cx)
+    }
+}
+
+impl<T, B> Stream for Codec<T, B>
+where
+    T: AsyncRead + Unpin,
+{
+    type Item = Result<Frame, Error>;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        Pin::new(&mut self.inner).poll_next(cx)
+    }
+}
+
+impl<T, B> Sink<Frame<B>> for Codec<T, B>
+where
+    T: AsyncWrite + Unpin,
+    B: Buf,
+{
+    type Error = SendError;
+
+    fn start_send(mut self: Pin<&mut Self>, item: Frame<B>) -> Result<(), Self::Error> {
+        Codec::buffer(&mut self, item)?;
+        Ok(())
+    }
+    /// Returns `Ready` when the codec can buffer a frame
+    fn poll_ready(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.framed_write().poll_ready(cx).map_err(Into::into)
+    }
+
+    /// Flush buffered data to the wire
+    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.framed_write().flush(cx).map_err(Into::into)
+    }
+
+    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        ready!(self.shutdown(cx))?;
+        Poll::Ready(Ok(()))
+    }
+}
+
+// TODO: remove (or improve) this
+impl<T> From<T> for Codec<T, bytes::Bytes>
+where
+    T: AsyncRead + AsyncWrite + Unpin,
+{
+    fn from(src: T) -> Self {
+        Self::new(src)
+    }
+}

vendor/h2/src/error.rs

@@ -0,0 +1,211 @@
+use crate::codec::{SendError, UserError};
+use crate::frame::StreamId;
+use crate::proto::{self, Initiator};
+
+use bytes::Bytes;
+use std::{error, fmt, io};
+
+pub use crate::frame::Reason;
+
+/// Represents HTTP/2 operation errors.
+///
+/// `Error` covers error cases raised by protocol errors caused by the
+/// peer, I/O (transport) errors, and errors caused by the user of the library.
+///
+/// If the error was caused by the remote peer, then it will contain a
+/// [`Reason`] which can be obtained with the [`reason`] function.
+///
+/// [`Reason`]: struct.Reason.html
+/// [`reason`]: #method.reason
+#[derive(Debug)]
+pub struct Error {
+    kind: Kind,
+}
+
+#[derive(Debug)]
+enum Kind {
+    /// A RST_STREAM frame was received or sent.
+    #[allow(dead_code)]
+    Reset(StreamId, Reason, Initiator),
+
+    /// A GO_AWAY frame was received or sent.
+    GoAway(Bytes, Reason, Initiator),
+
+    /// The user created an error from a bare Reason.
+    Reason(Reason),
+
+    /// An error resulting from an invalid action taken by the user of this
+    /// library.
+    User(UserError),
+
+    /// An `io::Error` occurred while trying to read or write.
+    Io(io::Error),
+}
+
+// ===== impl Error =====
+
+impl Error {
+    /// If the error was caused by the remote peer, the error reason.
+    ///
+    /// This is either an error received by the peer or caused by an invalid
+    /// action taken by the peer (i.e. a protocol error).
+    pub fn reason(&self) -> Option<Reason> {
+        match self.kind {
+            Kind::Reset(_, reason, _) | Kind::GoAway(_, reason, _) | Kind::Reason(reason) => {
+                Some(reason)
+            }
+            _ => None,
+        }
+    }
+
+    /// Returns true if the error is an io::Error
+    pub fn is_io(&self) -> bool {
+        matches!(self.kind, Kind::Io(..))
+    }
+
+    /// Returns the error if the error is an io::Error
+    pub fn get_io(&self) -> Option<&io::Error> {
+        match self.kind {
+            Kind::Io(ref e) => Some(e),
+            _ => None,
+        }
+    }
+
+    /// Returns the error if the error is an io::Error
+    pub fn into_io(self) -> Option<io::Error> {
+        match self.kind {
+            Kind::Io(e) => Some(e),
+            _ => None,
+        }
+    }
+
+    pub(crate) fn from_io(err: io::Error) -> Self {
+        Error {
+            kind: Kind::Io(err),
+        }
+    }
+
+    /// Returns true if the error is from a `GOAWAY`.
+    pub fn is_go_away(&self) -> bool {
+        matches!(self.kind, Kind::GoAway(..))
+    }
+
+    /// Returns true if the error is from a `RST_STREAM`.
+    pub fn is_reset(&self) -> bool {
+        matches!(self.kind, Kind::Reset(..))
+    }
+
+    /// Returns true if the error was received in a frame from the remote.
+    ///
+    /// Such as from a received `RST_STREAM` or `GOAWAY` frame.
+    pub fn is_remote(&self) -> bool {
+        matches!(
+            self.kind,
+            Kind::GoAway(_, _, Initiator::Remote) | Kind::Reset(_, _, Initiator::Remote)
+        )
+    }
+
+    /// Returns true if the error was created by `h2`.
+    ///
+    /// Such as noticing some protocol error and sending a GOAWAY or RST_STREAM.
+    pub fn is_library(&self) -> bool {
+        matches!(
+            self.kind,
+            Kind::GoAway(_, _, Initiator::Library) | Kind::Reset(_, _, Initiator::Library)
+        )
+    }
+}
+
+impl From<proto::Error> for Error {
+    fn from(src: proto::Error) -> Error {
+        use crate::proto::Error::*;
+
+        Error {
+            kind: match src {
+                Reset(stream_id, reason, initiator) => Kind::Reset(stream_id, reason, initiator),
+                GoAway(debug_data, reason, initiator) => {
+                    Kind::GoAway(debug_data, reason, initiator)
+                }
+                Io(kind, inner) => {
+                    Kind::Io(inner.map_or_else(|| kind.into(), |inner| io::Error::new(kind, inner)))
+                }
+            },
+        }
+    }
+}
+
+impl From<Reason> for Error {
+    fn from(src: Reason) -> Error {
+        Error {
+            kind: Kind::Reason(src),
+        }
+    }
+}
+
+impl From<SendError> for Error {
+    fn from(src: SendError) -> Error {
+        match src {
+            SendError::User(e) => e.into(),
+            SendError::Connection(e) => e.into(),
+        }
+    }
+}
+
+impl From<UserError> for Error {
+    fn from(src: UserError) -> Error {
+        Error {
+            kind: Kind::User(src),
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        let debug_data = match self.kind {
+            Kind::Reset(_, reason, Initiator::User) => {
+                return write!(fmt, "stream error sent by user: {}", reason)
+            }
+            Kind::Reset(_, reason, Initiator::Library) => {
+                return write!(fmt, "stream error detected: {}", reason)
+            }
+            Kind::Reset(_, reason, Initiator::Remote) => {
+                return write!(fmt, "stream error received: {}", reason)
+            }
+            Kind::GoAway(ref debug_data, reason, Initiator::User) => {
+                write!(fmt, "connection error sent by user: {}", reason)?;
+                debug_data
+            }
+            Kind::GoAway(ref debug_data, reason, Initiator::Library) => {
+                write!(fmt, "connection error detected: {}", reason)?;
+                debug_data
+            }
+            Kind::GoAway(ref debug_data, reason, Initiator::Remote) => {
+                write!(fmt, "connection error received: {}", reason)?;
+                debug_data
+            }
+            Kind::Reason(reason) => return write!(fmt, "protocol error: {}", reason),
+            Kind::User(ref e) => return write!(fmt, "user error: {}", e),
+            Kind::Io(ref e) => return e.fmt(fmt),
+        };
+
+        if !debug_data.is_empty() {
+            write!(fmt, " ({:?})", debug_data)?;
+        }
+
+        Ok(())
+    }
+}
+
+impl error::Error for Error {}
+
+#[cfg(test)]
+mod tests {
+    use super::Error;
+    use crate::Reason;
+
+    #[test]
+    fn error_from_reason() {
+        let err = Error::from(Reason::HTTP_1_1_REQUIRED);
+        assert_eq!(err.reason(), Some(Reason::HTTP_1_1_REQUIRED));
+    }
+}

vendor/h2/src/ext.rs

@@ -0,0 +1,55 @@
+//! Extensions specific to the HTTP/2 protocol.
+
+use crate::hpack::BytesStr;
+
+use bytes::Bytes;
+use std::fmt;
+
+/// Represents the `:protocol` pseudo-header used by
+/// the [Extended CONNECT Protocol].
+///
+/// [Extended CONNECT Protocol]: https://datatracker.ietf.org/doc/html/rfc8441#section-4
+#[derive(Clone, Eq, PartialEq)]
+pub struct Protocol {
+    value: BytesStr,
+}
+
+impl Protocol {
+    /// Converts a static string to a protocol name.
+    pub const fn from_static(value: &'static str) -> Self {
+        Self {
+            value: BytesStr::from_static(value),
+        }
+    }
+
+    /// Returns a str representation of the header.
+    pub fn as_str(&self) -> &str {
+        self.value.as_str()
+    }
+
+    pub(crate) fn try_from(bytes: Bytes) -> Result<Self, std::str::Utf8Error> {
+        Ok(Self {
+            value: BytesStr::try_from(bytes)?,
+        })
+    }
+}
+
+impl<'a> From<&'a str> for Protocol {
+    fn from(value: &'a str) -> Self {
+        Self {
+            value: BytesStr::from(value),
+        }
+    }
+}
+
+impl AsRef<[u8]> for Protocol {
+    fn as_ref(&self) -> &[u8] {
+        self.value.as_ref()
+    }
+}
+
+impl fmt::Debug for Protocol {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.value.fmt(f)
+    }
+}

vendor/h2/src/frame/data.rs

@@ -0,0 +1,241 @@
+use crate::frame::{util, Error, Frame, Head, Kind, StreamId};
+use bytes::{Buf, BufMut, Bytes};
+
+use std::fmt;
+
+/// Data frame
+///
+/// Data frames convey arbitrary, variable-length sequences of octets associated
+/// with a stream. One or more DATA frames are used, for instance, to carry HTTP
+/// request or response payloads.
+#[derive(Eq, PartialEq)]
+pub struct Data<T = Bytes> {
+    stream_id: StreamId,
+    data: T,
+    flags: DataFlags,
+    pad_len: Option<u8>,
+}
+
+#[derive(Copy, Clone, Default, Eq, PartialEq)]
+struct DataFlags(u8);
+
+const END_STREAM: u8 = 0x1;
+const PADDED: u8 = 0x8;
+const ALL: u8 = END_STREAM | PADDED;
+
+impl<T> Data<T> {
+    /// Creates a new DATA frame.
+    pub fn new(stream_id: StreamId, payload: T) -> Self {
+        assert!(!stream_id.is_zero());
+
+        Data {
+            stream_id,
+            data: payload,
+            flags: DataFlags::default(),
+            pad_len: None,
+        }
+    }
+
+    /// Returns the stream identifier that this frame is associated with.
+    ///
+    /// This cannot be a zero stream identifier.
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    /// Gets the value of the `END_STREAM` flag for this frame.
+    ///
+    /// If true, this frame is the last that the endpoint will send for the
+    /// identified stream.
+    ///
+    /// Setting this flag causes the stream to enter one of the "half-closed"
+    /// states or the "closed" state (Section 5.1).
+    pub fn is_end_stream(&self) -> bool {
+        self.flags.is_end_stream()
+    }
+
+    /// Sets the value for the `END_STREAM` flag on this frame.
+    pub fn set_end_stream(&mut self, val: bool) {
+        if val {
+            self.flags.set_end_stream();
+        } else {
+            self.flags.unset_end_stream();
+        }
+    }
+
+    /// Returns whether the `PADDED` flag is set on this frame.
+    #[cfg(feature = "unstable")]
+    pub fn is_padded(&self) -> bool {
+        self.flags.is_padded()
+    }
+
+    /// Sets the value for the `PADDED` flag on this frame.
+    #[cfg(feature = "unstable")]
+    pub fn set_padded(&mut self) {
+        self.flags.set_padded();
+    }
+
+    /// Returns a reference to this frame's payload.
+    ///
+    /// This does **not** include any padding that might have been originally
+    /// included.
+    pub fn payload(&self) -> &T {
+        &self.data
+    }
+
+    /// Returns a mutable reference to this frame's payload.
+    ///
+    /// This does **not** include any padding that might have been originally
+    /// included.
+    pub fn payload_mut(&mut self) -> &mut T {
+        &mut self.data
+    }
+
+    /// Consumes `self` and returns the frame's payload.
+    ///
+    /// This does **not** include any padding that might have been originally
+    /// included.
+    pub fn into_payload(self) -> T {
+        self.data
+    }
+
+    pub(crate) fn head(&self) -> Head {
+        Head::new(Kind::Data, self.flags.into(), self.stream_id)
+    }
+
+    pub(crate) fn map<F, U>(self, f: F) -> Data<U>
+    where
+        F: FnOnce(T) -> U,
+    {
+        Data {
+            stream_id: self.stream_id,
+            data: f(self.data),
+            flags: self.flags,
+            pad_len: self.pad_len,
+        }
+    }
+}
+
+impl Data<Bytes> {
+    pub(crate) fn load(head: Head, mut payload: Bytes) -> Result<Self, Error> {
+        let flags = DataFlags::load(head.flag());
+
+        // The stream identifier must not be zero
+        if head.stream_id().is_zero() {
+            return Err(Error::InvalidStreamId);
+        }
+
+        let pad_len = if flags.is_padded() {
+            let len = util::strip_padding(&mut payload)?;
+            Some(len)
+        } else {
+            None
+        };
+
+        Ok(Data {
+            stream_id: head.stream_id(),
+            data: payload,
+            flags,
+            pad_len,
+        })
+    }
+
+    pub(crate) fn flow_controlled_len(&self) -> usize {
+        if let Some(pad_len) = self.pad_len {
+            // if PADDED, pad length field counts too (the + 1)
+            self.data.len() + usize::from(pad_len) + 1
+        } else {
+            self.data.len()
+        }
+    }
+
+    /// If this frame is PADDED, it returns the pad len + 1 (length field).
+    pub(crate) fn padded_len(&self) -> Option<u8> {
+        self.pad_len.map(|n| n + 1)
+    }
+}
+
+impl<T: Buf> Data<T> {
+    /// Encode the data frame into the `dst` buffer.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `dst` cannot contain the data frame.
+    pub(crate) fn encode_chunk<U: BufMut>(&mut self, dst: &mut U) {
+        let len = self.data.remaining();
+
+        assert!(dst.remaining_mut() >= len);
+
+        self.head().encode(len, dst);
+        dst.put(&mut self.data);
+    }
+}
+
+impl<T> From<Data<T>> for Frame<T> {
+    fn from(src: Data<T>) -> Self {
+        Frame::Data(src)
+    }
+}
+
+impl<T> fmt::Debug for Data<T> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        let mut f = fmt.debug_struct("Data");
+        f.field("stream_id", &self.stream_id);
+        if !self.flags.is_empty() {
+            f.field("flags", &self.flags);
+        }
+        if let Some(ref pad_len) = self.pad_len {
+            f.field("pad_len", pad_len);
+        }
+        // `data` bytes purposefully excluded
+        f.finish()
+    }
+}
+
+// ===== impl DataFlags =====
+
+impl DataFlags {
+    fn load(bits: u8) -> DataFlags {
+        DataFlags(bits & ALL)
+    }
+
+    fn is_empty(&self) -> bool {
+        self.0 == 0
+    }
+
+    fn is_end_stream(&self) -> bool {
+        self.0 & END_STREAM == END_STREAM
+    }
+
+    fn set_end_stream(&mut self) {
+        self.0 |= END_STREAM
+    }
+
+    fn unset_end_stream(&mut self) {
+        self.0 &= !END_STREAM
+    }
+
+    fn is_padded(&self) -> bool {
+        self.0 & PADDED == PADDED
+    }
+
+    #[cfg(feature = "unstable")]
+    fn set_padded(&mut self) {
+        self.0 |= PADDED
+    }
+}
+
+impl From<DataFlags> for u8 {
+    fn from(src: DataFlags) -> u8 {
+        src.0
+    }
+}
+
+impl fmt::Debug for DataFlags {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        util::debug_flags(fmt, self.0)
+            .flag_if(self.is_end_stream(), "END_STREAM")
+            .flag_if(self.is_padded(), "PADDED")
+            .finish()
+    }
+}

vendor/h2/src/frame/go_away.rs

@@ -0,0 +1,87 @@
+use std::fmt;
+
+use bytes::{BufMut, Bytes};
+
+use crate::frame::{self, Error, Head, Kind, Reason, StreamId};
+
+#[derive(Clone, Eq, PartialEq)]
+pub struct GoAway {
+    last_stream_id: StreamId,
+    error_code: Reason,
+    debug_data: Bytes,
+}
+
+impl GoAway {
+    pub fn new(last_stream_id: StreamId, reason: Reason) -> Self {
+        GoAway {
+            last_stream_id,
+            error_code: reason,
+            debug_data: Bytes::new(),
+        }
+    }
+
+    pub fn with_debug_data(last_stream_id: StreamId, reason: Reason, debug_data: Bytes) -> Self {
+        Self {
+            last_stream_id,
+            error_code: reason,
+            debug_data,
+        }
+    }
+
+    pub fn last_stream_id(&self) -> StreamId {
+        self.last_stream_id
+    }
+
+    pub fn reason(&self) -> Reason {
+        self.error_code
+    }
+
+    pub fn debug_data(&self) -> &Bytes {
+        &self.debug_data
+    }
+
+    pub fn load(payload: &[u8]) -> Result<GoAway, Error> {
+        if payload.len() < 8 {
+            return Err(Error::BadFrameSize);
+        }
+
+        let (last_stream_id, _) = StreamId::parse(&payload[..4]);
+        let error_code = unpack_octets_4!(payload, 4, u32);
+        let debug_data = Bytes::copy_from_slice(&payload[8..]);
+
+        Ok(GoAway {
+            last_stream_id,
+            error_code: error_code.into(),
+            debug_data,
+        })
+    }
+
+    pub fn encode<B: BufMut>(&self, dst: &mut B) {
+        tracing::trace!("encoding GO_AWAY; code={:?}", self.error_code);
+        let head = Head::new(Kind::GoAway, 0, StreamId::zero());
+        head.encode(8 + self.debug_data.len(), dst);
+        dst.put_u32(self.last_stream_id.into());
+        dst.put_u32(self.error_code.into());
+        dst.put(self.debug_data.slice(..));
+    }
+}
+
+impl<B> From<GoAway> for frame::Frame<B> {
+    fn from(src: GoAway) -> Self {
+        frame::Frame::GoAway(src)
+    }
+}
+
+impl fmt::Debug for GoAway {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut builder = f.debug_struct("GoAway");
+        builder.field("error_code", &self.error_code);
+        builder.field("last_stream_id", &self.last_stream_id);
+
+        if !self.debug_data.is_empty() {
+            builder.field("debug_data", &self.debug_data);
+        }
+
+        builder.finish()
+    }
+}

vendor/h2/src/frame/head.rs

@@ -0,0 +1,94 @@
+use super::StreamId;
+
+use bytes::BufMut;
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub struct Head {
+    kind: Kind,
+    flag: u8,
+    stream_id: StreamId,
+}
+
+#[repr(u8)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum Kind {
+    Data = 0,
+    Headers = 1,
+    Priority = 2,
+    Reset = 3,
+    Settings = 4,
+    PushPromise = 5,
+    Ping = 6,
+    GoAway = 7,
+    WindowUpdate = 8,
+    Continuation = 9,
+    Unknown,
+}
+
+// ===== impl Head =====
+
+impl Head {
+    pub fn new(kind: Kind, flag: u8, stream_id: StreamId) -> Head {
+        Head {
+            kind,
+            flag,
+            stream_id,
+        }
+    }
+
+    /// Parse an HTTP/2 frame header
+    pub fn parse(header: &[u8]) -> Head {
+        let (stream_id, _) = StreamId::parse(&header[5..]);
+
+        Head {
+            kind: Kind::new(header[3]),
+            flag: header[4],
+            stream_id,
+        }
+    }
+
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    pub fn kind(&self) -> Kind {
+        self.kind
+    }
+
+    pub fn flag(&self) -> u8 {
+        self.flag
+    }
+
+    pub fn encode_len(&self) -> usize {
+        super::HEADER_LEN
+    }
+
+    pub fn encode<T: BufMut>(&self, payload_len: usize, dst: &mut T) {
+        debug_assert!(self.encode_len() <= dst.remaining_mut());
+
+        dst.put_uint(payload_len as u64, 3);
+        dst.put_u8(self.kind as u8);
+        dst.put_u8(self.flag);
+        dst.put_u32(self.stream_id.into());
+    }
+}
+
+// ===== impl Kind =====
+
+impl Kind {
+    pub fn new(byte: u8) -> Kind {
+        match byte {
+            0 => Kind::Data,
+            1 => Kind::Headers,
+            2 => Kind::Priority,
+            3 => Kind::Reset,
+            4 => Kind::Settings,
+            5 => Kind::PushPromise,
+            6 => Kind::Ping,
+            7 => Kind::GoAway,
+            8 => Kind::WindowUpdate,
+            9 => Kind::Continuation,
+            _ => Kind::Unknown,
+        }
+    }
+}

vendor/h2/src/frame/mod.rs

@@ -0,0 +1,171 @@
+use crate::hpack;
+
+use bytes::Bytes;
+
+use std::fmt;
+
+/// A helper macro that unpacks a sequence of 4 bytes found in the buffer with
+/// the given identifier, starting at the given offset, into the given integer
+/// type. Obviously, the integer type should be able to support at least 4
+/// bytes.
+///
+/// # Examples
+///
+/// ```ignore
+/// # // We ignore this doctest because the macro is not exported.
+/// let buf: [u8; 4] = [0, 0, 0, 1];
+/// assert_eq!(1u32, unpack_octets_4!(buf, 0, u32));
+/// ```
+macro_rules! unpack_octets_4 {
+    // TODO: Get rid of this macro
+    ($buf:expr, $offset:expr, $tip:ty) => {
+        (($buf[$offset + 0] as $tip) << 24)
+            | (($buf[$offset + 1] as $tip) << 16)
+            | (($buf[$offset + 2] as $tip) << 8)
+            | (($buf[$offset + 3] as $tip) << 0)
+    };
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_unpack_octets_4() {
+        let buf: [u8; 4] = [0, 0, 0, 1];
+        assert_eq!(1u32, unpack_octets_4!(buf, 0, u32));
+    }
+}
+
+mod data;
+mod go_away;
+mod head;
+mod headers;
+mod ping;
+mod priority;
+mod reason;
+mod reset;
+mod settings;
+mod stream_id;
+mod util;
+mod window_update;
+
+pub use self::data::Data;
+pub use self::go_away::GoAway;
+pub use self::head::{Head, Kind};
+pub use self::headers::{
+    parse_u64, Continuation, Headers, Pseudo, PushPromise, PushPromiseHeaderError,
+};
+pub use self::ping::Ping;
+pub use self::priority::{Priority, StreamDependency};
+pub use self::reason::Reason;
+pub use self::reset::Reset;
+pub use self::settings::Settings;
+pub use self::stream_id::{StreamId, StreamIdOverflow};
+pub use self::window_update::WindowUpdate;
+
+#[cfg(feature = "unstable")]
+pub use crate::hpack::BytesStr;
+
+// Re-export some constants
+
+pub use self::settings::{
+    DEFAULT_INITIAL_WINDOW_SIZE, DEFAULT_MAX_FRAME_SIZE, DEFAULT_SETTINGS_HEADER_TABLE_SIZE,
+    MAX_MAX_FRAME_SIZE,
+};
+
+pub type FrameSize = u32;
+
+pub const HEADER_LEN: usize = 9;
+
+#[derive(Eq, PartialEq)]
+pub enum Frame<T = Bytes> {
+    Data(Data<T>),
+    Headers(Headers),
+    Priority(Priority),
+    PushPromise(PushPromise),
+    Settings(Settings),
+    Ping(Ping),
+    GoAway(GoAway),
+    WindowUpdate(WindowUpdate),
+    Reset(Reset),
+}
+
+impl<T> Frame<T> {
+    pub fn map<F, U>(self, f: F) -> Frame<U>
+    where
+        F: FnOnce(T) -> U,
+    {
+        use self::Frame::*;
+
+        match self {
+            Data(frame) => frame.map(f).into(),
+            Headers(frame) => frame.into(),
+            Priority(frame) => frame.into(),
+            PushPromise(frame) => frame.into(),
+            Settings(frame) => frame.into(),
+            Ping(frame) => frame.into(),
+            GoAway(frame) => frame.into(),
+            WindowUpdate(frame) => frame.into(),
+            Reset(frame) => frame.into(),
+        }
+    }
+}
+
+impl<T> fmt::Debug for Frame<T> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        use self::Frame::*;
+
+        match *self {
+            Data(ref frame) => fmt::Debug::fmt(frame, fmt),
+            Headers(ref frame) => fmt::Debug::fmt(frame, fmt),
+            Priority(ref frame) => fmt::Debug::fmt(frame, fmt),
+            PushPromise(ref frame) => fmt::Debug::fmt(frame, fmt),
+            Settings(ref frame) => fmt::Debug::fmt(frame, fmt),
+            Ping(ref frame) => fmt::Debug::fmt(frame, fmt),
+            GoAway(ref frame) => fmt::Debug::fmt(frame, fmt),
+            WindowUpdate(ref frame) => fmt::Debug::fmt(frame, fmt),
+            Reset(ref frame) => fmt::Debug::fmt(frame, fmt),
+        }
+    }
+}
+
+/// Errors that can occur during parsing an HTTP/2 frame.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Error {
+    /// A length value other than 8 was set on a PING message.
+    BadFrameSize,
+
+    /// The padding length was larger than the frame-header-specified
+    /// length of the payload.
+    TooMuchPadding,
+
+    /// An invalid setting value was provided
+    InvalidSettingValue,
+
+    /// An invalid window update value
+    InvalidWindowUpdateValue,
+
+    /// The payload length specified by the frame header was not the
+    /// value necessary for the specific frame type.
+    InvalidPayloadLength,
+
+    /// Received a payload with an ACK settings frame
+    InvalidPayloadAckSettings,
+
+    /// An invalid stream identifier was provided.
+    ///
+    /// This is returned if a SETTINGS or PING frame is received with a stream
+    /// identifier other than zero.
+    InvalidStreamId,
+
+    /// A request or response is malformed.
+    MalformedMessage,
+
+    /// An invalid stream dependency ID was provided
+    ///
+    /// This is returned if a HEADERS or PRIORITY frame is received with an
+    /// invalid stream identifier.
+    InvalidDependencyId,
+
+    /// Failed to perform HPACK decoding
+    Hpack(hpack::DecoderError),
+}

vendor/h2/src/frame/ping.rs

@@ -0,0 +1,102 @@
+use crate::frame::{Error, Frame, Head, Kind, StreamId};
+use bytes::BufMut;
+
+const ACK_FLAG: u8 = 0x1;
+
+pub type Payload = [u8; 8];
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Ping {
+    ack: bool,
+    payload: Payload,
+}
+
+// This was just 8 randomly generated bytes. We use something besides just
+// zeroes to distinguish this specific PING from any other.
+const SHUTDOWN_PAYLOAD: Payload = [0x0b, 0x7b, 0xa2, 0xf0, 0x8b, 0x9b, 0xfe, 0x54];
+const USER_PAYLOAD: Payload = [0x3b, 0x7c, 0xdb, 0x7a, 0x0b, 0x87, 0x16, 0xb4];
+
+impl Ping {
+    #[cfg(feature = "unstable")]
+    pub const SHUTDOWN: Payload = SHUTDOWN_PAYLOAD;
+
+    #[cfg(not(feature = "unstable"))]
+    pub(crate) const SHUTDOWN: Payload = SHUTDOWN_PAYLOAD;
+
+    #[cfg(feature = "unstable")]
+    pub const USER: Payload = USER_PAYLOAD;
+
+    #[cfg(not(feature = "unstable"))]
+    pub(crate) const USER: Payload = USER_PAYLOAD;
+
+    pub fn new(payload: Payload) -> Ping {
+        Ping {
+            ack: false,
+            payload,
+        }
+    }
+
+    pub fn pong(payload: Payload) -> Ping {
+        Ping { ack: true, payload }
+    }
+
+    pub fn is_ack(&self) -> bool {
+        self.ack
+    }
+
+    pub fn payload(&self) -> &Payload {
+        &self.payload
+    }
+
+    pub fn into_payload(self) -> Payload {
+        self.payload
+    }
+
+    /// Builds a `Ping` frame from a raw frame.
+    pub fn load(head: Head, bytes: &[u8]) -> Result<Ping, Error> {
+        debug_assert_eq!(head.kind(), crate::frame::Kind::Ping);
+
+        // PING frames are not associated with any individual stream. If a PING
+        // frame is received with a stream identifier field value other than
+        // 0x0, the recipient MUST respond with a connection error
+        // (Section 5.4.1) of type PROTOCOL_ERROR.
+        if !head.stream_id().is_zero() {
+            return Err(Error::InvalidStreamId);
+        }
+
+        // In addition to the frame header, PING frames MUST contain 8 octets of opaque
+        // data in the payload.
+        if bytes.len() != 8 {
+            return Err(Error::BadFrameSize);
+        }
+
+        let mut payload = [0; 8];
+        payload.copy_from_slice(bytes);
+
+        // The PING frame defines the following flags:
+        //
+        // ACK (0x1): When set, bit 0 indicates that this PING frame is a PING
+        //    response. An endpoint MUST set this flag in PING responses. An
+        //    endpoint MUST NOT respond to PING frames containing this flag.
+        let ack = head.flag() & ACK_FLAG != 0;
+
+        Ok(Ping { ack, payload })
+    }
+
+    pub fn encode<B: BufMut>(&self, dst: &mut B) {
+        let sz = self.payload.len();
+        tracing::trace!("encoding PING; ack={} len={}", self.ack, sz);
+
+        let flags = if self.ack { ACK_FLAG } else { 0 };
+        let head = Head::new(Kind::Ping, flags, StreamId::zero());
+
+        head.encode(sz, dst);
+        dst.put_slice(&self.payload);
+    }
+}
+
+impl<T> From<Ping> for Frame<T> {
+    fn from(src: Ping) -> Frame<T> {
+        Frame::Ping(src)
+    }
+}

vendor/h2/src/frame/priority.rs

@@ -0,0 +1,72 @@
+use crate::frame::*;
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Priority {
+    stream_id: StreamId,
+    dependency: StreamDependency,
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct StreamDependency {
+    /// The ID of the stream dependency target
+    dependency_id: StreamId,
+
+    /// The weight for the stream. The value exposed (and set) here is always in
+    /// the range [0, 255], instead of [1, 256] (as defined in section 5.3.2.)
+    /// so that the value fits into a `u8`.
+    weight: u8,
+
+    /// True if the stream dependency is exclusive.
+    is_exclusive: bool,
+}
+
+impl Priority {
+    pub fn load(head: Head, payload: &[u8]) -> Result<Self, Error> {
+        let dependency = StreamDependency::load(payload)?;
+
+        if dependency.dependency_id() == head.stream_id() {
+            return Err(Error::InvalidDependencyId);
+        }
+
+        Ok(Priority {
+            stream_id: head.stream_id(),
+            dependency,
+        })
+    }
+}
+
+impl<B> From<Priority> for Frame<B> {
+    fn from(src: Priority) -> Self {
+        Frame::Priority(src)
+    }
+}
+
+// ===== impl StreamDependency =====
+
+impl StreamDependency {
+    pub fn new(dependency_id: StreamId, weight: u8, is_exclusive: bool) -> Self {
+        StreamDependency {
+            dependency_id,
+            weight,
+            is_exclusive,
+        }
+    }
+
+    pub fn load(src: &[u8]) -> Result<Self, Error> {
+        if src.len() != 5 {
+            return Err(Error::InvalidPayloadLength);
+        }
+
+        // Parse the stream ID and exclusive flag
+        let (dependency_id, is_exclusive) = StreamId::parse(&src[..4]);
+
+        // Read the weight
+        let weight = src[4];
+
+        Ok(StreamDependency::new(dependency_id, weight, is_exclusive))
+    }
+
+    pub fn dependency_id(&self) -> StreamId {
+        self.dependency_id
+    }
+}

vendor/h2/src/frame/reason.rs

@@ -0,0 +1,134 @@
+use std::fmt;
+
+/// HTTP/2 error codes.
+///
+/// Error codes are used in `RST_STREAM` and `GOAWAY` frames to convey the
+/// reasons for the stream or connection error. For example,
+/// [`SendStream::send_reset`] takes a `Reason` argument. Also, the `Error` type
+/// may contain a `Reason`.
+///
+/// Error codes share a common code space. Some error codes apply only to
+/// streams, others apply only to connections, and others may apply to either.
+/// See [RFC 7540] for more information.
+///
+/// See [Error Codes in the spec][spec].
+///
+/// [spec]: http://httpwg.org/specs/rfc7540.html#ErrorCodes
+/// [`SendStream::send_reset`]: struct.SendStream.html#method.send_reset
+#[derive(PartialEq, Eq, Clone, Copy)]
+pub struct Reason(u32);
+
+impl Reason {
+    /// The associated condition is not a result of an error.
+    ///
+    /// For example, a GOAWAY might include this code to indicate graceful
+    /// shutdown of a connection.
+    pub const NO_ERROR: Reason = Reason(0);
+    /// The endpoint detected an unspecific protocol error.
+    ///
+    /// This error is for use when a more specific error code is not available.
+    pub const PROTOCOL_ERROR: Reason = Reason(1);
+    /// The endpoint encountered an unexpected internal error.
+    pub const INTERNAL_ERROR: Reason = Reason(2);
+    /// The endpoint detected that its peer violated the flow-control protocol.
+    pub const FLOW_CONTROL_ERROR: Reason = Reason(3);
+    /// The endpoint sent a SETTINGS frame but did not receive a response in
+    /// a timely manner.
+    pub const SETTINGS_TIMEOUT: Reason = Reason(4);
+    /// The endpoint received a frame after a stream was half-closed.
+    pub const STREAM_CLOSED: Reason = Reason(5);
+    /// The endpoint received a frame with an invalid size.
+    pub const FRAME_SIZE_ERROR: Reason = Reason(6);
+    /// The endpoint refused the stream prior to performing any application
+    /// processing.
+    pub const REFUSED_STREAM: Reason = Reason(7);
+    /// Used by the endpoint to indicate that the stream is no longer needed.
+    pub const CANCEL: Reason = Reason(8);
+    /// The endpoint is unable to maintain the header compression context for
+    /// the connection.
+    pub const COMPRESSION_ERROR: Reason = Reason(9);
+    /// The connection established in response to a CONNECT request was reset
+    /// or abnormally closed.
+    pub const CONNECT_ERROR: Reason = Reason(10);
+    /// The endpoint detected that its peer is exhibiting a behavior that might
+    /// be generating excessive load.
+    pub const ENHANCE_YOUR_CALM: Reason = Reason(11);
+    /// The underlying transport has properties that do not meet minimum
+    /// security requirements.
+    pub const INADEQUATE_SECURITY: Reason = Reason(12);
+    /// The endpoint requires that HTTP/1.1 be used instead of HTTP/2.
+    pub const HTTP_1_1_REQUIRED: Reason = Reason(13);
+
+    /// Get a string description of the error code.
+    pub fn description(&self) -> &str {
+        match self.0 {
+            0 => "not a result of an error",
+            1 => "unspecific protocol error detected",
+            2 => "unexpected internal error encountered",
+            3 => "flow-control protocol violated",
+            4 => "settings ACK not received in timely manner",
+            5 => "received frame when stream half-closed",
+            6 => "frame with invalid size",
+            7 => "refused stream before processing any application logic",
+            8 => "stream no longer needed",
+            9 => "unable to maintain the header compression context",
+            10 => {
+                "connection established in response to a CONNECT request was reset or abnormally \
+                 closed"
+            }
+            11 => "detected excessive load generating behavior",
+            12 => "security properties do not meet minimum requirements",
+            13 => "endpoint requires HTTP/1.1",
+            _ => "unknown reason",
+        }
+    }
+}
+
+impl From<u32> for Reason {
+    fn from(src: u32) -> Reason {
+        Reason(src)
+    }
+}
+
+impl From<Reason> for u32 {
+    fn from(src: Reason) -> u32 {
+        src.0
+    }
+}
+
+impl fmt::Debug for Reason {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let name = match self.0 {
+            0 => "NO_ERROR",
+            1 => "PROTOCOL_ERROR",
+            2 => "INTERNAL_ERROR",
+            3 => "FLOW_CONTROL_ERROR",
+            4 => "SETTINGS_TIMEOUT",
+            5 => "STREAM_CLOSED",
+            6 => "FRAME_SIZE_ERROR",
+            7 => "REFUSED_STREAM",
+            8 => "CANCEL",
+            9 => "COMPRESSION_ERROR",
+            10 => "CONNECT_ERROR",
+            11 => "ENHANCE_YOUR_CALM",
+            12 => "INADEQUATE_SECURITY",
+            13 => "HTTP_1_1_REQUIRED",
+            other => return f.debug_tuple("Reason").field(&Hex(other)).finish(),
+        };
+        f.write_str(name)
+    }
+}
+
+struct Hex(u32);
+
+impl fmt::Debug for Hex {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::LowerHex::fmt(&self.0, f)
+    }
+}
+
+impl fmt::Display for Reason {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{}", self.description())
+    }
+}

vendor/h2/src/frame/reset.rs

@@ -0,0 +1,56 @@
+use crate::frame::{self, Error, Head, Kind, Reason, StreamId};
+
+use bytes::BufMut;
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub struct Reset {
+    stream_id: StreamId,
+    error_code: Reason,
+}
+
+impl Reset {
+    pub fn new(stream_id: StreamId, error: Reason) -> Reset {
+        Reset {
+            stream_id,
+            error_code: error,
+        }
+    }
+
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    pub fn reason(&self) -> Reason {
+        self.error_code
+    }
+
+    pub fn load(head: Head, payload: &[u8]) -> Result<Reset, Error> {
+        if payload.len() != 4 {
+            return Err(Error::InvalidPayloadLength);
+        }
+
+        let error_code = unpack_octets_4!(payload, 0, u32);
+
+        Ok(Reset {
+            stream_id: head.stream_id(),
+            error_code: error_code.into(),
+        })
+    }
+
+    pub fn encode<B: BufMut>(&self, dst: &mut B) {
+        tracing::trace!(
+            "encoding RESET; id={:?} code={:?}",
+            self.stream_id,
+            self.error_code
+        );
+        let head = Head::new(Kind::Reset, 0, self.stream_id);
+        head.encode(4, dst);
+        dst.put_u32(self.error_code.into());
+    }
+}
+
+impl<B> From<Reset> for frame::Frame<B> {
+    fn from(src: Reset) -> Self {
+        frame::Frame::Reset(src)
+    }
+}

vendor/h2/src/frame/settings.rs

@@ -0,0 +1,389 @@
+use std::fmt;
+
+use crate::frame::{util, Error, Frame, FrameSize, Head, Kind, StreamId};
+use bytes::{BufMut, BytesMut};
+
+#[derive(Clone, Default, Eq, PartialEq)]
+pub struct Settings {
+    flags: SettingsFlags,
+    // Fields
+    header_table_size: Option<u32>,
+    enable_push: Option<u32>,
+    max_concurrent_streams: Option<u32>,
+    initial_window_size: Option<u32>,
+    max_frame_size: Option<u32>,
+    max_header_list_size: Option<u32>,
+    enable_connect_protocol: Option<u32>,
+}
+
+/// An enum that lists all valid settings that can be sent in a SETTINGS
+/// frame.
+///
+/// Each setting has a value that is a 32 bit unsigned integer (6.5.1.).
+#[derive(Debug)]
+pub enum Setting {
+    HeaderTableSize(u32),
+    EnablePush(u32),
+    MaxConcurrentStreams(u32),
+    InitialWindowSize(u32),
+    MaxFrameSize(u32),
+    MaxHeaderListSize(u32),
+    EnableConnectProtocol(u32),
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Default)]
+pub struct SettingsFlags(u8);
+
+const ACK: u8 = 0x1;
+const ALL: u8 = ACK;
+
+/// The default value of SETTINGS_HEADER_TABLE_SIZE
+pub const DEFAULT_SETTINGS_HEADER_TABLE_SIZE: usize = 4_096;
+
+/// The default value of SETTINGS_INITIAL_WINDOW_SIZE
+pub const DEFAULT_INITIAL_WINDOW_SIZE: u32 = 65_535;
+
+/// The default value of MAX_FRAME_SIZE
+pub const DEFAULT_MAX_FRAME_SIZE: FrameSize = 16_384;
+
+/// INITIAL_WINDOW_SIZE upper bound
+pub const MAX_INITIAL_WINDOW_SIZE: usize = (1 << 31) - 1;
+
+/// MAX_FRAME_SIZE upper bound
+pub const MAX_MAX_FRAME_SIZE: FrameSize = (1 << 24) - 1;
+
+// ===== impl Settings =====
+
+impl Settings {
+    pub fn ack() -> Settings {
+        Settings {
+            flags: SettingsFlags::ack(),
+            ..Settings::default()
+        }
+    }
+
+    pub fn is_ack(&self) -> bool {
+        self.flags.is_ack()
+    }
+
+    pub fn initial_window_size(&self) -> Option<u32> {
+        self.initial_window_size
+    }
+
+    pub fn set_initial_window_size(&mut self, size: Option<u32>) {
+        self.initial_window_size = size;
+    }
+
+    pub fn max_concurrent_streams(&self) -> Option<u32> {
+        self.max_concurrent_streams
+    }
+
+    pub fn set_max_concurrent_streams(&mut self, max: Option<u32>) {
+        self.max_concurrent_streams = max;
+    }
+
+    pub fn max_frame_size(&self) -> Option<u32> {
+        self.max_frame_size
+    }
+
+    pub fn set_max_frame_size(&mut self, size: Option<u32>) {
+        if let Some(val) = size {
+            assert!(DEFAULT_MAX_FRAME_SIZE <= val && val <= MAX_MAX_FRAME_SIZE);
+        }
+        self.max_frame_size = size;
+    }
+
+    pub fn max_header_list_size(&self) -> Option<u32> {
+        self.max_header_list_size
+    }
+
+    pub fn set_max_header_list_size(&mut self, size: Option<u32>) {
+        self.max_header_list_size = size;
+    }
+
+    pub fn is_push_enabled(&self) -> Option<bool> {
+        self.enable_push.map(|val| val != 0)
+    }
+
+    pub fn set_enable_push(&mut self, enable: bool) {
+        self.enable_push = Some(enable as u32);
+    }
+
+    pub fn is_extended_connect_protocol_enabled(&self) -> Option<bool> {
+        self.enable_connect_protocol.map(|val| val != 0)
+    }
+
+    pub fn set_enable_connect_protocol(&mut self, val: Option<u32>) {
+        self.enable_connect_protocol = val;
+    }
+
+    pub fn header_table_size(&self) -> Option<u32> {
+        self.header_table_size
+    }
+
+    pub fn set_header_table_size(&mut self, size: Option<u32>) {
+        self.header_table_size = size;
+    }
+
+    pub fn load(head: Head, payload: &[u8]) -> Result<Settings, Error> {
+        use self::Setting::*;
+
+        debug_assert_eq!(head.kind(), crate::frame::Kind::Settings);
+
+        if !head.stream_id().is_zero() {
+            return Err(Error::InvalidStreamId);
+        }
+
+        // Load the flag
+        let flag = SettingsFlags::load(head.flag());
+
+        if flag.is_ack() {
+            // Ensure that the payload is empty
+            if !payload.is_empty() {
+                return Err(Error::InvalidPayloadLength);
+            }
+
+            // Return the ACK frame
+            return Ok(Settings::ack());
+        }
+
+        // Ensure the payload length is correct, each setting is 6 bytes long.
+        if payload.len() % 6 != 0 {
+            tracing::debug!("invalid settings payload length; len={:?}", payload.len());
+            return Err(Error::InvalidPayloadAckSettings);
+        }
+
+        let mut settings = Settings::default();
+        debug_assert!(!settings.flags.is_ack());
+
+        for raw in payload.chunks(6) {
+            match Setting::load(raw) {
+                Some(HeaderTableSize(val)) => {
+                    settings.header_table_size = Some(val);
+                }
+                Some(EnablePush(val)) => match val {
+                    0 | 1 => {
+                        settings.enable_push = Some(val);
+                    }
+                    _ => {
+                        return Err(Error::InvalidSettingValue);
+                    }
+                },
+                Some(MaxConcurrentStreams(val)) => {
+                    settings.max_concurrent_streams = Some(val);
+                }
+                Some(InitialWindowSize(val)) => {
+                    if val as usize > MAX_INITIAL_WINDOW_SIZE {
+                        return Err(Error::InvalidSettingValue);
+                    } else {
+                        settings.initial_window_size = Some(val);
+                    }
+                }
+                Some(MaxFrameSize(val)) => {
+                    if DEFAULT_MAX_FRAME_SIZE <= val && val <= MAX_MAX_FRAME_SIZE {
+                        settings.max_frame_size = Some(val);
+                    } else {
+                        return Err(Error::InvalidSettingValue);
+                    }
+                }
+                Some(MaxHeaderListSize(val)) => {
+                    settings.max_header_list_size = Some(val);
+                }
+                Some(EnableConnectProtocol(val)) => match val {
+                    0 | 1 => {
+                        settings.enable_connect_protocol = Some(val);
+                    }
+                    _ => {
+                        return Err(Error::InvalidSettingValue);
+                    }
+                },
+                None => {}
+            }
+        }
+
+        Ok(settings)
+    }
+
+    fn payload_len(&self) -> usize {
+        let mut len = 0;
+        self.for_each(|_| len += 6);
+        len
+    }
+
+    pub fn encode(&self, dst: &mut BytesMut) {
+        // Create & encode an appropriate frame head
+        let head = Head::new(Kind::Settings, self.flags.into(), StreamId::zero());
+        let payload_len = self.payload_len();
+
+        tracing::trace!("encoding SETTINGS; len={}", payload_len);
+
+        head.encode(payload_len, dst);
+
+        // Encode the settings
+        self.for_each(|setting| {
+            tracing::trace!("encoding setting; val={:?}", setting);
+            setting.encode(dst)
+        });
+    }
+
+    fn for_each<F: FnMut(Setting)>(&self, mut f: F) {
+        use self::Setting::*;
+
+        if let Some(v) = self.header_table_size {
+            f(HeaderTableSize(v));
+        }
+
+        if let Some(v) = self.enable_push {
+            f(EnablePush(v));
+        }
+
+        if let Some(v) = self.max_concurrent_streams {
+            f(MaxConcurrentStreams(v));
+        }
+
+        if let Some(v) = self.initial_window_size {
+            f(InitialWindowSize(v));
+        }
+
+        if let Some(v) = self.max_frame_size {
+            f(MaxFrameSize(v));
+        }
+
+        if let Some(v) = self.max_header_list_size {
+            f(MaxHeaderListSize(v));
+        }
+
+        if let Some(v) = self.enable_connect_protocol {
+            f(EnableConnectProtocol(v));
+        }
+    }
+}
+
+impl<T> From<Settings> for Frame<T> {
+    fn from(src: Settings) -> Frame<T> {
+        Frame::Settings(src)
+    }
+}
+
+impl fmt::Debug for Settings {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut builder = f.debug_struct("Settings");
+        builder.field("flags", &self.flags);
+
+        self.for_each(|setting| match setting {
+            Setting::EnablePush(v) => {
+                builder.field("enable_push", &v);
+            }
+            Setting::HeaderTableSize(v) => {
+                builder.field("header_table_size", &v);
+            }
+            Setting::InitialWindowSize(v) => {
+                builder.field("initial_window_size", &v);
+            }
+            Setting::MaxConcurrentStreams(v) => {
+                builder.field("max_concurrent_streams", &v);
+            }
+            Setting::MaxFrameSize(v) => {
+                builder.field("max_frame_size", &v);
+            }
+            Setting::MaxHeaderListSize(v) => {
+                builder.field("max_header_list_size", &v);
+            }
+            Setting::EnableConnectProtocol(v) => {
+                builder.field("enable_connect_protocol", &v);
+            }
+        });
+
+        builder.finish()
+    }
+}
+
+// ===== impl Setting =====
+
+impl Setting {
+    /// Creates a new `Setting` with the correct variant corresponding to the
+    /// given setting id, based on the settings IDs defined in section
+    /// 6.5.2.
+    pub fn from_id(id: u16, val: u32) -> Option<Setting> {
+        use self::Setting::*;
+
+        match id {
+            1 => Some(HeaderTableSize(val)),
+            2 => Some(EnablePush(val)),
+            3 => Some(MaxConcurrentStreams(val)),
+            4 => Some(InitialWindowSize(val)),
+            5 => Some(MaxFrameSize(val)),
+            6 => Some(MaxHeaderListSize(val)),
+            8 => Some(EnableConnectProtocol(val)),
+            _ => None,
+        }
+    }
+
+    /// Creates a new `Setting` by parsing the given buffer of 6 bytes, which
+    /// contains the raw byte representation of the setting, according to the
+    /// "SETTINGS format" defined in section 6.5.1.
+    ///
+    /// The `raw` parameter should have length at least 6 bytes, since the
+    /// length of the raw setting is exactly 6 bytes.
+    ///
+    /// # Panics
+    ///
+    /// If given a buffer shorter than 6 bytes, the function will panic.
+    fn load(raw: &[u8]) -> Option<Setting> {
+        let id: u16 = (u16::from(raw[0]) << 8) | u16::from(raw[1]);
+        let val: u32 = unpack_octets_4!(raw, 2, u32);
+
+        Setting::from_id(id, val)
+    }
+
+    fn encode(&self, dst: &mut BytesMut) {
+        use self::Setting::*;
+
+        let (kind, val) = match *self {
+            HeaderTableSize(v) => (1, v),
+            EnablePush(v) => (2, v),
+            MaxConcurrentStreams(v) => (3, v),
+            InitialWindowSize(v) => (4, v),
+            MaxFrameSize(v) => (5, v),
+            MaxHeaderListSize(v) => (6, v),
+            EnableConnectProtocol(v) => (8, v),
+        };
+
+        dst.put_u16(kind);
+        dst.put_u32(val);
+    }
+}
+
+// ===== impl SettingsFlags =====
+
+impl SettingsFlags {
+    pub fn empty() -> SettingsFlags {
+        SettingsFlags(0)
+    }
+
+    pub fn load(bits: u8) -> SettingsFlags {
+        SettingsFlags(bits & ALL)
+    }
+
+    pub fn ack() -> SettingsFlags {
+        SettingsFlags(ACK)
+    }
+
+    pub fn is_ack(&self) -> bool {
+        self.0 & ACK == ACK
+    }
+}
+
+impl From<SettingsFlags> for u8 {
+    fn from(src: SettingsFlags) -> u8 {
+        src.0
+    }
+}
+
+impl fmt::Debug for SettingsFlags {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        util::debug_flags(f, self.0)
+            .flag_if(self.is_ack(), "ACK")
+            .finish()
+    }
+}

vendor/h2/src/frame/stream_id.rs

@@ -0,0 +1,94 @@
+/// A stream identifier, as described in [Section 5.1.1] of RFC 7540.
+///
+/// Streams are identified with an unsigned 31-bit integer. Streams
+/// initiated by a client MUST use odd-numbered stream identifiers; those
+/// initiated by the server MUST use even-numbered stream identifiers.  A
+/// stream identifier of zero (0x0) is used for connection control
+/// messages; the stream identifier of zero cannot be used to establish a
+/// new stream.
+///
+/// [Section 5.1.1]: https://tools.ietf.org/html/rfc7540#section-5.1.1
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct StreamId(u32);
+
+#[derive(Debug, Copy, Clone)]
+pub struct StreamIdOverflow;
+
+const STREAM_ID_MASK: u32 = 1 << 31;
+
+impl StreamId {
+    /// Stream ID 0.
+    pub const ZERO: StreamId = StreamId(0);
+
+    /// The maximum allowed stream ID.
+    pub const MAX: StreamId = StreamId(u32::MAX >> 1);
+
+    /// Parse the stream ID
+    #[inline]
+    pub fn parse(buf: &[u8]) -> (StreamId, bool) {
+        let mut ubuf = [0; 4];
+        ubuf.copy_from_slice(&buf[0..4]);
+        let unpacked = u32::from_be_bytes(ubuf);
+        let flag = unpacked & STREAM_ID_MASK == STREAM_ID_MASK;
+
+        // Now clear the most significant bit, as that is reserved and MUST be
+        // ignored when received.
+        (StreamId(unpacked & !STREAM_ID_MASK), flag)
+    }
+
+    /// Returns true if this stream ID corresponds to a stream that
+    /// was initiated by the client.
+    pub fn is_client_initiated(&self) -> bool {
+        let id = self.0;
+        id != 0 && id % 2 == 1
+    }
+
+    /// Returns true if this stream ID corresponds to a stream that
+    /// was initiated by the server.
+    pub fn is_server_initiated(&self) -> bool {
+        let id = self.0;
+        id != 0 && id % 2 == 0
+    }
+
+    /// Return a new `StreamId` for stream 0.
+    #[inline]
+    pub fn zero() -> StreamId {
+        StreamId::ZERO
+    }
+
+    /// Returns true if this stream ID is zero.
+    pub fn is_zero(&self) -> bool {
+        self.0 == 0
+    }
+
+    /// Returns the next stream ID initiated by the same peer as this stream
+    /// ID, or an error if incrementing this stream ID would overflow the
+    /// maximum.
+    pub fn next_id(&self) -> Result<StreamId, StreamIdOverflow> {
+        let next = self.0 + 2;
+        if next > StreamId::MAX.0 {
+            Err(StreamIdOverflow)
+        } else {
+            Ok(StreamId(next))
+        }
+    }
+}
+
+impl From<u32> for StreamId {
+    fn from(src: u32) -> Self {
+        assert_eq!(src & STREAM_ID_MASK, 0, "invalid stream ID -- MSB is set");
+        StreamId(src)
+    }
+}
+
+impl From<StreamId> for u32 {
+    fn from(src: StreamId) -> Self {
+        src.0
+    }
+}
+
+impl PartialEq<u32> for StreamId {
+    fn eq(&self, other: &u32) -> bool {
+        self.0 == *other
+    }
+}

vendor/h2/src/frame/util.rs

@@ -0,0 +1,79 @@
+use std::fmt;
+
+use super::Error;
+use bytes::{Buf, Bytes};
+
+/// Strip padding from the given payload.
+///
+/// It is assumed that the frame had the padded flag set. This means that the
+/// first byte is the length of the padding with that many
+/// 0 bytes expected to follow the actual payload.
+///
+/// # Returns
+///
+/// A slice of the given payload where the actual one is found and the length
+/// of the padding.
+///
+/// If the padded payload is invalid (e.g. the length of the padding is equal
+/// to the total length), returns `None`.
+pub fn strip_padding(payload: &mut Bytes) -> Result<u8, Error> {
+    let payload_len = payload.len();
+    if payload_len == 0 {
+        // If this is the case, the frame is invalid as no padding length can be
+        // extracted, even though the frame should be padded.
+        return Err(Error::TooMuchPadding);
+    }
+
+    let pad_len = payload[0] as usize;
+
+    if pad_len >= payload_len {
+        // This is invalid: the padding length MUST be less than the
+        // total frame size.
+        return Err(Error::TooMuchPadding);
+    }
+
+    payload.advance(1);
+    payload.truncate(payload_len - pad_len - 1);
+
+    Ok(pad_len as u8)
+}
+
+pub(super) fn debug_flags<'a, 'f: 'a>(
+    fmt: &'a mut fmt::Formatter<'f>,
+    bits: u8,
+) -> DebugFlags<'a, 'f> {
+    let result = write!(fmt, "({:#x}", bits);
+    DebugFlags {
+        fmt,
+        result,
+        started: false,
+    }
+}
+
+pub(super) struct DebugFlags<'a, 'f: 'a> {
+    fmt: &'a mut fmt::Formatter<'f>,
+    result: fmt::Result,
+    started: bool,
+}
+
+impl<'a, 'f: 'a> DebugFlags<'a, 'f> {
+    pub(super) fn flag_if(&mut self, enabled: bool, name: &str) -> &mut Self {
+        if enabled {
+            self.result = self.result.and_then(|()| {
+                let prefix = if self.started {
+                    " | "
+                } else {
+                    self.started = true;
+                    ": "
+                };
+
+                write!(self.fmt, "{}{}", prefix, name)
+            });
+        }
+        self
+    }
+
+    pub(super) fn finish(&mut self) -> fmt::Result {
+        self.result.and_then(|()| write!(self.fmt, ")"))
+    }
+}

vendor/h2/src/frame/window_update.rs

@@ -0,0 +1,62 @@
+use crate::frame::{self, Error, Head, Kind, StreamId};
+
+use bytes::BufMut;
+
+const SIZE_INCREMENT_MASK: u32 = 1 << 31;
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct WindowUpdate {
+    stream_id: StreamId,
+    size_increment: u32,
+}
+
+impl WindowUpdate {
+    pub fn new(stream_id: StreamId, size_increment: u32) -> WindowUpdate {
+        WindowUpdate {
+            stream_id,
+            size_increment,
+        }
+    }
+
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    pub fn size_increment(&self) -> u32 {
+        self.size_increment
+    }
+
+    /// Builds a `WindowUpdate` frame from a raw frame.
+    pub fn load(head: Head, payload: &[u8]) -> Result<WindowUpdate, Error> {
+        debug_assert_eq!(head.kind(), crate::frame::Kind::WindowUpdate);
+        if payload.len() != 4 {
+            return Err(Error::BadFrameSize);
+        }
+
+        // Clear the most significant bit, as that is reserved and MUST be ignored
+        // when received.
+        let size_increment = unpack_octets_4!(payload, 0, u32) & !SIZE_INCREMENT_MASK;
+
+        if size_increment == 0 {
+            return Err(Error::InvalidWindowUpdateValue);
+        }
+
+        Ok(WindowUpdate {
+            stream_id: head.stream_id(),
+            size_increment,
+        })
+    }
+
+    pub fn encode<B: BufMut>(&self, dst: &mut B) {
+        tracing::trace!("encoding WINDOW_UPDATE; id={:?}", self.stream_id);
+        let head = Head::new(Kind::WindowUpdate, 0, self.stream_id);
+        head.encode(4, dst);
+        dst.put_u32(self.size_increment);
+    }
+}
+
+impl<B> From<WindowUpdate> for frame::Frame<B> {
+    fn from(src: WindowUpdate) -> Self {
+        frame::Frame::WindowUpdate(src)
+    }
+}

vendor/h2/src/fuzz_bridge.rs

@@ -0,0 +1,28 @@
+#[cfg(fuzzing)]
+pub mod fuzz_logic {
+    use crate::hpack;
+    use bytes::BytesMut;
+    use http::header::HeaderName;
+    use std::io::Cursor;
+
+    pub fn fuzz_hpack(data_: &[u8]) {
+        let mut decoder_ = hpack::Decoder::new(0);
+        let mut buf = BytesMut::new();
+        buf.extend(data_);
+        let _dec_res = decoder_.decode(&mut Cursor::new(&mut buf), |_h| {});
+
+        if let Ok(s) = std::str::from_utf8(data_) {
+            if let Ok(h) = http::Method::from_bytes(s.as_bytes()) {
+                let m_ = hpack::Header::Method(h);
+                let mut encoder = hpack::Encoder::new(0, 0);
+                let _res = encode(&mut encoder, vec![m_]);
+            }
+        }
+    }
+
+    fn encode(e: &mut hpack::Encoder, hdrs: Vec<hpack::Header<Option<HeaderName>>>) -> BytesMut {
+        let mut dst = BytesMut::with_capacity(1024);
+        e.encode(&mut hdrs.into_iter(), &mut dst);
+        dst
+    }
+}

vendor/h2/src/hpack/decoder.rs

@@ -0,0 +1,936 @@
+use super::{header::BytesStr, huffman, Header};
+use crate::frame;
+
+use bytes::{Buf, Bytes, BytesMut};
+use http::header;
+use http::method::{self, Method};
+use http::status::{self, StatusCode};
+
+use std::cmp;
+use std::collections::VecDeque;
+use std::io::Cursor;
+use std::str::Utf8Error;
+
+/// Decodes headers using HPACK
+#[derive(Debug)]
+pub struct Decoder {
+    // Protocol indicated that the max table size will update
+    max_size_update: Option<usize>,
+    last_max_update: usize,
+    table: Table,
+    buffer: BytesMut,
+}
+
+/// Represents all errors that can be encountered while performing the decoding
+/// of an HPACK header set.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum DecoderError {
+    InvalidRepresentation,
+    InvalidIntegerPrefix,
+    InvalidTableIndex,
+    InvalidHuffmanCode,
+    InvalidUtf8,
+    InvalidStatusCode,
+    InvalidPseudoheader,
+    InvalidMaxDynamicSize,
+    IntegerOverflow,
+    NeedMore(NeedMore),
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum NeedMore {
+    UnexpectedEndOfStream,
+    IntegerUnderflow,
+    StringUnderflow,
+}
+
+enum Representation {
+    /// Indexed header field representation
+    ///
+    /// An indexed header field representation identifies an entry in either the
+    /// static table or the dynamic table (see Section 2.3).
+    ///
+    /// # Header encoding
+    ///
+    /// ```text
+    ///   0   1   2   3   4   5   6   7
+    /// +---+---+---+---+---+---+---+---+
+    /// | 1 |        Index (7+)         |
+    /// +---+---------------------------+
+    /// ```
+    Indexed,
+
+    /// Literal Header Field with Incremental Indexing
+    ///
+    /// A literal header field with incremental indexing representation results
+    /// in appending a header field to the decoded header list and inserting it
+    /// as a new entry into the dynamic table.
+    ///
+    /// # Header encoding
+    ///
+    /// ```text
+    ///   0   1   2   3   4   5   6   7
+    /// +---+---+---+---+---+---+---+---+
+    /// | 0 | 1 |      Index (6+)       |
+    /// +---+---+-----------------------+
+    /// | H |     Value Length (7+)     |
+    /// +---+---------------------------+
+    /// | Value String (Length octets)  |
+    /// +-------------------------------+
+    /// ```
+    LiteralWithIndexing,
+
+    /// Literal Header Field without Indexing
+    ///
+    /// A literal header field without indexing representation results in
+    /// appending a header field to the decoded header list without altering the
+    /// dynamic table.
+    ///
+    /// # Header encoding
+    ///
+    /// ```text
+    ///   0   1   2   3   4   5   6   7
+    /// +---+---+---+---+---+---+---+---+
+    /// | 0 | 0 | 0 | 0 |  Index (4+)   |
+    /// +---+---+-----------------------+
+    /// | H |     Value Length (7+)     |
+    /// +---+---------------------------+
+    /// | Value String (Length octets)  |
+    /// +-------------------------------+
+    /// ```
+    LiteralWithoutIndexing,
+
+    /// Literal Header Field Never Indexed
+    ///
+    /// A literal header field never-indexed representation results in appending
+    /// a header field to the decoded header list without altering the dynamic
+    /// table. Intermediaries MUST use the same representation for encoding this
+    /// header field.
+    ///
+    /// ```text
+    ///   0   1   2   3   4   5   6   7
+    /// +---+---+---+---+---+---+---+---+
+    /// | 0 | 0 | 0 | 1 |  Index (4+)   |
+    /// +---+---+-----------------------+
+    /// | H |     Value Length (7+)     |
+    /// +---+---------------------------+
+    /// | Value String (Length octets)  |
+    /// +-------------------------------+
+    /// ```
+    LiteralNeverIndexed,
+
+    /// Dynamic Table Size Update
+    ///
+    /// A dynamic table size update signals a change to the size of the dynamic
+    /// table.
+    ///
+    /// # Header encoding
+    ///
+    /// ```text
+    ///   0   1   2   3   4   5   6   7
+    /// +---+---+---+---+---+---+---+---+
+    /// | 0 | 0 | 1 |   Max size (5+)   |
+    /// +---+---------------------------+
+    /// ```
+    SizeUpdate,
+}
+
+#[derive(Debug)]
+struct Table {
+    entries: VecDeque<Header>,
+    size: usize,
+    max_size: usize,
+}
+
+struct StringMarker {
+    offset: usize,
+    len: usize,
+    string: Option<Bytes>,
+}
+
+// ===== impl Decoder =====
+
+impl Decoder {
+    /// Creates a new `Decoder` with all settings set to default values.
+    pub fn new(size: usize) -> Decoder {
+        Decoder {
+            max_size_update: None,
+            last_max_update: size,
+            table: Table::new(size),
+            buffer: BytesMut::with_capacity(4096),
+        }
+    }
+
+    /// Queues a potential size update
+    #[allow(dead_code)]
+    pub fn queue_size_update(&mut self, size: usize) {
+        let size = match self.max_size_update {
+            Some(v) => cmp::max(v, size),
+            None => size,
+        };
+
+        self.max_size_update = Some(size);
+    }
+
+    /// Decodes the headers found in the given buffer.
+    pub fn decode<F>(
+        &mut self,
+        src: &mut Cursor<&mut BytesMut>,
+        mut f: F,
+    ) -> Result<(), DecoderError>
+    where
+        F: FnMut(Header),
+    {
+        use self::Representation::*;
+
+        let mut can_resize = true;
+
+        if let Some(size) = self.max_size_update.take() {
+            self.last_max_update = size;
+        }
+
+        let span = tracing::trace_span!("hpack::decode");
+        let _e = span.enter();
+
+        tracing::trace!("decode");
+
+        while let Some(ty) = peek_u8(src) {
+            // At this point we are always at the beginning of the next block
+            // within the HPACK data. The type of the block can always be
+            // determined from the first byte.
+            match Representation::load(ty)? {
+                Indexed => {
+                    tracing::trace!(rem = src.remaining(), kind = %"Indexed");
+                    can_resize = false;
+                    let entry = self.decode_indexed(src)?;
+                    consume(src);
+                    f(entry);
+                }
+                LiteralWithIndexing => {
+                    tracing::trace!(rem = src.remaining(), kind = %"LiteralWithIndexing");
+                    can_resize = false;
+                    let entry = self.decode_literal(src, true)?;
+
+                    // Insert the header into the table
+                    self.table.insert(entry.clone());
+                    consume(src);
+
+                    f(entry);
+                }
+                LiteralWithoutIndexing => {
+                    tracing::trace!(rem = src.remaining(), kind = %"LiteralWithoutIndexing");
+                    can_resize = false;
+                    let entry = self.decode_literal(src, false)?;
+                    consume(src);
+                    f(entry);
+                }
+                LiteralNeverIndexed => {
+                    tracing::trace!(rem = src.remaining(), kind = %"LiteralNeverIndexed");
+                    can_resize = false;
+                    let entry = self.decode_literal(src, false)?;
+                    consume(src);
+
+                    // TODO: Track that this should never be indexed
+
+                    f(entry);
+                }
+                SizeUpdate => {
+                    tracing::trace!(rem = src.remaining(), kind = %"SizeUpdate");
+                    if !can_resize {
+                        return Err(DecoderError::InvalidMaxDynamicSize);
+                    }
+
+                    // Handle the dynamic table size update
+                    self.process_size_update(src)?;
+                    consume(src);
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn process_size_update(&mut self, buf: &mut Cursor<&mut BytesMut>) -> Result<(), DecoderError> {
+        let new_size = decode_int(buf, 5)?;
+
+        if new_size > self.last_max_update {
+            return Err(DecoderError::InvalidMaxDynamicSize);
+        }
+
+        tracing::debug!(
+            from = self.table.size(),
+            to = new_size,
+            "Decoder changed max table size"
+        );
+
+        self.table.set_max_size(new_size);
+
+        Ok(())
+    }
+
+    fn decode_indexed(&self, buf: &mut Cursor<&mut BytesMut>) -> Result<Header, DecoderError> {
+        let index = decode_int(buf, 7)?;
+        self.table.get(index)
+    }
+
+    fn decode_literal(
+        &mut self,
+        buf: &mut Cursor<&mut BytesMut>,
+        index: bool,
+    ) -> Result<Header, DecoderError> {
+        let prefix = if index { 6 } else { 4 };
+
+        // Extract the table index for the name, or 0 if not indexed
+        let table_idx = decode_int(buf, prefix)?;
+
+        // First, read the header name
+        if table_idx == 0 {
+            let old_pos = buf.position();
+            let name_marker = self.try_decode_string(buf)?;
+            let value_marker = self.try_decode_string(buf)?;
+            buf.set_position(old_pos);
+            // Read the name as a literal
+            let name = name_marker.consume(buf);
+            let value = value_marker.consume(buf);
+            Header::new(name, value)
+        } else {
+            let e = self.table.get(table_idx)?;
+            let value = self.decode_string(buf)?;
+
+            e.name().into_entry(value)
+        }
+    }
+
+    fn try_decode_string(
+        &mut self,
+        buf: &mut Cursor<&mut BytesMut>,
+    ) -> Result<StringMarker, DecoderError> {
+        let old_pos = buf.position();
+        const HUFF_FLAG: u8 = 0b1000_0000;
+
+        // The first bit in the first byte contains the huffman encoded flag.
+        let huff = match peek_u8(buf) {
+            Some(hdr) => (hdr & HUFF_FLAG) == HUFF_FLAG,
+            None => return Err(DecoderError::NeedMore(NeedMore::UnexpectedEndOfStream)),
+        };
+
+        // Decode the string length using 7 bit prefix
+        let len = decode_int(buf, 7)?;
+
+        if len > buf.remaining() {
+            tracing::trace!(len, remaining = buf.remaining(), "decode_string underflow",);
+            return Err(DecoderError::NeedMore(NeedMore::StringUnderflow));
+        }
+
+        let offset = (buf.position() - old_pos) as usize;
+        if huff {
+            let ret = {
+                let raw = &buf.chunk()[..len];
+                huffman::decode(raw, &mut self.buffer).map(|buf| StringMarker {
+                    offset,
+                    len,
+                    string: Some(BytesMut::freeze(buf)),
+                })
+            };
+
+            buf.advance(len);
+            ret
+        } else {
+            buf.advance(len);
+            Ok(StringMarker {
+                offset,
+                len,
+                string: None,
+            })
+        }
+    }
+
+    fn decode_string(&mut self, buf: &mut Cursor<&mut BytesMut>) -> Result<Bytes, DecoderError> {
+        let old_pos = buf.position();
+        let marker = self.try_decode_string(buf)?;
+        buf.set_position(old_pos);
+        Ok(marker.consume(buf))
+    }
+}
+
+impl Default for Decoder {
+    fn default() -> Decoder {
+        Decoder::new(4096)
+    }
+}
+
+// ===== impl Representation =====
+
+impl Representation {
+    pub fn load(byte: u8) -> Result<Representation, DecoderError> {
+        const INDEXED: u8 = 0b1000_0000;
+        const LITERAL_WITH_INDEXING: u8 = 0b0100_0000;
+        const LITERAL_WITHOUT_INDEXING: u8 = 0b1111_0000;
+        const LITERAL_NEVER_INDEXED: u8 = 0b0001_0000;
+        const SIZE_UPDATE_MASK: u8 = 0b1110_0000;
+        const SIZE_UPDATE: u8 = 0b0010_0000;
+
+        // TODO: What did I even write here?
+
+        if byte & INDEXED == INDEXED {
+            Ok(Representation::Indexed)
+        } else if byte & LITERAL_WITH_INDEXING == LITERAL_WITH_INDEXING {
+            Ok(Representation::LiteralWithIndexing)
+        } else if byte & LITERAL_WITHOUT_INDEXING == 0 {
+            Ok(Representation::LiteralWithoutIndexing)
+        } else if byte & LITERAL_WITHOUT_INDEXING == LITERAL_NEVER_INDEXED {
+            Ok(Representation::LiteralNeverIndexed)
+        } else if byte & SIZE_UPDATE_MASK == SIZE_UPDATE {
+            Ok(Representation::SizeUpdate)
+        } else {
+            Err(DecoderError::InvalidRepresentation)
+        }
+    }
+}
+
+fn decode_int<B: Buf>(buf: &mut B, prefix_size: u8) -> Result<usize, DecoderError> {
+    // The octet limit is chosen such that the maximum allowed *value* can
+    // never overflow an unsigned 32-bit integer. The maximum value of any
+    // integer that can be encoded with 5 octets is ~2^28
+    const MAX_BYTES: usize = 5;
+    const VARINT_MASK: u8 = 0b0111_1111;
+    const VARINT_FLAG: u8 = 0b1000_0000;
+
+    if prefix_size < 1 || prefix_size > 8 {
+        return Err(DecoderError::InvalidIntegerPrefix);
+    }
+
+    if !buf.has_remaining() {
+        return Err(DecoderError::NeedMore(NeedMore::IntegerUnderflow));
+    }
+
+    let mask = if prefix_size == 8 {
+        0xFF
+    } else {
+        (1u8 << prefix_size).wrapping_sub(1)
+    };
+
+    let mut ret = (buf.get_u8() & mask) as usize;
+
+    if ret < mask as usize {
+        // Value fits in the prefix bits
+        return Ok(ret);
+    }
+
+    // The int did not fit in the prefix bits, so continue reading.
+    //
+    // The total number of bytes used to represent the int. The first byte was
+    // the prefix, so start at 1.
+    let mut bytes = 1;
+
+    // The rest of the int is stored as a varint -- 7 bits for the value and 1
+    // bit to indicate if it is the last byte.
+    let mut shift = 0;
+
+    while buf.has_remaining() {
+        let b = buf.get_u8();
+
+        bytes += 1;
+        ret += ((b & VARINT_MASK) as usize) << shift;
+        shift += 7;
+
+        if b & VARINT_FLAG == 0 {
+            return Ok(ret);
+        }
+
+        if bytes == MAX_BYTES {
+            // The spec requires that this situation is an error
+            return Err(DecoderError::IntegerOverflow);
+        }
+    }
+
+    Err(DecoderError::NeedMore(NeedMore::IntegerUnderflow))
+}
+
+fn peek_u8<B: Buf>(buf: &B) -> Option<u8> {
+    if buf.has_remaining() {
+        Some(buf.chunk()[0])
+    } else {
+        None
+    }
+}
+
+fn take(buf: &mut Cursor<&mut BytesMut>, n: usize) -> Bytes {
+    let pos = buf.position() as usize;
+    let mut head = buf.get_mut().split_to(pos + n);
+    buf.set_position(0);
+    head.advance(pos);
+    head.freeze()
+}
+
+impl StringMarker {
+    fn consume(self, buf: &mut Cursor<&mut BytesMut>) -> Bytes {
+        buf.advance(self.offset);
+        match self.string {
+            Some(string) => {
+                buf.advance(self.len);
+                string
+            }
+            None => take(buf, self.len),
+        }
+    }
+}
+
+fn consume(buf: &mut Cursor<&mut BytesMut>) {
+    // remove bytes from the internal BytesMut when they have been successfully
+    // decoded. This is a more permanent cursor position, which will be
+    // used to resume if decoding was only partial.
+    take(buf, 0);
+}
+
+// ===== impl Table =====
+
+impl Table {
+    fn new(max_size: usize) -> Table {
+        Table {
+            entries: VecDeque::new(),
+            size: 0,
+            max_size,
+        }
+    }
+
+    fn size(&self) -> usize {
+        self.size
+    }
+
+    /// Returns the entry located at the given index.
+    ///
+    /// The table is 1-indexed and constructed in such a way that the first
+    /// entries belong to the static table, followed by entries in the dynamic
+    /// table. They are merged into a single index address space, though.
+    ///
+    /// This is according to the [HPACK spec, section 2.3.3.]
+    /// (http://http2.github.io/http2-spec/compression.html#index.address.space)
+    pub fn get(&self, index: usize) -> Result<Header, DecoderError> {
+        if index == 0 {
+            return Err(DecoderError::InvalidTableIndex);
+        }
+
+        if index <= 61 {
+            return Ok(get_static(index));
+        }
+
+        // Convert the index for lookup in the entries structure.
+        match self.entries.get(index - 62) {
+            Some(e) => Ok(e.clone()),
+            None => Err(DecoderError::InvalidTableIndex),
+        }
+    }
+
+    fn insert(&mut self, entry: Header) {
+        let len = entry.len();
+
+        self.reserve(len);
+
+        if self.size + len <= self.max_size {
+            self.size += len;
+
+            // Track the entry
+            self.entries.push_front(entry);
+        }
+    }
+
+    fn set_max_size(&mut self, size: usize) {
+        self.max_size = size;
+        // Make the table size fit within the new constraints.
+        self.consolidate();
+    }
+
+    fn reserve(&mut self, size: usize) {
+        while self.size + size > self.max_size {
+            match self.entries.pop_back() {
+                Some(last) => {
+                    self.size -= last.len();
+                }
+                None => return,
+            }
+        }
+    }
+
+    fn consolidate(&mut self) {
+        while self.size > self.max_size {
+            {
+                let last = match self.entries.back() {
+                    Some(x) => x,
+                    None => {
+                        // Can never happen as the size of the table must reach
+                        // 0 by the time we've exhausted all elements.
+                        panic!("Size of table != 0, but no headers left!");
+                    }
+                };
+
+                self.size -= last.len();
+            }
+
+            self.entries.pop_back();
+        }
+    }
+}
+
+// ===== impl DecoderError =====
+
+impl From<Utf8Error> for DecoderError {
+    fn from(_: Utf8Error) -> DecoderError {
+        // TODO: Better error?
+        DecoderError::InvalidUtf8
+    }
+}
+
+impl From<header::InvalidHeaderValue> for DecoderError {
+    fn from(_: header::InvalidHeaderValue) -> DecoderError {
+        // TODO: Better error?
+        DecoderError::InvalidUtf8
+    }
+}
+
+impl From<header::InvalidHeaderName> for DecoderError {
+    fn from(_: header::InvalidHeaderName) -> DecoderError {
+        // TODO: Better error
+        DecoderError::InvalidUtf8
+    }
+}
+
+impl From<method::InvalidMethod> for DecoderError {
+    fn from(_: method::InvalidMethod) -> DecoderError {
+        // TODO: Better error
+        DecoderError::InvalidUtf8
+    }
+}
+
+impl From<status::InvalidStatusCode> for DecoderError {
+    fn from(_: status::InvalidStatusCode) -> DecoderError {
+        // TODO: Better error
+        DecoderError::InvalidUtf8
+    }
+}
+
+impl From<DecoderError> for frame::Error {
+    fn from(src: DecoderError) -> Self {
+        frame::Error::Hpack(src)
+    }
+}
+
+/// Get an entry from the static table
+pub fn get_static(idx: usize) -> Header {
+    use http::header::HeaderValue;
+
+    match idx {
+        1 => Header::Authority(BytesStr::from_static("")),
+        2 => Header::Method(Method::GET),
+        3 => Header::Method(Method::POST),
+        4 => Header::Path(BytesStr::from_static("/")),
+        5 => Header::Path(BytesStr::from_static("/index.html")),
+        6 => Header::Scheme(BytesStr::from_static("http")),
+        7 => Header::Scheme(BytesStr::from_static("https")),
+        8 => Header::Status(StatusCode::OK),
+        9 => Header::Status(StatusCode::NO_CONTENT),
+        10 => Header::Status(StatusCode::PARTIAL_CONTENT),
+        11 => Header::Status(StatusCode::NOT_MODIFIED),
+        12 => Header::Status(StatusCode::BAD_REQUEST),
+        13 => Header::Status(StatusCode::NOT_FOUND),
+        14 => Header::Status(StatusCode::INTERNAL_SERVER_ERROR),
+        15 => Header::Field {
+            name: header::ACCEPT_CHARSET,
+            value: HeaderValue::from_static(""),
+        },
+        16 => Header::Field {
+            name: header::ACCEPT_ENCODING,
+            value: HeaderValue::from_static("gzip, deflate"),
+        },
+        17 => Header::Field {
+            name: header::ACCEPT_LANGUAGE,
+            value: HeaderValue::from_static(""),
+        },
+        18 => Header::Field {
+            name: header::ACCEPT_RANGES,
+            value: HeaderValue::from_static(""),
+        },
+        19 => Header::Field {
+            name: header::ACCEPT,
+            value: HeaderValue::from_static(""),
+        },
+        20 => Header::Field {
+            name: header::ACCESS_CONTROL_ALLOW_ORIGIN,
+            value: HeaderValue::from_static(""),
+        },
+        21 => Header::Field {
+            name: header::AGE,
+            value: HeaderValue::from_static(""),
+        },
+        22 => Header::Field {
+            name: header::ALLOW,
+            value: HeaderValue::from_static(""),
+        },
+        23 => Header::Field {
+            name: header::AUTHORIZATION,
+            value: HeaderValue::from_static(""),
+        },
+        24 => Header::Field {
+            name: header::CACHE_CONTROL,
+            value: HeaderValue::from_static(""),
+        },
+        25 => Header::Field {
+            name: header::CONTENT_DISPOSITION,
+            value: HeaderValue::from_static(""),
+        },
+        26 => Header::Field {
+            name: header::CONTENT_ENCODING,
+            value: HeaderValue::from_static(""),
+        },
+        27 => Header::Field {
+            name: header::CONTENT_LANGUAGE,
+            value: HeaderValue::from_static(""),
+        },
+        28 => Header::Field {
+            name: header::CONTENT_LENGTH,
+            value: HeaderValue::from_static(""),
+        },
+        29 => Header::Field {
+            name: header::CONTENT_LOCATION,
+            value: HeaderValue::from_static(""),
+        },
+        30 => Header::Field {
+            name: header::CONTENT_RANGE,
+            value: HeaderValue::from_static(""),
+        },
+        31 => Header::Field {
+            name: header::CONTENT_TYPE,
+            value: HeaderValue::from_static(""),
+        },
+        32 => Header::Field {
+            name: header::COOKIE,
+            value: HeaderValue::from_static(""),
+        },
+        33 => Header::Field {
+            name: header::DATE,
+            value: HeaderValue::from_static(""),
+        },
+        34 => Header::Field {
+            name: header::ETAG,
+            value: HeaderValue::from_static(""),
+        },
+        35 => Header::Field {
+            name: header::EXPECT,
+            value: HeaderValue::from_static(""),
+        },
+        36 => Header::Field {
+            name: header::EXPIRES,
+            value: HeaderValue::from_static(""),
+        },
+        37 => Header::Field {
+            name: header::FROM,
+            value: HeaderValue::from_static(""),
+        },
+        38 => Header::Field {
+            name: header::HOST,
+            value: HeaderValue::from_static(""),
+        },
+        39 => Header::Field {
+            name: header::IF_MATCH,
+            value: HeaderValue::from_static(""),
+        },
+        40 => Header::Field {
+            name: header::IF_MODIFIED_SINCE,
+            value: HeaderValue::from_static(""),
+        },
+        41 => Header::Field {
+            name: header::IF_NONE_MATCH,
+            value: HeaderValue::from_static(""),
+        },
+        42 => Header::Field {
+            name: header::IF_RANGE,
+            value: HeaderValue::from_static(""),
+        },
+        43 => Header::Field {
+            name: header::IF_UNMODIFIED_SINCE,
+            value: HeaderValue::from_static(""),
+        },
+        44 => Header::Field {
+            name: header::LAST_MODIFIED,
+            value: HeaderValue::from_static(""),
+        },
+        45 => Header::Field {
+            name: header::LINK,
+            value: HeaderValue::from_static(""),
+        },
+        46 => Header::Field {
+            name: header::LOCATION,
+            value: HeaderValue::from_static(""),
+        },
+        47 => Header::Field {
+            name: header::MAX_FORWARDS,
+            value: HeaderValue::from_static(""),
+        },
+        48 => Header::Field {
+            name: header::PROXY_AUTHENTICATE,
+            value: HeaderValue::from_static(""),
+        },
+        49 => Header::Field {
+            name: header::PROXY_AUTHORIZATION,
+            value: HeaderValue::from_static(""),
+        },
+        50 => Header::Field {
+            name: header::RANGE,
+            value: HeaderValue::from_static(""),
+        },
+        51 => Header::Field {
+            name: header::REFERER,
+            value: HeaderValue::from_static(""),
+        },
+        52 => Header::Field {
+            name: header::REFRESH,
+            value: HeaderValue::from_static(""),
+        },
+        53 => Header::Field {
+            name: header::RETRY_AFTER,
+            value: HeaderValue::from_static(""),
+        },
+        54 => Header::Field {
+            name: header::SERVER,
+            value: HeaderValue::from_static(""),
+        },
+        55 => Header::Field {
+            name: header::SET_COOKIE,
+            value: HeaderValue::from_static(""),
+        },
+        56 => Header::Field {
+            name: header::STRICT_TRANSPORT_SECURITY,
+            value: HeaderValue::from_static(""),
+        },
+        57 => Header::Field {
+            name: header::TRANSFER_ENCODING,
+            value: HeaderValue::from_static(""),
+        },
+        58 => Header::Field {
+            name: header::USER_AGENT,
+            value: HeaderValue::from_static(""),
+        },
+        59 => Header::Field {
+            name: header::VARY,
+            value: HeaderValue::from_static(""),
+        },
+        60 => Header::Field {
+            name: header::VIA,
+            value: HeaderValue::from_static(""),
+        },
+        61 => Header::Field {
+            name: header::WWW_AUTHENTICATE,
+            value: HeaderValue::from_static(""),
+        },
+        _ => unreachable!(),
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_peek_u8() {
+        let b = 0xff;
+        let mut buf = Cursor::new(vec![b]);
+        assert_eq!(peek_u8(&buf), Some(b));
+        assert_eq!(buf.get_u8(), b);
+        assert_eq!(peek_u8(&buf), None);
+    }
+
+    #[test]
+    fn test_decode_string_empty() {
+        let mut de = Decoder::new(0);
+        let mut buf = BytesMut::new();
+        let err = de.decode_string(&mut Cursor::new(&mut buf)).unwrap_err();
+        assert_eq!(err, DecoderError::NeedMore(NeedMore::UnexpectedEndOfStream));
+    }
+
+    #[test]
+    fn test_decode_empty() {
+        let mut de = Decoder::new(0);
+        let mut buf = BytesMut::new();
+        let _: () = de.decode(&mut Cursor::new(&mut buf), |_| {}).unwrap();
+    }
+
+    #[test]
+    fn test_decode_indexed_larger_than_table() {
+        let mut de = Decoder::new(0);
+
+        let mut buf = BytesMut::new();
+        buf.extend([0b01000000, 0x80 | 2]);
+        buf.extend(huff_encode(b"foo"));
+        buf.extend([0x80 | 3]);
+        buf.extend(huff_encode(b"bar"));
+
+        let mut res = vec![];
+        de.decode(&mut Cursor::new(&mut buf), |h| {
+            res.push(h);
+        })
+        .unwrap();
+
+        assert_eq!(res.len(), 1);
+        assert_eq!(de.table.size(), 0);
+
+        match res[0] {
+            Header::Field {
+                ref name,
+                ref value,
+            } => {
+                assert_eq!(name, "foo");
+                assert_eq!(value, "bar");
+            }
+            _ => panic!(),
+        }
+    }
+
+    fn huff_encode(src: &[u8]) -> BytesMut {
+        let mut buf = BytesMut::new();
+        huffman::encode(src, &mut buf);
+        buf
+    }
+
+    #[test]
+    fn test_decode_continuation_header_with_non_huff_encoded_name() {
+        let mut de = Decoder::new(0);
+        let value = huff_encode(b"bar");
+        let mut buf = BytesMut::new();
+        // header name is non_huff encoded
+        buf.extend([0b01000000, 3]);
+        buf.extend(b"foo");
+        // header value is partial
+        buf.extend([0x80 | 3]);
+        buf.extend(&value[0..1]);
+
+        let mut res = vec![];
+        let e = de
+            .decode(&mut Cursor::new(&mut buf), |h| {
+                res.push(h);
+            })
+            .unwrap_err();
+        // decode error because the header value is partial
+        assert_eq!(e, DecoderError::NeedMore(NeedMore::StringUnderflow));
+
+        // extend buf with the remaining header value
+        buf.extend(&value[1..]);
+        de.decode(&mut Cursor::new(&mut buf), |h| {
+            res.push(h);
+        })
+        .unwrap();
+
+        assert_eq!(res.len(), 1);
+        assert_eq!(de.table.size(), 0);
+
+        match res[0] {
+            Header::Field {
+                ref name,
+                ref value,
+            } => {
+                assert_eq!(name, "foo");
+                assert_eq!(value, "bar");
+            }
+            _ => panic!(),
+        }
+    }
+}

vendor/h2/src/hpack/encoder.rs

@@ -0,0 +1,720 @@
+use super::table::{Index, Table};
+use super::{huffman, Header};
+
+use bytes::{BufMut, BytesMut};
+use http::header::{HeaderName, HeaderValue};
+
+#[derive(Debug)]
+pub struct Encoder {
+    table: Table,
+    size_update: Option<SizeUpdate>,
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+enum SizeUpdate {
+    One(usize),
+    Two(usize, usize), // min, max
+}
+
+impl Encoder {
+    pub fn new(max_size: usize, capacity: usize) -> Encoder {
+        Encoder {
+            table: Table::new(max_size, capacity),
+            size_update: None,
+        }
+    }
+
+    /// Queues a max size update.
+    ///
+    /// The next call to `encode` will include a dynamic size update frame.
+    pub fn update_max_size(&mut self, val: usize) {
+        match self.size_update {
+            Some(SizeUpdate::One(old)) => {
+                if val > old {
+                    if old > self.table.max_size() {
+                        self.size_update = Some(SizeUpdate::One(val));
+                    } else {
+                        self.size_update = Some(SizeUpdate::Two(old, val));
+                    }
+                } else {
+                    self.size_update = Some(SizeUpdate::One(val));
+                }
+            }
+            Some(SizeUpdate::Two(min, _)) => {
+                if val < min {
+                    self.size_update = Some(SizeUpdate::One(val));
+                } else {
+                    self.size_update = Some(SizeUpdate::Two(min, val));
+                }
+            }
+            None => {
+                if val != self.table.max_size() {
+                    // Don't bother writing a frame if the value already matches
+                    // the table's max size.
+                    self.size_update = Some(SizeUpdate::One(val));
+                }
+            }
+        }
+    }
+
+    /// Encode a set of headers into the provide buffer
+    pub fn encode<I>(&mut self, headers: I, dst: &mut BytesMut)
+    where
+        I: IntoIterator<Item = Header<Option<HeaderName>>>,
+    {
+        let span = tracing::trace_span!("hpack::encode");
+        let _e = span.enter();
+
+        self.encode_size_updates(dst);
+
+        let mut last_index = None;
+
+        for header in headers {
+            match header.reify() {
+                // The header has an associated name. In which case, try to
+                // index it in the table.
+                Ok(header) => {
+                    let index = self.table.index(header);
+                    self.encode_header(&index, dst);
+
+                    last_index = Some(index);
+                }
+                // The header does not have an associated name. This means that
+                // the name is the same as the previously yielded header. In
+                // which case, we skip table lookup and just use the same index
+                // as the previous entry.
+                Err(value) => {
+                    self.encode_header_without_name(
+                        last_index.as_ref().unwrap_or_else(|| {
+                            panic!("encoding header without name, but no previous index to use for name");
+                        }),
+                        &value,
+                        dst,
+                    );
+                }
+            }
+        }
+    }
+
+    fn encode_size_updates(&mut self, dst: &mut BytesMut) {
+        match self.size_update.take() {
+            Some(SizeUpdate::One(val)) => {
+                self.table.resize(val);
+                encode_size_update(val, dst);
+            }
+            Some(SizeUpdate::Two(min, max)) => {
+                self.table.resize(min);
+                self.table.resize(max);
+                encode_size_update(min, dst);
+                encode_size_update(max, dst);
+            }
+            None => {}
+        }
+    }
+
+    fn encode_header(&mut self, index: &Index, dst: &mut BytesMut) {
+        match *index {
+            Index::Indexed(idx, _) => {
+                encode_int(idx, 7, 0x80, dst);
+            }
+            Index::Name(idx, _) => {
+                let header = self.table.resolve(index);
+
+                encode_not_indexed(idx, header.value_slice(), header.is_sensitive(), dst);
+            }
+            Index::Inserted(_) => {
+                let header = self.table.resolve(index);
+
+                assert!(!header.is_sensitive());
+
+                dst.put_u8(0b0100_0000);
+
+                encode_str(header.name().as_slice(), dst);
+                encode_str(header.value_slice(), dst);
+            }
+            Index::InsertedValue(idx, _) => {
+                let header = self.table.resolve(index);
+
+                assert!(!header.is_sensitive());
+
+                encode_int(idx, 6, 0b0100_0000, dst);
+                encode_str(header.value_slice(), dst);
+            }
+            Index::NotIndexed(_) => {
+                let header = self.table.resolve(index);
+
+                encode_not_indexed2(
+                    header.name().as_slice(),
+                    header.value_slice(),
+                    header.is_sensitive(),
+                    dst,
+                );
+            }
+        }
+    }
+
+    fn encode_header_without_name(
+        &mut self,
+        last: &Index,
+        value: &HeaderValue,
+        dst: &mut BytesMut,
+    ) {
+        match *last {
+            Index::Indexed(..)
+            | Index::Name(..)
+            | Index::Inserted(..)
+            | Index::InsertedValue(..) => {
+                let idx = self.table.resolve_idx(last);
+
+                encode_not_indexed(idx, value.as_ref(), value.is_sensitive(), dst);
+            }
+            Index::NotIndexed(_) => {
+                let last = self.table.resolve(last);
+
+                encode_not_indexed2(
+                    last.name().as_slice(),
+                    value.as_ref(),
+                    value.is_sensitive(),
+                    dst,
+                );
+            }
+        }
+    }
+}
+
+impl Default for Encoder {
+    fn default() -> Encoder {
+        Encoder::new(4096, 0)
+    }
+}
+
+fn encode_size_update(val: usize, dst: &mut BytesMut) {
+    encode_int(val, 5, 0b0010_0000, dst)
+}
+
+fn encode_not_indexed(name: usize, value: &[u8], sensitive: bool, dst: &mut BytesMut) {
+    if sensitive {
+        encode_int(name, 4, 0b10000, dst);
+    } else {
+        encode_int(name, 4, 0, dst);
+    }
+
+    encode_str(value, dst);
+}
+
+fn encode_not_indexed2(name: &[u8], value: &[u8], sensitive: bool, dst: &mut BytesMut) {
+    if sensitive {
+        dst.put_u8(0b10000);
+    } else {
+        dst.put_u8(0);
+    }
+
+    encode_str(name, dst);
+    encode_str(value, dst);
+}
+
+fn encode_str(val: &[u8], dst: &mut BytesMut) {
+    if !val.is_empty() {
+        let idx = position(dst);
+
+        // Push a placeholder byte for the length header
+        dst.put_u8(0);
+
+        // Encode with huffman
+        huffman::encode(val, dst);
+
+        let huff_len = position(dst) - (idx + 1);
+
+        if encode_int_one_byte(huff_len, 7) {
+            // Write the string head
+            dst[idx] = 0x80 | huff_len as u8;
+        } else {
+            // Write the head to a placeholder
+            const PLACEHOLDER_LEN: usize = 8;
+            let mut buf = [0u8; PLACEHOLDER_LEN];
+
+            let head_len = {
+                let mut head_dst = &mut buf[..];
+                encode_int(huff_len, 7, 0x80, &mut head_dst);
+                PLACEHOLDER_LEN - head_dst.remaining_mut()
+            };
+
+            // This is just done to reserve space in the destination
+            dst.put_slice(&buf[1..head_len]);
+
+            // Shift the header forward
+            for i in 0..huff_len {
+                let src_i = idx + 1 + (huff_len - (i + 1));
+                let dst_i = idx + head_len + (huff_len - (i + 1));
+                dst[dst_i] = dst[src_i];
+            }
+
+            // Copy in the head
+            for i in 0..head_len {
+                dst[idx + i] = buf[i];
+            }
+        }
+    } else {
+        // Write an empty string
+        dst.put_u8(0);
+    }
+}
+
+/// Encode an integer into the given destination buffer
+fn encode_int<B: BufMut>(
+    mut value: usize,   // The integer to encode
+    prefix_bits: usize, // The number of bits in the prefix
+    first_byte: u8,     // The base upon which to start encoding the int
+    dst: &mut B,
+) {
+    if encode_int_one_byte(value, prefix_bits) {
+        dst.put_u8(first_byte | value as u8);
+        return;
+    }
+
+    let low = (1 << prefix_bits) - 1;
+
+    value -= low;
+
+    dst.put_u8(first_byte | low as u8);
+
+    while value >= 128 {
+        dst.put_u8(0b1000_0000 | value as u8);
+
+        value >>= 7;
+    }
+
+    dst.put_u8(value as u8);
+}
+
+/// Returns true if the in the int can be fully encoded in the first byte.
+fn encode_int_one_byte(value: usize, prefix_bits: usize) -> bool {
+    value < (1 << prefix_bits) - 1
+}
+
+fn position(buf: &BytesMut) -> usize {
+    buf.len()
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use http::*;
+
+    #[test]
+    fn test_encode_method_get() {
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![method("GET")]);
+        assert_eq!(*res, [0x80 | 2]);
+        assert_eq!(encoder.table.len(), 0);
+    }
+
+    #[test]
+    fn test_encode_method_post() {
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![method("POST")]);
+        assert_eq!(*res, [0x80 | 3]);
+        assert_eq!(encoder.table.len(), 0);
+    }
+
+    #[test]
+    fn test_encode_method_patch() {
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![method("PATCH")]);
+
+        assert_eq!(res[0], 0b01000000 | 2); // Incremental indexing w/ name pulled from table
+        assert_eq!(res[1], 0x80 | 5); // header value w/ huffman coding
+
+        assert_eq!("PATCH", huff_decode(&res[2..7]));
+        assert_eq!(encoder.table.len(), 1);
+
+        let res = encode(&mut encoder, vec![method("PATCH")]);
+
+        assert_eq!(1 << 7 | 62, res[0]);
+        assert_eq!(1, res.len());
+    }
+
+    #[test]
+    fn test_encode_indexed_name_literal_value() {
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![header("content-language", "foo")]);
+
+        assert_eq!(res[0], 0b01000000 | 27); // Indexed name
+        assert_eq!(res[1], 0x80 | 2); // header value w/ huffman coding
+
+        assert_eq!("foo", huff_decode(&res[2..4]));
+
+        // Same name, new value should still use incremental
+        let res = encode(&mut encoder, vec![header("content-language", "bar")]);
+        assert_eq!(res[0], 0b01000000 | 27); // Indexed name
+        assert_eq!(res[1], 0x80 | 3); // header value w/ huffman coding
+        assert_eq!("bar", huff_decode(&res[2..5]));
+    }
+
+    #[test]
+    fn test_repeated_headers_are_indexed() {
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![header("foo", "hello")]);
+
+        assert_eq!(&[0b01000000, 0x80 | 2], &res[0..2]);
+        assert_eq!("foo", huff_decode(&res[2..4]));
+        assert_eq!(0x80 | 4, res[4]);
+        assert_eq!("hello", huff_decode(&res[5..]));
+        assert_eq!(9, res.len());
+
+        assert_eq!(1, encoder.table.len());
+
+        let res = encode(&mut encoder, vec![header("foo", "hello")]);
+        assert_eq!([0x80 | 62], *res);
+
+        assert_eq!(encoder.table.len(), 1);
+    }
+
+    #[test]
+    fn test_evicting_headers() {
+        let mut encoder = Encoder::default();
+
+        // Fill the table
+        for i in 0..64 {
+            let key = format!("x-hello-world-{:02}", i);
+            let res = encode(&mut encoder, vec![header(&key, &key)]);
+
+            assert_eq!(&[0b01000000, 0x80 | 12], &res[0..2]);
+            assert_eq!(key, huff_decode(&res[2..14]));
+            assert_eq!(0x80 | 12, res[14]);
+            assert_eq!(key, huff_decode(&res[15..]));
+            assert_eq!(27, res.len());
+
+            // Make sure the header can be found...
+            let res = encode(&mut encoder, vec![header(&key, &key)]);
+
+            // Only check that it is found
+            assert_eq!(0x80, res[0] & 0x80);
+        }
+
+        assert_eq!(4096, encoder.table.size());
+        assert_eq!(64, encoder.table.len());
+
+        // Find existing headers
+        for i in 0..64 {
+            let key = format!("x-hello-world-{:02}", i);
+            let res = encode(&mut encoder, vec![header(&key, &key)]);
+            assert_eq!(0x80, res[0] & 0x80);
+        }
+
+        // Insert a new header
+        let key = "x-hello-world-64";
+        let res = encode(&mut encoder, vec![header(key, key)]);
+
+        assert_eq!(&[0b01000000, 0x80 | 12], &res[0..2]);
+        assert_eq!(key, huff_decode(&res[2..14]));
+        assert_eq!(0x80 | 12, res[14]);
+        assert_eq!(key, huff_decode(&res[15..]));
+        assert_eq!(27, res.len());
+
+        assert_eq!(64, encoder.table.len());
+
+        // Now try encoding entries that should exist in the table
+        for i in 1..65 {
+            let key = format!("x-hello-world-{:02}", i);
+            let res = encode(&mut encoder, vec![header(&key, &key)]);
+            assert_eq!(0x80 | (61 + (65 - i)), res[0]);
+        }
+    }
+
+    #[test]
+    fn test_large_headers_are_not_indexed() {
+        let mut encoder = Encoder::new(128, 0);
+        let key = "hello-world-hello-world-HELLO-zzz";
+
+        let res = encode(&mut encoder, vec![header(key, key)]);
+
+        assert_eq!(&[0, 0x80 | 25], &res[..2]);
+
+        assert_eq!(0, encoder.table.len());
+        assert_eq!(0, encoder.table.size());
+    }
+
+    #[test]
+    fn test_sensitive_headers_are_never_indexed() {
+        use http::header::HeaderValue;
+
+        let name = "my-password".parse().unwrap();
+        let mut value = HeaderValue::from_bytes(b"12345").unwrap();
+        value.set_sensitive(true);
+
+        let header = Header::Field {
+            name: Some(name),
+            value,
+        };
+
+        // Now, try to encode the sensitive header
+
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![header]);
+
+        assert_eq!(&[0b10000, 0x80 | 8], &res[..2]);
+        assert_eq!("my-password", huff_decode(&res[2..10]));
+        assert_eq!(0x80 | 4, res[10]);
+        assert_eq!("12345", huff_decode(&res[11..]));
+
+        // Now, try to encode a sensitive header w/ a name in the static table
+        let name = "authorization".parse().unwrap();
+        let mut value = HeaderValue::from_bytes(b"12345").unwrap();
+        value.set_sensitive(true);
+
+        let header = Header::Field {
+            name: Some(name),
+            value,
+        };
+
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![header]);
+
+        assert_eq!(&[0b11111, 8], &res[..2]);
+        assert_eq!(0x80 | 4, res[2]);
+        assert_eq!("12345", huff_decode(&res[3..]));
+
+        // Using the name component of a previously indexed header (without
+        // sensitive flag set)
+
+        let _ = encode(
+            &mut encoder,
+            vec![self::header("my-password", "not-so-secret")],
+        );
+
+        let name = "my-password".parse().unwrap();
+        let mut value = HeaderValue::from_bytes(b"12345").unwrap();
+        value.set_sensitive(true);
+
+        let header = Header::Field {
+            name: Some(name),
+            value,
+        };
+        let res = encode(&mut encoder, vec![header]);
+
+        assert_eq!(&[0b11111, 47], &res[..2]);
+        assert_eq!(0x80 | 4, res[2]);
+        assert_eq!("12345", huff_decode(&res[3..]));
+    }
+
+    #[test]
+    fn test_content_length_value_not_indexed() {
+        let mut encoder = Encoder::default();
+        let res = encode(&mut encoder, vec![header("content-length", "1234")]);
+
+        assert_eq!(&[15, 13, 0x80 | 3], &res[0..3]);
+        assert_eq!("1234", huff_decode(&res[3..]));
+        assert_eq!(6, res.len());
+    }
+
+    #[test]
+    fn test_encoding_headers_with_same_name() {
+        let mut encoder = Encoder::default();
+        let name = "hello";
+
+        // Encode first one
+        let _ = encode(&mut encoder, vec![header(name, "one")]);
+
+        // Encode second one
+        let res = encode(&mut encoder, vec![header(name, "two")]);
+        assert_eq!(&[0x40 | 62, 0x80 | 3], &res[0..2]);
+        assert_eq!("two", huff_decode(&res[2..]));
+        assert_eq!(5, res.len());
+
+        // Encode the first one again
+        let res = encode(&mut encoder, vec![header(name, "one")]);
+        assert_eq!(&[0x80 | 63], &res[..]);
+
+        // Now the second one
+        let res = encode(&mut encoder, vec![header(name, "two")]);
+        assert_eq!(&[0x80 | 62], &res[..]);
+    }
+
+    #[test]
+    fn test_evicting_headers_when_multiple_of_same_name_are_in_table() {
+        // The encoder only has space for 2 headers
+        let mut encoder = Encoder::new(76, 0);
+
+        let _ = encode(&mut encoder, vec![header("foo", "bar")]);
+        assert_eq!(1, encoder.table.len());
+
+        let _ = encode(&mut encoder, vec![header("bar", "foo")]);
+        assert_eq!(2, encoder.table.len());
+
+        // This will evict the first header, while still referencing the header
+        // name
+        let res = encode(&mut encoder, vec![header("foo", "baz")]);
+        assert_eq!(&[0x40 | 63, 0, 0x80 | 3], &res[..3]);
+        assert_eq!(2, encoder.table.len());
+
+        // Try adding the same header again
+        let res = encode(&mut encoder, vec![header("foo", "baz")]);
+        assert_eq!(&[0x80 | 62], &res[..]);
+        assert_eq!(2, encoder.table.len());
+    }
+
+    #[test]
+    fn test_max_size_zero() {
+        // Static table only
+        let mut encoder = Encoder::new(0, 0);
+        let res = encode(&mut encoder, vec![method("GET")]);
+        assert_eq!(*res, [0x80 | 2]);
+        assert_eq!(encoder.table.len(), 0);
+
+        let res = encode(&mut encoder, vec![header("foo", "bar")]);
+        assert_eq!(&[0, 0x80 | 2], &res[..2]);
+        assert_eq!("foo", huff_decode(&res[2..4]));
+        assert_eq!(0x80 | 3, res[4]);
+        assert_eq!("bar", huff_decode(&res[5..8]));
+        assert_eq!(0, encoder.table.len());
+
+        // Encode a custom value
+        let res = encode(&mut encoder, vec![header("transfer-encoding", "chunked")]);
+        assert_eq!(&[15, 42, 0x80 | 6], &res[..3]);
+        assert_eq!("chunked", huff_decode(&res[3..]));
+    }
+
+    #[test]
+    fn test_update_max_size_combos() {
+        let mut encoder = Encoder::default();
+        assert!(encoder.size_update.is_none());
+        assert_eq!(4096, encoder.table.max_size());
+
+        encoder.update_max_size(4096); // Default size
+        assert!(encoder.size_update.is_none());
+
+        encoder.update_max_size(0);
+        assert_eq!(Some(SizeUpdate::One(0)), encoder.size_update);
+
+        encoder.update_max_size(100);
+        assert_eq!(Some(SizeUpdate::Two(0, 100)), encoder.size_update);
+
+        let mut encoder = Encoder::default();
+        encoder.update_max_size(8000);
+        assert_eq!(Some(SizeUpdate::One(8000)), encoder.size_update);
+
+        encoder.update_max_size(100);
+        assert_eq!(Some(SizeUpdate::One(100)), encoder.size_update);
+
+        encoder.update_max_size(8000);
+        assert_eq!(Some(SizeUpdate::Two(100, 8000)), encoder.size_update);
+
+        encoder.update_max_size(4000);
+        assert_eq!(Some(SizeUpdate::Two(100, 4000)), encoder.size_update);
+
+        encoder.update_max_size(50);
+        assert_eq!(Some(SizeUpdate::One(50)), encoder.size_update);
+    }
+
+    #[test]
+    fn test_resizing_table() {
+        let mut encoder = Encoder::default();
+
+        // Add a header
+        let _ = encode(&mut encoder, vec![header("foo", "bar")]);
+
+        encoder.update_max_size(1);
+        assert_eq!(1, encoder.table.len());
+
+        let res = encode(&mut encoder, vec![method("GET")]);
+        assert_eq!(&[32 | 1, 0x80 | 2], &res[..]);
+        assert_eq!(0, encoder.table.len());
+
+        let res = encode(&mut encoder, vec![header("foo", "bar")]);
+        assert_eq!(0, res[0]);
+
+        encoder.update_max_size(100);
+        let res = encode(&mut encoder, vec![header("foo", "bar")]);
+        assert_eq!(&[32 | 31, 69, 64], &res[..3]);
+
+        encoder.update_max_size(0);
+        let res = encode(&mut encoder, vec![header("foo", "bar")]);
+        assert_eq!(&[32, 0], &res[..2]);
+    }
+
+    #[test]
+    fn test_decreasing_table_size_without_eviction() {
+        let mut encoder = Encoder::default();
+
+        // Add a header
+        let _ = encode(&mut encoder, vec![header("foo", "bar")]);
+
+        encoder.update_max_size(100);
+        assert_eq!(1, encoder.table.len());
+
+        let res = encode(&mut encoder, vec![header("foo", "bar")]);
+        assert_eq!(&[32 | 31, 69, 0x80 | 62], &res[..]);
+    }
+
+    #[test]
+    fn test_nameless_header() {
+        let mut encoder = Encoder::default();
+
+        let res = encode(
+            &mut encoder,
+            vec![
+                Header::Field {
+                    name: Some("hello".parse().unwrap()),
+                    value: HeaderValue::from_bytes(b"world").unwrap(),
+                },
+                Header::Field {
+                    name: None,
+                    value: HeaderValue::from_bytes(b"zomg").unwrap(),
+                },
+            ],
+        );
+
+        assert_eq!(&[0x40, 0x80 | 4], &res[0..2]);
+        assert_eq!("hello", huff_decode(&res[2..6]));
+        assert_eq!(0x80 | 4, res[6]);
+        assert_eq!("world", huff_decode(&res[7..11]));
+
+        // Next is not indexed
+        assert_eq!(&[15, 47, 0x80 | 3], &res[11..14]);
+        assert_eq!("zomg", huff_decode(&res[14..]));
+    }
+
+    #[test]
+    fn test_large_size_update() {
+        let mut encoder = Encoder::default();
+
+        encoder.update_max_size(1912930560);
+        assert_eq!(Some(SizeUpdate::One(1912930560)), encoder.size_update);
+
+        let mut dst = BytesMut::with_capacity(6);
+        encoder.encode_size_updates(&mut dst);
+        assert_eq!([63, 225, 129, 148, 144, 7], &dst[..]);
+    }
+
+    #[test]
+    #[ignore]
+    fn test_evicted_overflow() {
+        // Not sure what the best way to do this is.
+    }
+
+    fn encode(e: &mut Encoder, hdrs: Vec<Header<Option<HeaderName>>>) -> BytesMut {
+        let mut dst = BytesMut::with_capacity(1024);
+        e.encode(hdrs, &mut dst);
+        dst
+    }
+
+    fn method(s: &str) -> Header<Option<HeaderName>> {
+        Header::Method(Method::from_bytes(s.as_bytes()).unwrap())
+    }
+
+    fn header(name: &str, val: &str) -> Header<Option<HeaderName>> {
+        let name = HeaderName::from_bytes(name.as_bytes()).unwrap();
+        let value = HeaderValue::from_bytes(val.as_bytes()).unwrap();
+
+        Header::Field {
+            name: Some(name),
+            value,
+        }
+    }
+
+    fn huff_decode(src: &[u8]) -> BytesMut {
+        let mut buf = BytesMut::new();
+        huffman::decode(src, &mut buf).unwrap()
+    }
+}

vendor/h2/src/hpack/header.rs

@@ -0,0 +1,308 @@
+use super::{DecoderError, NeedMore};
+use crate::ext::Protocol;
+
+use bytes::Bytes;
+use http::header::{HeaderName, HeaderValue};
+use http::{Method, StatusCode};
+use std::fmt;
+
+/// HTTP/2 Header
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Header<T = HeaderName> {
+    Field { name: T, value: HeaderValue },
+    // TODO: Change these types to `http::uri` types.
+    Authority(BytesStr),
+    Method(Method),
+    Scheme(BytesStr),
+    Path(BytesStr),
+    Protocol(Protocol),
+    Status(StatusCode),
+}
+
+/// The header field name
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+pub enum Name<'a> {
+    Field(&'a HeaderName),
+    Authority,
+    Method,
+    Scheme,
+    Path,
+    Protocol,
+    Status,
+}
+
+#[doc(hidden)]
+#[derive(Clone, Eq, PartialEq, Default)]
+pub struct BytesStr(Bytes);
+
+pub fn len(name: &HeaderName, value: &HeaderValue) -> usize {
+    let n: &str = name.as_ref();
+    32 + n.len() + value.len()
+}
+
+impl Header<Option<HeaderName>> {
+    pub fn reify(self) -> Result<Header, HeaderValue> {
+        use self::Header::*;
+
+        Ok(match self {
+            Field {
+                name: Some(n),
+                value,
+            } => Field { name: n, value },
+            Field { name: None, value } => return Err(value),
+            Authority(v) => Authority(v),
+            Method(v) => Method(v),
+            Scheme(v) => Scheme(v),
+            Path(v) => Path(v),
+            Protocol(v) => Protocol(v),
+            Status(v) => Status(v),
+        })
+    }
+}
+
+impl Header {
+    pub fn new(name: Bytes, value: Bytes) -> Result<Header, DecoderError> {
+        if name.is_empty() {
+            return Err(DecoderError::NeedMore(NeedMore::UnexpectedEndOfStream));
+        }
+        if name[0] == b':' {
+            match &name[1..] {
+                b"authority" => {
+                    let value = BytesStr::try_from(value)?;
+                    Ok(Header::Authority(value))
+                }
+                b"method" => {
+                    let method = Method::from_bytes(&value)?;
+                    Ok(Header::Method(method))
+                }
+                b"scheme" => {
+                    let value = BytesStr::try_from(value)?;
+                    Ok(Header::Scheme(value))
+                }
+                b"path" => {
+                    let value = BytesStr::try_from(value)?;
+                    Ok(Header::Path(value))
+                }
+                b"protocol" => {
+                    let value = Protocol::try_from(value)?;
+                    Ok(Header::Protocol(value))
+                }
+                b"status" => {
+                    let status = StatusCode::from_bytes(&value)?;
+                    Ok(Header::Status(status))
+                }
+                _ => Err(DecoderError::InvalidPseudoheader),
+            }
+        } else {
+            // HTTP/2 requires lower case header names
+            let name = HeaderName::from_lowercase(&name)?;
+            let value = HeaderValue::from_bytes(&value)?;
+
+            Ok(Header::Field { name, value })
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        match *self {
+            Header::Field {
+                ref name,
+                ref value,
+            } => len(name, value),
+            Header::Authority(ref v) => 32 + 10 + v.len(),
+            Header::Method(ref v) => 32 + 7 + v.as_ref().len(),
+            Header::Scheme(ref v) => 32 + 7 + v.len(),
+            Header::Path(ref v) => 32 + 5 + v.len(),
+            Header::Protocol(ref v) => 32 + 9 + v.as_str().len(),
+            Header::Status(_) => 32 + 7 + 3,
+        }
+    }
+
+    /// Returns the header name
+    pub fn name(&self) -> Name<'_> {
+        match *self {
+            Header::Field { ref name, .. } => Name::Field(name),
+            Header::Authority(..) => Name::Authority,
+            Header::Method(..) => Name::Method,
+            Header::Scheme(..) => Name::Scheme,
+            Header::Path(..) => Name::Path,
+            Header::Protocol(..) => Name::Protocol,
+            Header::Status(..) => Name::Status,
+        }
+    }
+
+    pub fn value_slice(&self) -> &[u8] {
+        match *self {
+            Header::Field { ref value, .. } => value.as_ref(),
+            Header::Authority(ref v) => v.as_ref(),
+            Header::Method(ref v) => v.as_ref().as_ref(),
+            Header::Scheme(ref v) => v.as_ref(),
+            Header::Path(ref v) => v.as_ref(),
+            Header::Protocol(ref v) => v.as_ref(),
+            Header::Status(ref v) => v.as_str().as_ref(),
+        }
+    }
+
+    pub fn value_eq(&self, other: &Header) -> bool {
+        match *self {
+            Header::Field { ref value, .. } => {
+                let a = value;
+                match *other {
+                    Header::Field { ref value, .. } => a == value,
+                    _ => false,
+                }
+            }
+            Header::Authority(ref a) => match *other {
+                Header::Authority(ref b) => a == b,
+                _ => false,
+            },
+            Header::Method(ref a) => match *other {
+                Header::Method(ref b) => a == b,
+                _ => false,
+            },
+            Header::Scheme(ref a) => match *other {
+                Header::Scheme(ref b) => a == b,
+                _ => false,
+            },
+            Header::Path(ref a) => match *other {
+                Header::Path(ref b) => a == b,
+                _ => false,
+            },
+            Header::Protocol(ref a) => match *other {
+                Header::Protocol(ref b) => a == b,
+                _ => false,
+            },
+            Header::Status(ref a) => match *other {
+                Header::Status(ref b) => a == b,
+                _ => false,
+            },
+        }
+    }
+
+    pub fn is_sensitive(&self) -> bool {
+        match *self {
+            Header::Field { ref value, .. } => value.is_sensitive(),
+            // TODO: Technically these other header values can be sensitive too.
+            _ => false,
+        }
+    }
+
+    pub fn skip_value_index(&self) -> bool {
+        use http::header;
+
+        match *self {
+            Header::Field { ref name, .. } => matches!(
+                *name,
+                header::AGE
+                    | header::AUTHORIZATION
+                    | header::CONTENT_LENGTH
+                    | header::ETAG
+                    | header::IF_MODIFIED_SINCE
+                    | header::IF_NONE_MATCH
+                    | header::LOCATION
+                    | header::COOKIE
+                    | header::SET_COOKIE
+            ),
+            Header::Path(..) => true,
+            _ => false,
+        }
+    }
+}
+
+// Mostly for tests
+impl From<Header> for Header<Option<HeaderName>> {
+    fn from(src: Header) -> Self {
+        match src {
+            Header::Field { name, value } => Header::Field {
+                name: Some(name),
+                value,
+            },
+            Header::Authority(v) => Header::Authority(v),
+            Header::Method(v) => Header::Method(v),
+            Header::Scheme(v) => Header::Scheme(v),
+            Header::Path(v) => Header::Path(v),
+            Header::Protocol(v) => Header::Protocol(v),
+            Header::Status(v) => Header::Status(v),
+        }
+    }
+}
+
+impl<'a> Name<'a> {
+    pub fn into_entry(self, value: Bytes) -> Result<Header, DecoderError> {
+        match self {
+            Name::Field(name) => Ok(Header::Field {
+                name: name.clone(),
+                value: HeaderValue::from_bytes(&value)?,
+            }),
+            Name::Authority => Ok(Header::Authority(BytesStr::try_from(value)?)),
+            Name::Method => Ok(Header::Method(Method::from_bytes(&value)?)),
+            Name::Scheme => Ok(Header::Scheme(BytesStr::try_from(value)?)),
+            Name::Path => Ok(Header::Path(BytesStr::try_from(value)?)),
+            Name::Protocol => Ok(Header::Protocol(Protocol::try_from(value)?)),
+            Name::Status => {
+                match StatusCode::from_bytes(&value) {
+                    Ok(status) => Ok(Header::Status(status)),
+                    // TODO: better error handling
+                    Err(_) => Err(DecoderError::InvalidStatusCode),
+                }
+            }
+        }
+    }
+
+    pub fn as_slice(&self) -> &[u8] {
+        match *self {
+            Name::Field(ref name) => name.as_ref(),
+            Name::Authority => b":authority",
+            Name::Method => b":method",
+            Name::Scheme => b":scheme",
+            Name::Path => b":path",
+            Name::Protocol => b":protocol",
+            Name::Status => b":status",
+        }
+    }
+}
+
+// ===== impl BytesStr =====
+
+impl BytesStr {
+    pub(crate) const fn from_static(value: &'static str) -> Self {
+        BytesStr(Bytes::from_static(value.as_bytes()))
+    }
+
+    pub(crate) fn from(value: &str) -> Self {
+        BytesStr(Bytes::copy_from_slice(value.as_bytes()))
+    }
+
+    #[doc(hidden)]
+    pub fn try_from(bytes: Bytes) -> Result<Self, std::str::Utf8Error> {
+        std::str::from_utf8(bytes.as_ref())?;
+        Ok(BytesStr(bytes))
+    }
+
+    pub(crate) fn as_str(&self) -> &str {
+        // Safety: check valid utf-8 in constructor
+        unsafe { std::str::from_utf8_unchecked(self.0.as_ref()) }
+    }
+
+    pub(crate) fn into_inner(self) -> Bytes {
+        self.0
+    }
+}
+
+impl std::ops::Deref for BytesStr {
+    type Target = str;
+    fn deref(&self) -> &str {
+        self.as_str()
+    }
+}
+
+impl AsRef<[u8]> for BytesStr {
+    fn as_ref(&self) -> &[u8] {
+        self.0.as_ref()
+    }
+}
+
+impl fmt::Debug for BytesStr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}

vendor/h2/src/hpack/huffman/mod.rs

@@ -0,0 +1,199 @@
+mod table;
+
+use self::table::{DECODE_TABLE, ENCODE_TABLE};
+use crate::hpack::DecoderError;
+
+use bytes::{BufMut, BytesMut};
+
+// Constructed in the generated `table.rs` file
+struct Decoder {
+    state: u8,
+    maybe_eos: bool,
+}
+
+// These flags must match the ones in genhuff.rs
+
+const MAYBE_EOS: u8 = 1;
+const DECODED: u8 = 2;
+const ERROR: u8 = 4;
+
+pub fn decode(src: &[u8], buf: &mut BytesMut) -> Result<BytesMut, DecoderError> {
+    let mut decoder = Decoder::new();
+
+    // Max compression ratio is >= 0.5
+    buf.reserve(src.len() << 1);
+
+    for b in src {
+        if let Some(b) = decoder.decode4(b >> 4)? {
+            buf.put_u8(b);
+        }
+
+        if let Some(b) = decoder.decode4(b & 0xf)? {
+            buf.put_u8(b);
+        }
+    }
+
+    if !decoder.is_final() {
+        return Err(DecoderError::InvalidHuffmanCode);
+    }
+
+    Ok(buf.split())
+}
+
+pub fn encode(src: &[u8], dst: &mut BytesMut) {
+    let mut bits: u64 = 0;
+    let mut bits_left = 40;
+
+    for &b in src {
+        let (nbits, code) = ENCODE_TABLE[b as usize];
+
+        bits |= code << (bits_left - nbits);
+        bits_left -= nbits;
+
+        while bits_left <= 32 {
+            dst.put_u8((bits >> 32) as u8);
+
+            bits <<= 8;
+            bits_left += 8;
+        }
+    }
+
+    if bits_left != 40 {
+        // This writes the EOS token
+        bits |= (1 << bits_left) - 1;
+        dst.put_u8((bits >> 32) as u8);
+    }
+}
+
+impl Decoder {
+    fn new() -> Decoder {
+        Decoder {
+            state: 0,
+            maybe_eos: false,
+        }
+    }
+
+    // Decodes 4 bits
+    fn decode4(&mut self, input: u8) -> Result<Option<u8>, DecoderError> {
+        // (next-state, byte, flags)
+        let (next, byte, flags) = DECODE_TABLE[self.state as usize][input as usize];
+
+        if flags & ERROR == ERROR {
+            // Data followed the EOS marker
+            return Err(DecoderError::InvalidHuffmanCode);
+        }
+
+        let mut ret = None;
+
+        if flags & DECODED == DECODED {
+            ret = Some(byte);
+        }
+
+        self.state = next;
+        self.maybe_eos = flags & MAYBE_EOS == MAYBE_EOS;
+
+        Ok(ret)
+    }
+
+    fn is_final(&self) -> bool {
+        self.state == 0 || self.maybe_eos
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    fn decode(src: &[u8]) -> Result<BytesMut, DecoderError> {
+        let mut buf = BytesMut::new();
+        super::decode(src, &mut buf)
+    }
+
+    #[test]
+    fn decode_single_byte() {
+        assert_eq!("o", decode(&[0b00111111]).unwrap());
+        assert_eq!("0", decode(&[7]).unwrap());
+        assert_eq!("A", decode(&[(0x21 << 2) + 3]).unwrap());
+    }
+
+    #[test]
+    fn single_char_multi_byte() {
+        assert_eq!("#", decode(&[255, 160 + 15]).unwrap());
+        assert_eq!("$", decode(&[255, 200 + 7]).unwrap());
+        assert_eq!("\x0a", decode(&[255, 255, 255, 240 + 3]).unwrap());
+    }
+
+    #[test]
+    fn multi_char() {
+        assert_eq!("!0", decode(&[254, 1]).unwrap());
+        assert_eq!(" !", decode(&[0b01010011, 0b11111000]).unwrap());
+    }
+
+    #[test]
+    fn encode_single_byte() {
+        let mut dst = BytesMut::with_capacity(1);
+
+        encode(b"o", &mut dst);
+        assert_eq!(&dst[..], &[0b00111111]);
+
+        dst.clear();
+        encode(b"0", &mut dst);
+        assert_eq!(&dst[..], &[7]);
+
+        dst.clear();
+        encode(b"A", &mut dst);
+        assert_eq!(&dst[..], &[(0x21 << 2) + 3]);
+    }
+
+    #[test]
+    fn encode_decode_str() {
+        const DATA: &[&str] = &[
+            "hello world",
+            ":method",
+            ":scheme",
+            ":authority",
+            "yahoo.co.jp",
+            "GET",
+            "http",
+            ":path",
+            "/images/top/sp2/cmn/logo-ns-130528.png",
+            "example.com",
+            "hpack-test",
+            "xxxxxxx1",
+            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:16.0) Gecko/20100101 Firefox/16.0",
+            "accept",
+            "Accept",
+            "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
+            "cookie",
+            "B=76j09a189a6h4&b=3&s=0b",
+            "TE",
+            "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi non bibendum libero. \
+             Etiam ultrices lorem ut.",
+        ];
+
+        for s in DATA {
+            let mut dst = BytesMut::with_capacity(s.len());
+
+            encode(s.as_bytes(), &mut dst);
+
+            let decoded = decode(&dst).unwrap();
+
+            assert_eq!(&decoded[..], s.as_bytes());
+        }
+    }
+
+    #[test]
+    fn encode_decode_u8() {
+        const DATA: &[&[u8]] = &[b"\0", b"\0\0\0", b"\0\x01\x02\x03\x04\x05", b"\xFF\xF8"];
+
+        for s in DATA {
+            let mut dst = BytesMut::with_capacity(s.len());
+
+            encode(s, &mut dst);
+
+            let decoded = decode(&dst).unwrap();
+
+            assert_eq!(&decoded[..], &s[..]);
+        }
+    }
+}

vendor/h2/src/hpack/mod.rs

@@ -0,0 +1,12 @@
+mod decoder;
+mod encoder;
+pub(crate) mod header;
+pub(crate) mod huffman;
+mod table;
+
+#[cfg(test)]
+mod test;
+
+pub use self::decoder::{Decoder, DecoderError, NeedMore};
+pub use self::encoder::Encoder;
+pub use self::header::{BytesStr, Header};

vendor/h2/src/hpack/table.rs

@@ -0,0 +1,766 @@
+use super::Header;
+
+use fnv::FnvHasher;
+use http::header;
+use http::method::Method;
+
+use std::collections::VecDeque;
+use std::hash::{Hash, Hasher};
+use std::{cmp, mem};
+
+/// HPACK encoder table
+#[derive(Debug)]
+pub struct Table {
+    mask: usize,
+    indices: Vec<Option<Pos>>,
+    slots: VecDeque<Slot>,
+    inserted: usize,
+    // Size is in bytes
+    size: usize,
+    max_size: usize,
+}
+
+#[derive(Debug)]
+pub enum Index {
+    // The header is already fully indexed
+    Indexed(usize, Header),
+
+    // The name is indexed, but not the value
+    Name(usize, Header),
+
+    // The full header has been inserted into the table.
+    Inserted(usize),
+
+    // Only the value has been inserted (hpack table idx, slots idx)
+    InsertedValue(usize, usize),
+
+    // The header is not indexed by this table
+    NotIndexed(Header),
+}
+
+#[derive(Debug)]
+struct Slot {
+    hash: HashValue,
+    header: Header,
+    next: Option<usize>,
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+struct Pos {
+    index: usize,
+    hash: HashValue,
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+struct HashValue(usize);
+
+const MAX_SIZE: usize = 1 << 16;
+const DYN_OFFSET: usize = 62;
+
+macro_rules! probe_loop {
+    ($probe_var: ident < $len: expr, $body: expr) => {
+        debug_assert!($len > 0);
+        loop {
+            if $probe_var < $len {
+                $body
+                $probe_var += 1;
+            } else {
+                $probe_var = 0;
+            }
+        }
+    };
+}
+
+impl Table {
+    pub fn new(max_size: usize, capacity: usize) -> Table {
+        if capacity == 0 {
+            Table {
+                mask: 0,
+                indices: vec![],
+                slots: VecDeque::new(),
+                inserted: 0,
+                size: 0,
+                max_size,
+            }
+        } else {
+            let capacity = cmp::max(to_raw_capacity(capacity).next_power_of_two(), 8);
+
+            Table {
+                mask: capacity.wrapping_sub(1),
+                indices: vec![None; capacity],
+                slots: VecDeque::with_capacity(usable_capacity(capacity)),
+                inserted: 0,
+                size: 0,
+                max_size,
+            }
+        }
+    }
+
+    #[inline]
+    pub fn capacity(&self) -> usize {
+        usable_capacity(self.indices.len())
+    }
+
+    pub fn max_size(&self) -> usize {
+        self.max_size
+    }
+
+    /// Gets the header stored in the table
+    pub fn resolve<'a>(&'a self, index: &'a Index) -> &'a Header {
+        use self::Index::*;
+
+        match *index {
+            Indexed(_, ref h) => h,
+            Name(_, ref h) => h,
+            Inserted(idx) => &self.slots[idx].header,
+            InsertedValue(_, idx) => &self.slots[idx].header,
+            NotIndexed(ref h) => h,
+        }
+    }
+
+    pub fn resolve_idx(&self, index: &Index) -> usize {
+        use self::Index::*;
+
+        match *index {
+            Indexed(idx, ..) => idx,
+            Name(idx, ..) => idx,
+            Inserted(idx) => idx + DYN_OFFSET,
+            InsertedValue(_name_idx, slot_idx) => slot_idx + DYN_OFFSET,
+            NotIndexed(_) => panic!("cannot resolve index"),
+        }
+    }
+
+    /// Index the header in the HPACK table.
+    pub fn index(&mut self, header: Header) -> Index {
+        // Check the static table
+        let statik = index_static(&header);
+
+        // Don't index certain headers. This logic is borrowed from nghttp2.
+        if header.skip_value_index() {
+            // Right now, if this is true, the header name is always in the
+            // static table. At some point in the future, this might not be true
+            // and this logic will need to be updated.
+            debug_assert!(statik.is_some(), "skip_value_index requires a static name",);
+            return Index::new(statik, header);
+        }
+
+        // If the header is already indexed by the static table, return that
+        if let Some((n, true)) = statik {
+            return Index::Indexed(n, header);
+        }
+
+        // Don't index large headers
+        if header.len() * 4 > self.max_size * 3 {
+            return Index::new(statik, header);
+        }
+
+        self.index_dynamic(header, statik)
+    }
+
+    fn index_dynamic(&mut self, header: Header, statik: Option<(usize, bool)>) -> Index {
+        debug_assert!(self.assert_valid_state("one"));
+
+        if header.len() + self.size < self.max_size || !header.is_sensitive() {
+            // Only grow internal storage if needed
+            self.reserve_one();
+        }
+
+        if self.indices.is_empty() {
+            // If `indices` is not empty, then it is impossible for all
+            // `indices` entries to be `Some`. So, we only need to check for the
+            // empty case.
+            return Index::new(statik, header);
+        }
+
+        let hash = hash_header(&header);
+
+        let desired_pos = desired_pos(self.mask, hash);
+        let mut probe = desired_pos;
+        let mut dist = 0;
+
+        // Start at the ideal position, checking all slots
+        probe_loop!(probe < self.indices.len(), {
+            if let Some(pos) = self.indices[probe] {
+                // The slot is already occupied, but check if it has a lower
+                // displacement.
+                let their_dist = probe_distance(self.mask, pos.hash, probe);
+
+                let slot_idx = pos.index.wrapping_add(self.inserted);
+
+                if their_dist < dist {
+                    // Index robinhood
+                    return self.index_vacant(header, hash, dist, probe, statik);
+                } else if pos.hash == hash && self.slots[slot_idx].header.name() == header.name() {
+                    // Matching name, check values
+                    return self.index_occupied(header, hash, pos.index, statik.map(|(n, _)| n));
+                }
+            } else {
+                return self.index_vacant(header, hash, dist, probe, statik);
+            }
+
+            dist += 1;
+        });
+    }
+
+    fn index_occupied(
+        &mut self,
+        header: Header,
+        hash: HashValue,
+        mut index: usize,
+        statik: Option<usize>,
+    ) -> Index {
+        debug_assert!(self.assert_valid_state("top"));
+
+        // There already is a match for the given header name. Check if a value
+        // matches. The header will also only be inserted if the table is not at
+        // capacity.
+        loop {
+            // Compute the real index into the VecDeque
+            let real_idx = index.wrapping_add(self.inserted);
+
+            if self.slots[real_idx].header.value_eq(&header) {
+                // We have a full match!
+                return Index::Indexed(real_idx + DYN_OFFSET, header);
+            }
+
+            if let Some(next) = self.slots[real_idx].next {
+                index = next;
+                continue;
+            }
+
+            if header.is_sensitive() {
+                // Should we assert this?
+                // debug_assert!(statik.is_none());
+                return Index::Name(real_idx + DYN_OFFSET, header);
+            }
+
+            self.update_size(header.len(), Some(index));
+
+            // Insert the new header
+            self.insert(header, hash);
+
+            // Recompute real_idx as it just changed.
+            let new_real_idx = index.wrapping_add(self.inserted);
+
+            // The previous node in the linked list may have gotten evicted
+            // while making room for this header.
+            if new_real_idx < self.slots.len() {
+                let idx = 0usize.wrapping_sub(self.inserted);
+
+                self.slots[new_real_idx].next = Some(idx);
+            }
+
+            debug_assert!(self.assert_valid_state("bottom"));
+
+            // Even if the previous header was evicted, we can still reference
+            // it when inserting the new one...
+            return if let Some(n) = statik {
+                // If name is in static table, use it instead
+                Index::InsertedValue(n, 0)
+            } else {
+                Index::InsertedValue(real_idx + DYN_OFFSET, 0)
+            };
+        }
+    }
+
+    fn index_vacant(
+        &mut self,
+        header: Header,
+        hash: HashValue,
+        mut dist: usize,
+        mut probe: usize,
+        statik: Option<(usize, bool)>,
+    ) -> Index {
+        if header.is_sensitive() {
+            return Index::new(statik, header);
+        }
+
+        debug_assert!(self.assert_valid_state("top"));
+        debug_assert!(dist == 0 || self.indices[probe.wrapping_sub(1) & self.mask].is_some());
+
+        // Passing in `usize::MAX` for prev_idx since there is no previous
+        // header in this case.
+        if self.update_size(header.len(), None) {
+            while dist != 0 {
+                let back = probe.wrapping_sub(1) & self.mask;
+
+                if let Some(pos) = self.indices[back] {
+                    let their_dist = probe_distance(self.mask, pos.hash, back);
+
+                    if their_dist < (dist - 1) {
+                        probe = back;
+                        dist -= 1;
+                    } else {
+                        break;
+                    }
+                } else {
+                    probe = back;
+                    dist -= 1;
+                }
+            }
+        }
+
+        debug_assert!(self.assert_valid_state("after update"));
+
+        self.insert(header, hash);
+
+        let pos_idx = 0usize.wrapping_sub(self.inserted);
+
+        let prev = mem::replace(
+            &mut self.indices[probe],
+            Some(Pos {
+                index: pos_idx,
+                hash,
+            }),
+        );
+
+        if let Some(mut prev) = prev {
+            // Shift forward
+            let mut probe = probe + 1;
+
+            probe_loop!(probe < self.indices.len(), {
+                let pos = &mut self.indices[probe];
+
+                prev = match mem::replace(pos, Some(prev)) {
+                    Some(p) => p,
+                    None => break,
+                };
+            });
+        }
+
+        debug_assert!(self.assert_valid_state("bottom"));
+
+        if let Some((n, _)) = statik {
+            Index::InsertedValue(n, 0)
+        } else {
+            Index::Inserted(0)
+        }
+    }
+
+    fn insert(&mut self, header: Header, hash: HashValue) {
+        self.inserted = self.inserted.wrapping_add(1);
+
+        self.slots.push_front(Slot {
+            hash,
+            header,
+            next: None,
+        });
+    }
+
+    pub fn resize(&mut self, size: usize) {
+        self.max_size = size;
+
+        if size == 0 {
+            self.size = 0;
+
+            for i in &mut self.indices {
+                *i = None;
+            }
+
+            self.slots.clear();
+            self.inserted = 0;
+        } else {
+            self.converge(None);
+        }
+    }
+
+    fn update_size(&mut self, len: usize, prev_idx: Option<usize>) -> bool {
+        self.size += len;
+        self.converge(prev_idx)
+    }
+
+    fn converge(&mut self, prev_idx: Option<usize>) -> bool {
+        let mut ret = false;
+
+        while self.size > self.max_size {
+            ret = true;
+            self.evict(prev_idx);
+        }
+
+        ret
+    }
+
+    fn evict(&mut self, prev_idx: Option<usize>) {
+        let pos_idx = (self.slots.len() - 1).wrapping_sub(self.inserted);
+
+        debug_assert!(!self.slots.is_empty());
+        debug_assert!(self.assert_valid_state("one"));
+
+        // Remove the header
+        let slot = self.slots.pop_back().unwrap();
+        let mut probe = desired_pos(self.mask, slot.hash);
+
+        // Update the size
+        self.size -= slot.header.len();
+
+        debug_assert_eq!(
+            self.indices
+                .iter()
+                .filter_map(|p| *p)
+                .filter(|p| p.index == pos_idx)
+                .count(),
+            1
+        );
+
+        // Find the associated position
+        probe_loop!(probe < self.indices.len(), {
+            debug_assert!(self.indices[probe].is_some());
+
+            let mut pos = self.indices[probe].unwrap();
+
+            if pos.index == pos_idx {
+                if let Some(idx) = slot.next {
+                    pos.index = idx;
+                    self.indices[probe] = Some(pos);
+                } else if Some(pos.index) == prev_idx {
+                    pos.index = 0usize.wrapping_sub(self.inserted + 1);
+                    self.indices[probe] = Some(pos);
+                } else {
+                    self.indices[probe] = None;
+                    self.remove_phase_two(probe);
+                }
+
+                break;
+            }
+        });
+
+        debug_assert!(self.assert_valid_state("two"));
+    }
+
+    // Shifts all indices that were displaced by the header that has just been
+    // removed.
+    fn remove_phase_two(&mut self, probe: usize) {
+        let mut last_probe = probe;
+        let mut probe = probe + 1;
+
+        probe_loop!(probe < self.indices.len(), {
+            if let Some(pos) = self.indices[probe] {
+                if probe_distance(self.mask, pos.hash, probe) > 0 {
+                    self.indices[last_probe] = self.indices[probe].take();
+                } else {
+                    break;
+                }
+            } else {
+                break;
+            }
+
+            last_probe = probe;
+        });
+
+        debug_assert!(self.assert_valid_state("two"));
+    }
+
+    fn reserve_one(&mut self) {
+        let len = self.slots.len();
+
+        if len == self.capacity() {
+            if len == 0 {
+                let new_raw_cap = 8;
+                self.mask = 8 - 1;
+                self.indices = vec![None; new_raw_cap];
+            } else {
+                let raw_cap = self.indices.len();
+                self.grow(raw_cap << 1);
+            }
+        }
+    }
+
+    #[inline]
+    fn grow(&mut self, new_raw_cap: usize) {
+        // This path can never be reached when handling the first allocation in
+        // the map.
+
+        debug_assert!(self.assert_valid_state("top"));
+
+        // find first ideally placed element -- start of cluster
+        let mut first_ideal = 0;
+
+        for (i, pos) in self.indices.iter().enumerate() {
+            if let Some(pos) = *pos {
+                if 0 == probe_distance(self.mask, pos.hash, i) {
+                    first_ideal = i;
+                    break;
+                }
+            }
+        }
+
+        // visit the entries in an order where we can simply reinsert them
+        // into self.indices without any bucket stealing.
+        let old_indices = mem::replace(&mut self.indices, vec![None; new_raw_cap]);
+        self.mask = new_raw_cap.wrapping_sub(1);
+
+        for &pos in &old_indices[first_ideal..] {
+            self.reinsert_entry_in_order(pos);
+        }
+
+        for &pos in &old_indices[..first_ideal] {
+            self.reinsert_entry_in_order(pos);
+        }
+
+        debug_assert!(self.assert_valid_state("bottom"));
+    }
+
+    fn reinsert_entry_in_order(&mut self, pos: Option<Pos>) {
+        if let Some(pos) = pos {
+            // Find first empty bucket and insert there
+            let mut probe = desired_pos(self.mask, pos.hash);
+
+            probe_loop!(probe < self.indices.len(), {
+                if self.indices[probe].is_none() {
+                    // empty bucket, insert here
+                    self.indices[probe] = Some(pos);
+                    return;
+                }
+
+                debug_assert!({
+                    let them = self.indices[probe].unwrap();
+                    let their_distance = probe_distance(self.mask, them.hash, probe);
+                    let our_distance = probe_distance(self.mask, pos.hash, probe);
+
+                    their_distance >= our_distance
+                });
+            });
+        }
+    }
+
+    #[cfg(not(test))]
+    fn assert_valid_state(&self, _: &'static str) -> bool {
+        true
+    }
+
+    #[cfg(test)]
+    fn assert_valid_state(&self, _msg: &'static str) -> bool {
+        /*
+            // Checks that the internal map structure is valid
+            //
+            // Ensure all hash codes in indices match the associated slot
+            for pos in &self.indices {
+                if let Some(pos) = *pos {
+                    let real_idx = pos.index.wrapping_add(self.inserted);
+
+                    if real_idx.wrapping_add(1) != 0 {
+                        assert!(real_idx < self.slots.len(),
+                                "out of index; real={}; len={}, msg={}",
+                                real_idx, self.slots.len(), msg);
+
+                        assert_eq!(pos.hash, self.slots[real_idx].hash,
+                                   "index hash does not match slot; msg={}", msg);
+                    }
+                }
+            }
+
+            // Every index is only available once
+            for i in 0..self.indices.len() {
+                if self.indices[i].is_none() {
+                    continue;
+                }
+
+                for j in i+1..self.indices.len() {
+                    assert_ne!(self.indices[i], self.indices[j],
+                                "duplicate indices; msg={}", msg);
+                }
+            }
+
+            for (index, slot) in self.slots.iter().enumerate() {
+                let mut indexed = None;
+
+                // First, see if the slot is indexed
+                for (i, pos) in self.indices.iter().enumerate() {
+                    if let Some(pos) = *pos {
+                        let real_idx = pos.index.wrapping_add(self.inserted);
+                        if real_idx == index {
+                            indexed = Some(i);
+                            // Already know that there is no dup, so break
+                            break;
+                        }
+                    }
+                }
+
+                if let Some(actual) = indexed {
+                    // Ensure that it is accessible..
+                    let desired = desired_pos(self.mask, slot.hash);
+                    let mut probe = desired;
+                    let mut dist = 0;
+
+                    probe_loop!(probe < self.indices.len(), {
+                        assert!(self.indices[probe].is_some(),
+                                "unexpected empty slot; probe={}; hash={:?}; msg={}",
+                                probe, slot.hash, msg);
+
+                        let pos = self.indices[probe].unwrap();
+
+                        let their_dist = probe_distance(self.mask, pos.hash, probe);
+                        let real_idx = pos.index.wrapping_add(self.inserted);
+
+                        if real_idx == index {
+                            break;
+                        }
+
+                        assert!(dist <= their_dist,
+                                "could not find entry; actual={}; desired={}" +
+                                "probe={}, dist={}; their_dist={}; index={}; msg={}",
+                                actual, desired, probe, dist, their_dist,
+                                index.wrapping_sub(self.inserted), msg);
+
+                        dist += 1;
+                    });
+                } else {
+                    // There is exactly one next link
+                    let cnt = self.slots.iter().map(|s| s.next)
+                        .filter(|n| *n == Some(index.wrapping_sub(self.inserted)))
+                        .count();
+
+                    assert_eq!(1, cnt, "more than one node pointing here; msg={}", msg);
+                }
+            }
+        */
+
+        // TODO: Ensure linked lists are correct: no cycles, etc...
+
+        true
+    }
+}
+
+#[cfg(test)]
+impl Table {
+    /// Returns the number of headers in the table
+    pub fn len(&self) -> usize {
+        self.slots.len()
+    }
+
+    /// Returns the table size
+    pub fn size(&self) -> usize {
+        self.size
+    }
+}
+
+impl Index {
+    fn new(v: Option<(usize, bool)>, e: Header) -> Index {
+        match v {
+            None => Index::NotIndexed(e),
+            Some((n, true)) => Index::Indexed(n, e),
+            Some((n, false)) => Index::Name(n, e),
+        }
+    }
+}
+
+#[inline]
+fn usable_capacity(cap: usize) -> usize {
+    cap - cap / 4
+}
+
+#[inline]
+fn to_raw_capacity(n: usize) -> usize {
+    n + n / 3
+}
+
+#[inline]
+fn desired_pos(mask: usize, hash: HashValue) -> usize {
+    hash.0 & mask
+}
+
+#[inline]
+fn probe_distance(mask: usize, hash: HashValue, current: usize) -> usize {
+    current.wrapping_sub(desired_pos(mask, hash)) & mask
+}
+
+fn hash_header(header: &Header) -> HashValue {
+    const MASK: u64 = (MAX_SIZE as u64) - 1;
+
+    let mut h = FnvHasher::default();
+    header.name().hash(&mut h);
+    HashValue((h.finish() & MASK) as usize)
+}
+
+/// Checks the static table for the header. If found, returns the index and a
+/// boolean representing if the value matched as well.
+fn index_static(header: &Header) -> Option<(usize, bool)> {
+    match *header {
+        Header::Field {
+            ref name,
+            ref value,
+        } => match *name {
+            header::ACCEPT_CHARSET => Some((15, false)),
+            header::ACCEPT_ENCODING => {
+                if value == "gzip, deflate" {
+                    Some((16, true))
+                } else {
+                    Some((16, false))
+                }
+            }
+            header::ACCEPT_LANGUAGE => Some((17, false)),
+            header::ACCEPT_RANGES => Some((18, false)),
+            header::ACCEPT => Some((19, false)),
+            header::ACCESS_CONTROL_ALLOW_ORIGIN => Some((20, false)),
+            header::AGE => Some((21, false)),
+            header::ALLOW => Some((22, false)),
+            header::AUTHORIZATION => Some((23, false)),
+            header::CACHE_CONTROL => Some((24, false)),
+            header::CONTENT_DISPOSITION => Some((25, false)),
+            header::CONTENT_ENCODING => Some((26, false)),
+            header::CONTENT_LANGUAGE => Some((27, false)),
+            header::CONTENT_LENGTH => Some((28, false)),
+            header::CONTENT_LOCATION => Some((29, false)),
+            header::CONTENT_RANGE => Some((30, false)),
+            header::CONTENT_TYPE => Some((31, false)),
+            header::COOKIE => Some((32, false)),
+            header::DATE => Some((33, false)),
+            header::ETAG => Some((34, false)),
+            header::EXPECT => Some((35, false)),
+            header::EXPIRES => Some((36, false)),
+            header::FROM => Some((37, false)),
+            header::HOST => Some((38, false)),
+            header::IF_MATCH => Some((39, false)),
+            header::IF_MODIFIED_SINCE => Some((40, false)),
+            header::IF_NONE_MATCH => Some((41, false)),
+            header::IF_RANGE => Some((42, false)),
+            header::IF_UNMODIFIED_SINCE => Some((43, false)),
+            header::LAST_MODIFIED => Some((44, false)),
+            header::LINK => Some((45, false)),
+            header::LOCATION => Some((46, false)),
+            header::MAX_FORWARDS => Some((47, false)),
+            header::PROXY_AUTHENTICATE => Some((48, false)),
+            header::PROXY_AUTHORIZATION => Some((49, false)),
+            header::RANGE => Some((50, false)),
+            header::REFERER => Some((51, false)),
+            header::REFRESH => Some((52, false)),
+            header::RETRY_AFTER => Some((53, false)),
+            header::SERVER => Some((54, false)),
+            header::SET_COOKIE => Some((55, false)),
+            header::STRICT_TRANSPORT_SECURITY => Some((56, false)),
+            header::TRANSFER_ENCODING => Some((57, false)),
+            header::USER_AGENT => Some((58, false)),
+            header::VARY => Some((59, false)),
+            header::VIA => Some((60, false)),
+            header::WWW_AUTHENTICATE => Some((61, false)),
+            _ => None,
+        },
+        Header::Authority(_) => Some((1, false)),
+        Header::Method(ref v) => match *v {
+            Method::GET => Some((2, true)),
+            Method::POST => Some((3, true)),
+            _ => Some((2, false)),
+        },
+        Header::Scheme(ref v) => match &**v {
+            "http" => Some((6, true)),
+            "https" => Some((7, true)),
+            _ => Some((6, false)),
+        },
+        Header::Path(ref v) => match &**v {
+            "/" => Some((4, true)),
+            "/index.html" => Some((5, true)),
+            _ => Some((4, false)),
+        },
+        Header::Protocol(..) => None,
+        Header::Status(ref v) => match u16::from(*v) {
+            200 => Some((8, true)),
+            204 => Some((9, true)),
+            206 => Some((10, true)),
+            304 => Some((11, true)),
+            400 => Some((12, true)),
+            404 => Some((13, true)),
+            500 => Some((14, true)),
+            _ => Some((8, false)),
+        },
+    }
+}

vendor/h2/src/hpack/test/fixture.rs

@@ -0,0 +1,615 @@
+use crate::hpack::{Decoder, Encoder, Header};
+
+use bytes::BytesMut;
+use hex::FromHex;
+use serde_json::Value;
+
+use std::fs::File;
+use std::io::prelude::*;
+use std::io::Cursor;
+use std::path::Path;
+use std::str;
+
+fn test_fixture(path: &Path) {
+    let mut file = File::open(path).unwrap();
+    let mut data = String::new();
+    file.read_to_string(&mut data).unwrap();
+
+    let story: Value = serde_json::from_str(&data).unwrap();
+    test_story(story);
+}
+
+fn test_story(story: Value) {
+    let story = story.as_object().unwrap();
+
+    if let Some(cases) = story.get("cases") {
+        let mut cases: Vec<_> = cases
+            .as_array()
+            .unwrap()
+            .iter()
+            .map(|case| {
+                let case = case.as_object().unwrap();
+
+                let size = case
+                    .get("header_table_size")
+                    .map(|v| v.as_u64().unwrap() as usize);
+
+                let wire = case.get("wire").unwrap().as_str().unwrap();
+                let wire: Vec<u8> = FromHex::from_hex(wire.as_bytes()).unwrap();
+
+                let expect: Vec<_> = case
+                    .get("headers")
+                    .unwrap()
+                    .as_array()
+                    .unwrap()
+                    .iter()
+                    .map(|h| {
+                        let h = h.as_object().unwrap();
+                        let (name, val) = h.iter().next().unwrap();
+                        (name.clone(), val.as_str().unwrap().to_string())
+                    })
+                    .collect();
+
+                Case {
+                    seqno: case.get("seqno").unwrap().as_u64().unwrap(),
+                    wire,
+                    expect,
+                    header_table_size: size,
+                }
+            })
+            .collect();
+
+        cases.sort_by_key(|c| c.seqno);
+
+        let mut decoder = Decoder::default();
+
+        // First, check decoding against the fixtures
+        for case in &cases {
+            let mut expect = case.expect.clone();
+
+            if let Some(size) = case.header_table_size {
+                decoder.queue_size_update(size);
+            }
+
+            let mut buf = BytesMut::with_capacity(case.wire.len());
+            buf.extend_from_slice(&case.wire);
+            decoder
+                .decode(&mut Cursor::new(&mut buf), |e| {
+                    let (name, value) = expect.remove(0);
+                    assert_eq!(name, key_str(&e));
+                    assert_eq!(value, value_str(&e));
+                })
+                .unwrap();
+
+            assert_eq!(0, expect.len());
+        }
+
+        let mut encoder = Encoder::default();
+        let mut decoder = Decoder::default();
+
+        // Now, encode the headers
+        for case in &cases {
+            let limit = 64 * 1024;
+            let mut buf = BytesMut::with_capacity(limit);
+
+            if let Some(size) = case.header_table_size {
+                encoder.update_max_size(size);
+                decoder.queue_size_update(size);
+            }
+
+            let mut input: Vec<_> = case
+                .expect
+                .iter()
+                .map(|(name, value)| {
+                    Header::new(name.clone().into(), value.clone().into())
+                        .unwrap()
+                        .into()
+                })
+                .collect();
+
+            encoder.encode(input.clone(), &mut buf);
+
+            decoder
+                .decode(&mut Cursor::new(&mut buf), |e| {
+                    assert_eq!(e, input.remove(0).reify().unwrap());
+                })
+                .unwrap();
+
+            assert_eq!(0, input.len());
+        }
+    }
+}
+
+struct Case {
+    seqno: u64,
+    wire: Vec<u8>,
+    expect: Vec<(String, String)>,
+    header_table_size: Option<usize>,
+}
+
+fn key_str(e: &Header) -> &str {
+    match *e {
+        Header::Field { ref name, .. } => name.as_str(),
+        Header::Authority(..) => ":authority",
+        Header::Method(..) => ":method",
+        Header::Scheme(..) => ":scheme",
+        Header::Path(..) => ":path",
+        Header::Protocol(..) => ":protocol",
+        Header::Status(..) => ":status",
+    }
+}
+
+fn value_str(e: &Header) -> &str {
+    match *e {
+        Header::Field { ref value, .. } => value.to_str().unwrap(),
+        Header::Authority(ref v) => v,
+        Header::Method(ref m) => m.as_str(),
+        Header::Scheme(ref v) => v,
+        Header::Path(ref v) => v,
+        Header::Protocol(ref v) => v.as_str(),
+        Header::Status(ref v) => v.as_str(),
+    }
+}
+
+macro_rules! fixture_mod {
+    ($module:ident => {
+        $(
+            ($fn:ident, $path:expr);
+        )+
+    }) => {
+        mod $module {
+            $(
+                #[test]
+                fn $fn() {
+                    let path = ::std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
+                        .join("fixtures/hpack")
+                        .join($path);
+
+                    super::test_fixture(path.as_ref());
+                }
+            )+
+        }
+    }
+}
+
+fixture_mod!(
+    haskell_http2_linear_huffman => {
+        (story_00, "haskell-http2-linear-huffman/story_00.json");
+        (story_01, "haskell-http2-linear-huffman/story_01.json");
+        (story_02, "haskell-http2-linear-huffman/story_02.json");
+        (story_03, "haskell-http2-linear-huffman/story_03.json");
+        (story_04, "haskell-http2-linear-huffman/story_04.json");
+        (story_05, "haskell-http2-linear-huffman/story_05.json");
+        (story_06, "haskell-http2-linear-huffman/story_06.json");
+        (story_07, "haskell-http2-linear-huffman/story_07.json");
+        (story_08, "haskell-http2-linear-huffman/story_08.json");
+        (story_09, "haskell-http2-linear-huffman/story_09.json");
+        (story_10, "haskell-http2-linear-huffman/story_10.json");
+        (story_11, "haskell-http2-linear-huffman/story_11.json");
+        (story_12, "haskell-http2-linear-huffman/story_12.json");
+        (story_13, "haskell-http2-linear-huffman/story_13.json");
+        (story_14, "haskell-http2-linear-huffman/story_14.json");
+        (story_15, "haskell-http2-linear-huffman/story_15.json");
+        (story_16, "haskell-http2-linear-huffman/story_16.json");
+        (story_17, "haskell-http2-linear-huffman/story_17.json");
+        (story_18, "haskell-http2-linear-huffman/story_18.json");
+        (story_19, "haskell-http2-linear-huffman/story_19.json");
+        (story_20, "haskell-http2-linear-huffman/story_20.json");
+        (story_21, "haskell-http2-linear-huffman/story_21.json");
+        (story_22, "haskell-http2-linear-huffman/story_22.json");
+        (story_23, "haskell-http2-linear-huffman/story_23.json");
+        (story_24, "haskell-http2-linear-huffman/story_24.json");
+        (story_25, "haskell-http2-linear-huffman/story_25.json");
+        (story_26, "haskell-http2-linear-huffman/story_26.json");
+        (story_27, "haskell-http2-linear-huffman/story_27.json");
+        (story_28, "haskell-http2-linear-huffman/story_28.json");
+        (story_29, "haskell-http2-linear-huffman/story_29.json");
+        (story_30, "haskell-http2-linear-huffman/story_30.json");
+        (story_31, "haskell-http2-linear-huffman/story_31.json");
+    }
+);
+
+fixture_mod!(
+    python_hpack => {
+        (story_00, "python-hpack/story_00.json");
+        (story_01, "python-hpack/story_01.json");
+        (story_02, "python-hpack/story_02.json");
+        (story_03, "python-hpack/story_03.json");
+        (story_04, "python-hpack/story_04.json");
+        (story_05, "python-hpack/story_05.json");
+        (story_06, "python-hpack/story_06.json");
+        (story_07, "python-hpack/story_07.json");
+        (story_08, "python-hpack/story_08.json");
+        (story_09, "python-hpack/story_09.json");
+        (story_10, "python-hpack/story_10.json");
+        (story_11, "python-hpack/story_11.json");
+        (story_12, "python-hpack/story_12.json");
+        (story_13, "python-hpack/story_13.json");
+        (story_14, "python-hpack/story_14.json");
+        (story_15, "python-hpack/story_15.json");
+        (story_16, "python-hpack/story_16.json");
+        (story_17, "python-hpack/story_17.json");
+        (story_18, "python-hpack/story_18.json");
+        (story_19, "python-hpack/story_19.json");
+        (story_20, "python-hpack/story_20.json");
+        (story_21, "python-hpack/story_21.json");
+        (story_22, "python-hpack/story_22.json");
+        (story_23, "python-hpack/story_23.json");
+        (story_24, "python-hpack/story_24.json");
+        (story_25, "python-hpack/story_25.json");
+        (story_26, "python-hpack/story_26.json");
+        (story_27, "python-hpack/story_27.json");
+        (story_28, "python-hpack/story_28.json");
+        (story_29, "python-hpack/story_29.json");
+        (story_30, "python-hpack/story_30.json");
+        (story_31, "python-hpack/story_31.json");
+    }
+);
+
+fixture_mod!(
+    nghttp2_16384_4096 => {
+        (story_00, "nghttp2-16384-4096/story_00.json");
+        (story_01, "nghttp2-16384-4096/story_01.json");
+        (story_02, "nghttp2-16384-4096/story_02.json");
+        (story_03, "nghttp2-16384-4096/story_03.json");
+        (story_04, "nghttp2-16384-4096/story_04.json");
+        (story_05, "nghttp2-16384-4096/story_05.json");
+        (story_06, "nghttp2-16384-4096/story_06.json");
+        (story_07, "nghttp2-16384-4096/story_07.json");
+        (story_08, "nghttp2-16384-4096/story_08.json");
+        (story_09, "nghttp2-16384-4096/story_09.json");
+        (story_10, "nghttp2-16384-4096/story_10.json");
+        (story_11, "nghttp2-16384-4096/story_11.json");
+        (story_12, "nghttp2-16384-4096/story_12.json");
+        (story_13, "nghttp2-16384-4096/story_13.json");
+        (story_14, "nghttp2-16384-4096/story_14.json");
+        (story_15, "nghttp2-16384-4096/story_15.json");
+        (story_16, "nghttp2-16384-4096/story_16.json");
+        (story_17, "nghttp2-16384-4096/story_17.json");
+        (story_18, "nghttp2-16384-4096/story_18.json");
+        (story_19, "nghttp2-16384-4096/story_19.json");
+        (story_20, "nghttp2-16384-4096/story_20.json");
+        (story_21, "nghttp2-16384-4096/story_21.json");
+        (story_22, "nghttp2-16384-4096/story_22.json");
+        (story_23, "nghttp2-16384-4096/story_23.json");
+        (story_24, "nghttp2-16384-4096/story_24.json");
+        (story_25, "nghttp2-16384-4096/story_25.json");
+        (story_26, "nghttp2-16384-4096/story_26.json");
+        (story_27, "nghttp2-16384-4096/story_27.json");
+        (story_28, "nghttp2-16384-4096/story_28.json");
+        (story_29, "nghttp2-16384-4096/story_29.json");
+        (story_30, "nghttp2-16384-4096/story_30.json");
+    }
+);
+
+fixture_mod!(
+    node_http2_hpack => {
+        (story_00, "node-http2-hpack/story_00.json");
+        (story_01, "node-http2-hpack/story_01.json");
+        (story_02, "node-http2-hpack/story_02.json");
+        (story_03, "node-http2-hpack/story_03.json");
+        (story_04, "node-http2-hpack/story_04.json");
+        (story_05, "node-http2-hpack/story_05.json");
+        (story_06, "node-http2-hpack/story_06.json");
+        (story_07, "node-http2-hpack/story_07.json");
+        (story_08, "node-http2-hpack/story_08.json");
+        (story_09, "node-http2-hpack/story_09.json");
+        (story_10, "node-http2-hpack/story_10.json");
+        (story_11, "node-http2-hpack/story_11.json");
+        (story_12, "node-http2-hpack/story_12.json");
+        (story_13, "node-http2-hpack/story_13.json");
+        (story_14, "node-http2-hpack/story_14.json");
+        (story_15, "node-http2-hpack/story_15.json");
+        (story_16, "node-http2-hpack/story_16.json");
+        (story_17, "node-http2-hpack/story_17.json");
+        (story_18, "node-http2-hpack/story_18.json");
+        (story_19, "node-http2-hpack/story_19.json");
+        (story_20, "node-http2-hpack/story_20.json");
+        (story_21, "node-http2-hpack/story_21.json");
+        (story_22, "node-http2-hpack/story_22.json");
+        (story_23, "node-http2-hpack/story_23.json");
+        (story_24, "node-http2-hpack/story_24.json");
+        (story_25, "node-http2-hpack/story_25.json");
+        (story_26, "node-http2-hpack/story_26.json");
+        (story_27, "node-http2-hpack/story_27.json");
+        (story_28, "node-http2-hpack/story_28.json");
+        (story_29, "node-http2-hpack/story_29.json");
+        (story_30, "node-http2-hpack/story_30.json");
+        (story_31, "node-http2-hpack/story_31.json");
+    }
+);
+
+fixture_mod!(
+    nghttp2_change_table_size => {
+        (story_00, "nghttp2-change-table-size/story_00.json");
+        (story_01, "nghttp2-change-table-size/story_01.json");
+        (story_02, "nghttp2-change-table-size/story_02.json");
+        (story_03, "nghttp2-change-table-size/story_03.json");
+        (story_04, "nghttp2-change-table-size/story_04.json");
+        (story_05, "nghttp2-change-table-size/story_05.json");
+        (story_06, "nghttp2-change-table-size/story_06.json");
+        (story_07, "nghttp2-change-table-size/story_07.json");
+        (story_08, "nghttp2-change-table-size/story_08.json");
+        (story_09, "nghttp2-change-table-size/story_09.json");
+        (story_10, "nghttp2-change-table-size/story_10.json");
+        (story_11, "nghttp2-change-table-size/story_11.json");
+        (story_12, "nghttp2-change-table-size/story_12.json");
+        (story_13, "nghttp2-change-table-size/story_13.json");
+        (story_14, "nghttp2-change-table-size/story_14.json");
+        (story_15, "nghttp2-change-table-size/story_15.json");
+        (story_16, "nghttp2-change-table-size/story_16.json");
+        (story_17, "nghttp2-change-table-size/story_17.json");
+        (story_18, "nghttp2-change-table-size/story_18.json");
+        (story_19, "nghttp2-change-table-size/story_19.json");
+        (story_20, "nghttp2-change-table-size/story_20.json");
+        (story_21, "nghttp2-change-table-size/story_21.json");
+        (story_22, "nghttp2-change-table-size/story_22.json");
+        (story_23, "nghttp2-change-table-size/story_23.json");
+        (story_24, "nghttp2-change-table-size/story_24.json");
+        (story_25, "nghttp2-change-table-size/story_25.json");
+        (story_26, "nghttp2-change-table-size/story_26.json");
+        (story_27, "nghttp2-change-table-size/story_27.json");
+        (story_28, "nghttp2-change-table-size/story_28.json");
+        (story_29, "nghttp2-change-table-size/story_29.json");
+        (story_30, "nghttp2-change-table-size/story_30.json");
+    }
+);
+
+fixture_mod!(
+    haskell_http2_static_huffman => {
+        (story_00, "haskell-http2-static-huffman/story_00.json");
+        (story_01, "haskell-http2-static-huffman/story_01.json");
+        (story_02, "haskell-http2-static-huffman/story_02.json");
+        (story_03, "haskell-http2-static-huffman/story_03.json");
+        (story_04, "haskell-http2-static-huffman/story_04.json");
+        (story_05, "haskell-http2-static-huffman/story_05.json");
+        (story_06, "haskell-http2-static-huffman/story_06.json");
+        (story_07, "haskell-http2-static-huffman/story_07.json");
+        (story_08, "haskell-http2-static-huffman/story_08.json");
+        (story_09, "haskell-http2-static-huffman/story_09.json");
+        (story_10, "haskell-http2-static-huffman/story_10.json");
+        (story_11, "haskell-http2-static-huffman/story_11.json");
+        (story_12, "haskell-http2-static-huffman/story_12.json");
+        (story_13, "haskell-http2-static-huffman/story_13.json");
+        (story_14, "haskell-http2-static-huffman/story_14.json");
+        (story_15, "haskell-http2-static-huffman/story_15.json");
+        (story_16, "haskell-http2-static-huffman/story_16.json");
+        (story_17, "haskell-http2-static-huffman/story_17.json");
+        (story_18, "haskell-http2-static-huffman/story_18.json");
+        (story_19, "haskell-http2-static-huffman/story_19.json");
+        (story_20, "haskell-http2-static-huffman/story_20.json");
+        (story_21, "haskell-http2-static-huffman/story_21.json");
+        (story_22, "haskell-http2-static-huffman/story_22.json");
+        (story_23, "haskell-http2-static-huffman/story_23.json");
+        (story_24, "haskell-http2-static-huffman/story_24.json");
+        (story_25, "haskell-http2-static-huffman/story_25.json");
+        (story_26, "haskell-http2-static-huffman/story_26.json");
+        (story_27, "haskell-http2-static-huffman/story_27.json");
+        (story_28, "haskell-http2-static-huffman/story_28.json");
+        (story_29, "haskell-http2-static-huffman/story_29.json");
+        (story_30, "haskell-http2-static-huffman/story_30.json");
+        (story_31, "haskell-http2-static-huffman/story_31.json");
+    }
+);
+
+fixture_mod!(
+    haskell_http2_naive_huffman => {
+        (story_00, "haskell-http2-naive-huffman/story_00.json");
+        (story_01, "haskell-http2-naive-huffman/story_01.json");
+        (story_02, "haskell-http2-naive-huffman/story_02.json");
+        (story_03, "haskell-http2-naive-huffman/story_03.json");
+        (story_04, "haskell-http2-naive-huffman/story_04.json");
+        (story_05, "haskell-http2-naive-huffman/story_05.json");
+        (story_06, "haskell-http2-naive-huffman/story_06.json");
+        (story_07, "haskell-http2-naive-huffman/story_07.json");
+        (story_08, "haskell-http2-naive-huffman/story_08.json");
+        (story_09, "haskell-http2-naive-huffman/story_09.json");
+        (story_10, "haskell-http2-naive-huffman/story_10.json");
+        (story_11, "haskell-http2-naive-huffman/story_11.json");
+        (story_12, "haskell-http2-naive-huffman/story_12.json");
+        (story_13, "haskell-http2-naive-huffman/story_13.json");
+        (story_14, "haskell-http2-naive-huffman/story_14.json");
+        (story_15, "haskell-http2-naive-huffman/story_15.json");
+        (story_16, "haskell-http2-naive-huffman/story_16.json");
+        (story_17, "haskell-http2-naive-huffman/story_17.json");
+        (story_18, "haskell-http2-naive-huffman/story_18.json");
+        (story_19, "haskell-http2-naive-huffman/story_19.json");
+        (story_20, "haskell-http2-naive-huffman/story_20.json");
+        (story_21, "haskell-http2-naive-huffman/story_21.json");
+        (story_22, "haskell-http2-naive-huffman/story_22.json");
+        (story_23, "haskell-http2-naive-huffman/story_23.json");
+        (story_24, "haskell-http2-naive-huffman/story_24.json");
+        (story_25, "haskell-http2-naive-huffman/story_25.json");
+        (story_26, "haskell-http2-naive-huffman/story_26.json");
+        (story_27, "haskell-http2-naive-huffman/story_27.json");
+        (story_28, "haskell-http2-naive-huffman/story_28.json");
+        (story_29, "haskell-http2-naive-huffman/story_29.json");
+        (story_30, "haskell-http2-naive-huffman/story_30.json");
+        (story_31, "haskell-http2-naive-huffman/story_31.json");
+    }
+);
+
+fixture_mod!(
+    haskell_http2_naive => {
+        (story_00, "haskell-http2-naive/story_00.json");
+        (story_01, "haskell-http2-naive/story_01.json");
+        (story_02, "haskell-http2-naive/story_02.json");
+        (story_03, "haskell-http2-naive/story_03.json");
+        (story_04, "haskell-http2-naive/story_04.json");
+        (story_05, "haskell-http2-naive/story_05.json");
+        (story_06, "haskell-http2-naive/story_06.json");
+        (story_07, "haskell-http2-naive/story_07.json");
+        (story_08, "haskell-http2-naive/story_08.json");
+        (story_09, "haskell-http2-naive/story_09.json");
+        (story_10, "haskell-http2-naive/story_10.json");
+        (story_11, "haskell-http2-naive/story_11.json");
+        (story_12, "haskell-http2-naive/story_12.json");
+        (story_13, "haskell-http2-naive/story_13.json");
+        (story_14, "haskell-http2-naive/story_14.json");
+        (story_15, "haskell-http2-naive/story_15.json");
+        (story_16, "haskell-http2-naive/story_16.json");
+        (story_17, "haskell-http2-naive/story_17.json");
+        (story_18, "haskell-http2-naive/story_18.json");
+        (story_19, "haskell-http2-naive/story_19.json");
+        (story_20, "haskell-http2-naive/story_20.json");
+        (story_21, "haskell-http2-naive/story_21.json");
+        (story_22, "haskell-http2-naive/story_22.json");
+        (story_23, "haskell-http2-naive/story_23.json");
+        (story_24, "haskell-http2-naive/story_24.json");
+        (story_25, "haskell-http2-naive/story_25.json");
+        (story_26, "haskell-http2-naive/story_26.json");
+        (story_27, "haskell-http2-naive/story_27.json");
+        (story_28, "haskell-http2-naive/story_28.json");
+        (story_29, "haskell-http2-naive/story_29.json");
+        (story_30, "haskell-http2-naive/story_30.json");
+        (story_31, "haskell-http2-naive/story_31.json");
+    }
+);
+
+fixture_mod!(
+    haskell_http2_static => {
+        (story_00, "haskell-http2-static/story_00.json");
+        (story_01, "haskell-http2-static/story_01.json");
+        (story_02, "haskell-http2-static/story_02.json");
+        (story_03, "haskell-http2-static/story_03.json");
+        (story_04, "haskell-http2-static/story_04.json");
+        (story_05, "haskell-http2-static/story_05.json");
+        (story_06, "haskell-http2-static/story_06.json");
+        (story_07, "haskell-http2-static/story_07.json");
+        (story_08, "haskell-http2-static/story_08.json");
+        (story_09, "haskell-http2-static/story_09.json");
+        (story_10, "haskell-http2-static/story_10.json");
+        (story_11, "haskell-http2-static/story_11.json");
+        (story_12, "haskell-http2-static/story_12.json");
+        (story_13, "haskell-http2-static/story_13.json");
+        (story_14, "haskell-http2-static/story_14.json");
+        (story_15, "haskell-http2-static/story_15.json");
+        (story_16, "haskell-http2-static/story_16.json");
+        (story_17, "haskell-http2-static/story_17.json");
+        (story_18, "haskell-http2-static/story_18.json");
+        (story_19, "haskell-http2-static/story_19.json");
+        (story_20, "haskell-http2-static/story_20.json");
+        (story_21, "haskell-http2-static/story_21.json");
+        (story_22, "haskell-http2-static/story_22.json");
+        (story_23, "haskell-http2-static/story_23.json");
+        (story_24, "haskell-http2-static/story_24.json");
+        (story_25, "haskell-http2-static/story_25.json");
+        (story_26, "haskell-http2-static/story_26.json");
+        (story_27, "haskell-http2-static/story_27.json");
+        (story_28, "haskell-http2-static/story_28.json");
+        (story_29, "haskell-http2-static/story_29.json");
+        (story_30, "haskell-http2-static/story_30.json");
+        (story_31, "haskell-http2-static/story_31.json");
+    }
+);
+
+fixture_mod!(
+    nghttp2 => {
+        (story_00, "nghttp2/story_00.json");
+        (story_01, "nghttp2/story_01.json");
+        (story_02, "nghttp2/story_02.json");
+        (story_03, "nghttp2/story_03.json");
+        (story_04, "nghttp2/story_04.json");
+        (story_05, "nghttp2/story_05.json");
+        (story_06, "nghttp2/story_06.json");
+        (story_07, "nghttp2/story_07.json");
+        (story_08, "nghttp2/story_08.json");
+        (story_09, "nghttp2/story_09.json");
+        (story_10, "nghttp2/story_10.json");
+        (story_11, "nghttp2/story_11.json");
+        (story_12, "nghttp2/story_12.json");
+        (story_13, "nghttp2/story_13.json");
+        (story_14, "nghttp2/story_14.json");
+        (story_15, "nghttp2/story_15.json");
+        (story_16, "nghttp2/story_16.json");
+        (story_17, "nghttp2/story_17.json");
+        (story_18, "nghttp2/story_18.json");
+        (story_19, "nghttp2/story_19.json");
+        (story_20, "nghttp2/story_20.json");
+        (story_21, "nghttp2/story_21.json");
+        (story_22, "nghttp2/story_22.json");
+        (story_23, "nghttp2/story_23.json");
+        (story_24, "nghttp2/story_24.json");
+        (story_25, "nghttp2/story_25.json");
+        (story_26, "nghttp2/story_26.json");
+        (story_27, "nghttp2/story_27.json");
+        (story_28, "nghttp2/story_28.json");
+        (story_29, "nghttp2/story_29.json");
+        (story_30, "nghttp2/story_30.json");
+        (story_31, "nghttp2/story_31.json");
+    }
+);
+
+fixture_mod!(
+    haskell_http2_linear => {
+        (story_00, "haskell-http2-linear/story_00.json");
+        (story_01, "haskell-http2-linear/story_01.json");
+        (story_02, "haskell-http2-linear/story_02.json");
+        (story_03, "haskell-http2-linear/story_03.json");
+        (story_04, "haskell-http2-linear/story_04.json");
+        (story_05, "haskell-http2-linear/story_05.json");
+        (story_06, "haskell-http2-linear/story_06.json");
+        (story_07, "haskell-http2-linear/story_07.json");
+        (story_08, "haskell-http2-linear/story_08.json");
+        (story_09, "haskell-http2-linear/story_09.json");
+        (story_10, "haskell-http2-linear/story_10.json");
+        (story_11, "haskell-http2-linear/story_11.json");
+        (story_12, "haskell-http2-linear/story_12.json");
+        (story_13, "haskell-http2-linear/story_13.json");
+        (story_14, "haskell-http2-linear/story_14.json");
+        (story_15, "haskell-http2-linear/story_15.json");
+        (story_16, "haskell-http2-linear/story_16.json");
+        (story_17, "haskell-http2-linear/story_17.json");
+        (story_18, "haskell-http2-linear/story_18.json");
+        (story_19, "haskell-http2-linear/story_19.json");
+        (story_20, "haskell-http2-linear/story_20.json");
+        (story_21, "haskell-http2-linear/story_21.json");
+        (story_22, "haskell-http2-linear/story_22.json");
+        (story_23, "haskell-http2-linear/story_23.json");
+        (story_24, "haskell-http2-linear/story_24.json");
+        (story_25, "haskell-http2-linear/story_25.json");
+        (story_26, "haskell-http2-linear/story_26.json");
+        (story_27, "haskell-http2-linear/story_27.json");
+        (story_28, "haskell-http2-linear/story_28.json");
+        (story_29, "haskell-http2-linear/story_29.json");
+        (story_30, "haskell-http2-linear/story_30.json");
+        (story_31, "haskell-http2-linear/story_31.json");
+    }
+);
+
+fixture_mod!(
+    go_hpack => {
+        (story_00, "go-hpack/story_00.json");
+        (story_01, "go-hpack/story_01.json");
+        (story_02, "go-hpack/story_02.json");
+        (story_03, "go-hpack/story_03.json");
+        (story_04, "go-hpack/story_04.json");
+        (story_05, "go-hpack/story_05.json");
+        (story_06, "go-hpack/story_06.json");
+        (story_07, "go-hpack/story_07.json");
+        (story_08, "go-hpack/story_08.json");
+        (story_09, "go-hpack/story_09.json");
+        (story_10, "go-hpack/story_10.json");
+        (story_11, "go-hpack/story_11.json");
+        (story_12, "go-hpack/story_12.json");
+        (story_13, "go-hpack/story_13.json");
+        (story_14, "go-hpack/story_14.json");
+        (story_15, "go-hpack/story_15.json");
+        (story_16, "go-hpack/story_16.json");
+        (story_17, "go-hpack/story_17.json");
+        (story_18, "go-hpack/story_18.json");
+        (story_19, "go-hpack/story_19.json");
+        (story_20, "go-hpack/story_20.json");
+        (story_21, "go-hpack/story_21.json");
+        (story_22, "go-hpack/story_22.json");
+        (story_23, "go-hpack/story_23.json");
+        (story_24, "go-hpack/story_24.json");
+        (story_25, "go-hpack/story_25.json");
+        (story_26, "go-hpack/story_26.json");
+        (story_27, "go-hpack/story_27.json");
+        (story_28, "go-hpack/story_28.json");
+        (story_29, "go-hpack/story_29.json");
+        (story_30, "go-hpack/story_30.json");
+        (story_31, "go-hpack/story_31.json");
+    }
+);

vendor/h2/src/hpack/test/fuzz.rs

@@ -0,0 +1,365 @@
+use crate::hpack::{Decoder, Encoder, Header};
+
+use http::header::{HeaderName, HeaderValue};
+
+use bytes::BytesMut;
+use quickcheck::{Arbitrary, Gen, QuickCheck, TestResult};
+use rand::distributions::Slice;
+use rand::rngs::StdRng;
+use rand::{thread_rng, Rng, SeedableRng};
+
+use std::io::Cursor;
+
+const MAX_CHUNK: usize = 2 * 1024;
+
+#[test]
+fn hpack_fuzz() {
+    let _ = env_logger::try_init();
+    fn prop(fuzz: FuzzHpack) -> TestResult {
+        fuzz.run();
+        TestResult::from_bool(true)
+    }
+
+    QuickCheck::new()
+        .tests(100)
+        .quickcheck(prop as fn(FuzzHpack) -> TestResult)
+}
+
+/*
+// If wanting to test with a specific feed, uncomment and fill in the seed.
+#[test]
+fn hpack_fuzz_seeded() {
+    let _ = env_logger::try_init();
+    let seed = [/* fill me in*/];
+    FuzzHpack::new(seed).run();
+}
+*/
+
+#[derive(Debug, Clone)]
+struct FuzzHpack {
+    // The set of headers to encode / decode
+    frames: Vec<HeaderFrame>,
+}
+
+#[derive(Debug, Clone)]
+struct HeaderFrame {
+    resizes: Vec<usize>,
+    headers: Vec<Header<Option<HeaderName>>>,
+}
+
+impl FuzzHpack {
+    fn new(seed: [u8; 32]) -> FuzzHpack {
+        // Seed the RNG
+        let mut rng = StdRng::from_seed(seed);
+
+        // Generates a bunch of source headers
+        let mut source: Vec<Header<Option<HeaderName>>> = vec![];
+
+        for _ in 0..2000 {
+            source.push(gen_header(&mut rng));
+        }
+
+        // Actual test run headers
+        let num: usize = rng.gen_range(40..500);
+
+        let mut frames: Vec<HeaderFrame> = vec![];
+        let mut added = 0;
+
+        let skew: i32 = rng.gen_range(1..5);
+
+        // Rough number of headers to add
+        while added < num {
+            let mut frame = HeaderFrame {
+                resizes: vec![],
+                headers: vec![],
+            };
+
+            match rng.gen_range(0..20) {
+                0 => {
+                    // Two resizes
+                    let high = rng.gen_range(128..MAX_CHUNK * 2);
+                    let low = rng.gen_range(0..high);
+
+                    frame.resizes.extend([low, high]);
+                }
+                1..=3 => {
+                    frame.resizes.push(rng.gen_range(128..MAX_CHUNK * 2));
+                }
+                _ => {}
+            }
+
+            let mut is_name_required = true;
+
+            for _ in 0..rng.gen_range(1..(num - added) + 1) {
+                let x: f64 = rng.gen_range(0.0..1.0);
+                let x = x.powi(skew);
+
+                let i = (x * source.len() as f64) as usize;
+
+                let header = &source[i];
+                match header {
+                    Header::Field { name: None, .. } => {
+                        if is_name_required {
+                            continue;
+                        }
+                    }
+                    Header::Field { .. } => {
+                        is_name_required = false;
+                    }
+                    _ => {
+                        // pseudos can't be followed by a header with no name
+                        is_name_required = true;
+                    }
+                }
+
+                frame.headers.push(header.clone());
+
+                added += 1;
+            }
+
+            frames.push(frame);
+        }
+
+        FuzzHpack { frames }
+    }
+
+    fn run(self) {
+        let frames = self.frames;
+        let mut expect = vec![];
+
+        let mut encoder = Encoder::default();
+        let mut decoder = Decoder::default();
+
+        for frame in frames {
+            // build "expected" frames, such that decoding headers always
+            // includes a name
+            let mut prev_name = None;
+            for header in &frame.headers {
+                match header.clone().reify() {
+                    Ok(h) => {
+                        prev_name = match h {
+                            Header::Field { ref name, .. } => Some(name.clone()),
+                            _ => None,
+                        };
+                        expect.push(h);
+                    }
+                    Err(value) => {
+                        expect.push(Header::Field {
+                            name: prev_name.as_ref().cloned().expect("previous header name"),
+                            value,
+                        });
+                    }
+                }
+            }
+
+            let mut buf = BytesMut::new();
+
+            if let Some(max) = frame.resizes.iter().max() {
+                decoder.queue_size_update(*max);
+            }
+
+            // Apply resizes
+            for resize in &frame.resizes {
+                encoder.update_max_size(*resize);
+            }
+
+            encoder.encode(frame.headers, &mut buf);
+
+            // Decode the chunk!
+            decoder
+                .decode(&mut Cursor::new(&mut buf), |h| {
+                    let e = expect.remove(0);
+                    assert_eq!(h, e);
+                })
+                .expect("full decode");
+        }
+
+        assert_eq!(0, expect.len());
+    }
+}
+
+impl Arbitrary for FuzzHpack {
+    fn arbitrary(_: &mut Gen) -> Self {
+        FuzzHpack::new(thread_rng().gen())
+    }
+}
+
+fn gen_header(g: &mut StdRng) -> Header<Option<HeaderName>> {
+    use http::{Method, StatusCode};
+
+    if g.gen_ratio(1, 10) {
+        match g.gen_range(0u32..5) {
+            0 => {
+                let value = gen_string(g, 4, 20);
+                Header::Authority(to_shared(value))
+            }
+            1 => {
+                let method = match g.gen_range(0u32..6) {
+                    0 => Method::GET,
+                    1 => Method::POST,
+                    2 => Method::PUT,
+                    3 => Method::PATCH,
+                    4 => Method::DELETE,
+                    5 => {
+                        let n: usize = g.gen_range(3..7);
+                        let bytes: Vec<u8> = (0..n)
+                            .map(|_| *g.sample(Slice::new(b"ABCDEFGHIJKLMNOPQRSTUVWXYZ").unwrap()))
+                            .collect();
+
+                        Method::from_bytes(&bytes).unwrap()
+                    }
+                    _ => unreachable!(),
+                };
+
+                Header::Method(method)
+            }
+            2 => {
+                let value = match g.gen_range(0u32..2) {
+                    0 => "http",
+                    1 => "https",
+                    _ => unreachable!(),
+                };
+
+                Header::Scheme(to_shared(value.to_string()))
+            }
+            3 => {
+                let value = match g.gen_range(0u32..100) {
+                    0 => "/".to_string(),
+                    1 => "/index.html".to_string(),
+                    _ => gen_string(g, 2, 20),
+                };
+
+                Header::Path(to_shared(value))
+            }
+            4 => {
+                let status = (g.gen::<u16>() % 500) + 100;
+
+                Header::Status(StatusCode::from_u16(status).unwrap())
+            }
+            _ => unreachable!(),
+        }
+    } else {
+        let name = if g.gen_ratio(1, 10) {
+            None
+        } else {
+            Some(gen_header_name(g))
+        };
+        let mut value = gen_header_value(g);
+
+        if g.gen_ratio(1, 30) {
+            value.set_sensitive(true);
+        }
+
+        Header::Field { name, value }
+    }
+}
+
+fn gen_header_name(g: &mut StdRng) -> HeaderName {
+    use http::header;
+
+    if g.gen_ratio(1, 2) {
+        g.sample(
+            Slice::new(&[
+                header::ACCEPT,
+                header::ACCEPT_CHARSET,
+                header::ACCEPT_ENCODING,
+                header::ACCEPT_LANGUAGE,
+                header::ACCEPT_RANGES,
+                header::ACCESS_CONTROL_ALLOW_CREDENTIALS,
+                header::ACCESS_CONTROL_ALLOW_HEADERS,
+                header::ACCESS_CONTROL_ALLOW_METHODS,
+                header::ACCESS_CONTROL_ALLOW_ORIGIN,
+                header::ACCESS_CONTROL_EXPOSE_HEADERS,
+                header::ACCESS_CONTROL_MAX_AGE,
+                header::ACCESS_CONTROL_REQUEST_HEADERS,
+                header::ACCESS_CONTROL_REQUEST_METHOD,
+                header::AGE,
+                header::ALLOW,
+                header::ALT_SVC,
+                header::AUTHORIZATION,
+                header::CACHE_CONTROL,
+                header::CONNECTION,
+                header::CONTENT_DISPOSITION,
+                header::CONTENT_ENCODING,
+                header::CONTENT_LANGUAGE,
+                header::CONTENT_LENGTH,
+                header::CONTENT_LOCATION,
+                header::CONTENT_RANGE,
+                header::CONTENT_SECURITY_POLICY,
+                header::CONTENT_SECURITY_POLICY_REPORT_ONLY,
+                header::CONTENT_TYPE,
+                header::COOKIE,
+                header::DNT,
+                header::DATE,
+                header::ETAG,
+                header::EXPECT,
+                header::EXPIRES,
+                header::FORWARDED,
+                header::FROM,
+                header::HOST,
+                header::IF_MATCH,
+                header::IF_MODIFIED_SINCE,
+                header::IF_NONE_MATCH,
+                header::IF_RANGE,
+                header::IF_UNMODIFIED_SINCE,
+                header::LAST_MODIFIED,
+                header::LINK,
+                header::LOCATION,
+                header::MAX_FORWARDS,
+                header::ORIGIN,
+                header::PRAGMA,
+                header::PROXY_AUTHENTICATE,
+                header::PROXY_AUTHORIZATION,
+                header::PUBLIC_KEY_PINS,
+                header::PUBLIC_KEY_PINS_REPORT_ONLY,
+                header::RANGE,
+                header::REFERER,
+                header::REFERRER_POLICY,
+                header::REFRESH,
+                header::RETRY_AFTER,
+                header::SERVER,
+                header::SET_COOKIE,
+                header::STRICT_TRANSPORT_SECURITY,
+                header::TE,
+                header::TRAILER,
+                header::TRANSFER_ENCODING,
+                header::USER_AGENT,
+                header::UPGRADE,
+                header::UPGRADE_INSECURE_REQUESTS,
+                header::VARY,
+                header::VIA,
+                header::WARNING,
+                header::WWW_AUTHENTICATE,
+                header::X_CONTENT_TYPE_OPTIONS,
+                header::X_DNS_PREFETCH_CONTROL,
+                header::X_FRAME_OPTIONS,
+                header::X_XSS_PROTECTION,
+            ])
+            .unwrap(),
+        )
+        .clone()
+    } else {
+        let value = gen_string(g, 1, 25);
+        HeaderName::from_bytes(value.as_bytes()).unwrap()
+    }
+}
+
+fn gen_header_value(g: &mut StdRng) -> HeaderValue {
+    let value = gen_string(g, 0, 70);
+    HeaderValue::from_bytes(value.as_bytes()).unwrap()
+}
+
+fn gen_string(g: &mut StdRng, min: usize, max: usize) -> String {
+    let bytes: Vec<_> = (min..max)
+        .map(|_| {
+            // Chars to pick from
+            *g.sample(Slice::new(b"ABCDEFGHIJKLMNOPQRSTUVabcdefghilpqrstuvwxyz----").unwrap())
+        })
+        .collect();
+
+    String::from_utf8(bytes).unwrap()
+}
+
+fn to_shared(src: String) -> crate::hpack::BytesStr {
+    crate::hpack::BytesStr::from(src.as_str())
+}

vendor/h2/src/hpack/test/mod.rs

@@ -0,0 +1,2 @@
+mod fixture;
+mod fuzz;

vendor/h2/src/lib.rs

@@ -0,0 +1,162 @@
+//! An asynchronous, HTTP/2 server and client implementation.
+//!
+//! This library implements the [HTTP/2] specification. The implementation is
+//! asynchronous, using [futures] as the basis for the API. The implementation
+//! is also decoupled from TCP or TLS details. The user must handle ALPN and
+//! HTTP/1.1 upgrades themselves.
+//!
+//! # Getting started
+//!
+//! Add the following to your `Cargo.toml` file:
+//!
+//! ```toml
+//! [dependencies]
+//! h2 = "0.4"
+//! ```
+//!
+//! # Layout
+//!
+//! The crate is split into [`client`] and [`server`] modules. Types that are
+//! common to both clients and servers are located at the root of the crate.
+//!
+//! See module level documentation for more details on how to use `h2`.
+//!
+//! # Handshake
+//!
+//! Both the client and the server require a connection to already be in a state
+//! ready to start the HTTP/2 handshake. This library does not provide
+//! facilities to do this.
+//!
+//! There are three ways to reach an appropriate state to start the HTTP/2
+//! handshake.
+//!
+//! * Opening an HTTP/1.1 connection and performing an [upgrade].
+//! * Opening a connection with TLS and use ALPN to negotiate the protocol.
+//! * Open a connection with prior knowledge, i.e. both the client and the
+//!   server assume that the connection is immediately ready to start the
+//!   HTTP/2 handshake once opened.
+//!
+//! Once the connection is ready to start the HTTP/2 handshake, it can be
+//! passed to [`server::handshake`] or [`client::handshake`]. At this point, the
+//! library will start the handshake process, which consists of:
+//!
+//! * The client sends the connection preface (a predefined sequence of 24
+//!   octets).
+//! * Both the client and the server sending a SETTINGS frame.
+//!
+//! See the [Starting HTTP/2] in the specification for more details.
+//!
+//! # Flow control
+//!
+//! [Flow control] is a fundamental feature of HTTP/2. The `h2` library
+//! exposes flow control to the user.
+//!
+//! An HTTP/2 client or server may not send unlimited data to the peer. When a
+//! stream is initiated, both the client and the server are provided with an
+//! initial window size for that stream.  A window size is the number of bytes
+//! the endpoint can send to the peer. At any point in time, the peer may
+//! increase this window size by sending a `WINDOW_UPDATE` frame. Once a client
+//! or server has sent data filling the window for a stream, no further data may
+//! be sent on that stream until the peer increases the window.
+//!
+//! There is also a **connection level** window governing data sent across all
+//! streams.
+//!
+//! Managing flow control for inbound data is done through [`FlowControl`].
+//! Managing flow control for outbound data is done through [`SendStream`]. See
+//! the struct level documentation for those two types for more details.
+//!
+//! [HTTP/2]: https://http2.github.io/
+//! [futures]: https://docs.rs/futures/
+//! [`client`]: client/index.html
+//! [`server`]: server/index.html
+//! [Flow control]: http://httpwg.org/specs/rfc7540.html#FlowControl
+//! [`FlowControl`]: struct.FlowControl.html
+//! [`SendStream`]: struct.SendStream.html
+//! [Starting HTTP/2]: http://httpwg.org/specs/rfc7540.html#starting
+//! [upgrade]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Protocol_upgrade_mechanism
+//! [`server::handshake`]: server/fn.handshake.html
+//! [`client::handshake`]: client/fn.handshake.html
+
+#![deny(
+    missing_debug_implementations,
+    missing_docs,
+    clippy::missing_safety_doc,
+    clippy::undocumented_unsafe_blocks
+)]
+#![allow(clippy::type_complexity, clippy::manual_range_contains)]
+#![cfg_attr(test, deny(warnings))]
+
+macro_rules! proto_err {
+    (conn: $($msg:tt)+) => {
+        tracing::debug!("connection error PROTOCOL_ERROR -- {};", format_args!($($msg)+))
+    };
+    (stream: $($msg:tt)+) => {
+        tracing::debug!("stream error PROTOCOL_ERROR -- {};", format_args!($($msg)+))
+    };
+}
+
+macro_rules! ready {
+    ($e:expr) => {
+        match $e {
+            ::std::task::Poll::Ready(r) => r,
+            ::std::task::Poll::Pending => return ::std::task::Poll::Pending,
+        }
+    };
+}
+
+#[cfg_attr(feature = "unstable", allow(missing_docs))]
+mod codec;
+mod error;
+mod hpack;
+
+#[cfg(not(feature = "unstable"))]
+mod proto;
+
+#[cfg(feature = "unstable")]
+#[allow(missing_docs)]
+pub mod proto;
+
+#[cfg(not(feature = "unstable"))]
+mod frame;
+
+#[cfg(feature = "unstable")]
+#[allow(missing_docs)]
+pub mod frame;
+
+pub mod client;
+pub mod ext;
+pub mod server;
+mod share;
+
+#[cfg(fuzzing)]
+#[cfg_attr(feature = "unstable", allow(missing_docs))]
+pub mod fuzz_bridge;
+
+pub use crate::error::{Error, Reason};
+pub use crate::share::{FlowControl, Ping, PingPong, Pong, RecvStream, SendStream, StreamId};
+
+#[cfg(feature = "unstable")]
+pub use codec::{Codec, SendError, UserError};
+
+use std::future::Future;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+/// Creates a future from a function that returns `Poll`.
+fn poll_fn<T, F: FnMut(&mut Context<'_>) -> T>(f: F) -> PollFn<F> {
+    PollFn(f)
+}
+
+/// The future created by `poll_fn`.
+struct PollFn<F>(F);
+
+impl<F> Unpin for PollFn<F> {}
+
+impl<T, F: FnMut(&mut Context<'_>) -> Poll<T>> Future for PollFn<F> {
+    type Output = T;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        (self.0)(cx)
+    }
+}

vendor/h2/src/proto/connection.rs

@@ -0,0 +1,635 @@
+use crate::codec::UserError;
+use crate::frame::{Reason, StreamId};
+use crate::{client, server};
+
+use crate::frame::DEFAULT_INITIAL_WINDOW_SIZE;
+use crate::proto::*;
+
+use bytes::Bytes;
+use futures_core::Stream;
+use std::io;
+use std::marker::PhantomData;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use std::time::Duration;
+use tokio::io::AsyncRead;
+
+/// An H2 connection
+#[derive(Debug)]
+pub(crate) struct Connection<T, P, B: Buf = Bytes>
+where
+    P: Peer,
+{
+    /// Read / write frame values
+    codec: Codec<T, Prioritized<B>>,
+
+    inner: ConnectionInner<P, B>,
+}
+
+// Extracted part of `Connection` which does not depend on `T`. Reduces the amount of duplicated
+// method instantiations.
+#[derive(Debug)]
+struct ConnectionInner<P, B: Buf = Bytes>
+where
+    P: Peer,
+{
+    /// Tracks the connection level state transitions.
+    state: State,
+
+    /// An error to report back once complete.
+    ///
+    /// This exists separately from State in order to support
+    /// graceful shutdown.
+    error: Option<frame::GoAway>,
+
+    /// Pending GOAWAY frames to write.
+    go_away: GoAway,
+
+    /// Ping/pong handler
+    ping_pong: PingPong,
+
+    /// Connection settings
+    settings: Settings,
+
+    /// Stream state handler
+    streams: Streams<B, P>,
+
+    /// A `tracing` span tracking the lifetime of the connection.
+    span: tracing::Span,
+
+    /// Client or server
+    _phantom: PhantomData<P>,
+}
+
+struct DynConnection<'a, B: Buf = Bytes> {
+    state: &'a mut State,
+
+    go_away: &'a mut GoAway,
+
+    streams: DynStreams<'a, B>,
+
+    error: &'a mut Option<frame::GoAway>,
+
+    ping_pong: &'a mut PingPong,
+}
+
+#[derive(Debug, Clone)]
+pub(crate) struct Config {
+    pub next_stream_id: StreamId,
+    pub initial_max_send_streams: usize,
+    pub max_send_buffer_size: usize,
+    pub reset_stream_duration: Duration,
+    pub reset_stream_max: usize,
+    pub remote_reset_stream_max: usize,
+    pub local_error_reset_streams_max: Option<usize>,
+    pub settings: frame::Settings,
+}
+
+#[derive(Debug)]
+enum State {
+    /// Currently open in a sane state
+    Open,
+
+    /// The codec must be flushed
+    Closing(Reason, Initiator),
+
+    /// In a closed state
+    Closed(Reason, Initiator),
+}
+
+impl<T, P, B> Connection<T, P, B>
+where
+    T: AsyncRead + AsyncWrite + Unpin,
+    P: Peer,
+    B: Buf,
+{
+    pub fn new(codec: Codec<T, Prioritized<B>>, config: Config) -> Connection<T, P, B> {
+        fn streams_config(config: &Config) -> streams::Config {
+            streams::Config {
+                initial_max_send_streams: config.initial_max_send_streams,
+                local_max_buffer_size: config.max_send_buffer_size,
+                local_next_stream_id: config.next_stream_id,
+                local_push_enabled: config.settings.is_push_enabled().unwrap_or(true),
+                extended_connect_protocol_enabled: config
+                    .settings
+                    .is_extended_connect_protocol_enabled()
+                    .unwrap_or(false),
+                local_reset_duration: config.reset_stream_duration,
+                local_reset_max: config.reset_stream_max,
+                remote_reset_max: config.remote_reset_stream_max,
+                remote_init_window_sz: DEFAULT_INITIAL_WINDOW_SIZE,
+                remote_max_initiated: config
+                    .settings
+                    .max_concurrent_streams()
+                    .map(|max| max as usize),
+                local_max_error_reset_streams: config.local_error_reset_streams_max,
+            }
+        }
+        let streams = Streams::new(streams_config(&config));
+        let span = tracing::debug_span!(parent: None, "Connection", peer = %P::NAME);
+        span.follows_from(tracing::Span::current());
+        Connection {
+            codec,
+            inner: ConnectionInner {
+                state: State::Open,
+                error: None,
+                go_away: GoAway::new(),
+                ping_pong: PingPong::new(),
+                settings: Settings::new(config.settings),
+                streams,
+                span,
+                _phantom: PhantomData,
+            },
+        }
+    }
+
+    /// connection flow control
+    pub(crate) fn set_target_window_size(&mut self, size: WindowSize) {
+        let _res = self.inner.streams.set_target_connection_window_size(size);
+        // TODO: proper error handling
+        debug_assert!(_res.is_ok());
+    }
+
+    /// Send a new SETTINGS frame with an updated initial window size.
+    pub(crate) fn set_initial_window_size(&mut self, size: WindowSize) -> Result<(), UserError> {
+        let mut settings = frame::Settings::default();
+        settings.set_initial_window_size(Some(size));
+        self.inner.settings.send_settings(settings)
+    }
+
+    /// Send a new SETTINGS frame with extended CONNECT protocol enabled.
+    pub(crate) fn set_enable_connect_protocol(&mut self) -> Result<(), UserError> {
+        let mut settings = frame::Settings::default();
+        settings.set_enable_connect_protocol(Some(1));
+        self.inner.settings.send_settings(settings)
+    }
+
+    /// Returns the maximum number of concurrent streams that may be initiated
+    /// by this peer.
+    pub(crate) fn max_send_streams(&self) -> usize {
+        self.inner.streams.max_send_streams()
+    }
+
+    /// Returns the maximum number of concurrent streams that may be initiated
+    /// by the remote peer.
+    pub(crate) fn max_recv_streams(&self) -> usize {
+        self.inner.streams.max_recv_streams()
+    }
+
+    #[cfg(feature = "unstable")]
+    pub fn num_wired_streams(&self) -> usize {
+        self.inner.streams.num_wired_streams()
+    }
+
+    /// Returns `Ready` when the connection is ready to receive a frame.
+    ///
+    /// Returns `Error` as this may raise errors that are caused by delayed
+    /// processing of received frames.
+    fn poll_ready(&mut self, cx: &mut Context) -> Poll<Result<(), Error>> {
+        let _e = self.inner.span.enter();
+        let span = tracing::trace_span!("poll_ready");
+        let _e = span.enter();
+        // The order of these calls don't really matter too much
+        ready!(self.inner.ping_pong.send_pending_pong(cx, &mut self.codec))?;
+        ready!(self.inner.ping_pong.send_pending_ping(cx, &mut self.codec))?;
+        ready!(self
+            .inner
+            .settings
+            .poll_send(cx, &mut self.codec, &mut self.inner.streams))?;
+        ready!(self.inner.streams.send_pending_refusal(cx, &mut self.codec))?;
+
+        Poll::Ready(Ok(()))
+    }
+
+    /// Send any pending GOAWAY frames.
+    ///
+    /// This will return `Some(reason)` if the connection should be closed
+    /// afterwards. If this is a graceful shutdown, this returns `None`.
+    fn poll_go_away(&mut self, cx: &mut Context) -> Poll<Option<io::Result<Reason>>> {
+        self.inner.go_away.send_pending_go_away(cx, &mut self.codec)
+    }
+
+    pub fn go_away_from_user(&mut self, e: Reason) {
+        self.inner.as_dyn().go_away_from_user(e)
+    }
+
+    fn take_error(&mut self, ours: Reason, initiator: Initiator) -> Result<(), Error> {
+        let (debug_data, theirs) = self
+            .inner
+            .error
+            .take()
+            .as_ref()
+            .map_or((Bytes::new(), Reason::NO_ERROR), |frame| {
+                (frame.debug_data().clone(), frame.reason())
+            });
+
+        match (ours, theirs) {
+            (Reason::NO_ERROR, Reason::NO_ERROR) => Ok(()),
+            (ours, Reason::NO_ERROR) => Err(Error::GoAway(Bytes::new(), ours, initiator)),
+            // If both sides reported an error, give their
+            // error back to th user. We assume our error
+            // was a consequence of their error, and less
+            // important.
+            (_, theirs) => Err(Error::remote_go_away(debug_data, theirs)),
+        }
+    }
+
+    /// Closes the connection by transitioning to a GOAWAY state
+    /// iff there are no streams or references
+    pub fn maybe_close_connection_if_no_streams(&mut self) {
+        // If we poll() and realize that there are no streams or references
+        // then we can close the connection by transitioning to GOAWAY
+        if !self.inner.streams.has_streams_or_other_references() {
+            self.inner.as_dyn().go_away_now(Reason::NO_ERROR);
+        }
+    }
+
+    /// Checks if there are any streams
+    pub fn has_streams(&self) -> bool {
+        self.inner.streams.has_streams()
+    }
+
+    /// Checks if there are any streams or references left
+    pub fn has_streams_or_other_references(&self) -> bool {
+        // If we poll() and realize that there are no streams or references
+        // then we can close the connection by transitioning to GOAWAY
+        self.inner.streams.has_streams_or_other_references()
+    }
+
+    pub(crate) fn take_user_pings(&mut self) -> Option<UserPings> {
+        self.inner.ping_pong.take_user_pings()
+    }
+
+    /// Advances the internal state of the connection.
+    pub fn poll(&mut self, cx: &mut Context) -> Poll<Result<(), Error>> {
+        // XXX(eliza): cloning the span is unfortunately necessary here in
+        // order to placate the borrow checker — `self` is mutably borrowed by
+        // `poll2`, which means that we can't borrow `self.span` to enter it.
+        // The clone is just an atomic ref bump.
+        let span = self.inner.span.clone();
+        let _e = span.enter();
+        let span = tracing::trace_span!("poll");
+        let _e = span.enter();
+
+        loop {
+            tracing::trace!(connection.state = ?self.inner.state);
+            // TODO: probably clean up this glob of code
+            match self.inner.state {
+                // When open, continue to poll a frame
+                State::Open => {
+                    let result = match self.poll2(cx) {
+                        Poll::Ready(result) => result,
+                        // The connection is not ready to make progress
+                        Poll::Pending => {
+                            // Ensure all window updates have been sent.
+                            //
+                            // This will also handle flushing `self.codec`
+                            ready!(self.inner.streams.poll_complete(cx, &mut self.codec))?;
+
+                            if (self.inner.error.is_some()
+                                || self.inner.go_away.should_close_on_idle())
+                                && !self.inner.streams.has_streams()
+                            {
+                                self.inner.as_dyn().go_away_now(Reason::NO_ERROR);
+                                continue;
+                            }
+
+                            return Poll::Pending;
+                        }
+                    };
+
+                    self.inner.as_dyn().handle_poll2_result(result)?
+                }
+                State::Closing(reason, initiator) => {
+                    tracing::trace!("connection closing after flush");
+                    // Flush/shutdown the codec
+                    ready!(self.codec.shutdown(cx))?;
+
+                    // Transition the state to error
+                    self.inner.state = State::Closed(reason, initiator);
+                }
+                State::Closed(reason, initiator) => {
+                    return Poll::Ready(self.take_error(reason, initiator));
+                }
+            }
+        }
+    }
+
+    fn poll2(&mut self, cx: &mut Context) -> Poll<Result<(), Error>> {
+        // This happens outside of the loop to prevent needing to do a clock
+        // check and then comparison of the queue possibly multiple times a
+        // second (and thus, the clock wouldn't have changed enough to matter).
+        self.clear_expired_reset_streams();
+
+        loop {
+            // First, ensure that the `Connection` is able to receive a frame
+            //
+            // The order here matters:
+            // - poll_go_away may buffer a graceful shutdown GOAWAY frame
+            // - If it has, we've also added a PING to be sent in poll_ready
+            if let Some(reason) = ready!(self.poll_go_away(cx)?) {
+                if self.inner.go_away.should_close_now() {
+                    if self.inner.go_away.is_user_initiated() {
+                        // A user initiated abrupt shutdown shouldn't return
+                        // the same error back to the user.
+                        return Poll::Ready(Ok(()));
+                    } else {
+                        return Poll::Ready(Err(Error::library_go_away(reason)));
+                    }
+                }
+                // Only NO_ERROR should be waiting for idle
+                debug_assert_eq!(
+                    reason,
+                    Reason::NO_ERROR,
+                    "graceful GOAWAY should be NO_ERROR"
+                );
+            }
+            ready!(self.poll_ready(cx))?;
+
+            match self
+                .inner
+                .as_dyn()
+                .recv_frame(ready!(Pin::new(&mut self.codec).poll_next(cx)?))?
+            {
+                ReceivedFrame::Settings(frame) => {
+                    self.inner.settings.recv_settings(
+                        frame,
+                        &mut self.codec,
+                        &mut self.inner.streams,
+                    )?;
+                }
+                ReceivedFrame::Continue => (),
+                ReceivedFrame::Done => {
+                    return Poll::Ready(Ok(()));
+                }
+            }
+        }
+    }
+
+    fn clear_expired_reset_streams(&mut self) {
+        self.inner.streams.clear_expired_reset_streams();
+    }
+}
+
+impl<P, B> ConnectionInner<P, B>
+where
+    P: Peer,
+    B: Buf,
+{
+    fn as_dyn(&mut self) -> DynConnection<'_, B> {
+        let ConnectionInner {
+            state,
+            go_away,
+            streams,
+            error,
+            ping_pong,
+            ..
+        } = self;
+        let streams = streams.as_dyn();
+        DynConnection {
+            state,
+            go_away,
+            streams,
+            error,
+            ping_pong,
+        }
+    }
+}
+
+impl<B> DynConnection<'_, B>
+where
+    B: Buf,
+{
+    fn go_away(&mut self, id: StreamId, e: Reason) {
+        let frame = frame::GoAway::new(id, e);
+        self.streams.send_go_away(id);
+        self.go_away.go_away(frame);
+    }
+
+    fn go_away_now(&mut self, e: Reason) {
+        let last_processed_id = self.streams.last_processed_id();
+        let frame = frame::GoAway::new(last_processed_id, e);
+        self.go_away.go_away_now(frame);
+    }
+
+    fn go_away_now_data(&mut self, e: Reason, data: Bytes) {
+        let last_processed_id = self.streams.last_processed_id();
+        let frame = frame::GoAway::with_debug_data(last_processed_id, e, data);
+        self.go_away.go_away_now(frame);
+    }
+
+    fn go_away_from_user(&mut self, e: Reason) {
+        let last_processed_id = self.streams.last_processed_id();
+        let frame = frame::GoAway::new(last_processed_id, e);
+        self.go_away.go_away_from_user(frame);
+
+        // Notify all streams of reason we're abruptly closing.
+        self.streams.handle_error(Error::user_go_away(e));
+    }
+
+    fn handle_poll2_result(&mut self, result: Result<(), Error>) -> Result<(), Error> {
+        match result {
+            // The connection has shutdown normally
+            Ok(()) => {
+                *self.state = State::Closing(Reason::NO_ERROR, Initiator::Library);
+                Ok(())
+            }
+            // Attempting to read a frame resulted in a connection level
+            // error. This is handled by setting a GOAWAY frame followed by
+            // terminating the connection.
+            Err(Error::GoAway(debug_data, reason, initiator)) => {
+                self.handle_go_away(reason, debug_data, initiator);
+                Ok(())
+            }
+            // Attempting to read a frame resulted in a stream level error.
+            // This is handled by resetting the frame then trying to read
+            // another frame.
+            Err(Error::Reset(id, reason, initiator)) => {
+                debug_assert_eq!(initiator, Initiator::Library);
+                tracing::trace!(?id, ?reason, "stream error");
+                match self.streams.send_reset(id, reason) {
+                    Ok(()) => (),
+                    Err(crate::proto::error::GoAway { debug_data, reason }) => {
+                        self.handle_go_away(reason, debug_data, Initiator::Library);
+                    }
+                }
+                Ok(())
+            }
+            // Attempting to read a frame resulted in an I/O error. All
+            // active streams must be reset.
+            //
+            // TODO: Are I/O errors recoverable?
+            Err(Error::Io(kind, inner)) => {
+                tracing::debug!(error = ?kind, "Connection::poll; IO error");
+                let e = Error::Io(kind, inner);
+
+                // Reset all active streams
+                self.streams.handle_error(e.clone());
+
+                // Some client implementations drop the connections without notifying its peer
+                // Attempting to read after the client dropped the connection results in UnexpectedEof
+                // If as a server, we don't have anything more to send, just close the connection
+                // without error
+                //
+                // See https://github.com/hyperium/hyper/issues/3427
+                if self.streams.is_buffer_empty()
+                    && matches!(kind, io::ErrorKind::UnexpectedEof)
+                    && (self.streams.is_server()
+                        || self.error.as_ref().map(|f| f.reason() == Reason::NO_ERROR)
+                            == Some(true))
+                {
+                    *self.state = State::Closed(Reason::NO_ERROR, Initiator::Library);
+                    return Ok(());
+                }
+
+                // Return the error
+                Err(e)
+            }
+        }
+    }
+
+    fn handle_go_away(&mut self, reason: Reason, debug_data: Bytes, initiator: Initiator) {
+        let e = Error::GoAway(debug_data.clone(), reason, initiator);
+        tracing::debug!(error = ?e, "Connection::poll; connection error");
+
+        // We may have already sent a GOAWAY for this error,
+        // if so, don't send another, just flush and close up.
+        if self
+            .go_away
+            .going_away()
+            .map_or(false, |frame| frame.reason() == reason)
+        {
+            tracing::trace!("    -> already going away");
+            *self.state = State::Closing(reason, initiator);
+            return;
+        }
+
+        // Reset all active streams
+        self.streams.handle_error(e);
+        self.go_away_now_data(reason, debug_data);
+    }
+
+    fn recv_frame(&mut self, frame: Option<Frame>) -> Result<ReceivedFrame, Error> {
+        use crate::frame::Frame::*;
+        match frame {
+            Some(Headers(frame)) => {
+                tracing::trace!(?frame, "recv HEADERS");
+                self.streams.recv_headers(frame)?;
+            }
+            Some(Data(frame)) => {
+                tracing::trace!(?frame, "recv DATA");
+                self.streams.recv_data(frame)?;
+            }
+            Some(Reset(frame)) => {
+                tracing::trace!(?frame, "recv RST_STREAM");
+                self.streams.recv_reset(frame)?;
+            }
+            Some(PushPromise(frame)) => {
+                tracing::trace!(?frame, "recv PUSH_PROMISE");
+                self.streams.recv_push_promise(frame)?;
+            }
+            Some(Settings(frame)) => {
+                tracing::trace!(?frame, "recv SETTINGS");
+                return Ok(ReceivedFrame::Settings(frame));
+            }
+            Some(GoAway(frame)) => {
+                tracing::trace!(?frame, "recv GOAWAY");
+                // This should prevent starting new streams,
+                // but should allow continuing to process current streams
+                // until they are all EOS. Once they are, State should
+                // transition to GoAway.
+                self.streams.recv_go_away(&frame)?;
+                *self.error = Some(frame);
+            }
+            Some(Ping(frame)) => {
+                tracing::trace!(?frame, "recv PING");
+                let status = self.ping_pong.recv_ping(frame);
+                if status.is_shutdown() {
+                    assert!(
+                        self.go_away.is_going_away(),
+                        "received unexpected shutdown ping"
+                    );
+
+                    let last_processed_id = self.streams.last_processed_id();
+                    self.go_away(last_processed_id, Reason::NO_ERROR);
+                }
+            }
+            Some(WindowUpdate(frame)) => {
+                tracing::trace!(?frame, "recv WINDOW_UPDATE");
+                self.streams.recv_window_update(frame)?;
+            }
+            Some(Priority(frame)) => {
+                tracing::trace!(?frame, "recv PRIORITY");
+                // TODO: handle
+            }
+            None => {
+                tracing::trace!("codec closed");
+                self.streams.recv_eof(false).expect("mutex poisoned");
+                return Ok(ReceivedFrame::Done);
+            }
+        }
+        Ok(ReceivedFrame::Continue)
+    }
+}
+
+enum ReceivedFrame {
+    Settings(frame::Settings),
+    Continue,
+    Done,
+}
+
+impl<T, B> Connection<T, client::Peer, B>
+where
+    T: AsyncRead + AsyncWrite,
+    B: Buf,
+{
+    pub(crate) fn streams(&self) -> &Streams<B, client::Peer> {
+        &self.inner.streams
+    }
+}
+
+impl<T, B> Connection<T, server::Peer, B>
+where
+    T: AsyncRead + AsyncWrite + Unpin,
+    B: Buf,
+{
+    pub fn next_incoming(&mut self) -> Option<StreamRef<B>> {
+        self.inner.streams.next_incoming()
+    }
+
+    // Graceful shutdown only makes sense for server peers.
+    pub fn go_away_gracefully(&mut self) {
+        if self.inner.go_away.is_going_away() {
+            // No reason to start a new one.
+            return;
+        }
+
+        // According to http://httpwg.org/specs/rfc7540.html#GOAWAY:
+        //
+        // > A server that is attempting to gracefully shut down a connection
+        // > SHOULD send an initial GOAWAY frame with the last stream
+        // > identifier set to 2^31-1 and a NO_ERROR code. This signals to the
+        // > client that a shutdown is imminent and that initiating further
+        // > requests is prohibited. After allowing time for any in-flight
+        // > stream creation (at least one round-trip time), the server can
+        // > send another GOAWAY frame with an updated last stream identifier.
+        // > This ensures that a connection can be cleanly shut down without
+        // > losing requests.
+        self.inner.as_dyn().go_away(StreamId::MAX, Reason::NO_ERROR);
+
+        // We take the advice of waiting 1 RTT literally, and wait
+        // for a pong before proceeding.
+        self.inner.ping_pong.ping_shutdown();
+    }
+}
+
+impl<T, P, B> Drop for Connection<T, P, B>
+where
+    P: Peer,
+    B: Buf,
+{
+    fn drop(&mut self) {
+        // Ignore errors as this indicates that the mutex is poisoned.
+        let _ = self.inner.streams.recv_eof(true);
+    }
+}

vendor/h2/src/proto/error.rs

@@ -0,0 +1,100 @@
+use crate::codec::SendError;
+use crate::frame::{Reason, StreamId};
+
+use bytes::Bytes;
+use std::fmt;
+use std::io;
+
+/// Either an H2 reason  or an I/O error
+#[derive(Clone, Debug)]
+pub enum Error {
+    Reset(StreamId, Reason, Initiator),
+    GoAway(Bytes, Reason, Initiator),
+    Io(io::ErrorKind, Option<String>),
+}
+
+pub struct GoAway {
+    pub debug_data: Bytes,
+    pub reason: Reason,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Initiator {
+    User,
+    Library,
+    Remote,
+}
+
+impl Error {
+    pub(crate) fn is_local(&self) -> bool {
+        match *self {
+            Self::Reset(_, _, initiator) | Self::GoAway(_, _, initiator) => initiator.is_local(),
+            Self::Io(..) => true,
+        }
+    }
+
+    pub(crate) fn user_go_away(reason: Reason) -> Self {
+        Self::GoAway(Bytes::new(), reason, Initiator::User)
+    }
+
+    pub(crate) fn library_reset(stream_id: StreamId, reason: Reason) -> Self {
+        Self::Reset(stream_id, reason, Initiator::Library)
+    }
+
+    pub(crate) fn library_go_away(reason: Reason) -> Self {
+        Self::GoAway(Bytes::new(), reason, Initiator::Library)
+    }
+
+    pub(crate) fn library_go_away_data(reason: Reason, debug_data: impl Into<Bytes>) -> Self {
+        Self::GoAway(debug_data.into(), reason, Initiator::Library)
+    }
+
+    pub(crate) fn remote_reset(stream_id: StreamId, reason: Reason) -> Self {
+        Self::Reset(stream_id, reason, Initiator::Remote)
+    }
+
+    pub(crate) fn remote_go_away(debug_data: Bytes, reason: Reason) -> Self {
+        Self::GoAway(debug_data, reason, Initiator::Remote)
+    }
+}
+
+impl Initiator {
+    fn is_local(&self) -> bool {
+        match *self {
+            Self::User | Self::Library => true,
+            Self::Remote => false,
+        }
+    }
+
+    pub(crate) fn is_library(&self) -> bool {
+        matches!(self, Self::Library)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Self::Reset(_, reason, _) | Self::GoAway(_, reason, _) => reason.fmt(fmt),
+            Self::Io(_, Some(ref inner)) => inner.fmt(fmt),
+            Self::Io(kind, None) => io::Error::from(kind).fmt(fmt),
+        }
+    }
+}
+
+impl From<io::ErrorKind> for Error {
+    fn from(src: io::ErrorKind) -> Self {
+        Error::Io(src, None)
+    }
+}
+
+impl From<io::Error> for Error {
+    fn from(src: io::Error) -> Self {
+        Error::Io(src.kind(), src.get_ref().map(|inner| inner.to_string()))
+    }
+}
+
+impl From<Error> for SendError {
+    fn from(src: Error) -> Self {
+        Self::Connection(src)
+    }
+}

vendor/h2/src/proto/go_away.rs

@@ -0,0 +1,154 @@
+use crate::codec::Codec;
+use crate::frame::{self, Reason, StreamId};
+
+use bytes::Buf;
+use std::io;
+use std::task::{Context, Poll};
+use tokio::io::AsyncWrite;
+
+/// Manages our sending of GOAWAY frames.
+#[derive(Debug)]
+pub(super) struct GoAway {
+    /// Whether the connection should close now, or wait until idle.
+    close_now: bool,
+    /// Records if we've sent any GOAWAY before.
+    going_away: Option<GoingAway>,
+    /// Whether the user started the GOAWAY by calling `abrupt_shutdown`.
+    is_user_initiated: bool,
+    /// A GOAWAY frame that must be buffered in the Codec immediately.
+    pending: Option<frame::GoAway>,
+}
+
+/// Keeps a memory of any GOAWAY frames we've sent before.
+///
+/// This looks very similar to a `frame::GoAway`, but is a separate type. Why?
+/// Mostly for documentation purposes. This type is to record status. If it
+/// were a `frame::GoAway`, it might appear like we eventually wanted to
+/// serialize it. We **only** want to be able to look up these fields at a
+/// later time.
+#[derive(Debug)]
+pub(crate) struct GoingAway {
+    /// Stores the highest stream ID of a GOAWAY that has been sent.
+    ///
+    /// It's illegal to send a subsequent GOAWAY with a higher ID.
+    last_processed_id: StreamId,
+
+    /// Records the error code of any GOAWAY frame sent.
+    reason: Reason,
+}
+
+impl GoAway {
+    pub fn new() -> Self {
+        GoAway {
+            close_now: false,
+            going_away: None,
+            is_user_initiated: false,
+            pending: None,
+        }
+    }
+
+    /// Enqueue a GOAWAY frame to be written.
+    ///
+    /// The connection is expected to continue to run until idle.
+    pub fn go_away(&mut self, f: frame::GoAway) {
+        if let Some(ref going_away) = self.going_away {
+            assert!(
+                f.last_stream_id() <= going_away.last_processed_id,
+                "GOAWAY stream IDs shouldn't be higher; \
+                 last_processed_id = {:?}, f.last_stream_id() = {:?}",
+                going_away.last_processed_id,
+                f.last_stream_id(),
+            );
+        }
+
+        self.going_away = Some(GoingAway {
+            last_processed_id: f.last_stream_id(),
+            reason: f.reason(),
+        });
+        self.pending = Some(f);
+    }
+
+    pub fn go_away_now(&mut self, f: frame::GoAway) {
+        self.close_now = true;
+        if let Some(ref going_away) = self.going_away {
+            // Prevent sending the same GOAWAY twice.
+            if going_away.last_processed_id == f.last_stream_id() && going_away.reason == f.reason()
+            {
+                return;
+            }
+        }
+        self.go_away(f);
+    }
+
+    pub fn go_away_from_user(&mut self, f: frame::GoAway) {
+        self.is_user_initiated = true;
+        self.go_away_now(f);
+    }
+
+    /// Return if a GOAWAY has ever been scheduled.
+    pub fn is_going_away(&self) -> bool {
+        self.going_away.is_some()
+    }
+
+    pub fn is_user_initiated(&self) -> bool {
+        self.is_user_initiated
+    }
+
+    /// Returns the going away info, if any.
+    pub fn going_away(&self) -> Option<&GoingAway> {
+        self.going_away.as_ref()
+    }
+
+    /// Returns if the connection should close now, or wait until idle.
+    pub fn should_close_now(&self) -> bool {
+        self.pending.is_none() && self.close_now
+    }
+
+    /// Returns if the connection should be closed when idle.
+    pub fn should_close_on_idle(&self) -> bool {
+        !self.close_now
+            && self
+                .going_away
+                .as_ref()
+                .map(|g| g.last_processed_id != StreamId::MAX)
+                .unwrap_or(false)
+    }
+
+    /// Try to write a pending GOAWAY frame to the buffer.
+    ///
+    /// If a frame is written, the `Reason` of the GOAWAY is returned.
+    pub fn send_pending_go_away<T, B>(
+        &mut self,
+        cx: &mut Context,
+        dst: &mut Codec<T, B>,
+    ) -> Poll<Option<io::Result<Reason>>>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+    {
+        if let Some(frame) = self.pending.take() {
+            if !dst.poll_ready(cx)?.is_ready() {
+                self.pending = Some(frame);
+                return Poll::Pending;
+            }
+
+            let reason = frame.reason();
+            dst.buffer(frame.into()).expect("invalid GOAWAY frame");
+
+            return Poll::Ready(Some(Ok(reason)));
+        } else if self.should_close_now() {
+            return match self.going_away().map(|going_away| going_away.reason) {
+                Some(reason) => Poll::Ready(Some(Ok(reason))),
+                None => Poll::Ready(None),
+            };
+        }
+
+        Poll::Ready(None)
+    }
+}
+
+impl GoingAway {
+    pub(crate) fn reason(&self) -> Reason {
+        self.reason
+    }
+}

vendor/h2/src/proto/mod.rs

@@ -0,0 +1,42 @@
+mod connection;
+mod error;
+mod go_away;
+mod peer;
+mod ping_pong;
+mod settings;
+mod streams;
+
+pub(crate) use self::connection::{Config, Connection};
+pub use self::error::{Error, Initiator};
+pub(crate) use self::peer::{Dyn as DynPeer, Peer};
+pub(crate) use self::ping_pong::UserPings;
+pub(crate) use self::streams::{DynStreams, OpaqueStreamRef, StreamRef, Streams};
+pub(crate) use self::streams::{Open, PollReset, Prioritized};
+
+use crate::codec::Codec;
+
+use self::go_away::GoAway;
+use self::ping_pong::PingPong;
+use self::settings::Settings;
+
+use crate::frame::{self, Frame};
+
+use bytes::Buf;
+
+use tokio::io::AsyncWrite;
+
+pub type PingPayload = [u8; 8];
+
+pub type WindowSize = u32;
+
+// Constants
+pub const MAX_WINDOW_SIZE: WindowSize = (1 << 31) - 1; // i32::MAX as u32
+pub const DEFAULT_REMOTE_RESET_STREAM_MAX: usize = 20;
+pub const DEFAULT_LOCAL_RESET_COUNT_MAX: usize = 1024;
+// RFC 9113 suggests allowing at minimum 100 streams, it seems reasonable to
+// by default allow a portion of that to be remembered as reset for some time.
+pub const DEFAULT_RESET_STREAM_MAX: usize = 50;
+// RFC 9113#5.4.2 suggests ~1 RTT. We don't track that closely, but use a
+// reasonable guess of the average here.
+pub const DEFAULT_RESET_STREAM_SECS: u64 = 1;
+pub const DEFAULT_MAX_SEND_BUFFER_SIZE: usize = 1024 * 400;

vendor/h2/src/proto/peer.rs

@@ -0,0 +1,95 @@
+use crate::error::Reason;
+use crate::frame::{Pseudo, StreamId};
+use crate::proto::{Error, Open};
+
+use http::{HeaderMap, Request, Response};
+
+use std::fmt;
+
+/// Either a Client or a Server
+pub(crate) trait Peer {
+    /// Message type polled from the transport
+    type Poll: fmt::Debug;
+    const NAME: &'static str;
+
+    fn r#dyn() -> Dyn;
+
+    //fn is_server() -> bool;
+
+    fn convert_poll_message(
+        pseudo: Pseudo,
+        fields: HeaderMap,
+        stream_id: StreamId,
+    ) -> Result<Self::Poll, Error>;
+
+    /*
+    fn is_local_init(id: StreamId) -> bool {
+        assert!(!id.is_zero());
+        Self::is_server() == id.is_server_initiated()
+    }
+    */
+}
+
+/// A dynamic representation of `Peer`.
+///
+/// This is used internally to avoid incurring a generic on all internal types.
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(crate) enum Dyn {
+    Client,
+    Server,
+}
+
+#[derive(Debug)]
+pub enum PollMessage {
+    Client(Response<()>),
+    Server(Request<()>),
+}
+
+// ===== impl Dyn =====
+
+impl Dyn {
+    pub fn is_server(&self) -> bool {
+        *self == Dyn::Server
+    }
+
+    pub fn is_local_init(&self, id: StreamId) -> bool {
+        assert!(!id.is_zero());
+        self.is_server() == id.is_server_initiated()
+    }
+
+    pub fn convert_poll_message(
+        &self,
+        pseudo: Pseudo,
+        fields: HeaderMap,
+        stream_id: StreamId,
+    ) -> Result<PollMessage, Error> {
+        if self.is_server() {
+            crate::server::Peer::convert_poll_message(pseudo, fields, stream_id)
+                .map(PollMessage::Server)
+        } else {
+            crate::client::Peer::convert_poll_message(pseudo, fields, stream_id)
+                .map(PollMessage::Client)
+        }
+    }
+
+    /// Returns true if the remote peer can initiate a stream with the given ID.
+    pub fn ensure_can_open(&self, id: StreamId, mode: Open) -> Result<(), Error> {
+        if self.is_server() {
+            // Ensure that the ID is a valid client initiated ID
+            if mode.is_push_promise() || !id.is_client_initiated() {
+                proto_err!(conn: "cannot open stream {:?} - not client initiated", id);
+                return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+            }
+
+            Ok(())
+        } else {
+            // Ensure that the ID is a valid server initiated ID
+            if !mode.is_push_promise() || !id.is_server_initiated() {
+                proto_err!(conn: "cannot open stream {:?} - not server initiated", id);
+                return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+            }
+
+            Ok(())
+        }
+    }
+}

vendor/h2/src/proto/ping_pong.rs

@@ -0,0 +1,291 @@
+use crate::codec::Codec;
+use crate::frame::Ping;
+use crate::proto::{self, PingPayload};
+
+use atomic_waker::AtomicWaker;
+use bytes::Buf;
+use std::io;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::task::{Context, Poll};
+use tokio::io::AsyncWrite;
+
+/// Acknowledges ping requests from the remote.
+#[derive(Debug)]
+pub(crate) struct PingPong {
+    pending_ping: Option<PendingPing>,
+    pending_pong: Option<PingPayload>,
+    user_pings: Option<UserPingsRx>,
+}
+
+#[derive(Debug)]
+pub(crate) struct UserPings(Arc<UserPingsInner>);
+
+#[derive(Debug)]
+struct UserPingsRx(Arc<UserPingsInner>);
+
+#[derive(Debug)]
+struct UserPingsInner {
+    state: AtomicUsize,
+    /// Task to wake up the main `Connection`.
+    ping_task: AtomicWaker,
+    /// Task to wake up `share::PingPong::poll_pong`.
+    pong_task: AtomicWaker,
+}
+
+#[derive(Debug)]
+struct PendingPing {
+    payload: PingPayload,
+    sent: bool,
+}
+
+/// Status returned from `PingPong::recv_ping`.
+#[derive(Debug)]
+pub(crate) enum ReceivedPing {
+    MustAck,
+    Unknown,
+    Shutdown,
+}
+
+/// No user ping pending.
+const USER_STATE_EMPTY: usize = 0;
+/// User has called `send_ping`, but PING hasn't been written yet.
+const USER_STATE_PENDING_PING: usize = 1;
+/// User PING has been written, waiting for PONG.
+const USER_STATE_PENDING_PONG: usize = 2;
+/// We've received user PONG, waiting for user to `poll_pong`.
+const USER_STATE_RECEIVED_PONG: usize = 3;
+/// The connection is closed.
+const USER_STATE_CLOSED: usize = 4;
+
+// ===== impl PingPong =====
+
+impl PingPong {
+    pub(crate) fn new() -> Self {
+        PingPong {
+            pending_ping: None,
+            pending_pong: None,
+            user_pings: None,
+        }
+    }
+
+    /// Can only be called once. If called a second time, returns `None`.
+    pub(crate) fn take_user_pings(&mut self) -> Option<UserPings> {
+        if self.user_pings.is_some() {
+            return None;
+        }
+
+        let user_pings = Arc::new(UserPingsInner {
+            state: AtomicUsize::new(USER_STATE_EMPTY),
+            ping_task: AtomicWaker::new(),
+            pong_task: AtomicWaker::new(),
+        });
+        self.user_pings = Some(UserPingsRx(user_pings.clone()));
+        Some(UserPings(user_pings))
+    }
+
+    pub(crate) fn ping_shutdown(&mut self) {
+        assert!(self.pending_ping.is_none());
+
+        self.pending_ping = Some(PendingPing {
+            payload: Ping::SHUTDOWN,
+            sent: false,
+        });
+    }
+
+    /// Process a ping
+    pub(crate) fn recv_ping(&mut self, ping: Ping) -> ReceivedPing {
+        // The caller should always check that `send_pongs` returns ready before
+        // calling `recv_ping`.
+        assert!(self.pending_pong.is_none());
+
+        if ping.is_ack() {
+            if let Some(pending) = self.pending_ping.take() {
+                if &pending.payload == ping.payload() {
+                    assert_eq!(
+                        &pending.payload,
+                        &Ping::SHUTDOWN,
+                        "pending_ping should be for shutdown",
+                    );
+                    tracing::trace!("recv PING SHUTDOWN ack");
+                    return ReceivedPing::Shutdown;
+                }
+
+                // if not the payload we expected, put it back.
+                self.pending_ping = Some(pending);
+            }
+
+            if let Some(ref users) = self.user_pings {
+                if ping.payload() == &Ping::USER && users.receive_pong() {
+                    tracing::trace!("recv PING USER ack");
+                    return ReceivedPing::Unknown;
+                }
+            }
+
+            // else we were acked a ping we didn't send?
+            // The spec doesn't require us to do anything about this,
+            // so for resiliency, just ignore it for now.
+            tracing::warn!("recv PING ack that we never sent: {:?}", ping);
+            ReceivedPing::Unknown
+        } else {
+            // Save the ping's payload to be sent as an acknowledgement.
+            self.pending_pong = Some(ping.into_payload());
+            ReceivedPing::MustAck
+        }
+    }
+
+    /// Send any pending pongs.
+    pub(crate) fn send_pending_pong<T, B>(
+        &mut self,
+        cx: &mut Context,
+        dst: &mut Codec<T, B>,
+    ) -> Poll<io::Result<()>>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+    {
+        if let Some(pong) = self.pending_pong.take() {
+            if !dst.poll_ready(cx)?.is_ready() {
+                self.pending_pong = Some(pong);
+                return Poll::Pending;
+            }
+
+            dst.buffer(Ping::pong(pong).into())
+                .expect("invalid pong frame");
+        }
+
+        Poll::Ready(Ok(()))
+    }
+
+    /// Send any pending pings.
+    pub(crate) fn send_pending_ping<T, B>(
+        &mut self,
+        cx: &mut Context,
+        dst: &mut Codec<T, B>,
+    ) -> Poll<io::Result<()>>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+    {
+        if let Some(ref mut ping) = self.pending_ping {
+            if !ping.sent {
+                if !dst.poll_ready(cx)?.is_ready() {
+                    return Poll::Pending;
+                }
+
+                dst.buffer(Ping::new(ping.payload).into())
+                    .expect("invalid ping frame");
+                ping.sent = true;
+            }
+        } else if let Some(ref users) = self.user_pings {
+            if users.0.state.load(Ordering::Acquire) == USER_STATE_PENDING_PING {
+                if !dst.poll_ready(cx)?.is_ready() {
+                    return Poll::Pending;
+                }
+
+                dst.buffer(Ping::new(Ping::USER).into())
+                    .expect("invalid ping frame");
+                users
+                    .0
+                    .state
+                    .store(USER_STATE_PENDING_PONG, Ordering::Release);
+            } else {
+                users.0.ping_task.register(cx.waker());
+            }
+        }
+
+        Poll::Ready(Ok(()))
+    }
+}
+
+impl ReceivedPing {
+    pub(crate) fn is_shutdown(&self) -> bool {
+        matches!(*self, Self::Shutdown)
+    }
+}
+
+// ===== impl UserPings =====
+
+impl UserPings {
+    pub(crate) fn send_ping(&self) -> Result<(), Option<proto::Error>> {
+        let prev = self
+            .0
+            .state
+            .compare_exchange(
+                USER_STATE_EMPTY,        // current
+                USER_STATE_PENDING_PING, // new
+                Ordering::AcqRel,
+                Ordering::Acquire,
+            )
+            .unwrap_or_else(|v| v);
+
+        match prev {
+            USER_STATE_EMPTY => {
+                self.0.ping_task.wake();
+                Ok(())
+            }
+            USER_STATE_CLOSED => Err(Some(broken_pipe().into())),
+            _ => {
+                // Was already pending, user error!
+                Err(None)
+            }
+        }
+    }
+
+    pub(crate) fn poll_pong(&self, cx: &mut Context) -> Poll<Result<(), proto::Error>> {
+        // Must register before checking state, in case state were to change
+        // before we could register, and then the ping would just be lost.
+        self.0.pong_task.register(cx.waker());
+        let prev = self
+            .0
+            .state
+            .compare_exchange(
+                USER_STATE_RECEIVED_PONG, // current
+                USER_STATE_EMPTY,         // new
+                Ordering::AcqRel,
+                Ordering::Acquire,
+            )
+            .unwrap_or_else(|v| v);
+
+        match prev {
+            USER_STATE_RECEIVED_PONG => Poll::Ready(Ok(())),
+            USER_STATE_CLOSED => Poll::Ready(Err(broken_pipe().into())),
+            _ => Poll::Pending,
+        }
+    }
+}
+
+// ===== impl UserPingsRx =====
+
+impl UserPingsRx {
+    fn receive_pong(&self) -> bool {
+        let prev = self
+            .0
+            .state
+            .compare_exchange(
+                USER_STATE_PENDING_PONG,  // current
+                USER_STATE_RECEIVED_PONG, // new
+                Ordering::AcqRel,
+                Ordering::Acquire,
+            )
+            .unwrap_or_else(|v| v);
+
+        if prev == USER_STATE_PENDING_PONG {
+            self.0.pong_task.wake();
+            true
+        } else {
+            false
+        }
+    }
+}
+
+impl Drop for UserPingsRx {
+    fn drop(&mut self) {
+        self.0.state.store(USER_STATE_CLOSED, Ordering::Release);
+        self.0.pong_task.wake();
+    }
+}
+
+fn broken_pipe() -> io::Error {
+    io::ErrorKind::BrokenPipe.into()
+}

vendor/h2/src/proto/settings.rs

@@ -0,0 +1,168 @@
+use crate::codec::UserError;
+use crate::error::Reason;
+use crate::proto::*;
+use std::task::{Context, Poll};
+
+#[derive(Debug)]
+pub(crate) struct Settings {
+    /// Our local SETTINGS sync state with the remote.
+    local: Local,
+    /// Received SETTINGS frame pending processing. The ACK must be written to
+    /// the socket first then the settings applied **before** receiving any
+    /// further frames.
+    remote: Option<frame::Settings>,
+    /// Whether the connection has received the initial SETTINGS frame from the
+    /// remote peer.
+    has_received_remote_initial_settings: bool,
+}
+
+#[derive(Debug)]
+enum Local {
+    /// We want to send these SETTINGS to the remote when the socket is ready.
+    ToSend(frame::Settings),
+    /// We have sent these SETTINGS and are waiting for the remote to ACK
+    /// before we apply them.
+    WaitingAck(frame::Settings),
+    /// Our local settings are in sync with the remote.
+    Synced,
+}
+
+impl Settings {
+    pub(crate) fn new(local: frame::Settings) -> Self {
+        Settings {
+            // We assume the initial local SETTINGS were flushed during
+            // the handshake process.
+            local: Local::WaitingAck(local),
+            remote: None,
+            has_received_remote_initial_settings: false,
+        }
+    }
+
+    pub(crate) fn recv_settings<T, B, C, P>(
+        &mut self,
+        frame: frame::Settings,
+        codec: &mut Codec<T, B>,
+        streams: &mut Streams<C, P>,
+    ) -> Result<(), Error>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+        C: Buf,
+        P: Peer,
+    {
+        if frame.is_ack() {
+            match &self.local {
+                Local::WaitingAck(local) => {
+                    tracing::debug!("received settings ACK; applying {:?}", local);
+
+                    if let Some(max) = local.max_frame_size() {
+                        codec.set_max_recv_frame_size(max as usize);
+                    }
+
+                    if let Some(max) = local.max_header_list_size() {
+                        codec.set_max_recv_header_list_size(max as usize);
+                    }
+
+                    if let Some(val) = local.header_table_size() {
+                        codec.set_recv_header_table_size(val as usize);
+                    }
+
+                    streams.apply_local_settings(local)?;
+                    self.local = Local::Synced;
+                    Ok(())
+                }
+                Local::ToSend(..) | Local::Synced => {
+                    // We haven't sent any SETTINGS frames to be ACKed, so
+                    // this is very bizarre! Remote is either buggy or malicious.
+                    proto_err!(conn: "received unexpected settings ack");
+                    Err(Error::library_go_away(Reason::PROTOCOL_ERROR))
+                }
+            }
+        } else {
+            // We always ACK before reading more frames, so `remote` should
+            // always be none!
+            assert!(self.remote.is_none());
+            self.remote = Some(frame);
+            Ok(())
+        }
+    }
+
+    pub(crate) fn send_settings(&mut self, frame: frame::Settings) -> Result<(), UserError> {
+        assert!(!frame.is_ack());
+        match &self.local {
+            Local::ToSend(..) | Local::WaitingAck(..) => Err(UserError::SendSettingsWhilePending),
+            Local::Synced => {
+                tracing::trace!("queue to send local settings: {:?}", frame);
+                self.local = Local::ToSend(frame);
+                Ok(())
+            }
+        }
+    }
+
+    /// Sets `true` to `self.has_received_remote_initial_settings`.
+    /// Returns `true` if this method is called for the first time.
+    /// (i.e. it is the initial SETTINGS frame from the remote peer)
+    fn mark_remote_initial_settings_as_received(&mut self) -> bool {
+        let has_received = self.has_received_remote_initial_settings;
+        self.has_received_remote_initial_settings = true;
+        !has_received
+    }
+
+    pub(crate) fn poll_send<T, B, C, P>(
+        &mut self,
+        cx: &mut Context,
+        dst: &mut Codec<T, B>,
+        streams: &mut Streams<C, P>,
+    ) -> Poll<Result<(), Error>>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+        C: Buf,
+        P: Peer,
+    {
+        if let Some(settings) = self.remote.clone() {
+            if !dst.poll_ready(cx)?.is_ready() {
+                return Poll::Pending;
+            }
+
+            // Create an ACK settings frame
+            let frame = frame::Settings::ack();
+
+            // Buffer the settings frame
+            dst.buffer(frame.into()).expect("invalid settings frame");
+
+            tracing::trace!("ACK sent; applying settings");
+
+            let is_initial = self.mark_remote_initial_settings_as_received();
+            streams.apply_remote_settings(&settings, is_initial)?;
+
+            if let Some(val) = settings.header_table_size() {
+                dst.set_send_header_table_size(val as usize);
+            }
+
+            if let Some(val) = settings.max_frame_size() {
+                dst.set_max_send_frame_size(val as usize);
+            }
+        }
+
+        self.remote = None;
+
+        match &self.local {
+            Local::ToSend(settings) => {
+                if !dst.poll_ready(cx)?.is_ready() {
+                    return Poll::Pending;
+                }
+
+                // Buffer the settings frame
+                dst.buffer(settings.clone().into())
+                    .expect("invalid settings frame");
+                tracing::trace!("local settings sent; waiting for ack: {:?}", settings);
+
+                self.local = Local::WaitingAck(settings.clone());
+            }
+            Local::WaitingAck(..) | Local::Synced => {}
+        }
+
+        Poll::Ready(Ok(()))
+    }
+}

vendor/h2/src/proto/streams/buffer.rs

@@ -0,0 +1,99 @@
+use slab::Slab;
+
+/// Buffers frames for multiple streams.
+#[derive(Debug)]
+pub struct Buffer<T> {
+    slab: Slab<Slot<T>>,
+}
+
+/// A sequence of frames in a `Buffer`
+#[derive(Debug)]
+pub struct Deque {
+    indices: Option<Indices>,
+}
+
+/// Tracks the head & tail for a sequence of frames in a `Buffer`.
+#[derive(Debug, Default, Copy, Clone)]
+struct Indices {
+    head: usize,
+    tail: usize,
+}
+
+#[derive(Debug)]
+struct Slot<T> {
+    value: T,
+    next: Option<usize>,
+}
+
+impl<T> Buffer<T> {
+    pub fn new() -> Self {
+        Buffer { slab: Slab::new() }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.slab.is_empty()
+    }
+}
+
+impl Deque {
+    pub fn new() -> Self {
+        Deque { indices: None }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.indices.is_none()
+    }
+
+    pub fn push_back<T>(&mut self, buf: &mut Buffer<T>, value: T) {
+        let key = buf.slab.insert(Slot { value, next: None });
+
+        match self.indices {
+            Some(ref mut idxs) => {
+                buf.slab[idxs.tail].next = Some(key);
+                idxs.tail = key;
+            }
+            None => {
+                self.indices = Some(Indices {
+                    head: key,
+                    tail: key,
+                });
+            }
+        }
+    }
+
+    pub fn push_front<T>(&mut self, buf: &mut Buffer<T>, value: T) {
+        let key = buf.slab.insert(Slot { value, next: None });
+
+        match self.indices {
+            Some(ref mut idxs) => {
+                buf.slab[key].next = Some(idxs.head);
+                idxs.head = key;
+            }
+            None => {
+                self.indices = Some(Indices {
+                    head: key,
+                    tail: key,
+                });
+            }
+        }
+    }
+
+    pub fn pop_front<T>(&mut self, buf: &mut Buffer<T>) -> Option<T> {
+        match self.indices {
+            Some(mut idxs) => {
+                let mut slot = buf.slab.remove(idxs.head);
+
+                if idxs.head == idxs.tail {
+                    assert!(slot.next.is_none());
+                    self.indices = None;
+                } else {
+                    idxs.head = slot.next.take().unwrap();
+                    self.indices = Some(idxs);
+                }
+
+                Some(slot.value)
+            }
+            None => None,
+        }
+    }
+}

vendor/h2/src/proto/streams/counts.rs

@@ -0,0 +1,285 @@
+use super::*;
+
+#[derive(Debug)]
+pub(super) struct Counts {
+    /// Acting as a client or server. This allows us to track which values to
+    /// inc / dec.
+    peer: peer::Dyn,
+
+    /// Maximum number of locally initiated streams
+    max_send_streams: usize,
+
+    /// Current number of remote initiated streams
+    num_send_streams: usize,
+
+    /// Maximum number of remote initiated streams
+    max_recv_streams: usize,
+
+    /// Current number of locally initiated streams
+    num_recv_streams: usize,
+
+    /// Maximum number of pending locally reset streams
+    max_local_reset_streams: usize,
+
+    /// Current number of pending locally reset streams
+    num_local_reset_streams: usize,
+
+    /// Max number of "pending accept" streams that were remotely reset
+    max_remote_reset_streams: usize,
+
+    /// Current number of "pending accept" streams that were remotely reset
+    num_remote_reset_streams: usize,
+
+    /// Maximum number of locally reset streams due to protocol error across
+    /// the lifetime of the connection.
+    ///
+    /// When this gets exceeded, we issue GOAWAYs.
+    max_local_error_reset_streams: Option<usize>,
+
+    /// Total number of locally reset streams due to protocol error across the
+    /// lifetime of the connection.
+    num_local_error_reset_streams: usize,
+}
+
+impl Counts {
+    /// Create a new `Counts` using the provided configuration values.
+    pub fn new(peer: peer::Dyn, config: &Config) -> Self {
+        Counts {
+            peer,
+            max_send_streams: config.initial_max_send_streams,
+            num_send_streams: 0,
+            max_recv_streams: config.remote_max_initiated.unwrap_or(usize::MAX),
+            num_recv_streams: 0,
+            max_local_reset_streams: config.local_reset_max,
+            num_local_reset_streams: 0,
+            max_remote_reset_streams: config.remote_reset_max,
+            num_remote_reset_streams: 0,
+            max_local_error_reset_streams: config.local_max_error_reset_streams,
+            num_local_error_reset_streams: 0,
+        }
+    }
+
+    /// Returns true when the next opened stream will reach capacity of outbound streams
+    ///
+    /// The number of client send streams is incremented in prioritize; send_request has to guess if
+    /// it should wait before allowing another request to be sent.
+    pub fn next_send_stream_will_reach_capacity(&self) -> bool {
+        self.max_send_streams <= (self.num_send_streams + 1)
+    }
+
+    /// Returns the current peer
+    pub fn peer(&self) -> peer::Dyn {
+        self.peer
+    }
+
+    pub fn has_streams(&self) -> bool {
+        self.num_send_streams != 0 || self.num_recv_streams != 0
+    }
+
+    /// Returns true if we can issue another local reset due to protocol error.
+    pub fn can_inc_num_local_error_resets(&self) -> bool {
+        if let Some(max) = self.max_local_error_reset_streams {
+            max > self.num_local_error_reset_streams
+        } else {
+            true
+        }
+    }
+
+    pub fn inc_num_local_error_resets(&mut self) {
+        assert!(self.can_inc_num_local_error_resets());
+
+        // Increment the number of remote initiated streams
+        self.num_local_error_reset_streams += 1;
+    }
+
+    pub(crate) fn max_local_error_resets(&self) -> Option<usize> {
+        self.max_local_error_reset_streams
+    }
+
+    /// Returns true if the receive stream concurrency can be incremented
+    pub fn can_inc_num_recv_streams(&self) -> bool {
+        self.max_recv_streams > self.num_recv_streams
+    }
+
+    /// Increments the number of concurrent receive streams.
+    ///
+    /// # Panics
+    ///
+    /// Panics on failure as this should have been validated before hand.
+    pub fn inc_num_recv_streams(&mut self, stream: &mut store::Ptr) {
+        assert!(self.can_inc_num_recv_streams());
+        assert!(!stream.is_counted);
+
+        // Increment the number of remote initiated streams
+        self.num_recv_streams += 1;
+        stream.is_counted = true;
+    }
+
+    /// Returns true if the send stream concurrency can be incremented
+    pub fn can_inc_num_send_streams(&self) -> bool {
+        self.max_send_streams > self.num_send_streams
+    }
+
+    /// Increments the number of concurrent send streams.
+    ///
+    /// # Panics
+    ///
+    /// Panics on failure as this should have been validated before hand.
+    pub fn inc_num_send_streams(&mut self, stream: &mut store::Ptr) {
+        assert!(self.can_inc_num_send_streams());
+        assert!(!stream.is_counted);
+
+        // Increment the number of remote initiated streams
+        self.num_send_streams += 1;
+        stream.is_counted = true;
+    }
+
+    /// Returns true if the number of pending reset streams can be incremented.
+    pub fn can_inc_num_reset_streams(&self) -> bool {
+        self.max_local_reset_streams > self.num_local_reset_streams
+    }
+
+    /// Increments the number of pending reset streams.
+    ///
+    /// # Panics
+    ///
+    /// Panics on failure as this should have been validated before hand.
+    pub fn inc_num_reset_streams(&mut self) {
+        assert!(self.can_inc_num_reset_streams());
+
+        self.num_local_reset_streams += 1;
+    }
+
+    pub(crate) fn max_remote_reset_streams(&self) -> usize {
+        self.max_remote_reset_streams
+    }
+
+    /// Returns true if the number of pending REMOTE reset streams can be
+    /// incremented.
+    pub(crate) fn can_inc_num_remote_reset_streams(&self) -> bool {
+        self.max_remote_reset_streams > self.num_remote_reset_streams
+    }
+
+    /// Increments the number of pending REMOTE reset streams.
+    ///
+    /// # Panics
+    ///
+    /// Panics on failure as this should have been validated before hand.
+    pub(crate) fn inc_num_remote_reset_streams(&mut self) {
+        assert!(self.can_inc_num_remote_reset_streams());
+
+        self.num_remote_reset_streams += 1;
+    }
+
+    pub(crate) fn dec_num_remote_reset_streams(&mut self) {
+        assert!(self.num_remote_reset_streams > 0);
+
+        self.num_remote_reset_streams -= 1;
+    }
+
+    pub fn apply_remote_settings(&mut self, settings: &frame::Settings, is_initial: bool) {
+        match settings.max_concurrent_streams() {
+            Some(val) => self.max_send_streams = val as usize,
+            None if is_initial => self.max_send_streams = usize::MAX,
+            None => {}
+        }
+    }
+
+    /// Run a block of code that could potentially transition a stream's state.
+    ///
+    /// If the stream state transitions to closed, this function will perform
+    /// all necessary cleanup.
+    ///
+    /// TODO: Is this function still needed?
+    pub fn transition<F, U>(&mut self, mut stream: store::Ptr, f: F) -> U
+    where
+        F: FnOnce(&mut Self, &mut store::Ptr) -> U,
+    {
+        // TODO: Does this need to be computed before performing the action?
+        let is_pending_reset = stream.is_pending_reset_expiration();
+
+        // Run the action
+        let ret = f(self, &mut stream);
+
+        self.transition_after(stream, is_pending_reset);
+
+        ret
+    }
+
+    // TODO: move this to macro?
+    pub fn transition_after(&mut self, mut stream: store::Ptr, is_reset_counted: bool) {
+        tracing::trace!(
+            "transition_after; stream={:?}; state={:?}; is_closed={:?}; \
+             pending_send_empty={:?}; buffered_send_data={}; \
+             num_recv={}; num_send={}",
+            stream.id,
+            stream.state,
+            stream.is_closed(),
+            stream.pending_send.is_empty(),
+            stream.buffered_send_data,
+            self.num_recv_streams,
+            self.num_send_streams
+        );
+
+        if stream.is_closed() {
+            if !stream.is_pending_reset_expiration() {
+                stream.unlink();
+                if is_reset_counted {
+                    self.dec_num_reset_streams();
+                }
+            }
+
+            if !stream.state.is_scheduled_reset() && stream.is_counted {
+                tracing::trace!("dec_num_streams; stream={:?}", stream.id);
+                // Decrement the number of active streams.
+                self.dec_num_streams(&mut stream);
+            }
+        }
+
+        // Release the stream if it requires releasing
+        if stream.is_released() {
+            stream.remove();
+        }
+    }
+
+    /// Returns the maximum number of streams that can be initiated by this
+    /// peer.
+    pub(crate) fn max_send_streams(&self) -> usize {
+        self.max_send_streams
+    }
+
+    /// Returns the maximum number of streams that can be initiated by the
+    /// remote peer.
+    pub(crate) fn max_recv_streams(&self) -> usize {
+        self.max_recv_streams
+    }
+
+    fn dec_num_streams(&mut self, stream: &mut store::Ptr) {
+        assert!(stream.is_counted);
+
+        if self.peer.is_local_init(stream.id) {
+            assert!(self.num_send_streams > 0);
+            self.num_send_streams -= 1;
+            stream.is_counted = false;
+        } else {
+            assert!(self.num_recv_streams > 0);
+            self.num_recv_streams -= 1;
+            stream.is_counted = false;
+        }
+    }
+
+    fn dec_num_reset_streams(&mut self) {
+        assert!(self.num_local_reset_streams > 0);
+        self.num_local_reset_streams -= 1;
+    }
+}
+
+impl Drop for Counts {
+    fn drop(&mut self) {
+        use std::thread;
+
+        if !thread::panicking() {
+            debug_assert!(!self.has_streams());
+        }
+    }
+}

vendor/h2/src/proto/streams/flow_control.rs

@@ -0,0 +1,269 @@
+use crate::frame::Reason;
+use crate::proto::{WindowSize, MAX_WINDOW_SIZE};
+
+use std::fmt;
+
+// We don't want to send WINDOW_UPDATE frames for tiny changes, but instead
+// aggregate them when the changes are significant. Many implementations do
+// this by keeping a "ratio" of the update version the allowed window size.
+//
+// While some may wish to represent this ratio as percentage, using a f32,
+// we skip having to deal with float math and stick to integers. To do so,
+// the "ratio" is represented by 2 i32s, split into the numerator and
+// denominator. For example, a 50% ratio is simply represented as 1/2.
+//
+// An example applying this ratio: If a stream has an allowed window size of
+// 100 bytes, WINDOW_UPDATE frames are scheduled when the unclaimed change
+// becomes greater than 1/2, or 50 bytes.
+const UNCLAIMED_NUMERATOR: i32 = 1;
+const UNCLAIMED_DENOMINATOR: i32 = 2;
+
+#[test]
+#[allow(clippy::assertions_on_constants)]
+fn sanity_unclaimed_ratio() {
+    assert!(UNCLAIMED_NUMERATOR < UNCLAIMED_DENOMINATOR);
+    assert!(UNCLAIMED_NUMERATOR >= 0);
+    assert!(UNCLAIMED_DENOMINATOR > 0);
+}
+
+#[derive(Copy, Clone, Debug)]
+pub struct FlowControl {
+    /// Window the peer knows about.
+    ///
+    /// This can go negative if a SETTINGS_INITIAL_WINDOW_SIZE is received.
+    ///
+    /// For example, say the peer sends a request and uses 32kb of the window.
+    /// We send a SETTINGS_INITIAL_WINDOW_SIZE of 16kb. The peer has to adjust
+    /// its understanding of the capacity of the window, and that would be:
+    ///
+    /// ```notrust
+    /// default (64kb) - used (32kb) - settings_diff (64kb - 16kb): -16kb
+    /// ```
+    window_size: Window,
+
+    /// Window that we know about.
+    ///
+    /// This can go negative if a user declares a smaller target window than
+    /// the peer knows about.
+    available: Window,
+}
+
+impl FlowControl {
+    pub fn new() -> FlowControl {
+        FlowControl {
+            window_size: Window(0),
+            available: Window(0),
+        }
+    }
+
+    /// Returns the window size as known by the peer
+    pub fn window_size(&self) -> WindowSize {
+        self.window_size.as_size()
+    }
+
+    /// Returns the window size available to the consumer
+    pub fn available(&self) -> Window {
+        self.available
+    }
+
+    /// Returns true if there is unavailable window capacity
+    pub fn has_unavailable(&self) -> bool {
+        if self.window_size < 0 {
+            return false;
+        }
+
+        self.window_size > self.available
+    }
+
+    pub fn claim_capacity(&mut self, capacity: WindowSize) -> Result<(), Reason> {
+        self.available.decrease_by(capacity)
+    }
+
+    pub fn assign_capacity(&mut self, capacity: WindowSize) -> Result<(), Reason> {
+        self.available.increase_by(capacity)
+    }
+
+    /// If a WINDOW_UPDATE frame should be sent, returns a positive number
+    /// representing the increment to be used.
+    ///
+    /// If there is no available bytes to be reclaimed, or the number of
+    /// available bytes does not reach the threshold, this returns `None`.
+    ///
+    /// This represents pending outbound WINDOW_UPDATE frames.
+    pub fn unclaimed_capacity(&self) -> Option<WindowSize> {
+        let available = self.available;
+
+        if self.window_size >= available {
+            return None;
+        }
+
+        let unclaimed = available.0 - self.window_size.0;
+        let threshold = self.window_size.0 / UNCLAIMED_DENOMINATOR * UNCLAIMED_NUMERATOR;
+
+        if unclaimed < threshold {
+            None
+        } else {
+            Some(unclaimed as WindowSize)
+        }
+    }
+
+    /// Increase the window size.
+    ///
+    /// This is called after receiving a WINDOW_UPDATE frame
+    pub fn inc_window(&mut self, sz: WindowSize) -> Result<(), Reason> {
+        let (val, overflow) = self.window_size.0.overflowing_add(sz as i32);
+
+        if overflow {
+            return Err(Reason::FLOW_CONTROL_ERROR);
+        }
+
+        if val > MAX_WINDOW_SIZE as i32 {
+            return Err(Reason::FLOW_CONTROL_ERROR);
+        }
+
+        tracing::trace!(
+            "inc_window; sz={}; old={}; new={}",
+            sz,
+            self.window_size,
+            val
+        );
+
+        self.window_size = Window(val);
+        Ok(())
+    }
+
+    /// Decrement the send-side window size.
+    ///
+    /// This is called after receiving a SETTINGS frame with a lower
+    /// INITIAL_WINDOW_SIZE value.
+    pub fn dec_send_window(&mut self, sz: WindowSize) -> Result<(), Reason> {
+        tracing::trace!(
+            "dec_window; sz={}; window={}, available={}",
+            sz,
+            self.window_size,
+            self.available
+        );
+        // ~~This should not be able to overflow `window_size` from the bottom.~~ wrong. it can.
+        self.window_size.decrease_by(sz)?;
+        Ok(())
+    }
+
+    /// Decrement the recv-side window size.
+    ///
+    /// This is called after receiving a SETTINGS ACK frame with a lower
+    /// INITIAL_WINDOW_SIZE value.
+    pub fn dec_recv_window(&mut self, sz: WindowSize) -> Result<(), Reason> {
+        tracing::trace!(
+            "dec_recv_window; sz={}; window={}, available={}",
+            sz,
+            self.window_size,
+            self.available
+        );
+        // This should not be able to overflow `window_size` from the bottom.
+        self.window_size.decrease_by(sz)?;
+        self.available.decrease_by(sz)?;
+        Ok(())
+    }
+
+    /// Decrements the window reflecting data has actually been sent. The caller
+    /// must ensure that the window has capacity.
+    pub fn send_data(&mut self, sz: WindowSize) -> Result<(), Reason> {
+        tracing::trace!(
+            "send_data; sz={}; window={}; available={}",
+            sz,
+            self.window_size,
+            self.available
+        );
+
+        // If send size is zero it's meaningless to update flow control window
+        if sz > 0 {
+            // Ensure that the argument is correct
+            assert!(self.window_size.0 >= sz as i32);
+
+            // Update values
+            self.window_size.decrease_by(sz)?;
+            self.available.decrease_by(sz)?;
+        }
+        Ok(())
+    }
+}
+
+/// The current capacity of a flow-controlled Window.
+///
+/// This number can go negative when either side has used a certain amount
+/// of capacity when the other side advertises a reduction in size.
+///
+/// This type tries to centralize the knowledge of addition and subtraction
+/// to this capacity, instead of having integer casts throughout the source.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd)]
+pub struct Window(i32);
+
+impl Window {
+    pub fn as_size(&self) -> WindowSize {
+        if self.0 < 0 {
+            0
+        } else {
+            self.0 as WindowSize
+        }
+    }
+
+    pub fn checked_size(&self) -> WindowSize {
+        assert!(self.0 >= 0, "negative Window");
+        self.0 as WindowSize
+    }
+
+    pub fn decrease_by(&mut self, other: WindowSize) -> Result<(), Reason> {
+        if let Some(v) = self.0.checked_sub(other as i32) {
+            self.0 = v;
+            Ok(())
+        } else {
+            Err(Reason::FLOW_CONTROL_ERROR)
+        }
+    }
+
+    pub fn increase_by(&mut self, other: WindowSize) -> Result<(), Reason> {
+        let other = self.add(other)?;
+        self.0 = other.0;
+        Ok(())
+    }
+
+    pub fn add(&self, other: WindowSize) -> Result<Self, Reason> {
+        if let Some(v) = self.0.checked_add(other as i32) {
+            Ok(Self(v))
+        } else {
+            Err(Reason::FLOW_CONTROL_ERROR)
+        }
+    }
+}
+
+impl PartialEq<usize> for Window {
+    fn eq(&self, other: &usize) -> bool {
+        if self.0 < 0 {
+            false
+        } else {
+            (self.0 as usize).eq(other)
+        }
+    }
+}
+
+impl PartialOrd<usize> for Window {
+    fn partial_cmp(&self, other: &usize) -> Option<::std::cmp::Ordering> {
+        if self.0 < 0 {
+            Some(::std::cmp::Ordering::Less)
+        } else {
+            (self.0 as usize).partial_cmp(other)
+        }
+    }
+}
+
+impl fmt::Display for Window {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Display::fmt(&self.0, f)
+    }
+}
+
+impl From<Window> for isize {
+    fn from(w: Window) -> isize {
+        w.0 as isize
+    }
+}

vendor/h2/src/proto/streams/mod.rs

@@ -0,0 +1,128 @@
+mod buffer;
+mod counts;
+mod flow_control;
+mod prioritize;
+mod recv;
+mod send;
+mod state;
+mod store;
+mod stream;
+#[allow(clippy::module_inception)]
+mod streams;
+
+pub(crate) use self::prioritize::Prioritized;
+pub(crate) use self::recv::Open;
+pub(crate) use self::send::PollReset;
+pub(crate) use self::streams::{DynStreams, OpaqueStreamRef, StreamRef, Streams};
+
+use self::buffer::Buffer;
+use self::counts::Counts;
+use self::flow_control::FlowControl;
+use self::prioritize::Prioritize;
+use self::recv::Recv;
+use self::send::Send;
+use self::state::State;
+use self::store::Store;
+use self::stream::Stream;
+
+use crate::frame::{StreamId, StreamIdOverflow};
+use crate::proto::*;
+
+use bytes::Bytes;
+use std::time::Duration;
+
+#[derive(Debug)]
+pub struct Config {
+    /// Initial maximum number of locally initiated streams.
+    /// After receiving a Settings frame from the remote peer,
+    /// the connection will overwrite this value with the
+    /// MAX_CONCURRENT_STREAMS specified in the frame.
+    pub initial_max_send_streams: usize,
+
+    /// Max amount of DATA bytes to buffer per stream.
+    pub local_max_buffer_size: usize,
+
+    /// The stream ID to start the next local stream with
+    pub local_next_stream_id: StreamId,
+
+    /// If the local peer is willing to receive push promises
+    pub local_push_enabled: bool,
+
+    /// If extended connect protocol is enabled.
+    pub extended_connect_protocol_enabled: bool,
+
+    /// How long a locally reset stream should ignore frames
+    pub local_reset_duration: Duration,
+
+    /// Maximum number of locally reset streams to keep at a time
+    pub local_reset_max: usize,
+
+    /// Maximum number of remotely reset "pending accept" streams to keep at a
+    /// time. Going over this number results in a connection error.
+    pub remote_reset_max: usize,
+
+    /// Initial window size of remote initiated streams
+    pub remote_init_window_sz: WindowSize,
+
+    /// Maximum number of remote initiated streams
+    pub remote_max_initiated: Option<usize>,
+
+    /// Maximum number of locally reset streams due to protocol error across
+    /// the lifetime of the connection.
+    ///
+    /// When this gets exceeded, we issue GOAWAYs.
+    pub local_max_error_reset_streams: Option<usize>,
+}
+
+trait DebugStructExt<'a, 'b> {
+    // h2_ prefixes to protect against possible future name collisions
+    fn h2_field_if(&mut self, name: &str, val: &bool) -> &mut std::fmt::DebugStruct<'a, 'b>;
+
+    fn h2_field_if_then<T: std::fmt::Debug>(
+        &mut self,
+        name: &str,
+        cond: bool,
+        val: &T,
+    ) -> &mut std::fmt::DebugStruct<'a, 'b>;
+
+    fn h2_field_some<T: std::fmt::Debug>(
+        &mut self,
+        name: &str,
+        val: &Option<T>,
+    ) -> &mut std::fmt::DebugStruct<'a, 'b>;
+}
+
+impl<'a, 'b> DebugStructExt<'a, 'b> for std::fmt::DebugStruct<'a, 'b> {
+    fn h2_field_if(&mut self, name: &str, val: &bool) -> &mut std::fmt::DebugStruct<'a, 'b> {
+        if *val {
+            self.field(name, val)
+        } else {
+            self
+        }
+    }
+
+    fn h2_field_if_then<T: std::fmt::Debug>(
+        &mut self,
+        name: &str,
+        cond: bool,
+        val: &T,
+    ) -> &mut std::fmt::DebugStruct<'a, 'b> {
+        if cond {
+            self.field(name, val)
+        } else {
+            self
+        }
+    }
+
+    fn h2_field_some<T: std::fmt::Debug>(
+        &mut self,
+        name: &str,
+        val: &Option<T>,
+    ) -> &mut std::fmt::DebugStruct<'a, 'b> {
+        if val.is_some() {
+            self.field(name, val)
+        } else {
+            self
+        }
+    }
+}

vendor/h2/src/proto/streams/prioritize.rs

@@ -0,0 +1,945 @@
+use super::store::Resolve;
+use super::*;
+
+use crate::frame::Reason;
+
+use crate::codec::UserError;
+use crate::codec::UserError::*;
+
+use bytes::buf::Take;
+use std::{
+    cmp::{self, Ordering},
+    fmt, io, mem,
+    task::{Context, Poll, Waker},
+};
+
+/// # Warning
+///
+/// Queued streams are ordered by stream ID, as we need to ensure that
+/// lower-numbered streams are sent headers before higher-numbered ones.
+/// This is because "idle" stream IDs – those which have been initiated but
+/// have yet to receive frames – will be implicitly closed on receipt of a
+/// frame on a higher stream ID. If these queues was not ordered by stream
+/// IDs, some mechanism would be necessary to ensure that the lowest-numbered]
+/// idle stream is opened first.
+#[derive(Debug)]
+pub(super) struct Prioritize {
+    /// Queue of streams waiting for socket capacity to send a frame.
+    pending_send: store::Queue<stream::NextSend>,
+
+    /// Queue of streams waiting for window capacity to produce data.
+    pending_capacity: store::Queue<stream::NextSendCapacity>,
+
+    /// Streams waiting for capacity due to max concurrency
+    ///
+    /// The `SendRequest` handle is `Clone`. This enables initiating requests
+    /// from many tasks. However, offering this capability while supporting
+    /// backpressure at some level is tricky. If there are many `SendRequest`
+    /// handles and a single stream becomes available, which handle gets
+    /// assigned that stream? Maybe that handle is no longer ready to send a
+    /// request.
+    ///
+    /// The strategy used is to allow each `SendRequest` handle one buffered
+    /// request. A `SendRequest` handle is ready to send a request if it has no
+    /// associated buffered requests. This is the same strategy as `mpsc` in the
+    /// futures library.
+    pending_open: store::Queue<stream::NextOpen>,
+
+    /// Connection level flow control governing sent data
+    flow: FlowControl,
+
+    /// Stream ID of the last stream opened.
+    last_opened_id: StreamId,
+
+    /// What `DATA` frame is currently being sent in the codec.
+    in_flight_data_frame: InFlightData,
+
+    /// The maximum amount of bytes a stream should buffer.
+    max_buffer_size: usize,
+}
+
+#[derive(Debug, Eq, PartialEq)]
+enum InFlightData {
+    /// There is no `DATA` frame in flight.
+    Nothing,
+    /// There is a `DATA` frame in flight belonging to the given stream.
+    DataFrame(store::Key),
+    /// There was a `DATA` frame, but the stream's queue was since cleared.
+    Drop,
+}
+
+pub(crate) struct Prioritized<B> {
+    // The buffer
+    inner: Take<B>,
+
+    end_of_stream: bool,
+
+    // The stream that this is associated with
+    stream: store::Key,
+}
+
+// ===== impl Prioritize =====
+
+impl Prioritize {
+    pub fn new(config: &Config) -> Prioritize {
+        let mut flow = FlowControl::new();
+
+        flow.inc_window(config.remote_init_window_sz)
+            .expect("invalid initial window size");
+
+        // TODO: proper error handling
+        let _res = flow.assign_capacity(config.remote_init_window_sz);
+        debug_assert!(_res.is_ok());
+
+        tracing::trace!("Prioritize::new; flow={:?}", flow);
+
+        Prioritize {
+            pending_send: store::Queue::new(),
+            pending_capacity: store::Queue::new(),
+            pending_open: store::Queue::new(),
+            flow,
+            last_opened_id: StreamId::ZERO,
+            in_flight_data_frame: InFlightData::Nothing,
+            max_buffer_size: config.local_max_buffer_size,
+        }
+    }
+
+    pub(crate) fn max_buffer_size(&self) -> usize {
+        self.max_buffer_size
+    }
+
+    /// Queue a frame to be sent to the remote
+    pub fn queue_frame<B>(
+        &mut self,
+        frame: Frame<B>,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        task: &mut Option<Waker>,
+    ) {
+        let span = tracing::trace_span!("Prioritize::queue_frame", ?stream.id);
+        let _e = span.enter();
+        // Queue the frame in the buffer
+        stream.pending_send.push_back(buffer, frame);
+        self.schedule_send(stream, task);
+    }
+
+    pub fn schedule_send(&mut self, stream: &mut store::Ptr, task: &mut Option<Waker>) {
+        // If the stream is waiting to be opened, nothing more to do.
+        if stream.is_send_ready() {
+            tracing::trace!(?stream.id, "schedule_send");
+            // Queue the stream
+            self.pending_send.push(stream);
+
+            // Notify the connection.
+            if let Some(task) = task.take() {
+                task.wake();
+            }
+        }
+    }
+
+    pub fn queue_open(&mut self, stream: &mut store::Ptr) {
+        self.pending_open.push(stream);
+    }
+
+    /// Send a data frame
+    pub fn send_data<B>(
+        &mut self,
+        frame: frame::Data<B>,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), UserError>
+    where
+        B: Buf,
+    {
+        let sz = frame.payload().remaining();
+
+        if sz > MAX_WINDOW_SIZE as usize {
+            return Err(UserError::PayloadTooBig);
+        }
+
+        let sz = sz as WindowSize;
+
+        if !stream.state.is_send_streaming() {
+            if stream.state.is_closed() {
+                return Err(InactiveStreamId);
+            } else {
+                return Err(UnexpectedFrameType);
+            }
+        }
+
+        // Update the buffered data counter
+        stream.buffered_send_data += sz as usize;
+
+        let span =
+            tracing::trace_span!("send_data", sz, requested = stream.requested_send_capacity);
+        let _e = span.enter();
+        tracing::trace!(buffered = stream.buffered_send_data);
+
+        // Implicitly request more send capacity if not enough has been
+        // requested yet.
+        if (stream.requested_send_capacity as usize) < stream.buffered_send_data {
+            // Update the target requested capacity
+            stream.requested_send_capacity =
+                cmp::min(stream.buffered_send_data, WindowSize::MAX as usize) as WindowSize;
+
+            // `try_assign_capacity` will queue the stream to `pending_capacity` if the capcaity
+            // cannot be assigned at the time it is called.
+            self.try_assign_capacity(stream);
+        }
+
+        if frame.is_end_stream() {
+            stream.state.send_close();
+            self.reserve_capacity(0, stream, counts);
+        }
+
+        tracing::trace!(
+            available = %stream.send_flow.available(),
+            buffered = stream.buffered_send_data,
+        );
+
+        // The `stream.buffered_send_data == 0` check is here so that, if a zero
+        // length data frame is queued to the front (there is no previously
+        // queued data), it gets sent out immediately even if there is no
+        // available send window.
+        //
+        // Sending out zero length data frames can be done to signal
+        // end-of-stream.
+        //
+        if stream.send_flow.available() > 0 || stream.buffered_send_data == 0 {
+            // The stream currently has capacity to send the data frame, so
+            // queue it up and notify the connection task.
+            self.queue_frame(frame.into(), buffer, stream, task);
+        } else {
+            // The stream has no capacity to send the frame now, save it but
+            // don't notify the connection task. Once additional capacity
+            // becomes available, the frame will be flushed.
+            stream.pending_send.push_back(buffer, frame.into());
+        }
+
+        Ok(())
+    }
+
+    /// Request capacity to send data
+    pub fn reserve_capacity(
+        &mut self,
+        capacity: WindowSize,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+    ) {
+        let span = tracing::trace_span!(
+            "reserve_capacity",
+            ?stream.id,
+            requested = capacity,
+            effective = (capacity as usize) + stream.buffered_send_data,
+            curr = stream.requested_send_capacity
+        );
+        let _e = span.enter();
+
+        // Actual capacity is `capacity` + the current amount of buffered data.
+        // If it were less, then we could never send out the buffered data.
+        let capacity = (capacity as usize) + stream.buffered_send_data;
+
+        match capacity.cmp(&(stream.requested_send_capacity as usize)) {
+            Ordering::Equal => {
+                // Nothing to do
+            }
+            Ordering::Less => {
+                // Update the target requested capacity
+                stream.requested_send_capacity = capacity as WindowSize;
+
+                // Currently available capacity assigned to the stream
+                let available = stream.send_flow.available().as_size();
+
+                // If the stream has more assigned capacity than requested, reclaim
+                // some for the connection
+                if available as usize > capacity {
+                    let diff = available - capacity as WindowSize;
+
+                    // TODO: proper error handling
+                    let _res = stream.send_flow.claim_capacity(diff);
+                    debug_assert!(_res.is_ok());
+
+                    self.assign_connection_capacity(diff, stream, counts);
+                }
+            }
+            Ordering::Greater => {
+                // If trying to *add* capacity, but the stream send side is closed,
+                // there's nothing to be done.
+                if stream.state.is_send_closed() {
+                    return;
+                }
+
+                // Update the target requested capacity
+                stream.requested_send_capacity =
+                    cmp::min(capacity, WindowSize::MAX as usize) as WindowSize;
+
+                // Try to assign additional capacity to the stream. If none is
+                // currently available, the stream will be queued to receive some
+                // when more becomes available.
+                self.try_assign_capacity(stream);
+            }
+        }
+    }
+
+    pub fn recv_stream_window_update(
+        &mut self,
+        inc: WindowSize,
+        stream: &mut store::Ptr,
+    ) -> Result<(), Reason> {
+        let span = tracing::trace_span!(
+            "recv_stream_window_update",
+            ?stream.id,
+            ?stream.state,
+            inc,
+            flow = ?stream.send_flow
+        );
+        let _e = span.enter();
+
+        if stream.state.is_send_closed() && stream.buffered_send_data == 0 {
+            // We can't send any data, so don't bother doing anything else.
+            return Ok(());
+        }
+
+        // Update the stream level flow control.
+        stream.send_flow.inc_window(inc)?;
+
+        // If the stream is waiting on additional capacity, then this will
+        // assign it (if available on the connection) and notify the producer
+        self.try_assign_capacity(stream);
+
+        Ok(())
+    }
+
+    pub fn recv_connection_window_update(
+        &mut self,
+        inc: WindowSize,
+        store: &mut Store,
+        counts: &mut Counts,
+    ) -> Result<(), Reason> {
+        // Update the connection's window
+        self.flow.inc_window(inc)?;
+
+        self.assign_connection_capacity(inc, store, counts);
+        Ok(())
+    }
+
+    /// Reclaim all capacity assigned to the stream and re-assign it to the
+    /// connection
+    pub fn reclaim_all_capacity(&mut self, stream: &mut store::Ptr, counts: &mut Counts) {
+        let available = stream.send_flow.available().as_size();
+        if available > 0 {
+            // TODO: proper error handling
+            let _res = stream.send_flow.claim_capacity(available);
+            debug_assert!(_res.is_ok());
+            // Re-assign all capacity to the connection
+            self.assign_connection_capacity(available, stream, counts);
+        }
+    }
+
+    /// Reclaim just reserved capacity, not buffered capacity, and re-assign
+    /// it to the connection
+    pub fn reclaim_reserved_capacity(&mut self, stream: &mut store::Ptr, counts: &mut Counts) {
+        // only reclaim reserved capacity that isn't already buffered
+        if stream.send_flow.available().as_size() as usize > stream.buffered_send_data {
+            let reserved =
+                stream.send_flow.available().as_size() - stream.buffered_send_data as WindowSize;
+
+            // Panic safety: due to how `reserved` is computed it can't be greater
+            // than what's available.
+            stream
+                .send_flow
+                .claim_capacity(reserved)
+                .expect("window size should be greater than reserved");
+
+            self.assign_connection_capacity(reserved, stream, counts);
+        }
+    }
+
+    pub fn clear_pending_capacity(&mut self, store: &mut Store, counts: &mut Counts) {
+        let span = tracing::trace_span!("clear_pending_capacity");
+        let _e = span.enter();
+        while let Some(stream) = self.pending_capacity.pop(store) {
+            counts.transition(stream, |_, stream| {
+                tracing::trace!(?stream.id, "clear_pending_capacity");
+            })
+        }
+    }
+
+    pub fn assign_connection_capacity<R>(
+        &mut self,
+        inc: WindowSize,
+        store: &mut R,
+        counts: &mut Counts,
+    ) where
+        R: Resolve,
+    {
+        let span = tracing::trace_span!("assign_connection_capacity", inc);
+        let _e = span.enter();
+
+        // TODO: proper error handling
+        let _res = self.flow.assign_capacity(inc);
+        debug_assert!(_res.is_ok());
+
+        // Assign newly acquired capacity to streams pending capacity.
+        while self.flow.available() > 0 {
+            let stream = match self.pending_capacity.pop(store) {
+                Some(stream) => stream,
+                None => return,
+            };
+
+            // Streams pending capacity may have been reset before capacity
+            // became available. In that case, the stream won't want any
+            // capacity, and so we shouldn't "transition" on it, but just evict
+            // it and continue the loop.
+            if !(stream.state.is_send_streaming() || stream.buffered_send_data > 0) {
+                continue;
+            }
+
+            counts.transition(stream, |_, stream| {
+                // Try to assign capacity to the stream. This will also re-queue the
+                // stream if there isn't enough connection level capacity to fulfill
+                // the capacity request.
+                self.try_assign_capacity(stream);
+            })
+        }
+    }
+
+    /// Request capacity to send data
+    fn try_assign_capacity(&mut self, stream: &mut store::Ptr) {
+        // Streams over the max concurrent count should not have capacity assign to avoid starving the connection
+        // capacity for open streams
+        if stream.is_pending_open {
+            return;
+        }
+
+        let total_requested = stream.requested_send_capacity;
+
+        // Total requested should never go below actual assigned
+        // (Note: the window size can go lower than assigned)
+        debug_assert!(stream.send_flow.available() <= total_requested as usize);
+
+        // The amount of additional capacity that the stream requests.
+        // Don't assign more than the window has available!
+        let additional = cmp::min(
+            total_requested - stream.send_flow.available().as_size(),
+            // Can't assign more than what is available
+            stream.send_flow.window_size() - stream.send_flow.available().as_size(),
+        );
+        let span = tracing::trace_span!("try_assign_capacity", ?stream.id);
+        let _e = span.enter();
+        tracing::trace!(
+            requested = total_requested,
+            additional,
+            buffered = stream.buffered_send_data,
+            window = stream.send_flow.window_size(),
+            conn = %self.flow.available()
+        );
+
+        if additional == 0 {
+            // Nothing more to do
+            return;
+        }
+
+        // If the stream has requested capacity, then it must be in the
+        // streaming state (more data could be sent) or there is buffered data
+        // waiting to be sent.
+        debug_assert!(
+            stream.state.is_send_streaming() || stream.buffered_send_data > 0,
+            "state={:?}",
+            stream.state
+        );
+
+        // The amount of currently available capacity on the connection
+        let conn_available = self.flow.available().as_size();
+
+        // First check if capacity is immediately available
+        if conn_available > 0 {
+            // The amount of capacity to assign to the stream
+            // TODO: Should prioritization factor into this?
+            let assign = cmp::min(conn_available, additional);
+
+            tracing::trace!(capacity = assign, "assigning");
+
+            // Assign the capacity to the stream
+            stream.assign_capacity(assign, self.max_buffer_size);
+
+            // Claim the capacity from the connection
+            // TODO: proper error handling
+            let _res = self.flow.claim_capacity(assign);
+            debug_assert!(_res.is_ok());
+        }
+
+        tracing::trace!(
+            available = %stream.send_flow.available(),
+            requested = stream.requested_send_capacity,
+            buffered = stream.buffered_send_data,
+            has_unavailable = %stream.send_flow.has_unavailable()
+        );
+
+        if stream.send_flow.available() < stream.requested_send_capacity as usize
+            && stream.send_flow.has_unavailable()
+        {
+            // The stream requires additional capacity and the stream's
+            // window has available capacity, but the connection window
+            // does not.
+            //
+            // In this case, the stream needs to be queued up for when the
+            // connection has more capacity.
+            self.pending_capacity.push(stream);
+        }
+
+        // If data is buffered and the stream is send ready, then
+        // schedule the stream for execution
+        if stream.buffered_send_data > 0 && stream.is_send_ready() {
+            // TODO: This assertion isn't *exactly* correct. There can still be
+            // buffered send data while the stream's pending send queue is
+            // empty. This can happen when a large data frame is in the process
+            // of being **partially** sent. Once the window has been sent, the
+            // data frame will be returned to the prioritization layer to be
+            // re-scheduled.
+            //
+            // That said, it would be nice to figure out how to make this
+            // assertion correctly.
+            //
+            // debug_assert!(!stream.pending_send.is_empty());
+
+            self.pending_send.push(stream);
+        }
+    }
+
+    pub fn poll_complete<T, B>(
+        &mut self,
+        cx: &mut Context,
+        buffer: &mut Buffer<Frame<B>>,
+        store: &mut Store,
+        counts: &mut Counts,
+        dst: &mut Codec<T, Prioritized<B>>,
+    ) -> Poll<io::Result<()>>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+    {
+        // Ensure codec is ready
+        ready!(dst.poll_ready(cx))?;
+
+        // Reclaim any frame that has previously been written
+        self.reclaim_frame(buffer, store, dst);
+
+        // The max frame length
+        let max_frame_len = dst.max_send_frame_size();
+
+        tracing::trace!("poll_complete");
+
+        loop {
+            if let Some(mut stream) = self.pop_pending_open(store, counts) {
+                self.pending_send.push_front(&mut stream);
+                self.try_assign_capacity(&mut stream);
+            }
+
+            match self.pop_frame(buffer, store, max_frame_len, counts) {
+                Some(frame) => {
+                    tracing::trace!(?frame, "writing");
+
+                    debug_assert_eq!(self.in_flight_data_frame, InFlightData::Nothing);
+                    if let Frame::Data(ref frame) = frame {
+                        self.in_flight_data_frame = InFlightData::DataFrame(frame.payload().stream);
+                    }
+                    dst.buffer(frame).expect("invalid frame");
+
+                    // Ensure the codec is ready to try the loop again.
+                    ready!(dst.poll_ready(cx))?;
+
+                    // Because, always try to reclaim...
+                    self.reclaim_frame(buffer, store, dst);
+                }
+                None => {
+                    // Try to flush the codec.
+                    ready!(dst.flush(cx))?;
+
+                    // This might release a data frame...
+                    if !self.reclaim_frame(buffer, store, dst) {
+                        return Poll::Ready(Ok(()));
+                    }
+
+                    // No need to poll ready as poll_complete() does this for
+                    // us...
+                }
+            }
+        }
+    }
+
+    /// Tries to reclaim a pending data frame from the codec.
+    ///
+    /// Returns true if a frame was reclaimed.
+    ///
+    /// When a data frame is written to the codec, it may not be written in its
+    /// entirety (large chunks are split up into potentially many data frames).
+    /// In this case, the stream needs to be reprioritized.
+    fn reclaim_frame<T, B>(
+        &mut self,
+        buffer: &mut Buffer<Frame<B>>,
+        store: &mut Store,
+        dst: &mut Codec<T, Prioritized<B>>,
+    ) -> bool
+    where
+        B: Buf,
+    {
+        let span = tracing::trace_span!("try_reclaim_frame");
+        let _e = span.enter();
+
+        // First check if there are any data chunks to take back
+        if let Some(frame) = dst.take_last_data_frame() {
+            self.reclaim_frame_inner(buffer, store, frame)
+        } else {
+            false
+        }
+    }
+
+    fn reclaim_frame_inner<B>(
+        &mut self,
+        buffer: &mut Buffer<Frame<B>>,
+        store: &mut Store,
+        frame: frame::Data<Prioritized<B>>,
+    ) -> bool
+    where
+        B: Buf,
+    {
+        tracing::trace!(
+            ?frame,
+            sz = frame.payload().inner.get_ref().remaining(),
+            "reclaimed"
+        );
+
+        let mut eos = false;
+        let key = frame.payload().stream;
+
+        match mem::replace(&mut self.in_flight_data_frame, InFlightData::Nothing) {
+            InFlightData::Nothing => panic!("wasn't expecting a frame to reclaim"),
+            InFlightData::Drop => {
+                tracing::trace!("not reclaiming frame for cancelled stream");
+                return false;
+            }
+            InFlightData::DataFrame(k) => {
+                debug_assert_eq!(k, key);
+            }
+        }
+
+        let mut frame = frame.map(|prioritized| {
+            // TODO: Ensure fully written
+            eos = prioritized.end_of_stream;
+            prioritized.inner.into_inner()
+        });
+
+        if frame.payload().has_remaining() {
+            let mut stream = store.resolve(key);
+
+            if eos {
+                frame.set_end_stream(true);
+            }
+
+            self.push_back_frame(frame.into(), buffer, &mut stream);
+
+            return true;
+        }
+
+        false
+    }
+
+    /// Push the frame to the front of the stream's deque, scheduling the
+    /// stream if needed.
+    fn push_back_frame<B>(
+        &mut self,
+        frame: Frame<B>,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+    ) {
+        // Push the frame to the front of the stream's deque
+        stream.pending_send.push_front(buffer, frame);
+
+        // If needed, schedule the sender
+        if stream.send_flow.available() > 0 {
+            debug_assert!(!stream.pending_send.is_empty());
+            self.pending_send.push(stream);
+        }
+    }
+
+    pub fn clear_queue<B>(&mut self, buffer: &mut Buffer<Frame<B>>, stream: &mut store::Ptr) {
+        let span = tracing::trace_span!("clear_queue", ?stream.id);
+        let _e = span.enter();
+
+        // TODO: make this more efficient?
+        while let Some(frame) = stream.pending_send.pop_front(buffer) {
+            tracing::trace!(?frame, "dropping");
+        }
+
+        stream.buffered_send_data = 0;
+        stream.requested_send_capacity = 0;
+        if let InFlightData::DataFrame(key) = self.in_flight_data_frame {
+            if stream.key() == key {
+                // This stream could get cleaned up now - don't allow the buffered frame to get reclaimed.
+                self.in_flight_data_frame = InFlightData::Drop;
+            }
+        }
+    }
+
+    pub fn clear_pending_send(&mut self, store: &mut Store, counts: &mut Counts) {
+        while let Some(mut stream) = self.pending_send.pop(store) {
+            let is_pending_reset = stream.is_pending_reset_expiration();
+            if let Some(reason) = stream.state.get_scheduled_reset() {
+                stream.set_reset(reason, Initiator::Library);
+            }
+            counts.transition_after(stream, is_pending_reset);
+        }
+    }
+
+    pub fn clear_pending_open(&mut self, store: &mut Store, counts: &mut Counts) {
+        while let Some(stream) = self.pending_open.pop(store) {
+            let is_pending_reset = stream.is_pending_reset_expiration();
+            counts.transition_after(stream, is_pending_reset);
+        }
+    }
+
+    fn pop_frame<B>(
+        &mut self,
+        buffer: &mut Buffer<Frame<B>>,
+        store: &mut Store,
+        max_len: usize,
+        counts: &mut Counts,
+    ) -> Option<Frame<Prioritized<B>>>
+    where
+        B: Buf,
+    {
+        let span = tracing::trace_span!("pop_frame");
+        let _e = span.enter();
+
+        loop {
+            match self.pending_send.pop(store) {
+                Some(mut stream) => {
+                    let span = tracing::trace_span!("popped", ?stream.id, ?stream.state);
+                    let _e = span.enter();
+
+                    // It's possible that this stream, besides having data to send,
+                    // is also queued to send a reset, and thus is already in the queue
+                    // to wait for "some time" after a reset.
+                    //
+                    // To be safe, we just always ask the stream.
+                    let is_pending_reset = stream.is_pending_reset_expiration();
+
+                    tracing::trace!(is_pending_reset);
+
+                    let frame = match stream.pending_send.pop_front(buffer) {
+                        Some(Frame::Data(mut frame)) => {
+                            // Get the amount of capacity remaining for stream's
+                            // window.
+                            let stream_capacity = stream.send_flow.available();
+                            let sz = frame.payload().remaining();
+
+                            tracing::trace!(
+                                sz,
+                                eos = frame.is_end_stream(),
+                                window = %stream_capacity,
+                                available = %stream.send_flow.available(),
+                                requested = stream.requested_send_capacity,
+                                buffered = stream.buffered_send_data,
+                                "data frame"
+                            );
+
+                            // Zero length data frames always have capacity to
+                            // be sent.
+                            if sz > 0 && stream_capacity == 0 {
+                                tracing::trace!("stream capacity is 0");
+
+                                // Ensure that the stream is waiting for
+                                // connection level capacity
+                                //
+                                // TODO: uncomment
+                                // debug_assert!(stream.is_pending_send_capacity);
+
+                                // The stream has no more capacity, this can
+                                // happen if the remote reduced the stream
+                                // window. In this case, we need to buffer the
+                                // frame and wait for a window update...
+                                stream.pending_send.push_front(buffer, frame.into());
+
+                                continue;
+                            }
+
+                            // Only send up to the max frame length
+                            let len = cmp::min(sz, max_len);
+
+                            // Only send up to the stream's window capacity
+                            let len =
+                                cmp::min(len, stream_capacity.as_size() as usize) as WindowSize;
+
+                            // There *must* be be enough connection level
+                            // capacity at this point.
+                            debug_assert!(len <= self.flow.window_size());
+
+                            // Check if the stream level window the peer knows is available. In some
+                            // scenarios, maybe the window we know is available but the window which
+                            // peer knows is not.
+                            if len > 0 && len > stream.send_flow.window_size() {
+                                stream.pending_send.push_front(buffer, frame.into());
+                                continue;
+                            }
+
+                            tracing::trace!(len, "sending data frame");
+
+                            // Update the flow control
+                            tracing::trace_span!("updating stream flow").in_scope(|| {
+                                stream.send_data(len, self.max_buffer_size);
+
+                                // Assign the capacity back to the connection that
+                                // was just consumed from the stream in the previous
+                                // line.
+                                // TODO: proper error handling
+                                let _res = self.flow.assign_capacity(len);
+                                debug_assert!(_res.is_ok());
+                            });
+
+                            let (eos, len) = tracing::trace_span!("updating connection flow")
+                                .in_scope(|| {
+                                    // TODO: proper error handling
+                                    let _res = self.flow.send_data(len);
+                                    debug_assert!(_res.is_ok());
+
+                                    // Wrap the frame's data payload to ensure that the
+                                    // correct amount of data gets written.
+
+                                    let eos = frame.is_end_stream();
+                                    let len = len as usize;
+
+                                    if frame.payload().remaining() > len {
+                                        frame.set_end_stream(false);
+                                    }
+                                    (eos, len)
+                                });
+
+                            Frame::Data(frame.map(|buf| Prioritized {
+                                inner: buf.take(len),
+                                end_of_stream: eos,
+                                stream: stream.key(),
+                            }))
+                        }
+                        Some(Frame::PushPromise(pp)) => {
+                            let mut pushed =
+                                stream.store_mut().find_mut(&pp.promised_id()).unwrap();
+                            pushed.is_pending_push = false;
+                            // Transition stream from pending_push to pending_open
+                            // if possible
+                            if !pushed.pending_send.is_empty() {
+                                if counts.can_inc_num_send_streams() {
+                                    counts.inc_num_send_streams(&mut pushed);
+                                    self.pending_send.push(&mut pushed);
+                                } else {
+                                    self.queue_open(&mut pushed);
+                                }
+                            }
+                            Frame::PushPromise(pp)
+                        }
+                        Some(frame) => frame.map(|_| {
+                            unreachable!(
+                                "Frame::map closure will only be called \
+                                 on DATA frames."
+                            )
+                        }),
+                        None => {
+                            if let Some(reason) = stream.state.get_scheduled_reset() {
+                                stream.set_reset(reason, Initiator::Library);
+
+                                let frame = frame::Reset::new(stream.id, reason);
+                                Frame::Reset(frame)
+                            } else {
+                                // If the stream receives a RESET from the peer, it may have
+                                // had data buffered to be sent, but all the frames are cleared
+                                // in clear_queue(). Instead of doing O(N) traversal through queue
+                                // to remove, lets just ignore the stream here.
+                                tracing::trace!("removing dangling stream from pending_send");
+                                // Since this should only happen as a consequence of `clear_queue`,
+                                // we must be in a closed state of some kind.
+                                debug_assert!(stream.state.is_closed());
+                                counts.transition_after(stream, is_pending_reset);
+                                continue;
+                            }
+                        }
+                    };
+
+                    tracing::trace!("pop_frame; frame={:?}", frame);
+
+                    if cfg!(debug_assertions) && stream.state.is_idle() {
+                        debug_assert!(stream.id > self.last_opened_id);
+                        self.last_opened_id = stream.id;
+                    }
+
+                    if !stream.pending_send.is_empty() || stream.state.is_scheduled_reset() {
+                        // TODO: Only requeue the sender IF it is ready to send
+                        // the next frame. i.e. don't requeue it if the next
+                        // frame is a data frame and the stream does not have
+                        // any more capacity.
+                        self.pending_send.push(&mut stream);
+                    }
+
+                    counts.transition_after(stream, is_pending_reset);
+
+                    return Some(frame);
+                }
+                None => return None,
+            }
+        }
+    }
+
+    fn pop_pending_open<'s>(
+        &mut self,
+        store: &'s mut Store,
+        counts: &mut Counts,
+    ) -> Option<store::Ptr<'s>> {
+        tracing::trace!("schedule_pending_open");
+        // check for any pending open streams
+        if counts.can_inc_num_send_streams() {
+            if let Some(mut stream) = self.pending_open.pop(store) {
+                tracing::trace!("schedule_pending_open; stream={:?}", stream.id);
+
+                counts.inc_num_send_streams(&mut stream);
+                stream.notify_send();
+                return Some(stream);
+            }
+        }
+
+        None
+    }
+}
+
+// ===== impl Prioritized =====
+
+impl<B> Buf for Prioritized<B>
+where
+    B: Buf,
+{
+    fn remaining(&self) -> usize {
+        self.inner.remaining()
+    }
+
+    fn chunk(&self) -> &[u8] {
+        self.inner.chunk()
+    }
+
+    fn chunks_vectored<'a>(&'a self, dst: &mut [std::io::IoSlice<'a>]) -> usize {
+        self.inner.chunks_vectored(dst)
+    }
+
+    fn advance(&mut self, cnt: usize) {
+        self.inner.advance(cnt)
+    }
+}
+
+impl<B: Buf> fmt::Debug for Prioritized<B> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.debug_struct("Prioritized")
+            .field("remaining", &self.inner.get_ref().remaining())
+            .field("end_of_stream", &self.end_of_stream)
+            .field("stream", &self.stream)
+            .finish()
+    }
+}

vendor/h2/src/proto/streams/send.rs

@@ -0,0 +1,627 @@
+use super::{
+    store, Buffer, Codec, Config, Counts, Frame, Prioritize, Prioritized, Store, Stream, StreamId,
+    StreamIdOverflow, WindowSize,
+};
+use crate::codec::UserError;
+use crate::frame::{self, Reason};
+use crate::proto::{self, Error, Initiator};
+
+use bytes::Buf;
+use tokio::io::AsyncWrite;
+
+use std::cmp::Ordering;
+use std::io;
+use std::task::{Context, Poll, Waker};
+
+/// Manages state transitions related to outbound frames.
+#[derive(Debug)]
+pub(super) struct Send {
+    /// Stream identifier to use for next initialized stream.
+    next_stream_id: Result<StreamId, StreamIdOverflow>,
+
+    /// Any streams with a higher ID are ignored.
+    ///
+    /// This starts as MAX, but is lowered when a GOAWAY is received.
+    ///
+    /// > After sending a GOAWAY frame, the sender can discard frames for
+    /// > streams initiated by the receiver with identifiers higher than
+    /// > the identified last stream.
+    max_stream_id: StreamId,
+
+    /// Initial window size of locally initiated streams
+    init_window_sz: WindowSize,
+
+    /// Prioritization layer
+    prioritize: Prioritize,
+
+    is_push_enabled: bool,
+
+    /// If extended connect protocol is enabled.
+    is_extended_connect_protocol_enabled: bool,
+}
+
+/// A value to detect which public API has called `poll_reset`.
+#[derive(Debug)]
+pub(crate) enum PollReset {
+    AwaitingHeaders,
+    Streaming,
+}
+
+impl Send {
+    /// Create a new `Send`
+    pub fn new(config: &Config) -> Self {
+        Send {
+            init_window_sz: config.remote_init_window_sz,
+            max_stream_id: StreamId::MAX,
+            next_stream_id: Ok(config.local_next_stream_id),
+            prioritize: Prioritize::new(config),
+            is_push_enabled: true,
+            is_extended_connect_protocol_enabled: false,
+        }
+    }
+
+    /// Returns the initial send window size
+    pub fn init_window_sz(&self) -> WindowSize {
+        self.init_window_sz
+    }
+
+    pub fn open(&mut self) -> Result<StreamId, UserError> {
+        let stream_id = self.ensure_next_stream_id()?;
+        self.next_stream_id = stream_id.next_id();
+        Ok(stream_id)
+    }
+
+    pub fn reserve_local(&mut self) -> Result<StreamId, UserError> {
+        let stream_id = self.ensure_next_stream_id()?;
+        self.next_stream_id = stream_id.next_id();
+        Ok(stream_id)
+    }
+
+    fn check_headers(fields: &http::HeaderMap) -> Result<(), UserError> {
+        // 8.1.2.2. Connection-Specific Header Fields
+        if fields.contains_key(http::header::CONNECTION)
+            || fields.contains_key(http::header::TRANSFER_ENCODING)
+            || fields.contains_key(http::header::UPGRADE)
+            || fields.contains_key("keep-alive")
+            || fields.contains_key("proxy-connection")
+        {
+            tracing::debug!("illegal connection-specific headers found");
+            return Err(UserError::MalformedHeaders);
+        } else if let Some(te) = fields.get(http::header::TE) {
+            if te != "trailers" {
+                tracing::debug!("illegal connection-specific headers found");
+                return Err(UserError::MalformedHeaders);
+            }
+        }
+        Ok(())
+    }
+
+    pub fn send_push_promise<B>(
+        &mut self,
+        frame: frame::PushPromise,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        task: &mut Option<Waker>,
+    ) -> Result<(), UserError> {
+        if !self.is_push_enabled {
+            return Err(UserError::PeerDisabledServerPush);
+        }
+
+        tracing::trace!(
+            "send_push_promise; frame={:?}; init_window={:?}",
+            frame,
+            self.init_window_sz
+        );
+
+        Self::check_headers(frame.fields())?;
+
+        // Queue the frame for sending
+        self.prioritize
+            .queue_frame(frame.into(), buffer, stream, task);
+
+        Ok(())
+    }
+
+    pub fn send_headers<B>(
+        &mut self,
+        frame: frame::Headers,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), UserError> {
+        tracing::trace!(
+            "send_headers; frame={:?}; init_window={:?}",
+            frame,
+            self.init_window_sz
+        );
+
+        Self::check_headers(frame.fields())?;
+
+        let end_stream = frame.is_end_stream();
+
+        // Update the state
+        stream.state.send_open(end_stream)?;
+
+        let mut pending_open = false;
+        if counts.peer().is_local_init(frame.stream_id()) && !stream.is_pending_push {
+            self.prioritize.queue_open(stream);
+            pending_open = true;
+        }
+
+        // Queue the frame for sending
+        //
+        // This call expects that, since new streams are in the open queue, new
+        // streams won't be pushed on pending_send.
+        self.prioritize
+            .queue_frame(frame.into(), buffer, stream, task);
+
+        // Need to notify the connection when pushing onto pending_open since
+        // queue_frame only notifies for pending_send.
+        if pending_open {
+            if let Some(task) = task.take() {
+                task.wake();
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Send interim informational headers (1xx responses) without changing stream state.
+    /// This allows multiple interim informational responses to be sent before the final response.
+    pub fn send_interim_informational_headers<B>(
+        &mut self,
+        frame: frame::Headers,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        _counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), UserError> {
+        tracing::trace!(
+            "send_interim_informational_headers; frame={:?}; stream_id={:?}",
+            frame,
+            frame.stream_id()
+        );
+
+        // Validate headers
+        Self::check_headers(frame.fields())?;
+
+        debug_assert!(frame.is_informational(),
+            "Frame must be informational (1xx status code) at this point. Validation should happen at the public API boundary.");
+        debug_assert!(!frame.is_end_stream(),
+            "Informational frames must not have end_stream flag set. Validation should happen at the internal send informational header streams.");
+
+        // Queue the frame for sending WITHOUT changing stream state
+        // This is the key difference from send_headers - we don't call stream.state.send_open()
+        self.prioritize
+            .queue_frame(frame.into(), buffer, stream, task);
+
+        Ok(())
+    }
+
+    /// Send an explicit RST_STREAM frame
+    pub fn send_reset<B>(
+        &mut self,
+        reason: Reason,
+        initiator: Initiator,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) {
+        let is_reset = stream.state.is_reset();
+        let is_closed = stream.state.is_closed();
+        let is_empty = stream.pending_send.is_empty();
+        let stream_id = stream.id;
+
+        tracing::trace!(
+            "send_reset(..., reason={:?}, initiator={:?}, stream={:?}, ..., \
+             is_reset={:?}; is_closed={:?}; pending_send.is_empty={:?}; \
+             state={:?} \
+             ",
+            reason,
+            initiator,
+            stream_id,
+            is_reset,
+            is_closed,
+            is_empty,
+            stream.state
+        );
+
+        if is_reset {
+            // Don't double reset
+            tracing::trace!(
+                " -> not sending RST_STREAM ({:?} is already reset)",
+                stream_id
+            );
+            return;
+        }
+
+        // Transition the state to reset no matter what.
+        stream.set_reset(reason, initiator);
+
+        // If closed AND the send queue is flushed, then the stream cannot be
+        // reset explicitly, either. Implicit resets can still be queued.
+        if is_closed && is_empty {
+            tracing::trace!(
+                " -> not sending explicit RST_STREAM ({:?} was closed \
+                 and send queue was flushed)",
+                stream_id
+            );
+            return;
+        }
+
+        // Clear all pending outbound frames.
+        // Note that we don't call `self.recv_err` because we want to enqueue
+        // the reset frame before transitioning the stream inside
+        // `reclaim_all_capacity`.
+        self.prioritize.clear_queue(buffer, stream);
+
+        let frame = frame::Reset::new(stream.id, reason);
+
+        tracing::trace!("send_reset -- queueing; frame={:?}", frame);
+        self.prioritize
+            .queue_frame(frame.into(), buffer, stream, task);
+        self.prioritize.reclaim_all_capacity(stream, counts);
+    }
+
+    pub fn schedule_implicit_reset(
+        &mut self,
+        stream: &mut store::Ptr,
+        reason: Reason,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) {
+        if stream.state.is_closed() {
+            // Stream is already closed, nothing more to do
+            return;
+        }
+
+        stream.state.set_scheduled_reset(reason);
+
+        self.prioritize.reclaim_reserved_capacity(stream, counts);
+        self.prioritize.schedule_send(stream, task);
+    }
+
+    pub fn send_data<B>(
+        &mut self,
+        frame: frame::Data<B>,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), UserError>
+    where
+        B: Buf,
+    {
+        self.prioritize
+            .send_data(frame, buffer, stream, counts, task)
+    }
+
+    pub fn send_trailers<B>(
+        &mut self,
+        frame: frame::Headers,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), UserError> {
+        // TODO: Should this logic be moved into state.rs?
+        if !stream.state.is_send_streaming() {
+            return Err(UserError::UnexpectedFrameType);
+        }
+
+        stream.state.send_close();
+
+        tracing::trace!("send_trailers -- queuing; frame={:?}", frame);
+        self.prioritize
+            .queue_frame(frame.into(), buffer, stream, task);
+
+        // Release any excess capacity
+        self.prioritize.reserve_capacity(0, stream, counts);
+
+        Ok(())
+    }
+
+    pub fn poll_complete<T, B>(
+        &mut self,
+        cx: &mut Context,
+        buffer: &mut Buffer<Frame<B>>,
+        store: &mut Store,
+        counts: &mut Counts,
+        dst: &mut Codec<T, Prioritized<B>>,
+    ) -> Poll<io::Result<()>>
+    where
+        T: AsyncWrite + Unpin,
+        B: Buf,
+    {
+        self.prioritize
+            .poll_complete(cx, buffer, store, counts, dst)
+    }
+
+    /// Request capacity to send data
+    pub fn reserve_capacity(
+        &mut self,
+        capacity: WindowSize,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+    ) {
+        self.prioritize.reserve_capacity(capacity, stream, counts)
+    }
+
+    pub fn poll_capacity(
+        &mut self,
+        cx: &Context,
+        stream: &mut store::Ptr,
+    ) -> Poll<Option<Result<WindowSize, UserError>>> {
+        if !stream.state.is_send_streaming() {
+            return Poll::Ready(None);
+        }
+
+        if !stream.send_capacity_inc {
+            stream.wait_send(cx);
+            return Poll::Pending;
+        }
+
+        stream.send_capacity_inc = false;
+
+        Poll::Ready(Some(Ok(self.capacity(stream))))
+    }
+
+    /// Current available stream send capacity
+    pub fn capacity(&self, stream: &mut store::Ptr) -> WindowSize {
+        stream.capacity(self.prioritize.max_buffer_size())
+    }
+
+    pub fn poll_reset(
+        &self,
+        cx: &Context,
+        stream: &mut Stream,
+        mode: PollReset,
+    ) -> Poll<Result<Reason, crate::Error>> {
+        match stream.state.ensure_reason(mode)? {
+            Some(reason) => Poll::Ready(Ok(reason)),
+            None => {
+                stream.wait_send(cx);
+                Poll::Pending
+            }
+        }
+    }
+
+    pub fn recv_connection_window_update(
+        &mut self,
+        frame: frame::WindowUpdate,
+        store: &mut Store,
+        counts: &mut Counts,
+    ) -> Result<(), Reason> {
+        self.prioritize
+            .recv_connection_window_update(frame.size_increment(), store, counts)
+    }
+
+    pub fn recv_stream_window_update<B>(
+        &mut self,
+        sz: WindowSize,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), Reason> {
+        if let Err(e) = self.prioritize.recv_stream_window_update(sz, stream) {
+            tracing::debug!("recv_stream_window_update !!; err={:?}", e);
+
+            self.send_reset(
+                Reason::FLOW_CONTROL_ERROR,
+                Initiator::Library,
+                buffer,
+                stream,
+                counts,
+                task,
+            );
+
+            return Err(e);
+        }
+
+        Ok(())
+    }
+
+    pub(super) fn recv_go_away(&mut self, last_stream_id: StreamId) -> Result<(), Error> {
+        if last_stream_id > self.max_stream_id {
+            // The remote endpoint sent a `GOAWAY` frame indicating a stream
+            // that we never sent, or that we have already terminated on account
+            // of previous `GOAWAY` frame. In either case, that is illegal.
+            // (When sending multiple `GOAWAY`s, "Endpoints MUST NOT increase
+            // the value they send in the last stream identifier, since the
+            // peers might already have retried unprocessed requests on another
+            // connection.")
+            proto_err!(conn:
+                "recv_go_away: last_stream_id ({:?}) > max_stream_id ({:?})",
+                last_stream_id, self.max_stream_id,
+            );
+            return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+        }
+
+        self.max_stream_id = last_stream_id;
+        Ok(())
+    }
+
+    pub fn handle_error<B>(
+        &mut self,
+        buffer: &mut Buffer<Frame<B>>,
+        stream: &mut store::Ptr,
+        counts: &mut Counts,
+    ) {
+        // Clear all pending outbound frames
+        self.prioritize.clear_queue(buffer, stream);
+        self.prioritize.reclaim_all_capacity(stream, counts);
+    }
+
+    pub fn apply_remote_settings<B>(
+        &mut self,
+        settings: &frame::Settings,
+        buffer: &mut Buffer<Frame<B>>,
+        store: &mut Store,
+        counts: &mut Counts,
+        task: &mut Option<Waker>,
+    ) -> Result<(), Error> {
+        if let Some(val) = settings.is_extended_connect_protocol_enabled() {
+            self.is_extended_connect_protocol_enabled = val;
+        }
+
+        // Applies an update to the remote endpoint's initial window size.
+        //
+        // Per RFC 7540 §6.9.2:
+        //
+        // In addition to changing the flow-control window for streams that are
+        // not yet active, a SETTINGS frame can alter the initial flow-control
+        // window size for streams with active flow-control windows (that is,
+        // streams in the "open" or "half-closed (remote)" state). When the
+        // value of SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST adjust
+        // the size of all stream flow-control windows that it maintains by the
+        // difference between the new value and the old value.
+        //
+        // A change to `SETTINGS_INITIAL_WINDOW_SIZE` can cause the available
+        // space in a flow-control window to become negative. A sender MUST
+        // track the negative flow-control window and MUST NOT send new
+        // flow-controlled frames until it receives WINDOW_UPDATE frames that
+        // cause the flow-control window to become positive.
+        if let Some(val) = settings.initial_window_size() {
+            let old_val = self.init_window_sz;
+            self.init_window_sz = val;
+
+            match val.cmp(&old_val) {
+                Ordering::Less => {
+                    // We must decrease the (remote) window on every open stream.
+                    let dec = old_val - val;
+                    tracing::trace!("decrementing all windows; dec={}", dec);
+
+                    let mut total_reclaimed = 0;
+                    store.try_for_each(|mut stream| {
+                        let stream = &mut *stream;
+
+                        if stream.state.is_send_closed() && stream.buffered_send_data == 0 {
+                            tracing::trace!(
+                                "skipping send-closed stream; id={:?}; flow={:?}",
+                                stream.id,
+                                stream.send_flow
+                            );
+
+                            return Ok(());
+                        }
+
+                        tracing::trace!(
+                            "decrementing stream window; id={:?}; decr={}; flow={:?}",
+                            stream.id,
+                            dec,
+                            stream.send_flow
+                        );
+
+                        // TODO: this decrement can underflow based on received frames!
+                        stream
+                            .send_flow
+                            .dec_send_window(dec)
+                            .map_err(proto::Error::library_go_away)?;
+
+                        // It's possible that decreasing the window causes
+                        // `window_size` (the stream-specific window) to fall below
+                        // `available` (the portion of the connection-level window
+                        // that we have allocated to the stream).
+                        // In this case, we should take that excess allocation away
+                        // and reassign it to other streams.
+                        let window_size = stream.send_flow.window_size();
+                        let available = stream.send_flow.available().as_size();
+                        let reclaimed = if available > window_size {
+                            // Drop down to `window_size`.
+                            let reclaim = available - window_size;
+                            stream
+                                .send_flow
+                                .claim_capacity(reclaim)
+                                .map_err(proto::Error::library_go_away)?;
+                            total_reclaimed += reclaim;
+                            reclaim
+                        } else {
+                            0
+                        };
+
+                        tracing::trace!(
+                            "decremented stream window; id={:?}; decr={}; reclaimed={}; flow={:?}",
+                            stream.id,
+                            dec,
+                            reclaimed,
+                            stream.send_flow
+                        );
+
+                        // TODO: Should this notify the producer when the capacity
+                        // of a stream is reduced? Maybe it should if the capacity
+                        // is reduced to zero, allowing the producer to stop work.
+
+                        Ok::<_, proto::Error>(())
+                    })?;
+
+                    self.prioritize
+                        .assign_connection_capacity(total_reclaimed, store, counts);
+                }
+                Ordering::Greater => {
+                    let inc = val - old_val;
+
+                    store.try_for_each(|mut stream| {
+                        self.recv_stream_window_update(inc, buffer, &mut stream, counts, task)
+                            .map_err(Error::library_go_away)
+                    })?;
+                }
+                Ordering::Equal => (),
+            }
+        }
+
+        if let Some(val) = settings.is_push_enabled() {
+            self.is_push_enabled = val
+        }
+
+        Ok(())
+    }
+
+    pub fn clear_queues(&mut self, store: &mut Store, counts: &mut Counts) {
+        self.prioritize.clear_pending_capacity(store, counts);
+        self.prioritize.clear_pending_send(store, counts);
+        self.prioritize.clear_pending_open(store, counts);
+    }
+
+    pub fn ensure_not_idle(&self, id: StreamId) -> Result<(), Reason> {
+        if let Ok(next) = self.next_stream_id {
+            if id >= next {
+                return Err(Reason::PROTOCOL_ERROR);
+            }
+        }
+        // if next_stream_id is overflowed, that's ok.
+
+        Ok(())
+    }
+
+    pub fn ensure_next_stream_id(&self) -> Result<StreamId, UserError> {
+        self.next_stream_id
+            .map_err(|_| UserError::OverflowedStreamId)
+    }
+
+    pub fn may_have_created_stream(&self, id: StreamId) -> bool {
+        if let Ok(next_id) = self.next_stream_id {
+            // Peer::is_local_init should have been called beforehand
+            debug_assert_eq!(id.is_server_initiated(), next_id.is_server_initiated(),);
+            id < next_id
+        } else {
+            true
+        }
+    }
+
+    pub(super) fn maybe_reset_next_stream_id(&mut self, id: StreamId) {
+        if let Ok(next_id) = self.next_stream_id {
+            // Peer::is_local_init should have been called beforehand
+            debug_assert_eq!(id.is_server_initiated(), next_id.is_server_initiated());
+            if id >= next_id {
+                self.next_stream_id = id.next_id();
+            }
+        }
+    }
+
+    pub(crate) fn is_extended_connect_protocol_enabled(&self) -> bool {
+        self.is_extended_connect_protocol_enabled
+    }
+}

vendor/h2/src/proto/streams/state.rs

@@ -0,0 +1,475 @@
+use std::fmt;
+use std::io;
+
+use crate::codec::UserError;
+use crate::frame::{self, Reason, StreamId};
+use crate::proto::{self, Error, Initiator, PollReset};
+
+use self::Inner::*;
+use self::Peer::*;
+
+/// Represents the state of an H2 stream
+///
+/// ```not_rust
+///                              +--------+
+///                      send PP |        | recv PP
+///                     ,--------|  idle  |--------.
+///                    /         |        |         \
+///                   v          +--------+          v
+///            +----------+          |           +----------+
+///            |          |          | send H /  |          |
+///     ,------| reserved |          | recv H    | reserved |------.
+///     |      | (local)  |          |           | (remote) |      |
+///     |      +----------+          v           +----------+      |
+///     |          |             +--------+             |          |
+///     |          |     recv ES |        | send ES     |          |
+///     |   send H |     ,-------|  open  |-------.     | recv H   |
+///     |          |    /        |        |        \    |          |
+///     |          v   v         +--------+         v   v          |
+///     |      +----------+          |           +----------+      |
+///     |      |   half   |          |           |   half   |      |
+///     |      |  closed  |          | send R /  |  closed  |      |
+///     |      | (remote) |          | recv R    | (local)  |      |
+///     |      +----------+          |           +----------+      |
+///     |           |                |                 |           |
+///     |           | send ES /      |       recv ES / |           |
+///     |           | send R /       v        send R / |           |
+///     |           | recv R     +--------+   recv R   |           |
+///     | send R /  `----------->|        |<-----------'  send R / |
+///     | recv R                 | closed |               recv R   |
+///     `----------------------->|        |<----------------------'
+///                              +--------+
+///
+///        send:   endpoint sends this frame
+///        recv:   endpoint receives this frame
+///
+///        H:  HEADERS frame (with implied CONTINUATIONs)
+///        PP: PUSH_PROMISE frame (with implied CONTINUATIONs)
+///        ES: END_STREAM flag
+///        R:  RST_STREAM frame
+/// ```
+#[derive(Clone)]
+pub struct State {
+    inner: Inner,
+}
+
+#[derive(Debug, Clone)]
+enum Inner {
+    Idle,
+    // TODO: these states shouldn't count against concurrency limits:
+    ReservedLocal,
+    ReservedRemote,
+    Open { local: Peer, remote: Peer },
+    HalfClosedLocal(Peer), // TODO: explicitly name this value
+    HalfClosedRemote(Peer),
+    Closed(Cause),
+}
+
+#[derive(Debug, Copy, Clone, Default)]
+enum Peer {
+    #[default]
+    AwaitingHeaders,
+    Streaming,
+}
+
+#[derive(Debug, Clone)]
+enum Cause {
+    EndStream,
+    Error(Error),
+
+    /// This indicates to the connection that a reset frame must be sent out
+    /// once the send queue has been flushed.
+    ///
+    /// Examples of when this could happen:
+    /// - User drops all references to a stream, so we want to CANCEL the it.
+    /// - Header block size was too large, so we want to REFUSE, possibly
+    ///   after sending a 431 response frame.
+    ScheduledLibraryReset(Reason),
+}
+
+impl State {
+    /// Opens the send-half of a stream if it is not already open.
+    pub fn send_open(&mut self, eos: bool) -> Result<(), UserError> {
+        let local = Streaming;
+
+        self.inner = match self.inner {
+            Idle => {
+                if eos {
+                    HalfClosedLocal(AwaitingHeaders)
+                } else {
+                    Open {
+                        local,
+                        remote: AwaitingHeaders,
+                    }
+                }
+            }
+            Open {
+                local: AwaitingHeaders,
+                remote,
+            } => {
+                if eos {
+                    HalfClosedLocal(remote)
+                } else {
+                    Open { local, remote }
+                }
+            }
+            HalfClosedRemote(AwaitingHeaders) | ReservedLocal => {
+                if eos {
+                    Closed(Cause::EndStream)
+                } else {
+                    HalfClosedRemote(local)
+                }
+            }
+            _ => {
+                // All other transitions result in a protocol error
+                return Err(UserError::UnexpectedFrameType);
+            }
+        };
+
+        Ok(())
+    }
+
+    /// Opens the receive-half of the stream when a HEADERS frame is received.
+    ///
+    /// Returns true if this transitions the state to Open.
+    pub fn recv_open(&mut self, frame: &frame::Headers) -> Result<bool, Error> {
+        let mut initial = false;
+        let eos = frame.is_end_stream();
+
+        self.inner = match self.inner {
+            Idle => {
+                initial = true;
+
+                if eos {
+                    HalfClosedRemote(AwaitingHeaders)
+                } else {
+                    Open {
+                        local: AwaitingHeaders,
+                        remote: if frame.is_informational() {
+                            tracing::trace!("skipping 1xx response headers");
+                            AwaitingHeaders
+                        } else {
+                            Streaming
+                        },
+                    }
+                }
+            }
+            ReservedRemote => {
+                initial = true;
+
+                if eos {
+                    Closed(Cause::EndStream)
+                } else if frame.is_informational() {
+                    tracing::trace!("skipping 1xx response headers");
+                    ReservedRemote
+                } else {
+                    HalfClosedLocal(Streaming)
+                }
+            }
+            Open {
+                local,
+                remote: AwaitingHeaders,
+            } => {
+                if eos {
+                    HalfClosedRemote(local)
+                } else {
+                    Open {
+                        local,
+                        remote: if frame.is_informational() {
+                            tracing::trace!("skipping 1xx response headers");
+                            AwaitingHeaders
+                        } else {
+                            Streaming
+                        },
+                    }
+                }
+            }
+            HalfClosedLocal(AwaitingHeaders) => {
+                if eos {
+                    Closed(Cause::EndStream)
+                } else if frame.is_informational() {
+                    tracing::trace!("skipping 1xx response headers");
+                    HalfClosedLocal(AwaitingHeaders)
+                } else {
+                    HalfClosedLocal(Streaming)
+                }
+            }
+            ref state => {
+                // All other transitions result in a protocol error
+                proto_err!(conn: "recv_open: in unexpected state {:?}", state);
+                return Err(Error::library_go_away(Reason::PROTOCOL_ERROR));
+            }
+        };
+
+        Ok(initial)
+    }
+
+    /// Transition from Idle -> ReservedRemote
+    pub fn reserve_remote(&mut self) -> Result<(), Error> {
+        match self.inner {
+            Idle => {
+                self.inner = ReservedRemote;
+                Ok(())
+            }
+            ref state => {
+                proto_err!(conn: "reserve_remote: in unexpected state {:?}", state);
+                Err(Error::library_go_away(Reason::PROTOCOL_ERROR))
+            }
+        }
+    }
+
+    /// Transition from Idle -> ReservedLocal
+    pub fn reserve_local(&mut self) -> Result<(), UserError> {
+        match self.inner {
+            Idle => {
+                self.inner = ReservedLocal;
+                Ok(())
+            }
+            _ => Err(UserError::UnexpectedFrameType),
+        }
+    }
+
+    /// Indicates that the remote side will not send more data to the local.
+    pub fn recv_close(&mut self) -> Result<(), Error> {
+        match self.inner {
+            Open { local, .. } => {
+                // The remote side will continue to receive data.
+                tracing::trace!("recv_close: Open => HalfClosedRemote({:?})", local);
+                self.inner = HalfClosedRemote(local);
+                Ok(())
+            }
+            HalfClosedLocal(..) => {
+                tracing::trace!("recv_close: HalfClosedLocal => Closed");
+                self.inner = Closed(Cause::EndStream);
+                Ok(())
+            }
+            ref state => {
+                proto_err!(conn: "recv_close: in unexpected state {:?}", state);
+                Err(Error::library_go_away(Reason::PROTOCOL_ERROR))
+            }
+        }
+    }
+
+    /// The remote explicitly sent a RST_STREAM.
+    ///
+    /// # Arguments
+    /// - `frame`: the received RST_STREAM frame.
+    /// - `queued`: true if this stream has frames in the pending send queue.
+    pub fn recv_reset(&mut self, frame: frame::Reset, queued: bool) {
+        match self.inner {
+            // If the stream is already in a `Closed` state, do nothing,
+            // provided that there are no frames still in the send queue.
+            Closed(..) if !queued => {}
+            // A notionally `Closed` stream may still have queued frames in
+            // the following cases:
+            //
+            // - if the cause is `Cause::Scheduled(..)` (i.e. we have not
+            //   actually closed the stream yet).
+            // - if the cause is `Cause::EndStream`: we transition to this
+            //   state when an EOS frame is *enqueued* (so that it's invalid
+            //   to enqueue more frames), not when the EOS frame is *sent*;
+            //   therefore, there may still be frames ahead of the EOS frame
+            //   in the send queue.
+            //
+            // In either of these cases, we want to overwrite the stream's
+            // previous state with the received RST_STREAM, so that the queue
+            // will be cleared by `Prioritize::pop_frame`.
+            ref state => {
+                tracing::trace!(
+                    "recv_reset; frame={:?}; state={:?}; queued={:?}",
+                    frame,
+                    state,
+                    queued
+                );
+                self.inner = Closed(Cause::Error(Error::remote_reset(
+                    frame.stream_id(),
+                    frame.reason(),
+                )));
+            }
+        }
+    }
+
+    /// Handle a connection-level error.
+    pub fn handle_error(&mut self, err: &proto::Error) {
+        match self.inner {
+            Closed(..) => {}
+            _ => {
+                tracing::trace!("handle_error; err={:?}", err);
+                self.inner = Closed(Cause::Error(err.clone()));
+            }
+        }
+    }
+
+    pub fn recv_eof(&mut self) {
+        match self.inner {
+            Closed(..) => {}
+            ref state => {
+                tracing::trace!("recv_eof; state={:?}", state);
+                self.inner = Closed(Cause::Error(
+                    io::Error::new(
+                        io::ErrorKind::BrokenPipe,
+                        "stream closed because of a broken pipe",
+                    )
+                    .into(),
+                ));
+            }
+        }
+    }
+
+    /// Indicates that the local side will not send more data to the local.
+    pub fn send_close(&mut self) {
+        match self.inner {
+            Open { remote, .. } => {
+                // The remote side will continue to receive data.
+                tracing::trace!("send_close: Open => HalfClosedLocal({:?})", remote);
+                self.inner = HalfClosedLocal(remote);
+            }
+            HalfClosedRemote(..) => {
+                tracing::trace!("send_close: HalfClosedRemote => Closed");
+                self.inner = Closed(Cause::EndStream);
+            }
+            ref state => panic!("send_close: unexpected state {:?}", state),
+        }
+    }
+
+    /// Set the stream state to reset locally.
+    pub fn set_reset(&mut self, stream_id: StreamId, reason: Reason, initiator: Initiator) {
+        self.inner = Closed(Cause::Error(Error::Reset(stream_id, reason, initiator)));
+    }
+
+    /// Set the stream state to a scheduled reset.
+    pub fn set_scheduled_reset(&mut self, reason: Reason) {
+        debug_assert!(!self.is_closed());
+        self.inner = Closed(Cause::ScheduledLibraryReset(reason));
+    }
+
+    pub fn get_scheduled_reset(&self) -> Option<Reason> {
+        match self.inner {
+            Closed(Cause::ScheduledLibraryReset(reason)) => Some(reason),
+            _ => None,
+        }
+    }
+
+    pub fn is_scheduled_reset(&self) -> bool {
+        matches!(self.inner, Closed(Cause::ScheduledLibraryReset(..)))
+    }
+
+    pub fn is_local_error(&self) -> bool {
+        match self.inner {
+            Closed(Cause::Error(ref e)) => e.is_local(),
+            Closed(Cause::ScheduledLibraryReset(..)) => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_remote_reset(&self) -> bool {
+        matches!(
+            self.inner,
+            Closed(Cause::Error(Error::Reset(_, _, Initiator::Remote)))
+        )
+    }
+
+    /// Returns true if the stream is already reset.
+    pub fn is_reset(&self) -> bool {
+        match self.inner {
+            Closed(Cause::EndStream) => false,
+            Closed(_) => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_send_streaming(&self) -> bool {
+        matches!(
+            self.inner,
+            Open {
+                local: Streaming,
+                ..
+            } | HalfClosedRemote(Streaming)
+        )
+    }
+
+    /// Returns true when the stream is in a state to receive headers
+    pub fn is_recv_headers(&self) -> bool {
+        matches!(
+            self.inner,
+            Idle | Open {
+                remote: AwaitingHeaders,
+                ..
+            } | HalfClosedLocal(AwaitingHeaders)
+                | ReservedRemote
+        )
+    }
+
+    pub fn is_recv_streaming(&self) -> bool {
+        matches!(
+            self.inner,
+            Open {
+                remote: Streaming,
+                ..
+            } | HalfClosedLocal(Streaming)
+        )
+    }
+
+    pub fn is_recv_end_stream(&self) -> bool {
+        // In either case END_STREAM has been received
+        matches!(self.inner, Closed(Cause::EndStream) | HalfClosedRemote(..))
+    }
+
+    pub fn is_closed(&self) -> bool {
+        matches!(self.inner, Closed(_))
+    }
+
+    pub fn is_send_closed(&self) -> bool {
+        matches!(
+            self.inner,
+            Closed(..) | HalfClosedLocal(..) | ReservedRemote
+        )
+    }
+
+    pub fn is_idle(&self) -> bool {
+        matches!(self.inner, Idle)
+    }
+
+    pub fn ensure_recv_open(&self) -> Result<bool, proto::Error> {
+        // TODO: Is this correct?
+        match self.inner {
+            Closed(Cause::Error(ref e)) => Err(e.clone()),
+            Closed(Cause::ScheduledLibraryReset(reason)) => {
+                Err(proto::Error::library_go_away(reason))
+            }
+            Closed(Cause::EndStream) | HalfClosedRemote(..) | ReservedLocal => Ok(false),
+            _ => Ok(true),
+        }
+    }
+
+    /// Returns a reason if the stream has been reset.
+    pub(super) fn ensure_reason(&self, mode: PollReset) -> Result<Option<Reason>, crate::Error> {
+        match self.inner {
+            Closed(Cause::Error(Error::Reset(_, reason, _)))
+            | Closed(Cause::Error(Error::GoAway(_, reason, _)))
+            | Closed(Cause::ScheduledLibraryReset(reason)) => Ok(Some(reason)),
+            Closed(Cause::Error(ref e)) => Err(e.clone().into()),
+            Open {
+                local: Streaming, ..
+            }
+            | HalfClosedRemote(Streaming) => match mode {
+                PollReset::AwaitingHeaders => Err(UserError::PollResetAfterSendResponse.into()),
+                PollReset::Streaming => Ok(None),
+            },
+            _ => Ok(None),
+        }
+    }
+}
+
+impl Default for State {
+    fn default() -> State {
+        State { inner: Inner::Idle }
+    }
+}
+
+// remove some noise for debug output
+impl fmt::Debug for State {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.inner.fmt(f)
+    }
+}

vendor/h2/src/proto/streams/store.rs

@@ -0,0 +1,474 @@
+use super::*;
+
+use indexmap::{self, IndexMap};
+
+use std::convert::Infallible;
+use std::fmt;
+use std::marker::PhantomData;
+use std::ops;
+
+/// Storage for streams
+#[derive(Debug)]
+pub(super) struct Store {
+    slab: slab::Slab<Stream>,
+    ids: IndexMap<StreamId, SlabIndex>,
+}
+
+/// "Pointer" to an entry in the store
+pub(super) struct Ptr<'a> {
+    key: Key,
+    store: &'a mut Store,
+}
+
+/// References an entry in the store.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) struct Key {
+    index: SlabIndex,
+    /// Keep the stream ID in the key as an ABA guard, since slab indices
+    /// could be re-used with a new stream.
+    stream_id: StreamId,
+}
+
+// We can never have more than `StreamId::MAX` streams in the store,
+// so we can save a smaller index (u32 vs usize).
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+struct SlabIndex(u32);
+
+pub(super) struct Queue<N> {
+    indices: Option<store::Indices>,
+    _p: PhantomData<N>,
+}
+
+pub(super) trait Next {
+    fn next(stream: &Stream) -> Option<Key>;
+
+    fn set_next(stream: &mut Stream, key: Option<Key>);
+
+    fn take_next(stream: &mut Stream) -> Option<Key>;
+
+    fn is_queued(stream: &Stream) -> bool;
+
+    fn set_queued(stream: &mut Stream, val: bool);
+}
+
+/// A linked list
+#[derive(Debug, Clone, Copy)]
+struct Indices {
+    pub head: Key,
+    pub tail: Key,
+}
+
+pub(super) enum Entry<'a> {
+    Occupied(OccupiedEntry<'a>),
+    Vacant(VacantEntry<'a>),
+}
+
+pub(super) struct OccupiedEntry<'a> {
+    ids: indexmap::map::OccupiedEntry<'a, StreamId, SlabIndex>,
+}
+
+pub(super) struct VacantEntry<'a> {
+    ids: indexmap::map::VacantEntry<'a, StreamId, SlabIndex>,
+    slab: &'a mut slab::Slab<Stream>,
+}
+
+pub(super) trait Resolve {
+    fn resolve(&mut self, key: Key) -> Ptr<'_>;
+}
+
+// ===== impl Store =====
+
+impl Store {
+    pub fn new() -> Self {
+        Store {
+            slab: slab::Slab::new(),
+            ids: IndexMap::new(),
+        }
+    }
+
+    pub fn find_mut(&mut self, id: &StreamId) -> Option<Ptr<'_>> {
+        let index = match self.ids.get(id) {
+            Some(key) => *key,
+            None => return None,
+        };
+
+        Some(Ptr {
+            key: Key {
+                index,
+                stream_id: *id,
+            },
+            store: self,
+        })
+    }
+
+    pub fn insert(&mut self, id: StreamId, val: Stream) -> Ptr<'_> {
+        let index = SlabIndex(self.slab.insert(val) as u32);
+        assert!(self.ids.insert(id, index).is_none());
+
+        Ptr {
+            key: Key {
+                index,
+                stream_id: id,
+            },
+            store: self,
+        }
+    }
+
+    pub fn find_entry(&mut self, id: StreamId) -> Entry<'_> {
+        use self::indexmap::map::Entry::*;
+
+        match self.ids.entry(id) {
+            Occupied(e) => Entry::Occupied(OccupiedEntry { ids: e }),
+            Vacant(e) => Entry::Vacant(VacantEntry {
+                ids: e,
+                slab: &mut self.slab,
+            }),
+        }
+    }
+
+    #[allow(clippy::blocks_in_conditions)]
+    pub(crate) fn for_each<F>(&mut self, mut f: F)
+    where
+        F: FnMut(Ptr),
+    {
+        match self.try_for_each(|ptr| {
+            f(ptr);
+            Ok::<_, Infallible>(())
+        }) {
+            Ok(()) => (),
+            #[allow(unused)]
+            Err(infallible) => match infallible {},
+        }
+    }
+
+    pub fn try_for_each<F, E>(&mut self, mut f: F) -> Result<(), E>
+    where
+        F: FnMut(Ptr) -> Result<(), E>,
+    {
+        let mut len = self.ids.len();
+        let mut i = 0;
+
+        while i < len {
+            // Get the key by index, this makes the borrow checker happy
+            let (stream_id, index) = {
+                let entry = self.ids.get_index(i).unwrap();
+                (*entry.0, *entry.1)
+            };
+
+            f(Ptr {
+                key: Key { index, stream_id },
+                store: self,
+            })?;
+
+            // TODO: This logic probably could be better...
+            let new_len = self.ids.len();
+
+            if new_len < len {
+                debug_assert!(new_len == len - 1);
+                len -= 1;
+            } else {
+                i += 1;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl Resolve for Store {
+    fn resolve(&mut self, key: Key) -> Ptr<'_> {
+        Ptr { key, store: self }
+    }
+}
+
+impl ops::Index<Key> for Store {
+    type Output = Stream;
+
+    fn index(&self, key: Key) -> &Self::Output {
+        self.slab
+            .get(key.index.0 as usize)
+            .filter(|s| s.id == key.stream_id)
+            .unwrap_or_else(|| {
+                panic!("dangling store key for stream_id={:?}", key.stream_id);
+            })
+    }
+}
+
+impl ops::IndexMut<Key> for Store {
+    fn index_mut(&mut self, key: Key) -> &mut Self::Output {
+        self.slab
+            .get_mut(key.index.0 as usize)
+            .filter(|s| s.id == key.stream_id)
+            .unwrap_or_else(|| {
+                panic!("dangling store key for stream_id={:?}", key.stream_id);
+            })
+    }
+}
+
+impl Store {
+    #[cfg(feature = "unstable")]
+    pub fn num_active_streams(&self) -> usize {
+        self.ids.len()
+    }
+
+    #[cfg(feature = "unstable")]
+    pub fn num_wired_streams(&self) -> usize {
+        self.slab.len()
+    }
+}
+
+// While running h2 unit/integration tests, enable this debug assertion.
+//
+// In practice, we don't need to ensure this. But the integration tests
+// help to make sure we've cleaned up in cases where we could (like, the
+// runtime isn't suddenly dropping the task for unknown reasons).
+#[cfg(feature = "unstable")]
+impl Drop for Store {
+    fn drop(&mut self) {
+        use std::thread;
+
+        if !thread::panicking() {
+            debug_assert!(self.slab.is_empty());
+        }
+    }
+}
+
+// ===== impl Queue =====
+
+impl<N> Queue<N>
+where
+    N: Next,
+{
+    pub fn new() -> Self {
+        Queue {
+            indices: None,
+            _p: PhantomData,
+        }
+    }
+
+    pub fn take(&mut self) -> Self {
+        Queue {
+            indices: self.indices.take(),
+            _p: PhantomData,
+        }
+    }
+
+    /// Queue the stream.
+    ///
+    /// If the stream is already contained by the list, return `false`.
+    pub fn push(&mut self, stream: &mut store::Ptr) -> bool {
+        tracing::trace!("Queue::push_back");
+
+        if N::is_queued(stream) {
+            tracing::trace!(" -> already queued");
+            return false;
+        }
+
+        N::set_queued(stream, true);
+
+        // The next pointer shouldn't be set
+        debug_assert!(N::next(stream).is_none());
+
+        // Queue the stream
+        match self.indices {
+            Some(ref mut idxs) => {
+                tracing::trace!(" -> existing entries");
+
+                // Update the current tail node to point to `stream`
+                let key = stream.key();
+                N::set_next(&mut stream.resolve(idxs.tail), Some(key));
+
+                // Update the tail pointer
+                idxs.tail = stream.key();
+            }
+            None => {
+                tracing::trace!(" -> first entry");
+                self.indices = Some(store::Indices {
+                    head: stream.key(),
+                    tail: stream.key(),
+                });
+            }
+        }
+
+        true
+    }
+
+    /// Queue the stream
+    ///
+    /// If the stream is already contained by the list, return `false`.
+    pub fn push_front(&mut self, stream: &mut store::Ptr) -> bool {
+        tracing::trace!("Queue::push_front");
+
+        if N::is_queued(stream) {
+            tracing::trace!(" -> already queued");
+            return false;
+        }
+
+        N::set_queued(stream, true);
+
+        // The next pointer shouldn't be set
+        debug_assert!(N::next(stream).is_none());
+
+        // Queue the stream
+        match self.indices {
+            Some(ref mut idxs) => {
+                tracing::trace!(" -> existing entries");
+
+                // Update the provided stream to point to the head node
+                let head_key = stream.resolve(idxs.head).key();
+                N::set_next(stream, Some(head_key));
+
+                // Update the head pointer
+                idxs.head = stream.key();
+            }
+            None => {
+                tracing::trace!(" -> first entry");
+                self.indices = Some(store::Indices {
+                    head: stream.key(),
+                    tail: stream.key(),
+                });
+            }
+        }
+
+        true
+    }
+
+    pub fn pop<'a, R>(&mut self, store: &'a mut R) -> Option<store::Ptr<'a>>
+    where
+        R: Resolve,
+    {
+        if let Some(mut idxs) = self.indices {
+            let mut stream = store.resolve(idxs.head);
+
+            if idxs.head == idxs.tail {
+                assert!(N::next(&stream).is_none());
+                self.indices = None;
+            } else {
+                idxs.head = N::take_next(&mut stream).unwrap();
+                self.indices = Some(idxs);
+            }
+
+            debug_assert!(N::is_queued(&stream));
+            N::set_queued(&mut stream, false);
+
+            return Some(stream);
+        }
+
+        None
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.indices.is_none()
+    }
+
+    pub fn pop_if<'a, R, F>(&mut self, store: &'a mut R, f: F) -> Option<store::Ptr<'a>>
+    where
+        R: Resolve,
+        F: Fn(&Stream) -> bool,
+    {
+        if let Some(idxs) = self.indices {
+            let should_pop = f(&store.resolve(idxs.head));
+            if should_pop {
+                return self.pop(store);
+            }
+        }
+
+        None
+    }
+}
+
+impl<N> fmt::Debug for Queue<N> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("Queue")
+            .field("indices", &self.indices)
+            // skip phantom data
+            .finish()
+    }
+}
+
+// ===== impl Ptr =====
+
+impl<'a> Ptr<'a> {
+    /// Returns the Key associated with the stream
+    pub fn key(&self) -> Key {
+        self.key
+    }
+
+    pub fn store_mut(&mut self) -> &mut Store {
+        self.store
+    }
+
+    /// Remove the stream from the store
+    pub fn remove(self) -> StreamId {
+        // The stream must have been unlinked before this point
+        debug_assert!(!self.store.ids.contains_key(&self.key.stream_id));
+
+        // Remove the stream state
+        let stream = self.store.slab.remove(self.key.index.0 as usize);
+        assert_eq!(stream.id, self.key.stream_id);
+        stream.id
+    }
+
+    /// Remove the StreamId -> stream state association.
+    ///
+    /// This will effectively remove the stream as far as the H2 protocol is
+    /// concerned.
+    pub fn unlink(&mut self) {
+        let id = self.key.stream_id;
+        self.store.ids.swap_remove(&id);
+    }
+}
+
+impl<'a> Resolve for Ptr<'a> {
+    fn resolve(&mut self, key: Key) -> Ptr<'_> {
+        Ptr {
+            key,
+            store: &mut *self.store,
+        }
+    }
+}
+
+impl<'a> ops::Deref for Ptr<'a> {
+    type Target = Stream;
+
+    fn deref(&self) -> &Stream {
+        &self.store[self.key]
+    }
+}
+
+impl<'a> ops::DerefMut for Ptr<'a> {
+    fn deref_mut(&mut self) -> &mut Stream {
+        &mut self.store[self.key]
+    }
+}
+
+impl<'a> fmt::Debug for Ptr<'a> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        (**self).fmt(fmt)
+    }
+}
+
+// ===== impl OccupiedEntry =====
+
+impl<'a> OccupiedEntry<'a> {
+    pub fn key(&self) -> Key {
+        let stream_id = *self.ids.key();
+        let index = *self.ids.get();
+        Key { index, stream_id }
+    }
+}
+
+// ===== impl VacantEntry =====
+
+impl<'a> VacantEntry<'a> {
+    pub fn insert(self, value: Stream) -> Key {
+        // Insert the value in the slab
+        let stream_id = value.id;
+        let index = SlabIndex(self.slab.insert(value) as u32);
+
+        // Insert the handle in the ID map
+        self.ids.insert(index);
+
+        Key { index, stream_id }
+    }
+}

vendor/h2/src/proto/streams/stream.rs

@@ -0,0 +1,599 @@
+use crate::Reason;
+
+use super::*;
+
+use std::fmt;
+use std::task::{Context, Waker};
+use std::time::Instant;
+
+/// Tracks Stream related state
+///
+/// # Reference counting
+///
+/// There can be a number of outstanding handles to a single Stream. These are
+/// tracked using reference counting. The `ref_count` field represents the
+/// number of outstanding userspace handles that can reach this stream.
+///
+/// It's important to note that when the stream is placed in an internal queue
+/// (such as an accept queue), this is **not** tracked by a reference count.
+/// Thus, `ref_count` can be zero and the stream still has to be kept around.
+pub(super) struct Stream {
+    /// The h2 stream identifier
+    pub id: StreamId,
+
+    /// Current state of the stream
+    pub state: State,
+
+    /// Set to `true` when the stream is counted against the connection's max
+    /// concurrent streams.
+    pub is_counted: bool,
+
+    /// Number of outstanding handles pointing to this stream
+    pub ref_count: usize,
+
+    // ===== Fields related to sending =====
+    /// Next node in the accept linked list
+    pub next_pending_send: Option<store::Key>,
+
+    /// Set to true when the stream is pending accept
+    pub is_pending_send: bool,
+
+    /// Send data flow control
+    pub send_flow: FlowControl,
+
+    /// Amount of send capacity that has been requested, but not yet allocated.
+    pub requested_send_capacity: WindowSize,
+
+    /// Amount of data buffered at the prioritization layer.
+    /// TODO: Technically this could be greater than the window size...
+    pub buffered_send_data: usize,
+
+    /// Task tracking additional send capacity (i.e. window updates).
+    send_task: Option<Waker>,
+
+    /// Frames pending for this stream being sent to the socket
+    pub pending_send: buffer::Deque,
+
+    /// Next node in the linked list of streams waiting for additional
+    /// connection level capacity.
+    pub next_pending_send_capacity: Option<store::Key>,
+
+    /// True if the stream is waiting for outbound connection capacity
+    pub is_pending_send_capacity: bool,
+
+    /// Set to true when the send capacity has been incremented
+    pub send_capacity_inc: bool,
+
+    /// Next node in the open linked list
+    pub next_open: Option<store::Key>,
+
+    /// Set to true when the stream is pending to be opened
+    pub is_pending_open: bool,
+
+    /// Set to true when a push is pending for this stream
+    pub is_pending_push: bool,
+
+    // ===== Fields related to receiving =====
+    /// Next node in the accept linked list
+    pub next_pending_accept: Option<store::Key>,
+
+    /// Set to true when the stream is pending accept
+    pub is_pending_accept: bool,
+
+    /// Receive data flow control
+    pub recv_flow: FlowControl,
+
+    pub in_flight_recv_data: WindowSize,
+
+    /// Next node in the linked list of streams waiting to send window updates.
+    pub next_window_update: Option<store::Key>,
+
+    /// True if the stream is waiting to send a window update
+    pub is_pending_window_update: bool,
+
+    /// The time when this stream may have been locally reset.
+    pub reset_at: Option<Instant>,
+
+    /// Next node in list of reset streams that should expire eventually
+    pub next_reset_expire: Option<store::Key>,
+
+    /// Frames pending for this stream to read
+    pub pending_recv: buffer::Deque,
+
+    /// When the RecvStream drop occurs, no data should be received.
+    pub is_recv: bool,
+
+    /// Task tracking receiving frames
+    pub recv_task: Option<Waker>,
+
+    /// Task tracking pushed promises.
+    pub push_task: Option<Waker>,
+
+    /// The stream's pending push promises
+    pub pending_push_promises: store::Queue<NextAccept>,
+
+    /// Validate content-length headers
+    pub content_length: ContentLength,
+}
+
+/// State related to validating a stream's content-length
+#[derive(Debug)]
+pub enum ContentLength {
+    Omitted,
+    Head,
+    Remaining(u64),
+}
+
+#[derive(Debug)]
+pub(super) struct NextAccept;
+
+#[derive(Debug)]
+pub(super) struct NextSend;
+
+#[derive(Debug)]
+pub(super) struct NextSendCapacity;
+
+#[derive(Debug)]
+pub(super) struct NextWindowUpdate;
+
+#[derive(Debug)]
+pub(super) struct NextOpen;
+
+#[derive(Debug)]
+pub(super) struct NextResetExpire;
+
+impl Stream {
+    pub fn new(id: StreamId, init_send_window: WindowSize, init_recv_window: WindowSize) -> Stream {
+        let mut send_flow = FlowControl::new();
+        let mut recv_flow = FlowControl::new();
+
+        recv_flow
+            .inc_window(init_recv_window)
+            .expect("invalid initial receive window");
+        // TODO: proper error handling?
+        let _res = recv_flow.assign_capacity(init_recv_window);
+        debug_assert!(_res.is_ok());
+
+        send_flow
+            .inc_window(init_send_window)
+            .expect("invalid initial send window size");
+
+        Stream {
+            id,
+            state: State::default(),
+            ref_count: 0,
+            is_counted: false,
+
+            // ===== Fields related to sending =====
+            next_pending_send: None,
+            is_pending_send: false,
+            send_flow,
+            requested_send_capacity: 0,
+            buffered_send_data: 0,
+            send_task: None,
+            pending_send: buffer::Deque::new(),
+            is_pending_send_capacity: false,
+            next_pending_send_capacity: None,
+            send_capacity_inc: false,
+            is_pending_open: false,
+            next_open: None,
+            is_pending_push: false,
+
+            // ===== Fields related to receiving =====
+            next_pending_accept: None,
+            is_pending_accept: false,
+            recv_flow,
+            in_flight_recv_data: 0,
+            next_window_update: None,
+            is_pending_window_update: false,
+            reset_at: None,
+            next_reset_expire: None,
+            pending_recv: buffer::Deque::new(),
+            is_recv: true,
+            recv_task: None,
+            push_task: None,
+            pending_push_promises: store::Queue::new(),
+            content_length: ContentLength::Omitted,
+        }
+    }
+
+    /// Increment the stream's ref count
+    pub fn ref_inc(&mut self) {
+        assert!(self.ref_count < usize::MAX);
+        self.ref_count += 1;
+    }
+
+    /// Decrements the stream's ref count
+    pub fn ref_dec(&mut self) {
+        assert!(self.ref_count > 0);
+        self.ref_count -= 1;
+    }
+
+    /// Returns true if stream is currently being held for some time because of
+    /// a local reset.
+    pub fn is_pending_reset_expiration(&self) -> bool {
+        self.reset_at.is_some()
+    }
+
+    /// Returns true if frames for this stream are ready to be sent over the wire
+    pub fn is_send_ready(&self) -> bool {
+        // Why do we check pending_open?
+        //
+        // We allow users to call send_request() which schedules a stream to be pending_open
+        // if there is no room according to the concurrency limit (max_send_streams), and we
+        // also allow data to be buffered for send with send_data() if there is no capacity for
+        // the stream to send the data, which attempts to place the stream in pending_send.
+        // If the stream is not open, we don't want the stream to be scheduled for
+        // execution (pending_send). Note that if the stream is in pending_open, it will be
+        // pushed to pending_send when there is room for an open stream.
+        //
+        // In pending_push we track whether a PushPromise still needs to be sent
+        // from a different stream before we can start sending frames on this one.
+        // This is different from the "open" check because reserved streams don't count
+        // toward the concurrency limit.
+        // See https://httpwg.org/specs/rfc7540.html#rfc.section.5.1.2
+        !self.is_pending_open && !self.is_pending_push
+    }
+
+    /// Returns true if the stream is closed
+    pub fn is_closed(&self) -> bool {
+        // The state has fully transitioned to closed.
+        self.state.is_closed() &&
+            // Because outbound frames transition the stream state before being
+            // buffered, we have to ensure that all frames have been flushed.
+            self.pending_send.is_empty() &&
+            // Sometimes large data frames are sent out in chunks. After a chunk
+            // of the frame is sent, the remainder is pushed back onto the send
+            // queue to be rescheduled.
+            //
+            // Checking for additional buffered data lets us catch this case.
+            self.buffered_send_data == 0
+    }
+
+    /// Returns true if the stream is no longer in use
+    pub fn is_released(&self) -> bool {
+        // The stream is closed and fully flushed
+        self.is_closed() &&
+            // There are no more outstanding references to the stream
+            self.ref_count == 0 &&
+            // The stream is not in any queue
+            !self.is_pending_send && !self.is_pending_send_capacity &&
+            !self.is_pending_accept && !self.is_pending_window_update &&
+            !self.is_pending_open && self.reset_at.is_none()
+    }
+
+    /// Returns true when the consumer of the stream has dropped all handles
+    /// (indicating no further interest in the stream) and the stream state is
+    /// not actually closed.
+    ///
+    /// In this case, a reset should be sent.
+    pub fn is_canceled_interest(&self) -> bool {
+        self.ref_count == 0 && !self.state.is_closed()
+    }
+
+    /// Current available stream send capacity
+    pub fn capacity(&self, max_buffer_size: usize) -> WindowSize {
+        let available = self.send_flow.available().as_size() as usize;
+        let buffered = self.buffered_send_data;
+
+        available.min(max_buffer_size).saturating_sub(buffered) as WindowSize
+    }
+
+    pub fn assign_capacity(&mut self, capacity: WindowSize, max_buffer_size: usize) {
+        let prev_capacity = self.capacity(max_buffer_size);
+        debug_assert!(capacity > 0);
+        // TODO: proper error handling
+        let _res = self.send_flow.assign_capacity(capacity);
+        debug_assert!(_res.is_ok());
+
+        tracing::trace!(
+            "  assigned capacity to stream; available={}; buffered={}; id={:?}; max_buffer_size={} prev={}",
+            self.send_flow.available(),
+            self.buffered_send_data,
+            self.id,
+            max_buffer_size,
+            prev_capacity,
+        );
+
+        if prev_capacity < self.capacity(max_buffer_size) {
+            self.notify_capacity();
+        }
+    }
+
+    pub fn send_data(&mut self, len: WindowSize, max_buffer_size: usize) {
+        let prev_capacity = self.capacity(max_buffer_size);
+
+        // TODO: proper error handling
+        let _res = self.send_flow.send_data(len);
+        debug_assert!(_res.is_ok());
+
+        // Decrement the stream's buffered data counter
+        debug_assert!(self.buffered_send_data >= len as usize);
+        self.buffered_send_data -= len as usize;
+        self.requested_send_capacity -= len;
+
+        tracing::trace!(
+            "  sent stream data; available={}; buffered={}; id={:?}; max_buffer_size={} prev={}",
+            self.send_flow.available(),
+            self.buffered_send_data,
+            self.id,
+            max_buffer_size,
+            prev_capacity,
+        );
+
+        if prev_capacity < self.capacity(max_buffer_size) {
+            self.notify_capacity();
+        }
+    }
+
+    /// If the capacity was limited because of the max_send_buffer_size,
+    /// then consider waking the send task again...
+    pub fn notify_capacity(&mut self) {
+        self.send_capacity_inc = true;
+        tracing::trace!("  notifying task");
+        self.notify_send();
+    }
+
+    /// Returns `Err` when the decrement cannot be completed due to overflow.
+    pub fn dec_content_length(&mut self, len: usize) -> Result<(), ()> {
+        match self.content_length {
+            ContentLength::Remaining(ref mut rem) => match rem.checked_sub(len as u64) {
+                Some(val) => *rem = val,
+                None => return Err(()),
+            },
+            ContentLength::Head => {
+                if len != 0 {
+                    return Err(());
+                }
+            }
+            _ => {}
+        }
+
+        Ok(())
+    }
+
+    pub fn ensure_content_length_zero(&self) -> Result<(), ()> {
+        match self.content_length {
+            ContentLength::Remaining(0) => Ok(()),
+            ContentLength::Remaining(_) => Err(()),
+            _ => Ok(()),
+        }
+    }
+
+    pub fn notify_send(&mut self) {
+        if let Some(task) = self.send_task.take() {
+            task.wake();
+        }
+    }
+
+    pub fn wait_send(&mut self, cx: &Context) {
+        self.send_task = Some(cx.waker().clone());
+    }
+
+    pub fn notify_recv(&mut self) {
+        if let Some(task) = self.recv_task.take() {
+            task.wake();
+        }
+    }
+
+    pub(super) fn notify_push(&mut self) {
+        if let Some(task) = self.push_task.take() {
+            task.wake();
+        }
+    }
+
+    /// Set the stream's state to `Closed` with the given reason and initiator.
+    /// Notify the send and receive tasks, if they exist.
+    pub(super) fn set_reset(&mut self, reason: Reason, initiator: Initiator) {
+        self.state.set_reset(self.id, reason, initiator);
+        self.notify_push();
+        self.notify_recv();
+    }
+}
+
+impl fmt::Debug for Stream {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Stream")
+            .field("id", &self.id)
+            .field("state", &self.state)
+            .field("is_counted", &self.is_counted)
+            .field("ref_count", &self.ref_count)
+            .h2_field_some("next_pending_send", &self.next_pending_send)
+            .h2_field_if("is_pending_send", &self.is_pending_send)
+            .field("send_flow", &self.send_flow)
+            .field("requested_send_capacity", &self.requested_send_capacity)
+            .field("buffered_send_data", &self.buffered_send_data)
+            .h2_field_some("send_task", &self.send_task.as_ref().map(|_| ()))
+            .h2_field_if_then(
+                "pending_send",
+                !self.pending_send.is_empty(),
+                &self.pending_send,
+            )
+            .h2_field_some(
+                "next_pending_send_capacity",
+                &self.next_pending_send_capacity,
+            )
+            .h2_field_if("is_pending_send_capacity", &self.is_pending_send_capacity)
+            .h2_field_if("send_capacity_inc", &self.send_capacity_inc)
+            .h2_field_some("next_open", &self.next_open)
+            .h2_field_if("is_pending_open", &self.is_pending_open)
+            .h2_field_if("is_pending_push", &self.is_pending_push)
+            .h2_field_some("next_pending_accept", &self.next_pending_accept)
+            .h2_field_if("is_pending_accept", &self.is_pending_accept)
+            .field("recv_flow", &self.recv_flow)
+            .field("in_flight_recv_data", &self.in_flight_recv_data)
+            .h2_field_some("next_window_update", &self.next_window_update)
+            .h2_field_if("is_pending_window_update", &self.is_pending_window_update)
+            .h2_field_some("reset_at", &self.reset_at)
+            .h2_field_some("next_reset_expire", &self.next_reset_expire)
+            .h2_field_if_then(
+                "pending_recv",
+                !self.pending_recv.is_empty(),
+                &self.pending_recv,
+            )
+            .h2_field_if("is_recv", &self.is_recv)
+            .h2_field_some("recv_task", &self.recv_task.as_ref().map(|_| ()))
+            .h2_field_some("push_task", &self.push_task.as_ref().map(|_| ()))
+            .h2_field_if_then(
+                "pending_push_promises",
+                !self.pending_push_promises.is_empty(),
+                &self.pending_push_promises,
+            )
+            .field("content_length", &self.content_length)
+            .finish()
+    }
+}
+
+impl store::Next for NextAccept {
+    fn next(stream: &Stream) -> Option<store::Key> {
+        stream.next_pending_accept
+    }
+
+    fn set_next(stream: &mut Stream, key: Option<store::Key>) {
+        stream.next_pending_accept = key;
+    }
+
+    fn take_next(stream: &mut Stream) -> Option<store::Key> {
+        stream.next_pending_accept.take()
+    }
+
+    fn is_queued(stream: &Stream) -> bool {
+        stream.is_pending_accept
+    }
+
+    fn set_queued(stream: &mut Stream, val: bool) {
+        stream.is_pending_accept = val;
+    }
+}
+
+impl store::Next for NextSend {
+    fn next(stream: &Stream) -> Option<store::Key> {
+        stream.next_pending_send
+    }
+
+    fn set_next(stream: &mut Stream, key: Option<store::Key>) {
+        stream.next_pending_send = key;
+    }
+
+    fn take_next(stream: &mut Stream) -> Option<store::Key> {
+        stream.next_pending_send.take()
+    }
+
+    fn is_queued(stream: &Stream) -> bool {
+        stream.is_pending_send
+    }
+
+    fn set_queued(stream: &mut Stream, val: bool) {
+        if val {
+            // ensure that stream is not queued for being opened
+            // if it's being put into queue for sending data
+            debug_assert!(!stream.is_pending_open);
+        }
+        stream.is_pending_send = val;
+    }
+}
+
+impl store::Next for NextSendCapacity {
+    fn next(stream: &Stream) -> Option<store::Key> {
+        stream.next_pending_send_capacity
+    }
+
+    fn set_next(stream: &mut Stream, key: Option<store::Key>) {
+        stream.next_pending_send_capacity = key;
+    }
+
+    fn take_next(stream: &mut Stream) -> Option<store::Key> {
+        stream.next_pending_send_capacity.take()
+    }
+
+    fn is_queued(stream: &Stream) -> bool {
+        stream.is_pending_send_capacity
+    }
+
+    fn set_queued(stream: &mut Stream, val: bool) {
+        stream.is_pending_send_capacity = val;
+    }
+}
+
+impl store::Next for NextWindowUpdate {
+    fn next(stream: &Stream) -> Option<store::Key> {
+        stream.next_window_update
+    }
+
+    fn set_next(stream: &mut Stream, key: Option<store::Key>) {
+        stream.next_window_update = key;
+    }
+
+    fn take_next(stream: &mut Stream) -> Option<store::Key> {
+        stream.next_window_update.take()
+    }
+
+    fn is_queued(stream: &Stream) -> bool {
+        stream.is_pending_window_update
+    }
+
+    fn set_queued(stream: &mut Stream, val: bool) {
+        stream.is_pending_window_update = val;
+    }
+}
+
+impl store::Next for NextOpen {
+    fn next(stream: &Stream) -> Option<store::Key> {
+        stream.next_open
+    }
+
+    fn set_next(stream: &mut Stream, key: Option<store::Key>) {
+        stream.next_open = key;
+    }
+
+    fn take_next(stream: &mut Stream) -> Option<store::Key> {
+        stream.next_open.take()
+    }
+
+    fn is_queued(stream: &Stream) -> bool {
+        stream.is_pending_open
+    }
+
+    fn set_queued(stream: &mut Stream, val: bool) {
+        if val {
+            // ensure that stream is not queued for being sent
+            // if it's being put into queue for opening the stream
+            debug_assert!(!stream.is_pending_send);
+        }
+        stream.is_pending_open = val;
+    }
+}
+
+impl store::Next for NextResetExpire {
+    fn next(stream: &Stream) -> Option<store::Key> {
+        stream.next_reset_expire
+    }
+
+    fn set_next(stream: &mut Stream, key: Option<store::Key>) {
+        stream.next_reset_expire = key;
+    }
+
+    fn take_next(stream: &mut Stream) -> Option<store::Key> {
+        stream.next_reset_expire.take()
+    }
+
+    fn is_queued(stream: &Stream) -> bool {
+        stream.reset_at.is_some()
+    }
+
+    fn set_queued(stream: &mut Stream, val: bool) {
+        if val {
+            stream.reset_at = Some(Instant::now());
+        } else {
+            stream.reset_at = None;
+        }
+    }
+}
+
+// ===== impl ContentLength =====
+
+impl ContentLength {
+    pub fn is_head(&self) -> bool {
+        matches!(*self, Self::Head)
+    }
+}

vendor/h2/src/share.rs

@@ -0,0 +1,606 @@
+use crate::codec::UserError;
+use crate::frame::Reason;
+use crate::proto::{self, WindowSize};
+
+use bytes::{Buf, Bytes};
+use http::HeaderMap;
+
+use std::fmt;
+#[cfg(feature = "stream")]
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+/// Sends the body stream and trailers to the remote peer.
+///
+/// # Overview
+///
+/// A `SendStream` is provided by [`SendRequest`] and [`SendResponse`] once the
+/// HTTP/2 message header has been sent sent. It is used to stream the message
+/// body and send the message trailers. See method level documentation for more
+/// details.
+///
+/// The `SendStream` instance is also used to manage outbound flow control.
+///
+/// If a `SendStream` is dropped without explicitly closing the send stream, a
+/// `RST_STREAM` frame will be sent. This essentially cancels the request /
+/// response exchange.
+///
+/// The ways to explicitly close the send stream are:
+///
+/// * Set `end_of_stream` to true when calling [`send_request`],
+///   [`send_response`], or [`send_data`].
+/// * Send trailers with [`send_trailers`].
+/// * Explicitly reset the stream with [`send_reset`].
+///
+/// # Flow control
+///
+/// In HTTP/2, data cannot be sent to the remote peer unless there is
+/// available window capacity on both the stream and the connection. When a data
+/// frame is sent, both the stream window and the connection window are
+/// decremented. When the stream level window reaches zero, no further data can
+/// be sent on that stream. When the connection level window reaches zero, no
+/// further data can be sent on any stream for that connection.
+///
+/// When the remote peer is ready to receive more data, it sends `WINDOW_UPDATE`
+/// frames. These frames increment the windows. See the [specification] for more
+/// details on the principles of HTTP/2 flow control.
+///
+/// The implications for sending data are that the caller **should** ensure that
+/// both the stream and the connection has available window capacity before
+/// loading the data to send into memory. The `SendStream` instance provides the
+/// necessary APIs to perform this logic. This, however, is not an obligation.
+/// If the caller attempts to send data on a stream when there is no available
+/// window capacity, the library will buffer the data until capacity becomes
+/// available, at which point the buffer will be flushed to the connection.
+///
+/// **NOTE**: There is no bound on the amount of data that the library will
+/// buffer. If you are sending large amounts of data, you really should hook
+/// into the flow control lifecycle. Otherwise, you risk using up significant
+/// amounts of memory.
+///
+/// To hook into the flow control lifecycle, the caller signals to the library
+/// that it intends to send data by calling [`reserve_capacity`], specifying the
+/// amount of data, in octets, that the caller intends to send. After this,
+/// `poll_capacity` is used to be notified when the requested capacity is
+/// assigned to the stream. Once [`poll_capacity`] returns `Ready` with the number
+/// of octets available to the stream, the caller is able to actually send the
+/// data using [`send_data`].
+///
+/// Because there is also a connection level window that applies to **all**
+/// streams on a connection, when capacity is assigned to a stream (indicated by
+/// `poll_capacity` returning `Ready`), this capacity is reserved on the
+/// connection and will **not** be assigned to any other stream. If data is
+/// never written to the stream, that capacity is effectively lost to other
+/// streams and this introduces the risk of deadlocking a connection.
+///
+/// To avoid throttling data on a connection, the caller should not reserve
+/// capacity until ready to send data and once any capacity is assigned to the
+/// stream, the caller should immediately send data consuming this capacity.
+/// There is no guarantee as to when the full capacity requested will become
+/// available. For example, if the caller requests 64 KB of data and 512 bytes
+/// become available, the caller should immediately send 512 bytes of data.
+///
+/// See [`reserve_capacity`] documentation for more details.
+///
+/// [`SendRequest`]: client/struct.SendRequest.html
+/// [`SendResponse`]: server/struct.SendResponse.html
+/// [specification]: http://httpwg.org/specs/rfc7540.html#FlowControl
+/// [`reserve_capacity`]: #method.reserve_capacity
+/// [`poll_capacity`]: #method.poll_capacity
+/// [`send_data`]: #method.send_data
+/// [`send_request`]: client/struct.SendRequest.html#method.send_request
+/// [`send_response`]: server/struct.SendResponse.html#method.send_response
+/// [`send_data`]: #method.send_data
+/// [`send_trailers`]: #method.send_trailers
+/// [`send_reset`]: #method.send_reset
+#[derive(Debug)]
+pub struct SendStream<B> {
+    inner: proto::StreamRef<B>,
+}
+
+/// A stream identifier, as described in [Section 5.1.1] of RFC 7540.
+///
+/// Streams are identified with an unsigned 31-bit integer. Streams
+/// initiated by a client MUST use odd-numbered stream identifiers; those
+/// initiated by the server MUST use even-numbered stream identifiers.  A
+/// stream identifier of zero (0x0) is used for connection control
+/// messages; the stream identifier of zero cannot be used to establish a
+/// new stream.
+///
+/// [Section 5.1.1]: https://tools.ietf.org/html/rfc7540#section-5.1.1
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+pub struct StreamId(u32);
+
+impl From<StreamId> for u32 {
+    fn from(src: StreamId) -> Self {
+        src.0
+    }
+}
+
+/// Receives the body stream and trailers from the remote peer.
+///
+/// A `RecvStream` is provided by [`client::ResponseFuture`] and
+/// [`server::Connection`] with the received HTTP/2 message head (the response
+/// and request head respectively).
+///
+/// A `RecvStream` instance is used to receive the streaming message body and
+/// any trailers from the remote peer. It is also used to manage inbound flow
+/// control.
+///
+/// See method level documentation for more details on receiving data. See
+/// [`FlowControl`] for more details on inbound flow control.
+///
+/// [`client::ResponseFuture`]: client/struct.ResponseFuture.html
+/// [`server::Connection`]: server/struct.Connection.html
+/// [`FlowControl`]: struct.FlowControl.html
+/// [`Stream`]: https://docs.rs/futures/0.1/futures/stream/trait.Stream.html
+#[must_use = "streams do nothing unless polled"]
+pub struct RecvStream {
+    inner: FlowControl,
+}
+
+/// A handle to release window capacity to a remote stream.
+///
+/// This type allows the caller to manage inbound data [flow control]. The
+/// caller is expected to call [`release_capacity`] after dropping data frames.
+///
+/// # Overview
+///
+/// Each stream has a window size. This window size is the maximum amount of
+/// inbound data that can be in-flight. In-flight data is defined as data that
+/// has been received, but not yet released.
+///
+/// When a stream is created, the window size is set to the connection's initial
+/// window size value. When a data frame is received, the window size is then
+/// decremented by size of the data frame before the data is provided to the
+/// caller. As the caller finishes using the data, [`release_capacity`] must be
+/// called. This will then increment the window size again, allowing the peer to
+/// send more data.
+///
+/// There is also a connection level window as well as the stream level window.
+/// Received data counts against the connection level window as well and calls
+/// to [`release_capacity`] will also increment the connection level window.
+///
+/// # Sending `WINDOW_UPDATE` frames
+///
+/// `WINDOW_UPDATE` frames will not be sent out for **every** call to
+/// `release_capacity`, as this would end up slowing down the protocol. Instead,
+/// `h2` waits until the window size is increased to a certain threshold and
+/// then sends out a single `WINDOW_UPDATE` frame representing all the calls to
+/// `release_capacity` since the last `WINDOW_UPDATE` frame.
+///
+/// This essentially batches window updating.
+///
+/// # Scenarios
+///
+/// Following is a basic scenario with an HTTP/2 connection containing a
+/// single active stream.
+///
+/// * A new stream is activated. The receive window is initialized to 1024 (the
+///   value of the initial window size for this connection).
+/// * A `DATA` frame is received containing a payload of 600 bytes.
+/// * The receive window size is reduced to 424 bytes.
+/// * [`release_capacity`] is called with 200.
+/// * The receive window size is now 624 bytes. The peer may send no more than
+///   this.
+/// * A `DATA` frame is received with a payload of 624 bytes.
+/// * The window size is now 0 bytes. The peer may not send any more data.
+/// * [`release_capacity`] is called with 1024.
+/// * The receive window size is now 1024 bytes. The peer may now send more
+///   data.
+///
+/// [flow control]: ../index.html#flow-control
+/// [`release_capacity`]: struct.FlowControl.html#method.release_capacity
+#[derive(Clone, Debug)]
+pub struct FlowControl {
+    inner: proto::OpaqueStreamRef,
+}
+
+/// A handle to send and receive PING frames with the peer.
+// NOT Clone on purpose
+pub struct PingPong {
+    inner: proto::UserPings,
+}
+
+/// Sent via [`PingPong`][] to send a PING frame to a peer.
+///
+/// [`PingPong`]: struct.PingPong.html
+pub struct Ping {
+    _p: (),
+}
+
+/// Received via [`PingPong`][] when a peer acknowledges a [`Ping`][].
+///
+/// [`PingPong`]: struct.PingPong.html
+/// [`Ping`]: struct.Ping.html
+pub struct Pong {
+    _p: (),
+}
+
+// ===== impl SendStream =====
+
+impl<B: Buf> SendStream<B> {
+    pub(crate) fn new(inner: proto::StreamRef<B>) -> Self {
+        SendStream { inner }
+    }
+
+    /// Requests capacity to send data.
+    ///
+    /// This function is used to express intent to send data. This requests
+    /// connection level capacity. Once the capacity is available, it is
+    /// assigned to the stream and not reused by other streams.
+    ///
+    /// This function may be called repeatedly. The `capacity` argument is the
+    /// **total** amount of requested capacity. Sequential calls to
+    /// `reserve_capacity` are *not* additive. Given the following:
+    ///
+    /// ```rust
+    /// # use h2::*;
+    /// # fn doc(mut send_stream: SendStream<&'static [u8]>) {
+    /// send_stream.reserve_capacity(100);
+    /// send_stream.reserve_capacity(200);
+    /// # }
+    /// ```
+    ///
+    /// After the second call to `reserve_capacity`, the *total* requested
+    /// capacity will be 200.
+    ///
+    /// `reserve_capacity` is also used to cancel previous capacity requests.
+    /// Given the following:
+    ///
+    /// ```rust
+    /// # use h2::*;
+    /// # fn doc(mut send_stream: SendStream<&'static [u8]>) {
+    /// send_stream.reserve_capacity(100);
+    /// send_stream.reserve_capacity(0);
+    /// # }
+    /// ```
+    ///
+    /// After the second call to `reserve_capacity`, the *total* requested
+    /// capacity will be 0, i.e. there is no requested capacity for the stream.
+    ///
+    /// If `reserve_capacity` is called with a lower value than the amount of
+    /// capacity **currently** assigned to the stream, this capacity will be
+    /// returned to the connection to be re-assigned to other streams.
+    ///
+    /// Also, the amount of capacity that is reserved gets decremented as data
+    /// is sent. For example:
+    ///
+    /// ```rust
+    /// # use h2::*;
+    /// # async fn doc(mut send_stream: SendStream<&'static [u8]>) {
+    /// send_stream.reserve_capacity(100);
+    ///
+    /// send_stream.send_data(b"hello", false).unwrap();
+    /// // At this point, the total amount of requested capacity is 95 bytes.
+    ///
+    /// // Calling `reserve_capacity` with `100` again essentially requests an
+    /// // additional 5 bytes.
+    /// send_stream.reserve_capacity(100);
+    /// # }
+    /// ```
+    ///
+    /// See [Flow control](struct.SendStream.html#flow-control) for an overview
+    /// of how send flow control works.
+    pub fn reserve_capacity(&mut self, capacity: usize) {
+        // TODO: Check for overflow
+        self.inner.reserve_capacity(capacity as WindowSize)
+    }
+
+    /// Returns the stream's current send capacity.
+    ///
+    /// This allows the caller to check the current amount of available capacity
+    /// before sending data.
+    pub fn capacity(&self) -> usize {
+        self.inner.capacity() as usize
+    }
+
+    /// Requests to be notified when the stream's capacity increases.
+    ///
+    /// Before calling this, capacity should be requested with
+    /// `reserve_capacity`. Once capacity is requested, the connection will
+    /// assign capacity to the stream **as it becomes available**. There is no
+    /// guarantee as to when and in what increments capacity gets assigned to
+    /// the stream.
+    ///
+    /// To get notified when the available capacity increases, the caller calls
+    /// `poll_capacity`, which returns `Ready(Some(n))` when `n` has been
+    /// increased by the connection. Note that `n` here represents the **total**
+    /// amount of assigned capacity at that point in time. It is also possible
+    /// that `n` is lower than the previous call if, since then, the caller has
+    /// sent data.
+    pub fn poll_capacity(&mut self, cx: &mut Context) -> Poll<Option<Result<usize, crate::Error>>> {
+        self.inner
+            .poll_capacity(cx)
+            .map_ok(|w| w as usize)
+            .map_err(Into::into)
+    }
+
+    /// Sends a single data frame to the remote peer.
+    ///
+    /// This function may be called repeatedly as long as `end_of_stream` is set
+    /// to `false`. Setting `end_of_stream` to `true` sets the end stream flag
+    /// on the data frame. Any further calls to `send_data` or `send_trailers`
+    /// will return an [`Error`].
+    ///
+    /// `send_data` can be called without reserving capacity. In this case, the
+    /// data is buffered and the capacity is implicitly requested. Once the
+    /// capacity becomes available, the data is flushed to the connection.
+    /// However, this buffering is unbounded. As such, sending large amounts of
+    /// data without reserving capacity before hand could result in large
+    /// amounts of data being buffered in memory.
+    ///
+    /// [`Error`]: struct.Error.html
+    pub fn send_data(&mut self, data: B, end_of_stream: bool) -> Result<(), crate::Error> {
+        self.inner
+            .send_data(data, end_of_stream)
+            .map_err(Into::into)
+    }
+
+    /// Sends trailers to the remote peer.
+    ///
+    /// Sending trailers implicitly closes the send stream. Once the send stream
+    /// is closed, no more data can be sent.
+    pub fn send_trailers(&mut self, trailers: HeaderMap) -> Result<(), crate::Error> {
+        self.inner.send_trailers(trailers).map_err(Into::into)
+    }
+
+    /// Resets the stream.
+    ///
+    /// This cancels the request / response exchange. If the response has not
+    /// yet been received, the associated `ResponseFuture` will return an
+    /// [`Error`] to reflect the canceled exchange.
+    ///
+    /// [`Error`]: struct.Error.html
+    pub fn send_reset(&mut self, reason: Reason) {
+        self.inner.send_reset(reason)
+    }
+
+    /// Polls to be notified when the client resets this stream.
+    ///
+    /// If stream is still open, this returns `Poll::Pending`, and
+    /// registers the task to be notified if a `RST_STREAM` is received.
+    ///
+    /// If a `RST_STREAM` frame is received for this stream, calling this
+    /// method will yield the `Reason` for the reset.
+    ///
+    /// # Error
+    ///
+    /// If connection sees an error, this returns that error instead of a
+    /// `Reason`.
+    pub fn poll_reset(&mut self, cx: &mut Context) -> Poll<Result<Reason, crate::Error>> {
+        self.inner.poll_reset(cx, proto::PollReset::Streaming)
+    }
+
+    /// Returns the stream ID of this `SendStream`.
+    ///
+    /// # Panics
+    ///
+    /// If the lock on the stream store has been poisoned.
+    pub fn stream_id(&self) -> StreamId {
+        StreamId::from_internal(self.inner.stream_id())
+    }
+}
+
+// ===== impl StreamId =====
+
+impl StreamId {
+    pub(crate) fn from_internal(id: crate::frame::StreamId) -> Self {
+        StreamId(id.into())
+    }
+
+    /// Returns the `u32` corresponding to this `StreamId`
+    ///
+    /// # Note
+    ///
+    /// This is the same as the `From<StreamId>` implementation, but
+    /// included as an inherent method because that implementation doesn't
+    /// appear in rustdocs, as well as a way to force the type instead of
+    /// relying on inference.
+    pub fn as_u32(&self) -> u32 {
+        (*self).into()
+    }
+}
+// ===== impl RecvStream =====
+
+impl RecvStream {
+    pub(crate) fn new(inner: FlowControl) -> Self {
+        RecvStream { inner }
+    }
+
+    /// Get the next data frame.
+    pub async fn data(&mut self) -> Option<Result<Bytes, crate::Error>> {
+        crate::poll_fn(move |cx| self.poll_data(cx)).await
+    }
+
+    /// Get optional trailers for this stream.
+    pub async fn trailers(&mut self) -> Result<Option<HeaderMap>, crate::Error> {
+        crate::poll_fn(move |cx| self.poll_trailers(cx)).await
+    }
+
+    /// Poll for the next data frame.
+    pub fn poll_data(&mut self, cx: &mut Context<'_>) -> Poll<Option<Result<Bytes, crate::Error>>> {
+        self.inner.inner.poll_data(cx).map_err(Into::into)
+    }
+
+    #[doc(hidden)]
+    pub fn poll_trailers(
+        &mut self,
+        cx: &mut Context,
+    ) -> Poll<Result<Option<HeaderMap>, crate::Error>> {
+        match ready!(self.inner.inner.poll_trailers(cx)) {
+            Some(Ok(map)) => Poll::Ready(Ok(Some(map))),
+            Some(Err(e)) => Poll::Ready(Err(e.into())),
+            None => Poll::Ready(Ok(None)),
+        }
+    }
+
+    /// Returns true if the receive half has reached the end of stream.
+    ///
+    /// A return value of `true` means that calls to `poll` and `poll_trailers`
+    /// will both return `None`.
+    pub fn is_end_stream(&self) -> bool {
+        self.inner.inner.is_end_stream()
+    }
+
+    /// Get a mutable reference to this stream's `FlowControl`.
+    ///
+    /// It can be used immediately, or cloned to be used later.
+    pub fn flow_control(&mut self) -> &mut FlowControl {
+        &mut self.inner
+    }
+
+    /// Returns the stream ID of this stream.
+    ///
+    /// # Panics
+    ///
+    /// If the lock on the stream store has been poisoned.
+    pub fn stream_id(&self) -> StreamId {
+        self.inner.stream_id()
+    }
+}
+
+#[cfg(feature = "stream")]
+impl futures_core::Stream for RecvStream {
+    type Item = Result<Bytes, crate::Error>;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        self.poll_data(cx)
+    }
+}
+
+impl fmt::Debug for RecvStream {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.debug_struct("RecvStream")
+            .field("inner", &self.inner)
+            .finish()
+    }
+}
+
+impl Drop for RecvStream {
+    fn drop(&mut self) {
+        // Eagerly clear any received DATA frames now, since its no longer
+        // possible to retrieve them. However, this will be called
+        // again once *all* stream refs have been dropped, since
+        // this won't send a RST_STREAM frame, in case the user wishes to
+        // still *send* DATA.
+        self.inner.inner.clear_recv_buffer();
+    }
+}
+
+// ===== impl FlowControl =====
+
+impl FlowControl {
+    pub(crate) fn new(inner: proto::OpaqueStreamRef) -> Self {
+        FlowControl { inner }
+    }
+
+    /// Returns the stream ID of the stream whose capacity will
+    /// be released by this `FlowControl`.
+    pub fn stream_id(&self) -> StreamId {
+        StreamId::from_internal(self.inner.stream_id())
+    }
+
+    /// Get the current available capacity of data this stream *could* receive.
+    pub fn available_capacity(&self) -> isize {
+        self.inner.available_recv_capacity()
+    }
+
+    /// Get the currently *used* capacity for this stream.
+    ///
+    /// This is the amount of bytes that can be released back to the remote.
+    pub fn used_capacity(&self) -> usize {
+        self.inner.used_recv_capacity() as usize
+    }
+
+    /// Release window capacity back to remote stream.
+    ///
+    /// This releases capacity back to the stream level and the connection level
+    /// windows. Both window sizes will be increased by `sz`.
+    ///
+    /// See [struct level] documentation for more details.
+    ///
+    /// # Errors
+    ///
+    /// This function errors if increasing the receive window size by `sz` would
+    /// result in a window size greater than the target window size. In other
+    /// words, the caller cannot release more capacity than data has been
+    /// received. If 1024 bytes of data have been received, at most 1024 bytes
+    /// can be released.
+    ///
+    /// [struct level]: #
+    pub fn release_capacity(&mut self, sz: usize) -> Result<(), crate::Error> {
+        if sz > proto::MAX_WINDOW_SIZE as usize {
+            return Err(UserError::ReleaseCapacityTooBig.into());
+        }
+        self.inner
+            .release_capacity(sz as proto::WindowSize)
+            .map_err(Into::into)
+    }
+}
+
+// ===== impl PingPong =====
+
+impl PingPong {
+    pub(crate) fn new(inner: proto::UserPings) -> Self {
+        PingPong { inner }
+    }
+
+    /// Send a PING frame and wait for the peer to send the pong.
+    pub async fn ping(&mut self, ping: Ping) -> Result<Pong, crate::Error> {
+        self.send_ping(ping)?;
+        crate::poll_fn(|cx| self.poll_pong(cx)).await
+    }
+
+    #[doc(hidden)]
+    pub fn send_ping(&mut self, ping: Ping) -> Result<(), crate::Error> {
+        // Passing a `Ping` here is just to be forwards-compatible with
+        // eventually allowing choosing a ping payload. For now, we can
+        // just ignore it.
+        let _ = ping;
+
+        self.inner.send_ping().map_err(|err| match err {
+            Some(err) => err.into(),
+            None => UserError::SendPingWhilePending.into(),
+        })
+    }
+
+    #[doc(hidden)]
+    pub fn poll_pong(&mut self, cx: &mut Context) -> Poll<Result<Pong, crate::Error>> {
+        ready!(self.inner.poll_pong(cx))?;
+        Poll::Ready(Ok(Pong { _p: () }))
+    }
+}
+
+impl fmt::Debug for PingPong {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.debug_struct("PingPong").finish()
+    }
+}
+
+// ===== impl Ping =====
+
+impl Ping {
+    /// Creates a new opaque `Ping` to be sent via a [`PingPong`][].
+    ///
+    /// The payload is "opaque", such that it shouldn't be depended on.
+    ///
+    /// [`PingPong`]: struct.PingPong.html
+    pub fn opaque() -> Ping {
+        Ping { _p: () }
+    }
+}
+
+impl fmt::Debug for Ping {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.debug_struct("Ping").finish()
+    }
+}
+
+// ===== impl Pong =====
+
+impl fmt::Debug for Pong {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.debug_struct("Pong").finish()
+    }
+}