Integrate nix::errno into Error.

Split sys/limits.rs; float dep:nix version.

Signed-off-by: Jason Volk <jason@zemos.net>

Cargo.toml

@@ -274,7 +274,7 @@ version = "0.6"
 features = ["std"]
 
 [workspace.dependencies.nix]
-version = "0.30"
+version = "0"
 default-features = false
 features = [
 	"resource",

src/core/error/mod.rs

@@ -52,6 +52,9 @@ pub enum Error {
 	CargoToml(#[from] cargo_toml::Error),
 	#[error(transparent)]
 	Clap(#[from] clap::error::Error),
+	#[cfg(unix)]
+	#[error(transparent)]
+	Errno(#[from] nix::errno::Errno),
 	#[error(transparent)]
 	Extension(#[from] axum::extract::rejection::ExtensionRejection),
 	#[error(transparent)]

src/core/utils/sys.rs

@@ -1,32 +1,11 @@
 pub mod compute;
+pub mod limits;
 pub mod storage;
 
 use std::path::PathBuf;
 
-pub use compute::available_parallelism;
-
-use crate::{Result, at, debug};
-
-/// This is needed for opening lots of file descriptors, which tends to
-/// happen more often when using RocksDB and making lots of federation
-/// connections at startup. The soft limit is usually 1024, and the hard
-/// limit is usually 512000; I've personally seen it hit >2000.
-///
-/// * <https://www.freedesktop.org/software/systemd/man/systemd.exec.html#id-1.12.2.1.17.6>
-/// * <https://github.com/systemd/systemd/commit/0abf94923b4a95a7d89bc526efc84e7ca2b71741>
-#[cfg(unix)]
-pub fn maximize_fd_limit() -> Result<(), nix::errno::Errno> {
-	use nix::sys::resource::{Resource::RLIMIT_NOFILE as NOFILE, getrlimit, setrlimit};
-
-	let (soft_limit, hard_limit) = getrlimit(NOFILE)?;
-	if soft_limit < hard_limit {
-		setrlimit(NOFILE, hard_limit, hard_limit)?;
-		assert_eq!((hard_limit, hard_limit), getrlimit(NOFILE)?, "getrlimit != setrlimit");
-		debug!(to = hard_limit, from = soft_limit, "Raised RLIMIT_NOFILE",);
-	}
-
-	Ok(())
-}
+pub use self::{compute::available_parallelism, limits::*};
+use crate::{Result, at};
 
 /// Return a possibly corrected std::env::current_exe() even if the path is
 /// marked deleted.

src/core/utils/sys/limits.rs

@@ -0,0 +1,36 @@
+#[cfg(unix)]
+use nix::sys::resource::{Resource, getrlimit};
+
+use crate::{Result, debug};
+
+/// This is needed for opening lots of file descriptors, which tends to
+/// happen more often when using RocksDB and making lots of federation
+/// connections at startup. The soft limit is usually 1024, and the hard
+/// limit is usually 512000; I've personally seen it hit >2000.
+///
+/// * <https://www.freedesktop.org/software/systemd/man/systemd.exec.html#id-1.12.2.1.17.6>
+/// * <https://github.com/systemd/systemd/commit/0abf94923b4a95a7d89bc526efc84e7ca2b71741>
+#[cfg(unix)]
+pub fn maximize_fd_limit() -> Result {
+	use nix::sys::resource::setrlimit;
+
+	let (soft_limit, hard_limit) = max_file_descriptors()?;
+	if soft_limit < hard_limit {
+		setrlimit(Resource::RLIMIT_NOFILE, hard_limit, hard_limit)?;
+		assert_eq!((hard_limit, hard_limit), max_file_descriptors()?, "getrlimit != setrlimit");
+		debug!(to = hard_limit, from = soft_limit, "Raised RLIMIT_NOFILE");
+	}
+
+	Ok(())
+}
+
+#[cfg(not(unix))]
+pub fn maximize_fd_limit() -> Result { Ok(()) }
+
+#[cfg(unix)]
+pub fn max_file_descriptors() -> Result<(u64, u64)> {
+	getrlimit(Resource::RLIMIT_NOFILE).map_err(Into::into)
+}
+
+#[cfg(not(unix))]
+pub fn max_file_descriptors() -> Result<(u64, u64)> { Ok((u64::MAX, u64::MAX)) }

src/main/server.rs

@@ -51,7 +51,6 @@ pub fn new(args: Option<&Args>, runtime: Option<&runtime::Handle>) -> Result<Arc
 	#[cfg(feature = "sentry_telemetry")]
 	let sentry_guard = crate::sentry::init(&config);
 
-	#[cfg(unix)]
 	sys::maximize_fd_limit()
 		.expect("Unable to increase maximum soft and hard file descriptor limit");