ValkeyLockProvider: SET NX EX for acquisition, Lua script for safe release.
ValkeyQueueProvider: LPUSH/RPOP for FIFO queues.
ValkeyLifecyclePublisher: PUBLISH to per-instance and global channels.
Connections obtained once during construction (no per-operation TCP handshakes).
PostgresPersistenceProvider using sqlx with wfc schema. JSONB for
complex fields, TIMESTAMPTZ for dates. Transactions for atomicity.
Proper error propagation on deserialization (no unwrap_or_default).
Status conversion returns Result for unknown values.
SqlitePersistenceProvider using sqlx with in-memory and file-based
SQLite. Schema with 6 tables, 8 indexes, created via ensure_store_exists.
Transactions for multi-table operations. Passes persistence_suite tests.
WorkflowHost orchestrates the engine: background workflow and event
consumers, start/stop lifecycle, workflow CRUD, event publishing.
WorkflowHostBuilder (owned-self, returns Result).
InMemoryWorkflowRegistry with version support. SyncWorkflowRunner
for testing. WorkflowPurger stub.
Event consumer acquires distributed locks before modifying workflows
to prevent lost updates from concurrent event processing.
InMemoryPersistenceProvider, InMemoryLockProvider, InMemoryQueueProvider,
InMemoryLifecyclePublisher behind test-support feature flag.
Shared test suite macros: persistence_suite!, lock_suite!, queue_suite!
that run the same tests against any provider implementation.
Workspace with 6 crates: wfe-core, wfe-sqlite, wfe-postgres,
wfe-opensearch, wfe-valkey, and wfe (umbrella). Nextest profiles
for default, integration, and CI. Docker compose for PostgreSQL,
Valkey, and OpenSearch integration tests.
