Struct RetrievalFailureLogger 

pub struct RetrievalFailureLogger { /* private fields */ }

Async background writer that batches retrieval failure records to SQLite.

Construct with RetrievalFailureLogger::new and call RetrievalFailureLogger::log from the recall hot path. Records are sent via a bounded channel; if the channel is full the record is silently dropped (zero hot-path latency, per INV-1).

The background writer task is registered with TaskSupervisor for lifecycle visibility and graceful shutdown. Call shutdown for a clean drain.

Implementations

impl RetrievalFailureLogger

pub fn new( sqlite: SqliteStore, channel_capacity: usize, batch_size: usize, flush_interval: Duration, retention_days: u32, supervisor: &TaskSupervisor, ) -> Self

Spawn the background writer task under supervisor and return a logger handle.

batch_size records are flushed at once, or after flush_interval elapses, whichever comes first. Old records are purged every CLEANUP_FLUSH_INTERVAL batch flushes according to retention_days.

pub fn log(&self, record: RetrievalFailureRecord)

Queue a retrieval failure record for async persistence.

Both query_text (512 chars) and error_context (256 chars) are truncated before enqueueing to bound in-channel memory usage (INV-3). If the channel is full the record is dropped and a debug message is emitted (INV-1).

pub async fn shutdown(self)

Drain queued records and wait for the writer to flush before returning.

Drops the sender so writer_task exits its receive loop, flushes the remaining batch, and fires the done notify. TaskSupervisor::shutdown_all should be called after this to clean up the registry entry.