Auto-fmt nit on the multi-line map.flush() expression that landed
when the sweep + patch + DiscStream-FrameSource branches were merged
together. No semantic change.
Patch was strictly serial (per-sector recovery: read → seek+write
→ mapfile.record → next). Lifting the write+record onto a consumer
thread lets the drive issue the next per-sector retry while the
previous block's recovered bytes are being committed — small but
real win on damaged discs with many bad sectors, and uniform with
sweep's threading model.
- New PatchSink: Sink<PatchItem> impl in src/disc/patch.rs. Owns
WritebackFile + Mapfile. apply() seeks+writes recovered bytes
and records mapfile state per item; close() runs sync_all and
mapfile.flush.
- Channel depth: WRITE_THROUGH_DEPTH (1). Patch wants minimum
buffering — back-pressure should kick in immediately so the
drive's per-sector retry budget isn't ahead of the writer.
- Disc::patch: keeps every existing recovery decision on the
producer (reverse walk, damage-window skip, NOT_READY pauses,
bridge-degradation handling, wedge exit, range watchdog).
WritebackFile ownership moves to the sink.
Behaviour-preserving: per-sector single-shot read budget unchanged
(BU40N+Initio bridge wedge concern still respected); recovery
algorithm bit-identical.
See (internal)/memory/0_18_redesign.md.
Single contributor: MattJackson.
MattJackson