- LocalBackend: flat {hex-prefix}/{hex-prefix}/{hex} sharding over
lowercase-hex-of-Key::as_bytes filenames (self-describing; the
list-decode round-trip recorded for the review gate); virgin-store
reads are no-ops
- staged put: unique stage files under {root}/staging/, commit-rename
is the publish, CAS first-writer-wins, every failure path (discard,
failed commit, Drop cancellation) converges on zero residue
- read cursor: pread loop over the immutable committed file, EOF
clamping, provided read_range composing the slice-digest convention
- all file I/O in spawn_blocking; size is a stat, never a content load
- list walks the committed tree and is fatal (Error::Io, path named)
on anything that does not decode — complete and well-formed
- 11 in-module unit tests incl. exact-count stage hygiene over all
failure forms and the success form
Verification: cargo test (44 green), clippy --all-targets/--all-features
-D warnings, fmt --check — all clean
Task: tasks/engine-local.md
Nine tasks against the wave-1 contract surface as reviewed (no
amendments from the gate):
- engine-mem / engine-local (parallel, dependency-free): the two
engines; local owns the stage-hygiene exact-count tests and the
Drop-cancellation story the wave-1 review recorded
- store-construction: the Store type, constructor modes, size-threshold
dispatch; binds the conformance factory's Store associated type
- store-read-paths ∥ gc-protocol: read ops with the ADR-012 §6.1
fall-through rule; the ADR-005 in-process protocol (pins, liveness,
delete windows, abort-as-data, GcRefuse with the full protection set)
- store-put-paths: the two put paths behind one signature, ADR-003's
three numbered rules, pin-before-publish, Batch, kv-only rejection
- suite-column-mem → suite-column-local: the reference column, then the
dual-tier dispatch-coverage shape mirroring it
- review-wave-2: the gate (facade/dispatch/GC vs ADR-003/005/012)
Verification: dependency graph validated (all ids resolve, no cycles,
topological order clean); docs-only change.
Refs: docs/plans/implementation.md §Wave 2
glm-5.3-flash