- KvEngine::Sqlite slots in; all six kv ops dispatch; the kv cursor
body dispatches through a new KvCursor sub-enum behind AnyCursor's
one kv arm (the kv-arm-over-multiple-kv-engines design point,
recorded)
- dual_tier_sqlite_local (kv = sqlite + large = local, the
default-build production shape) and kv_only_sqlite constructors —
both feature-gated on sqlite (default-on), both taking the
threshold and the delete-window delay, fallible where I/O is
fallible (Err(Error::Io) per the dual_tier_mem_local pattern)
- ensure_gc_schema runs at construction via the engine-neutral
KvEngine call (sqlite's body creates gc_window only); the
window-delay shipped default is the pinned
DEFAULT_DELETE_WINDOW_DELAY (5 min, ADR-008 §2), constructor-
tunable, Duration::ZERO legal — the store carries the value for
the sweep's durable form to consume
- the one-window-host posture recorded in the module doc (the
durable window hosts on the kv engine when it is SQL-backed; wave
5's pg-lo dormancy slots in without reshaping)
- stale empty-set scaffolding updated to the landed state: the
#[allow(unused_variables)] attrs off the KvEngine methods; the
scope notes in store.rs, backend.rs, sqlite.rs, gc.rs
- constructor unit tests: mode/threshold/window-delay introspection,
the GC schema observed in the fresh database (window table present,
gc_pins never), kv-only rejection wiring unchanged, and the
dual-tier shape round-tripping end-to-end through both tiers
Verification: cargo test 62 passed (default; 5 new tests), cargo test
--all-features 117, cargo test --features mem 117, --no-default-
features --features mem 97; cargo clippy --all-targets -- -D warnings
clean (default + all-features); cargo fmt --check clean; cargo doc
--no-deps at the pre-existing warning baseline.
Six tasks against the wave-2 contract surface as reviewed (no
amendments from the gate):
- engine-sqlite: the default kv engine — WAL + synchronous=NORMAL,
prepared statements, the indexed size column probe (B5's row shape),
has-as-EXISTS, virgin-store no-tables-yet tolerance, spawn_blocking
discipline
- engine-sqlite-window: the engine-state seam's window family only
(ADR-012 §5's reduction — gc_window, stage/take; no pin rows, no
sweep-lock body)
- store-sqlite-construction: KvEngine::Sqlite slots in, the
dual-tier/kv-only constructors with the constructor-tunable window
delay (default 5 min), ensure_gc_schema at construction, the
one-window-host posture
- store-sweep-durable-window: the sweep's SQL-backed form — overdue
rows execute with re-arbitration before/alongside marking, candidates
stage at mark_end + window, counts exact relative to the schedule
(ADR-012 §6.7); the inline form preserved verbatim
- suite-column-sqlite: the first SQL-backed column, server-less —
form-independent reference rows mirror directly; the sweep rows are
schedule-relative (the recorded INV-4/5 mirror amendment)
- review-wave-3: the engine-wave gate (engine-vs-contract conformance)
Verification: dependency graph validated (all ids resolve, no cycles,
topological order clean); docs-only change.
Refs: docs/plans/implementation.md §Wave 3
glm-5.3-flash