databasev2 2, task 5c step 2. The storage half the accessor was left waiting
for. Not yet wired into insert (that and 5d remain), and the loader still
refuses `resident: keys`, so nothing is exposed to a program yet.
- wo_db gains an `rt` back-pointer, set in main.c beside VM.rt.db. wo_rt
already carries `db` and `wal` as opaque handles, so this closes the loop
and a borrow can reach the log WITHOUT threading a wal pointer through
eleven call sites — which is the whole reason 5c is one accessor
- wo_row_drop_payload: the operation the plan recorded as MISSING. Frees the
slot and its engine-owned values, then re-points the id map at the record's
log offset (off + 1, reusing the same 0-is-empty trick as slot + 1). It
deliberately does NOT touch the secondary indexes (they store row ids, so
they stay correct), does NOT decrement count (the row is still live, only
its backing moved), and does NOT remove the id (that is how it is found)
- wo_row_borrow materialises for a keys table: reads the offset from the id
map, calls 5b's wo_wal_read_row_at into the per-table scratch, and checks
the record actually holds the expected class and id — a compaction that
moved records without rebuilding the map lands exactly there, which is the
obligation recorded at wo_wal_compact
- fully-resident tables keep today's path and pay one predicate
A REAL BUG, exposed the first time the path was used: wo_row_release freed the
materialised values with the ENGINE's allocator. They are VM values —
wo_wal_read_row_at is the out-gate and always copies — so ASan reported a
bad-free immediately. It now drops them through the runtime. That stub was
written in 5c step 1 for a path that did not exist yet.
Recorded while implementing: wo_wal_next_offset's contract says to trust an
offset "only after the matching commit returns 0". Group commit (databasev2 4)
defers that barrier to the drain, so db.c can no longer check inline — but part
A also made a failed commit FATAL, so no execution can record an offset whose
record never became durable. Same guarantee, different mechanism.
Test: a heap-valued row is inserted, committed, has its payload dropped, and is
read back out of the log with its Text intact; count is unchanged (still live);
and a second borrow succeeds, which fails if release did not clear the scratch.
Verified: just wovm-test — 36 suites 0 fail, test_wal 4273 pass, cli_smoke OK.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
(cherry picked from commit 125bd09218d616b2a16b140de770d3f38b45f0ac)
shoney.arickathil
7cc80405dd