feat(storage): clear_caches() for out-of-band snapshot restore in tests#70
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…restore The process-wide SharedLoadCache (L2) outlives a ZODB.DB connection pool and uses a strictly monotonic consensus TID. Test harnesses that roll the database backwards out of band (snapshot restore between tests) leave it serving object state at TIDs newer than the rolled-back DB, causing a spurious ConflictError on the next commit. Add public PGJsonbStorage.clear_caches() and SharedLoadCache.clear() to drop all in-memory caches and reset the consensus TID. Not needed in production, where TIDs never decrease. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Problem
The process-wide
SharedLoadCache(L2, added in 1.12.0 / #63) outlives aZODB.DBconnection pool and uses a strictly monotonic consensus TID. Test harnesses that roll the database backwards out of band — e.g. restoring a snapshot between tests (PGTestDB.restore()doesDELETE+COPYof baseline rows at their original, lower TIDs) — leave the shared cache serving object state at TIDs newer than the rolled-back DB. The next commit then conflict-checks the in-memory_serial(newer) against the DB row (older) and raises a spurious, unresolvableConflictError.This surfaced downstream in
plone.pgcatalog: twoclearFindAndRebuildintegration tests fail withConflictErroronProducts.ZCTextIndex...PLexiconwhenever a rebuild test runs after another rebuild test. Green before 1.12.0 (no shared cache), red after.Fix
Add two public methods:
SharedLoadCache.clear()— drop all entries and reset_consensus_tidtoNone, so the nextpoll_advancere-establishes consensus from the (lower) current TID.PGJsonbStorage.clear_caches()— reset the shared L2 cache, the main L1 load cache, and the serial cache.In production TIDs never decrease (pack never lowers a live object's TID), so this is not part of the normal code path — it is a hook for test harnesses doing out-of-band rollbacks.
Tests
TDD:
tests/test_shared_load_cache.pygainsTestClear(incl. a backwards-TID regression: afterclear(), a lower TID is accepted again) and a storage-levelclear_caches()test.🤖 Generated with Claude Code