The COW version-control surface (fork, branches, checkout, commit,
getHistory/streamHistory, asOfCommit, brain.versions) is gone, along with
its subsystems: src/versioning/, the COW object store (CommitLog,
CommitObject, RefManager, TreeObject), HistoricalStorageAdapter, and the
TypeAwareHNSWIndex path it kept alive. The Db API (now/transact/asOf/
with/persist/restore) is the one versioning model in 8.0.
Survivors and replacements:
- BlobStorage survives (the VFS stores file content through it), relocated
to src/storage/blobStorage.ts with binaryDataCodec.ts; its adapter
interface is now BlobStoreAdapter, slimmed to the consumed surface
(write/read/has/delete/getMetadata + MIME-aware compression policy).
- brain.migrate() backup branches are replaced by persist-before-migrate:
MigrateOptions.backupTo persists a hard-link snapshot of the current
generation before any transform runs; MigrationResult.backupPath reports
it, and brain.restore(path) brings it back wholesale.
- CLI: cow.ts (fork/branch/checkout/history/migrate) is replaced by
snapshot.ts — snapshot <path>, restore <path>, history (tx-log),
generation.
- New public read API: brain.transactionLog({limit}) exposes the reified
tx-log (generation/timestamp/meta, newest first) that backs the CLI
history command; TxLogEntry is exported.
Tests: superseded suites deleted; fork/commit blocks excised from shared
suites; BlobStorage tests relocated + reworked against the slimmed store;
migration tests now prove the backupTo snapshot/restore round trip; new
transactionLog coverage in db-mvcc.
GraphIndexProvider now speaks BigInt at the boundary (D.2 mirror):
- getNeighbors/getVerbIdsBySource/getVerbIdsByTarget take entity ints and
return entity/verb ints as bigint[]
- new REQUIRED verbIntsToIds(bigint[]) batch reverse resolver (L.7
identity-fingerprint design — verb ids are UUIDs by contract, so the
provider-side interning is losslessly reversible)
- addVerb(verb, sourceInt, targetInt) returns the interned verb int;
removeVerb(verbId) joins the contract
Coordinator (brainy.ts) owns ALL UUID <-> int conversion: getOrAssign on
writes, getInt on reads (unmapped UUID -> empty result without calling the
provider), getUuid / verbIntsToIds on returns, plus a bounded ~100k-entry
insertion-order warm cache for verb-int -> verb-id pairs fed by addVerb
returns and resolver results. GraphVerb gains derived sourceInt/targetInt
(populated at add time, never persisted). findConnectedSubtype gains a
native fast path that routes single-type single-subtype outgoing BFS
through the provider when available.
JS GraphAdjacencyIndex satisfies the contract while staying string/u32-keyed
internally: entity ints resolve through the shared entity-id mapper (threaded
in by the coordinator on init/fork/checkout), verb ints come from an
in-process append-only interning map re-derived from storage on
rebuild/cold-start. ColumnStoreProvider widens the same way: addEntity/
removeEntity take bigint, sortTopK/filteredSortTopK return bigint[].
relate() now rejects a caller-supplied id with a teaching error — verb ids
are brainy-generated UUIDs by contract in 8.0 (previously a passed id was
silently ignored). No Roaring64 provider-boundary decode site exists yet;
the JS-internal column store stays Roaring32 and the Treemap decoder lands
with the first consumer of provider-returned filter buffers.
Public brain API unchanged. 1413 tests green (+10 new BigInt contract tests).
Step 3 of the brainy 8.0 rename scaffolding. The class name now matches
its role: the JS HNSW implementation of the VectorIndexProvider contract.
Per planning § 2.3: this is NOT cosmetic — leaving HNSWIndex when the
public contract is VectorIndexProvider creates a confusing read at the
implementation layer.
CHANGES
Repo-wide mechanical rename: HNSWIndex → JsHnswVectorIndex across 52
references in src/ + 5 references in tests/ via sed. Class declaration,
imports, JSDoc, comments, and identifiers all updated.
src/index.ts
- Primary public export: JsHnswVectorIndex (the new name).
- Backwards-compat alias: `export const HNSWIndex = JsHnswVectorIndex`
with @deprecated note. Removed in the final 8.0 cleanup commit.
NO-OP scope
No behavioural change. The class is exactly the same; only the name
moved. Tests + build green.
VERIFICATION
- npx tsc --noEmit: clean
- npm test: 1468 / 1468 unit
Optimistic concurrency for multi-writer coordination — the read-then-CAS
lock pattern + idempotent-bootstrap singleton inserts. Lands the surface the
SDK scheduler asked for in BRAINY-EXPOSE-TRANSACTIONS, scoped to what ships
cleanly without painting the 8.0 transact() API into a corner.
A. PER-ENTITY _rev FIELD
- src/coreTypes.ts — HNSWNounWithMetadata gains optional `_rev?: number`;
STANDARD_ENTITY_FIELDS includes it so resolveEntityField routes correctly.
- src/types/brainy.types.ts — Entity<T> gains optional `_rev?: number`;
Result<T> mirrors it on the convenience flatten layer.
- src/brainy.ts add() — initializes `_rev: 1` in storageMetadata. New entities
always start at 1.
- src/brainy.ts update() — reads currentRev off the persisted metadata
(falls back to 1 for pre-7.31.0 entities with no _rev), writes
`_rev: currentRev + 1` into the updated metadata. Every successful update()
bumps by exactly 1.
- src/brainy.ts convertNounToEntity + convertMetadataToEntity — both pull
_rev out of the storage metadata and surface it at the top level of Entity.
Pre-7.31.0 entities (no _rev in storage) read as `_rev: 1` so consumers
see a consistent value.
- src/storage/baseStorage.ts — six destructure sites updated to pull _rev
out of the metadata bag so it doesn't leak into customMetadata. Noun-side
returns surface _rev; verb-side destructures correctly but doesn't expose
it on HNSWVerbWithMetadata (verb CAS is future work).
- src/brainy.ts createResult() — flattens entity._rev onto the Result for
backward compat with the existing convenience-field layer.
B. update({ ifRev }) OPTIMISTIC CONCURRENCY
- src/types/brainy.types.ts — UpdateParams<T> gains optional `ifRev?: number`.
- src/transaction/RevisionConflictError.ts (NEW) — carries `{ id, expected,
actual }`. Message names the recipe: refetch with brain.get() and retry
with the latest _rev. Subclass of Error.
- src/brainy.ts update() — when params.ifRev is provided, compares against
currentRev (the rev we just read) and throws RevisionConflictError on
mismatch before any storage write. Omitting ifRev keeps the prior
unconditional-update behavior; existing consumers see no change.
- src/transaction/index.ts — exports RevisionConflictError.
- src/index.ts — public export of RevisionConflictError.
C. add({ ifAbsent }) BY-ID IDEMPOTENT INSERT
- src/types/brainy.types.ts — AddParams<T> gains optional `ifAbsent?: boolean`;
AddManyParams<T> mirrors it as a batch-level flag.
- src/brainy.ts add() — when params.id AND params.ifAbsent, pre-reads
storage.getNounMetadata(id); if present, returns the existing id without
writing. No throw, no overwrite. Ignored when id is omitted (a fresh UUID
can never collide).
- src/brainy.ts addMany() — propagates the batch-level ifAbsent to each
item's add() call. Per-item ifAbsent takes precedence so callers can
override individual rows.
WHAT'S NOT SHIPPED (and why)
A public brain.transaction(fn) wrapper was on the table but was cut. The
internal TransactionManager exposes raw Operation classes (SaveNounMetadata,
etc.) that take StorageAdapter as a constructor argument. A clean high-level
facade in 7.31.0 would have meant either:
(a) Delegate to brain.add() / update() / relate(). Each of those opens its
own internal transaction and commits before the closure returns. Looks
atomic, isn't — a footgun.
(b) Thread an optional `tx?` through every internal write site in
brainy.ts (8 transactionManager.executeTransaction sites). ~2 days of
real refactor with regression surface, and the API shape changes again
in 8.0 anyway.
The SDK scheduler's actual ask (BRAINY-EXPOSE-TRANSACTIONS) is the
read-then-CAS lock pattern. _rev + ifRev solves it completely. Multi-write
atomicity is the 8.0 brain.transact() use case where the Datomic-style
immutable Db makes it atomic by construction — that's the right home.
TESTS
- New tests/integration/rev-and-ifabsent.test.ts (18 tests):
- _rev initialization (1 on add) and surface on get fast/full paths + find
- _rev auto-bump on update across multiple writes
- update({ ifRev }) pass / fail / message format / omitted / legacy-no-rev
- add({ ifAbsent }) writes when absent / no-op when present / id-required
- addMany({ ifAbsent }) propagation + per-item override
- SDK-scheduler scenario: two concurrent CAS updates, one wins one throws
- Unit suite unchanged: 1468/1468.
- All integration subtype + verb + strict + find-limits + new rev suites
pass: 96/96.
DOCS
- New docs/guides/optimistic-concurrency.md (public: true) — full reference:
the lock pattern, read-modify-write retry, idempotent bootstrap, how _rev
interacts with brain.versions, branches/fork, and VFS, what's coming in 8.0.
- docs/api/README.md — add() and update() entries get the new params + tips
pointing at the new guide.
- RELEASES.md v7.31.0 entry.
CORTEX COMPATIBILITY
Zero changes required. _rev is a metadata column already supported by
NativeColumnStore. The auto-bump runs in Brainy JS before any storage call;
Cortex never sees the per-entity counter.
8.0 FORWARD-COMPAT
_rev, ifRev, RevisionConflictError, and ifAbsent survive the 8.0 Db redesign
unchanged. 8.0 layers brain.transact(tx, { ifAtGeneration }) for whole-tx CAS
on top of the same per-entity mechanism — per-entity for single-record
patterns (job locks, idempotent state machines), generation-based for
"did the world move under me." Locked in .strategy/BRAINY-8.0-SUBTYPE-CONTRACT.md § C-6.
Verification
- npx tsc --noEmit: clean
- npm test: 1468 / 1468 unit
- All integration suites including new rev-and-ifabsent: 96/96
- npm run build: clean
- Closed-source product reference audit: clean
Shutdown/close/flush now properly flushes all 4 components in parallel:
metadataIndex, graphIndex, HNSW dirty nodes, and storage counts. Previously
only counts were flushed, causing native provider data loss on restart.
Also:
- Wire roaring, msgpack, entityIdMapper provider consumption from plugins
- Fix allOf filter O(n²) intersection → O(n) Set-based
- Fix ne/exists negation filter to use Set-based exclusion
- Add setMsgpackImplementation() swap in SSTable for native msgpack
- Add setRoaringImplementation() swap for native CRoaring bitmaps
- Add getAllIntIds() to EntityIdMapper for bitmap operations
- Remove TypeAwareHNSWIndex from default index creation path
- Export memory detection utilities from internals
- Clean up 26 permanently-skipped dead tests
- Remove detectAndRepairCorruption from init() hot path — was loading all
metadata chunks sequentially on startup. Now available via checkHealth()
and repairIndex() methods.
- Short-circuit warmCache on empty workspace — skip 4-6 wasted storage reads.
- Parallelize MetadataIndex.init() and getGraphIndex() via Promise.all().
- Defer metadata writes during rebuild to batch boundaries (every 5000
entities) instead of flushing per-entity.
- Skip pre-reads for new entities in transactions — saves 2 storage
round-trips per add() on cloud storage.
