Three additive surfaces for native index providers, which hold only
`storage` and must never construct their own fact-log reader (the log's
open path is writer-side — it reconciles by truncating/rewriting):
- Fact-scan capability on the storage adapter (the getBinaryBlobPath
pattern): the host brain wires a closure over its LIVE fact log at
init; providers call storage.scanFacts()/factLogHeadGeneration()/
factSegmentPaths() and fall back to the enumeration walk on null.
Restore/reopen swaps the underlying log transparently.
- The family-stamp trio (readFamilyStamp/writeFamilyStamp/
verifyFamilyStamp + types) exported from @soulcraft/brainy/internals,
so 'one verifier' is literally one function shared with the native
side, never two synchronized copies.
- Rollup invariants widened to number|string: content fingerprints
(e.g. a per-tree SHA-256) are valid invariant values; strict equality
either way, and a type mismatch reads as incoherence, never a pass.
Every committed generation now also appends a FACT — an after-image
commit record (what each touched entity/relationship became, or a
body-less tombstone for a removal) — to an append-only, crc32c-framed
segment log under _generations/facts/. The before-image history and the
canonical tree remain authoritative; the fact log gives consumers ONE
sequential, self-verifying stream (index heals, incremental replays)
in place of a per-entity directory walk.
- Wire format: positional msgpack facts [generation, timestamp, ops,
meta, blobHashes]; op = [kind u8, id bin16, record | nil tombstone];
32-byte segment header (magic, formatVersion, firstGeneration,
zeroed+verified reserved); length+crc32c frame per fact; zero-padded
segment names so lexicographic order == generation order; JSON
manifest with an atomic rename flip, manifest-first rotation.
- Commit protocol: facts append+fsync BEFORE the commit point inside
the existing durability window, so a crash can only leave the log
AHEAD of committed truth — open() truncates back (torn tails detected
by CRC). Absent generation = never committed; a scan can never see an
uncommitted fact. transact() facts are durable-on-return; single-op
facts ride the group-commit flush exactly like buffered history. A
fact-append failure fails the write, loudly — a silent gap would be a
lie a later replay discovers.
- New public surface: brain.scanFacts() (sequential batches with heal
telemetry: head/segments/approx up front, per-batch generation range
+ bytes + segment id, loud abort on gaps, summary cross-check) and
brain.factSegmentPaths() (immutable sealed segments for zero-copy
consumers; the mutable tail excluded). Exported types CommitFact,
FactOp, FactScanBatch, FactScanHandle.
- Storage: optional binary raw-byte primitives (appendRawBytes,
readRawBytes, writeRawBytes, rawByteSize) on StorageAdapter —
feature-detected; filesystem + memory adapters implement them; an
adapter without them hosts no fact log. Fact segments are byte-copied
(never hard-linked) into snapshots. The _generations/facts/ namespace
is registered as a protected family (rebuildable: false): no sweeper
or GC may delete under it.
- New crc32c (Castagnoli) utility with RFC known-answer tests.
