diff --git a/src/brainy.ts b/src/brainy.ts index 8ba991dd..9ab3acee 100644 --- a/src/brainy.ts +++ b/src/brainy.ts @@ -8265,6 +8265,27 @@ export class Brainy implements BrainyInterface { return this.generationStore.compact(options) } + /** + * @description Repack cold generation history into sealed segments — + * re-representation, never deletion: every record and delta stays readable + * (`asOf()` unchanged); the physical file count drops by orders of + * magnitude. Runs automatically (time-bounded) at `close()`; call this for + * explicit maintenance windows on long-lived writers. The ONLY history + * transform permitted under the archival profile (`retention: 'all'`). + * @param options - `timeBudgetMs` bounds the pass (early stop = consistent + * prefix, next pass resumes); `batchGenerations` sizes each fold. + * @returns Folded generation count and segments created. + */ + async repackHistory(options?: { + timeBudgetMs?: number + batchGenerations?: number + }): Promise<{ foldedGenerations: number; segmentsCreated: number }> { + this.assertWritable('repackHistory') + await this.ensureInitialized() + await this.generationStore.flushPendingSingleOps() + return this.generationStore.repackHistory(options) + } + /** * @description Read-only generational-history footprint for fleet audits: * generation count, total on-disk bytes, generation/timestamp range, the @@ -8292,6 +8313,24 @@ export class Brainy implements BrainyInterface { } } + /** + * @description A deterministic content digest of the generation log through + * `g` (D8 — gate-to-generation provenance): identical history produces the + * identical digest on any machine; divergence produces a different one. + * Release gates and suite verdicts pin `{generation, digest}` and verify + * both at execution time instead of pinning a git commit. O(segments + + * live-tier window), never O(all generations). Throws `RangeError` out of + * range and `GenerationCompactedError` below the horizon — a gate can + * never silently pin reclaimed history. + * @example + * const gate = { generation: brain.generation(), digest: await brain.generationDigest(brain.generation()) } + */ + async generationDigest(g: number): Promise { + await this.ensureInitialized() + await this.generationStore.flushPendingSingleOps() + return this.generationStore.generationDigest(g) + } + /** * @description Drive the adaptive retention byte budget at runtime — the * settable input a machine-level coordinator (e.g. cor's `ResourceManager`, @@ -16192,11 +16231,21 @@ export class Brainy implements BrainyInterface { await this.generationStore.flushPendingSingleOps() } - // Phase 0b: Auto-compact generational history per config.retention (default - // on) BEFORE the generation store closes below. This is THE auto-compaction - // site (8.9.0 — flush() never compacts): time-bounded per pass, respects - // live Db pins and an explicit autoCompact: false; no-op on read-only - // instances. + // Phase 0b: REPACK cold history into sealed segments (D1+D3 — + // re-representation, never deletion; the only history transform under the + // archival profile), then auto-compact per config.retention. Repack runs + // FIRST so bounded-retention reclaim can drop whole segments. Both are + // time-bounded maintenance passes (8.9.0 law: flush() never pays these); + // both are housekeeping — failures warn, never fail a clean shutdown. + if (!this.isReadOnly && this.generationStore) { + try { + await this.generationStore.repackHistory({ timeBudgetMs: 5_000 }) + } catch (error) { + console.warn( + `History repacking failed (non-fatal): ${error instanceof Error ? error.message : String(error)}` + ) + } + } await this.autoCompactHistory() // Phase 1: Flush ALL components in parallel to persist buffered data diff --git a/src/db/factLog.ts b/src/db/factLog.ts index 4c5e95fd..94e79700 100644 --- a/src/db/factLog.ts +++ b/src/db/factLog.ts @@ -102,12 +102,26 @@ export interface FactScanBatch { segmentId: string } +/** + * Liveness bound on a scan's FIRST batch (Stage-2 co-freeze, D1 contract): + * `batches()` must yield its first batch — or fail loudly — within this many + * ms of the first pull. A backlogged or damaged store may be SLOW, but it may + * never be SILENT: a consumer awaiting the first batch is otherwise + * indistinguishable from a wedge (the exact failure shape a production heal + * hit against a generations-backlogged brain). + */ +export const SCANFACTS_FIRST_BATCH_MS = 10_000 + /** The telemetry a scan OPEN returns (frozen shape). */ export interface FactScanHandle { headGeneration: number segmentCount: number approxFactCount: number - /** Ordered batches; a detected gap aborts LOUDLY, never a silent skip. */ + /** + * Ordered batches; a detected gap aborts LOUDLY, never a silent skip. + * Liveness contract: the FIRST batch resolves or rejects within + * {@link SCANFACTS_FIRST_BATCH_MS} of the first pull — never a silent hang. + */ batches: () => AsyncGenerator /** Close telemetry — the invariant cross-check, valid after iteration ends. */ summary: () => { factsYielded: number; segmentsRead: number } @@ -440,6 +454,8 @@ export class FactLog { toGeneration?: number kinds?: Array<'noun' | 'verb'> batchSize?: number + /** Test override for the first-batch liveness bound (default {@link SCANFACTS_FIRST_BATCH_MS}). */ + firstBatchTimeoutMs?: number }): FactScanHandle { const from = options?.fromGeneration ?? 1 const to = options?.toGeneration ?? this.head @@ -514,11 +530,43 @@ export class FactLog { } } + // Liveness wrapper: the FIRST pull races the contract deadline. Only the + // first — the bound is time-to-first-batch (proof the producer is alive), + // not per-batch pacing; and it runs only while a pull is actually pending, + // so consumer think-time between pulls never counts against the producer. + const firstBatchTimeoutMs = options?.firstBatchTimeoutMs ?? SCANFACTS_FIRST_BATCH_MS + async function* batchesWithLiveness(this: void): AsyncGenerator { + const inner = batches() + let timer: NodeJS.Timeout | undefined + try { + const deadline = new Promise((_, reject) => { + timer = setTimeout( + () => + reject( + new Error( + `fact log: scanFacts produced no first batch within ${firstBatchTimeoutMs}ms ` + + `(liveness contract) — the store is wedged or unreadably slow; aborting scan LOUDLY ` + + `instead of hanging the consumer.` + ) + ), + firstBatchTimeoutMs + ) + timer.unref?.() + }) + const first = await Promise.race([inner.next(), deadline]) + if (first.done) return + yield first.value + } finally { + clearTimeout(timer) + } + yield* inner + } + return { headGeneration: this.head, segmentCount: segments.length + (tailSnapshot.length > 0 ? 1 : 0), approxFactCount, - batches, + batches: batchesWithLiveness, summary: () => ({ factsYielded, segmentsRead }) } } diff --git a/src/db/generationSegments.ts b/src/db/generationSegments.ts new file mode 100644 index 00000000..0c14b60c --- /dev/null +++ b/src/db/generationSegments.ts @@ -0,0 +1,459 @@ +/** + * @module db/generationSegments + * @description The generation-segment store — Stage-2 D1+D3+repacking's file + * format (co-frozen 2026-07-19; design: the d1-d3-repacking spec). + * + * Packs CONSECUTIVE cold generations' record-sets (before-images + delta) + * into append-once segment files with derived sidecar indexes, so history + * scales in SEGMENTS (tens) instead of FILES-PER-GENERATION (hundreds of + * thousands), and cold-open reads ONE manifest instead of listing the + * backlog. Layout under `_generations/segments/`: + * + * - `seg-.bgs` — magic "BGS1", then one frame per + * generation: `u32 payloadLen | u32 crc32c | msgpack payload`. Payload is + * POSITIONAL: `[generation, timestamp, delta, records[], flags]` with + * records `[kindByte, id, record]`. `flags` reserves encoding evolution + * (bit 0 = compressed payload — v1 always 0; a future writer upgrade, + * never a format break). Sealed segments are IMMUTABLE — the fact log's + * own law, generalized. + * - `seg-.idx` — DERIVED sidecar (msgpack): per-generation frame + * offsets (point reads = one ranged read, never a listing) + per-id + * generation postings (per-id chain rebuilds read only what they need). + * Corrupt/missing → rebuilt from its segment in one sequential read, + * loudly. + * - `manifest.json` — the segment catalogue + `compactedBelow` (D3's + * horizon marker). Cold-open reads THIS; the packed backlog is never + * listed. + * + * D3 semantics carried here: bounded-retention reclaim drops WHOLE segments + * at boundaries (O(1) per segment, no rewrite); under the archival profile + * (`retention: 'all'`) nothing here is ever dropped — folding is the only + * transform (re-representation, never deletion). + */ + +import { encode as msgpackEncode, decode as msgpackDecode } from '@msgpack/msgpack' +import { crc32c } from '../utils/crc32c.js' +import type { FactLogStorage } from './factLog.js' +import { prodLog } from '../utils/logger.js' + +/** Directory for segment files + manifest, under the generations prefix. */ +export const SEGMENTS_PREFIX = '_generations/segments' + +/** Target sealed-segment size (co-freeze proposal; tunable on evidence). */ +export const SEGMENT_TARGET_BYTES = 64 * 1024 * 1024 + +const MAGIC = new TextEncoder().encode('BGS1') +const FRAME_PREFIX_BYTES = 8 // u32 payloadLen + u32 crc32c +const MANIFEST_PATH = `${SEGMENTS_PREFIX}/manifest.json` + +/** One generation's fold input — exactly what the live tier holds for it. */ +export interface FoldGeneration { + generation: number + timestamp: number + /** The tx.json delta object, carried verbatim. */ + delta: unknown + /** The before-image record-set (empty for record-less generations). */ + records: Array<{ kind: 'noun' | 'verb'; id: string; record: unknown }> +} + +/** Manifest entry for one sealed segment. */ +export interface SegmentMeta { + file: string + firstGeneration: number + lastGeneration: number + frames: number + bytes: number + /** crc32c of the full segment byte stream — the digest chain's link. */ + checksum: number +} + +interface SegmentManifest { + version: 1 + compactedBelow: number + segments: SegmentMeta[] +} + +interface SidecarIndex { + version: 1 + /** [generation, frameOffset, frameLen] ascending by generation. */ + generations: Array<[number, number, number]> + /** `${kindByte}:${id}` → ascending generations holding a record for it. */ + ids: Record +} + +const segmentFileName = (firstGeneration: number): string => + `seg-${String(firstGeneration).padStart(20, '0')}.bgs` +const sidecarFileName = (firstGeneration: number): string => + `seg-${String(firstGeneration).padStart(20, '0')}.idx` + +/** + * The generation-segment store. Owns the packed tier ONLY — the live + * per-generation tier and the routing between tiers belong to + * `GenerationStore`. All mutating entry points here are called under the + * generation store's commit mutex. + */ +export class GenerationSegmentStore { + private readonly storage: FactLogStorage + private manifest: SegmentManifest = { version: 1, compactedBelow: 0, segments: [] } + /** Sidecar cache — segments are immutable, so entries never invalidate. */ + private readonly sidecars = new Map() + + constructor(storage: FactLogStorage) { + this.storage = storage + } + + /** Load the manifest (ONE read — never a directory listing). */ + async open(): Promise { + const raw = (await this.storage.readRawObject(MANIFEST_PATH)) as SegmentManifest | null + if (raw) { + if (raw.version !== 1) { + throw new Error( + `[GenerationSegments] manifest version ${String(raw.version)} is newer than this ` + + `engine understands — refusing to serve partial history. Upgrade the engine.` + ) + } + this.manifest = raw + } + } + + /** The packed tier's catalogue (ascending, immutable snapshot). */ + segments(): readonly SegmentMeta[] { + return this.manifest.segments + } + + /** D3's horizon marker: generations below this were reclaimed (bounded profiles only). */ + compactedBelow(): number { + return this.manifest.compactedBelow + } + + /** The covering sealed segment for `gen`, or null if it lives outside the packed tier. */ + private coveringSegment(gen: number): SegmentMeta | null { + // Manifest is ascending and ranges never overlap — binary search. + const segs = this.manifest.segments + let lo = 0 + let hi = segs.length - 1 + while (lo <= hi) { + const mid = (lo + hi) >> 1 + const s = segs[mid] + if (gen < s.firstGeneration) hi = mid - 1 + else if (gen > s.lastGeneration) lo = mid + 1 + else return s + } + return null + } + + /** True when `gen` is packed (readable from this tier). */ + hasGeneration(gen: number): boolean { + return this.coveringSegment(gen) !== null + } + + /** + * Fold consecutive generations into ONE new sealed segment + sidecar and + * append it to the manifest atomically. Caller guarantees: `gens` is + * ascending, contiguous with the packed tier (first = last packed + 1 when + * segments exist), and already durable in the live tier. Crash between the + * segment write and the caller's live-tier delete leaves a DUPLICATE + * representation — resolved live-tier-wins by the reader; never a gap. + */ + async fold(gens: FoldGeneration[]): Promise { + if (gens.length === 0) { + throw new Error('[GenerationSegments] fold() requires at least one generation') + } + for (let i = 1; i < gens.length; i++) { + if (gens[i].generation <= gens[i - 1].generation) { + throw new Error('[GenerationSegments] fold() input must be strictly ascending') + } + } + const last = this.manifest.segments[this.manifest.segments.length - 1] + if (last && gens[0].generation <= last.lastGeneration) { + throw new Error( + `[GenerationSegments] fold() overlaps the packed tier: ${gens[0].generation} ≤ ` + + `sealed ${last.lastGeneration} — segments are immutable, never rewritten` + ) + } + + const first = gens[0].generation + const file = segmentFileName(first) + const sidecar: SidecarIndex = { version: 1, generations: [], ids: {} } + + // Encode all frames, tracking offsets for the sidecar. + const parts: Uint8Array[] = [MAGIC] + let offset = MAGIC.length + for (const g of gens) { + const payload = msgpackEncode([ + g.generation, + g.timestamp, + g.delta, + g.records.map((r) => [r.kind === 'noun' ? 0 : 1, r.id, r.record]), + 0 // flags: v1 = uncompressed + ]) + const frame = new Uint8Array(FRAME_PREFIX_BYTES + payload.length) + const view = new DataView(frame.buffer) + view.setUint32(0, payload.length, true) + view.setUint32(4, crc32c(payload), true) + frame.set(payload, FRAME_PREFIX_BYTES) + sidecar.generations.push([g.generation, offset, frame.length]) + for (const r of g.records) { + const key = `${r.kind === 'noun' ? 0 : 1}:${r.id}` + ;(sidecar.ids[key] ??= []).push(g.generation) + } + parts.push(frame) + offset += frame.length + } + const total = parts.reduce((n, p) => n + p.length, 0) + const bytes = new Uint8Array(total) + let at = 0 + for (const p of parts) { + bytes.set(p, at) + at += p.length + } + + const meta: SegmentMeta = { + file, + firstGeneration: first, + lastGeneration: gens[gens.length - 1].generation, + frames: gens.length, + bytes: total, + checksum: crc32c(bytes) + } + + // Durability order: segment + sidecar fsync'd BEFORE the manifest names + // them (a crash before the manifest = invisible orphan files, harmless); + // manifest last, atomically. + const segPath = `${SEGMENTS_PREFIX}/${file}` + const idxPath = `${SEGMENTS_PREFIX}/${sidecarFileName(first)}` + await this.storage.writeRawBytes(segPath, bytes) + await this.storage.writeRawBytes(idxPath, msgpackEncode(sidecar)) + await this.storage.syncRawObjects([segPath, idxPath]) + const next: SegmentManifest = { + ...this.manifest, + segments: [...this.manifest.segments, meta] + } + await this.storage.writeRawObject(MANIFEST_PATH, next) + await this.storage.syncRawObjects([MANIFEST_PATH]) + this.manifest = next + this.sidecars.set(file, sidecar) + return meta + } + + /** Load (or rebuild, loudly) a segment's sidecar. */ + private async sidecarFor(meta: SegmentMeta): Promise { + const cached = this.sidecars.get(meta.file) + if (cached) return cached + const idxPath = `${SEGMENTS_PREFIX}/${sidecarFileName(meta.firstGeneration)}` + const raw = await this.storage.readRawBytes(idxPath) + if (raw) { + try { + const idx = msgpackDecode(raw) as SidecarIndex + if (idx.version === 1) { + this.sidecars.set(meta.file, idx) + return idx + } + } catch { + // fall through to rebuild + } + } + // Sidecars are DERIVED: rebuild from the segment, loudly — never serve + // wrong offsets silently. + prodLog.warn( + `[GenerationSegments] sidecar for ${meta.file} missing or unreadable — rebuilding from the segment` + ) + const rebuilt = await this.rebuildSidecar(meta) + await this.storage.writeRawBytes(idxPath, msgpackEncode(rebuilt)) + this.sidecars.set(meta.file, rebuilt) + return rebuilt + } + + /** One sequential read of the segment → a fresh sidecar. Verifies every frame CRC. */ + private async rebuildSidecar(meta: SegmentMeta): Promise { + const frames = await this.readAllFrames(meta) + const idx: SidecarIndex = { version: 1, generations: [], ids: {} } + for (const f of frames) { + idx.generations.push([f.generation, f.offset, f.frameLen]) + for (const r of f.records) { + const key = `${r.kind === 'noun' ? 0 : 1}:${r.id}` + ;(idx.ids[key] ??= []).push(f.generation) + } + } + return idx + } + + private decodeFrame( + payload: Uint8Array + ): { generation: number; timestamp: number; delta: unknown; records: FoldGeneration['records'] } { + const [generation, timestamp, delta, rawRecords] = msgpackDecode(payload) as [ + number, + number, + unknown, + Array<[number, string, unknown]>, + number + ] + return { + generation, + timestamp, + delta, + records: rawRecords.map(([kindByte, id, record]) => ({ + kind: kindByte === 0 ? ('noun' as const) : ('verb' as const), + id, + record + })) + } + } + + private async readAllFrames(meta: SegmentMeta): Promise< + Array & { offset: number; frameLen: number }> + > { + const bytes = await this.storage.readRawBytes(`${SEGMENTS_PREFIX}/${meta.file}`) + if (!bytes) { + throw new Error( + `[GenerationSegments] sealed segment ${meta.file} is MISSING — packed history is damaged; ` + + `refusing to continue silently` + ) + } + const out: Array & { offset: number; frameLen: number }> = [] + let at = MAGIC.length + const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength) + while (at + FRAME_PREFIX_BYTES <= bytes.length) { + const payloadLen = view.getUint32(at, true) + const crc = view.getUint32(at + 4, true) + const payload = bytes.subarray(at + FRAME_PREFIX_BYTES, at + FRAME_PREFIX_BYTES + payloadLen) + if (payload.length !== payloadLen || crc32c(payload) !== crc) { + throw new Error( + `[GenerationSegments] frame CRC mismatch in ${meta.file} at offset ${at} — ` + + `packed history is damaged; refusing to serve it` + ) + } + out.push({ ...this.decodeFrame(payload), offset: at, frameLen: FRAME_PREFIX_BYTES + payloadLen }) + at += FRAME_PREFIX_BYTES + payloadLen + } + return out + } + + /** Read one packed generation's frame via its sidecar offset (one ranged read). */ + private async readFrame( + gen: number + ): Promise | null> { + const meta = this.coveringSegment(gen) + if (!meta) return null + const idx = await this.sidecarFor(meta) + // generations ascending → binary search. + const gens = idx.generations + let lo = 0 + let hi = gens.length - 1 + while (lo <= hi) { + const mid = (lo + hi) >> 1 + if (gens[mid][0] < gen) lo = mid + 1 + else if (gens[mid][0] > gen) hi = mid - 1 + else { + const [, offset, frameLen] = gens[mid] + const bytes = await this.storage.readRawBytes(`${SEGMENTS_PREFIX}/${meta.file}`) + if (!bytes) { + throw new Error(`[GenerationSegments] sealed segment ${meta.file} is MISSING`) + } + const frame = bytes.subarray(offset, offset + frameLen) + const view = new DataView(frame.buffer, frame.byteOffset, frame.byteLength) + const payloadLen = view.getUint32(0, true) + const crc = view.getUint32(4, true) + const payload = frame.subarray(FRAME_PREFIX_BYTES, FRAME_PREFIX_BYTES + payloadLen) + if (payload.length !== payloadLen || crc32c(payload) !== crc) { + throw new Error( + `[GenerationSegments] frame CRC mismatch for generation ${gen} in ${meta.file} — ` + + `packed history is damaged; refusing to serve it` + ) + } + return this.decodeFrame(payload) + } + } + // In the covering range but not present: the packed tier is dense by + // construction (fold packs every generation it is handed, including + // record-less ones) — absence inside a sealed range is damage. + throw new Error( + `[GenerationSegments] generation ${gen} is inside sealed segment ${meta.file}'s declared ` + + `range but has no frame — packed history is damaged` + ) + } + + /** The packed tier's delta for `gen` (null = not packed). */ + async readDelta(gen: number): Promise<{ delta: unknown; timestamp: number } | null> { + const frame = await this.readFrame(gen) + return frame ? { delta: frame.delta, timestamp: frame.timestamp } : null + } + + /** The packed tier's full record-set for `gen` (null = not packed). */ + async readRecords(gen: number): Promise { + const frame = await this.readFrame(gen) + return frame ? frame.records : null + } + + /** One packed before-image (null = not packed OR no record for the id in that generation). */ + async readRecord(gen: number, kind: 'noun' | 'verb', id: string): Promise { + const frame = await this.readFrame(gen) + if (!frame) return null + const hit = frame.records.find((r) => r.kind === kind && r.id === id) + return hit ? hit.record : null + } + + /** + * D3 reclaim: drop WHOLE segments whose lastGeneration < `belowGeneration` + * and bump `compactedBelow`. Partial segments are never dropped — the + * boundary waits. NEVER called under the archival profile (the caller + * enforces retention semantics; this method only executes boundary drops). + */ + async dropSegmentsBelow(belowGeneration: number): Promise<{ dropped: number; compactedBelow: number }> { + const keep: SegmentMeta[] = [] + const drop: SegmentMeta[] = [] + for (const s of this.manifest.segments) { + ;(s.lastGeneration < belowGeneration ? drop : keep).push(s) + } + if (drop.length === 0) { + return { dropped: 0, compactedBelow: this.manifest.compactedBelow } + } + const compactedBelow = Math.max( + this.manifest.compactedBelow, + drop[drop.length - 1].lastGeneration + 1 + ) + // Manifest first (the drop is authoritative once named), then bytes — + // a crash between leaves orphan segment files invisible to the manifest, + // harmless and re-collectable. + const next: SegmentManifest = { ...this.manifest, compactedBelow, segments: keep } + await this.storage.writeRawObject(MANIFEST_PATH, next) + await this.storage.syncRawObjects([MANIFEST_PATH]) + this.manifest = next + for (const s of drop) { + await this.storage.deleteRawObject(`${SEGMENTS_PREFIX}/${s.file}`) + await this.storage.deleteRawObject(`${SEGMENTS_PREFIX}/${sidecarFileName(s.firstGeneration)}`) + this.sidecars.delete(s.file) + } + return { dropped: drop.length, compactedBelow } + } + + /** + * D8 rider — the packed portion of `generationDigest(g)`: a deterministic + * crc32c chain over sealed-segment checksums fully below `g`, plus the + * frame CRC of `g`'s own frame when `g` is mid-segment. O(segments), not + * O(generations); identical history ⇒ identical digest on any machine. + * The live-tier portion is composed by the caller. + */ + async digestThroughPacked(g: number): Promise { + let digest = 0 + let covered = false + for (const s of this.manifest.segments) { + if (s.lastGeneration <= g) { + digest = crc32c(new TextEncoder().encode(`${digest}:${s.checksum}`)) + if (s.lastGeneration === g) covered = true + } else if (s.firstGeneration <= g) { + // g is mid-segment: chain the partial prefix via g's frame CRC. + const frame = await this.readFrame(g) + if (frame === null) return null + const idx = await this.sidecarFor(s) + const upTo = idx.generations.filter(([gen]) => gen <= g) + for (const [gen, offset, frameLen] of upTo) { + digest = crc32c(new TextEncoder().encode(`${digest}:${gen}:${offset}:${frameLen}`)) + } + covered = true + break + } + } + return covered || this.manifest.segments.length > 0 ? digest : null + } +} diff --git a/src/db/generationStore.ts b/src/db/generationStore.ts index 4e3738d9..aede17a4 100644 --- a/src/db/generationStore.ts +++ b/src/db/generationStore.ts @@ -46,6 +46,8 @@ import type { TxLogEntry } from './types.js' import { FactLog, storageSupportsFactLog, type CommitFact, type FactOp } from './factLog.js' +import { GenerationSegmentStore, type FoldGeneration } from './generationSegments.js' +import { crc32c } from '../utils/crc32c.js' /** * The byte-identical before-images of every id a commit touches, read UNDER @@ -266,6 +268,21 @@ export class GenerationStore { */ private historyBytesTotal: number | null = null + /** + * The packed tier (D1+D3): sealed segments holding folded cold + * generations. Null until {@link open} wires it (and on storage adapters + * without raw-byte primitives — the live tier then carries everything, + * exactly as before the packed tier existed). + */ + private segments: GenerationSegmentStore | null = null + + /** + * Live-tier window: generations newer than `committed - REPACK_LIVE_WINDOW` + * are never folded — the hot tail stays in the per-generation layout the + * write path owns. Matches the resident chain window's scale. + */ + static readonly REPACK_LIVE_WINDOW = 1024 + /** * Model-B per-write group-commit — the in-memory PENDING tier. * @@ -433,6 +450,33 @@ export class GenerationStore { this.factLog = null } + // PACKED TIER (D1+D3): same capability gate as the fact log. Opening + // reads ONE manifest — never a listing of the packed backlog — and seeds + // committedRanges with the sealed ranges so packed generations resolve + // exactly like live ones. + if (storageSupportsFactLog(this.storage)) { + this.segments = new GenerationSegmentStore(this.storage) + await this.segments.open() + const packedRanges = this.segments + .segments() + .map((s): [number, number] => [s.firstGeneration, Math.min(s.lastGeneration, this.committed)]) + .filter(([lo, hi]) => lo <= hi) + if (packedRanges.length > 0) { + // Merge packed (older) + live (newer) interval sets — both ascending; + // coalesce adjacency so range arithmetic stays interval-exact. + const merged: Array<[number, number]> = [] + for (const r of [...packedRanges, ...this.committedRanges].sort((a, b) => a[0] - b[0])) { + const last = merged[merged.length - 1] + if (last && r[0] <= last[1] + 1) last[1] = Math.max(last[1], r[1]) + else merged.push([r[0], r[1]]) + } + this.committedRanges = merged + } + this.horizonGen = Math.max(this.horizonGen, this.segments.compactedBelow() - 1) + } else { + this.segments = null + } + // Hook single-op write batches so generation() is always meaningful. // Suppressed while a transact batch executes (the batch is ONE generation). if (!options?.readOnly) { @@ -500,6 +544,51 @@ export class GenerationStore { * deltas (cache-bounded reads). * @returns Counts, bytes, generation range, and the compaction horizon. */ + /** + * @description D8 (gate-to-generation provenance): a deterministic content + * digest of the generation log THROUGH `g` — identical history ⇒ identical + * digest on any machine; any divergence (different records, different + * order, reclaimed range) ⇒ different digest. Composed from the packed + * tier's sealed-segment checksum chain (O(segments)) plus the live tier's + * per-generation delta digests (O(live window at most)). Release gates pin + * {generation, digest} and verify both at execution time. + * @param g - The generation to digest through (≤ committed). + * @returns A hex digest string, stable across reopen and repacking states + * ONLY for fully-packed prefixes — repacking changes representation, so + * the composed digest is defined over CONTENT: live-tier gens hash their + * delta + record ids, packed gens hash via frame CRCs. A gate should pin + * after a repack pass for long-term stability, or re-pin on repack. + */ + async generationDigest(g: number): Promise { + if (!Number.isInteger(g) || g < 1 || g > this.committed) { + throw new RangeError( + `generationDigest(): generation ${g} is out of range [1, ${this.committed}]` + ) + } + if (g <= this.horizonGen) { + throw new GenerationCompactedError(g, this.horizonGen) + } + let digest = 0 + const enc = new TextEncoder() + if (this.segments) { + const packed = await this.segments.digestThroughPacked(g) + if (packed !== null) digest = packed + } + // Live-tier composition: every committed gen ≤ g not covered by a sealed + // segment hashes its delta content in ascending order. + for (const gen of this.committedGensAsc()) { + if (gen > g) break + if (this.segments?.hasGeneration(gen)) continue + const delta = await this.getDelta(gen) + digest = crc32c( + enc.encode( + `${digest}:${gen}:${delta.timestamp}:${[...delta.nouns].sort().join(',')}:${[...delta.verbs].sort().join(',')}` + ) + ) + } + return digest.toString(16).padStart(8, '0') + } + async historyStats(): Promise<{ generations: number bytes: number @@ -538,14 +627,17 @@ export class GenerationStore { try { paths = await this.storage.listRawObjects(`${GENERATIONS_PREFIX}/${gen}/prev`) } catch { - return [] + paths = [] } const records: GenerationRecord[] = [] for (const p of paths) { const record = (await this.storage.readRawObject(p)) as GenerationRecord | null if (record) records.push(record) } - return records + if (records.length > 0) return records + // Two-tier: folded generations serve their record-set from the segment. + const packed = await this.segments?.readRecords(gen) + return packed ? (packed.map((r) => r.record) as GenerationRecord[]) : [] } /** @@ -1783,9 +1875,15 @@ export class GenerationStore { if (pending) { return (kind === 'noun' ? pending.nouns : pending.verbs).get(id) ?? null } - return (await this.storage.readRawObject( + const live = (await this.storage.readRawObject( `${GENERATIONS_PREFIX}/${gen}/prev/${id}.json` )) as GenerationRecord | null + if (live) return live + // Two-tier: the packed tier serves folded generations (live-tier-wins). + if (this.segments?.hasGeneration(gen)) { + return (await this.segments.readRecord(gen, kind, id)) as GenerationRecord | null + } + return null } /** @@ -2132,6 +2230,21 @@ export class GenerationStore { `${GENERATIONS_PREFIX}/${gen}/tx.json` )) as GenerationDelta | null if (delta === null) { + // Two-tier read (D1+D3): not in the live tier → the packed tier. + // Live-tier-wins ordering (a crash mid-fold leaves a duplicate, never + // a gap), so the segment lookup runs only after the live miss. + const packed = await this.segments?.readDelta(gen) + if (packed) { + const d = packed.delta as GenerationDelta + const entry = { + nouns: new Set(d.nouns), + verbs: new Set(d.verbs), + timestamp: packed.timestamp, + bytes: d.bytes ?? 0 + } + this.setDelta(gen, entry) + return entry + } throw new Error( `Generation delta missing: ${GENERATIONS_PREFIX}/${gen}/tx.json ` + `(store corrupted or records removed outside compactHistory())` @@ -2213,6 +2326,94 @@ export class GenerationStore { * @param options - Retention caps (see {@link CompactHistoryOptions}). * @returns Count of removed record-sets and the new horizon. */ + /** + * @description The REPACKER (D1+D3+repacking): fold cold live-tier + * generations into sealed segments — re-representation, never deletion. + * Every record and delta stays readable (asOf/chains unchanged); the + * per-generation directories are deleted only AFTER their segment is + * durable (crash between = duplicate representation, resolved + * live-tier-wins by every reader; never a gap). This is the transform that + * takes a 70k-file history to tens of segment files, and the ONLY history + * transform permitted under the archival profile. + * + * Folds oldest-first, contiguous from the packed boundary, in batches, and + * stops at the live window ({@link GenerationStore.REPACK_LIVE_WINDOW}) + * or when `timeBudgetMs` is spent — an early stop is a consistent prefix; + * the next pass resumes. + */ + async repackHistory(options?: { timeBudgetMs?: number; batchGenerations?: number }): Promise<{ + foldedGenerations: number + segmentsCreated: number + }> { + if (!this.segments) return { foldedGenerations: 0, segmentsCreated: 0 } + const segments = this.segments + return this.withMutex(async () => { + const deadline = + options?.timeBudgetMs !== undefined ? Date.now() + options.timeBudgetMs : undefined + const batchSize = options?.batchGenerations ?? 512 + const coldCeiling = this.committed - GenerationStore.REPACK_LIVE_WINDOW + const packedThrough = + segments.segments().length > 0 + ? segments.segments()[segments.segments().length - 1].lastGeneration + : 0 + + // Cold, unpacked, committed generations — ascending, contiguous scan. + const eligible: number[] = [] + for (const gen of this.committedGensAsc()) { + if (gen > coldCeiling) break + if (gen <= packedThrough) continue // already packed (dup fold barred) + if (this.pendingBuffer.has(gen)) continue // un-flushed = live by definition + eligible.push(gen) + } + + let folded = 0 + let segmentsCreated = 0 + for (let i = 0; i < eligible.length; i += batchSize) { + if (deadline !== undefined && Date.now() >= deadline) break + const batch = eligible.slice(i, i + batchSize) + const foldInput: FoldGeneration[] = [] + for (const gen of batch) { + const delta = (await this.storage.readRawObject( + `${GENERATIONS_PREFIX}/${gen}/tx.json` + )) as GenerationDelta | null + if (delta === null) { + // Already folded by a prior crashed pass whose dirs were removed, + // or damage — getDelta's two-tier read decides which, loudly, + // when someone asks. Skip; never fold a generation we cannot read. + continue + } + const records: FoldGeneration['records'] = [] + for (const [kind, ids] of [ + ['noun', delta.nouns] as const, + ['verb', delta.verbs] as const + ]) { + for (const id of ids) { + const record = await this.storage.readRawObject( + `${GENERATIONS_PREFIX}/${gen}/prev/${id}.json` + ) + if (record) records.push({ kind, id, record }) + } + } + foldInput.push({ generation: gen, timestamp: delta.timestamp, delta, records }) + } + if (foldInput.length === 0) continue + await segments.fold(foldInput) + segmentsCreated++ + // Segment + manifest durable → the live copies retire. + for (const g of foldInput) { + await this.storage.removeRawPrefix(`${GENERATIONS_PREFIX}/${g.generation}`) + } + folded += foldInput.length + } + if (folded > 0) { + prodLog.info( + `[GenerationStore] repacked ${folded} cold generation(s) into ${segmentsCreated} segment(s) — history preserved, file count reduced` + ) + } + return { foldedGenerations: folded, segmentsCreated } + }) + } + async compact(options?: CompactHistoryOptions): Promise { return this.withMutex(async () => { const minPinned = this.minPinnedGeneration() @@ -2304,6 +2505,16 @@ export class GenerationStore { // Reclaimed generations leave the per-id chains stale → rebuild on next read. this.invalidateChains() this.horizonGen = Math.max(this.horizonGen, highestRemoved) + // Packed-tier reclaim (D3): a packed generation's bytes live in a + // sealed segment — removeRawPrefix above was a no-op for it. Drop + // WHOLE segments now fully below the horizon; a partially-reclaimed + // segment keeps its bytes until the boundary passes it (the frozen + // partial-segments-wait rule; logical reclamation above still holds — + // the generations left committedRanges and asOf below the horizon + // throws regardless). + if (this.segments) { + await this.segments.dropSegmentsBelow(this.horizonGen + 1) + } const manifest: GenerationManifest = { version: 1, generation: this.committed, diff --git a/src/index.ts b/src/index.ts index ee01d885..b978b9fd 100644 --- a/src/index.ts +++ b/src/index.ts @@ -213,6 +213,7 @@ export type { CommitFact, FactOp, FactScanBatch, + SCANFACTS_FIRST_BATCH_MS, FactScanHandle } from './db/factLog.js' // The generalized family stamp — which source generation a projection diff --git a/src/storage/adapters/memoryStorage.ts b/src/storage/adapters/memoryStorage.ts index bab9d4d9..1b1f412e 100644 --- a/src/storage/adapters/memoryStorage.ts +++ b/src/storage/adapters/memoryStorage.ts @@ -133,6 +133,11 @@ export class MemoryStorage extends BaseStorage { */ protected async deleteObjectFromPath(path: string): Promise { this.objectStore.delete(path) + // Filesystem parity: on disk, objects and raw BYTE files are both just + // files — unlink removes whichever exists. Without this, deleteRawObject + // on a raw-bytes path (fact-log/generation segments) silently no-ops on + // memory storage: the delete "succeeds" and the bytes remain. + this.rawBytesStore.delete(path) } /** diff --git a/tests/integration/history-repacking.test.ts b/tests/integration/history-repacking.test.ts new file mode 100644 index 00000000..2bcee038 --- /dev/null +++ b/tests/integration/history-repacking.test.ts @@ -0,0 +1,186 @@ +/** + * @module tests/integration/history-repacking + * @description The D1+D3 two-tier history lifecycle end-to-end on a real + * brain. Laws: (1) repacking is RE-REPRESENTATION — after folding, every + * asOf() read below the fold boundary answers exactly as before, across a + * cold reopen; (2) folded per-generation directories are physically gone + * (the file-count cure is real, not cosmetic); (3) repack + reclaim compose: + * bounded retention after repacking drops whole segments and asOf below the + * horizon throws GenerationCompactedError; (4) repackHistory is explicit + * API and time-bounded (spent budget = consistent no-op). + * + * Uses a tiny REPACK_LIVE_WINDOW override so a small history has a cold + * tier at all (the production window is 1024). + */ +import { describe, it, expect, afterEach } from 'vitest' +import * as fs from 'node:fs' +import * as path from 'node:path' +import * as os from 'node:os' +import { Brainy } from '../../src/brainy.js' +import { NounType } from '../../src/types/graphTypes.js' +import { GenerationStore } from '../../src/db/generationStore.js' +import { GenerationCompactedError } from '../../src/db/errors.js' +import { SEGMENTS_PREFIX } from '../../src/db/generationSegments.js' + +const stub = async (text: string): Promise => { + const h = text.split('').reduce((a, c) => a + c.charCodeAt(0), 0) + return new Array(384).fill(0).map((_, i) => Math.sin(h + i)) +} + +const openBrain = async (dir: string): Promise => { + const brain = new Brainy({ + requireSubtype: false, + storage: { type: 'filesystem', path: dir }, + embeddingFunction: stub + }) + await brain.init() + return brain +} + +describe('history repacking — the two-tier lifecycle', () => { + const dirs: string[] = [] + const tempDir = (): string => { + const d = fs.mkdtempSync(path.join(os.tmpdir(), 'brainy-repack-')) + dirs.push(d) + return d + } + const originalWindow = GenerationStore.REPACK_LIVE_WINDOW + + afterEach(() => { + ;(GenerationStore as any).REPACK_LIVE_WINDOW = originalWindow + for (const d of dirs.splice(0)) { + try { + fs.rmSync(d, { recursive: true, force: true }) + } catch { + /* best effort */ + } + } + }) + + it('repack preserves every historical read across cold reopen; folded dirs are gone', async () => { + ;(GenerationStore as any).REPACK_LIVE_WINDOW = 3 + const dir = tempDir() + const brain = await openBrain(dir) + + const id = await brain.add({ + data: 'versioned-entity', + type: NounType.Document, + metadata: { v: 0 } + }) + for (let v = 1; v <= 10; v++) await brain.update({ id, metadata: { v } }) + await brain.flush() + + // Ground truth BEFORE repacking: capture asOf views for early generations. + const before: Record = {} + for (const g of [2, 4, 6]) { + const db = await brain.asOf(g) + before[g] = (await db.get(id))?.metadata?.v as number + await db.release() + } + + const result = await brain.repackHistory() + expect(result.foldedGenerations).toBeGreaterThan(0) + expect(result.segmentsCreated).toBeGreaterThan(0) + + // The folded per-generation directories are PHYSICALLY gone… + const genDirs = fs + .readdirSync(path.join(dir, '_generations'), { withFileTypes: true }) + .filter((e) => e.isDirectory() && /^\d+$/.test(e.name)).length + expect(genDirs).toBeLessThanOrEqual(4) // live window (3) + at most the newest + // …and the segment tier exists (the filesystem adapter stores objects + // gzipped, so the manifest may live at either spelling). + const segDir = path.join(dir, SEGMENTS_PREFIX) + expect( + fs.existsSync(path.join(segDir, 'manifest.json')) || + fs.existsSync(path.join(segDir, 'manifest.json.gz')) + ).toBe(true) + expect(fs.readdirSync(segDir).some((f) => f.endsWith('.bgs'))).toBe(true) + + // Same asOf answers from the packed tier, same process… + for (const g of [2, 4, 6]) { + const db = await brain.asOf(g) + expect((await db.get(id))?.metadata?.v).toBe(before[g]) + await db.release() + } + await brain.close() + + // …and across a COLD REOPEN (manifest discovery, no live dirs to list). + const reopened = await openBrain(dir) + for (const g of [2, 4, 6]) { + const db = await reopened.asOf(g) + expect((await db.get(id))?.metadata?.v).toBe(before[g]) + await db.release() + } + expect((await reopened.get(id))?.metadata?.v).toBe(10) // live state untouched + await reopened.close() + }) + + it('repack + bounded reclaim compose: whole segments drop, horizon is loud', async () => { + ;(GenerationStore as any).REPACK_LIVE_WINDOW = 2 + const dir = tempDir() + const brain = await openBrain(dir) + const id = await brain.add({ data: 'reclaim-probe', type: NounType.Document, metadata: { v: 0 } }) + for (let v = 1; v <= 8; v++) await brain.update({ id, metadata: { v } }) + await brain.flush() + await brain.repackHistory() + + // Reclaim down to the 3 newest generations — packed segments below the + // horizon drop whole; asOf below throws loudly. + const res = await brain.compactHistory({ maxGenerations: 3 }) + expect(res.removedGenerations).toBeGreaterThan(0) + await expect(brain.asOf(1)).rejects.toBeInstanceOf(GenerationCompactedError) + expect((await brain.get(id))?.metadata?.v).toBe(8) + await brain.close() + }) + + it('generationDigest: reopen-stable, divergence-sensitive, loud below the horizon', async () => { + ;(GenerationStore as any).REPACK_LIVE_WINDOW = 2 + const dir = tempDir() + const brain = await openBrain(dir) + const id = await brain.add({ data: 'digest-probe', type: NounType.Document, metadata: { v: 0 } }) + for (let v = 1; v <= 6; v++) await brain.update({ id, metadata: { v } }) + await brain.flush() + await brain.repackHistory() + + const gen = brain.generation() + const atHead = await brain.generationDigest(gen) + const atMid = await brain.generationDigest(3) + expect(atHead).toMatch(/^[0-9a-f]{8}$/) + expect(atMid).not.toBe(atHead) // more history ⇒ different digest + await brain.close() + + // Reopen-stable: same history, same digests (packed prefix stability). + const reopened = await openBrain(dir) + expect(await reopened.generationDigest(gen)).toBe(atHead) + expect(await reopened.generationDigest(3)).toBe(atMid) + + // New history diverges the head digest. + await reopened.update({ id, metadata: { v: 7 } }) + await reopened.flush() + expect(await reopened.generationDigest(reopened.generation())).not.toBe(atHead) + + // Below the horizon: LOUD, never a silent pin of reclaimed history. + await reopened.compactHistory({ maxGenerations: 2 }) + await expect(reopened.generationDigest(1)).rejects.toBeInstanceOf(GenerationCompactedError) + await reopened.close() + }) + + it('a spent time budget is a consistent no-op; the next pass resumes', async () => { + ;(GenerationStore as any).REPACK_LIVE_WINDOW = 2 + const dir = tempDir() + const brain = await openBrain(dir) + const id = await brain.add({ data: 'budget-probe', type: NounType.Document, metadata: { v: 0 } }) + for (let v = 1; v <= 6; v++) await brain.update({ id, metadata: { v } }) + await brain.flush() + + const bounded = await brain.repackHistory({ timeBudgetMs: 0 }) + expect(bounded).toEqual({ foldedGenerations: 0, segmentsCreated: 0 }) + + const resumed = await brain.repackHistory() + expect(resumed.foldedGenerations).toBeGreaterThan(0) + const db = await brain.asOf(3) + expect((await db.get(id))?.metadata?.v).toBeDefined() + await db.release() + await brain.close() + }) +}) diff --git a/tests/unit/db/fact-log.test.ts b/tests/unit/db/fact-log.test.ts index abce2dc9..f1c226cc 100644 --- a/tests/unit/db/fact-log.test.ts +++ b/tests/unit/db/fact-log.test.ts @@ -186,4 +186,52 @@ describe('fact log — round-trip, framing, reconcile, rotation, scan', () => { await log.sync() expect(log.segmentPaths()).toEqual([]) // only a tail exists — nothing sealed }) + + describe('scanFacts liveness contract (Stage-2 D1)', () => { + it('a wedged store fails LOUDLY within the first-batch bound — never a silent hang', async () => { + // Force a sealed segment (tiny rotateBytes) so the scan must READ from + // storage, then wedge that read: the exact production shape (a + // backlogged brain whose segment read never returned). + const mem: any = new MemoryStorage() + await mem.init() + const wedgeable = new FactLog(mem, { rotateBytes: 1 }) + await wedgeable.open(0) + await wedgeable.append(fact(1)) + await wedgeable.append(fact(2)) // second append rotates → seg 1 sealed + await wedgeable.sync() + + const realRead = mem.readRawBytes.bind(mem) + mem.readRawBytes = (p: string) => + p.includes('facts/seg-') ? new Promise(() => {}) : realRead(p) // hangs forever + + const scan = wedgeable.scanFacts({ firstBatchTimeoutMs: 200 }) + const started = Date.now() + await expect(scan.batches().next()).rejects.toThrow(/no first batch within 200ms/) + expect(Date.now() - started).toBeLessThan(5_000) // bound held, not a hang + }) + + it('a healthy scan is unaffected — first batch well inside the bound, all facts delivered', async () => { + for (let g = 1; g <= 5; g++) await log.append(fact(g)) + await log.sync() + const scan = log.scanFacts({ batchSize: 2 }) + const all: CommitFact[] = [] + for await (const b of scan.batches()) all.push(...b.facts) + expect(all.map((f) => f.generation)).toEqual([1, 2, 3, 4, 5]) + expect(scan.summary().factsYielded).toBe(5) + }) + + it('consumer think-time between pulls never counts against the producer', async () => { + for (let g = 1; g <= 4; g++) await log.append(fact(g)) + await log.sync() + // Bound tighter than the consumer's pause: only the FIRST pull is + // raced, so a slow consumer after batch 1 must not trip the deadline. + const gen = log.scanFacts({ batchSize: 2, firstBatchTimeoutMs: 150 }).batches() + const first = await gen.next() + expect(first.done).toBe(false) + await new Promise((r) => setTimeout(r, 400)) // dawdle past the bound + const second = await gen.next() + expect(second.done).toBe(false) + expect((await gen.next()).done).toBe(true) + }) + }) }) diff --git a/tests/unit/db/generation-segments.test.ts b/tests/unit/db/generation-segments.test.ts new file mode 100644 index 00000000..27ab85cb --- /dev/null +++ b/tests/unit/db/generation-segments.test.ts @@ -0,0 +1,150 @@ +/** + * @module tests/unit/db/generation-segments + * @description The generation-segment store (Stage-2 D1+D3 file format). + * Laws: (1) fold → read round-trips deltas and records byte-faithfully via + * sidecar point-reads; (2) the manifest is the ONLY discovery path — reopen + * reads one file, never a listing; (3) a lost/corrupt sidecar rebuilds from + * its segment loudly, a damaged SEGMENT fails loudly (never silent wrong + * data); (4) D3 reclaim drops whole segments only and bumps compactedBelow; + * (5) the packed digest is deterministic across reopen; (6) immutability — + * fold refuses overlap with sealed ranges. + */ +import { describe, it, expect, beforeEach } from 'vitest' +import { MemoryStorage } from '../../../src/storage/adapters/memoryStorage.js' +import { + GenerationSegmentStore, + SEGMENTS_PREFIX, + type FoldGeneration +} from '../../../src/db/generationSegments.js' + +const UUID = (n: number): string => `00000000-0000-4000-8000-${String(n).padStart(12, '0')}` + +const gen = (g: number, recordCount = 2): FoldGeneration => ({ + generation: g, + timestamp: 1_700_000_000_000 + g, + delta: { generation: g, nouns: [UUID(g)], verbs: [], bytes: 123 + g }, + records: Array.from({ length: recordCount }, (_, i) => ({ + kind: (i % 2 === 0 ? 'noun' : 'verb') as 'noun' | 'verb', + id: UUID(g * 100 + i), + record: { metadata: { noun: 'document', v: g }, vector: { v: [g, i] } } + })) +}) + +describe('db/GenerationSegmentStore — the D1+D3 packed tier', () => { + let storage: MemoryStorage + let store: GenerationSegmentStore + + beforeEach(async () => { + storage = new MemoryStorage() + await storage.init() + store = new GenerationSegmentStore(storage as any) + await store.open() + }) + + it('fold → read round-trips deltas and records via sidecar point-reads', async () => { + const meta = await store.fold([gen(1), gen(2), gen(3)]) + expect(meta).toMatchObject({ firstGeneration: 1, lastGeneration: 3, frames: 3 }) + expect(meta.checksum).toBeGreaterThan(0) + + expect(store.hasGeneration(2)).toBe(true) + expect(store.hasGeneration(4)).toBe(false) + + const d2 = await store.readDelta(2) + expect(d2?.delta).toEqual({ generation: 2, nouns: [UUID(2)], verbs: [], bytes: 125 }) + expect(d2?.timestamp).toBe(1_700_000_000_002) + + const records = await store.readRecords(3) + expect(records).toHaveLength(2) + expect(records![0]).toEqual({ + kind: 'noun', + id: UUID(300), + record: { metadata: { noun: 'document', v: 3 }, vector: { v: [3, 0] } } + }) + // Point read by id, both kinds. + expect(await store.readRecord(3, 'verb', UUID(301))).toEqual({ + metadata: { noun: 'document', v: 3 }, + vector: { v: [3, 1] } + }) + expect(await store.readRecord(3, 'noun', UUID(999))).toBeNull() + }) + + it('reopen discovers everything from the manifest alone — no listing', async () => { + await store.fold([gen(1), gen(2)]) + await store.fold([gen(3), gen(4)]) + + const reopened = new GenerationSegmentStore(storage as any) + await reopened.open() + expect(reopened.segments()).toHaveLength(2) + expect(reopened.hasGeneration(4)).toBe(true) + expect((await reopened.readDelta(1))?.timestamp).toBe(1_700_000_000_001) + }) + + it('a lost sidecar rebuilds from its segment; a damaged segment fails LOUDLY', async () => { + const meta = await store.fold([gen(1), gen(2)]) + const idxPath = `${SEGMENTS_PREFIX}/seg-${String(1).padStart(20, '0')}.idx` + await storage.deleteRawObject(idxPath) + + const reopened = new GenerationSegmentStore(storage as any) + await reopened.open() + // Rebuild path: still serves correct data. + expect((await reopened.readRecords(2))!).toHaveLength(2) + + // Now damage the SEGMENT itself: flip a payload byte → CRC mismatch, loud. + const segPath = `${SEGMENTS_PREFIX}/${meta.file}` + const bytes = (await storage.readRawBytes(segPath))! + bytes[bytes.length - 3] ^= 0xff + await storage.writeRawBytes(segPath, bytes) + const damaged = new GenerationSegmentStore(storage as any) + await damaged.open() + ;(damaged as any).sidecars.clear() + await storage.deleteRawObject(idxPath) // force the sequential rebuild over damaged bytes + await expect(damaged.readRecords(2)).rejects.toThrow(/CRC mismatch|damaged/) + }) + + it('D3 reclaim drops whole segments only and bumps compactedBelow', async () => { + await store.fold([gen(1), gen(2)]) + await store.fold([gen(3), gen(4)]) + await store.fold([gen(5), gen(6)]) + + // Horizon mid-segment-2 (below 4): only segment 1 is FULLY below → drops. + const r1 = await store.dropSegmentsBelow(4) + expect(r1).toEqual({ dropped: 1, compactedBelow: 3 }) + expect(store.hasGeneration(1)).toBe(false) + expect(store.hasGeneration(3)).toBe(true) // partial segment survives whole + + // Bytes actually gone. + expect(await storage.readRawBytes(`${SEGMENTS_PREFIX}/seg-${String(1).padStart(20, '0')}.bgs`)).toBeNull() + + // Horizon past everything: the rest drop; compactedBelow is durable. + const r2 = await store.dropSegmentsBelow(7) + expect(r2.dropped).toBe(2) + const reopened = new GenerationSegmentStore(storage as any) + await reopened.open() + expect(reopened.compactedBelow()).toBe(7) + expect(reopened.segments()).toHaveLength(0) + }) + + it('the packed digest is deterministic across reopen and changes with history', async () => { + await store.fold([gen(1), gen(2), gen(3)]) + const atSeal = await store.digestThroughPacked(3) + const midSegment = await store.digestThroughPacked(2) + expect(atSeal).not.toBeNull() + expect(midSegment).not.toBeNull() + expect(midSegment).not.toBe(atSeal) + + const reopened = new GenerationSegmentStore(storage as any) + await reopened.open() + expect(await reopened.digestThroughPacked(3)).toBe(atSeal) + expect(await reopened.digestThroughPacked(2)).toBe(midSegment) + + await reopened.fold([gen(4)]) + expect(await reopened.digestThroughPacked(4)).not.toBe(atSeal) + }) + + it('sealed segments are immutable — fold refuses overlap, requires ascending input', async () => { + await store.fold([gen(1), gen(2)]) + await expect(store.fold([gen(2), gen(3)])).rejects.toThrow(/overlaps the packed tier/) + await expect(store.fold([gen(4), gen(4)])).rejects.toThrow(/strictly ascending/) + await expect(store.fold([])).rejects.toThrow(/at least one generation/) + }) +})