brainy/src/db/db.ts
David Snelling d02e522a3e feat(8.0): id-normalization (#18) + aggregation min/max delete-safety + RC-safe release
- id-normalization (#18): `brain.newId()` (UUID v7) + v7 default ids; non-UUID string ids are
  transparently normalized to a stable UUID v5 on creation AND every lookup — get/update/remove,
  relate(from,to), related, find({connected}), getMany, removeMany, the transact op-handler, and
  db.with() overlays — with the caller's original key preserved under `_originalId`. The engine only
  ever sees a UUID; real UUIDs pass through untouched. universal/uuid.ts gains v5/v7/isUUID +
  BRAINY_ID_NAMESPACE; new utils/idNormalization.ts (coerceNewEntityId / resolveEntityId).
- aggregation min/max delete-safety: `queryAggregate` no longer leaves a stale min/max after
  deleting the current extreme — min/max now track a value multiset and recompute in-memory (no
  entity scan; that scan was the prior delete-then-hang a consumer reported). Other metrics were
  already exact across deletes. Regression test proves resolve-after-delete + correct new min/max.
- release.sh RC-safe: explicit version arg, prerelease detection (npm `--tag rc` + GitHub
  `--prerelease`), full `test:ci` gate (unit + integration), current-branch push, npm-access
  verification after publish.
- native-engine references point at `@soulcraft/cor` (8.0's partner) in user-facing strings/docs.

Unit 1461/0 · integration 599/0 · tsc clean.
2026-06-20 14:46:40 -07:00

1040 lines
44 KiB
TypeScript

/**
* @module db/db
* @description `Db` — Brainy 8.0's immutable, Datomic-style database value.
*
* A `Db` is a **readonly view pinned at one generation** of a Brainy store.
* It is produced by `brain.now()` (O(1) pin of the current generation),
* `brain.transact()` (pinned at the freshly committed generation),
* `brain.asOf()` (a past generation, a timestamp, or a persisted snapshot
* path), `Brainy.load(path)` (a snapshot opened read-only), and `db.with()`
* (a speculative in-memory overlay).
*
* **Read semantics.** While no transaction has committed past the pinned
* generation, every read delegates straight to the live brain — the pinned
* view IS the current state, and the existing fast paths serve it untouched.
* Once later transactions commit, the `Db` serves the FULL query surface at
* the pinned generation through two complementary paths:
*
* - `get()`, metadata-level `find()`, and filter-based `related()` resolve
* through the generational record layer (changed ids from immutable
* before-images; unchanged ids still ride the live fast path) — no
* materialization cost.
* - Index-accelerated queries (semantic/vector search, graph traversal,
* cursors, aggregation) are served by **at-generation index
* materialization**: on first use, the host rebuilds ephemeral in-memory
* indexes (the same vector/metadata/graph index classes the live brain
* uses) over the exact at-generation record set, caches them on this `Db`,
* and frees them on {@link Db.release}. This costs O(n at G) time and
* memory ONCE per `Db` — the open-core price of historical index queries;
* a native {@link ../plugin.js VersionedIndexProvider} serves the same
* reads from its retained segments without any rebuild.
*
* Speculative `with()` overlays keep one honest boundary: overlay entities
* carry no embeddings, so index-accelerated queries on overlays throw
* {@link SpeculativeOverlayError} instead of returning silently-incomplete
* results.
*
* **History granularity.** Generation records are written per `transact()`
* batch. Single-operation writes (`add`/`update`/`relate`/… outside
* `transact()`) advance the generation counter but do not produce historical
* records, so they remain visible through earlier pins — the documented 8.0
* granularity (see `docs/ADR-001-generational-mvcc.md`, "History
* granularity").
*
* **Lifecycle.** Each `Db` holds one refcounted pin on its generation (and
* on every registered {@link ../plugin.js VersionedIndexProvider}). Call
* {@link Db.release} when done — a `FinalizationRegistry` backstop releases
* leaked pins on garbage collection, but explicit release is what makes
* `compactHistory()` deterministic.
*/
import type {
Entity,
FindParams,
GetOptions,
RelatedParams,
Relation,
Result
} from '../types/brainy.types.js'
import type { StorageAdapter } from '../coreTypes.js'
import { exportGraph } from './portableGraph.js'
import type { ExportSelector, ExportOptions, PortableGraph } from './portableGraph.js'
import {
splitNounMetadataRecord,
splitVerbMetadataRecord
} from '../types/reservedFields.js'
import { v4 as uuidv4 } from '../universal/uuid.js'
import { coerceNewEntityId, resolveEntityId, ORIGINAL_ID_KEY } from '../utils/idNormalization.js'
import { EntityNotFoundError } from '../errors/notFound.js'
import { SpeculativeOverlayError } from './errors.js'
import type { GenerationStore } from './generationStore.js'
import type { ChangedIds, TransactReceipt, TxOperation } from './types.js'
import { entityMatchesFind, resolveEntityField, UnsupportedWhereOperatorError } from './whereMatcher.js'
/**
* @description The query surface a historical materialization exposes back
* to its `Db`: the full live read pipeline of an ephemeral reader brain
* whose storage holds the exact at-generation record set. Produced by
* {@link DbHost.materializeAt}; closed (indexes freed) via `close()` when
* the owning `Db` is released.
*/
export interface HistoricalQueryHandle<T = any> {
/** Full `find()` surface (vector/semantic/graph/cursor/aggregate) at the pinned generation. */
find(query: string | FindParams<T>): Promise<Result<T>[]>
/** Full `related()` surface (including cursor pagination) at the pinned generation. */
related(paramsOrId?: string | RelatedParams): Promise<Relation<T>[]>
/** Free the materialized indexes (closes the ephemeral reader). Idempotent. */
close(): Promise<void>
}
/**
* @description The speculative overlay carried by a `db.with()` value:
* per-id replacement entities/relations (`null` = tombstone). Reads on the
* overlay `Db` consult these maps first, then fall through to the pinned
* base view. Overlays are pure in-memory values — they never touch disk or
* index providers.
*/
export interface SpeculativeOverlay<T = any> {
/** Entity overlays: replacement entity, or `null` for a speculative delete. */
nouns: Map<string, Entity<T> | null>
/** Relation overlays: replacement relation, or `null` for a speculative delete. */
verbs: Map<string, Relation<T> | null>
}
/**
* @description The host surface a `Db` needs from its `Brainy` instance —
* constructed once per brain (see `brainy.ts`). Internal: consumers never
* build one; `Db` values are only created by `Brainy` and `db.with()`.
*/
export interface DbHost<T = any> {
/** The generational record layer of the host brain. */
readonly store: GenerationStore
/** The host brain's storage adapter (portable-export VFS blob bytes). */
readonly storage: StorageAdapter
/** Live `brain.get()` (current-generation fast path). */
get(id: string, options?: GetOptions): Promise<Entity<T> | null>
/** Live `brain.find()` (current-generation fast path). */
find(query: string | FindParams<T>): Promise<Result<T>[]>
/** Live `brain.related()` (current-generation fast path). */
related(paramsOrId?: string | RelatedParams): Promise<Relation<T>[]>
/**
* Resolve a `generation | Date` to a concrete generation (+ timestamp) via the
* brain's shared `asOf` resolver — so `since(gen|Date)` shares `asOf`'s
* reachability and `Date` semantics. `exclusive` pins the generation before the
* resolved one.
*/
resolveGeneration(
target: number | Date,
options?: { exclusive?: boolean }
): Promise<{ generation: number; timestamp: number }>
/** Materialize an entity from a generation record's raw stored objects. */
entityFromRecord(
id: string,
record: { metadata: any; vector: any | null },
includeVectors: boolean
): Promise<Entity<T>>
/** Materialize a relation from a generation record's raw stored objects. */
relationFromRecord(id: string, record: { metadata: any; vector: any | null }): Relation<T> | null
/** Snapshot the store at `generation` into `targetPath` (throws if the pin is stale). */
persistPinned(targetPath: string, generation: number): Promise<void>
/**
* Build the at-`generation` index materialization: an ephemeral in-memory
* reader over the exact record set at that generation, serving the full
* query surface. O(n at G) — called at most once per `Db` (cached by the
* caller) and freed via the returned handle's `close()`.
*/
materializeAt(generation: number): Promise<HistoricalQueryHandle<T>>
/** Add one refcounted pin (store + versioned providers) on `generation`. */
pinGeneration(generation: number): void
/** Release one refcounted pin (store + versioned providers) on `generation`. */
releaseGeneration(generation: number): void
/** Register a `Db` with the GC-backstop finalization registry. */
registerDbForFinalization(db: Db<T>, generation: number, closeOnRelease?: () => Promise<void>): void
/** Unregister a `Db` after an explicit release (no double-release on GC). */
unregisterDbFromFinalization(db: Db<T>): void
}
/**
* @description Internal constructor arguments for {@link Db}. The pin on
* `generation` is taken by the creator (`Brainy` or `db.with()`) **before**
* construction; the constructor only registers the GC backstop.
*/
export interface DbInit<T = any> {
/** The host surface (one per brain). */
host: DbHost<T>
/** The pinned generation. */
generation: number
/** The view's timestamp (ms since epoch) — see {@link Db.timestamp}. */
timestamp: number
/** Per-operation receipt, present only on `transact()`-produced values. */
receipt?: TransactReceipt
/** Speculative overlay, present only on `with()`-produced values. */
overlay?: SpeculativeOverlay<T>
/** Extra teardown on release (e.g. closing an owned snapshot brain). */
closeOnRelease?: () => Promise<void>
}
/**
* @description An immutable, generation-pinned view of a Brainy store. See
* the module documentation for the full read-semantics contract.
*
* @example
* const db = brain.now() // O(1) pin
* await brain.transact([{ op: 'update', id, metadata: { v: 2 } }])
* await db.get(id) // still sees v: 1 — pinned
* await brain.get(id) // sees v: 2 — live
* await db.release() // unpin (enables compaction)
*/
export class Db<T = any> {
private readonly host: DbHost<T>
private readonly gen: number
private readonly ts: number
private readonly overlay?: SpeculativeOverlay<T>
private readonly closeOnRelease?: () => Promise<void>
private isReleased = false
/**
* Cached at-generation index materialization (built lazily by the first
* index-accelerated query at a historical pin; freed on release()).
*/
private materializedHandle?: Promise<HistoricalQueryHandle<T>>
/**
* Per-operation receipt (committed generation, timestamp, resolved ids in
* input order). Present only on values returned by `brain.transact()`.
*/
public readonly receipt?: TransactReceipt
/**
* @param init - Internal construction arguments. `Db` values are created
* by `Brainy` (`now`/`transact`/`asOf`/`load`) and `db.with()` — never
* directly by consumers.
*/
constructor(init: DbInit<T>) {
this.host = init.host
this.gen = init.generation
this.ts = init.timestamp
this.receipt = init.receipt
this.overlay = init.overlay
this.closeOnRelease = init.closeOnRelease
this.host.registerDbForFinalization(this, this.gen, this.closeOnRelease)
}
/** The generation this view is pinned at. */
get generation(): number {
return this.gen
}
/**
* @internal Same-instance guard for cross-`Db` operations like
* `Brainy.diff()`: whether this view is backed by `store`. Lets `Brainy`
* reject a `Db` endpoint from a different brain without exposing the private
* host.
*/
belongsToStore(store: GenerationStore): boolean {
return this.host.store === store
}
/**
* The view's wall-clock timestamp (ms since epoch): pin time for `now()`,
* commit time for `transact()`, and the resolved commit time for `asOf()`.
*/
get timestamp(): number {
return this.ts
}
/** Whether {@link Db.release} has been called (released views throw on use). */
get released(): boolean {
return this.isReleased
}
/** Whether this view carries a speculative `with()` overlay. */
get speculative(): boolean {
return this.overlay !== undefined
}
// ==========================================================================
// Reads
// ==========================================================================
/**
* @description Get an entity by id **as of this view's generation**.
* Overlay entries win (speculative views); ids untouched since the pin ride
* the live fast path; ids changed by later transactions resolve from
* immutable generation records. Always correct at the pinned generation.
*
* @param id - The entity id.
* @param options - Same options as `brain.get()` (`includeVectors`).
* @returns The entity as of this generation, or `null`.
*/
async get(id: string, options?: GetOptions): Promise<Entity<T> | null> {
this.assertUsable('get')
// Id normalization (8.0): resolve a natural key to the canonical UUID the
// write path stored, so this view reads by natural key consistently. A real
// UUID passes through. Overlay keys are canonical (see with()).
id = resolveEntityId(id)
if (this.overlay && this.overlay.nouns.has(id)) {
return this.overlay.nouns.get(id) ?? null
}
if (!this.isHistorical()) {
return this.host.get(id, options)
}
const resolved = await this.host.store.resolveAt('noun', id, this.gen)
if (resolved.source === 'current') {
return this.host.get(id, options)
}
if (resolved.source === 'absent' || resolved.metadata === null) {
// Live semantics: an entity without metadata is not a live entity.
return null
}
return this.host.entityFromRecord(
id,
{ metadata: resolved.metadata, vector: resolved.vector },
options?.includeVectors ?? false
)
}
/**
* @description The full `find()` surface **as of this view's generation**.
*
* Routing:
* - **Current generation, no overlay** — delegates to `brain.find()`
* untouched (the existing fast paths).
* - **Historical generation** — metadata dimensions (`type`, `subtype`,
* `where`, `service`, `excludeVFS`, `orderBy`/`order`,
* `limit`/`offset`) are computed from the generational record layer
* directly (no materialization cost): the live index serves unchanged
* ids, and per-entity evaluation of the same filters covers
* record-resolved ids — set-correct at the pinned generation.
* Index-accelerated dimensions (`query`, `vector`, `near`, `connected`,
* `cursor`, `aggregate`, `includeRelations`, non-metadata search modes)
* are served by the at-generation index materialization — built lazily
* on first use (O(n at G) time and memory, once per `Db`; see the module
* doc), then cached until {@link Db.release}.
* - **Speculative overlay** — metadata dimensions only; index-accelerated
* dimensions throw {@link SpeculativeOverlayError} (overlay entities
* carry no embeddings — see the error's documentation).
*
* Result ordering is deterministic when `orderBy` is supplied; without it,
* record-path results list live-index matches before record-resolved
* matches, while materialized results follow the live engine's ordering.
*
* @param query - A `FindParams` object, or a string (semantic search).
* @returns Matching results as of this generation (score `1.0` for
* record-resolved metadata matches, mirroring live metadata-only finds).
*/
async find(query: string | FindParams<T>): Promise<Result<T>[]> {
this.assertUsable('find')
const params: FindParams<T> = typeof query === 'string' ? { query } : query
const historical = this.isHistorical()
if (!historical && !this.overlay) {
return this.host.find(query)
}
if (this.overlay) {
this.assertOverlayCompatibleFind(params)
} else if (findRequiresIndexes(params)) {
const materialized = await this.materialize()
return materialized.find(params)
}
const limit = params.limit ?? 10
const offset = params.offset ?? 0
// Ids whose live-index answer is NOT valid at this generation.
const changedNouns = historical
? (await this.host.store.changedBetween(this.gen, this.host.store.committedGeneration())).nouns
: []
const overlayNouns = this.overlay?.nouns ?? new Map<string, Entity<T> | null>()
const excluded = new Set<string>([...changedNouns, ...overlayNouns.keys()])
try {
// Over-fetch from the live index so dropping superseded ids cannot
// starve the requested page, then merge and re-window.
const base = await this.host.find({
...params,
limit: limit + offset + excluded.size,
offset: 0
})
const merged = base.filter((result) => !excluded.has(result.id))
for (const id of changedNouns) {
if (overlayNouns.has(id)) continue // The overlay supersedes history.
const resolved = await this.host.store.resolveAt('noun', id, this.gen)
let entity: Entity<T> | null = null
if (resolved.source === 'record' && resolved.metadata !== null) {
entity = await this.host.entityFromRecord(
id,
{ metadata: resolved.metadata, vector: resolved.vector },
false
)
} else if (resolved.source === 'current') {
// Defensive: changed ids always resolve to a record or absent, but
// a 'current' answer is still served correctly from the live path.
entity = await this.host.get(id)
}
if (entity && entityMatchesFind(entity as Entity, params as FindParams)) {
merged.push(resultFromEntity(entity))
}
}
for (const [, entity] of overlayNouns) {
if (entity === null) continue // Speculative delete.
if (entityMatchesFind(entity as Entity, params as FindParams)) {
merged.push(resultFromEntity(entity))
}
}
if (params.orderBy) {
sortResultsBy(merged, params.orderBy, params.order ?? 'asc')
}
return merged.slice(offset, offset + limit)
} catch (err) {
if (err instanceof UnsupportedWhereOperatorError) {
// The record-path's per-entity matcher doesn't implement this
// where-operator. On an overlay that is a hard boundary; at a
// historical generation the materialization serves it via the full
// live query engine.
if (this.overlay) {
throw new SpeculativeOverlayError(
`metadata find with where-operator '${err.operator}'`,
this.gen
)
}
const materialized = await this.materialize()
return materialized.find(params)
}
throw err
}
}
/**
* @description Serialize part or all of this database value into a portable
* `PortableGraph` document, read **as of this view's generation**. Because `export`
* lives on the immutable `Db`, it composes with every way of obtaining one:
* `brain.now().export(sel)` (current), `(await brain.asOf(g)).export(sel)`
* (time-travel export), and `brain.now().with(ops).export(sel)` (what-if export).
*
* The document is portable JSON, versioned (`formatVersion`), and current-state
* (no generation history) — distinct from `persist()` (native whole-brain snapshot
* that preserves history). Restore with `brain.import(backup)`.
*
* @param selector - WHAT to export (omit for the whole brain). See {@link ExportSelector}.
* @param options - HOW to export (vectors / VFS bytes / edge policy). See {@link ExportOptions}.
* @returns A versioned, portable `PortableGraph` document.
* @example
* const backup = await brain.now().export({ collection: id }, { includeVectors: true })
*/
async export(selector: ExportSelector = {}, options: ExportOptions = {}): Promise<PortableGraph> {
this.assertUsable('export')
return exportGraph(this, this.host.storage, selector, options)
}
/**
* @description Relationships **as of this view's generation** — the `Db`
* counterpart of `brain.related()` (same string-id shorthand and
* filter surface). Relations whose edges changed after the pin are
* resolved from generation records; overlay relations (speculative
* `relate`/`unrelate`) and cascade tombstones (relations touching a
* speculatively deleted entity) are applied on top. Cursor pagination is
* index-only: at a historical generation it is served by the
* at-generation index materialization (O(n at G) once per `Db`); on a
* speculative overlay it throws {@link SpeculativeOverlayError}.
*
* @param paramsOrId - An entity id (shorthand for `{ from: id }`) or a
* `RelatedParams` filter object.
* @returns Relations as of this generation.
*/
async related(paramsOrId?: string | RelatedParams): Promise<Relation<T>[]> {
this.assertUsable('related')
const rawParams: RelatedParams =
typeof paramsOrId === 'string' ? { from: paramsOrId } : (paramsOrId ?? {})
// Id normalization (8.0): resolve the anchor id(s) so this view traverses by
// natural key consistently with the live engine. Real UUIDs pass through.
const params: RelatedParams = {
...rawParams,
...(rawParams.from !== undefined && { from: resolveEntityId(rawParams.from) }),
...(rawParams.to !== undefined && { to: resolveEntityId(rawParams.to) })
}
const historical = this.isHistorical()
if (!historical && !this.overlay) {
return this.host.related(params)
}
if (params.cursor !== undefined) {
if (this.overlay) {
throw new SpeculativeOverlayError('cursor pagination on related()', this.gen)
}
const materialized = await this.materialize()
return materialized.related(params)
}
const limit = params.limit ?? 100
const offset = params.offset ?? 0
const changedVerbs = historical
? (await this.host.store.changedBetween(this.gen, this.host.store.committedGeneration())).verbs
: []
const overlayVerbs = this.overlay?.verbs ?? new Map<string, Relation<T> | null>()
const excluded = new Set<string>([...changedVerbs, ...overlayVerbs.keys()])
const base = await this.host.related({
...params,
limit: limit + offset + excluded.size,
offset: 0
})
let merged = base.filter((relation) => !excluded.has(relation.id))
for (const id of changedVerbs) {
if (overlayVerbs.has(id)) continue
const resolved = await this.host.store.resolveAt('verb', id, this.gen)
if (resolved.source !== 'record') continue
const relation = this.host.relationFromRecord(id, {
metadata: resolved.metadata,
vector: resolved.vector
})
if (relation && relationMatchesParams(relation, params)) {
merged.push(relation)
}
}
for (const [, relation] of overlayVerbs) {
if (relation === null) continue // Speculative unrelate.
if (relationMatchesParams(relation, params)) {
merged.push(relation)
}
}
// Cascade semantics for speculative deletes: a relation whose endpoint
// is tombstoned in the overlay is gone in this view, exactly as
// brain.remove() cascades on the durable path.
if (this.overlay) {
const tombstoned = new Set<string>()
for (const [id, entity] of this.overlay.nouns) {
if (entity === null) tombstoned.add(id)
}
if (tombstoned.size > 0) {
merged = merged.filter(
(relation) => !tombstoned.has(relation.from) && !tombstoned.has(relation.to)
)
}
}
return merged.slice(offset, offset + limit)
}
// ==========================================================================
// Derived views
// ==========================================================================
/**
* @description Speculative write: returns a NEW `Db` whose reads see the
* given transaction data applied **in memory, on top of this view** —
* Datomic's `with`. Nothing touches disk, the generation counter, or index
* providers; the underlying brain and this view are untouched. Use it to
* answer "what would the store look like if…" questions, then call
* `brain.transact()` with the same operations to make it real.
*
* Speculative semantics (documented deltas from the durable paths):
* - `add` without an explicit `vector` produces an entity with an empty
* stub vector — speculative entities are not semantically searchable
* (`with()` never invokes the embedder).
* - `remove` cascades on the read side: relations touching the removed
* entity disappear from `related()` without being enumerated.
* - `relate` deduplicates against the edges visible in this view (overlay
* first, then the record layer), mirroring `brain.relate()`.
* - Brain-level vocabulary/subtype enforcement does not run — overlays
* never persist, so there is nothing to protect.
*
* The returned view takes its own pin on this generation; release both
* views independently.
*
* @param ops - The same declarative operations `brain.transact()` accepts.
* @returns A new speculative `Db` over this view.
* @throws EntityNotFoundError when an operation references a missing
* entity, mirroring the durable path's planning errors.
*/
async with(ops: TxOperation<T>[]): Promise<Db<T>> {
this.assertUsable('with')
if (!Array.isArray(ops) || ops.length === 0) {
throw new Error('with(): provide a non-empty array of transaction operations')
}
// Child overlay starts as a copy of this view's overlay (chained with()).
const overlay: SpeculativeOverlay<T> = {
nouns: new Map(this.overlay?.nouns ?? []),
verbs: new Map(this.overlay?.verbs ?? [])
}
// Reads during planning must see "this view + overlay so far".
const speculativeGet = async (id: string): Promise<Entity<T> | null> => {
if (overlay.nouns.has(id)) return overlay.nouns.get(id) ?? null
return this.get(id)
}
for (const op of ops) {
switch (op.op) {
case 'add': {
// Reserved-field normalization — mirror of the brain.transact()
// write path: user-settable fields lift to their dedicated field
// (top-level wins), system-managed fields drop, and the entity's
// metadata bag carries ONLY custom fields. Speculative views skip
// the one-shot warnings — committing the same ops through
// `brain.transact()` warns on the real write path.
const { reserved, custom } = splitNounMetadataRecord(
op.metadata as Record<string, unknown> | undefined
)
const confidence =
op.confidence ?? (typeof reserved.confidence === 'number' ? reserved.confidence : undefined)
const weight =
op.weight ?? (typeof reserved.weight === 'number' ? reserved.weight : undefined)
const subtype =
op.subtype ?? (typeof reserved.subtype === 'string' ? reserved.subtype : undefined)
const service =
op.service ?? (typeof reserved.service === 'string' ? reserved.service : undefined)
// Id normalization (8.0) — mirror of the committed transact() add
// path: a natural key coerces to a STABLE UUID (v5), preserving the
// original under ORIGINAL_ID_KEY; a real UUID passes through; no id
// mints a fresh id so the overlay keys match the durable path.
const { id, originalId } = coerceNewEntityId(op.id)
const now = Date.now()
overlay.nouns.set(id, {
id,
vector: op.vector ?? [],
type: op.type,
...(subtype !== undefined && { subtype }),
data: op.data,
metadata: {
...(custom as object),
...(originalId !== undefined && { [ORIGINAL_ID_KEY]: originalId })
} as T,
...(service !== undefined && { service }),
createdAt: now,
updatedAt: now,
...(confidence !== undefined && { confidence }),
...(weight !== undefined && { weight }),
_rev: 1
})
break
}
case 'update': {
// Id normalization (8.0): resolve a natural key to the canonical UUID
// the write path stored. A real UUID passes through.
const updateId = resolveEntityId(op.id)
const base = await speculativeGet(updateId)
if (!base) {
throw new EntityNotFoundError(
updateId,
`with(): entity ${updateId} not found at generation ${this.gen}`
)
}
// Same reserved-field normalization as the committed update path.
const { reserved, custom } = splitNounMetadataRecord(
op.metadata as Record<string, unknown> | undefined
)
const confidence =
op.confidence ?? (typeof reserved.confidence === 'number' ? reserved.confidence : undefined)
const weight =
op.weight ?? (typeof reserved.weight === 'number' ? reserved.weight : undefined)
const subtype =
op.subtype ?? (typeof reserved.subtype === 'string' ? reserved.subtype : undefined)
const mergedMetadata =
op.merge !== false
? ({ ...(base.metadata as object), ...custom } as T)
: ((op.metadata !== undefined ? custom : base.metadata) as T)
overlay.nouns.set(updateId, {
...base,
...(op.type !== undefined && { type: op.type }),
...(subtype !== undefined && { subtype }),
...(op.data !== undefined && { data: op.data }),
...(op.vector !== undefined && { vector: op.vector }),
...(confidence !== undefined && { confidence }),
...(weight !== undefined && { weight }),
metadata: mergedMetadata,
updatedAt: Date.now(),
_rev: (base._rev ?? 1) + 1
})
break
}
case 'remove': {
// Id normalization (8.0): resolve a natural key to the canonical UUID
// the write path stored. A real UUID passes through.
const removeId = resolveEntityId(op.id)
overlay.nouns.set(removeId, null)
// Tombstone overlay relations touching the removed entity; base
// relations are cascade-filtered at read time in related().
for (const [verbId, relation] of overlay.verbs) {
if (relation && (relation.from === removeId || relation.to === removeId)) {
overlay.verbs.set(verbId, null)
}
}
break
}
case 'relate': {
// Id normalization (8.0) — mirror of relate(): resolve BOTH endpoints
// to the canonical UUID the write path stored. Real UUIDs pass through.
const relFrom = resolveEntityId(op.from)
const relTo = resolveEntityId(op.to)
const from = await speculativeGet(relFrom)
const to = await speculativeGet(relTo)
if (!from) {
throw new EntityNotFoundError(relFrom, `with(): source entity ${relFrom} not found`)
}
if (!to) {
throw new EntityNotFoundError(relTo, `with(): target entity ${relTo} not found`)
}
// Dedupe against the view (overlay first, then the edges visible
// at this generation via the record layer) — mirror of relate().
let duplicate: Relation<T> | undefined
for (const relation of overlay.verbs.values()) {
if (relation && relation.from === relFrom && relation.to === relTo && relation.type === op.type) {
duplicate = relation
break
}
}
if (!duplicate) {
const existing = await this.related({ from: relFrom, type: op.type })
duplicate = existing.find((relation) => relation.to === relTo)
}
if (duplicate) break
// Reserved-field normalization — relationship mirror of the add
// op above (and of the committed relate() path).
const { reserved, custom } = splitVerbMetadataRecord(
op.metadata as Record<string, unknown> | undefined
)
const confidence =
op.confidence ?? (typeof reserved.confidence === 'number' ? reserved.confidence : undefined)
const weight =
op.weight ?? (typeof reserved.weight === 'number' ? reserved.weight : undefined)
const subtype =
op.subtype ?? (typeof reserved.subtype === 'string' ? reserved.subtype : undefined)
const service =
op.service ?? (typeof reserved.service === 'string' ? reserved.service : undefined)
const id = uuidv4()
overlay.verbs.set(id, {
id,
from: relFrom,
to: relTo,
type: op.type,
...(subtype !== undefined && { subtype }),
weight: weight ?? 1.0,
...(confidence !== undefined && { confidence }),
...(op.data !== undefined && { data: op.data }),
metadata: custom as T,
...(service !== undefined && { service }),
createdAt: Date.now()
})
if (op.bidirectional) {
const reverseId = uuidv4()
overlay.verbs.set(reverseId, {
id: reverseId,
from: relTo,
to: relFrom,
type: op.type,
...(subtype !== undefined && { subtype }),
weight: weight ?? 1.0,
...(confidence !== undefined && { confidence }),
...(op.data !== undefined && { data: op.data }),
metadata: custom as T,
...(service !== undefined && { service }),
createdAt: Date.now()
})
}
break
}
case 'unrelate': {
overlay.verbs.set(op.id, null)
break
}
default: {
const exhaustive: never = op
throw new Error(`with(): unknown operation ${JSON.stringify(exhaustive)}`)
}
}
}
this.host.pinGeneration(this.gen)
return new Db<T>({
host: this.host,
generation: this.gen,
timestamp: Date.now(),
overlay
})
}
/**
* @description The ids changed by committed transactions in the interval
* `(lowerBound, this.generation]` — the diff between an earlier state and this
* view. The lower bound is **exclusive** (contrast `transactionLog`'s inclusive
* window). Single-operation writes between commits are not reflected (documented
* 8.0 history granularity).
*
* The lower bound may be:
* - **a `Db`** — an earlier view of the SAME store (its pinned generation);
* - **a generation number** — used directly as the exclusive lower bound;
* - **a `Date`** — resolved to the generation committed at or before it.
*
* `db.since(prior)` equals `db.since(prior.generation)` by construction.
*
* @param lowerBound - An earlier `Db`, a generation number, or a `Date`.
* @returns Changed entity and relation ids, sorted.
* @throws RangeError when the resolved lower bound is newer than this view.
* @throws Error when a `Db` lower bound belongs to a different store.
* @throws GenerationCompactedError when a number/`Date` lower bound is below the
* compaction horizon.
* @example
* const before = brain.now()
* await brain.transact(ops)
* await brain.now().since(before) // ids changed by the transaction
* await brain.now().since(before.generation)
* await brain.now().since(new Date(Date.now() - 3_600_000))
*/
async since(lowerBound: Db<T> | number | Date): Promise<ChangedIds> {
this.assertUsable('since')
let fromGen: number
if (lowerBound instanceof Db) {
if (lowerBound.host.store !== this.host.store) {
throw new Error('since(): both Db values must come from the same Brainy instance')
}
fromGen = lowerBound.gen
} else {
// number = exclusive lower-bound generation; Date resolves via the shared
// asOf resolver (same reachability gate). changedBetween treats fromGen as
// exclusive, so since(db) === since(db.generation).
fromGen = (await this.host.resolveGeneration(lowerBound)).generation
}
if (fromGen > this.gen) {
throw new RangeError(
`since(): lower-bound generation ${fromGen} is newer than this view ` +
`(generation ${this.gen}). Pass an earlier generation/Date, or call newerDb.since(olderDb).`
)
}
return this.host.store.changedBetween(fromGen, this.gen)
}
// ==========================================================================
// Durability
// ==========================================================================
/**
* @description Snapshot this view to `path` as a self-contained store:
* flush, then hard-link every immutable file into the target
* (Cassandra-style — instant and space-shared; cross-device targets fall
* back to byte copies, and the small append-in-place file list is always
* byte-copied). The result opens with `Brainy.load(path)` with the full
* query surface, and later mutations of the source can never alter it —
* rewrites swap inodes, the snapshot keeps the old bytes.
*
* `persist()` requires this view to still be the store's **latest**
* generation (snapshotting captures current bytes): pin with `brain.now()`
* and persist before further writes. A view that history has moved past
* throws {@link GenerationConflictError}; speculative overlays throw
* {@link SpeculativeOverlayError} (commit them with `brain.transact()`
* first).
*
* @param path - Absolute directory for the snapshot (created; must be
* empty or absent).
* @throws GenerationConflictError when this view is no longer the latest
* generation.
* @throws SpeculativeOverlayError when this view is a speculative overlay.
*/
async persist(path: string): Promise<void> {
this.assertUsable('persist')
if (this.overlay) {
throw new SpeculativeOverlayError('persist', this.gen)
}
await this.host.persistPinned(path, this.gen)
}
// ==========================================================================
// Lifecycle
// ==========================================================================
/**
* @description Release this view's pin (store + versioned index
* providers) and free its at-generation index materialization, if one was
* built. Idempotent. After release, every read throws. Views from
* `Brainy.load()` / `asOf(path)` also close their underlying read-only
* brain here. A `FinalizationRegistry` backstop releases leaked pins (and
* materializations) when a `Db` is garbage-collected, but explicit
* release is what makes `compactHistory()` deterministic — prefer it.
*/
async release(): Promise<void> {
if (this.isReleased) return
this.isReleased = true
this.host.unregisterDbFromFinalization(this)
this.host.releaseGeneration(this.gen)
if (this.materializedHandle) {
// A failed materialization already surfaced to the query that
// triggered it; release() must still succeed.
const handle = await this.materializedHandle.catch(() => null)
if (handle) await handle.close()
}
if (this.closeOnRelease) {
await this.closeOnRelease()
}
}
// ==========================================================================
// Internals
// ==========================================================================
/** Whether any transaction committed past the pinned generation. */
private isHistorical(): boolean {
return this.host.store.hasCommittedAfter(this.gen)
}
/**
* Build (once) and cache the at-generation index materialization. The
* first index-accelerated query at a historical pin pays the O(n at G)
* build; every later one reuses the cached handle until release(). The
* GC-backstop registration is refreshed so a leaked `Db` also closes its
* materialized reader (whose flush timers would otherwise outlive it).
*/
private materialize(): Promise<HistoricalQueryHandle<T>> {
if (!this.materializedHandle) {
this.materializedHandle = this.host.materializeAt(this.gen).then((handle) => {
this.host.unregisterDbFromFinalization(this)
this.host.registerDbForFinalization(this, this.gen, async () => {
await handle.close()
if (this.closeOnRelease) await this.closeOnRelease()
})
return handle
})
// A failed build must not poison the cache — the next query retries.
this.materializedHandle = this.materializedHandle.catch((err) => {
this.materializedHandle = undefined
throw err
})
}
return this.materializedHandle
}
/** Throw on use-after-release. */
private assertUsable(method: string): void {
if (this.isReleased) {
throw new Error(
`Cannot call ${method}() on a released Db (generation ${this.gen}). ` +
`Pin a fresh view with brain.now() or brain.asOf().`
)
}
}
/**
* Reject find() dimensions that require index machinery a speculative
* overlay cannot answer (overlay entities carry no embeddings and are in
* no index — see {@link SpeculativeOverlayError}).
*/
private assertOverlayCompatibleFind(params: FindParams<T>): void {
for (const [capability, present] of indexOnlyFindDimensions(params)) {
if (present) {
throw new SpeculativeOverlayError(capability, this.gen)
}
}
}
}
/**
* @description The find() dimensions that only index machinery can answer
* (everything beyond metadata filters + ordering + offset/limit windows),
* as `[capability, present]` pairs for the given params.
*/
function indexOnlyFindDimensions(params: FindParams): Array<[string, boolean]> {
return [
['semantic query', params.query !== undefined],
['vector search', params.vector !== undefined],
['proximity search (near)', params.near !== undefined],
['graph traversal (connected)', params.connected !== undefined],
['cursor pagination', params.cursor !== undefined],
['aggregation', params.aggregate !== undefined],
['relation expansion (includeRelations)', params.includeRelations === true],
[
`search mode '${params.mode ?? params.searchMode}'`,
(params.mode !== undefined && params.mode !== 'metadata' && params.mode !== 'auto') ||
(params.searchMode !== undefined && params.searchMode !== 'auto')
]
]
}
/**
* @description Whether the find() params include any index-only dimension —
* the routing predicate that decides between the record path (cheap,
* metadata-only) and the at-generation index materialization at historical
* generations.
*/
function findRequiresIndexes(params: FindParams): boolean {
return indexOnlyFindDimensions(params).some(([, present]) => present)
}
/**
* @description Build a `Result` row from a record/overlay-resolved entity,
* mirroring the live metadata-only find path (flattened fields, score `1.0`).
*/
function resultFromEntity<T>(entity: Entity<T>): Result<T> {
return {
id: entity.id,
score: 1.0,
type: entity.type,
subtype: entity.subtype,
metadata: entity.metadata,
data: entity.data,
confidence: entity.confidence,
weight: entity.weight,
_rev: entity._rev,
entity
}
}
/**
* @description In-place stable sort of merged results by a find() `orderBy`
* field, mirroring live ordering semantics (`asc` default, undefined values
* last in both directions).
*/
function sortResultsBy<T>(results: Result<T>[], orderBy: string, order: 'asc' | 'desc'): void {
const direction = order === 'desc' ? -1 : 1
results.sort((a, b) => {
const va = resolveEntityField(a.entity as Entity, orderBy)
const vb = resolveEntityField(b.entity as Entity, orderBy)
if (va === undefined && vb === undefined) return 0
if (va === undefined) return 1
if (vb === undefined) return -1
if (typeof va === 'number' && typeof vb === 'number') return (va - vb) * direction
const sa = String(va)
const sb = String(vb)
return (sa < sb ? -1 : sa > sb ? 1 : 0) * direction
})
}
/**
* @description Filter one relation against `RelatedParams`, mirroring
* the storage-level filter `brain.related()` builds (`from` → sourceId,
* `to` → targetId, type/subtype set membership, service equality).
*/
function relationMatchesParams<T>(relation: Relation<T>, params: RelatedParams): boolean {
if (params.from !== undefined && relation.from !== params.from) return false
if (params.to !== undefined && relation.to !== params.to) return false
if (params.type !== undefined) {
const types = Array.isArray(params.type) ? params.type : [params.type]
if (!types.includes(relation.type)) return false
}
if (params.subtype !== undefined) {
const subtypes = Array.isArray(params.subtype) ? params.subtype : [params.subtype]
if (relation.subtype === undefined || !subtypes.includes(relation.subtype)) return false
}
if (params.service !== undefined && relation.service !== params.service) return false
return true
}