feat(8.0): thread commit generation through the graph-write provider contract

Graph time-travel needs an edge's existence recorded per generation so
db.asOf(g) hops resolve historically correct endpoints. The metadata layer
already threads brainy's commit generation per write; the graph write path did
not, leaving a versioned verb-endpoint store unable to answer "which edges
existed at generation g".

- GraphIndexProvider.addVerb/removeVerb gain a `generation: bigint` parameter
  (the same watermark the storage layer stamps onto the record). A provider with
  a per-generation edge chain stamps the edge at that generation; the JS baseline
  has no such chain and accepts-and-ignores it — graph time-travel is a
  native-provider capability, and the open-core path serves edges as-of-now (the
  one documented graph time-travel limitation).
- The two graph transaction operations resolve the generation via a thunk at
  EXECUTE time: the generation store assigns the batch generation only once the
  commit begins executing, after the operations are planned. The same generation
  is reused for an operation's rollback half.
- All graph-write call sites pass the in-flight generation.

Adds a spy-provider test proving the threading, execute-time resolution, and
forward/rollback generation reuse. The JS index ignores the value, so behaviour
is unchanged: unit 1402/1402, db-mvcc 25/25, bigint-contract relate/unrelate 10/10.
This commit is contained in:
David Snelling 2026-06-16 09:41:59 -07:00
parent b26d3d42b3
commit 0951fa1da0
6 changed files with 195 additions and 26 deletions

View file

@ -283,6 +283,17 @@ export class Brainy<T = any> implements BrainyInterface<T> {
* `compactHistory()` and the `Db` value type.
*/
private generationStore!: GenerationStore
/**
* Resolves the in-flight write generation as a BigInt, for stamping graph
* edges via the {@link GraphIndexProvider} contract. Passed to every
* `AddToGraphIndexOperation`/`RemoveFromGraphIndexOperation` and evaluated
* when the operation executes inside a `transact()` batch the generation
* store has assigned the batch generation by then; for single-op writes it
* reads the post-write watermark. The arrow body reads `generationStore`
* lazily, so it is safe to define before `init()` assigns the store.
*/
private readonly graphWriteGeneration = (): bigint =>
BigInt(this.generationStore.generation())
/** Lazily built host surface shared by every `Db` value of this brain. */
private _dbHost?: DbHost<T>
/**
@ -2188,7 +2199,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
// rollback can re-add through the BigInt addVerb contract)
const { sourceInt, targetInt } = this.resolveVerbEndpointInts(verb)
tx.addOperation(
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt)
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt, this.graphWriteGeneration)
)
// Delete verb metadata
tx.addOperation(
@ -2580,6 +2591,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
tx.addOperation(
new AddToGraphIndexOperation(
this.graphIndex, verb, sourceInt, targetInt,
this.graphWriteGeneration,
(verbInt) => this.cacheVerbInt(verbInt, id)
)
)
@ -2618,6 +2630,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
tx.addOperation(
new AddToGraphIndexOperation(
this.graphIndex, reverseVerb, targetInt, sourceInt,
this.graphWriteGeneration,
(verbInt) => this.cacheVerbInt(verbInt, reverseId)
)
)
@ -2660,7 +2673,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
if (verb && endpointInts) {
tx.addOperation(
new RemoveFromGraphIndexOperation(
this.graphIndex, verb, endpointInts.sourceInt, endpointInts.targetInt
this.graphIndex, verb, endpointInts.sourceInt, endpointInts.targetInt, this.graphWriteGeneration
)
)
}
@ -2785,12 +2798,13 @@ export class Brainy<T = any> implements BrainyInterface<T> {
if (typeChanged && reindexInts) {
tx.addOperation(
new RemoveFromGraphIndexOperation(
this.graphIndex, existing, reindexInts.sourceInt, reindexInts.targetInt
this.graphIndex, existing, reindexInts.sourceInt, reindexInts.targetInt, this.graphWriteGeneration
)
)
tx.addOperation(
new AddToGraphIndexOperation(
this.graphIndex, verbForIndex, reindexInts.sourceInt, reindexInts.targetInt,
this.graphWriteGeneration,
(verbInt) => this.cacheVerbInt(verbInt, params.id)
)
)
@ -4391,7 +4405,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
for (const verb of allVerbs) {
const { sourceInt, targetInt } = this.resolveVerbEndpointInts(verb)
tx.addOperation(
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt)
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt, this.graphWriteGeneration)
)
tx.addOperation(
new DeleteVerbMetadataOperation(this.storage, verb.id)
@ -5977,7 +5991,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
for (const verb of cascade.values()) {
const { sourceInt, targetInt } = this.resolveVerbEndpointInts(verb)
plan.operations.push(
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt),
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt, this.graphWriteGeneration),
new DeleteVerbMetadataOperation(this.storage, verb.id)
)
plan.touchedVerbs.push(verb.id)
@ -6103,7 +6117,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
targetId: params.to
}),
new SaveVerbMetadataOperation(this.storage, id, verbMetadata),
new AddToGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt, (verbInt) =>
new AddToGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt, this.graphWriteGeneration, (verbInt) =>
this.cacheVerbInt(verbInt, id)
)
)
@ -6131,7 +6145,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
targetId: params.from
}),
new SaveVerbMetadataOperation(this.storage, reverseId, verbMetadata),
new AddToGraphIndexOperation(this.graphIndex, reverseVerb, targetInt, sourceInt, (verbInt) =>
new AddToGraphIndexOperation(this.graphIndex, reverseVerb, targetInt, sourceInt, this.graphWriteGeneration, (verbInt) =>
this.cacheVerbInt(verbInt, reverseId)
)
)
@ -6161,7 +6175,7 @@ export class Brainy<T = any> implements BrainyInterface<T> {
if (verb) {
const { sourceInt, targetInt } = this.resolveVerbEndpointInts(verb)
plan.operations.push(
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt)
new RemoveFromGraphIndexOperation(this.graphIndex, verb, sourceInt, targetInt, this.graphWriteGeneration)
)
}
plan.operations.push(new DeleteVerbMetadataOperation(this.storage, id))

View file

@ -646,9 +646,20 @@ export class GraphAdjacencyIndex implements GraphIndexProvider {
* @param verb - The verb to index (endpoint UUIDs are authoritative).
* @param sourceInt - The source entity's interned int (contract parity).
* @param targetInt - The target entity's interned int (contract parity).
* @param generation - The commit generation (contract parity). The JS index
* keeps a single live adjacency view, not a per-generation edge chain, so
* it ignores this: `db.asOf(g)` graph hops on the open-core path see edges
* as-of-now (the one documented graph time-travel limitation native
* providers thread this into a versioned endpoint store for correctness).
* @returns The interned verb int for `verb.id` (stable for the index lifetime).
*/
async addVerb(verb: GraphVerb, sourceInt: bigint, targetInt: bigint): Promise<bigint> {
async addVerb(
verb: GraphVerb,
sourceInt: bigint,
targetInt: bigint,
generation: bigint
): Promise<bigint> {
void generation // Contract parity — no per-generation chain in the JS index.
await this.ensureInitialized()
return BigInt(await this.indexVerb(verb))
}
@ -703,9 +714,13 @@ export class GraphAdjacencyIndex implements GraphIndexProvider {
* retained so previously returned verb ints stay resolvable via
* {@link verbIntsToIds}.
* @param verbId - The verb's UUID string.
* @param generation - The commit generation (contract parity). The JS index
* tombstones immediately rather than chaining the removal per generation,
* so it ignores this (see {@link addVerb} for the time-travel rationale).
* @returns Resolves once the verb no longer appears in reads.
*/
async removeVerb(verbId: string): Promise<void> {
async removeVerb(verbId: string, generation: bigint): Promise<void> {
void generation // Contract parity — no per-generation chain in the JS index.
await this.ensureInitialized()
// Load verb from cache/storage to get type info

View file

@ -231,16 +231,26 @@ export interface GraphIndexProvider {
* @param verb - The verb to index (endpoint UUIDs + derived `sourceInt`/`targetInt`).
* @param sourceInt - The source entity's interned int.
* @param targetInt - The target entity's interned int.
* @param generation - Brainy's commit generation for this write the same
* watermark the storage layer stamps onto the record. A provider with a
* per-generation edge chain records the edge's existence at this generation
* so `db.asOf(g)` graph hops resolve historically correct endpoints; the
* JS baseline has no such chain and ignores it (graph time-travel is a
* native-provider capability see the consistency-model doc).
* @returns The interned verb int for `verb.id` (feeds Brainy's warm cache).
*/
addVerb(verb: GraphVerb, sourceInt: bigint, targetInt: bigint): Promise<bigint>
addVerb(verb: GraphVerb, sourceInt: bigint, targetInt: bigint, generation: bigint): Promise<bigint>
/**
* @description Remove one verb from the index by its id string. The verb's
* interned int stays reserved (ints are never recycled within a generation).
* @param verbId - The verb's UUID string.
* @param generation - Brainy's commit generation for this removal. A provider
* with a per-generation edge chain tombstones the edge at this generation
* (so it remains visible to `db.asOf(g)` for `g` before the removal); the
* JS baseline removes immediately and ignores it.
* @returns Resolves once the verb no longer appears in reads.
*/
removeVerb(verbId: string): Promise<void>
removeVerb(verbId: string, generation: bigint): Promise<void>
rebuild(): Promise<void>
flush(): Promise<void>

View file

@ -169,6 +169,12 @@ export class RemoveFromMetadataIndexOperation implements Operation {
* shared idMapper (`getOrAssign`) and passes them alongside the verb; the
* provider returns the interned verb int, which is surfaced through the
* optional `onVerbInt` callback so the coordinator can feed its warm cache.
*
* Generation: `generationFn` is resolved at execute time (not construction) so
* the edge is stamped at the transaction's in-flight commit generation which
* the generation store only assigns once the batch begins executing. The same
* generation is reused for the rollback removal, so an add and its undo
* reference one watermark in a provider's per-generation edge chain.
*/
export class AddToGraphIndexOperation implements Operation {
readonly name = 'AddToGraphIndex'
@ -178,6 +184,8 @@ export class AddToGraphIndexOperation implements Operation {
* @param verb - The verb to index (`sourceInt`/`targetInt` mirrored on it).
* @param sourceInt - The source entity's interned int.
* @param targetInt - The target entity's interned int.
* @param generationFn - Resolves the commit generation to stamp this edge at,
* evaluated when the operation executes (see class note).
* @param onVerbInt - Optional hook invoked with the interned verb int
* returned by the provider (feeds the coordinator's verb-int warm cache).
*/
@ -186,18 +194,21 @@ export class AddToGraphIndexOperation implements Operation {
private readonly verb: GraphVerb,
private readonly sourceInt: bigint,
private readonly targetInt: bigint,
private readonly generationFn: () => bigint,
private readonly onVerbInt?: (verbInt: bigint) => void
) {}
async execute(): Promise<RollbackAction> {
// Add verb to graph index
const verbInt = await this.index.addVerb(this.verb, this.sourceInt, this.targetInt)
// Stamp this edge at the in-flight commit generation; reuse it for the
// rollback so add + undo reference the same watermark.
const generation = this.generationFn()
const verbInt = await this.index.addVerb(this.verb, this.sourceInt, this.targetInt, generation)
this.onVerbInt?.(verbInt)
// Return rollback action
return async () => {
// Remove verb from graph index
await this.index.removeVerb(this.verb.id)
await this.index.removeVerb(this.verb.id, generation)
}
}
}
@ -209,8 +220,10 @@ export class AddToGraphIndexOperation implements Operation {
* - Re-add verb to graph index
*
* 8.0 u64 contract: rollback re-adds through `addVerb(verb, sourceInt,
* targetInt)`, so the coordinator resolves the endpoint ints up front
* (while the entity int mappings are guaranteed to still exist).
* targetInt, generation)`, so the coordinator resolves the endpoint ints up
* front (while the entity int mappings are guaranteed to still exist). The
* removal generation is resolved at execute time and reused for the rollback
* re-add, so the round trip references one watermark.
*/
export class RemoveFromGraphIndexOperation implements Operation {
readonly name = 'RemoveFromGraphIndex'
@ -220,22 +233,26 @@ export class RemoveFromGraphIndexOperation implements Operation {
* @param verb - The verb being removed (required for rollback re-add).
* @param sourceInt - The source entity's interned int (rollback re-add).
* @param targetInt - The target entity's interned int (rollback re-add).
* @param generationFn - Resolves the commit generation for this removal,
* evaluated when the operation executes.
*/
constructor(
private readonly index: GraphIndexProvider,
private readonly verb: GraphVerb, // Required for rollback
private readonly sourceInt: bigint,
private readonly targetInt: bigint
private readonly targetInt: bigint,
private readonly generationFn: () => bigint
) {}
async execute(): Promise<RollbackAction> {
// Remove verb from graph index
await this.index.removeVerb(this.verb.id)
// Resolve the removal generation once; reuse it for the rollback re-add.
const generation = this.generationFn()
await this.index.removeVerb(this.verb.id, generation)
// Return rollback action
return async () => {
// Re-add verb with original data
await this.index.addVerb(this.verb, this.sourceInt, this.targetInt)
await this.index.addVerb(this.verb, this.sourceInt, this.targetInt, generation)
}
}
}

View file

@ -64,11 +64,13 @@ describe('GraphAdjacencyIndex — BigInt boundary (JS implementation)', () => {
verb.sourceInt = sourceInt
verb.targetInt = targetInt
const verbInt = await index.addVerb(verb, sourceInt, targetInt)
// The 4th arg is the commit generation — contract parity with native
// providers; the JS index ignores it (no per-generation edge chain).
const verbInt = await index.addVerb(verb, sourceInt, targetInt, 1n)
expect(typeof verbInt).toBe('bigint')
// Re-adding the same verb id returns the SAME interned int (stable).
const verbIntAgain = await index.addVerb(verb, sourceInt, targetInt)
const verbIntAgain = await index.addVerb(verb, sourceInt, targetInt, 1n)
expect(verbIntAgain).toBe(verbInt)
// Both directed verb-int reads surface the int from addVerb.
@ -88,7 +90,7 @@ describe('GraphAdjacencyIndex — BigInt boundary (JS implementation)', () => {
const bInt = BigInt(idMapper.getOrAssign('uuid-b'))
const verb = makeVerb(VERB_UUID_2, 'uuid-a', 'uuid-b')
await index.addVerb(verb, aInt, bInt)
await index.addVerb(verb, aInt, bInt, 1n)
const out = await index.getNeighbors(aInt, { direction: 'out' })
expect(out).toEqual([bInt])
@ -113,7 +115,7 @@ describe('GraphAdjacencyIndex — BigInt boundary (JS implementation)', () => {
const tInt = BigInt(idMapper.getOrAssign('uuid-t'))
const verb = makeVerb(VERB_UUID_3, 'uuid-s', 'uuid-t')
const verbInt = await index.addVerb(verb, sInt, tInt)
const verbInt = await index.addVerb(verb, sInt, tInt, 1n)
// Persist the verb (vector + metadata — getVerb requires both) so
// removeVerb can resolve its type for count updates.
await storage.saveVerb({
@ -129,7 +131,7 @@ describe('GraphAdjacencyIndex — BigInt boundary (JS implementation)', () => {
createdAt: Date.now()
})
await index.removeVerb(verb.id)
await index.removeVerb(verb.id, 2n)
// Removed verb no longer appears in reads…
expect(await index.getVerbIdsBySource(sInt)).toEqual([])

View file

@ -0,0 +1,111 @@
/**
* Generation threading through the graph-index transaction operations.
*
* The graph time-travel contract (AddVerb/RemoveVerb gain a `generation`) is
* load-bearing for native providers: `db.asOf(g)` graph hops resolve historical
* endpoints from a per-generation edge chain the provider stamps at write time.
* Brainy's JS index ignores the value, so a behavioural test against it proves
* nothing these tests use a spy provider to assert the operation layer:
* 1. passes the resolved generation to addVerb/removeVerb,
* 2. resolves the generation at EXECUTE time, not construction (the batch
* generation is only assigned once the commit begins executing), and
* 3. reuses one generation across an operation's forward + rollback halves
* (so an add and its undo reference the same watermark in the chain).
*/
import { describe, it, expect } from 'vitest'
import {
AddToGraphIndexOperation,
RemoveFromGraphIndexOperation
} from '../../../src/transaction/operations/IndexOperations.js'
import type { GraphIndexProvider } from '../../../src/plugin.js'
import type { GraphVerb } from '../../../src/coreTypes.js'
import { VerbType } from '../../../src/types/graphTypes.js'
/** A graph verb with just the fields the operations touch. */
function makeVerb(id: string): GraphVerb {
return {
id,
sourceId: 'src-uuid',
targetId: 'tgt-uuid',
type: VerbType.RelatedTo,
sourceInt: 10n,
targetInt: 20n
} as unknown as GraphVerb
}
/** Records every (method, generation) the operations push to the provider. */
function makeSpyProvider(): {
provider: GraphIndexProvider
calls: Array<{ method: 'addVerb' | 'removeVerb'; generation: bigint; verbId: string }>
} {
const calls: Array<{ method: 'addVerb' | 'removeVerb'; generation: bigint; verbId: string }> = []
const provider = {
async addVerb(verb: GraphVerb, _s: bigint, _t: bigint, generation: bigint): Promise<bigint> {
calls.push({ method: 'addVerb', generation, verbId: verb.id })
return 99n // interned verb int
},
async removeVerb(verbId: string, generation: bigint): Promise<void> {
calls.push({ method: 'removeVerb', generation, verbId })
}
} as unknown as GraphIndexProvider
return { provider, calls }
}
describe('Graph index operations — generation threading', () => {
it('AddToGraphIndexOperation stamps addVerb (and its rollback removeVerb) at the resolved generation', async () => {
const { provider, calls } = makeSpyProvider()
const verb = makeVerb('verb-1')
const op = new AddToGraphIndexOperation(provider, verb, 10n, 20n, () => 7n)
const rollback = await op.execute()
expect(calls).toEqual([{ method: 'addVerb', generation: 7n, verbId: 'verb-1' }])
await rollback()
expect(calls[1]).toEqual({ method: 'removeVerb', generation: 7n, verbId: 'verb-1' })
})
it('RemoveFromGraphIndexOperation stamps removeVerb (and its rollback addVerb) at the resolved generation', async () => {
const { provider, calls } = makeSpyProvider()
const verb = makeVerb('verb-2')
const op = new RemoveFromGraphIndexOperation(provider, verb, 10n, 20n, () => 12n)
const rollback = await op.execute()
expect(calls).toEqual([{ method: 'removeVerb', generation: 12n, verbId: 'verb-2' }])
await rollback()
expect(calls[1]).toEqual({ method: 'addVerb', generation: 12n, verbId: 'verb-2' })
})
it('resolves the generation at EXECUTE time, not at construction', async () => {
// The generation store assigns the batch generation only once the commit
// begins executing — after the operations are built. The thunk must be read
// then, so a value that changes between construction and execute is observed
// at its execute-time value.
const { provider, calls } = makeSpyProvider()
let current = 1n
const op = new AddToGraphIndexOperation(provider, makeVerb('verb-3'), 10n, 20n, () => current)
current = 42n // store assigns the batch generation after the op is built
await op.execute()
expect(calls[0].generation).toBe(42n)
})
it('still surfaces the provider verb int through onVerbInt after the signature change', async () => {
const { provider } = makeSpyProvider()
let seen: bigint | undefined
const op = new AddToGraphIndexOperation(
provider,
makeVerb('verb-4'),
10n,
20n,
() => 5n,
(verbInt) => {
seen = verbInt
}
)
await op.execute()
expect(seen).toBe(99n)
})
})