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Date.now;\n\t}\n\n\tasync commit(writes: Write[], _context: Context): Promise<CommitResult> {\n\t\tif (this.state !== \"open\") throw new Error(\"MemoryStorage is closed\");\n\t\tconst result = this.commitQueue.then(() => {\n\t\t\tconst prepared = this.storageState.prepareCommit(writes, this.now());\n\t\t\tconst stats = this.storageState.applyValidated(prepared.writes);\n\t\t\treturn { ...prepared.result, stats };\n\t\t});\n\t\tthis.commitQueue = result.then(\n\t\t\t() => undefined,\n\t\t\t() => undefined,\n\t\t);\n\t\treturn result;\n\t}\n\n\tgetEntries(ids: string[], _context: Context): Promise<Map<string, Entry>> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\treturn Promise.resolve(this.storageState.getEntries(ids));\n\t}\n\n\tgetValue<T>(address: Value<T>, _context: Context): Promise<StoredValue<T> | undefined> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\treturn Promise.resolve(this.storageState.getValue(address));\n\t}\n\n\tscanValues<T>(prefix: Value<T>, _context: Context): Promise<StoredValue<T>[]> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\treturn Promise.resolve(this.storageState.scanValues(prefix));\n\t}\n\n\tasync readList<T>(\n\t\taddress: ValueList<T>,\n\t\toptions: ListReadOptions | undefined,\n\t\t_context: Context,\n\t): Promise<ListElement<T>[]> {\n\t\tif (this.state !== \"open\") throw new Error(\"MemoryStorage is closed\");\n\t\treturn this.storageState.readList(address, options);\n\t}\n\n\tasync scanBranch(query: StorageBranchScan, _context: Context): Promise<Entry[]> {\n\t\tif (this.state !== \"open\") throw new Error(\"MemoryStorage is closed\");\n\t\treturn this.storageState.scanBranch(query);\n\t}\n\n\tasync scanBranchStructure(query: StorageBranchScan, _context: Context): Promise<EntryStructure[]> {\n\t\tif (this.state !== \"open\") throw new Error(\"MemoryStorage is closed\");\n\t\treturn this.storageState.scanBranchStructure(query);\n\t}\n\n\tscanEntries(query: EntryScan, _context: Context): Promise<Entry[]> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\treturn Promise.resolve(this.storageState.scanEntries(query));\n\t}\n\n\tscanUsage(query: UsageScan, _context: Context): Promise<UsageRow[]> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\treturn Promise.resolve(this.storageState.scanUsage(query));\n\t}\n\n\tgetStats(_context: Context): Promise<SessionStats> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\treturn Promise.resolve(this.storageState.getStats());\n\t}\n\n\t/** Capture the state needed to fork at one serialized boundary between commits. */\n\tcaptureForkSource(_context: Context): Promise<ForkSourceSnapshot> {\n\t\tif (this.state !== \"open\") return Promise.reject(new Error(\"MemoryStorage is closed\"));\n\t\tconst result = this.commitQueue.then(() => this.storageState.snapshotEntriesAndValues());\n\t\tthis.commitQueue = result.then(\n\t\t\t() => undefined,\n\t\t\t() => undefined,\n\t\t);\n\t\treturn result;\n\t}\n\n\tclose(_context: Context): Promise<void> {\n\t\tif (this.closePromise !== undefined) return this.closePromise;\n\t\tthis.state = \"closing\";\n\t\tthis.closePromise = this.commitQueue.then(() => {\n\t\t\tthis.state = \"closed\";\n\t\t});\n\t\treturn this.closePromise;\n\t}\n\n\tstatic fromSnapshot(options: MemoryStorageOptions, snapshot: ForkDestinationSnapshot): MemoryStorage {\n\t\tconst storage = new MemoryStorage(options);\n\t\tconst writes = forkSnapshotWrites(snapshot);\n\t\tstorage.storageState.validateCommitted(writes);\n\t\tstorage.storageState.applyValidated(writes);\n\t\treturn storage;\n\t}\n}\n\nconst MEMORY_STORAGE_VERSION = 1;\n\ninterface MemorySessionRecord {\n\tmetadata: SessionMetadata;\n\tstorage: MemoryStorage;\n\tsession: StorageBackedSession;\n\topen: boolean;\n}\n\nclass MemorySessionFacade implements Session {\n\treadonly metadata: SessionMetadata;\n\treadonly idGenerator: IdGenerator;\n\tprivate readonly session: StorageBackedSession;\n\tprivate readonly onClose: () => void;\n\tprivate readonly admitted = new Set<Promise<unknown>>();\n\tprivate readonly closedError = new Error(\"Session is closed\");\n\tprivate state: \"open\" | \"closing\" | \"closed\" = \"open\";\n\tprivate closePromise: Promise<void> | undefined;\n\n\tconstructor(session: StorageBackedSession, onClose: () => void) {\n\t\tthis.session = session;\n\t\tthis.metadata = session.metadata;\n\t\tthis.idGenerator = session.idGenerator;\n\t\tthis.onClose = onClose;\n\t}\n\n\tasync beginMutation(context: Context): Promise<SessionMutation> {\n\t\tlet resolveFinished!: () => void;\n\t\tconst finished = new Promise<void>((resolve) => {\n\t\t\tresolveFinished = resolve;\n\t\t});\n\t\tthis.admitted.add(finished);\n\t\tlet source: SessionMutation;\n\t\ttry {\n\t\t\tsource = await this.admit(() => this.session.beginMutation(context));\n\t\t} catch (error) {\n\t\t\tthis.admitted.delete(finished);\n\t\t\tresolveFinished();\n\t\t\tthrow error;\n\t\t}\n\t\tif (this.state !== \"open\") {\n\t\t\tawait source.end(context);\n\t\t\tthis.admitted.delete(finished);\n\t\t\tresolveFinished();\n\t\t\tthrow this.closedError;\n\t\t}\n\t\tlet ended = false;\n\t\treturn {\n\t\t\tcommit: (writes, commitContext) => source.commit(writes, commitContext),\n\t\t\tend: async (endContext) => {\n\t\t\t\ttry {\n\t\t\t\t\tawait source.end(endContext);\n\t\t\t\t} finally {\n\t\t\t\t\tif (!ended) {\n\t\t\t\t\t\tended = true;\n\t\t\t\t\t\tthis.admitted.delete(finished);\n\t\t\t\t\t\tresolveFinished();\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t},\n\t\t\tgetEntries: (ids, readContext) => source.getEntries(ids, readContext),\n\t\t\tgetStats: (readContext) => source.getStats(readContext),\n\t\t\tgetValue: (address, readContext) => source.getValue(address, readContext),\n\t\t\tscanValues: (prefix, readContext) => source.scanValues(prefix, readContext),\n\t\t\treadList: (address, options, readContext) => source.readList(address, options, readContext),\n\t\t\tscanBranch: (query, readContext) => source.scanBranch(query, readContext),\n\t\t};\n\t}\n\n\tmutate<T>(mutation: SessionMutationCallback<T>, context: Context): Promise<T> {\n\t\treturn this.admit(() =>\n\t\t\tthis.session.mutate((mutator, mutationContext) => {\n\t\t\t\tif (this.state !== \"open\") throw this.closedError;\n\t\t\t\treturn mutation(mutator, mutationContext);\n\t\t\t}, context),\n\t\t);\n\t}\n\n\tgetEntries(ids: string[], context: Context): Promise<Map<string, Entry>> {\n\t\treturn this.admit(() => this.session.getEntries(ids, context));\n\t}\n\n\tgetEntry(id: string, context: Context): Promise<Entry | undefined> {\n\t\treturn this.admit(() => this.session.getEntry(id, context));\n\t}\n\n\tgetValue<T>(address: Value<T>, context: Context): Promise<StoredValue<T> | undefined> {\n\t\treturn this.admit(() => this.session.getValue(address, context));\n\t}\n\n\tscanValues<T>(prefix: Value<T>, context: Context): Promise<StoredValue<T>[]> {\n\t\treturn this.admit(() => this.session.scanValues(prefix, context));\n\t}\n\n\treadList<T>(\n\t\taddress: ValueList<T>,\n\t\toptions: ListReadOptions | undefined,\n\t\tcontext: Context,\n\t): Promise<ListElement<T>[]> {\n\t\treturn this.admit(() => this.session.readList(address, options, context));\n\t}\n\n\tscanBranch(query: StorageBranchScan, context: Context): Promise<Entry[]> {\n\t\treturn this.admit(() => this.session.scanBranch(query, context));\n\t}\n\n\tgetStats(context: Context): Promise<SessionStats> {\n\t\treturn this.admit(() => this.session.getStats(context));\n\t}\n\n\tgetName(context: Context): Promise<string | undefined> {\n\t\treturn this.admit(() => this.session.getName(context));\n\t}\n\n\tgetLabel(targetId: string, context: Context): Promise<string | undefined> {\n\t\treturn this.admit(() => this.session.getLabel(targetId, context));\n\t}\n\n\tfindEntries(query: EntryQuery | undefined, context: Context): Promise<Entry[]> {\n\t\treturn this.admit(() => this.session.findEntries(query, context));\n\t}\n\n\tfindEntry(query: EntryQuery | undefined, context: Context): Promise<Entry | undefined> {\n\t\treturn this.admit(() => this.session.findEntry(query, context));\n\t}\n\n\tasync branch(name: string, context: Context): Promise<Branch | undefined> {\n\t\tconst branch = await this.admit(() => this.session.branch(name, context));\n\t\treturn branch === undefined ? undefined : this.wrapBranch(branch);\n\t}\n\n\tasync createBranch(name: string, at: string | null, context: Context): Promise<Branch> {\n\t\treturn this.wrapBranch(await this.admit(() => this.session.createBranch(name, at, context)));\n\t}\n\n\tsetValue<T>(address: Value<T>, next: NoInfer<T>, context: Context): Promise<void> {\n\t\treturn this.admit(() => this.session.setValue(address, next, context));\n\t}\n\n\tdeleteValue<T>(address: Value<T>, context: Context): Promise<void> {\n\t\treturn this.admit(() => this.session.deleteValue(address, context));\n\t}\n\n\tappendList<T>(address: ValueList<T>, element: NoInfer<T>, context: Context): Promise<void> {\n\t\treturn this.admit(() => this.session.appendList(address, element, context));\n\t}\n\n\tdeleteList<T>(address: ValueList<T>, context: Context): Promise<void> {\n\t\treturn this.admit(() => this.session.deleteList(address, context));\n\t}\n\n\tsetName(name: string | undefined, context: Context): Promise<void> {\n\t\treturn this.admit(() => this.session.setName(name, context));\n\t}\n\n\tsetLabel(targetId: string, label: string | undefined, context: Context): Promise<void> {\n\t\treturn this.admit(() => this.session.setLabel(targetId, label, context));\n\t}\n\n\tclose(_context: Context): Promise<void> {\n\t\tif (this.closePromise !== undefined) return this.closePromise;\n\t\tthis.state = \"closing\";\n\t\tthis.closePromise = Promise.allSettled([...this.admitted]).then(() => {\n\t\t\tthis.state = \"closed\";\n\t\t\tthis.onClose();\n\t\t});\n\t\treturn this.closePromise;\n\t}\n\n\tprivate wrapBranch(branch: Branch): Branch {\n\t\treturn {\n\t\t\tname: branch.name,\n\t\t\tgetTipId: (context) => this.admit(() => branch.getTipId(context)),\n\t\t\tfindEntries: (query, context) => this.admit(() => branch.findEntries(query, context)),\n\t\t\tfindEntry: (query, context) => this.admit(() => branch.findEntry(query, context)),\n\t\t\tappendMessage: (message, context) => this.admit(() => branch.appendMessage(message, context)),\n\t\t\tappendCustomEntry: (customType, data, context) =>\n\t\t\t\tthis.admit(() => branch.appendCustomEntry(customType, data, context)),\n\t\t};\n\t}\n\n\tprivate admit<T>(operation: () => Promise<T>): Promise<T> {\n\t\tif (this.state !== \"open\") return Promise.reject(this.closedError);\n\t\tlet result: Promise<T>;\n\t\ttry {\n\t\t\tresult = operation();\n\t\t} catch (error) {\n\t\t\tresult = Promise.reject(error);\n\t\t}\n\t\tthis.admitted.add(result);\n\t\tvoid result.then(\n\t\t\t() => this.admitted.delete(result),\n\t\t\t() => this.admitted.delete(result),\n\t\t);\n\t\treturn result;\n\t}\n}\n\nexport class MemorySessionRepo implements SessionRepo {\n\tprivate readonly now: () => number;\n\tprivate readonly sessions = new Map<string, MemorySessionRecord>();\n\tprivate readonly pendingIds = new Set<string>();\n\tprivate closed = false;\n\tprivate closePromise: Promise<void> | undefined;\n\n\tconstructor(options: MemorySessionRepoOptions = {}) {\n\t\tthis.now = options.now ?? Date.now;\n\t}\n\n\tasync create(options: SessionCreateOptions, context: Context): Promise<Session> {\n\t\tthis.assertOpen();\n\t\tconst createdAt = this.now();\n\t\tconst id = options.id ?? uuidv7(createdAt);\n\t\tthis.reserveId(id);\n\t\tconst metadata: SessionMetadata = {\n\t\t\tid,\n\t\t\tcreatedAt,\n\t\t\tstorageVersion: MEMORY_STORAGE_VERSION,\n\t\t\t...(options.parentSessionId === undefined ? {} : { parentSessionId: options.parentSessionId }),\n\t\t};\n\t\tconst storage = new MemoryStorage({ now: this.now });\n\t\tconst session = new StorageBackedSession(metadata, storage);\n\t\ttry {\n\t\t\tconst record: MemorySessionRecord = {\n\t\t\t\tmetadata,\n\t\t\t\tstorage,\n\t\t\t\tsession,\n\t\t\t\topen: true,\n\t\t\t};\n\t\t\tthis.sessions.set(id, record);\n\t\t\treturn this.openRecord(record);\n\t\t} catch (error) {\n\t\t\tawait session.close(context);\n\t\t\tthrow error;\n\t\t} finally {\n\t\t\tthis.pendingIds.delete(id);\n\t\t}\n\t}\n\n\topen(metadata: SessionMetadata, _context: Context): Promise<Session> {\n\t\t// Memory sessions are always created at the current storage version, so\n\t\t// persistent-backend version gating does not apply here.\n\t\tthis.assertOpen();\n\t\tconst record = this.sessions.get(metadata.id);\n\t\tif (record === undefined) return Promise.reject(new Error(`Unknown session: ${metadata.id}`));\n\t\tif (record.open) return Promise.reject(new Error(`Session is already open: ${metadata.id}`));\n\t\trecord.open = true;\n\t\treturn Promise.resolve(this.openRecord(record));\n\t}\n\n\tlist(_options: undefined, _context: Context): Promise<SessionMetadata[]> {\n\t\tthis.assertOpen();\n\t\treturn Promise.resolve([...this.sessions.values()].map(({ metadata }) => metadata));\n\t}\n\n\tasync delete(metadata: SessionMetadata, context: Context): Promise<void> {\n\t\tthis.assertOpen();\n\t\tconst record = this.sessions.get(metadata.id);\n\t\tif (record === undefined) throw new Error(`Unknown session: ${metadata.id}`);\n\t\tif (record.open) throw new Error(`Session is open: ${metadata.id}`);\n\t\tawait record.session.close(context);\n\t\tthis.sessions.delete(metadata.id);\n\t}\n\n\tasync fork(source: SessionMetadata, options: ForkOptions, context: Context): Promise<Session> {\n\t\tthis.assertOpen();\n\t\tconst sourceRecord = this.sessions.get(source.id);\n\t\tif (sourceRecord === undefined) throw new Error(`Unknown session: ${source.id}`);\n\t\tconst createdAt = this.now();\n\t\tconst id = options.id ?? uuidv7(createdAt);\n\t\tthis.reserveId(id);\n\n\t\ttry {\n\t\t\tconst snapshot = createForkSnapshot(await sourceRecord.storage.captureForkSource(context), options);\n\t\t\tconst storage = MemoryStorage.fromSnapshot({ now: this.now }, snapshot);\n\t\t\tconst metadata: SessionMetadata = {\n\t\t\t\tid,\n\t\t\t\tcreatedAt,\n\t\t\t\tstorageVersion: MEMORY_STORAGE_VERSION,\n\t\t\t\tparentSessionId: sourceRecord.metadata.id,\n\t\t\t};\n\t\t\tconst session = new StorageBackedSession(metadata, storage);\n\t\t\tconst record: MemorySessionRecord = {\n\t\t\t\tmetadata,\n\t\t\t\tstorage,\n\t\t\t\tsession,\n\t\t\t\topen: true,\n\t\t\t};\n\t\t\tthis.sessions.set(id, record);\n\t\t\treturn this.openRecord(record);\n\t\t} finally {\n\t\t\tthis.pendingIds.delete(id);\n\t\t}\n\t}\n\n\tclose(context: Context): Promise<void> {\n\t\tif (this.closePromise !== undefined) return this.closePromise;\n\t\tthis.closed = true;\n\t\tthis.closePromise = Promise.all([...this.sessions.values()].map(({ session }) => session.close(context))).then(\n\t\t\t() => undefined,\n\t\t);\n\t\treturn this.closePromise;\n\t}\n\n\tprivate openRecord(record: MemorySessionRecord): Session {\n\t\treturn new MemorySessionFacade(record.session, () => {\n\t\t\trecord.open = false;\n\t\t});\n\t}\n\n\tprivate reserveId(id: string): void {\n\t\tif (this.sessions.has(id) || this.pendingIds.has(id)) throw new Error(`Session already exists: ${id}`);\n\t\tthis.pendingIds.add(id);\n\t}\n\n\tprivate assertOpen(): void {\n\t\tif (this.closed) throw new Error(\"MemorySessionRepo is closed\");\n\t}\n}\n"]}