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@langchain/langgraph

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{"version":3,"file":"stream.cjs","names":["IterableReadableStream","streamControllerPromiseResolver: (\n controller: ReadableStreamDefaultController\n ) => void","streamControllerPromise: Promise<ReadableStreamDefaultController>","result: Record<string, unknown>","cloneTask: Record<string, unknown>","data: unknown"],"sources":["../../src/pregel/stream.ts"],"sourcesContent":["import { IterableReadableStream } from \"@langchain/core/utils/stream\";\nimport type { RunnableConfig } from \"@langchain/core/runnables\";\nimport type { StreamMode, StreamOutputMap } from \"./types.js\";\n\n// [namespace, streamMode, payload]\nexport type StreamChunk = [string[], StreamMode, unknown];\n\ntype StreamCheckpointsOutput<StreamValues> = StreamOutputMap<\n \"checkpoints\",\n false,\n StreamValues,\n unknown,\n string,\n unknown,\n unknown,\n undefined\n>;\n\ntype AnyStreamOutput = StreamOutputMap<\n StreamMode[],\n true,\n unknown,\n unknown,\n string,\n unknown,\n unknown,\n undefined\n>;\n\n/**\n * A wrapper around an IterableReadableStream that allows for aborting the stream when\n * {@link cancel} is called.\n */\nexport class IterableReadableStreamWithAbortSignal<\n T\n> extends IterableReadableStream<T> {\n protected _abortController: AbortController;\n\n protected _innerReader: ReadableStreamDefaultReader<T>;\n\n /**\n * @param readableStream - The stream to wrap.\n * @param abortController - The abort controller to use. Optional. One will be created if not provided.\n */\n constructor(\n readableStream: ReadableStream<T>,\n abortController?: AbortController\n ) {\n const reader = readableStream.getReader();\n const ac = abortController ?? new AbortController();\n super({\n start(controller: ReadableStreamDefaultController<T>) {\n return pump();\n function pump(): Promise<T | undefined> {\n return reader.read().then(({ done, value }) => {\n // When no more data needs to be consumed, close the stream\n if (done) {\n controller.close();\n return;\n }\n // Enqueue the next data chunk into our target stream\n controller.enqueue(value);\n return pump();\n });\n }\n },\n });\n this._abortController = ac;\n this._innerReader = reader;\n }\n\n /**\n * Aborts the stream, abandoning any pending operations in progress. Calling this triggers an\n * {@link AbortSignal} that is propagated to the tasks that are producing the data for this stream.\n * @param reason - The reason for aborting the stream. Optional.\n */\n override async cancel(reason?: unknown) {\n this._abortController.abort(reason);\n this._innerReader.releaseLock();\n }\n\n /**\n * The {@link AbortSignal} for the stream. Aborted when {@link cancel} is called.\n */\n get signal() {\n return this._abortController.signal;\n }\n}\n\nexport class IterableReadableWritableStream extends IterableReadableStream<StreamChunk> {\n modes: Set<StreamMode>;\n\n private controller: ReadableStreamDefaultController;\n\n private passthroughFn?: (chunk: StreamChunk) => void;\n\n private _closed: boolean = false;\n\n get closed() {\n return this._closed;\n }\n\n constructor(params: {\n passthroughFn?: (chunk: StreamChunk) => void;\n modes: Set<StreamMode>;\n }) {\n let streamControllerPromiseResolver: (\n controller: ReadableStreamDefaultController\n ) => void;\n const streamControllerPromise: Promise<ReadableStreamDefaultController> =\n new Promise<ReadableStreamDefaultController>((resolve) => {\n streamControllerPromiseResolver = resolve;\n });\n\n super({\n start: (controller) => {\n streamControllerPromiseResolver!(controller);\n },\n });\n\n // .start() will always be called before the stream can be interacted\n // with anyway\n void streamControllerPromise.then((controller) => {\n this.controller = controller;\n });\n\n this.passthroughFn = params.passthroughFn;\n this.modes = params.modes;\n }\n\n push(chunk: StreamChunk) {\n this.passthroughFn?.(chunk);\n this.controller.enqueue(chunk);\n }\n\n close() {\n try {\n this.controller.close();\n } catch (e) {\n // pass\n } finally {\n this._closed = true;\n }\n }\n\n // eslint-disable-next-line @typescript-eslint/no-explicit-any\n error(e: any) {\n this.controller.error(e);\n }\n}\n\nfunction _stringifyAsDict(obj: unknown) {\n return JSON.stringify(obj, function (key: string | number, value: unknown) {\n const rawValue = this[key];\n if (\n rawValue != null &&\n typeof rawValue === \"object\" &&\n \"toDict\" in rawValue &&\n typeof rawValue.toDict === \"function\"\n ) {\n const { type, data } = rawValue.toDict();\n return { ...data, type };\n }\n\n return value;\n });\n}\n\nfunction _serializeError(error: unknown) {\n // eslint-disable-next-line no-instanceof/no-instanceof\n if (error instanceof Error) {\n return { error: error.name, message: error.message };\n }\n return { error: \"Error\", message: JSON.stringify(error) };\n}\n\nfunction _isRunnableConfig(\n config: unknown\n): config is RunnableConfig & { configurable: Record<string, unknown> } {\n if (typeof config !== \"object\" || config == null) return false;\n return (\n \"configurable\" in config &&\n typeof config.configurable === \"object\" &&\n config.configurable != null\n );\n}\n\nfunction _extractCheckpointFromConfig(\n config: RunnableConfig | null | undefined\n) {\n if (!_isRunnableConfig(config) || !config.configurable.thread_id) {\n return null;\n }\n\n return {\n thread_id: config.configurable.thread_id,\n checkpoint_ns: config.configurable.checkpoint_ns || \"\",\n checkpoint_id: config.configurable.checkpoint_id || null,\n checkpoint_map: config.configurable.checkpoint_map || null,\n };\n}\n\nfunction _serializeConfig(config: unknown) {\n if (_isRunnableConfig(config)) {\n const configurable = Object.fromEntries(\n Object.entries(config.configurable).filter(\n ([key]) => !key.startsWith(\"__\")\n )\n );\n\n const newConfig = { ...config, configurable };\n delete newConfig.callbacks;\n return newConfig;\n }\n\n return config;\n}\n\nfunction _serializeCheckpoint(payload: StreamCheckpointsOutput<unknown>) {\n const result: Record<string, unknown> = {\n ...payload,\n checkpoint: _extractCheckpointFromConfig(payload.config),\n parent_checkpoint: _extractCheckpointFromConfig(payload.parentConfig),\n\n config: _serializeConfig(payload.config),\n parent_config: _serializeConfig(payload.parentConfig),\n\n tasks: payload.tasks.map((task) => {\n if (_isRunnableConfig(task.state)) {\n const checkpoint = _extractCheckpointFromConfig(task.state);\n if (checkpoint != null) {\n const cloneTask: Record<string, unknown> = { ...task, checkpoint };\n delete cloneTask.state;\n return cloneTask;\n }\n }\n\n return task;\n }),\n };\n\n delete result.parentConfig;\n return result;\n}\n\nexport function toEventStream(stream: AsyncGenerator) {\n const encoder = new TextEncoder();\n return new ReadableStream<Uint8Array>({\n async start(controller) {\n const enqueueChunk = (sse: {\n id?: string;\n event: string;\n data: unknown;\n }) => {\n controller.enqueue(\n encoder.encode(\n `event: ${sse.event}\\ndata: ${_stringifyAsDict(sse.data)}\\n\\n`\n )\n );\n };\n\n try {\n for await (const payload of stream) {\n const [ns, mode, chunk] = payload as AnyStreamOutput;\n\n let data: unknown = chunk;\n if (mode === \"debug\") {\n const debugChunk = chunk;\n\n if (debugChunk.type === \"checkpoint\") {\n data = {\n ...debugChunk,\n payload: _serializeCheckpoint(debugChunk.payload),\n };\n }\n }\n\n if (mode === \"checkpoints\") {\n data = _serializeCheckpoint(chunk);\n }\n\n const event = ns?.length ? `${mode}|${ns.join(\"|\")}` : mode;\n enqueueChunk({ event, data });\n }\n } catch (error) {\n enqueueChunk({ event: \"error\", data: _serializeError(error) });\n }\n\n controller.close();\n },\n });\n}\n"],"mappings":";;;;;;;;AAiCA,IAAa,wCAAb,cAEUA,qDAA0B;CAClC,AAAU;CAEV,AAAU;;;;;CAMV,YACE,gBACA,iBACA;EACA,MAAM,SAAS,eAAe;EAC9B,MAAM,KAAK,mBAAmB,IAAI;AAClC,QAAM,EACJ,MAAM,YAAgD;AACpD,UAAO;GACP,SAAS,OAA+B;AACtC,WAAO,OAAO,OAAO,MAAM,EAAE,MAAM,YAAY;AAE7C,SAAI,MAAM;AACR,iBAAW;AACX;;AAGF,gBAAW,QAAQ;AACnB,YAAO;;;;AAKf,OAAK,mBAAmB;AACxB,OAAK,eAAe;;;;;;;CAQtB,MAAe,OAAO,QAAkB;AACtC,OAAK,iBAAiB,MAAM;AAC5B,OAAK,aAAa;;;;;CAMpB,IAAI,SAAS;AACX,SAAO,KAAK,iBAAiB;;;AAIjC,IAAa,iCAAb,cAAoDA,qDAAoC;CACtF;CAEA,AAAQ;CAER,AAAQ;CAER,AAAQ,UAAmB;CAE3B,IAAI,SAAS;AACX,SAAO,KAAK;;CAGd,YAAY,QAGT;EACD,IAAIC;EAGJ,MAAMC,0BACJ,IAAI,SAA0C,YAAY;AACxD,qCAAkC;;AAGtC,QAAM,EACJ,QAAQ,eAAe;AACrB,mCAAiC;;AAMrC,EAAK,wBAAwB,MAAM,eAAe;AAChD,QAAK,aAAa;;AAGpB,OAAK,gBAAgB,OAAO;AAC5B,OAAK,QAAQ,OAAO;;CAGtB,KAAK,OAAoB;AACvB,OAAK,gBAAgB;AACrB,OAAK,WAAW,QAAQ;;CAG1B,QAAQ;AACN,MAAI;AACF,QAAK,WAAW;WACT,GAAG,WAEF;AACR,QAAK,UAAU;;;CAKnB,MAAM,GAAQ;AACZ,OAAK,WAAW,MAAM;;;AAI1B,SAAS,iBAAiB,KAAc;AACtC,QAAO,KAAK,UAAU,KAAK,SAAU,KAAsB,OAAgB;EACzE,MAAM,WAAW,KAAK;AACtB,MACE,YAAY,QACZ,OAAO,aAAa,YACpB,YAAY,YACZ,OAAO,SAAS,WAAW,YAC3B;GACA,MAAM,EAAE,MAAM,SAAS,SAAS;AAChC,UAAO;IAAE,GAAG;IAAM;;;AAGpB,SAAO;;;AAIX,SAAS,gBAAgB,OAAgB;AAEvC,KAAI,iBAAiB,MACnB,QAAO;EAAE,OAAO,MAAM;EAAM,SAAS,MAAM;;AAE7C,QAAO;EAAE,OAAO;EAAS,SAAS,KAAK,UAAU;;;AAGnD,SAAS,kBACP,QACsE;AACtE,KAAI,OAAO,WAAW,YAAY,UAAU,KAAM,QAAO;AACzD,QACE,kBAAkB,UAClB,OAAO,OAAO,iBAAiB,YAC/B,OAAO,gBAAgB;;AAI3B,SAAS,6BACP,QACA;AACA,KAAI,CAAC,kBAAkB,WAAW,CAAC,OAAO,aAAa,UACrD,QAAO;AAGT,QAAO;EACL,WAAW,OAAO,aAAa;EAC/B,eAAe,OAAO,aAAa,iBAAiB;EACpD,eAAe,OAAO,aAAa,iBAAiB;EACpD,gBAAgB,OAAO,aAAa,kBAAkB;;;AAI1D,SAAS,iBAAiB,QAAiB;AACzC,KAAI,kBAAkB,SAAS;EAC7B,MAAM,eAAe,OAAO,YAC1B,OAAO,QAAQ,OAAO,cAAc,QACjC,CAAC,SAAS,CAAC,IAAI,WAAW;EAI/B,MAAM,YAAY;GAAE,GAAG;GAAQ;;AAC/B,SAAO,UAAU;AACjB,SAAO;;AAGT,QAAO;;AAGT,SAAS,qBAAqB,SAA2C;CACvE,MAAMC,SAAkC;EACtC,GAAG;EACH,YAAY,6BAA6B,QAAQ;EACjD,mBAAmB,6BAA6B,QAAQ;EAExD,QAAQ,iBAAiB,QAAQ;EACjC,eAAe,iBAAiB,QAAQ;EAExC,OAAO,QAAQ,MAAM,KAAK,SAAS;AACjC,OAAI,kBAAkB,KAAK,QAAQ;IACjC,MAAM,aAAa,6BAA6B,KAAK;AACrD,QAAI,cAAc,MAAM;KACtB,MAAMC,YAAqC;MAAE,GAAG;MAAM;;AACtD,YAAO,UAAU;AACjB,YAAO;;;AAIX,UAAO;;;AAIX,QAAO,OAAO;AACd,QAAO;;AAGT,SAAgB,cAAc,QAAwB;CACpD,MAAM,UAAU,IAAI;AACpB,QAAO,IAAI,eAA2B,EACpC,MAAM,MAAM,YAAY;EACtB,MAAM,gBAAgB,QAIhB;AACJ,cAAW,QACT,QAAQ,OACN,UAAU,IAAI,MAAM,UAAU,iBAAiB,IAAI,MAAM;;AAK/D,MAAI;AACF,cAAW,MAAM,WAAW,QAAQ;IAClC,MAAM,CAAC,IAAI,MAAM,SAAS;IAE1B,IAAIC,OAAgB;AACpB,QAAI,SAAS,SAAS;KACpB,MAAM,aAAa;AAEnB,SAAI,WAAW,SAAS,aACtB,QAAO;MACL,GAAG;MACH,SAAS,qBAAqB,WAAW;;;AAK/C,QAAI,SAAS,cACX,QAAO,qBAAqB;IAG9B,MAAM,QAAQ,IAAI,SAAS,GAAG,KAAK,GAAG,GAAG,KAAK,SAAS;AACvD,iBAAa;KAAE;KAAO;;;WAEjB,OAAO;AACd,gBAAa;IAAE,OAAO;IAAS,MAAM,gBAAgB;;;AAGvD,aAAW"}