@langchain/langgraph/dist/stream/transformers/subgraphs.cjs.map

LangGraph

{"version":3,"file":"subgraphs.cjs","names":["hasPrefix","nsKey"],"sources":["../../../src/stream/transformers/subgraphs.ts"],"sourcesContent":["/**\n * SubgraphDiscoveryTransformer - materializes a {@link StreamHandle} for\n * each newly observed top-level subgraph namespace and announces it on\n * the mux's shared {@link StreamMux._discoveries} channel.\n *\n * Previously this work was inlined in {@link StreamMux.push}.  Extracting\n * it into a transformer aligns discovery with the rest of the stream\n * architecture (lifecycle, values, messages are all transformers),\n * isolates the factory wiring, and makes discovery behavior\n * independently testable.\n *\n * The transformer also owns the read-side of discovery: it exposes an\n * `AsyncIterable<TStream>` projection (`subgraphs`) scoped to the root\n * namespace, and a {@link filterSubgraphHandles} helper that callers\n * can use to scope the same channel to any descendant namespace.  This\n * lets `GraphRunStream` drop its bespoke `subscribeSubgraphs`\n * delegation and surface child streams via the standard native\n * projection pattern.\n *\n * Only first-level namespace segments are announced.  Deeper segments\n * (e.g. `[\"researcher:uuid\", \"tools:uuid\"]`) are internal Pregel\n * checkpoint namespaces for nodes inside a subgraph and should not\n * appear as user-facing `SubgraphRunStream` instances; the mux still\n * resolves their values via its own `#streamMap` when registered\n * elsewhere.\n */\n\nimport { hasPrefix, nsKey } from \"../mux.js\";\nimport type { StreamHandle, StreamMux, SubgraphDiscovery } from \"../mux.js\";\nimport type {\n  Namespace,\n  NativeStreamTransformer,\n  ProtocolEvent,\n} from \"../types.js\";\nimport type { StreamChannel } from \"../stream-channel.js\";\n\n/**\n * Projection returned by {@link createSubgraphDiscoveryTransformer}.\n *\n * @typeParam TStream - Concrete stream handle type produced by the\n *   configured factory (e.g. `SubgraphRunStream`).\n */\nexport interface SubgraphDiscoveryProjection<\n  TStream extends StreamHandle = StreamHandle,\n> {\n  /**\n   * Shared discovery channel on the mux.  The transformer writes to it so\n   * the channel's lifetime stays tied to the mux (closed on `mux.close()`\n   * / failed on `mux.fail()`).  The underscore prefix signals internal\n   * wiring: consumers should iterate {@link subgraphs} instead.\n   */\n  _discoveries: StreamChannel<SubgraphDiscovery>;\n\n  /**\n   * Async iterable of direct child stream handles of the root\n   * namespace.  Wired onto `GraphRunStream.subgraphs` during root\n   * stream construction.  For descendant namespaces, use\n   * {@link filterSubgraphHandles} to scope the same log.\n   */\n  subgraphs: AsyncIterable<TStream>;\n}\n\n/**\n * Configuration for {@link createSubgraphDiscoveryTransformer}.\n */\nexport interface SubgraphDiscoveryTransformerOptions<\n  TStream extends StreamHandle = StreamHandle,\n> {\n  /**\n   * Factory invoked once per newly observed top-level namespace.\n   *\n   * Receives the discovery-channel and event-channel offsets so the resulting\n   * stream can iterate only events arriving after the namespace was\n   * first seen (no retroactive replay).\n   *\n   * @param path - The single-segment top-level namespace.\n   * @param discoveryStart - Current size of the mux discovery log.\n   * @param eventStart - Current size of the mux event log.\n   * @returns A stream handle registered with the mux for values/error\n   *   resolution on close/fail.\n   */\n  createStream: (\n    path: Namespace,\n    discoveryStart: number,\n    eventStart: number\n  ) => TStream;\n}\n\n/**\n * Filter a {@link SubgraphDiscovery} channel to only the direct children\n * of a given namespace.\n *\n * Returns an `AsyncIterable` whose iterator yields stream handles for\n * discoveries whose namespace is exactly one segment deeper than\n * {@link path} and shares it as a prefix.  Iteration begins at\n * {@link startAt} (so each caller picks up only discoveries added\n * after its construction) and terminates when the underlying log\n * closes or fails.\n *\n * @typeParam TStream - Concrete stream type recorded in the log.\n *   Callers may cast if the log was populated by a specific factory.\n * @param log - The shared discovery channel (`mux._discoveries`).\n * @param path - Parent namespace whose direct children should be\n *   yielded.\n * @param startAt - Zero-based index into the discovery log to begin\n *   from.\n * @returns An async iterable of stream handles.\n */\nexport function filterSubgraphHandles<\n  TStream extends StreamHandle = StreamHandle,\n>(\n  log: StreamChannel<SubgraphDiscovery>,\n  path: Namespace,\n  startAt = 0\n): AsyncIterable<TStream> {\n  const targetDepth = path.length + 1;\n  return {\n    [Symbol.asyncIterator](): AsyncIterator<TStream> {\n      const base = log.iterate(startAt);\n      return {\n        async next(): Promise<IteratorResult<TStream>> {\n          // eslint-disable-next-line no-constant-condition\n          while (true) {\n            const result = await base.next();\n            if (result.done) {\n              return { value: undefined as unknown as TStream, done: true };\n            }\n            const { ns, stream } = result.value;\n            if (ns.length === targetDepth && hasPrefix(ns, path)) {\n              return { value: stream as TStream, done: false };\n            }\n          }\n        },\n      };\n    },\n  };\n}\n\n/**\n * Create the subgraph discovery transformer.\n *\n * Registering this transformer against a mux replaces the legacy\n * inline behavior that previously lived in {@link StreamMux.push}.\n * The mux no longer knows about the subgraph factory: instead, this\n * transformer is the single component that materializes stream\n * handles and announces them on `_discoveries`.\n *\n * Marked as a {@link NativeStreamTransformer} so the projection is\n * treated as internal wiring (not merged into `run.extensions` and\n * not auto-forwarded via {@link StreamMux.wireChannels}).\n *\n * @typeParam TStream - Concrete stream handle type produced by\n *   {@link SubgraphDiscoveryTransformerOptions.createStream}.\n *   Defaults to the base {@link StreamHandle} interface.\n * @param mux - The mux whose `_discoveries` log should receive\n *   discovery entries and whose `register` will be called for each\n *   new stream handle.\n * @param options - Factory and related wiring.\n * @returns A native transformer that populates\n *   {@link StreamMux._discoveries} and exposes a root-scoped\n *   `subgraphs` iterable via its projection.\n */\nexport function createSubgraphDiscoveryTransformer<\n  TStream extends StreamHandle = StreamHandle,\n>(\n  mux: StreamMux,\n  options: SubgraphDiscoveryTransformerOptions<TStream>\n): NativeStreamTransformer<SubgraphDiscoveryProjection<TStream>> {\n  const { createStream } = options;\n  const seen = new Set<string>();\n\n  return {\n    __native: true,\n\n    init() {\n      return {\n        _discoveries: mux._discoveries,\n        subgraphs: filterSubgraphHandles<TStream>(mux._discoveries, [], 0),\n      };\n    },\n\n    process(event: ProtocolEvent): boolean {\n      const ns = event.params.namespace;\n      if (ns.length === 0) return true;\n\n      const topNs = ns.slice(0, 1);\n      const topKey = nsKey(topNs);\n      if (seen.has(topKey)) return true;\n      seen.add(topKey);\n\n      const stream = createStream(\n        topNs,\n        mux._discoveries.size,\n        mux._events.size\n      );\n      mux.register(topNs, stream);\n      mux._discoveries.push({ ns: topNs, stream });\n      return true;\n    },\n  };\n}\n"],"mappings":";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AA4GA,SAAgB,sBAGd,KACA,MACA,UAAU,GACc;CACxB,MAAM,cAAc,KAAK,SAAS;AAClC,QAAO,EACL,CAAC,OAAO,iBAAyC;EAC/C,MAAM,OAAO,IAAI,QAAQ,QAAQ;AACjC,SAAO,EACL,MAAM,OAAyC;AAE7C,UAAO,MAAM;IACX,MAAM,SAAS,MAAM,KAAK,MAAM;AAChC,QAAI,OAAO,KACT,QAAO;KAAE,OAAO,KAAA;KAAiC,MAAM;KAAM;IAE/D,MAAM,EAAE,IAAI,WAAW,OAAO;AAC9B,QAAI,GAAG,WAAW,eAAeA,YAAAA,UAAU,IAAI,KAAK,CAClD,QAAO;KAAE,OAAO;KAAmB,MAAM;KAAO;;KAIvD;IAEJ;;;;;;;;;;;;;;;;;;;;;;;;;;AA2BH,SAAgB,mCAGd,KACA,SAC+D;CAC/D,MAAM,EAAE,iBAAiB;CACzB,MAAM,uBAAO,IAAI,KAAa;AAE9B,QAAO;EACL,UAAU;EAEV,OAAO;AACL,UAAO;IACL,cAAc,IAAI;IAClB,WAAW,sBAA+B,IAAI,cAAc,EAAE,EAAE,EAAE;IACnE;;EAGH,QAAQ,OAA+B;GACrC,MAAM,KAAK,MAAM,OAAO;AACxB,OAAI,GAAG,WAAW,EAAG,QAAO;GAE5B,MAAM,QAAQ,GAAG,MAAM,GAAG,EAAE;GAC5B,MAAM,SAASC,YAAAA,MAAM,MAAM;AAC3B,OAAI,KAAK,IAAI,OAAO,CAAE,QAAO;AAC7B,QAAK,IAAI,OAAO;GAEhB,MAAM,SAAS,aACb,OACA,IAAI,aAAa,MACjB,IAAI,QAAQ,KACb;AACD,OAAI,SAAS,OAAO,OAAO;AAC3B,OAAI,aAAa,KAAK;IAAE,IAAI;IAAO;IAAQ,CAAC;AAC5C,UAAO;;EAEV"}