90 lines
3 KiB
JavaScript
90 lines
3 KiB
JavaScript
import { BaseRetriever, } from "@langchain/core/retrievers";
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import { createDocumentStoreFromByteStore } from "../storage/encoder_backed.js";
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/**
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* A retriever that retrieves documents from a vector store and a document
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* store. It uses the vector store to find relevant documents based on a
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* query, and then retrieves the full documents from the document store.
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* @example
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* ```typescript
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* const retriever = new MultiVectorRetriever({
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* vectorstore: new FaissStore(),
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* byteStore: new InMemoryStore<Unit8Array>(),
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* idKey: "doc_id",
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* childK: 20,
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* parentK: 5,
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* });
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*
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* const retrieverResult = await retriever.getRelevantDocuments("justice breyer");
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* console.log(retrieverResult[0].pageContent.length);
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* ```
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*/
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export class MultiVectorRetriever extends BaseRetriever {
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static lc_name() {
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return "MultiVectorRetriever";
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}
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constructor(args) {
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super(args);
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Object.defineProperty(this, "lc_namespace", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: ["langchain", "retrievers", "multi_vector"]
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});
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Object.defineProperty(this, "vectorstore", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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Object.defineProperty(this, "docstore", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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Object.defineProperty(this, "idKey", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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Object.defineProperty(this, "childK", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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Object.defineProperty(this, "parentK", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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this.vectorstore = args.vectorstore;
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if (args.byteStore) {
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this.docstore = createDocumentStoreFromByteStore(args.byteStore);
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}
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else if (args.docstore) {
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this.docstore = args.docstore;
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}
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else {
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throw new Error("byteStore and docstore are undefined. Please provide at least one.");
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}
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this.idKey = args.idKey ?? "doc_id";
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this.childK = args.childK;
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this.parentK = args.parentK;
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}
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async _getRelevantDocuments(query) {
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const subDocs = await this.vectorstore.similaritySearch(query, this.childK);
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const ids = [];
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for (const doc of subDocs) {
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if (doc.metadata[this.idKey] && !ids.includes(doc.metadata[this.idKey])) {
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ids.push(doc.metadata[this.idKey]);
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}
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}
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const docs = await this.docstore.mget(ids);
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return docs
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.filter((doc) => doc !== undefined)
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.slice(0, this.parentK);
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}
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}
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