76 lines
2.5 KiB
JavaScript
76 lines
2.5 KiB
JavaScript
import { Document } from "@langchain/core/documents";
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import { RemoteRetriever, } from "./remote/base.js";
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/**
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* Class responsible for retrieving data from Vespa. It extends the
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* `RemoteRetriever` class and includes methods for creating the JSON body
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* for a query and processing the JSON response from Vespa.
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* @example
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* ```typescript
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* const retriever = new VespaRetriever({
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* url: "https:
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* auth: false,
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* query_body: {
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* yql: "select content from paragraph where userQuery()",
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* hits: 5,
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* ranking: "documentation",
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* locale: "en-us",
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* },
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* content_field: "content",
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* });
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* const result = await retriever.getRelevantDocuments("what is vespa?");
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* ```
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*/
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export class VespaRetriever extends RemoteRetriever {
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static lc_name() {
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return "VespaRetriever";
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}
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constructor(fields) {
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super(fields);
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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", "vespa"]
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});
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Object.defineProperty(this, "query_body", {
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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, "content_field", {
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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.query_body = fields.query_body;
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this.content_field = fields.content_field;
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this.url = `${this.url}/search/?`;
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}
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/**
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* Method that takes a query string as input and returns a JSON object
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* that includes the query and the original `query_body`.
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* @param query The query string to be sent to Vespa.
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* @returns A JSON object that includes the query and the original `query_body`.
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*/
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createJsonBody(query) {
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return {
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...this.query_body,
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query,
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};
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}
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/**
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* Method that processes the JSON response from Vespa into an array of
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* `Document` instances. Each `Document` instance includes the content
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* from the specified `content_field` and the document's ID.
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* @param json The JSON response from Vespa.
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* @returns An array of `Document` instances.
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*/
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processJsonResponse(json) {
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return json.root.children.map((doc) => new Document({
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pageContent: doc.fields[this.content_field],
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metadata: { id: doc.id },
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}));
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}
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}
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