import { BaseStore } from "@langchain/core/stores"; /** * Class that extends the BaseStore class to interact with a Redis * database. It provides methods for getting, setting, and deleting data, * as well as yielding keys from the database. * @example * ```typescript * const store = new RedisByteStore({ client: new Redis({}) }); * await store.mset([ * [ * "message:id:0", * new TextEncoder().encode(JSON.stringify(new AIMessage("ai stuff..."))), * ], * [ * "message:id:1", * new TextEncoder().encode( * JSON.stringify(new HumanMessage("human stuff...")), * ), * ], * ]); * const retrievedMessages = await store.mget(["message:id:0", "message:id:1"]); * console.log(retrievedMessages.map((v) => new TextDecoder().decode(v))); * const yieldedKeys = []; * for await (const key of store.yieldKeys("message:id:")) { * yieldedKeys.push(key); * } * console.log(yieldedKeys); * await store.mdelete(yieldedKeys); * ``` */ export class RedisByteStore extends BaseStore { constructor(fields) { super(fields); Object.defineProperty(this, "lc_namespace", { enumerable: true, configurable: true, writable: true, value: ["langchain", "storage"] }); Object.defineProperty(this, "client", { enumerable: true, configurable: true, writable: true, value: void 0 }); Object.defineProperty(this, "ttl", { enumerable: true, configurable: true, writable: true, value: void 0 }); Object.defineProperty(this, "namespace", { enumerable: true, configurable: true, writable: true, value: void 0 }); Object.defineProperty(this, "yieldKeysScanBatchSize", { enumerable: true, configurable: true, writable: true, value: 1000 }); this.client = fields.client; this.ttl = fields.ttl; this.namespace = fields.namespace; this.yieldKeysScanBatchSize = fields.yieldKeysScanBatchSize ?? this.yieldKeysScanBatchSize; } _getPrefixedKey(key) { if (this.namespace) { const delimiter = "/"; return `${this.namespace}${delimiter}${key}`; } return key; } _getDeprefixedKey(key) { if (this.namespace) { const delimiter = "/"; return key.slice(this.namespace.length + delimiter.length); } return key; } /** * Gets multiple keys from the Redis database. * @param keys Array of keys to be retrieved. * @returns An array of retrieved values. */ async mget(keys) { const prefixedKeys = keys.map(this._getPrefixedKey.bind(this)); const retrievedValues = await this.client.mgetBuffer(prefixedKeys); return retrievedValues.map((value) => { if (!value) { return undefined; } else { return value; } }); } /** * Sets multiple keys in the Redis database. * @param keyValuePairs Array of key-value pairs to be set. * @returns Promise that resolves when all keys have been set. */ async mset(keyValuePairs) { const decoder = new TextDecoder(); const encodedKeyValuePairs = keyValuePairs.map(([key, value]) => [ this._getPrefixedKey(key), decoder.decode(value), ]); const pipeline = this.client.pipeline(); for (const [key, value] of encodedKeyValuePairs) { if (this.ttl) { pipeline.set(key, value, "EX", this.ttl); } else { pipeline.set(key, value); } } await pipeline.exec(); } /** * Deletes multiple keys from the Redis database. * @param keys Array of keys to be deleted. * @returns Promise that resolves when all keys have been deleted. */ async mdelete(keys) { await this.client.del(...keys.map(this._getPrefixedKey.bind(this))); } /** * Yields keys from the Redis database. * @param prefix Optional prefix to filter the keys. * @returns An AsyncGenerator that yields keys from the Redis database. */ async *yieldKeys(prefix) { let pattern; if (prefix) { const wildcardPrefix = prefix.endsWith("*") ? prefix : `${prefix}*`; pattern = this._getPrefixedKey(wildcardPrefix); } else { pattern = this._getPrefixedKey("*"); } let [cursor, batch] = await this.client.scan(0, "MATCH", pattern, "COUNT", this.yieldKeysScanBatchSize); for (const key of batch) { yield this._getDeprefixedKey(key); } while (cursor !== "0") { [cursor, batch] = await this.client.scan(cursor, "MATCH", pattern, "COUNT", this.yieldKeysScanBatchSize); for (const key of batch) { yield this._getDeprefixedKey(key); } } } }