agsamantha/node_modules/@langchain/community/dist/storage/ioredis.js
2024-10-02 15:15:21 -05:00

156 lines
5.1 KiB
JavaScript

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);
}
}
}
}