@langchain/community
Version:
Third-party integrations for LangChain.js
209 lines (208 loc) • 7.66 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.FirestoreChatMessageHistory = void 0;
const app_1 = require("firebase-admin/app");
const firestore_1 = require("firebase-admin/firestore");
const chat_history_1 = require("@langchain/core/chat_history");
const messages_1 = require("@langchain/core/messages");
/**
* Class for managing chat message history using Google's Firestore as a
* storage backend. Extends the BaseListChatMessageHistory class.
* @example
* ```typescript
* const chatHistory = new FirestoreChatMessageHistory({
* collectionName: "langchain",
* sessionId: "lc-example",
* userId: "a@example.com",
* config: { projectId: "your-project-id" },
* });
*
* const chain = new ConversationChain({
* llm: new ChatOpenAI(),
* memory: new BufferMemory({ chatHistory }),
* });
*
* const response = await chain.invoke({
* input: "What did I just say my name was?",
* });
* console.log({ response });
* ```
*/
class FirestoreChatMessageHistory extends chat_history_1.BaseListChatMessageHistory {
constructor({ collectionName, collections, docs, sessionId, userId, appIdx = 0, config, }) {
super();
Object.defineProperty(this, "lc_namespace", {
enumerable: true,
configurable: true,
writable: true,
value: ["langchain", "stores", "message", "firestore"]
});
Object.defineProperty(this, "collections", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "docs", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "sessionId", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "userId", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "appIdx", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "config", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "firestoreClient", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "document", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
if (collectionName && collections) {
throw new Error("Can not pass in collectionName and collections. Please use collections only.");
}
if (!collectionName && !collections) {
throw new Error("Must pass in a list of collections. Fields `collectionName` and `collections` are both undefined.");
}
if (collections || docs) {
// This checks that the 'collections' and 'docs' arrays have the same length,
// which means each collection has a corresponding document name. The only exception allowed is
// when there is exactly one collection provided and 'docs' is not defined. In this case, it is
// assumed that the 'sessionId' will be used as the document name for that single collection.
if (!(collections?.length === docs?.length ||
(collections?.length === 1 && !docs))) {
throw new Error("Collections and docs options must have the same length, or collections must have a length of 1 if docs is not defined.");
}
}
this.collections = collections || [collectionName];
this.docs = docs || [sessionId];
this.sessionId = sessionId;
this.userId = userId;
this.document = null;
this.appIdx = appIdx;
if (config)
this.config = config;
try {
this.ensureFirestore();
}
catch (error) {
throw new Error(`Unknown response type`);
}
}
ensureFirestore() {
let app;
// Check if the app is already initialized else get appIdx
if (!(0, app_1.getApps)().length)
app = (0, app_1.initializeApp)(this.config);
else
app = (0, app_1.getApps)()[this.appIdx];
this.firestoreClient = (0, firestore_1.getFirestore)(app);
this.document = this.collections.reduce((acc, collection, index) => acc.collection(collection).doc(this.docs[index]), this.firestoreClient);
}
/**
* Method to retrieve all messages from the Firestore collection
* associated with the current session. Returns an array of BaseMessage
* objects.
* @returns Array of stored messages
*/
async getMessages() {
if (!this.document) {
throw new Error("Document not initialized");
}
const querySnapshot = await this.document
.collection("messages")
.orderBy("createdAt", "asc")
.get()
.catch((err) => {
throw new Error(`Unknown response type: ${err.toString()}`);
});
const response = [];
querySnapshot.forEach((doc) => {
const { type, data } = doc.data();
response.push({ type, data });
});
return (0, messages_1.mapStoredMessagesToChatMessages)(response);
}
/**
* Method to add a new message to the Firestore collection. The message is
* passed as a BaseMessage object.
* @param message The message to be added as a BaseMessage object.
*/
async addMessage(message) {
const messages = (0, messages_1.mapChatMessagesToStoredMessages)([message]);
await this.upsertMessage(messages[0]);
}
async upsertMessage(message) {
if (!this.document) {
throw new Error("Document not initialized");
}
await this.document.set({
id: this.sessionId,
user_id: this.userId,
}, { merge: true });
await this.document
.collection("messages")
.add({
type: message.type,
data: message.data,
createdBy: this.userId,
createdAt: firestore_1.FieldValue.serverTimestamp(),
})
.catch((err) => {
throw new Error(`Unknown response type: ${err.toString()}`);
});
}
/**
* Method to delete all messages from the Firestore collection associated
* with the current session.
*/
async clear() {
if (!this.document) {
throw new Error("Document not initialized");
}
await this.document
.collection("messages")
.get()
.then((querySnapshot) => {
querySnapshot.docs.forEach((snapshot) => {
snapshot.ref.delete().catch((err) => {
throw new Error(`Unknown response type: ${err.toString()}`);
});
});
})
.catch((err) => {
throw new Error(`Unknown response type: ${err.toString()}`);
});
await this.document.delete().catch((err) => {
throw new Error(`Unknown response type: ${err.toString()}`);
});
}
}
exports.FirestoreChatMessageHistory = FirestoreChatMessageHistory;