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168e9ed3a5
**Description:** Adds options for configuring MongoDBChatMessageHistory (no breaking changes): - session_id_key: name of the field that stores the session id - history_key: name of the field that stores the chat history - create_index: whether to create an index on the session id field - index_kwargs: additional keyword arguments to pass to the index creation **Discussion:** https://github.com/langchain-ai/langchain/discussions/22918 **Twitter handle:** @userlerueda --------- Co-authored-by: Jib <Jibzade@gmail.com> Co-authored-by: Eugene Yurtsev <eugene@langchain.dev>
101 lines
3.3 KiB
Python
101 lines
3.3 KiB
Python
import json
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import logging
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from typing import Dict, List, Optional
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from langchain_core.chat_history import BaseChatMessageHistory
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from langchain_core.messages import (
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BaseMessage,
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message_to_dict,
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messages_from_dict,
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)
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from pymongo import MongoClient, errors
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logger = logging.getLogger(__name__)
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DEFAULT_DBNAME = "chat_history"
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DEFAULT_COLLECTION_NAME = "message_store"
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DEFAULT_SESSION_ID_KEY = "SessionId"
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DEFAULT_HISTORY_KEY = "History"
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class MongoDBChatMessageHistory(BaseChatMessageHistory):
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"""Chat message history that stores history in MongoDB.
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Args:
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connection_string: connection string to connect to MongoDB
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session_id: arbitrary key that is used to store the messages
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of a single chat session.
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database_name: name of the database to use
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collection_name: name of the collection to use
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session_id_key: name of the field that stores the session id
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history_key: name of the field that stores the chat history
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create_index: whether to create an index on the session id field
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index_kwargs: additional keyword arguments to pass to the index creation
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"""
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def __init__(
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self,
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connection_string: str,
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session_id: str,
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database_name: str = DEFAULT_DBNAME,
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collection_name: str = DEFAULT_COLLECTION_NAME,
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*,
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session_id_key: str = DEFAULT_SESSION_ID_KEY,
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history_key: str = DEFAULT_HISTORY_KEY,
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create_index: bool = True,
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index_kwargs: Optional[Dict] = None,
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):
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self.connection_string = connection_string
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self.session_id = session_id
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self.database_name = database_name
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self.collection_name = collection_name
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self.session_id_key = session_id_key
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self.history_key = history_key
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try:
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self.client: MongoClient = MongoClient(connection_string)
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except errors.ConnectionFailure as error:
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logger.error(error)
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self.db = self.client[database_name]
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self.collection = self.db[collection_name]
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if create_index:
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index_kwargs = index_kwargs or {}
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self.collection.create_index(self.session_id_key, **index_kwargs)
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@property
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def messages(self) -> List[BaseMessage]: # type: ignore
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"""Retrieve the messages from MongoDB"""
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try:
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cursor = self.collection.find({self.session_id_key: self.session_id})
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except errors.OperationFailure as error:
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logger.error(error)
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if cursor:
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items = [json.loads(document[self.history_key]) for document in cursor]
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else:
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items = []
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messages = messages_from_dict(items)
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return messages
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def add_message(self, message: BaseMessage) -> None:
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"""Append the message to the record in MongoDB"""
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try:
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self.collection.insert_one(
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{
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self.session_id_key: self.session_id,
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self.history_key: json.dumps(message_to_dict(message)),
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}
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)
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except errors.WriteError as err:
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logger.error(err)
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def clear(self) -> None:
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"""Clear session memory from MongoDB"""
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try:
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self.collection.delete_many({self.session_id_key: self.session_id})
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except errors.WriteError as err:
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logger.error(err)
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