mirror of
https://github.com/hwchase17/langchain
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30e48c9878
Marking as patch since we haven't had releases in between. This just reverting part of a PR from yesterday.
41 lines
1.4 KiB
Python
41 lines
1.4 KiB
Python
import json
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from pathlib import Path
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from typing import List
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from langchain_core.chat_history import (
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BaseChatMessageHistory,
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)
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from langchain_core.messages import BaseMessage, messages_from_dict, messages_to_dict
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class FileChatMessageHistory(BaseChatMessageHistory):
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"""Chat message history that stores history in a local file."""
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def __init__(self, file_path: str) -> None:
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"""Initialize the file path for the chat history.
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Args:
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file_path: The path to the local file to store the chat history.
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"""
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self.file_path = Path(file_path)
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if not self.file_path.exists():
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self.file_path.touch()
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self.file_path.write_text(json.dumps([]))
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@property
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def messages(self) -> List[BaseMessage]: # type: ignore
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"""Retrieve the messages from the local file"""
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items = json.loads(self.file_path.read_text())
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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 the local file"""
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messages = messages_to_dict(self.messages)
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messages.append(messages_to_dict([message])[0])
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self.file_path.write_text(json.dumps(messages))
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def clear(self) -> None:
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"""Clear session memory from the local file"""
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self.file_path.write_text(json.dumps([]))
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