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54 lines
1.5 KiB
Python
54 lines
1.5 KiB
Python
import json
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import logging
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from pathlib import Path
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from typing import List
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from langchain.schema import (
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AIMessage,
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BaseChatMessageHistory,
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BaseMessage,
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HumanMessage,
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messages_from_dict,
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messages_to_dict,
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)
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logger = logging.getLogger(__name__)
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class FileChatMessageHistory(BaseChatMessageHistory):
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"""
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Chat message history that stores history in a local file.
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Args:
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file_path: path of the local file to store the messages.
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"""
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def __init__(self, file_path: str):
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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_user_message(self, message: str) -> None:
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self.append(HumanMessage(content=message))
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def add_ai_message(self, message: str) -> None:
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self.append(AIMessage(content=message))
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def append(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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