letta-server/memgpt/persistence_manager.py

from abc import ABC, abstractmethod
from datetime import datetime
from typing import List

from memgpt.memory import BaseRecallMemory, EmbeddingArchivalMemory
from memgpt.schemas.agent import AgentState
from memgpt.schemas.memory import Memory
from memgpt.schemas.message import Message
from memgpt.utils import printd


def parse_formatted_time(formatted_time: str):
    # parse times returned by memgpt.utils.get_formatted_time()
    try:
        return datetime.strptime(formatted_time.strip(), "%Y-%m-%d %I:%M:%S %p %Z%z")
    except:
        return datetime.strptime(formatted_time.strip(), "%Y-%m-%d %I:%M:%S %p")


class PersistenceManager(ABC):
    @abstractmethod
    def trim_messages(self, num):
        pass

    @abstractmethod
    def prepend_to_messages(self, added_messages):
        pass

    @abstractmethod
    def append_to_messages(self, added_messages):
        pass

    @abstractmethod
    def swap_system_message(self, new_system_message):
        pass

    @abstractmethod
    def update_memory(self, new_memory):
        pass


class LocalStateManager(PersistenceManager):
    """In-memory state manager has nothing to manage, all agents are held in-memory"""

    recall_memory_cls = BaseRecallMemory
    archival_memory_cls = EmbeddingArchivalMemory

    def __init__(self, agent_state: AgentState):
        # Memory held in-state useful for debugging stateful versions
        self.memory = agent_state.memory
        # self.messages = []  # current in-context messages
        # self.all_messages = [] # all messages seen in current session (needed if lazily synchronizing state with DB)
        self.archival_memory = EmbeddingArchivalMemory(agent_state)
        self.recall_memory = BaseRecallMemory(agent_state)
        # self.agent_state = agent_state

    def save(self):
        """Ensure storage connectors save data"""
        self.archival_memory.save()
        self.recall_memory.save()

    '''
    def json_to_message(self, message_json) -> Message:
        """Convert agent message JSON into Message object"""

        # get message
        if "message" in message_json:
            message = message_json["message"]
        else:
            message = message_json

        # get timestamp
        if "timestamp" in message_json:
            timestamp = parse_formatted_time(message_json["timestamp"])
        else:
            timestamp = get_local_time()

        # TODO: change this when we fully migrate to tool calls API
        if "function_call" in message:
            tool_calls = [
                ToolCall(
                    id=message["tool_call_id"],
                    tool_call_type="function",
                    function={
                        "name": message["function_call"]["name"],
                        "arguments": message["function_call"]["arguments"],
                    },
                )
            ]
            printd(f"Saving tool calls {[vars(tc) for tc in tool_calls]}")
        else:
            tool_calls = None

        # if message["role"] == "function":
        # message["role"] = "tool"

        return Message(
            user_id=self.agent_state.user_id,
            agent_id=self.agent_state.id,
            role=message["role"],
            text=message["content"],
            name=message["name"] if "name" in message else None,
            model=self.agent_state.llm_config.model,
            created_at=timestamp,
            tool_calls=tool_calls,
            tool_call_id=message["tool_call_id"] if "tool_call_id" in message else None,
            id=message["id"] if "id" in message else None,
        )
    '''

    def trim_messages(self, num):
        # printd(f"InMemoryStateManager.trim_messages")
        # self.messages = [self.messages[0]] + self.messages[num:]
        pass

    def prepend_to_messages(self, added_messages: List[Message]):
        # first tag with timestamps
        # added_messages = [{"timestamp": get_local_time(), "message": msg} for msg in added_messages]

        printd(f"{self.__class__.__name__}.prepend_to_message")
        # self.messages = [self.messages[0]] + added_messages + self.messages[1:]

        # add to recall memory

    def append_to_messages(self, added_messages: List[Message]):
        # first tag with timestamps
        # added_messages = [{"timestamp": get_local_time(), "message": msg} for msg in added_messages]

        printd(f"{self.__class__.__name__}.append_to_messages")
        # self.messages = self.messages + added_messages

        # add to recall memory
        self.recall_memory.insert_many([m for m in added_messages])

    def swap_system_message(self, new_system_message: Message):
        # first tag with timestamps
        # new_system_message = {"timestamp": get_local_time(), "message": new_system_message}

        printd(f"{self.__class__.__name__}.swap_system_message")
        # self.messages[0] = new_system_message

        # add to recall memory
        self.recall_memory.insert(new_system_message)

    def update_memory(self, new_memory: Memory):
        printd(f"{self.__class__.__name__}.update_memory")
        assert isinstance(new_memory, Memory), type(new_memory)
        self.memory = new_memory