|
- from typing import Any, List, Mapping
-
- from agnext.components.memory import ChatMemory
- from agnext.components.models import FunctionExecutionResultMessage
-
- from ..types import FunctionCallMessage, Message, TextMessage
-
-
- class HeadAndTailChatMemory(ChatMemory[Message]):
- """A chat memory that keeps a view of the first n and last m messages,
- where n is the head size and m is the tail size. The head and tail sizes
- are set at initialization.
-
- Args:
- head_size (int): The size of the head.
- tail_size (int): The size of the tail.
- """
-
- def __init__(self, head_size: int, tail_size: int) -> None:
- self._messages: List[Message] = []
- self._head_size = head_size
- self._tail_size = tail_size
-
- async def add_message(self, message: Message) -> None:
- """Add a message to the memory."""
- self._messages.append(message)
-
- async def get_messages(self) -> List[Message]:
- """Get at most `head_size` recent messages and `tail_size` oldest messages."""
- head_messages = self._messages[: self._head_size]
- # Handle the last message is a function call message.
- if head_messages and isinstance(head_messages[-1], FunctionCallMessage):
- # Remove the last message from the head.
- head_messages = head_messages[:-1]
-
- tail_messages = self._messages[-self._tail_size :]
- # Handle the first message is a function call result message.
- if tail_messages and isinstance(tail_messages[0], FunctionExecutionResultMessage):
- # Remove the first message from the tail.
- tail_messages = tail_messages[1:]
-
- num_skipped = len(self._messages) - self._head_size - self._tail_size
- if num_skipped <= 0:
- # If there are not enough messages to fill the head and tail,
- # return all messages.
- return self._messages
-
- placeholder_messages = [TextMessage(content=f"Skipped {num_skipped} messages.", source="System")]
- return head_messages + placeholder_messages + tail_messages
-
- async def clear(self) -> None:
- """Clear the message memory."""
- self._messages = []
-
- def save_state(self) -> Mapping[str, Any]:
- return {
- "messages": [message for message in self._messages],
- "head_size": self._head_size,
- "tail_size": self._tail_size,
- "placeholder_message": self._placeholder_message,
- }
-
- def load_state(self, state: Mapping[str, Any]) -> None:
- self._messages = state["messages"]
- self._head_size = state["head_size"]
- self._tail_size = state["tail_size"]
- self._placeholder_message = state["placeholder_message"]
|
