buffer.py — langchain Source File

Source Code

from typing import Any

from langchain_core._api import deprecated
from langchain_core.messages import BaseMessage, get_buffer_string
from langchain_core.utils import pre_init
from typing_extensions import override

from langchain_classic.base_memory import BaseMemory
from langchain_classic.memory.chat_memory import BaseChatMemory
from langchain_classic.memory.utils import get_prompt_input_key


@deprecated(
    since="0.3.1",
    removal="1.0.0",
    message=(
        "Please see the migration guide at: "
        "https://python.langchain.com/docs/versions/migrating_memory/"
    ),
)
class ConversationBufferMemory(BaseChatMemory):
    """A basic memory implementation that simply stores the conversation history.

    This stores the entire conversation history in memory without any
    additional processing.

    Note that additional processing may be required in some situations when the
    conversation history is too large to fit in the context window of the model.
    """

    human_prefix: str = "Human"
    ai_prefix: str = "AI"
    memory_key: str = "history"

    @property
    def buffer(self) -> Any:
        """String buffer of memory."""
        return self.buffer_as_messages if self.return_messages else self.buffer_as_str

    async def abuffer(self) -> Any:
        """String buffer of memory."""
        return (
            await self.abuffer_as_messages()
            if self.return_messages
            else await self.abuffer_as_str()
        )

    def _buffer_as_str(self, messages: list[BaseMessage]) -> str:
        return get_buffer_string(
            messages,
            human_prefix=self.human_prefix,
            ai_prefix=self.ai_prefix,
        )

    @property
    def buffer_as_str(self) -> str:
        """Exposes the buffer as a string in case return_messages is True."""
        return self._buffer_as_str(self.chat_memory.messages)

    async def abuffer_as_str(self) -> str:
// ... (114 more lines)