"""Astra DB - based chat message history, based on astrapy."""
from __future__ import annotations
import json
import time
from typing import TYPE_CHECKING, List, Optional, Sequence
from langchain_community.utilities.astradb import (
SetupMode,
_AstraDBCollectionEnvironment,
)
if TYPE_CHECKING:
from astrapy.db import AstraDB, AsyncAstraDB
from langchain_core._api.deprecation import deprecated
from langchain_core.chat_history import BaseChatMessageHistory
from langchain_core.messages import (
BaseMessage,
message_to_dict,
messages_from_dict,
)
DEFAULT_COLLECTION_NAME = "langchain_message_store"
[docs]@deprecated(
since="0.0.25",
removal="1.0",
alternative_import="langchain_astradb.AstraDBChatMessageHistory",
)
class AstraDBChatMessageHistory(BaseChatMessageHistory):
[docs] def __init__(
self,
*,
session_id: str,
collection_name: str = DEFAULT_COLLECTION_NAME,
token: Optional[str] = None,
api_endpoint: Optional[str] = None,
astra_db_client: Optional[AstraDB] = None,
async_astra_db_client: Optional[AsyncAstraDB] = None,
namespace: Optional[str] = None,
setup_mode: SetupMode = SetupMode.SYNC,
pre_delete_collection: bool = False,
) -> None:
"""Chat message history that stores history in Astra DB.
Args:
session_id: arbitrary key that is used to store the messages
of a single chat session.
collection_name: name of the Astra DB collection to create/use.
token: API token for Astra DB usage.
api_endpoint: full URL to the API endpoint,
such as "https://<DB-ID>-us-east1.apps.astra.datastax.com".
astra_db_client: *alternative to token+api_endpoint*,
you can pass an already-created 'astrapy.db.AstraDB' instance.
async_astra_db_client: *alternative to token+api_endpoint*,
you can pass an already-created 'astrapy.db.AsyncAstraDB' instance.
namespace: namespace (aka keyspace) where the
collection is created. Defaults to the database's "default namespace".
setup_mode: mode used to create the Astra DB collection (SYNC, ASYNC or
OFF).
pre_delete_collection: whether to delete the collection
before creating it. If False and the collection already exists,
the collection will be used as is.
"""
self.astra_env = _AstraDBCollectionEnvironment(
collection_name=collection_name,
token=token,
api_endpoint=api_endpoint,
astra_db_client=astra_db_client,
async_astra_db_client=async_astra_db_client,
namespace=namespace,
setup_mode=setup_mode,
pre_delete_collection=pre_delete_collection,
)
self.collection = self.astra_env.collection
self.async_collection = self.astra_env.async_collection
self.session_id = session_id
self.collection_name = collection_name
@property
def messages(self) -> List[BaseMessage]:
"""Retrieve all session messages from DB"""
self.astra_env.ensure_db_setup()
message_blobs = [
doc["body_blob"]
for doc in sorted(
self.collection.paginated_find(
filter={
"session_id": self.session_id,
},
projection={
"timestamp": 1,
"body_blob": 1,
},
),
key=lambda _doc: _doc["timestamp"],
)
]
items = [json.loads(message_blob) for message_blob in message_blobs]
messages = messages_from_dict(items)
return messages
@messages.setter
def messages(self, messages: List[BaseMessage]) -> None:
raise NotImplementedError("Use add_messages instead")
[docs] async def aget_messages(self) -> List[BaseMessage]:
await self.astra_env.aensure_db_setup()
docs = self.async_collection.paginated_find(
filter={
"session_id": self.session_id,
},
projection={
"timestamp": 1,
"body_blob": 1,
},
)
sorted_docs = sorted(
[doc async for doc in docs],
key=lambda _doc: _doc["timestamp"],
)
message_blobs = [doc["body_blob"] for doc in sorted_docs]
items = [json.loads(message_blob) for message_blob in message_blobs]
messages = messages_from_dict(items)
return messages
[docs] def add_messages(self, messages: Sequence[BaseMessage]) -> None:
self.astra_env.ensure_db_setup()
docs = [
{
"timestamp": time.time(),
"session_id": self.session_id,
"body_blob": json.dumps(message_to_dict(message)),
}
for message in messages
]
self.collection.chunked_insert_many(docs)
[docs] async def aadd_messages(self, messages: Sequence[BaseMessage]) -> None:
await self.astra_env.aensure_db_setup()
docs = [
{
"timestamp": time.time(),
"session_id": self.session_id,
"body_blob": json.dumps(message_to_dict(message)),
}
for message in messages
]
await self.async_collection.chunked_insert_many(docs)
[docs] def clear(self) -> None:
self.astra_env.ensure_db_setup()
self.collection.delete_many(filter={"session_id": self.session_id})
[docs] async def aclear(self) -> None:
await self.astra_env.aensure_db_setup()
await self.async_collection.delete_many(filter={"session_id": self.session_id})
