langchain_community.chat_message_histories.cassandra
.CassandraChatMessageHistory¶
- class langchain_community.chat_message_histories.cassandra.CassandraChatMessageHistory(session_id: str, session: Session, keyspace: str, table_name: str = 'message_store', ttl_seconds: Optional[int] = None)[source]¶
Chat message history that stores history in Cassandra.
- Parameters
session_id (str) – arbitrary key that is used to store the messages of a single chat session.
session (Session) – a Cassandra Session object (an open DB connection)
keyspace (str) – name of the keyspace to use.
table_name (str) – name of the table to use.
ttl_seconds (Optional[int]) – time-to-live (seconds) for automatic expiration of stored entries. None (default) for no expiration.
Attributes
messages
Retrieve all session messages from DB
Methods
__init__
(session_id, session, keyspace[, ...])aadd_messages
(messages)Add a list of messages.
aclear
()Remove all messages from the store
add_ai_message
(message)Convenience method for adding an AI message string to the store.
add_message
(message)Write a message to the table
add_messages
(messages)Add a list of messages.
add_user_message
(message)Convenience method for adding a human message string to the store.
Async version of getting messages.
clear
()Clear session memory from DB
- __init__(session_id: str, session: Session, keyspace: str, table_name: str = 'message_store', ttl_seconds: Optional[int] = None) None [source]¶
- Parameters
session_id (str) –
session (Session) –
keyspace (str) –
table_name (str) –
ttl_seconds (Optional[int]) –
- Return type
None
- async aadd_messages(messages: Sequence[BaseMessage]) None ¶
Add a list of messages.
- Parameters
messages (Sequence[BaseMessage]) – A list of BaseMessage objects to store.
- Return type
None
- async aclear() None ¶
Remove all messages from the store
- Return type
None
- add_ai_message(message: Union[AIMessage, str]) None ¶
Convenience method for adding an AI message string to the store.
Please note that this is a convenience method. Code should favor the bulk add_messages interface instead to save on round-trips to the underlying persistence layer.
This method may be deprecated in a future release.
- Parameters
message (Union[AIMessage, str]) – The AI message to add.
- Return type
None
- add_message(message: BaseMessage) None [source]¶
Write a message to the table
- Parameters
message (BaseMessage) –
- Return type
None
- add_messages(messages: Sequence[BaseMessage]) None ¶
Add a list of messages.
Implementations should over-ride this method to handle bulk addition of messages in an efficient manner to avoid unnecessary round-trips to the underlying store.
- Parameters
messages (Sequence[BaseMessage]) – A list of BaseMessage objects to store.
- Return type
None
- add_user_message(message: Union[HumanMessage, str]) None ¶
Convenience method for adding a human message string to the store.
Please note that this is a convenience method. Code should favor the bulk add_messages interface instead to save on round-trips to the underlying persistence layer.
This method may be deprecated in a future release.
- Parameters
message (Union[HumanMessage, str]) – The human message to add
- Return type
None
- async aget_messages() List[BaseMessage] ¶
Async version of getting messages.
Can over-ride this method to provide an efficient async implementation.
In general, fetching messages may involve IO to the underlying persistence layer.
- Return type
List[BaseMessage]