3fiddlZddlZddlmZddlmZmZddlmZddlm Z m Z m Z ddl m Z mZddlmZddlmZej&eZGd d eZy) N)datetime)ListOptional)BaseChatMessageHistory) BaseMessagemessage_to_dictmessages_from_dict) create_enginetext)SQLAlchemyError) sessionmakerc eZdZdZ ddedededeefdZdd Zdd Z e de e fd Z d e ddfd ZddZddZddZy)TiDBChatMessageHistoryzF Represents a chat message history stored in a TiDB database. N session_idconnection_string table_name earliest_timec||_||_||_g|_t ||_t |j }||_|j|jy)a Initializes a new instance of the TiDBChatMessageHistory class. Args: session_id (str): The ID of the chat session. connection_string (str): The connection string for the TiDB database. format: mysql+pymysql://:@:4000/?ssl_ca=/etc/ssl/cert.pem&ssl_verify_cert=true&ssl_verify_identity=true table_name (str, optional): the table name to store the chat messages. Defaults to "langchain_message_store". earliest_time (Optional[datetime], optional): The earliest time to retrieve messages from. Defaults to None. )bindN) rrrcacher enginer session_create_table_if_not_exists_load_messages_to_cache)selfrrrrSessions m/var/www/auto_recruiter/arenv/lib/python3.12/site-packages/langchain_community/chat_message_histories/tidb.py__init__zTiDBChatMessageHistory.__init__s_(%$* $$56 DKK0y  ((* $$&returnc2td|jd} |jj||jj y#t $r<}t jd||jjYd}~yd}~wwxYw)zO Creates a table if it does not already exist in the database. z( CREATE TABLE IF NOT EXISTS a  ( id INT AUTO_INCREMENT PRIMARY KEY, session_id VARCHAR(255) NOT NULL, message JSON NOT NULL, create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP, INDEX session_idx (session_id) );zError creating table: N) r rrexecutecommitr loggererrorrollback)rcreate_table_queryes rrz2TiDBChatMessageHistory._create_table_if_not_exists5s "((,'89    $ LL !3 4 LL   ! $ LL1!5 6 LL ! ! # # $s5A B2BBc|jrd|jdnd}td|jd|d} |jj |d|j i}|j D]B}tj|d}|jjt|gdDy #t$r"}tjd |Yd }~y d }~wwxYw) a4 Loads messages from the database into the cache. This method retrieves messages from the database table. The retrieved messages are then stored in the cache for faster access. Raises: SQLAlchemyError: If there is an error executing the database query. zAND create_time >= ''z! SELECT message FROM z- WHERE session_id = :session_id z# ORDER BY id; rrz!Error loading messages to cache: N)rr rrr"rfetchalljsonloadsrappendr r r$r%)rtime_conditionqueryresultrecord message_dictr(s rrz.TiDBChatMessageHistory._load_messages_to_cacheKs=ArTsD !>TT**'   8 $E3Er