import json
import logging
from time import time
from typing import TYPE_CHECKING, Any, Dict, List, Optional
from langchain_core._api import deprecated
from langchain_core.chat_history import BaseChatMessageHistory
from langchain_core.messages import (
BaseMessage,
message_to_dict,
messages_from_dict,
)
if TYPE_CHECKING:
from elasticsearch import Elasticsearch
logger = logging.getLogger(__name__)
[docs]
@deprecated("0.0.27", alternative="Use langchain-elasticsearch package", pending=True)
class ElasticsearchChatMessageHistory(BaseChatMessageHistory):
"""Chat message history that stores history in Elasticsearch.
Args:
es_url: URL of the Elasticsearch instance to connect to.
es_cloud_id: Cloud ID of the Elasticsearch instance to connect to.
es_user: Username to use when connecting to Elasticsearch.
es_password: Password to use when connecting to Elasticsearch.
es_api_key: API key to use when connecting to Elasticsearch.
es_connection: Optional pre-existing Elasticsearch connection.
ensure_ascii: Used to escape ASCII symbols in json.dumps. Defaults to True.
index: Name of the index to use.
session_id: Arbitrary key that is used to store the messages
of a single chat session.
"""
[docs]
def __init__(
self,
index: str,
session_id: str,
*,
es_connection: Optional["Elasticsearch"] = None,
es_url: Optional[str] = None,
es_cloud_id: Optional[str] = None,
es_user: Optional[str] = None,
es_api_key: Optional[str] = None,
es_password: Optional[str] = None,
ensure_ascii: Optional[bool] = True,
):
self.index: str = index
self.session_id: str = session_id
self.ensure_ascii = ensure_ascii
# Initialize Elasticsearch client from passed client arg or connection info
if es_connection is not None:
self.client = es_connection.options(
headers={"user-agent": self.get_user_agent()}
)
elif es_url is not None or es_cloud_id is not None:
self.client = ElasticsearchChatMessageHistory.connect_to_elasticsearch(
es_url=es_url,
username=es_user,
password=es_password,
cloud_id=es_cloud_id,
api_key=es_api_key,
)
else:
raise ValueError(
"""Either provide a pre-existing Elasticsearch connection, \
or valid credentials for creating a new connection."""
)
if self.client.indices.exists(index=index):
logger.debug(
f"Chat history index {index} already exists, skipping creation."
)
else:
logger.debug(f"Creating index {index} for storing chat history.")
self.client.indices.create(
index=index,
mappings={
"properties": {
"session_id": {"type": "keyword"},
"created_at": {"type": "date"},
"history": {"type": "text"},
}
},
)
[docs]
@staticmethod
def get_user_agent() -> str:
from langchain_community import __version__
return f"langchain-py-ms/{__version__}"
[docs]
@staticmethod
def connect_to_elasticsearch(
*,
es_url: Optional[str] = None,
cloud_id: Optional[str] = None,
api_key: Optional[str] = None,
username: Optional[str] = None,
password: Optional[str] = None,
) -> "Elasticsearch":
try:
import elasticsearch
except ImportError:
raise ImportError(
"Could not import elasticsearch python package. "
"Please install it with `pip install elasticsearch`."
)
if es_url and cloud_id:
raise ValueError(
"Both es_url and cloud_id are defined. Please provide only one."
)
connection_params: Dict[str, Any] = {}
if es_url:
connection_params["hosts"] = [es_url]
elif cloud_id:
connection_params["cloud_id"] = cloud_id
else:
raise ValueError("Please provide either elasticsearch_url or cloud_id.")
if api_key:
connection_params["api_key"] = api_key
elif username and password:
connection_params["basic_auth"] = (username, password)
es_client = elasticsearch.Elasticsearch(
**connection_params,
headers={"user-agent": ElasticsearchChatMessageHistory.get_user_agent()},
)
try:
es_client.info()
except Exception as err:
logger.error(f"Error connecting to Elasticsearch: {err}")
raise err
return es_client
@property
def messages(self) -> List[BaseMessage]:
"""Retrieve the messages from Elasticsearch"""
try:
from elasticsearch import ApiError
result = self.client.search(
index=self.index,
query={"term": {"session_id": self.session_id}},
sort="created_at:asc",
)
except ApiError as err:
logger.error(f"Could not retrieve messages from Elasticsearch: {err}")
raise err
if result and len(result["hits"]["hits"]) > 0:
items = [
json.loads(document["_source"]["history"])
for document in result["hits"]["hits"]
]
else:
items = []
return messages_from_dict(items)
@messages.setter
def messages(self, messages: List[BaseMessage]) -> None:
raise NotImplementedError(
"Direct assignment to 'messages' is not allowed."
" Use the 'add_messages' instead."
)
[docs]
def add_message(self, message: BaseMessage) -> None:
"""Add a message to the chat session in Elasticsearch"""
try:
from elasticsearch import ApiError
self.client.index(
index=self.index,
document={
"session_id": self.session_id,
"created_at": round(time() * 1000),
"history": json.dumps(
message_to_dict(message),
ensure_ascii=bool(self.ensure_ascii),
),
},
refresh=True,
)
except ApiError as err:
logger.error(f"Could not add message to Elasticsearch: {err}")
raise err
[docs]
def clear(self) -> None:
"""Clear session memory in Elasticsearch"""
try:
from elasticsearch import ApiError
self.client.delete_by_query(
index=self.index,
query={"term": {"session_id": self.session_id}},
refresh=True,
)
except ApiError as err:
logger.error(f"Could not clear session memory in Elasticsearch: {err}")
raise err
