Source code for langchain_astradb.storage

from __future__ import annotations

import base64
from abc import ABC, abstractmethod
from typing import (
    Any,
    AsyncIterator,
    Generic,
    Iterator,
    List,
    Optional,
    Sequence,
    Tuple,
    TypeVar,
)

from astrapy.db import AstraDB, AsyncAstraDB
from langchain_core.stores import BaseStore, ByteStore

from langchain_astradb.utils.astradb import (
    SetupMode,
    _AstraDBCollectionEnvironment,
)

V = TypeVar("V")


[docs]class AstraDBBaseStore(Generic[V], BaseStore[str, V], ABC): """Base class for the DataStax AstraDB data store."""
[docs] def __init__(self, *args: Any, **kwargs: Any) -> None: if "requested_indexing_policy" in kwargs: raise ValueError( "Do not pass 'requested_indexing_policy' to AstraDBBaseStore init" ) if "default_indexing_policy" in kwargs: raise ValueError( "Do not pass 'default_indexing_policy' to AstraDBBaseStore init" ) kwargs["requested_indexing_policy"] = {"allow": ["_id"]} kwargs["default_indexing_policy"] = {"allow": ["_id"]} self.astra_env = _AstraDBCollectionEnvironment( *args, **kwargs, ) self.collection = self.astra_env.collection self.async_collection = self.astra_env.async_collection
[docs] @abstractmethod def decode_value(self, value: Any) -> Optional[V]: """Decodes value from Astra DB"""
[docs] @abstractmethod def encode_value(self, value: Optional[V]) -> Any: """Encodes value for Astra DB"""
[docs] def mget(self, keys: Sequence[str]) -> List[Optional[V]]: self.astra_env.ensure_db_setup() docs_dict = {} for doc in self.collection.paginated_find( filter={"_id": {"$in": list(keys)}}, projection={"*": True}, ): docs_dict[doc["_id"]] = doc.get("value") return [self.decode_value(docs_dict.get(key)) for key in keys]
[docs] async def amget(self, keys: Sequence[str]) -> List[Optional[V]]: await self.astra_env.aensure_db_setup() docs_dict = {} async for doc in self.async_collection.paginated_find( filter={"_id": {"$in": list(keys)}}, projection={"*": True}, ): docs_dict[doc["_id"]] = doc.get("value") return [self.decode_value(docs_dict.get(key)) for key in keys]
[docs] def mset(self, key_value_pairs: Sequence[Tuple[str, V]]) -> None: self.astra_env.ensure_db_setup() for k, v in key_value_pairs: self.collection.upsert_one({"_id": k, "value": self.encode_value(v)})
[docs] async def amset(self, key_value_pairs: Sequence[Tuple[str, V]]) -> None: await self.astra_env.aensure_db_setup() for k, v in key_value_pairs: await self.async_collection.upsert_one( {"_id": k, "value": self.encode_value(v)} )
[docs] def mdelete(self, keys: Sequence[str]) -> None: self.astra_env.ensure_db_setup() self.collection.delete_many(filter={"_id": {"$in": list(keys)}})
[docs] async def amdelete(self, keys: Sequence[str]) -> None: await self.astra_env.aensure_db_setup() await self.async_collection.delete_many(filter={"_id": {"$in": list(keys)}})
[docs] def yield_keys(self, *, prefix: Optional[str] = None) -> Iterator[str]: self.astra_env.ensure_db_setup() docs = self.collection.paginated_find() for doc in docs: key = doc["_id"] if not prefix or key.startswith(prefix): yield key
[docs] async def ayield_keys(self, *, prefix: Optional[str] = None) -> AsyncIterator[str]: await self.astra_env.aensure_db_setup() async for doc in self.async_collection.paginated_find(): key = doc["_id"] if not prefix or key.startswith(prefix): yield key
[docs]class AstraDBStore(AstraDBBaseStore[Any]):
[docs] def __init__( self, collection_name: str, *, token: Optional[str] = None, api_endpoint: Optional[str] = None, astra_db_client: Optional[AstraDB] = None, namespace: Optional[str] = None, async_astra_db_client: Optional[AsyncAstraDB] = None, pre_delete_collection: bool = False, setup_mode: SetupMode = SetupMode.SYNC, ) -> None: """BaseStore implementation using DataStax AstraDB as the underlying store. The value type can be any type serializable by json.dumps. Can be used to store embeddings with the CacheBackedEmbeddings. Documents in the AstraDB collection will have the format .. code-block:: json { "_id": "<key>", "value": <value> } Args: collection_name: name of the Astra DB collection to create/use. token: API token for Astra DB usage. If not provided, the environment variable ASTRA_DB_APPLICATION_TOKEN is inspected. api_endpoint: full URL to the API endpoint, such as `https://<DB-ID>-us-east1.apps.astra.datastax.com`. If not provided, the environment variable ASTRA_DB_API_ENDPOINT is inspected. 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. If not provided, the environment variable ASTRA_DB_KEYSPACE is inspected. 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. """ super().__init__( 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, )
[docs] def decode_value(self, value: Any) -> Any: return value
[docs] def encode_value(self, value: Any) -> Any: return value
[docs]class AstraDBByteStore(AstraDBBaseStore[bytes], ByteStore):
[docs] def __init__( self, *, collection_name: str, token: Optional[str] = None, api_endpoint: Optional[str] = None, astra_db_client: Optional[AstraDB] = None, namespace: Optional[str] = None, async_astra_db_client: Optional[AsyncAstraDB] = None, pre_delete_collection: bool = False, setup_mode: SetupMode = SetupMode.SYNC, ) -> None: """ByteStore implementation using DataStax AstraDB as the underlying store. The bytes values are converted to base64 encoded strings Documents in the AstraDB collection will have the format .. code-block:: json { "_id": "<key>", "value": "<byte64 string value>" } Args: collection_name: name of the Astra DB collection to create/use. token: API token for Astra DB usage. If not provided, the environment variable ASTRA_DB_APPLICATION_TOKEN is inspected. api_endpoint: full URL to the API endpoint, such as `https://<DB-ID>-us-east1.apps.astra.datastax.com`. If not provided, the environment variable ASTRA_DB_API_ENDPOINT is inspected. 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. If not provided, the environment variable ASTRA_DB_KEYSPACE is inspected. 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. """ super().__init__( 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, )
[docs] def decode_value(self, value: Any) -> Optional[bytes]: if value is None: return None return base64.b64decode(value)
[docs] def encode_value(self, value: Optional[bytes]) -> Any: if value is None: return None return base64.b64encode(value).decode("ascii")