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Add AstraDBStore to langchain-astradb package
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cbornet committed Feb 20, 2024
1 parent 865cabf commit 7c0109e
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11 changes: 11 additions & 0 deletions libs/community/langchain_community/storage/astradb.py
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
TypeVar,
)

from langchain_core._api.deprecation import deprecated
from langchain_core.stores import BaseStore, ByteStore

from langchain_community.utilities.astradb import (
Expand Down Expand Up @@ -124,6 +125,11 @@ async def ayield_keys(self, *, prefix: Optional[str] = None) -> AsyncIterator[st
yield key


@deprecated(
since="0.1.24",
removal="0.2.0",
alternative_import="langchain_astradb.AstraDBStore",
)
class AstraDBStore(AstraDBBaseStore[Any]):
"""BaseStore implementation using DataStax AstraDB as the underlying store.
Expand All @@ -143,6 +149,11 @@ def encode_value(self, value: Any) -> Any:
return value


@deprecated(
since="0.1.24",
removal="0.2.0",
alternative_import="langchain_astradb.AstraDBByteStore",
)
class AstraDBByteStore(AstraDBBaseStore[bytes], ByteStore):
"""ByteStore implementation using DataStax AstraDB as the underlying store.
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3 changes: 3 additions & 0 deletions libs/partners/astradb/langchain_astradb/__init__.py
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@@ -1,5 +1,8 @@
from langchain_astradb.storage import AstraDBByteStore, AstraDBStore
from langchain_astradb.vectorstores import AstraDBVectorStore

__all__ = [
"AstraDBByteStore",
"AstraDBStore",
"AstraDBVectorStore",
]
217 changes: 217 additions & 0 deletions libs/partners/astradb/langchain_astradb/storage.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,217 @@
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")


class AstraDBBaseStore(Generic[V], BaseStore[str, V], ABC):
"""Base class for the DataStax AstraDB data store."""

def __init__(self, *args: Any, **kwargs: Any) -> None:
self.astra_env = _AstraDBCollectionEnvironment(*args, **kwargs)
self.collection = self.astra_env.collection
self.async_collection = self.astra_env.async_collection

@abstractmethod
def decode_value(self, value: Any) -> Optional[V]:
"""Decodes value from Astra DB"""

@abstractmethod
def encode_value(self, value: Optional[V]) -> Any:
"""Encodes value for Astra DB"""

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)}}):
docs_dict[doc["_id"]] = doc.get("value")
return [self.decode_value(docs_dict.get(key)) for key in keys]

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)}}
):
docs_dict[doc["_id"]] = doc.get("value")
return [self.decode_value(docs_dict.get(key)) for key in keys]

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({"_id": k, "value": self.encode_value(v)})

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(
{"_id": k, "value": self.encode_value(v)}
)

def mdelete(self, keys: Sequence[str]) -> None:
self.astra_env.ensure_db_setup()
self.collection.delete_many(filter={"_id": {"$in": list(keys)}})

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)}})

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

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


class AstraDBStore(AstraDBBaseStore[Any]):
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.
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.
"""
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,
)

def decode_value(self, value: Any) -> Any:
return value

def encode_value(self, value: Any) -> Any:
return value


class AstraDBByteStore(AstraDBBaseStore[bytes], ByteStore):
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.
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.
"""
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,
)

def decode_value(self, value: Any) -> Optional[bytes]:
if value is None:
return None
return base64.b64decode(value)

def encode_value(self, value: Optional[bytes]) -> Any:
if value is None:
return None
return base64.b64encode(value).decode("ascii")

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