Add "Astra DB" vector store integration (#12966)

# Astra DB Vector store integration

- **Description:** This PR adds a `VectorStore` implementation for
DataStax Astra DB using its HTTP API
  - **Issue:** (no related issue)
- **Dependencies:** A new required dependency is `astrapy` (`>=0.5.3`)
which was added to pyptoject.toml, optional, as per guidelines
- **Tag maintainer:** I recently mentioned to @baskaryan this
integration was coming
  - **Twitter handle:** `@rsprrs` if you want to mention me

This PR introduces the `AstraDB` vector store class, extensive
integration test coverage, a reworking of the documentation which
conflates Cassandra and Astra DB on a single "provider" page and a new,
completely reworked vector-store example notebook (common to the
Cassandra store, since parts of the flow is shared by the two APIs). I
also took care in ensuring docs (and redirects therein) are behaving
correctly.

All style, linting, typechecks and tests pass as far as the `AstraDB`
integration is concerned.

I could build the documentation and check it all right (but ran into
trouble with the `api_docs_build` makefile target which I could not
verify: `Error: Unable to import module
'plan_and_execute.agent_executor' with error: No module named
'langchain_experimental'` was the first of many similar errors)

Thank you for a review!
Stefano

---------

Co-authored-by: Erick Friis <erick@langchain.dev>
This commit is contained in:
Stefano Lottini
2023-11-07 23:45:33 +01:00
committed by GitHub
parent 13bd83bd61
commit 4f4b020582
21 changed files with 4376 additions and 376 deletions

View File

@@ -104,6 +104,12 @@ def _import_cassandra() -> Any:
return Cassandra
def _import_astradb() -> Any:
from langchain.vectorstores.astradb import AstraDB
return AstraDB
def _import_chroma() -> Any:
from langchain.vectorstores.chroma import Chroma
@@ -443,6 +449,8 @@ def __getattr__(name: str) -> Any:
return _import_baiducloud_vector_search()
elif name == "Cassandra":
return _import_cassandra()
elif name == "AstraDB":
return _import_astradb()
elif name == "Chroma":
return _import_chroma()
elif name == "Clarifai":
@@ -561,6 +569,7 @@ __all__ = [
"AzureSearch",
"Bagel",
"Cassandra",
"AstraDB",
"Chroma",
"Clarifai",
"Clickhouse",

View File

@@ -0,0 +1,751 @@
from __future__ import annotations
import uuid
import warnings
from concurrent.futures import ThreadPoolExecutor
from typing import (
Any,
Callable,
Dict,
Iterable,
List,
Optional,
Set,
Tuple,
Type,
TypeVar,
)
import numpy as np
from langchain.docstore.document import Document
from langchain.schema.embeddings import Embeddings
from langchain.schema.vectorstore import VectorStore
from langchain.utils.iter import batch_iterate
from langchain.vectorstores.utils import maximal_marginal_relevance
ADBVST = TypeVar("ADBVST", bound="AstraDB")
T = TypeVar("T")
U = TypeVar("U")
DocDict = Dict[str, Any] # dicts expressing entries to insert
# Batch/concurrency default values (if parameters not provided):
# Size of batches for bulk insertions:
# (20 is the max batch size for the HTTP API at the time of writing)
DEFAULT_BATCH_SIZE = 20
# Number of threads to insert batches concurrently:
DEFAULT_BULK_INSERT_BATCH_CONCURRENCY = 5
# Number of threads in a batch to insert pre-existing entries:
DEFAULT_BULK_INSERT_OVERWRITE_CONCURRENCY = 10
# Number of threads (for deleting multiple rows concurrently):
DEFAULT_BULK_DELETE_CONCURRENCY = 20
def _unique_list(lst: List[T], key: Callable[[T], U]) -> List[T]:
visited_keys: Set[U] = set()
new_lst = []
for item in lst:
item_key = key(item)
if item_key not in visited_keys:
visited_keys.add(item_key)
new_lst.append(item)
return new_lst
class AstraDB(VectorStore):
"""Wrapper around DataStax Astra DB for vector-store workloads.
To use it, you need a recent installation of the `astrapy` library
and an Astra DB cloud database.
For quickstart and details, visit:
docs.datastax.com/en/astra/home/astra.html
Example:
.. code-block:: python
from langchain.vectorstores import AstraDB
from langchain.embeddings.openai import OpenAIEmbeddings
embeddings = OpenAIEmbeddings()
vectorstore = AstraDB(
embedding=embeddings,
collection_name="my_store",
token="AstraCS:...",
api_endpoint="https://<DB-ID>-us-east1.apps.astra.datastax.com"
)
vectorstore.add_texts(["Giraffes", "All good here"])
results = vectorstore.similarity_search("Everything's ok", k=1)
"""
@staticmethod
def _filter_to_metadata(filter_dict: Optional[Dict[str, str]]) -> Dict[str, Any]:
if filter_dict is None:
return {}
else:
return {f"metadata.{mdk}": mdv for mdk, mdv in filter_dict.items()}
def __init__(
self,
*,
embedding: Embeddings,
collection_name: str,
token: Optional[str] = None,
api_endpoint: Optional[str] = None,
astra_db_client: Optional[Any] = None, # 'astrapy.db.AstraDB' if passed
namespace: Optional[str] = None,
metric: Optional[str] = None,
batch_size: Optional[int] = None,
bulk_insert_batch_concurrency: Optional[int] = None,
bulk_insert_overwrite_concurrency: Optional[int] = None,
bulk_delete_concurrency: Optional[int] = None,
) -> None:
try:
from astrapy.db import (
AstraDB as LibAstraDB,
)
from astrapy.db import (
AstraDBCollection as LibAstraDBCollection,
)
except (ImportError, ModuleNotFoundError):
raise ImportError(
"Could not import a recent astrapy python package. "
"Please install it with `pip install --upgrade astrapy`."
)
"""
Create an AstraDB vector store object.
Args (only keyword-arguments accepted):
embedding (Embeddings): embedding function to use.
collection_name (str): name of the Astra DB collection to create/use.
token (Optional[str]): API token for Astra DB usage.
api_endpoint (Optional[str]): full URL to the API endpoint,
such as "https://<DB-ID>-us-east1.apps.astra.datastax.com".
astra_db_client (Optional[Any]): *alternative to token+api_endpoint*,
you can pass an already-created 'astrapy.db.AstraDB' instance.
namespace (Optional[str]): namespace (aka keyspace) where the
collection is created. Defaults to the database's "default namespace".
metric (Optional[str]): similarity function to use out of those
available in Astra DB. If left out, it will use Astra DB API's
defaults (i.e. "cosine" - but, for performance reasons,
"dot_product" is suggested if embeddings are normalized to one).
Advanced arguments (coming with sensible defaults):
batch_size (Optional[int]): Size of batches for bulk insertions.
bulk_insert_batch_concurrency (Optional[int]): Number of threads
to insert batches concurrently.
bulk_insert_overwrite_concurrency (Optional[int]): Number of
threads in a batch to insert pre-existing entries.
bulk_delete_concurrency (Optional[int]): Number of threads
(for deleting multiple rows concurrently).
"""
# Conflicting-arg checks:
if astra_db_client is not None:
if token is not None or api_endpoint is not None:
raise ValueError(
"You cannot pass 'astra_db_client' to AstraDB if passing "
"'token' and 'api_endpoint'."
)
self.embedding = embedding
self.collection_name = collection_name
self.token = token
self.api_endpoint = api_endpoint
self.namespace = namespace
# Concurrency settings
self.batch_size: int = batch_size or DEFAULT_BATCH_SIZE
self.bulk_insert_batch_concurrency: int = (
bulk_insert_batch_concurrency or DEFAULT_BULK_INSERT_BATCH_CONCURRENCY
)
self.bulk_insert_overwrite_concurrency: int = (
bulk_insert_overwrite_concurrency
or DEFAULT_BULK_INSERT_OVERWRITE_CONCURRENCY
)
self.bulk_delete_concurrency: int = (
bulk_delete_concurrency or DEFAULT_BULK_DELETE_CONCURRENCY
)
# "vector-related" settings
self._embedding_dimension: Optional[int] = None
self.metric = metric
if astra_db_client is not None:
self.astra_db = astra_db_client
else:
self.astra_db = LibAstraDB(
token=self.token,
api_endpoint=self.api_endpoint,
namespace=self.namespace,
)
self._provision_collection()
self.collection = LibAstraDBCollection(
collection_name=self.collection_name,
astra_db=self.astra_db,
)
def _get_embedding_dimension(self) -> int:
if self._embedding_dimension is None:
self._embedding_dimension = len(
self.embedding.embed_query("This is a sample sentence.")
)
return self._embedding_dimension
def _drop_collection(self) -> None:
"""
Drop the collection from storage.
This is meant as an internal-usage method, no members
are set other than actual deletion on the backend.
"""
_ = self.astra_db.delete_collection(
collection_name=self.collection_name,
)
return None
def _provision_collection(self) -> None:
"""
Run the API invocation to create the collection on the backend.
Internal-usage method, no object members are set,
other than working on the underlying actual storage.
"""
_ = self.astra_db.create_collection(
dimension=self._get_embedding_dimension(),
collection_name=self.collection_name,
metric=self.metric,
)
return None
@property
def embeddings(self) -> Embeddings:
return self.embedding
@staticmethod
def _dont_flip_the_cos_score(similarity0to1: float) -> float:
"""Keep similarity from client unchanged ad it's in [0:1] already."""
return similarity0to1
def _select_relevance_score_fn(self) -> Callable[[float], float]:
"""
The underlying API calls already returns a "score proper",
i.e. one in [0, 1] where higher means more *similar*,
so here the final score transformation is not reversing the interval:
"""
return self._dont_flip_the_cos_score
def clear(self) -> None:
"""Empty the collection of all its stored entries."""
self._drop_collection()
self._provision_collection()
return None
def delete_by_document_id(self, document_id: str) -> bool:
"""
Remove a single document from the store, given its document_id (str).
Return True if a document has indeed been deleted, False if ID not found.
"""
deletion_response = self.collection.delete(document_id)
return ((deletion_response or {}).get("status") or {}).get(
"deletedCount", 0
) == 1
def delete(
self,
ids: Optional[List[str]] = None,
concurrency: Optional[int] = None,
**kwargs: Any,
) -> Optional[bool]:
"""Delete by vector ids.
Args:
ids (Optional[List[str]]): List of ids to delete.
concurrency (Optional[int]): max number of threads issuing
single-doc delete requests. Defaults to instance-level setting.
Returns:
Optional[bool]: True if deletion is successful,
False otherwise, None if not implemented.
"""
if kwargs:
warnings.warn(
"Method 'delete' of AstraDB vector store invoked with "
f"unsupported arguments ({', '.join(sorted(kwargs.keys()))}), "
"which will be ignored."
)
if ids is None:
raise ValueError("No ids provided to delete.")
_max_workers = concurrency or self.bulk_delete_concurrency
with ThreadPoolExecutor(max_workers=_max_workers) as tpe:
_ = list(
tpe.map(
self.delete_by_document_id,
ids,
)
)
return True
def delete_collection(self) -> None:
"""
Completely delete the collection from the database (as opposed
to 'clear()', which empties it only).
Stored data is lost and unrecoverable, resources are freed.
Use with caution.
"""
self._drop_collection()
return None
def add_texts(
self,
texts: Iterable[str],
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
*,
batch_size: Optional[int] = None,
batch_concurrency: Optional[int] = None,
overwrite_concurrency: Optional[int] = None,
**kwargs: Any,
) -> List[str]:
"""Run texts through the embeddings and add them to the vectorstore.
If passing explicit ids, those entries whose id is in the store already
will be replaced.
Args:
texts (Iterable[str]): Texts to add to the vectorstore.
metadatas (Optional[List[dict]], optional): Optional list of metadatas.
ids (Optional[List[str]], optional): Optional list of ids.
batch_size (Optional[int]): Number of documents in each API call.
Check the underlying Astra DB HTTP API specs for the max value
(20 at the time of writing this). If not provided, defaults
to the instance-level setting.
batch_concurrency (Optional[int]): number of threads to process
insertion batches concurrently. Defaults to instance-level
setting if not provided.
overwrite_concurrency (Optional[int]): number of threads to process
pre-existing documents in each batch (which require individual
API calls). Defaults to instance-level setting if not provided.
Returns:
List[str]: List of ids of the added texts.
"""
if kwargs:
warnings.warn(
"Method 'add_texts' of AstraDB vector store invoked with "
f"unsupported arguments ({', '.join(sorted(kwargs.keys()))}), "
"which will be ignored."
)
_texts = list(texts)
if ids is None:
ids = [uuid.uuid4().hex for _ in _texts]
if metadatas is None:
metadatas = [{} for _ in _texts]
#
embedding_vectors = self.embedding.embed_documents(_texts)
documents_to_insert = [
{
"content": b_txt,
"_id": b_id,
"$vector": b_emb,
"metadata": b_md,
}
for b_txt, b_emb, b_id, b_md in zip(
_texts,
embedding_vectors,
ids,
metadatas,
)
]
# make unique by id, keeping the last
uniqued_documents_to_insert = _unique_list(
documents_to_insert[::-1],
lambda document: document["_id"],
)[::-1]
all_ids = []
def _handle_batch(document_batch: List[DocDict]) -> List[str]:
im_result = self.collection.insert_many(
documents=document_batch,
options={"ordered": False},
partial_failures_allowed=True,
)
if "status" not in im_result:
raise ValueError(
f"API Exception while running bulk insertion: {str(im_result)}"
)
batch_inserted = im_result["status"]["insertedIds"]
# estimation of the preexisting documents that failed
missed_inserted_ids = {
document["_id"] for document in document_batch
} - set(batch_inserted)
errors = im_result.get("errors", [])
# careful for other sources of error other than "doc already exists"
num_errors = len(errors)
unexpected_errors = any(
error.get("errorCode") != "DOCUMENT_ALREADY_EXISTS" for error in errors
)
if num_errors != len(missed_inserted_ids) or unexpected_errors:
raise ValueError(
f"API Exception while running bulk insertion: {str(errors)}"
)
# deal with the missing insertions as upserts
missing_from_batch = [
document
for document in document_batch
if document["_id"] in missed_inserted_ids
]
def _handle_missing_document(missing_document: DocDict) -> str:
replacement_result = self.collection.find_one_and_replace(
filter={"_id": missing_document["_id"]},
replacement=missing_document,
)
return replacement_result["data"]["document"]["_id"]
_u_max_workers = (
overwrite_concurrency or self.bulk_insert_overwrite_concurrency
)
with ThreadPoolExecutor(max_workers=_u_max_workers) as tpe2:
batch_replaced = list(
tpe2.map(
_handle_missing_document,
missing_from_batch,
)
)
upsert_ids = batch_inserted + batch_replaced
return upsert_ids
_b_max_workers = batch_concurrency or self.bulk_insert_batch_concurrency
with ThreadPoolExecutor(max_workers=_b_max_workers) as tpe:
all_ids_nested = tpe.map(
_handle_batch,
batch_iterate(
batch_size or self.batch_size,
uniqued_documents_to_insert,
),
)
all_ids = [iid for id_list in all_ids_nested for iid in id_list]
return all_ids
def similarity_search_with_score_id_by_vector(
self,
embedding: List[float],
k: int = 4,
filter: Optional[Dict[str, str]] = None,
) -> List[Tuple[Document, float, str]]:
"""Return docs most similar to embedding vector.
Args:
embedding (str): Embedding to look up documents similar to.
k (int): Number of Documents to return. Defaults to 4.
Returns:
List of (Document, score, id), the most similar to the query vector.
"""
metadata_parameter = self._filter_to_metadata(filter)
#
hits = list(
self.collection.paginated_find(
filter=metadata_parameter,
sort={"$vector": embedding},
options={"limit": k},
projection={
"_id": 1,
"content": 1,
"metadata": 1,
"$similarity": 1,
},
)
)
#
return [
(
Document(
page_content=hit["content"],
metadata=hit["metadata"],
),
hit["$similarity"],
hit["_id"],
)
for hit in hits
]
def similarity_search_with_score_id(
self,
query: str,
k: int = 4,
filter: Optional[Dict[str, str]] = None,
) -> List[Tuple[Document, float, str]]:
embedding_vector = self.embedding.embed_query(query)
return self.similarity_search_with_score_id_by_vector(
embedding=embedding_vector,
k=k,
filter=filter,
)
def similarity_search_with_score_by_vector(
self,
embedding: List[float],
k: int = 4,
filter: Optional[Dict[str, str]] = None,
) -> List[Tuple[Document, float]]:
"""Return docs most similar to embedding vector.
Args:
embedding (str): Embedding to look up documents similar to.
k (int): Number of Documents to return. Defaults to 4.
Returns:
List of (Document, score), the most similar to the query vector.
"""
return [
(doc, score)
for (doc, score, doc_id) in self.similarity_search_with_score_id_by_vector(
embedding=embedding,
k=k,
filter=filter,
)
]
def similarity_search(
self,
query: str,
k: int = 4,
filter: Optional[Dict[str, str]] = None,
**kwargs: Any,
) -> List[Document]:
embedding_vector = self.embedding.embed_query(query)
return self.similarity_search_by_vector(
embedding_vector,
k,
filter=filter,
)
def similarity_search_by_vector(
self,
embedding: List[float],
k: int = 4,
filter: Optional[Dict[str, str]] = None,
**kwargs: Any,
) -> List[Document]:
return [
doc
for doc, _ in self.similarity_search_with_score_by_vector(
embedding,
k,
filter=filter,
)
]
def similarity_search_with_score(
self,
query: str,
k: int = 4,
filter: Optional[Dict[str, str]] = None,
) -> List[Tuple[Document, float]]:
embedding_vector = self.embedding.embed_query(query)
return self.similarity_search_with_score_by_vector(
embedding_vector,
k,
filter=filter,
)
def max_marginal_relevance_search_by_vector(
self,
embedding: List[float],
k: int = 4,
fetch_k: int = 20,
lambda_mult: float = 0.5,
filter: Optional[Dict[str, str]] = None,
**kwargs: Any,
) -> List[Document]:
"""Return docs selected using the maximal marginal relevance.
Maximal marginal relevance optimizes for similarity to query AND diversity
among selected documents.
Args:
embedding: Embedding to look up documents similar to.
k: Number of Documents to return.
fetch_k: Number of Documents to fetch to pass to MMR algorithm.
lambda_mult: Number between 0 and 1 that determines the degree
of diversity among the results with 0 corresponding
to maximum diversity and 1 to minimum diversity.
Returns:
List of Documents selected by maximal marginal relevance.
"""
metadata_parameter = self._filter_to_metadata(filter)
prefetch_hits = list(
self.collection.paginated_find(
filter=metadata_parameter,
sort={"$vector": embedding},
options={"limit": fetch_k},
projection={
"_id": 1,
"content": 1,
"metadata": 1,
"$similarity": 1,
"$vector": 1,
},
)
)
mmr_chosen_indices = maximal_marginal_relevance(
np.array(embedding, dtype=np.float32),
[prefetch_hit["$vector"] for prefetch_hit in prefetch_hits],
k=k,
lambda_mult=lambda_mult,
)
mmr_hits = [
prefetch_hit
for prefetch_index, prefetch_hit in enumerate(prefetch_hits)
if prefetch_index in mmr_chosen_indices
]
return [
Document(
page_content=hit["content"],
metadata=hit["metadata"],
)
for hit in mmr_hits
]
def max_marginal_relevance_search(
self,
query: str,
k: int = 4,
fetch_k: int = 20,
lambda_mult: float = 0.5,
filter: Optional[Dict[str, str]] = None,
**kwargs: Any,
) -> List[Document]:
"""Return docs selected using the maximal marginal relevance.
Maximal marginal relevance optimizes for similarity to query AND diversity
among selected documents.
Args:
query (str): Text to look up documents similar to.
k (int = 4): Number of Documents to return.
fetch_k (int = 20): Number of Documents to fetch to pass to MMR algorithm.
lambda_mult (float = 0.5): Number between 0 and 1 that determines the degree
of diversity among the results with 0 corresponding
to maximum diversity and 1 to minimum diversity.
Optional.
Returns:
List of Documents selected by maximal marginal relevance.
"""
embedding_vector = self.embedding.embed_query(query)
return self.max_marginal_relevance_search_by_vector(
embedding_vector,
k,
fetch_k,
lambda_mult=lambda_mult,
filter=filter,
)
@classmethod
def from_texts(
cls: Type[ADBVST],
texts: List[str],
embedding: Embeddings,
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
**kwargs: Any,
) -> ADBVST:
"""Create an Astra DB vectorstore from raw texts.
Args:
texts (List[str]): the texts to insert.
embedding (Embeddings): the embedding function to use in the store.
metadatas (Optional[List[dict]]): metadata dicts for the texts.
ids (Optional[List[str]]): ids to associate to the texts.
*Additional arguments*: you can pass any argument that you would
to 'add_texts' and/or to the 'AstraDB' class constructor
(see these methods for details). These arguments will be
routed to the respective methods as they are.
Returns:
an `AstraDb` vectorstore.
"""
known_kwargs = {
"collection_name",
"token",
"api_endpoint",
"astra_db_client",
"namespace",
"metric",
"batch_size",
"bulk_insert_batch_concurrency",
"bulk_insert_overwrite_concurrency",
"bulk_delete_concurrency",
"batch_concurrency",
"overwrite_concurrency",
}
if kwargs:
unknown_kwargs = set(kwargs.keys()) - known_kwargs
if unknown_kwargs:
warnings.warn(
"Method 'from_texts' of AstraDB vector store invoked with "
f"unsupported arguments ({', '.join(sorted(unknown_kwargs))}), "
"which will be ignored."
)
collection_name: str = kwargs["collection_name"]
token = kwargs.get("token")
api_endpoint = kwargs.get("api_endpoint")
astra_db_client = kwargs.get("astra_db_client")
namespace = kwargs.get("namespace")
metric = kwargs.get("metric")
astra_db_store = cls(
embedding=embedding,
collection_name=collection_name,
token=token,
api_endpoint=api_endpoint,
astra_db_client=astra_db_client,
namespace=namespace,
metric=metric,
batch_size=kwargs.get("batch_size"),
bulk_insert_batch_concurrency=kwargs.get("bulk_insert_batch_concurrency"),
bulk_insert_overwrite_concurrency=kwargs.get(
"bulk_insert_overwrite_concurrency"
),
bulk_delete_concurrency=kwargs.get("bulk_delete_concurrency"),
)
astra_db_store.add_texts(
texts=texts,
metadatas=metadatas,
ids=ids,
batch_size=kwargs.get("batch_size"),
batch_concurrency=kwargs.get("batch_concurrency"),
overwrite_concurrency=kwargs.get("overwrite_concurrency"),
)
return astra_db_store
@classmethod
def from_documents(
cls: Type[ADBVST],
documents: List[Document],
embedding: Embeddings,
**kwargs: Any,
) -> ADBVST:
"""Create an Astra DB vectorstore from a document list.
Utility method that defers to 'from_texts' (see that one).
Args: see 'from_texts', except here you have to supply 'documents'
in place of 'texts' and 'metadatas'.
Returns:
an `AstraDB` vectorstore.
"""
return super().from_documents(documents, embedding, **kwargs)

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@@ -0,0 +1,468 @@
"""
Test of Astra DB vector store class `AstraDB`
Required to run this test:
- a recent `astrapy` Python package available
- an Astra DB instance;
- the two environment variables set:
export ASTRA_DB_API_ENDPOINT="https://<DB-ID>-us-east1.apps.astra.datastax.com"
export ASTRA_DB_APPLICATION_TOKEN="AstraCS:........."
- optionally this as well (otherwise defaults are used):
export ASTRA_DB_KEYSPACE="my_keyspace"
"""
import json
import math
import os
from typing import Iterable, List
import pytest
from langchain.embeddings.base import Embeddings
from langchain.schema import Document
from langchain.vectorstores import AstraDB
# Ad-hoc embedding classes:
class SomeEmbeddings(Embeddings):
"""
Turn a sentence into an embedding vector in some way.
Not important how. It is deterministic is all that counts.
"""
def __init__(self, dimension: int) -> None:
self.dimension = dimension
def embed_documents(self, texts: List[str]) -> List[List[float]]:
return [self.embed_query(txt) for txt in texts]
async def aembed_documents(self, texts: List[str]) -> List[List[float]]:
return self.embed_documents(texts)
def embed_query(self, text: str) -> List[float]:
unnormed0 = [ord(c) for c in text[: self.dimension]]
unnormed = (unnormed0 + [1] + [0] * (self.dimension - 1 - len(unnormed0)))[
: self.dimension
]
norm = sum(x * x for x in unnormed) ** 0.5
normed = [x / norm for x in unnormed]
return normed
async def aembed_query(self, text: str) -> List[float]:
return self.embed_query(text)
class ParserEmbeddings(Embeddings):
"""
Parse input texts: if they are json for a List[float], fine.
Otherwise, return all zeros and call it a day.
"""
def __init__(self, dimension: int) -> None:
self.dimension = dimension
def embed_documents(self, texts: List[str]) -> List[List[float]]:
return [self.embed_query(txt) for txt in texts]
async def aembed_documents(self, texts: List[str]) -> List[List[float]]:
return self.embed_documents(texts)
def embed_query(self, text: str) -> List[float]:
try:
vals = json.loads(text)
assert len(vals) == self.dimension
return vals
except Exception:
print(f'[ParserEmbeddings] Returning a moot vector for "{text}"')
return [0.0] * self.dimension
async def aembed_query(self, text: str) -> List[float]:
return self.embed_query(text)
def _has_env_vars() -> bool:
return all(
[
"ASTRA_DB_APPLICATION_TOKEN" in os.environ,
"ASTRA_DB_API_ENDPOINT" in os.environ,
]
)
@pytest.fixture(scope="function")
def store_someemb() -> Iterable[AstraDB]:
emb = SomeEmbeddings(dimension=2)
v_store = AstraDB(
embedding=emb,
collection_name="lc_test_s",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
yield v_store
v_store.delete_collection()
@pytest.fixture(scope="function")
def store_parseremb() -> Iterable[AstraDB]:
emb = ParserEmbeddings(dimension=2)
v_store = AstraDB(
embedding=emb,
collection_name="lc_test_p",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
yield v_store
v_store.delete_collection()
@pytest.mark.requires("astrapy")
@pytest.mark.skipif(not _has_env_vars(), reason="Missing Astra DB env. vars")
class TestAstraDB:
def test_astradb_vectorstore_create_delete(self) -> None:
"""Create and delete."""
emb = SomeEmbeddings(dimension=2)
# creation by passing the connection secrets
v_store = AstraDB(
embedding=emb,
collection_name="lc_test_1",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
v_store.delete_collection()
# Creation by passing a ready-made astrapy client:
from astrapy.db import AstraDB as LibAstraDB
astra_db_client = LibAstraDB(
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
v_store_2 = AstraDB(
embedding=emb,
collection_name="lc_test_2",
astra_db_client=astra_db_client,
)
v_store_2.delete_collection()
def test_astradb_vectorstore_from_x(self) -> None:
"""from_texts and from_documents methods."""
emb = SomeEmbeddings(dimension=2)
# from_texts
v_store = AstraDB.from_texts(
texts=["Hi", "Ho"],
embedding=emb,
collection_name="lc_test_ft",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
assert v_store.similarity_search("Ho", k=1)[0].page_content == "Ho"
v_store.delete_collection()
# from_texts
v_store_2 = AstraDB.from_documents(
[
Document(page_content="Hee"),
Document(page_content="Hoi"),
],
embedding=emb,
collection_name="lc_test_fd",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
assert v_store_2.similarity_search("Hoi", k=1)[0].page_content == "Hoi"
# manual collection delete
v_store_2.delete_collection()
def test_astradb_vectorstore_crud(self, store_someemb: AstraDB) -> None:
"""Basic add/delete/update behaviour."""
res0 = store_someemb.similarity_search("Abc", k=2)
assert res0 == []
# write and check again
store_someemb.add_texts(
texts=["aa", "bb", "cc"],
metadatas=[
{"k": "a", "ord": 0},
{"k": "b", "ord": 1},
{"k": "c", "ord": 2},
],
ids=["a", "b", "c"],
)
res1 = store_someemb.similarity_search("Abc", k=5)
assert {doc.page_content for doc in res1} == {"aa", "bb", "cc"}
# partial overwrite and count total entries
store_someemb.add_texts(
texts=["cc", "dd"],
metadatas=[
{"k": "c_new", "ord": 102},
{"k": "d_new", "ord": 103},
],
ids=["c", "d"],
)
res2 = store_someemb.similarity_search("Abc", k=10)
assert len(res2) == 4
# pick one that was just updated and check its metadata
res3 = store_someemb.similarity_search_with_score_id("cc", k=1)
doc3, score3, id3 = res3[0]
assert doc3.page_content == "cc"
assert doc3.metadata == {"k": "c_new", "ord": 102}
assert score3 > 0.999 # leaving some leeway for approximations...
assert id3 == "c"
# delete and count again
del1_res = store_someemb.delete(["b"])
assert del1_res is True
del2_res = store_someemb.delete(["a", "c", "Z!"])
assert del2_res is False # a non-existing ID was supplied
assert len(store_someemb.similarity_search("xy", k=10)) == 1
# clear store
store_someemb.clear()
assert store_someemb.similarity_search("Abc", k=2) == []
# add_documents with "ids" arg passthrough
store_someemb.add_documents(
[
Document(page_content="vv", metadata={"k": "v", "ord": 204}),
Document(page_content="ww", metadata={"k": "w", "ord": 205}),
],
ids=["v", "w"],
)
assert len(store_someemb.similarity_search("xy", k=10)) == 2
res4 = store_someemb.similarity_search("ww", k=1)
assert res4[0].metadata["ord"] == 205
def test_astradb_vectorstore_mmr(self, store_parseremb: AstraDB) -> None:
"""
MMR testing. We work on the unit circle with angle multiples
of 2*pi/20 and prepare a store with known vectors for a controlled
MMR outcome.
"""
def _v_from_i(i: int, N: int) -> str:
angle = 2 * math.pi * i / N
vector = [math.cos(angle), math.sin(angle)]
return json.dumps(vector)
i_vals = [0, 4, 5, 13]
N_val = 20
store_parseremb.add_texts(
[_v_from_i(i, N_val) for i in i_vals], metadatas=[{"i": i} for i in i_vals]
)
res1 = store_parseremb.max_marginal_relevance_search(
_v_from_i(3, N_val),
k=2,
fetch_k=3,
)
res_i_vals = {doc.metadata["i"] for doc in res1}
assert res_i_vals == {0, 4}
def test_astradb_vectorstore_metadata(self, store_someemb: AstraDB) -> None:
"""Metadata filtering."""
store_someemb.add_documents(
[
Document(
page_content="q",
metadata={"ord": ord("q"), "group": "consonant"},
),
Document(
page_content="w",
metadata={"ord": ord("w"), "group": "consonant"},
),
Document(
page_content="r",
metadata={"ord": ord("r"), "group": "consonant"},
),
Document(
page_content="e",
metadata={"ord": ord("e"), "group": "vowel"},
),
Document(
page_content="i",
metadata={"ord": ord("i"), "group": "vowel"},
),
Document(
page_content="o",
metadata={"ord": ord("o"), "group": "vowel"},
),
]
)
# no filters
res0 = store_someemb.similarity_search("x", k=10)
assert {doc.page_content for doc in res0} == set("qwreio")
# single filter
res1 = store_someemb.similarity_search(
"x",
k=10,
filter={"group": "vowel"},
)
assert {doc.page_content for doc in res1} == set("eio")
# multiple filters
res2 = store_someemb.similarity_search(
"x",
k=10,
filter={"group": "consonant", "ord": ord("q")},
)
assert {doc.page_content for doc in res2} == set("q")
# excessive filters
res3 = store_someemb.similarity_search(
"x",
k=10,
filter={"group": "consonant", "ord": ord("q"), "case": "upper"},
)
assert res3 == []
def test_astradb_vectorstore_similarity_scale(
self, store_parseremb: AstraDB
) -> None:
"""Scale of the similarity scores."""
store_parseremb.add_texts(
texts=[
json.dumps([1, 1]),
json.dumps([-1, -1]),
],
ids=["near", "far"],
)
res1 = store_parseremb.similarity_search_with_score(
json.dumps([0.5, 0.5]),
k=2,
)
scores = [sco for _, sco in res1]
sco_near, sco_far = scores
assert abs(1 - sco_near) < 0.001 and abs(sco_far) < 0.001
def test_astradb_vectorstore_massive_delete(self, store_someemb: AstraDB) -> None:
"""Larger-scale bulk deletes."""
M = 50
texts = [str(i + 1 / 7.0) for i in range(2 * M)]
ids0 = ["doc_%i" % i for i in range(M)]
ids1 = ["doc_%i" % (i + M) for i in range(M)]
ids = ids0 + ids1
store_someemb.add_texts(texts=texts, ids=ids)
# deleting a bunch of these
del_res0 = store_someemb.delete(ids0)
assert del_res0 is True
# deleting the rest plus a fake one
del_res1 = store_someemb.delete(ids1 + ["ghost!"])
assert del_res1 is False # not *all* ids could be deleted...
# nothing left
assert store_someemb.similarity_search("x", k=2 * M) == []
def test_astradb_vectorstore_drop(self) -> None:
"""behaviour of 'delete_collection'."""
emb = SomeEmbeddings(dimension=2)
v_store = AstraDB(
embedding=emb,
collection_name="lc_test_d",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
v_store.add_texts(["huh"])
assert len(v_store.similarity_search("hah", k=10)) == 1
# another instance pointing to the same collection on DB
v_store_kenny = AstraDB(
embedding=emb,
collection_name="lc_test_d",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
)
v_store_kenny.delete_collection()
# dropped on DB, but 'v_store' should have no clue:
with pytest.raises(ValueError):
_ = v_store.similarity_search("hah", k=10)
def test_astradb_vectorstore_custom_params(self) -> None:
"""Custom batch size and concurrency params."""
emb = SomeEmbeddings(dimension=2)
v_store = AstraDB(
embedding=emb,
collection_name="lc_test_c",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
batch_size=17,
bulk_insert_batch_concurrency=13,
bulk_insert_overwrite_concurrency=7,
bulk_delete_concurrency=19,
)
# add_texts
N = 50
texts = [str(i + 1 / 7.0) for i in range(N)]
ids = ["doc_%i" % i for i in range(N)]
v_store.add_texts(texts=texts, ids=ids)
v_store.add_texts(
texts=texts,
ids=ids,
batch_size=19,
batch_concurrency=7,
overwrite_concurrency=13,
)
#
_ = v_store.delete(ids[: N // 2])
_ = v_store.delete(ids[N // 2 :], concurrency=23)
#
v_store.delete_collection()
def test_astradb_vectorstore_metrics(self) -> None:
"""
Different choices of similarity metric.
Both stores (with "cosine" and "euclidea" metrics) contain these two:
- a vector slightly rotated w.r.t query vector
- a vector which is a long multiple of query vector
so, which one is "the closest one" depends on the metric.
"""
emb = ParserEmbeddings(dimension=2)
isq2 = 0.5**0.5
isa = 0.7
isb = (1.0 - isa * isa) ** 0.5
texts = [
json.dumps([isa, isb]),
json.dumps([10 * isq2, 10 * isq2]),
]
ids = [
"rotated",
"scaled",
]
query_text = json.dumps([isq2, isq2])
# creation, population, query - cosine
vstore_cos = AstraDB(
embedding=emb,
collection_name="lc_test_m_c",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
metric="cosine",
)
vstore_cos.add_texts(
texts=texts,
ids=ids,
)
_, _, id_from_cos = vstore_cos.similarity_search_with_score_id(
query_text,
k=1,
)[0]
assert id_from_cos == "scaled"
vstore_cos.delete_collection()
# creation, population, query - euclidean
vstore_euc = AstraDB(
embedding=emb,
collection_name="lc_test_m_e",
token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
namespace=os.environ.get("ASTRA_DB_KEYSPACE"),
metric="euclidean",
)
vstore_euc.add_texts(
texts=texts,
ids=ids,
)
_, _, id_from_euc = vstore_euc.similarity_search_with_score_id(
query_text,
k=1,
)[0]
assert id_from_euc == "rotated"
vstore_euc.delete_collection()

View File

@@ -1125,6 +1125,7 @@ def test_compatible_vectorstore_documentation() -> None:
# These are mentioned in the indexing.ipynb documentation
documented = {
"AnalyticDB",
"AstraDB",
"AzureCosmosDBVectorSearch",
"AwaDB",
"Bagel",

View File

@@ -11,6 +11,7 @@ _EXPECTED = [
"AzureSearch",
"Bagel",
"Cassandra",
"AstraDB",
"Chroma",
"Clarifai",
"Clickhouse",