from __future__ import annotations import asyncio import uuid import warnings from asyncio import Task from concurrent.futures import ThreadPoolExecutor from typing import ( TYPE_CHECKING, Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Type, TypeVar, ) import numpy as np from langchain_core.documents import Document from langchain_core.embeddings import Embeddings from langchain_core.runnables import run_in_executor from langchain_core.runnables.utils import gather_with_concurrency from langchain_core.utils.iter import batch_iterate from langchain_core.vectorstores import VectorStore from langchain_community.vectorstores.utils import maximal_marginal_relevance if TYPE_CHECKING: from astrapy.db import AstraDB as LibAstraDB from astrapy.db import AsyncAstraDB 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 = 16 # 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_community.vectorstores import AstraDB from langchain_community.embeddings.openai import OpenAIEmbeddings embeddings = OpenAIEmbeddings() vectorstore = AstraDB( embedding=embeddings, collection_name="my_store", token="AstraCS:...", api_endpoint="https://-us-east1.apps.astra.datastax.com" ) vectorstore.add_texts(["Giraffes", "All good here"]) results = vectorstore.similarity_search("Everything's ok", k=1) Constructor 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://-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). pre_delete_collection (Optional[bool]): whether to delete the collection before creating it. If False and the collection already exists, the collection will be used as is. A note on concurrency: as a rule of thumb, on a typical client machine it is suggested to keep the quantity bulk_insert_batch_concurrency * bulk_insert_overwrite_concurrency much below 1000 to avoid exhausting the client multithreading/networking resources. The hardcoded defaults are somewhat conservative to meet most machines' specs, but a sensible choice to test may be: bulk_insert_batch_concurrency = 80 bulk_insert_overwrite_concurrency = 10 A bit of experimentation is required to nail the best results here, depending on both the machine/network specs and the expected workload (specifically, how often a write is an update of an existing id). Remember you can pass concurrency settings to individual calls to add_texts and add_documents as well. """ @staticmethod def _filter_to_metadata(filter_dict: Optional[Dict[str, Any]]) -> Dict[str, Any]: if filter_dict is None: return {} else: metadata_filter = {} for k, v in filter_dict.items(): if k and k[0] == "$": if isinstance(v, list): metadata_filter[k] = [AstraDB._filter_to_metadata(f) for f in v] else: metadata_filter[k] = AstraDB._filter_to_metadata(v) # type: ignore[assignment] else: metadata_filter[f"metadata.{k}"] = v return metadata_filter def __init__( self, *, embedding: Embeddings, collection_name: str, token: Optional[str] = None, api_endpoint: Optional[str] = None, astra_db_client: Optional[LibAstraDB] = None, async_astra_db_client: Optional[AsyncAstraDB] = None, 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, pre_delete_collection: bool = False, ) -> None: """ Create an AstraDB vector store object. See class docstring for help. """ try: from astrapy.db import AstraDB as LibAstraDB from astrapy.db import AstraDBCollection except (ImportError, ModuleNotFoundError): raise ImportError( "Could not import a recent astrapy python package. " "Please install it with `pip install --upgrade astrapy`." ) # Conflicting-arg checks: if astra_db_client is not None or async_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' or 'async_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 self.astra_db = astra_db_client self.async_astra_db = async_astra_db_client self.collection = None self.async_collection = None if token and api_endpoint: self.astra_db = LibAstraDB( token=self.token, api_endpoint=self.api_endpoint, namespace=self.namespace, ) try: from astrapy.db import AsyncAstraDB self.async_astra_db = AsyncAstraDB( token=self.token, api_endpoint=self.api_endpoint, namespace=self.namespace, ) except (ImportError, ModuleNotFoundError): pass if self.astra_db is not None: self.collection = AstraDBCollection( collection_name=self.collection_name, astra_db=self.astra_db, ) self.async_setup_db_task: Optional[Task] = None if self.async_astra_db is not None: from astrapy.db import AsyncAstraDBCollection self.async_collection = AsyncAstraDBCollection( collection_name=self.collection_name, astra_db=self.async_astra_db, ) try: self.async_setup_db_task = asyncio.create_task( self._setup_db(pre_delete_collection) ) except RuntimeError: pass if self.async_setup_db_task is None: if not pre_delete_collection: self._provision_collection() else: self.clear() def _ensure_astra_db_client(self): # type: ignore[no-untyped-def] if not self.astra_db: raise ValueError("Missing AstraDB client") async def _setup_db(self, pre_delete_collection: bool) -> None: if pre_delete_collection: await self.async_astra_db.delete_collection( # type: ignore[union-attr] collection_name=self.collection_name, ) await self._aprovision_collection() async def _ensure_db_setup(self) -> None: if self.async_setup_db_task: await self.async_setup_db_task 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 _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( # type: ignore[union-attr] dimension=self._get_embedding_dimension(), collection_name=self.collection_name, metric=self.metric, ) async def _aprovision_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. """ await self.async_astra_db.create_collection( # type: ignore[union-attr] dimension=self._get_embedding_dimension(), collection_name=self.collection_name, metric=self.metric, ) @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.delete_collection() self._provision_collection() async def aclear(self) -> None: """Empty the collection of all its stored entries.""" await self._ensure_db_setup() if not self.async_astra_db: await run_in_executor(None, self.clear) await self.async_collection.delete_many({}) # type: ignore[union-attr] 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. """ self._ensure_astra_db_client() deletion_response = self.collection.delete_one(document_id) # type: ignore[union-attr] return ((deletion_response or {}).get("status") or {}).get( "deletedCount", 0 ) == 1 async def adelete_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. """ await self._ensure_db_setup() if not self.async_collection: return await run_in_executor(None, self.delete_by_document_id, document_id) deletion_response = await self.async_collection.delete_one(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 async def adelete( self, ids: Optional[List[str]] = None, concurrency: Optional[int] = None, **kwargs: Any, ) -> Optional[bool]: """Delete by vector ID or other criteria. Args: ids: List of ids to delete. concurrency (Optional[int]): max number of concurrent delete queries. Defaults to instance-level setting. **kwargs: Other keyword arguments that subclasses might use. Returns: Optional[bool]: True if deletion is successful, False otherwise, None if not implemented. """ if kwargs: warnings.warn( "Method 'adelete' 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.") return all( await gather_with_concurrency( concurrency, *[self.adelete_by_document_id(doc_id) for doc_id in ids] ) ) 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._ensure_astra_db_client() self.astra_db.delete_collection( # type: ignore[union-attr] collection_name=self.collection_name, ) async def adelete_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. """ await self._ensure_db_setup() if not self.async_astra_db: await run_in_executor(None, self.delete_collection) await self.async_astra_db.delete_collection( # type: ignore[union-attr] collection_name=self.collection_name, ) @staticmethod def _get_documents_to_insert( texts: Iterable[str], embedding_vectors: List[List[float]], metadatas: Optional[List[dict]] = None, ids: Optional[List[str]] = None, ) -> List[DocDict]: if ids is None: ids = [uuid.uuid4().hex for _ in texts] if metadatas is None: metadatas = [{} for _ in 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] return uniqued_documents_to_insert @staticmethod def _get_missing_from_batch( document_batch: List[DocDict], insert_result: Dict[str, Any] ) -> Tuple[List[str], List[DocDict]]: if "status" not in insert_result: raise ValueError( f"API Exception while running bulk insertion: {str(insert_result)}" ) batch_inserted = insert_result["status"]["insertedIds"] # estimation of the preexisting documents that failed missed_inserted_ids = {document["_id"] for document in document_batch} - set( batch_inserted ) errors = insert_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 ] return batch_inserted, missing_from_batch 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. A note on metadata: there are constraints on the allowed field names in this dictionary, coming from the underlying Astra DB API. For instance, the `$` (dollar sign) cannot be used in the dict keys. See this document for details: docs.datastax.com/en/astra-serverless/docs/develop/dev-with-json.html 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." ) self._ensure_astra_db_client() embedding_vectors = self.embedding.embed_documents(list(texts)) documents_to_insert = self._get_documents_to_insert( texts, embedding_vectors, metadatas, ids ) def _handle_batch(document_batch: List[DocDict]) -> List[str]: im_result = self.collection.insert_many( # type: ignore[union-attr] documents=document_batch, options={"ordered": False}, partial_failures_allowed=True, ) batch_inserted, missing_from_batch = self._get_missing_from_batch( document_batch, im_result ) def _handle_missing_document(missing_document: DocDict) -> str: replacement_result = self.collection.find_one_and_replace( # type: ignore[union-attr] 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, ) ) return batch_inserted + batch_replaced _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, documents_to_insert, ), ) return [iid for id_list in all_ids_nested for iid in id_list] async def aadd_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 concurrent batch insertions. Defaults to instance-level setting if not provided. overwrite_concurrency (Optional[int]): number of concurrent API calls to process pre-existing documents in each batch. Defaults to instance-level setting if not provided. A note on metadata: there are constraints on the allowed field names in this dictionary, coming from the underlying Astra DB API. For instance, the `$` (dollar sign) cannot be used in the dict keys. See this document for details: docs.datastax.com/en/astra-serverless/docs/develop/dev-with-json.html Returns: List[str]: List of ids of the added texts. """ await self._ensure_db_setup() if not self.async_collection: await super().aadd_texts( texts, metadatas, ids=ids, batch_size=batch_size, batch_concurrency=batch_concurrency, overwrite_concurrency=overwrite_concurrency, ) if kwargs: warnings.warn( "Method 'aadd_texts' of AstraDB vector store invoked with " f"unsupported arguments ({', '.join(sorted(kwargs.keys()))}), " "which will be ignored." ) embedding_vectors = await self.embedding.aembed_documents(list(texts)) documents_to_insert = self._get_documents_to_insert( texts, embedding_vectors, metadatas, ids ) async def _handle_batch(document_batch: List[DocDict]) -> List[str]: im_result = await self.async_collection.insert_many( # type: ignore[union-attr] documents=document_batch, options={"ordered": False}, partial_failures_allowed=True, ) batch_inserted, missing_from_batch = self._get_missing_from_batch( document_batch, im_result ) async def _handle_missing_document(missing_document: DocDict) -> str: replacement_result = await self.async_collection.find_one_and_replace( # type: ignore[union-attr] 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 ) batch_replaced = await gather_with_concurrency( _u_max_workers, *[_handle_missing_document(doc) for doc in missing_from_batch], ) return batch_inserted + batch_replaced _b_max_workers = batch_concurrency or self.bulk_insert_batch_concurrency all_ids_nested = await gather_with_concurrency( _b_max_workers, *[ _handle_batch(batch) for batch in batch_iterate( batch_size or self.batch_size, documents_to_insert, ) ], ) return [iid for id_list in all_ids_nested for iid in id_list] def similarity_search_with_score_id_by_vector( self, embedding: List[float], k: int = 4, filter: Optional[Dict[str, Any]] = 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. """ self._ensure_astra_db_client() metadata_parameter = self._filter_to_metadata(filter) # hits = list( self.collection.paginated_find( # type: ignore[union-attr] filter=metadata_parameter, sort={"$vector": embedding}, options={"limit": k, "includeSimilarity": True}, projection={ "_id": 1, "content": 1, "metadata": 1, }, ) ) # return [ ( Document( page_content=hit["content"], metadata=hit["metadata"], ), hit["$similarity"], hit["_id"], ) for hit in hits ] async def asimilarity_search_with_score_id_by_vector( self, embedding: List[float], k: int = 4, filter: Optional[Dict[str, Any]] = 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. """ await self._ensure_db_setup() if not self.async_collection: return await run_in_executor( None, self.asimilarity_search_with_score_id_by_vector, # type: ignore[arg-type] embedding, k, filter, ) metadata_parameter = self._filter_to_metadata(filter) # return [ ( Document( page_content=hit["content"], metadata=hit["metadata"], ), hit["$similarity"], hit["_id"], ) async for hit in self.async_collection.paginated_find( filter=metadata_parameter, sort={"$vector": embedding}, options={"limit": k, "includeSimilarity": True}, projection={ "_id": 1, "content": 1, "metadata": 1, }, ) ] def similarity_search_with_score_id( self, query: str, k: int = 4, filter: Optional[Dict[str, Any]] = 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, ) async def asimilarity_search_with_score_id( self, query: str, k: int = 4, filter: Optional[Dict[str, Any]] = None, ) -> List[Tuple[Document, float, str]]: embedding_vector = await self.embedding.aembed_query(query) return await self.asimilarity_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, Any]] = 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, ) ] async def asimilarity_search_with_score_by_vector( self, embedding: List[float], k: int = 4, filter: Optional[Dict[str, Any]] = 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 await self.asimilarity_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, Any]] = None, **kwargs: Any, ) -> List[Document]: embedding_vector = self.embedding.embed_query(query) return self.similarity_search_by_vector( embedding_vector, k, filter=filter, ) async def asimilarity_search( self, query: str, k: int = 4, filter: Optional[Dict[str, Any]] = None, **kwargs: Any, ) -> List[Document]: embedding_vector = await self.embedding.aembed_query(query) return await self.asimilarity_search_by_vector( embedding_vector, k, filter=filter, ) def similarity_search_by_vector( self, embedding: List[float], k: int = 4, filter: Optional[Dict[str, Any]] = None, **kwargs: Any, ) -> List[Document]: return [ doc for doc, _ in self.similarity_search_with_score_by_vector( embedding, k, filter=filter, ) ] async def asimilarity_search_by_vector( self, embedding: List[float], k: int = 4, filter: Optional[Dict[str, Any]] = None, **kwargs: Any, ) -> List[Document]: return [ doc for doc, _ in await self.asimilarity_search_with_score_by_vector( embedding, k, filter=filter, ) ] def similarity_search_with_score( self, query: str, k: int = 4, filter: Optional[Dict[str, Any]] = 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, ) async def asimilarity_search_with_score( self, query: str, k: int = 4, filter: Optional[Dict[str, Any]] = None, ) -> List[Tuple[Document, float]]: embedding_vector = await self.embedding.aembed_query(query) return await self.asimilarity_search_with_score_by_vector( embedding_vector, k, filter=filter, ) @staticmethod def _get_mmr_hits(embedding, k, lambda_mult, prefetch_hits): # type: ignore[no-untyped-def] mmr_chosen_indices = maximal_marginal_relevance( np.array(embedding, dtype=np.float32), [prefetch_hit["$vector"] for prefetch_hit in prefetch_hits], k=k, lambda_mult=lambda_mult, ) mmr_hits = [ prefetch_hit for prefetch_index, prefetch_hit in enumerate(prefetch_hits) if prefetch_index in mmr_chosen_indices ] return [ Document( page_content=hit["content"], metadata=hit["metadata"], ) for hit in mmr_hits ] def max_marginal_relevance_search_by_vector( self, embedding: List[float], k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, filter: Optional[Dict[str, Any]] = None, **kwargs: Any, ) -> List[Document]: """Return docs selected using the maximal marginal relevance. Maximal marginal relevance optimizes for similarity to query AND diversity among selected documents. Args: embedding: Embedding to look up documents similar to. k: Number of Documents to return. fetch_k: Number of Documents to fetch to pass to MMR algorithm. lambda_mult: Number between 0 and 1 that determines the degree of diversity among the results with 0 corresponding to maximum diversity and 1 to minimum diversity. Returns: List of Documents selected by maximal marginal relevance. """ self._ensure_astra_db_client() metadata_parameter = self._filter_to_metadata(filter) prefetch_hits = list( self.collection.paginated_find( # type: ignore[union-attr] filter=metadata_parameter, sort={"$vector": embedding}, options={"limit": fetch_k, "includeSimilarity": True}, projection={ "_id": 1, "content": 1, "metadata": 1, "$vector": 1, }, ) ) return self._get_mmr_hits(embedding, k, lambda_mult, prefetch_hits) async def amax_marginal_relevance_search_by_vector( self, embedding: List[float], k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, filter: Optional[Dict[str, Any]] = None, **kwargs: Any, ) -> List[Document]: """Return docs selected using the maximal marginal relevance. Maximal marginal relevance optimizes for similarity to query AND diversity among selected documents. Args: embedding: Embedding to look up documents similar to. k: Number of Documents to return. fetch_k: Number of Documents to fetch to pass to MMR algorithm. lambda_mult: Number between 0 and 1 that determines the degree of diversity among the results with 0 corresponding to maximum diversity and 1 to minimum diversity. Returns: List of Documents selected by maximal marginal relevance. """ await self._ensure_db_setup() if not self.async_collection: return await run_in_executor( None, self.max_marginal_relevance_search_by_vector, embedding, k, fetch_k, lambda_mult, filter, **kwargs, ) metadata_parameter = self._filter_to_metadata(filter) prefetch_hits = [ hit async for hit in self.async_collection.paginated_find( filter=metadata_parameter, sort={"$vector": embedding}, options={"limit": fetch_k, "includeSimilarity": True}, projection={ "_id": 1, "content": 1, "metadata": 1, "$vector": 1, }, ) ] return self._get_mmr_hits(embedding, k, lambda_mult, prefetch_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, Any]] = 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, ) async def amax_marginal_relevance_search( self, query: str, k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, filter: Optional[Dict[str, Any]] = 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 = await self.embedding.aembed_query(query) return await self.amax_marginal_relevance_search_by_vector( embedding_vector, k, fetch_k, lambda_mult=lambda_mult, filter=filter, ) @classmethod def _from_kwargs( cls: Type[ADBVST], embedding: Embeddings, **kwargs: Any, ) -> ADBVST: known_kwargs = { "collection_name", "token", "api_endpoint", "astra_db_client", "async_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") async_astra_db_client = kwargs.get("async_astra_db_client") namespace = kwargs.get("namespace") metric = kwargs.get("metric") return cls( embedding=embedding, 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, 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"), ) @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. """ astra_db_store = AstraDB._from_kwargs(embedding, **kwargs) 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 # type: ignore[return-value] @classmethod async def afrom_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. """ astra_db_store = AstraDB._from_kwargs(embedding, **kwargs) await astra_db_store.aadd_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 # type: ignore[return-value] @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)