from __future__ import annotations
import logging
import uuid
import warnings
from typing import (
TYPE_CHECKING,
Any,
Callable,
Iterable,
List,
Optional,
Tuple,
TypeVar,
Union,
)
import numpy as np
from langchain_core.documents import Document
from langchain_core.embeddings import Embeddings
from langchain_core.vectorstores import VectorStore
from langchain_community.vectorstores.utils import (
DistanceStrategy,
maximal_marginal_relevance,
)
if TYPE_CHECKING:
from aerospike_vector_search import Client
from aerospike_vector_search.types import Neighbor, VectorDistanceMetric
logger = logging.getLogger(__name__)
def _import_aerospike() -> Any:
try:
from aerospike_vector_search import Client
except ImportError as e:
raise ImportError(
"Could not import aerospike_vector_search python package. "
"Please install it with `pip install aerospike_vector`."
) from e
return Client
AVST = TypeVar("AVST", bound="Aerospike")
[docs]
class Aerospike(VectorStore):
"""`Aerospike` vector store.
To use, you should have the ``aerospike_vector_search`` python package installed.
"""
[docs]
def __init__(
self,
client: Client,
embedding: Union[Embeddings, Callable],
namespace: str,
index_name: Optional[str] = None,
vector_key: str = "_vector",
text_key: str = "_text",
id_key: str = "_id",
set_name: Optional[str] = None,
distance_strategy: Optional[
Union[DistanceStrategy, VectorDistanceMetric]
] = DistanceStrategy.EUCLIDEAN_DISTANCE,
):
"""Initialize with Aerospike client.
Args:
client: Aerospike client.
embedding: Embeddings object or Callable (deprecated) to embed text.
namespace: Namespace to use for storing vectors. This should match
index_name: Name of the index previously created in Aerospike. This
vector_key: Key to use for vector in metadata. This should match the
key used during index creation.
text_key: Key to use for text in metadata.
id_key: Key to use for id in metadata.
set_name: Default set name to use for storing vectors.
distance_strategy: Distance strategy to use for similarity search
This should match the distance strategy used during index creation.
"""
aerospike = _import_aerospike()
if not isinstance(embedding, Embeddings):
warnings.warn(
"Passing in `embedding` as a Callable is deprecated. Please pass in an"
" Embeddings object instead."
)
if not isinstance(client, aerospike):
raise ValueError(
f"client should be an instance of aerospike_vector_search.Client, "
f"got {type(client)}"
)
self._client = client
self._embedding = embedding
self._text_key = text_key
self._vector_key = vector_key
self._id_key = id_key
self._index_name = index_name
self._namespace = namespace
self._set_name = set_name
self._distance_strategy = self.convert_distance_strategy(distance_strategy)
@property
def embeddings(self) -> Optional[Embeddings]:
"""Access the query embedding object if available."""
if isinstance(self._embedding, Embeddings):
return self._embedding
return None
def _embed_documents(self, texts: Iterable[str]) -> List[List[float]]:
"""Embed search docs."""
if isinstance(self._embedding, Embeddings):
return self._embedding.embed_documents(list(texts))
return [self._embedding(t) for t in texts]
def _embed_query(self, text: str) -> List[float]:
"""Embed query text."""
if isinstance(self._embedding, Embeddings):
return self._embedding.embed_query(text)
return self._embedding(text)
[docs]
@staticmethod
def convert_distance_strategy(
distance_strategy: Union[VectorDistanceMetric, DistanceStrategy],
) -> DistanceStrategy:
"""
Convert Aerospikes distance strategy to langchains DistanceStrategy
enum. This is a convenience method to allow users to pass in the same
distance metric used to create the index.
"""
from aerospike_vector_search.types import VectorDistanceMetric
if isinstance(distance_strategy, DistanceStrategy):
return distance_strategy
if distance_strategy == VectorDistanceMetric.COSINE:
return DistanceStrategy.COSINE
if distance_strategy == VectorDistanceMetric.DOT_PRODUCT:
return DistanceStrategy.DOT_PRODUCT
if distance_strategy == VectorDistanceMetric.SQUARED_EUCLIDEAN:
return DistanceStrategy.EUCLIDEAN_DISTANCE
raise ValueError(
"Unknown distance strategy, must be cosine, dot_product" ", or euclidean"
)
[docs]
def add_texts(
self,
texts: Iterable[str],
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
set_name: Optional[str] = None,
embedding_chunk_size: int = 1000,
index_name: Optional[str] = None,
wait_for_index: bool = True,
**kwargs: Any,
) -> List[str]:
"""Run more texts through the embeddings and add to the vectorstore.
Args:
texts: Iterable of strings to add to the vectorstore.
metadatas: Optional list of metadatas associated with the texts.
ids: Optional list of ids to associate with the texts.
set_name: Optional aerospike set name to add the texts to.
batch_size: Batch size to use when adding the texts to the vectorstore.
embedding_chunk_size: Chunk size to use when embedding the texts.
index_name: Optional aerospike index name used for waiting for index
completion. If not provided, the default index_name will be used.
wait_for_index: If True, wait for the all the texts to be indexed
before returning. Requires index_name to be provided. Defaults
to True.
kwargs: Additional keyword arguments to pass to the client upsert call.
Returns:
List of ids from adding the texts into the vectorstore.
"""
if set_name is None:
set_name = self._set_name
if index_name is None:
index_name = self._index_name
if wait_for_index and index_name is None:
raise ValueError("if wait_for_index is True, index_name must be provided")
texts = list(texts)
ids = ids or [str(uuid.uuid4()) for _ in texts]
# We need to shallow copy so that we can add the vector and text keys
if metadatas:
metadatas = [m.copy() for m in metadatas]
else:
metadatas = metadatas or [{} for _ in texts]
for i in range(0, len(texts), embedding_chunk_size):
chunk_texts = texts[i : i + embedding_chunk_size]
chunk_ids = ids[i : i + embedding_chunk_size]
chunk_metadatas = metadatas[i : i + embedding_chunk_size]
embeddings = self._embed_documents(chunk_texts)
for metadata, embedding, text in zip(
chunk_metadatas, embeddings, chunk_texts
):
metadata[self._vector_key] = embedding
metadata[self._text_key] = text
for id, metadata in zip(chunk_ids, chunk_metadatas):
metadata[self._id_key] = id
self._client.upsert(
namespace=self._namespace,
key=id,
set_name=set_name,
record_data=metadata,
**kwargs,
)
if wait_for_index:
self._client.wait_for_index_completion(
namespace=self._namespace,
name=index_name,
)
return ids
[docs]
def delete(
self,
ids: Optional[List[str]] = None,
set_name: Optional[str] = None,
**kwargs: Any,
) -> Optional[bool]:
"""Delete by vector ID or other criteria.
Args:
ids: List of ids to delete.
**kwargs: Other keyword arguments to pass to client delete call.
Returns:
Optional[bool]: True if deletion is successful,
False otherwise, None if not implemented.
"""
from aerospike_vector_search import AVSServerError
if ids:
for id in ids:
try:
self._client.delete(
namespace=self._namespace,
key=id,
set_name=set_name,
**kwargs,
)
except AVSServerError:
return False
return True
[docs]
def similarity_search_with_score(
self,
query: str,
k: int = 4,
metadata_keys: Optional[List[str]] = None,
index_name: Optional[str] = None,
**kwargs: Any,
) -> List[Tuple[Document, float]]:
"""Return aerospike documents most similar to query, along with scores.
Args:
query: Text to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
metadata_keys: List of metadata keys to return with the documents.
If None, all metadata keys will be returned. Defaults to None.
index_name: Name of the index to search. Overrides the default
index_name.
kwargs: Additional keyword arguments to pass to the search method.
Returns:
List of Documents most similar to the query and associated scores.
"""
return self.similarity_search_by_vector_with_score(
self._embed_query(query),
k=k,
metadata_keys=metadata_keys,
index_name=index_name,
**kwargs,
)
[docs]
def similarity_search_by_vector_with_score(
self,
embedding: List[float],
k: int = 4,
metadata_keys: Optional[List[str]] = None,
index_name: Optional[str] = None,
**kwargs: Any,
) -> List[Tuple[Document, float]]:
"""Return aerospike documents most similar to embedding, along with scores.
Args:
embedding: Embedding to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
metadata_keys: List of metadata keys to return with the documents.
If None, all metadata keys will be returned. Defaults to None.
index_name: Name of the index to search. Overrides the default
index_name.
kwargs: Additional keyword arguments to pass to the client
vector_search method.
Returns:
List of Documents most similar to the query and associated scores.
"""
docs = []
if metadata_keys and self._text_key not in metadata_keys:
metadata_keys = [self._text_key] + metadata_keys
if index_name is None:
index_name = self._index_name
if index_name is None:
raise ValueError("index_name must be provided")
results: list[Neighbor] = self._client.vector_search(
index_name=index_name,
namespace=self._namespace,
query=embedding,
limit=k,
field_names=metadata_keys,
**kwargs,
)
for result in results:
metadata = result.fields
if self._text_key in metadata:
text = metadata.pop(self._text_key)
score = result.distance
docs.append((Document(page_content=text, metadata=metadata), score))
else:
logger.warning(
f"Found document with no `{self._text_key}` key. Skipping."
)
continue
return docs
[docs]
def similarity_search_by_vector(
self,
embedding: List[float],
k: int = 4,
metadata_keys: Optional[List[str]] = None,
index_name: Optional[str] = None,
**kwargs: Any,
) -> List[Document]:
"""Return docs most similar to embedding vector.
Args:
embedding: Embedding to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
metadata_keys: List of metadata keys to return with the documents.
If None, all metadata keys will be returned. Defaults to None.
index_name: Name of the index to search. Overrides the default
index_name.
kwargs: Additional keyword arguments to pass to the search method.
Returns:
List of Documents most similar to the query vector.
"""
return [
doc
for doc, _ in self.similarity_search_by_vector_with_score(
embedding,
k=k,
metadata_keys=metadata_keys,
index_name=index_name,
**kwargs,
)
]
[docs]
def similarity_search(
self,
query: str,
k: int = 4,
metadata_keys: Optional[List[str]] = None,
index_name: Optional[str] = None,
**kwargs: Any,
) -> List[Document]:
"""Return aerospike documents most similar to query.
Args:
query: Text to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
metadata_keys: List of metadata keys to return with the documents.
If None, all metadata keys will be returned. Defaults to None.
index_name: Optional name of the index to search. Overrides the
default index_name.
Returns:
List of Documents most similar to the query and score for each
"""
docs_and_scores = self.similarity_search_with_score(
query, k=k, metadata_keys=metadata_keys, index_name=index_name, **kwargs
)
return [doc for doc, _ in docs_and_scores]
def _select_relevance_score_fn(self) -> Callable[[float], float]:
"""
The 'correct' relevance function
may differ depending on a few things, including:
- the distance / similarity metric used by the VectorStore
- the scale of your embeddings (OpenAI's are unit normed. Many others are not!)
- embedding dimensionality
- etc.
0 is dissimilar, 1 is similar.
Aerospike's relevance_fn assume euclidean and dot product embeddings are
normalized to unit norm.
"""
if self._distance_strategy == DistanceStrategy.COSINE:
return self._cosine_relevance_score_fn
elif self._distance_strategy == DistanceStrategy.DOT_PRODUCT:
return self._max_inner_product_relevance_score_fn
elif self._distance_strategy == DistanceStrategy.EUCLIDEAN_DISTANCE:
return self._euclidean_relevance_score_fn
else:
raise ValueError(
"Unknown distance strategy, must be cosine, dot_product"
", or euclidean"
)
@staticmethod
def _cosine_relevance_score_fn(score: float) -> float:
"""Aerospike returns cosine distance scores between [0,2]
0 is dissimilar, 1 is similar.
"""
return 1 - (score / 2)
[docs]
def max_marginal_relevance_search_by_vector(
self,
embedding: List[float],
k: int = 4,
fetch_k: int = 20,
lambda_mult: float = 0.5,
metadata_keys: Optional[List[str]] = None,
index_name: Optional[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. Defaults to 4.
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. Defaults to 0.5.
metadata_keys: List of metadata keys to return with the documents.
If None, all metadata keys will be returned. Defaults to None.
index_name: Optional name of the index to search. Overrides the
default index_name.
Returns:
List of Documents selected by maximal marginal relevance.
"""
if metadata_keys and self._vector_key not in metadata_keys:
metadata_keys = [self._vector_key] + metadata_keys
docs = self.similarity_search_by_vector(
embedding,
k=fetch_k,
metadata_keys=metadata_keys,
index_name=index_name,
**kwargs,
)
mmr_selected = maximal_marginal_relevance(
np.array([embedding], dtype=np.float32),
[doc.metadata[self._vector_key] for doc in docs],
k=k,
lambda_mult=lambda_mult,
)
if metadata_keys and self._vector_key in metadata_keys:
for i in mmr_selected:
docs[i].metadata.pop(self._vector_key)
return [docs[i] for i in mmr_selected]
[docs]
def max_marginal_relevance_search(
self,
query: str,
k: int = 4,
fetch_k: int = 20,
lambda_mult: float = 0.5,
metadata_keys: Optional[List[str]] = None,
index_name: Optional[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: Text to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
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.
Defaults to 0.5.
index_name: Name of the index to search.
Returns:
List of Documents selected by maximal marginal relevance.
"""
embedding = self._embed_query(query)
return self.max_marginal_relevance_search_by_vector(
embedding,
k,
fetch_k,
lambda_mult,
metadata_keys=metadata_keys,
index_name=index_name,
**kwargs,
)
[docs]
@classmethod
def from_texts(
cls,
texts: List[str],
embedding: Embeddings,
metadatas: Optional[List[dict]] = None,
client: Client = None,
namespace: str = "test",
index_name: Optional[str] = None,
ids: Optional[List[str]] = None,
embeddings_chunk_size: int = 1000,
client_kwargs: Optional[dict] = None,
**kwargs: Any,
) -> Aerospike:
"""
This is a user friendly interface that:
1. Embeds text.
2. Converts the texts into documents.
3. Adds the documents to a provided Aerospike index
This is intended to be a quick way to get started.
Example:
.. code-block:: python
from langchain_community.vectorstores import Aerospike
from langchain_openai import OpenAIEmbeddings
from aerospike_vector_search import Client, HostPort
client = Client(seeds=HostPort(host="localhost", port=5000))
aerospike = Aerospike.from_texts(
["foo", "bar", "baz"],
embedder,
client,
"namespace",
index_name="index",
vector_key="vector",
distance_strategy=MODEL_DISTANCE_CALC,
)
"""
aerospike = cls(
client,
embedding,
namespace,
**kwargs,
)
aerospike.add_texts(
texts,
metadatas=metadatas,
ids=ids,
index_name=index_name,
embedding_chunk_size=embeddings_chunk_size,
**(client_kwargs or {}),
)
return aerospike
