"""Wrapper around TileDB vector database."""
from __future__ import annotations
import pickle
import random
import sys
from typing import Any, Dict, Iterable, List, Mapping, Optional, Tuple
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 maximal_marginal_relevance
INDEX_METRICS = frozenset(["euclidean"])
DEFAULT_METRIC = "euclidean"
DOCUMENTS_ARRAY_NAME = "documents"
VECTOR_INDEX_NAME = "vectors"
MAX_UINT64 = np.iinfo(np.dtype("uint64")).max
MAX_FLOAT_32 = np.finfo(np.dtype("float32")).max
MAX_FLOAT = sys.float_info.max
[docs]def dependable_tiledb_import() -> Any:
"""Import tiledb-vector-search if available, otherwise raise error."""
try:
import tiledb as tiledb
import tiledb.vector_search as tiledb_vs
except ImportError:
raise ValueError(
"Could not import tiledb-vector-search python package. "
"Please install it with `conda install -c tiledb tiledb-vector-search` "
"or `pip install tiledb-vector-search`"
)
return tiledb_vs, tiledb
[docs]def get_vector_index_uri_from_group(group: Any) -> str:
return group[VECTOR_INDEX_NAME].uri
[docs]def get_documents_array_uri_from_group(group: Any) -> str:
return group[DOCUMENTS_ARRAY_NAME].uri
[docs]def get_vector_index_uri(uri: str) -> str:
return f"{uri}/{VECTOR_INDEX_NAME}"
[docs]def get_documents_array_uri(uri: str) -> str:
return f"{uri}/{DOCUMENTS_ARRAY_NAME}"
[docs]class TileDB(VectorStore):
"""Wrapper around TileDB vector database.
To use, you should have the ``tiledb-vector-search`` python package installed.
Example:
.. code-block:: python
from langchain_community import TileDB
embeddings = OpenAIEmbeddings()
db = TileDB(embeddings, index_uri, metric)
"""
[docs] def __init__(
self,
embedding: Embeddings,
index_uri: str,
metric: str,
*,
vector_index_uri: str = "",
docs_array_uri: str = "",
config: Optional[Mapping[str, Any]] = None,
timestamp: Any = None,
**kwargs: Any,
):
"""Initialize with necessary components."""
self.embedding = embedding
self.embedding_function = embedding.embed_query
self.index_uri = index_uri
self.metric = metric
self.config = config
tiledb_vs, tiledb = dependable_tiledb_import()
with tiledb.scope_ctx(ctx_or_config=config):
index_group = tiledb.Group(self.index_uri, "r")
self.vector_index_uri = (
vector_index_uri
if vector_index_uri != ""
else get_vector_index_uri_from_group(index_group)
)
self.docs_array_uri = (
docs_array_uri
if docs_array_uri != ""
else get_documents_array_uri_from_group(index_group)
)
index_group.close()
group = tiledb.Group(self.vector_index_uri, "r")
self.index_type = group.meta.get("index_type")
group.close()
self.timestamp = timestamp
if self.index_type == "FLAT":
self.vector_index = tiledb_vs.flat_index.FlatIndex(
uri=self.vector_index_uri,
config=self.config,
timestamp=self.timestamp,
**kwargs,
)
elif self.index_type == "IVF_FLAT":
self.vector_index = tiledb_vs.ivf_flat_index.IVFFlatIndex(
uri=self.vector_index_uri,
config=self.config,
timestamp=self.timestamp,
**kwargs,
)
@property
def embeddings(self) -> Optional[Embeddings]:
return self.embedding
[docs] def process_index_results(
self,
ids: List[int],
scores: List[float],
*,
k: int = 4,
filter: Optional[Dict[str, Any]] = None,
score_threshold: float = MAX_FLOAT,
) -> List[Tuple[Document, float]]:
"""Turns TileDB results into a list of documents and scores.
Args:
ids: List of indices of the documents in the index.
scores: List of distances of the documents in the index.
k: Number of Documents to return. Defaults to 4.
filter (Optional[Dict[str, Any]]): Filter by metadata. Defaults to None.
score_threshold: Optional, a floating point value to filter the
resulting set of retrieved docs
Returns:
List of Documents and scores.
"""
tiledb_vs, tiledb = dependable_tiledb_import()
docs = []
docs_array = tiledb.open(
self.docs_array_uri, "r", timestamp=self.timestamp, config=self.config
)
for idx, score in zip(ids, scores):
if idx == 0 and score == 0:
continue
if idx == MAX_UINT64 and score == MAX_FLOAT_32:
continue
doc = docs_array[idx]
if doc is None or len(doc["text"]) == 0:
raise ValueError(f"Could not find document for id {idx}, got {doc}")
pickled_metadata = doc.get("metadata")
result_doc = Document(page_content=str(doc["text"][0]))
if pickled_metadata is not None:
metadata = pickle.loads(
np.array(pickled_metadata.tolist()).astype(np.uint8).tobytes()
)
result_doc.metadata = metadata
if filter is not None:
filter = {
key: [value] if not isinstance(value, list) else value
for key, value in filter.items()
}
if all(
result_doc.metadata.get(key) in value
for key, value in filter.items()
):
docs.append((result_doc, score))
else:
docs.append((result_doc, score))
docs_array.close()
docs = [(doc, score) for doc, score in docs if score <= score_threshold]
return docs[:k]
[docs] def similarity_search_with_score_by_vector(
self,
embedding: List[float],
*,
k: int = 4,
filter: Optional[Dict[str, Any]] = None,
fetch_k: int = 20,
**kwargs: Any,
) -> List[Tuple[Document, float]]:
"""Return docs most similar to query.
Args:
embedding: Embedding vector to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
filter (Optional[Dict[str, Any]]): Filter by metadata. Defaults to None.
fetch_k: (Optional[int]) Number of Documents to fetch before filtering.
Defaults to 20.
**kwargs: kwargs to be passed to similarity search. Can include:
nprobe: Optional, number of partitions to check if using IVF_FLAT index
score_threshold: Optional, a floating point value to filter the
resulting set of retrieved docs
Returns:
List of documents most similar to the query text and distance
in float for each. Lower score represents more similarity.
"""
if "score_threshold" in kwargs:
score_threshold = kwargs.pop("score_threshold")
else:
score_threshold = MAX_FLOAT
d, i = self.vector_index.query(
np.array([np.array(embedding).astype(np.float32)]).astype(np.float32),
k=k if filter is None else fetch_k,
**kwargs,
)
return self.process_index_results(
ids=i[0], scores=d[0], filter=filter, k=k, score_threshold=score_threshold
)
[docs] def similarity_search_with_score(
self,
query: str,
*,
k: int = 4,
filter: Optional[Dict[str, Any]] = None,
fetch_k: int = 20,
**kwargs: Any,
) -> List[Tuple[Document, float]]:
"""Return docs most similar to query.
Args:
query: Text to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
fetch_k: (Optional[int]) Number of Documents to fetch before filtering.
Defaults to 20.
Returns:
List of documents most similar to the query text with
Distance as float. Lower score represents more similarity.
"""
embedding = self.embedding_function(query)
docs = self.similarity_search_with_score_by_vector(
embedding,
k=k,
filter=filter,
fetch_k=fetch_k,
**kwargs,
)
return docs
[docs] def similarity_search_by_vector(
self,
embedding: List[float],
k: int = 4,
filter: Optional[Dict[str, Any]] = None,
fetch_k: int = 20,
**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.
filter (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
fetch_k: (Optional[int]) Number of Documents to fetch before filtering.
Defaults to 20.
Returns:
List of Documents most similar to the embedding.
"""
docs_and_scores = self.similarity_search_with_score_by_vector(
embedding,
k=k,
filter=filter,
fetch_k=fetch_k,
**kwargs,
)
return [doc for doc, _ in docs_and_scores]
[docs] def similarity_search(
self,
query: str,
k: int = 4,
filter: Optional[Dict[str, Any]] = None,
fetch_k: int = 20,
**kwargs: Any,
) -> List[Document]:
"""Return docs most similar to query.
Args:
query: Text to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
filter: (Optional[Dict[str, str]]): Filter by metadata. Defaults to None.
fetch_k: (Optional[int]) Number of Documents to fetch before filtering.
Defaults to 20.
Returns:
List of Documents most similar to the query.
"""
docs_and_scores = self.similarity_search_with_score(
query, k=k, filter=filter, fetch_k=fetch_k, **kwargs
)
return [doc for doc, _ in docs_and_scores]
[docs] def max_marginal_relevance_search_with_score_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[Tuple[Document, float]]:
"""Return docs and their similarity scores 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 before filtering 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.
Returns:
List of Documents and similarity scores selected by maximal marginal
relevance and score for each.
"""
if "score_threshold" in kwargs:
score_threshold = kwargs.pop("score_threshold")
else:
score_threshold = MAX_FLOAT
scores, indices = self.vector_index.query(
np.array([np.array(embedding).astype(np.float32)]).astype(np.float32),
k=fetch_k if filter is None else fetch_k * 2,
**kwargs,
)
results = self.process_index_results(
ids=indices[0],
scores=scores[0],
filter=filter,
k=fetch_k if filter is None else fetch_k * 2,
score_threshold=score_threshold,
)
embeddings = [
self.embedding.embed_documents([doc.page_content])[0] for doc, _ in results
]
mmr_selected = maximal_marginal_relevance(
np.array([embedding], dtype=np.float32),
embeddings,
k=k,
lambda_mult=lambda_mult,
)
docs_and_scores = []
for i in mmr_selected:
docs_and_scores.append(results[i])
return docs_and_scores
[docs] 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. Defaults to 4.
fetch_k: Number of Documents to fetch before filtering 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.
Returns:
List of Documents selected by maximal marginal relevance.
"""
docs_and_scores = self.max_marginal_relevance_search_with_score_by_vector(
embedding,
k=k,
fetch_k=fetch_k,
lambda_mult=lambda_mult,
filter=filter,
**kwargs,
)
return [doc for doc, _ in docs_and_scores]
[docs] 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: Text to look up documents similar to.
k: Number of Documents to return. Defaults to 4.
fetch_k: Number of Documents to fetch before filtering (if needed) 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.
Returns:
List of Documents selected by maximal marginal relevance.
"""
embedding = self.embedding_function(query)
docs = self.max_marginal_relevance_search_by_vector(
embedding,
k=k,
fetch_k=fetch_k,
lambda_mult=lambda_mult,
filter=filter,
**kwargs,
)
return docs
[docs] @classmethod
def create(
cls,
index_uri: str,
index_type: str,
dimensions: int,
vector_type: np.dtype,
*,
metadatas: bool = True,
config: Optional[Mapping[str, Any]] = None,
) -> None:
tiledb_vs, tiledb = dependable_tiledb_import()
with tiledb.scope_ctx(ctx_or_config=config):
try:
tiledb.group_create(index_uri)
except tiledb.TileDBError as err:
raise err
group = tiledb.Group(index_uri, "w")
vector_index_uri = get_vector_index_uri(group.uri)
docs_uri = get_documents_array_uri(group.uri)
if index_type == "FLAT":
tiledb_vs.flat_index.create(
uri=vector_index_uri,
dimensions=dimensions,
vector_type=vector_type,
config=config,
)
elif index_type == "IVF_FLAT":
tiledb_vs.ivf_flat_index.create(
uri=vector_index_uri,
dimensions=dimensions,
vector_type=vector_type,
config=config,
)
group.add(vector_index_uri, name=VECTOR_INDEX_NAME)
# Create TileDB array to store Documents
# TODO add a Document store API to tiledb-vector-search to allow storing
# different types of objects and metadata in a more generic way.
dim = tiledb.Dim(
name="id",
domain=(0, MAX_UINT64 - 1),
dtype=np.dtype(np.uint64),
)
dom = tiledb.Domain(dim)
text_attr = tiledb.Attr(name="text", dtype=np.dtype("U1"), var=True)
attrs = [text_attr]
if metadatas:
metadata_attr = tiledb.Attr(name="metadata", dtype=np.uint8, var=True)
attrs.append(metadata_attr)
schema = tiledb.ArraySchema(
domain=dom,
sparse=True,
allows_duplicates=False,
attrs=attrs,
)
tiledb.Array.create(docs_uri, schema)
group.add(docs_uri, name=DOCUMENTS_ARRAY_NAME)
group.close()
@classmethod
def __from(
cls,
texts: List[str],
embeddings: List[List[float]],
embedding: Embeddings,
index_uri: str,
*,
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
metric: str = DEFAULT_METRIC,
index_type: str = "FLAT",
config: Optional[Mapping[str, Any]] = None,
index_timestamp: int = 0,
**kwargs: Any,
) -> TileDB:
if metric not in INDEX_METRICS:
raise ValueError(
(
f"Unsupported distance metric: {metric}. "
f"Expected one of {list(INDEX_METRICS)}"
)
)
tiledb_vs, tiledb = dependable_tiledb_import()
input_vectors = np.array(embeddings).astype(np.float32)
cls.create(
index_uri=index_uri,
index_type=index_type,
dimensions=input_vectors.shape[1],
vector_type=input_vectors.dtype,
metadatas=metadatas is not None,
config=config,
)
with tiledb.scope_ctx(ctx_or_config=config):
if not embeddings:
raise ValueError("embeddings must be provided to build a TileDB index")
vector_index_uri = get_vector_index_uri(index_uri)
docs_uri = get_documents_array_uri(index_uri)
if ids is None:
ids = [str(random.randint(0, MAX_UINT64 - 1)) for _ in texts]
external_ids = np.array(ids).astype(np.uint64)
tiledb_vs.ingestion.ingest(
index_type=index_type,
index_uri=vector_index_uri,
input_vectors=input_vectors,
external_ids=external_ids,
index_timestamp=index_timestamp if index_timestamp != 0 else None,
config=config,
**kwargs,
)
with tiledb.open(docs_uri, "w") as A:
if external_ids is None:
external_ids = np.zeros(len(texts), dtype=np.uint64)
for i in range(len(texts)):
external_ids[i] = i
data = {}
data["text"] = np.array(texts)
if metadatas is not None:
metadata_attr = np.empty([len(metadatas)], dtype=object)
i = 0
for metadata in metadatas:
metadata_attr[i] = np.frombuffer(
pickle.dumps(metadata), dtype=np.uint8
)
i += 1
data["metadata"] = metadata_attr
A[external_ids] = data
return cls(
embedding=embedding,
index_uri=index_uri,
metric=metric,
config=config,
**kwargs,
)
[docs] def delete(
self, ids: Optional[List[str]] = None, timestamp: int = 0, **kwargs: Any
) -> Optional[bool]:
"""Delete by vector ID or other criteria.
Args:
ids: List of ids to delete.
timestamp: Optional timestamp to delete with.
**kwargs: Other keyword arguments that subclasses might use.
Returns:
Optional[bool]: True if deletion is successful,
False otherwise, None if not implemented.
"""
external_ids = np.array(ids).astype(np.uint64)
self.vector_index.delete_batch(
external_ids=external_ids, timestamp=timestamp if timestamp != 0 else None
)
return True
[docs] def add_texts(
self,
texts: Iterable[str],
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
timestamp: int = 0,
**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 ids of each text object.
timestamp: Optional timestamp to write new texts with.
kwargs: vectorstore specific parameters
Returns:
List of ids from adding the texts into the vectorstore.
"""
tiledb_vs, tiledb = dependable_tiledb_import()
embeddings = self.embedding.embed_documents(list(texts))
if ids is None:
ids = [str(random.randint(0, MAX_UINT64 - 1)) for _ in texts]
external_ids = np.array(ids).astype(np.uint64)
vectors = np.empty((len(embeddings)), dtype="O")
for i in range(len(embeddings)):
vectors[i] = np.array(embeddings[i], dtype=np.float32)
self.vector_index.update_batch(
vectors=vectors,
external_ids=external_ids,
timestamp=timestamp if timestamp != 0 else None,
)
docs = {}
docs["text"] = np.array(texts)
if metadatas is not None:
metadata_attr = np.empty([len(metadatas)], dtype=object)
i = 0
for metadata in metadatas:
metadata_attr[i] = np.frombuffer(pickle.dumps(metadata), dtype=np.uint8)
i += 1
docs["metadata"] = metadata_attr
docs_array = tiledb.open(
self.docs_array_uri,
"w",
timestamp=timestamp if timestamp != 0 else None,
config=self.config,
)
docs_array[external_ids] = docs
docs_array.close()
return ids
[docs] @classmethod
def from_texts(
cls,
texts: List[str],
embedding: Embeddings,
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
metric: str = DEFAULT_METRIC,
index_uri: str = "/tmp/tiledb_array",
index_type: str = "FLAT",
config: Optional[Mapping[str, Any]] = None,
index_timestamp: int = 0,
**kwargs: Any,
) -> TileDB:
"""Construct a TileDB index from raw documents.
Args:
texts: List of documents to index.
embedding: Embedding function to use.
metadatas: List of metadata dictionaries to associate with documents.
ids: Optional ids of each text object.
metric: Metric to use for indexing. Defaults to "euclidean".
index_uri: The URI to write the TileDB arrays
index_type: Optional, Vector index type ("FLAT", IVF_FLAT")
config: Optional, TileDB config
index_timestamp: Optional, timestamp to write new texts with.
Example:
.. code-block:: python
from langchain_community import TileDB
from langchain_community.embeddings import OpenAIEmbeddings
embeddings = OpenAIEmbeddings()
index = TileDB.from_texts(texts, embeddings)
"""
embeddings = []
embeddings = embedding.embed_documents(texts)
return cls.__from(
texts=texts,
embeddings=embeddings,
embedding=embedding,
metadatas=metadatas,
ids=ids,
metric=metric,
index_uri=index_uri,
index_type=index_type,
config=config,
index_timestamp=index_timestamp,
**kwargs,
)
[docs] @classmethod
def from_embeddings(
cls,
text_embeddings: List[Tuple[str, List[float]]],
embedding: Embeddings,
index_uri: str,
*,
metadatas: Optional[List[dict]] = None,
ids: Optional[List[str]] = None,
metric: str = DEFAULT_METRIC,
index_type: str = "FLAT",
config: Optional[Mapping[str, Any]] = None,
index_timestamp: int = 0,
**kwargs: Any,
) -> TileDB:
"""Construct TileDB index from embeddings.
Args:
text_embeddings: List of tuples of (text, embedding)
embedding: Embedding function to use.
index_uri: The URI to write the TileDB arrays
metadatas: List of metadata dictionaries to associate with documents.
metric: Optional, Metric to use for indexing. Defaults to "euclidean".
index_type: Optional, Vector index type ("FLAT", IVF_FLAT")
config: Optional, TileDB config
index_timestamp: Optional, timestamp to write new texts with.
Example:
.. code-block:: python
from langchain_community import TileDB
from langchain_community.embeddings import OpenAIEmbeddings
embeddings = OpenAIEmbeddings()
text_embeddings = embeddings.embed_documents(texts)
text_embedding_pairs = list(zip(texts, text_embeddings))
db = TileDB.from_embeddings(text_embedding_pairs, embeddings)
"""
texts = [t[0] for t in text_embeddings]
embeddings = [t[1] for t in text_embeddings]
return cls.__from(
texts=texts,
embeddings=embeddings,
embedding=embedding,
metadatas=metadatas,
ids=ids,
metric=metric,
index_uri=index_uri,
index_type=index_type,
config=config,
index_timestamp=index_timestamp,
**kwargs,
)
[docs] @classmethod
def load(
cls,
index_uri: str,
embedding: Embeddings,
*,
metric: str = DEFAULT_METRIC,
config: Optional[Mapping[str, Any]] = None,
timestamp: Any = None,
**kwargs: Any,
) -> TileDB:
"""Load a TileDB index from a URI.
Args:
index_uri: The URI of the TileDB vector index.
embedding: Embeddings to use when generating queries.
metric: Optional, Metric to use for indexing. Defaults to "euclidean".
config: Optional, TileDB config
timestamp: Optional, timestamp to use for opening the arrays.
"""
return cls(
embedding=embedding,
index_uri=index_uri,
metric=metric,
config=config,
timestamp=timestamp,
**kwargs,
)
[docs] def consolidate_updates(self, **kwargs: Any) -> None:
self.vector_index = self.vector_index.consolidate_updates(**kwargs)