from __future__ import annotations
import logging
import uuid
from typing import Any, List, 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
logger = logging.getLogger(__name__)
[docs]class VikingDBConfig(object):
"""vikingdb connection config
See the following documentation for details:
https://www.volcengine.com/docs/6459/1167770
Attribute:
host(str):The access address of the vector database server
that the client needs to connect to.
region(str):"cn-shanghai" or "cn-beijing"
ak(str):Access Key ID, security credentials for accessing
Volcano Engine services.
sk(str):Secret Access Key, security credentials for accessing
Volcano Engine services.
scheme(str):http or https, defaulting to http.
"""
[docs] def __init__(self, host="host", region="region", ak="ak", sk="sk", scheme="http"): # type: ignore[no-untyped-def]
self.host = host
self.region = region
self.ak = ak
self.sk = sk
self.scheme = scheme
[docs]class VikingDB(VectorStore):
"""vikingdb as a vector store
In order to use this you need to have a database instance.
See the following documentation for details:
https://www.volcengine.com/docs/6459/1167774
"""
[docs] def __init__(
self,
embedding_function: Embeddings,
collection_name: str = "LangChainCollection",
connection_args: Optional[VikingDBConfig] = None,
index_params: Optional[dict] = None,
drop_old: Optional[bool] = False,
**kwargs: Any,
):
try:
from volcengine.viking_db import Collection, VikingDBService
except ImportError:
raise ImportError(
"Could not import volcengine python package. "
"Please install it with `pip install --upgrade volcengine`."
)
self.embedding_func = embedding_function
self.collection_name = collection_name
self.index_name = "LangChainIndex"
self.connection_args = connection_args
self.index_params = index_params
self.drop_old = drop_old
self.service = VikingDBService(
connection_args.host, # type: ignore[union-attr]
connection_args.region, # type: ignore[union-attr]
connection_args.ak, # type: ignore[union-attr]
connection_args.sk, # type: ignore[union-attr]
connection_args.scheme, # type: ignore[union-attr]
)
try:
col = self.service.get_collection(collection_name)
except Exception:
col = None
self.collection = col
self.index = None
if self.collection is not None:
self.index = self.service.get_index(self.collection_name, self.index_name)
if drop_old and isinstance(self.collection, Collection):
indexes = self.service.list_indexes(collection_name)
for index in indexes:
self.service.drop_index(collection_name, index.index_name)
self.service.drop_collection(collection_name)
self.collection = None
self.index = None
@property
def embeddings(self) -> Embeddings:
return self.embedding_func
def _create_collection(
self, embeddings: List, metadatas: Optional[List[dict]] = None
) -> None:
try:
from volcengine.viking_db import Field, FieldType
except ImportError:
raise ImportError(
"Could not import volcengine python package. "
"Please install it with `pip install --upgrade volcengine`."
)
dim = len(embeddings[0])
fields = []
if metadatas:
for key, value in metadatas[0].items():
# print(key, value)
if isinstance(value, str):
fields.append(Field(key, FieldType.String))
elif isinstance(value, int):
fields.append(Field(key, FieldType.Int64))
elif isinstance(value, bool):
fields.append(Field(key, FieldType.Bool))
elif isinstance(value, list) and all(
isinstance(item, str) for item in value
):
fields.append(Field(key, FieldType.List_String))
elif isinstance(value, list) and all(
isinstance(item, int) for item in value
):
fields.append(Field(key, FieldType.List_Int64))
elif isinstance(value, bytes):
fields.append(Field(key, FieldType.Text))
else:
raise ValueError(
"metadatas value is invalid"
"please change the type of metadatas."
)
# fields.append(Field("text", FieldType.String))
fields.append(Field("text", FieldType.Text))
fields.append(Field("primary_key", FieldType.String, is_primary_key=True))
fields.append(Field("vector", FieldType.Vector, dim=dim))
self.collection = self.service.create_collection(self.collection_name, fields)
def _create_index(self) -> None:
try:
from volcengine.viking_db import VectorIndexParams
except ImportError:
raise ImportError(
"Could not import volcengine python package. "
"Please install it with `pip install --upgrade volcengine`."
)
cpu_quota = 2
vector_index = VectorIndexParams()
partition_by = ""
scalar_index = None
if self.index_params is not None:
if self.index_params.get("cpu_quota") is not None:
cpu_quota = self.index_params["cpu_quota"]
if self.index_params.get("vector_index") is not None:
vector_index = self.index_params["vector_index"]
if self.index_params.get("partition_by") is not None:
partition_by = self.index_params["partition_by"]
if self.index_params.get("scalar_index") is not None:
scalar_index = self.index_params["scalar_index"]
self.index = self.service.create_index(
self.collection_name,
self.index_name,
vector_index=vector_index,
cpu_quota=cpu_quota,
partition_by=partition_by,
scalar_index=scalar_index,
)
[docs] def add_texts( # type: ignore[override]
self,
texts: List[str],
metadatas: Optional[List[dict]] = None,
batch_size: int = 1000,
**kwargs: Any,
) -> List[str]:
"""Insert text data into VikingDB."""
try:
from volcengine.viking_db import Data
except ImportError:
raise ImportError(
"Could not import volcengine python package. "
"Please install it with `pip install --upgrade volcengine`."
)
texts = list(texts)
try:
embeddings = self.embedding_func.embed_documents(texts)
except NotImplementedError:
embeddings = [self.embedding_func.embed_query(x) for x in texts]
if len(embeddings) == 0:
logger.debug("Nothing to insert, skipping.")
return []
if self.collection is None:
self._create_collection(embeddings, metadatas)
self._create_index()
# insert data
data = []
pks: List[str] = []
for index in range(len(embeddings)):
primary_key = str(uuid.uuid4())
pks.append(primary_key)
field = {
"text": texts[index],
"primary_key": primary_key,
"vector": embeddings[index],
}
if metadatas is not None and index < len(metadatas):
names = list(metadatas[index].keys())
for name in names:
field[name] = metadatas[index].get(name) # type: ignore[assignment]
data.append(Data(field))
total_count = len(data)
for i in range(0, total_count, batch_size):
end = min(i + batch_size, total_count)
insert_data = data[i:end]
# print(insert_data)
self.collection.upsert_data(insert_data) # type: ignore[union-attr]
return pks
[docs] def similarity_search( # type: ignore[override]
self,
query: str,
params: Optional[dict] = None,
**kwargs: Any,
) -> List[Document]:
"""Perform a similarity search against the query string."""
res = self.similarity_search_with_score(query=query, params=params, **kwargs)
return [doc for doc, _ in res]
[docs] def similarity_search_with_score(
self,
query: str,
params: Optional[dict] = None,
**kwargs: Any,
) -> List[Tuple[Document, float]]:
"""Perform a search on a query string and return results with score."""
embedding = self.embedding_func.embed_query(query)
res = self.similarity_search_with_score_by_vector(
embedding=embedding, params=params, **kwargs
)
return res
[docs] def similarity_search_by_vector( # type: ignore[override]
self,
embedding: List[float],
params: Optional[dict] = None,
**kwargs: Any,
) -> List[Document]:
"""Perform a similarity search against the query string."""
res = self.similarity_search_with_score_by_vector(
embedding=embedding, params=params, **kwargs
)
return [doc for doc, _ in res]
[docs] def similarity_search_with_score_by_vector(
self,
embedding: List[float],
params: Optional[dict] = None,
**kwargs: Any,
) -> List[Tuple[Document, float]]:
"""Perform a search on a query string and return results with score."""
if self.collection is None:
logger.debug("No existing collection to search.")
return []
filter = None
limit = 10
output_fields = None
partition = "default"
if params is not None:
if params.get("filter") is not None:
filter = params["filter"]
if params.get("limit") is not None:
limit = params["limit"]
if params.get("output_fields") is not None:
output_fields = params["output_fields"]
if params.get("partition") is not None:
partition = params["partition"]
res = self.index.search_by_vector( # type: ignore[union-attr]
embedding,
filter=filter,
limit=limit,
output_fields=output_fields,
partition=partition,
)
ret = []
for item in res:
if "primary_key" in item.fields:
item.fields.pop("primary_key")
if "vector" in item.fields:
item.fields.pop("vector")
page_content = ""
if "text" in item.fields:
page_content = item.fields.pop("text")
doc = Document(page_content=page_content, metadata=item.fields)
pair = (doc, item.score)
ret.append(pair)
return ret
[docs] def max_marginal_relevance_search( # type: ignore[override]
self,
query: str,
k: int = 4,
lambda_mult: float = 0.5,
params: Optional[dict] = None,
**kwargs: Any,
) -> List[Document]:
"""Perform a search and return results that are reordered by MMR."""
embedding = self.embedding_func.embed_query(query)
return self.max_marginal_relevance_search_by_vector(
embedding=embedding,
k=k,
lambda_mult=lambda_mult,
params=params,
**kwargs,
)
[docs] def max_marginal_relevance_search_by_vector( # type: ignore[override]
self,
embedding: List[float],
k: int = 4,
lambda_mult: float = 0.5,
params: Optional[dict] = None,
**kwargs: Any,
) -> List[Document]:
"""Perform a search and return results that are reordered by MMR."""
if self.collection is None:
logger.debug("No existing collection to search.")
return []
filter = None
limit = 10
output_fields = None
partition = "default"
if params is not None:
if params.get("filter") is not None:
filter = params["filter"]
if params.get("limit") is not None:
limit = params["limit"]
if params.get("output_fields") is not None:
output_fields = params["output_fields"]
if params.get("partition") is not None:
partition = params["partition"]
res = self.index.search_by_vector( # type: ignore[union-attr]
embedding,
filter=filter,
limit=limit,
output_fields=output_fields,
partition=partition,
)
documents = []
ordered_result_embeddings = []
for item in res:
if (
"vector" not in item.fields
or "primary_key" not in item.fields
or "text" not in item.fields
):
continue
ordered_result_embeddings.append(item.fields.pop("vector"))
item.fields.pop("primary_key")
page_content = item.fields.pop("text")
doc = Document(page_content=page_content, metadata=item.fields)
documents.append(doc)
new_ordering = maximal_marginal_relevance(
np.array(embedding), ordered_result_embeddings, k=k, lambda_mult=lambda_mult
)
# Reorder the values and return.
ret = []
for x in new_ordering:
# Function can return -1 index
if x == -1:
break
else:
ret.append(documents[x])
return ret
[docs] def delete(
self,
ids: Optional[List[str]] = None,
**kwargs: Any,
) -> None:
if self.collection is None:
logger.debug("No existing collection to search.")
self.collection.delete_data(ids) # type: ignore[union-attr]
[docs] @classmethod
def from_texts( # type: ignore[no-untyped-def, override]
cls,
texts: List[str],
embedding: Embeddings,
connection_args: Optional[VikingDBConfig] = None,
metadatas: Optional[List[dict]] = None,
collection_name: str = "LangChainCollection",
index_params: Optional[dict] = None,
drop_old: bool = False,
**kwargs: Any,
):
"""Create a collection, indexes it and insert data."""
if connection_args is None:
raise Exception("VikingDBConfig does not exists")
vector_db = cls(
embedding_function=embedding,
collection_name=collection_name,
connection_args=connection_args,
index_params=index_params,
drop_old=drop_old,
**kwargs,
)
vector_db.add_texts(texts=texts, metadatas=metadatas)
return vector_db
