Files
t6_mem0/embedchain/vectordb/weaviate.py
2024-01-23 14:24:29 +05:30

362 lines
14 KiB
Python

import copy
import os
from typing import Optional, Union
try:
import weaviate
except ImportError:
raise ImportError(
"Weaviate requires extra dependencies. Install with `pip install --upgrade 'embedchain[weaviate]'`"
) from None
from embedchain.config.vectordb.weaviate import WeaviateDBConfig
from embedchain.helpers.json_serializable import register_deserializable
from embedchain.vectordb.base import BaseVectorDB
@register_deserializable
class WeaviateDB(BaseVectorDB):
"""
Weaviate as vector database
"""
BATCH_SIZE = 100
def __init__(
self,
config: Optional[WeaviateDBConfig] = None,
):
"""Weaviate as vector database.
:param config: Weaviate database config, defaults to None
:type config: WeaviateDBConfig, optional
:raises ValueError: No config provided
"""
if config is None:
self.config = WeaviateDBConfig()
else:
if not isinstance(config, WeaviateDBConfig):
raise TypeError(
"config is not a `WeaviateDBConfig` instance. "
"Please make sure the type is right and that you are passing an instance."
)
self.config = config
self.client = weaviate.Client(
url=os.environ.get("WEAVIATE_ENDPOINT"),
auth_client_secret=weaviate.AuthApiKey(api_key=os.environ.get("WEAVIATE_API_KEY")),
**self.config.extra_params,
)
# Since weaviate uses graphQL, we need to keep track of metadata keys added in the vectordb.
# This is needed to filter data while querying.
self.metadata_keys = {"data_type", "doc_id", "url", "hash", "app_id"}
# Call parent init here because embedder is needed
super().__init__(config=self.config)
def _initialize(self):
"""
This method is needed because `embedder` attribute needs to be set externally before it can be initialized.
"""
if not self.embedder:
raise ValueError("Embedder not set. Please set an embedder with `set_embedder` before initialization.")
self.index_name = self._get_index_name()
if not self.client.schema.exists(self.index_name):
# id is a reserved field in Weaviate, hence we had to change the name of the id field to identifier
# The none vectorizer is crucial as we have our own custom embedding function
"""
TODO: wait for weaviate to add indexing on `object[]` data-type so that we can add filter while querying.
Once that is done, change `dataType` of "metadata" field to `object[]` and update the query below.
"""
class_obj = {
"classes": [
{
"class": self.index_name,
"vectorizer": "none",
"properties": [
{
"name": "identifier",
"dataType": ["text"],
},
{
"name": "text",
"dataType": ["text"],
},
{
"name": "metadata",
"dataType": [self.index_name + "_metadata"],
},
],
},
{
"class": self.index_name + "_metadata",
"vectorizer": "none",
"properties": [
{
"name": "data_type",
"dataType": ["text"],
},
{
"name": "doc_id",
"dataType": ["text"],
},
{
"name": "url",
"dataType": ["text"],
},
{
"name": "hash",
"dataType": ["text"],
},
{
"name": "app_id",
"dataType": ["text"],
},
],
},
]
}
self.client.schema.create(class_obj)
def get(self, ids: Optional[list[str]] = None, where: Optional[dict[str, any]] = None, limit: Optional[int] = None):
"""
Get existing doc ids present in vector database
:param ids: _list of doc ids to check for existance
:type ids: list[str]
:param where: to filter data
:type where: dict[str, any]
:return: ids
:rtype: Set[str]
"""
weaviate_where_operands = []
if ids:
for doc_id in ids:
weaviate_where_operands.append({"path": ["identifier"], "operator": "Equal", "valueText": doc_id})
keys = set(where.keys() if where is not None else set())
if len(keys) > 0:
for key in keys:
weaviate_where_operands.append(
{
"path": ["metadata", self.index_name + "_metadata", key],
"operator": "Equal",
"valueText": where.get(key),
}
)
if len(weaviate_where_operands) == 1:
weaviate_where_clause = weaviate_where_operands[0]
else:
weaviate_where_clause = {"operator": "And", "operands": weaviate_where_operands}
existing_ids = []
metadatas = []
cursor = None
offset = 0
has_iterated_once = False
query_metadata_keys = self.metadata_keys.union(keys)
while cursor is not None or not has_iterated_once:
has_iterated_once = True
results = self._query_with_offset(
self.client.query.get(
self.index_name,
[
"identifier",
weaviate.LinkTo("metadata", self.index_name + "_metadata", list(query_metadata_keys)),
],
)
.with_where(weaviate_where_clause)
.with_additional(["id"])
.with_limit(limit or self.BATCH_SIZE),
offset,
)
fetched_results = results["data"]["Get"].get(self.index_name, [])
if not fetched_results:
break
for result in fetched_results:
existing_ids.append(result["identifier"])
metadatas.append(result["metadata"][0])
cursor = result["_additional"]["id"]
offset += 1
if limit is not None and len(existing_ids) >= limit:
break
return {"ids": existing_ids, "metadatas": metadatas}
def add(self, documents: list[str], metadatas: list[object], ids: list[str], **kwargs: Optional[dict[str, any]]):
"""add data in vector database
:param documents: list of texts to add
:type documents: list[str]
:param metadatas: list of metadata associated with docs
:type metadatas: list[object]
:param ids: ids of docs
:type ids: list[str]
"""
embeddings = self.embedder.embedding_fn(documents)
self.client.batch.configure(batch_size=self.BATCH_SIZE, timeout_retries=3) # Configure batch
with self.client.batch as batch: # Initialize a batch process
for id, text, metadata, embedding in zip(ids, documents, metadatas, embeddings):
doc = {"identifier": id, "text": text}
updated_metadata = {"text": text}
if metadata is not None:
updated_metadata.update(**metadata)
obj_uuid = batch.add_data_object(
data_object=copy.deepcopy(doc), class_name=self.index_name, vector=embedding
)
metadata_uuid = batch.add_data_object(
data_object=copy.deepcopy(updated_metadata),
class_name=self.index_name + "_metadata",
vector=embedding,
)
batch.add_reference(
obj_uuid, self.index_name, "metadata", metadata_uuid, self.index_name + "_metadata", **kwargs
)
def query(
self, input_query: list[str], n_results: int, where: dict[str, any], citations: bool = False
) -> Union[list[tuple[str, dict]], list[str]]:
"""
query contents from vector database based on vector similarity
:param input_query: list of query string
:type input_query: list[str]
:param n_results: no of similar documents to fetch from database
:type n_results: int
:param where: Optional. to filter data
:type where: dict[str, any]
:param citations: we use citations boolean param to return context along with the answer.
:type citations: bool, default is False.
:return: The content of the document that matched your query,
along with url of the source and doc_id (if citations flag is true)
:rtype: list[str], if citations=False, otherwise list[tuple[str, str, str]]
"""
query_vector = self.embedder.embedding_fn([input_query])[0]
keys = set(where.keys() if where is not None else set())
data_fields = ["text"]
query_metadata_keys = self.metadata_keys.union(keys)
if citations:
data_fields.append(weaviate.LinkTo("metadata", self.index_name + "_metadata", list(query_metadata_keys)))
if len(keys) > 0:
weaviate_where_operands = []
for key in keys:
weaviate_where_operands.append(
{
"path": ["metadata", self.index_name + "_metadata", key],
"operator": "Equal",
"valueText": where.get(key),
}
)
if len(weaviate_where_operands) == 1:
weaviate_where_clause = weaviate_where_operands[0]
else:
weaviate_where_clause = {"operator": "And", "operands": weaviate_where_operands}
results = (
self.client.query.get(self.index_name, data_fields)
.with_where(weaviate_where_clause)
.with_near_vector({"vector": query_vector})
.with_limit(n_results)
.with_additional(["distance"])
.do()
)
else:
results = (
self.client.query.get(self.index_name, data_fields)
.with_near_vector({"vector": query_vector})
.with_limit(n_results)
.with_additional(["distance"])
.do()
)
docs = results["data"]["Get"].get(self.index_name)
contexts = []
for doc in docs:
context = doc["text"]
if citations:
metadata = doc["metadata"][0]
score = doc["_additional"]["distance"]
metadata["score"] = score
contexts.append((context, metadata))
else:
contexts.append(context)
return contexts
def set_collection_name(self, name: str):
"""
Set the name of the collection. A collection is an isolated space for vectors.
:param name: Name of the collection.
:type name: str
"""
if not isinstance(name, str):
raise TypeError("Collection name must be a string")
self.config.collection_name = name
def count(self) -> int:
"""
Count number of documents/chunks embedded in the database.
:return: number of documents
:rtype: int
"""
data = self.client.query.aggregate(self.index_name).with_meta_count().do()
return data["data"]["Aggregate"].get(self.index_name)[0]["meta"]["count"]
def _get_or_create_db(self):
"""Called during initialization"""
return self.client
def reset(self):
"""
Resets the database. Deletes all embeddings irreversibly.
"""
# Delete all data from the database
self.client.batch.delete_objects(
self.index_name, where={"path": ["identifier"], "operator": "Like", "valueText": ".*"}
)
# Weaviate internally by default capitalizes the class name
def _get_index_name(self) -> str:
"""Get the Weaviate index for a collection
:return: Weaviate index
:rtype: str
"""
return f"{self.config.collection_name}_{self.embedder.vector_dimension}".capitalize().replace("-", "_")
@staticmethod
def _query_with_offset(query, offset):
if offset:
query.with_offset(offset)
results = query.do()
return results
def _generate_query(self, where: dict):
weaviate_where_operands = []
for key, value in where.items():
weaviate_where_operands.append(
{
"path": ["metadata", self.index_name + "_metadata", key],
"operator": "Equal",
"valueText": value,
}
)
if len(weaviate_where_operands) == 1:
weaviate_where_clause = weaviate_where_operands[0]
else:
weaviate_where_clause = {"operator": "And", "operands": weaviate_where_operands}
return weaviate_where_clause
def delete(self, where: dict):
"""Delete from database.
:param where: to filter data
:type where: dict[str, any]
"""
query = self._generate_query(where)
self.client.batch.delete_objects(self.index_name, where=query)