from __future__ import annotations
import json
import logging
from hashlib import sha1
from threading import Thread
from typing import Any, Dict, Iterable, List, Optional, Tuple, Union
from langchain_core.documents import Document
from langchain_core.embeddings import Embeddings
from langchain_core.vectorstores import VectorStore
from pydantic_settings import BaseSettings, SettingsConfigDict
logger = logging.getLogger()
[docs]
def has_mul_sub_str(s: str, *args: Any) -> bool:
"""
Check if a string contains multiple substrings.
Args:
s: string to check.
*args: substrings to check.
Returns:
True if all substrings are in the string, False otherwise.
"""
for a in args:
if a not in s:
return False
return True
[docs]
class ClickhouseSettings(BaseSettings):
"""`ClickHouse` client configuration.
Attribute:
host (str) : An URL to connect to MyScale backend.
Defaults to 'localhost'.
port (int) : URL port to connect with HTTP. Defaults to 8443.
username (str) : Username to login. Defaults to None.
password (str) : Password to login. Defaults to None.
secure (bool) : Connect to server over secure connection. Defaults to False.
index_type (str): index type string.
index_param (list): index build parameter.
index_query_params(dict): index query parameters.
database (str) : Database name to find the table. Defaults to 'default'.
table (str) : Table name to operate on.
Defaults to 'vector_table'.
metric (str) : Metric to compute distance,
supported are ('angular', 'euclidean', 'manhattan', 'hamming',
'dot'). Defaults to 'angular'.
https://github.com/spotify/annoy/blob/main/src/annoymodule.cc#L149-L169
column_map (Dict) : Column type map to project column name onto langchain
semantics. Must have keys: `text`, `id`, `vector`,
must be same size to number of columns. For example:
.. code-block:: python
{
'id': 'text_id',
'uuid': 'global_unique_id'
'embedding': 'text_embedding',
'document': 'text_plain',
'metadata': 'metadata_dictionary_in_json',
}
Defaults to identity map.
"""
host: str = "localhost"
port: int = 8123
username: Optional[str] = None
password: Optional[str] = None
secure: bool = False
index_type: Optional[str] = "annoy"
# Annoy supports L2Distance and cosineDistance.
index_param: Optional[Union[List, Dict]] = ["'L2Distance'", 100]
index_query_params: Dict[str, str] = {}
column_map: Dict[str, str] = {
"id": "id",
"uuid": "uuid",
"document": "document",
"embedding": "embedding",
"metadata": "metadata",
}
database: str = "default"
table: str = "langchain"
metric: str = "angular"
def __getitem__(self, item: str) -> Any:
return getattr(self, item)
model_config = SettingsConfigDict(
env_file=".env",
env_file_encoding="utf-8",
env_prefix="clickhouse_",
extra="ignore",
)
[docs]
class Clickhouse(VectorStore):
"""ClickHouse vector store integration.
Setup:
Install ``langchain_community`` and ``clickhouse-connect``:
.. code-block:: bash
pip install -qU langchain_community clickhouse-connect
Key init args — indexing params:
embedding: Embeddings
Embedding function to use.
Key init args — client params:
config: Optional[ClickhouseSettings]
ClickHouse client configuration.
Instantiate:
.. code-block:: python
from langchain_community.vectorstores import Clickhouse, ClickhouseSettings
from langchain_openai import OpenAIEmbeddings
settings = ClickhouseSettings(table="clickhouse_example")
vector_store = Clickhouse(embedding=OpenAIEmbeddings(), config=settings)
Add Documents:
.. code-block:: python
from langchain_core.documents import Document
document_1 = Document(page_content="foo", metadata={"baz": "bar"})
document_2 = Document(page_content="thud", metadata={"bar": "baz"})
document_3 = Document(page_content="i will be deleted :(")
documents = [document_1, document_2, document_3]
ids = ["1", "2", "3"]
vector_store.add_documents(documents=documents, ids=ids)
Delete Documents:
.. code-block:: python
vector_store.delete(ids=["3"])
# TODO: Fill out example output.
Search:
.. code-block:: python
results = vector_store.similarity_search(query="thud",k=1)
for doc in results:
print(f"* {doc.page_content} [{doc.metadata}]")
.. code-block:: python
# TODO: Example output
# TODO: Fill out with relevant variables and example output.
Search with filter:
.. code-block:: python
# TODO: Edit filter if needed
results = vector_store.similarity_search(query="thud",k=1,filter="metadata.baz='bar'")
for doc in results:
print(f"* {doc.page_content} [{doc.metadata}]")
.. code-block:: python
# TODO: Example output
# TODO: Fill out with example output.
Search with score:
.. code-block:: python
results = vector_store.similarity_search_with_score(query="qux",k=1)
for doc, score in results:
print(f"* [SIM={score:3f}] {doc.page_content} [{doc.metadata}]")
.. code-block:: python
# TODO: Example output
# TODO: Fill out with example output.
Async:
.. code-block:: python
# add documents
# await vector_store.aadd_documents(documents=documents, ids=ids)
# delete documents
# await vector_store.adelete(ids=["3"])
# search
# results = vector_store.asimilarity_search(query="thud",k=1)
# search with score
results = await vector_store.asimilarity_search_with_score(query="qux",k=1)
for doc,score in results:
print(f"* [SIM={score:3f}] {doc.page_content} [{doc.metadata}]")
.. code-block:: python
# TODO: Example output
# TODO: Fill out with example output.
Use as Retriever:
.. code-block:: python
retriever = vector_store.as_retriever(
search_type="mmr",
search_kwargs={"k": 1, "fetch_k": 2, "lambda_mult": 0.5},
)
retriever.invoke("thud")
.. code-block:: python
# TODO: Example output
""" # noqa: E501
[docs]
def __init__(
self,
embedding: Embeddings,
config: Optional[ClickhouseSettings] = None,
**kwargs: Any,
) -> None:
"""ClickHouse Wrapper to LangChain
Args:
embedding_function (Embeddings): embedding function to use
config (ClickHouseSettings): Configuration to ClickHouse Client
kwargs (any): Other keyword arguments will pass into
[clickhouse-connect](https://docs.clickhouse.com/)
"""
try:
from clickhouse_connect import get_client
except ImportError:
raise ImportError(
"Could not import clickhouse connect python package. "
"Please install it with `pip install clickhouse-connect`."
)
try:
from tqdm import tqdm
self.pgbar = tqdm
except ImportError:
# Just in case if tqdm is not installed
self.pgbar = lambda x, **kwargs: x
super().__init__()
if config is not None:
self.config = config
else:
self.config = ClickhouseSettings()
assert self.config
assert self.config.host and self.config.port
assert (
self.config.column_map
and self.config.database
and self.config.table
and self.config.metric
)
for k in ["id", "embedding", "document", "metadata", "uuid"]:
assert k in self.config.column_map
assert self.config.metric in [
"angular",
"euclidean",
"manhattan",
"hamming",
"dot",
]
# initialize the schema
dim = len(embedding.embed_query("test"))
index_params = (
(
",".join([f"'{k}={v}'" for k, v in self.config.index_param.items()])
if self.config.index_param
else ""
)
if isinstance(self.config.index_param, Dict)
else (
",".join([str(p) for p in self.config.index_param])
if isinstance(self.config.index_param, List)
else self.config.index_param
)
)
self.schema = self._schema(dim, index_params)
self.dim = dim
self.BS = "\\"
self.must_escape = ("\\", "'")
self.embedding_function = embedding
self.dist_order = "ASC" # Only support ConsingDistance and L2Distance
# Create a connection to clickhouse
self.client = get_client(
host=self.config.host,
port=self.config.port,
username=self.config.username,
password=self.config.password,
secure=self.config.secure,
**kwargs,
)
# Enable JSON type
try:
self.client.command("SET allow_experimental_json_type=1")
except Exception as _:
logger.debug(
f"Clickhouse version={self.client.server_version} - "
"There is no allow_experimental_json_type parameter."
)
self.client.command("SET allow_experimental_object_type=1")
if self.config.index_type:
# Enable index
self.client.command(
f"SET allow_experimental_{self.config.index_type}_index=1"
)
self.client.command(self.schema)
def _schema(self, dim: int, index_params: Optional[str] = "") -> str:
"""Create table schema
:param dim: dimension of embeddings
:param index_params: parameters used for index
This function returns a `CREATE TABLE` statement based on the value of
`self.config.index_type`.
If an index type is specified that index will be created, otherwise
no index will be created.
In the case of there being no index, a linear scan will be performed
when the embedding field is queried.
"""
if self.config.index_type:
return f"""\
CREATE TABLE IF NOT EXISTS {self.config.database}.{self.config.table}(
{self.config.column_map['id']} Nullable(String),
{self.config.column_map['document']} Nullable(String),
{self.config.column_map['embedding']} Array(Float32),
{self.config.column_map['metadata']} JSON,
{self.config.column_map['uuid']} UUID DEFAULT generateUUIDv4(),
CONSTRAINT cons_vec_len CHECK length(
{self.config.column_map['embedding']}) = {dim},
INDEX vec_idx {self.config.column_map['embedding']} TYPE \
{self.config.index_type}({index_params}) GRANULARITY 1000
) ENGINE = MergeTree ORDER BY uuid SETTINGS index_granularity = 8192\
"""
else:
return f"""\
CREATE TABLE IF NOT EXISTS {self.config.database}.{self.config.table}(
{self.config.column_map['id']} Nullable(String),
{self.config.column_map['document']} Nullable(String),
{self.config.column_map['embedding']} Array(Float32),
{self.config.column_map['metadata']} JSON,
{self.config.column_map['uuid']} UUID DEFAULT generateUUIDv4(),
CONSTRAINT cons_vec_len CHECK length({
self.config.column_map['embedding']}) = {dim}
) ENGINE = MergeTree ORDER BY uuid
"""
@property
def embeddings(self) -> Embeddings:
"""Provides access to the embedding mechanism used by the Clickhouse instance.
This property allows direct access to the embedding function or model being
used by the Clickhouse instance to convert text documents into embedding vectors
for vector similarity search.
Returns:
The `Embeddings` instance associated with this Clickhouse instance.
"""
return self.embedding_function
[docs]
def escape_str(self, value: str) -> str:
"""Escape special characters in a string for Clickhouse SQL queries.
This method is used internally to prepare strings for safe insertion
into SQL queries by escaping special characters that might otherwise
interfere with the query syntax.
Args:
value: The string to be escaped.
Returns:
The escaped string, safe for insertion into SQL queries.
"""
return "".join(f"{self.BS}{c}" if c in self.must_escape else c for c in value)
def _build_insert_sql(self, transac: Iterable, column_names: Iterable[str]) -> str:
"""Construct an SQL query for inserting data into the Clickhouse database.
This method formats and constructs an SQL `INSERT` query string using the
provided transaction data and column names. It is utilized internally during
the process of batch insertion of documents and their embeddings into the
database.
Args:
transac: iterable of tuples, representing a row of data to be inserted.
column_names: iterable of strings representing the names of the columns
into which data will be inserted.
Returns:
A string containing the constructed SQL `INSERT` query.
"""
ks = ",".join(column_names)
_data = []
for n in transac:
n = ",".join([f"'{self.escape_str(str(_n))}'" for _n in n])
_data.append(f"({n})")
i_str = f"""
INSERT INTO TABLE
{self.config.database}.{self.config.table}({ks})
VALUES
{','.join(_data)}
"""
return i_str
def _insert(self, transac: Iterable, column_names: Iterable[str]) -> None:
"""Execute an SQL query to insert data into the Clickhouse database.
This method performs the actual insertion of data into the database by
executing the SQL query constructed by `_build_insert_sql`. It's a critical
step in adding new documents and their associated data into the vector store.
Args:
transac:iterable of tuples, representing a row of data to be inserted.
column_names: An iterable of strings representing the names of the columns
into which data will be inserted.
"""
_insert_query = self._build_insert_sql(transac, column_names)
self.client.command(_insert_query)
[docs]
def add_texts(
self,
texts: Iterable[str],
metadatas: Optional[List[dict]] = None,
batch_size: int = 32,
ids: Optional[Iterable[str]] = None,
**kwargs: Any,
) -> List[str]:
"""Insert more texts through the embeddings and add to the VectorStore.
Args:
texts: Iterable of strings to add to the VectorStore.
ids: Optional list of ids to associate with the texts.
batch_size: Batch size of insertion
metadata: Optional column data to be inserted
Returns:
List of ids from adding the texts into the VectorStore.
"""
# Embed and create the documents
ids = ids or [sha1(t.encode("utf-8")).hexdigest() for t in texts]
colmap_ = self.config.column_map
transac = []
column_names = {
colmap_["id"]: ids,
colmap_["document"]: texts,
colmap_["embedding"]: self.embedding_function.embed_documents(list(texts)),
}
metadatas = metadatas or [{} for _ in texts]
column_names[colmap_["metadata"]] = map(json.dumps, metadatas)
assert len(set(colmap_) - set(column_names)) >= 0
keys, values = zip(*column_names.items())
try:
t = None
for v in self.pgbar(
zip(*values), desc="Inserting data...", total=len(metadatas)
):
assert (
len(v[keys.index(self.config.column_map["embedding"])]) == self.dim
)
transac.append(v)
if len(transac) == batch_size:
if t:
t.join()
t = Thread(target=self._insert, args=[transac, keys])
t.start()
transac = []
if len(transac) > 0:
if t:
t.join()
self._insert(transac, keys)
return [i for i in ids]
except Exception as e:
logger.error(f"\033[91m\033[1m{type(e)}\033[0m \033[95m{str(e)}\033[0m")
return []
[docs]
@classmethod
def from_texts(
cls,
texts: List[str],
embedding: Embeddings,
metadatas: Optional[List[Dict[Any, Any]]] = None,
config: Optional[ClickhouseSettings] = None,
text_ids: Optional[Iterable[str]] = None,
batch_size: int = 32,
**kwargs: Any,
) -> Clickhouse:
"""Create ClickHouse wrapper with existing texts
Args:
embedding_function (Embeddings): Function to extract text embedding
texts (Iterable[str]): List or tuple of strings to be added
config (ClickHouseSettings, Optional): ClickHouse configuration
text_ids (Optional[Iterable], optional): IDs for the texts.
Defaults to None.
batch_size (int, optional): Batchsize when transmitting data to ClickHouse.
Defaults to 32.
metadata (List[dict], optional): metadata to texts. Defaults to None.
Other keyword arguments will pass into
[clickhouse-connect](https://clickhouse.com/docs/en/integrations/python#clickhouse-connect-driver-api)
Returns:
ClickHouse Index
"""
ctx = cls(embedding, config, **kwargs)
ctx.add_texts(texts, ids=text_ids, batch_size=batch_size, metadatas=metadatas)
return ctx
def __repr__(self) -> str:
"""Text representation for ClickHouse Vector Store, prints backends, username
and schemas. Easy to use with `str(ClickHouse())`
Returns:
repr: string to show connection info and data schema
"""
_repr = f"\033[92m\033[1m{self.config.database}.{self.config.table} @ "
_repr += f"{self.config.host}:{self.config.port}\033[0m\n\n"
_repr += f"\033[1musername: {self.config.username}\033[0m\n\nTable Schema:\n"
_repr += "-" * 51 + "\n"
for r in self.client.query(
f"DESC {self.config.database}.{self.config.table}"
).named_results():
_repr += (
f"|\033[94m{r['name']:24s}\033[0m|\033[96m{r['type']:24s}\033[0m|\n"
)
_repr += "-" * 51 + "\n"
return _repr
def _build_query_sql(
self, q_emb: List[float], topk: int, where_str: Optional[str] = None
) -> str:
"""Construct an SQL query for performing a similarity search.
This internal method generates an SQL query for finding the top-k most similar
vectors in the database to a given query vector.It allows for optional filtering
conditions to be applied via a WHERE clause.
Args:
q_emb: The query vector as a list of floats.
topk: The number of top similar items to retrieve.
where_str: opt str representing additional WHERE conditions for the query
Defaults to None.
Returns:
A string containing the SQL query for the similarity search.
"""
q_emb_str = ",".join(map(str, q_emb))
if where_str:
where_str = f"PREWHERE {where_str}"
else:
where_str = ""
settings_strs = []
if self.config.index_query_params:
for k in self.config.index_query_params:
settings_strs.append(f"SETTING {k}={self.config.index_query_params[k]}")
q_str = f"""
SELECT {self.config.column_map['document']},
{self.config.column_map['metadata']}, dist
FROM {self.config.database}.{self.config.table}
{where_str}
ORDER BY L2Distance({self.config.column_map['embedding']}, [{q_emb_str}])
AS dist {self.dist_order}
LIMIT {topk} {' '.join(settings_strs)}
"""
return q_str
[docs]
def similarity_search(
self, query: str, k: int = 4, where_str: Optional[str] = None, **kwargs: Any
) -> List[Document]:
"""Perform a similarity search with ClickHouse
Args:
query (str): query string
k (int, optional): Top K neighbors to retrieve. Defaults to 4.
where_str (Optional[str], optional): where condition string.
Defaults to None.
NOTE: Please do not let end-user to fill this and always be aware
of SQL injection. When dealing with metadatas, remember to
use `{self.metadata_column}.attribute` instead of `attribute`
alone. The default name for it is `metadata`.
Returns:
List[Document]: List of Documents
"""
return self.similarity_search_by_vector(
self.embedding_function.embed_query(query), k, where_str, **kwargs
)
[docs]
def similarity_search_by_vector(
self,
embedding: List[float],
k: int = 4,
where_str: Optional[str] = None,
**kwargs: Any,
) -> List[Document]:
"""Perform a similarity search with ClickHouse by vectors
Args:
query (str): query string
k (int, optional): Top K neighbors to retrieve. Defaults to 4.
where_str (Optional[str], optional): where condition string.
Defaults to None.
NOTE: Please do not let end-user to fill this and always be aware
of SQL injection. When dealing with metadatas, remember to
use `{self.metadata_column}.attribute` instead of `attribute`
alone. The default name for it is `metadata`.
Returns:
List[Document]: List of documents
"""
q_str = self._build_query_sql(embedding, k, where_str)
try:
return [
Document(
page_content=r[self.config.column_map["document"]],
metadata=r[self.config.column_map["metadata"]],
)
for r in self.client.query(q_str).named_results()
]
except Exception as e:
logger.error(f"\033[91m\033[1m{type(e)}\033[0m \033[95m{str(e)}\033[0m")
return []
[docs]
def similarity_search_with_relevance_scores(
self, query: str, k: int = 4, where_str: Optional[str] = None, **kwargs: Any
) -> List[Tuple[Document, float]]:
"""Perform a similarity search with ClickHouse
Args:
query (str): query string
k (int, optional): Top K neighbors to retrieve. Defaults to 4.
where_str (Optional[str], optional): where condition string.
Defaults to None.
NOTE: Please do not let end-user to fill this and always be aware
of SQL injection. When dealing with metadatas, remember to
use `{self.metadata_column}.attribute` instead of `attribute`
alone. The default name for it is `metadata`.
Returns:
List[Document]: List of (Document, similarity)
"""
q_str = self._build_query_sql(
self.embedding_function.embed_query(query), k, where_str
)
try:
return [
(
Document(
page_content=r[self.config.column_map["document"]],
metadata=r[self.config.column_map["metadata"]],
),
r["dist"],
)
for r in self.client.query(q_str).named_results()
]
except Exception as e:
logger.error(f"\033[91m\033[1m{type(e)}\033[0m \033[95m{str(e)}\033[0m")
return []
[docs]
def drop(self) -> None:
"""
Helper function: Drop data
"""
self.client.command(
f"DROP TABLE IF EXISTS {self.config.database}.{self.config.table}"
)
@property
def metadata_column(self) -> str:
return self.config.column_map["metadata"]
