Files
LangBot/src/langbot/pkg/vector/vdbs/milvus.py
Junyan Qin (Chin) 86e951916e feat: add milvus and pgvector as vector db (#1840)
* feat: add milvus and pgvector as vector db

* chore: update config.yaml template delete comments
2025-12-04 22:34:49 +08:00

250 lines
8.5 KiB
Python

from __future__ import annotations
import asyncio
from typing import Any, Dict
from pymilvus import MilvusClient, DataType
from langbot.pkg.vector.vdb import VectorDatabase
from langbot.pkg.core import app
class MilvusVectorDatabase(VectorDatabase):
"""Milvus vector database implementation"""
def __init__(self, ap: app.Application, uri: str = "milvus.db", token: str = None):
"""Initialize Milvus vector database
Args:
ap: Application instance
uri: Milvus connection URI. For local file: "milvus.db"
For remote server: "http://localhost:19530"
token: Optional authentication token for remote connections
"""
self.ap = ap
self.uri = uri
self.token = token
self.client = None
self._collections = {}
self._initialize_client()
def _initialize_client(self):
"""Initialize Milvus client connection"""
try:
if self.token:
self.client = MilvusClient(uri=self.uri, token=self.token)
else:
self.client = MilvusClient(uri=self.uri)
self.ap.logger.info(f"Connected to Milvus at {self.uri}")
except Exception as e:
self.ap.logger.error(f"Failed to connect to Milvus: {e}")
raise
async def get_or_create_collection(self, collection: str):
"""Get or create a Milvus collection
Args:
collection: Collection name (corresponds to knowledge base UUID)
"""
if collection in self._collections:
return self._collections[collection]
# Check if collection exists
has_collection = await asyncio.to_thread(
self.client.has_collection, collection_name=collection
)
if not has_collection:
# Create collection with custom schema to support string IDs
from pymilvus import CollectionSchema, FieldSchema, DataType
fields = [
FieldSchema(name="id", dtype=DataType.VARCHAR, is_primary=True, max_length=255),
FieldSchema(name="vector", dtype=DataType.FLOAT_VECTOR, dim=1536),
FieldSchema(name="text", dtype=DataType.VARCHAR, max_length=65535),
FieldSchema(name="file_id", dtype=DataType.VARCHAR, max_length=255),
FieldSchema(name="chunk_uuid", dtype=DataType.VARCHAR, max_length=255),
]
schema = CollectionSchema(fields=fields, description="LangBot knowledge base vectors")
await asyncio.to_thread(
self.client.create_collection,
collection_name=collection,
schema=schema,
metric_type="COSINE",
)
# Create index for vector field (required for loading/searching)
index_params = {
"metric_type": "COSINE",
"index_type": "AUTOINDEX",
"params": {}
}
await asyncio.to_thread(
self.client.create_index,
collection_name=collection,
field_name="vector",
index_params=index_params
)
self.ap.logger.info(f"Created Milvus collection '{collection}' with index")
else:
self.ap.logger.info(f"Milvus collection '{collection}' already exists")
self._collections[collection] = collection
return collection
async def add_embeddings(
self,
collection: str,
ids: list[str],
embeddings_list: list[list[float]],
metadatas: list[dict[str, Any]],
) -> None:
"""Add vector embeddings to Milvus collection
Args:
collection: Collection name
ids: List of unique IDs for each vector
embeddings_list: List of embedding vectors
metadatas: List of metadata dictionaries for each vector
"""
await self.get_or_create_collection(collection)
# Prepare data in Milvus format
data = []
for i, vector_id in enumerate(ids):
entry = {
"id": vector_id,
"vector": embeddings_list[i],
}
# Add metadata fields
if metadatas and i < len(metadatas):
metadata = metadatas[i]
# Add common metadata fields
if "text" in metadata:
entry["text"] = metadata["text"]
if "file_id" in metadata:
entry["file_id"] = metadata["file_id"]
if "uuid" in metadata:
entry["chunk_uuid"] = metadata["uuid"]
data.append(entry)
# Insert data into Milvus
await asyncio.to_thread(
self.client.insert,
collection_name=collection,
data=data
)
# Load collection for searching (Milvus requires this)
await asyncio.to_thread(
self.client.load_collection,
collection_name=collection
)
self.ap.logger.info(f"Added {len(ids)} embeddings to Milvus collection '{collection}'")
async def search(
self, collection: str, query_embedding: list[float], k: int = 5
) -> Dict[str, Any]:
"""Search for similar vectors in Milvus collection
Args:
collection: Collection name
query_embedding: Query vector
k: Number of top results to return
Returns:
Dictionary with search results in Chroma-compatible format
"""
await self.get_or_create_collection(collection)
# Perform search
search_params = {
"metric_type": "COSINE",
"params": {}
}
results = await asyncio.to_thread(
self.client.search,
collection_name=collection,
data=[query_embedding],
limit=k,
search_params=search_params,
output_fields=["text", "file_id", "chunk_uuid"]
)
# Convert results to Chroma-compatible format
# Milvus returns: [[ {id, distance, entity: {...}} ]]
ids = []
distances = []
metadatas = []
if results and len(results) > 0:
for hit in results[0]:
ids.append(hit.get("id", ""))
distances.append(hit.get("distance", 0.0))
# Build metadata from entity fields
entity = hit.get("entity", {})
metadata = {}
if "text" in entity:
metadata["text"] = entity["text"]
if "file_id" in entity:
metadata["file_id"] = entity["file_id"]
if "chunk_uuid" in entity:
metadata["uuid"] = entity["chunk_uuid"]
metadatas.append(metadata)
# Return in Chroma-compatible format (nested lists)
result = {
"ids": [ids],
"distances": [distances],
"metadatas": [metadatas]
}
self.ap.logger.info(
f"Milvus search in '{collection}' returned {len(ids)} results"
)
return result
async def delete_by_file_id(self, collection: str, file_id: str) -> None:
"""Delete vectors from collection by file_id
Args:
collection: Collection name
file_id: File ID to filter deletion
"""
await self.get_or_create_collection(collection)
# Delete entities matching the file_id
await asyncio.to_thread(
self.client.delete,
collection_name=collection,
filter=f'file_id == "{file_id}"'
)
self.ap.logger.info(
f"Deleted embeddings from Milvus collection '{collection}' with file_id: {file_id}"
)
async def delete_collection(self, collection: str):
"""Delete a Milvus collection
Args:
collection: Collection name to delete
"""
if collection in self._collections:
del self._collections[collection]
# Check if collection exists before attempting deletion
has_collection = await asyncio.to_thread(
self.client.has_collection, collection_name=collection
)
if has_collection:
await asyncio.to_thread(
self.client.drop_collection, collection_name=collection
)
self.ap.logger.info(f"Deleted Milvus collection '{collection}'")
else:
self.ap.logger.warning(f"Milvus collection '{collection}' not found")