Files
LangBot/pkg/rag/knowledge/services/embedder.py
2025-07-13 23:04:03 +08:00

90 lines
4.1 KiB
Python

from __future__ import annotations
import asyncio
import logging
import numpy as np
from typing import List
from sqlalchemy.orm import Session
from pkg.rag.knowledge.services.base_service import BaseService
from pkg.rag.knowledge.services.database import Chunk, SessionLocal
from pkg.rag.knowledge.services.chroma_manager import ChromaIndexManager
from sqlalchemy.orm import declarative_base, sessionmaker
from ....core import app
from ....entity.persistence import model as persistence_model
import sqlalchemy
from ....provider.modelmgr.requester import RuntimeEmbeddingModel
base = declarative_base()
logger = logging.getLogger(__name__)
class Embedder(BaseService):
def __init__(self, ap: app.Application, chroma_manager: ChromaIndexManager = None) -> None:
super().__init__()
self.logger = logging.getLogger(self.__class__.__name__)
self.chroma_manager = chroma_manager
self.ap = ap
def _db_save_chunks_sync(self, session: Session, file_id: int, chunks_texts: List[str]):
"""
Saves chunks to the relational database and returns the created Chunk objects.
This function assumes it's called within a context where the session
will be committed/rolled back and closed by the caller.
"""
self.logger.debug(f"Saving {len(chunks_texts)} chunks for file_id {file_id} to DB (sync).")
chunk_objects = []
for text in chunks_texts:
chunk = Chunk(file_id=file_id, text=text)
session.add(chunk)
chunk_objects.append(chunk)
session.flush() # This populates the .id attribute for each new chunk object
self.logger.debug(f"Successfully added {len(chunk_objects)} chunk entries to DB.")
return chunk_objects
async def embed_and_store(self, file_id: int, chunks: List[str], embedding_model: RuntimeEmbeddingModel) -> List[Chunk]:
if not embedding_model:
raise RuntimeError("Embedding model not loaded. Please check Embedder initialization.")
session = SessionLocal() # Start a session that will live for the whole operation
chunk_objects = []
try:
# 1. Save chunks to the relational database first to get their IDs
# We call _db_save_chunks_sync directly without _run_sync's session management
# because we manage the session here across multiple async calls.
chunk_objects = await asyncio.to_thread(self._db_save_chunks_sync, session, file_id, chunks)
session.commit() # Commit chunks to make their IDs permanent and accessible
if not chunk_objects:
self.logger.warning(f"No chunk objects created for file_id {file_id}. Skipping embedding and Chroma storage.")
return []
# get the embeddings for the chunks
embeddings = []
i = 0
while i <len(chunks):
chunk = chunks[i]
result = await embedding_model.requester.invoke_embedding(
model=embedding_model,
input_text=chunk,
)
embeddings.append(result)
i += 1
embeddings_np = np.array(embeddings, dtype=np.float32)
self.logger.info("Saving embeddings to Chroma...")
chunk_ids = [c.id for c in chunk_objects]
file_ids_for_chroma = [file_id] * len(chunk_ids)
await self._run_sync( # Use _run_sync for the Chroma operation, as it's a sync call
self.chroma_manager.add_embeddings_sync,
file_ids_for_chroma, chunk_ids, embeddings_np, chunks # Pass original chunks texts for documents
)
self.logger.info(f"Successfully saved {len(chunk_objects)} embeddings to Chroma.")
return chunk_objects
except Exception as e:
session.rollback() # Rollback on any error
self.logger.error(f"Failed to process and store data for file_id {file_id}: {e}", exc_info=True)
raise # Re-raise the exception to propagate it
finally:
session.close() # Ensure the session is always closed