dify/api/core/embedding/cached_embedding.py

83 lines
3.2 KiB
Python

import logging
from typing import List
import numpy as np
from langchain.embeddings.base import Embeddings
from sqlalchemy.exc import IntegrityError
from core.model_providers.models.embedding.base import BaseEmbedding
from extensions.ext_database import db
from libs import helper
from models.dataset import Embedding
class CacheEmbedding(Embeddings):
def __init__(self, embeddings: BaseEmbedding):
self._embeddings = embeddings
def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Embed search docs."""
# use doc embedding cache or store if not exists
text_embeddings = [None for _ in range(len(texts))]
embedding_queue_indices = []
for i, text in enumerate(texts):
hash = helper.generate_text_hash(text)
embedding = db.session.query(Embedding).filter_by(model_name=self._embeddings.name, hash=hash).first()
if embedding:
text_embeddings[i] = embedding.get_embedding()
else:
embedding_queue_indices.append(i)
if embedding_queue_indices:
try:
embedding_results = self._embeddings.client.embed_documents([texts[i] for i in embedding_queue_indices])
except Exception as ex:
raise self._embeddings.handle_exceptions(ex)
for i, indice in enumerate(embedding_queue_indices):
hash = helper.generate_text_hash(texts[indice])
try:
embedding = Embedding(model_name=self._embeddings.name, hash=hash)
vector = embedding_results[i]
normalized_embedding = (vector / np.linalg.norm(vector)).tolist()
text_embeddings[indice] = normalized_embedding
embedding.set_embedding(normalized_embedding)
db.session.add(embedding)
db.session.commit()
except IntegrityError:
db.session.rollback()
continue
except:
logging.exception('Failed to add embedding to db')
continue
return text_embeddings
def embed_query(self, text: str) -> List[float]:
"""Embed query text."""
# use doc embedding cache or store if not exists
hash = helper.generate_text_hash(text)
embedding = db.session.query(Embedding).filter_by(model_name=self._embeddings.name, hash=hash).first()
if embedding:
return embedding.get_embedding()
try:
embedding_results = self._embeddings.client.embed_query(text)
embedding_results = (embedding_results / np.linalg.norm(embedding_results)).tolist()
except Exception as ex:
raise self._embeddings.handle_exceptions(ex)
try:
embedding = Embedding(model_name=self._embeddings.name, hash=hash)
embedding.set_embedding(embedding_results)
db.session.add(embedding)
db.session.commit()
except IntegrityError:
db.session.rollback()
except:
logging.exception('Failed to add embedding to db')
return embedding_results