dify/api/services/retrieval_service.py

119 lines
4.6 KiB
Python

from typing import Optional
from core.index.vector_index.vector_index import VectorIndex
from core.model_manager import ModelManager
from core.model_runtime.entities.model_entities import ModelType
from core.model_runtime.errors.invoke import InvokeAuthorizationError
from core.rerank.rerank import RerankRunner
from extensions.ext_database import db
from flask import Flask, current_app
from langchain.embeddings.base import Embeddings
from models.dataset import Dataset
default_retrieval_model = {
'search_method': 'semantic_search',
'reranking_enable': False,
'reranking_model': {
'reranking_provider_name': '',
'reranking_model_name': ''
},
'top_k': 2,
'score_threshold_enabled': False
}
class RetrievalService:
@classmethod
def embedding_search(cls, flask_app: Flask, dataset_id: str, query: str,
top_k: int, score_threshold: Optional[float], reranking_model: Optional[dict],
all_documents: list, search_method: str, embeddings: Embeddings):
with flask_app.app_context():
dataset = db.session.query(Dataset).filter(
Dataset.id == dataset_id
).first()
vector_index = VectorIndex(
dataset=dataset,
config=current_app.config,
embeddings=embeddings
)
documents = vector_index.search(
query,
search_type='similarity_score_threshold',
search_kwargs={
'k': top_k,
'score_threshold': score_threshold,
'filter': {
'group_id': [dataset.id]
}
}
)
if documents:
if reranking_model and search_method == 'semantic_search':
try:
model_manager = ModelManager()
rerank_model_instance = model_manager.get_model_instance(
tenant_id=dataset.tenant_id,
provider=reranking_model['reranking_provider_name'],
model_type=ModelType.RERANK,
model=reranking_model['reranking_model_name']
)
except InvokeAuthorizationError:
return
rerank_runner = RerankRunner(rerank_model_instance)
all_documents.extend(rerank_runner.run(
query=query,
documents=documents,
score_threshold=score_threshold,
top_n=len(documents)
))
else:
all_documents.extend(documents)
@classmethod
def full_text_index_search(cls, flask_app: Flask, dataset_id: str, query: str,
top_k: int, score_threshold: Optional[float], reranking_model: Optional[dict],
all_documents: list, search_method: str, embeddings: Embeddings):
with flask_app.app_context():
dataset = db.session.query(Dataset).filter(
Dataset.id == dataset_id
).first()
vector_index = VectorIndex(
dataset=dataset,
config=current_app.config,
embeddings=embeddings
)
documents = vector_index.search_by_full_text_index(
query,
search_type='similarity_score_threshold',
top_k=top_k
)
if documents:
if reranking_model and search_method == 'full_text_search':
try:
model_manager = ModelManager()
rerank_model_instance = model_manager.get_model_instance(
tenant_id=dataset.tenant_id,
provider=reranking_model['reranking_provider_name'],
model_type=ModelType.RERANK,
model=reranking_model['reranking_model_name']
)
except InvokeAuthorizationError:
return
rerank_runner = RerankRunner(rerank_model_instance)
all_documents.extend(rerank_runner.run(
query=query,
documents=documents,
score_threshold=score_threshold,
top_n=len(documents)
))
else:
all_documents.extend(documents)