dify/api/services/hit_testing_service.py
2023-08-12 00:57:00 +08:00

134 lines
4.1 KiB
Python

import logging
import time
from typing import List
import numpy as np
from flask import current_app
from langchain.embeddings.base import Embeddings
from langchain.schema import Document
from sklearn.manifold import TSNE
from core.embedding.cached_embedding import CacheEmbedding
from core.index.vector_index.vector_index import VectorIndex
from core.model_providers.model_factory import ModelFactory
from extensions.ext_database import db
from models.account import Account
from models.dataset import Dataset, DocumentSegment, DatasetQuery
class HitTestingService:
@classmethod
def retrieve(cls, dataset: Dataset, query: str, account: Account, limit: int = 10) -> dict:
if dataset.available_document_count == 0 or dataset.available_document_count == 0:
return {
"query": {
"content": query,
"tsne_position": {'x': 0, 'y': 0},
},
"records": []
}
embedding_model = ModelFactory.get_embedding_model(
tenant_id=dataset.tenant_id
)
embeddings = CacheEmbedding(embedding_model)
vector_index = VectorIndex(
dataset=dataset,
config=current_app.config,
embeddings=embeddings
)
start = time.perf_counter()
documents = vector_index.search(
query,
search_type='similarity_score_threshold',
search_kwargs={
'k': 10
}
)
end = time.perf_counter()
logging.debug(f"Hit testing retrieve in {end - start:0.4f} seconds")
dataset_query = DatasetQuery(
dataset_id=dataset.id,
content=query,
source='hit_testing',
created_by_role='account',
created_by=account.id
)
db.session.add(dataset_query)
db.session.commit()
return cls.compact_retrieve_response(dataset, embeddings, query, documents)
@classmethod
def compact_retrieve_response(cls, dataset: Dataset, embeddings: Embeddings, query: str, documents: List[Document]):
text_embeddings = [
embeddings.embed_query(query)
]
text_embeddings.extend(embeddings.embed_documents([document.page_content for document in documents]))
tsne_position_data = cls.get_tsne_positions_from_embeddings(text_embeddings)
query_position = tsne_position_data.pop(0)
i = 0
records = []
for document in documents:
index_node_id = document.metadata['doc_id']
segment = db.session.query(DocumentSegment).filter(
DocumentSegment.dataset_id == dataset.id,
DocumentSegment.enabled == True,
DocumentSegment.status == 'completed',
DocumentSegment.index_node_id == index_node_id
).first()
if not segment:
i += 1
continue
record = {
"segment": segment,
"score": document.metadata['score'],
"tsne_position": tsne_position_data[i]
}
records.append(record)
i += 1
return {
"query": {
"content": query,
"tsne_position": query_position,
},
"records": records
}
@classmethod
def get_tsne_positions_from_embeddings(cls, embeddings: list):
embedding_length = len(embeddings)
if embedding_length <= 1:
return [{'x': 0, 'y': 0}]
concatenate_data = np.array(embeddings).reshape(embedding_length, -1)
# concatenate_data = np.concatenate(embeddings)
perplexity = embedding_length / 2 + 1
if perplexity >= embedding_length:
perplexity = max(embedding_length - 1, 1)
tsne = TSNE(n_components=2, perplexity=perplexity, early_exaggeration=12.0)
data_tsne = tsne.fit_transform(concatenate_data)
tsne_position_data = []
for i in range(len(data_tsne)):
tsne_position_data.append({'x': float(data_tsne[i][0]), 'y': float(data_tsne[i][1])})
return tsne_position_data