dify/api/services/hit_testing_service.py
2023-05-15 08:51:32 +08:00

131 lines
4.1 KiB
Python

import logging
import time
from typing import List
import numpy as np
from llama_index.data_structs.node_v2 import NodeWithScore
from llama_index.indices.query.schema import QueryBundle
from llama_index.indices.vector_store import GPTVectorStoreIndexQuery
from sklearn.manifold import TSNE
from core.docstore.empty_docstore import EmptyDocumentStore
from core.index.vector_index import VectorIndex
from extensions.ext_database import db
from models.account import Account
from models.dataset import Dataset, DocumentSegment, DatasetQuery
from services.errors.index import IndexNotInitializedError
class HitTestingService:
@classmethod
def retrieve(cls, dataset: Dataset, query: str, account: Account, limit: int = 10) -> dict:
index = VectorIndex(dataset=dataset).query_index
if not index:
raise IndexNotInitializedError()
index_query = GPTVectorStoreIndexQuery(
index_struct=index.index_struct,
service_context=index.service_context,
vector_store=index.query_context.get('vector_store'),
docstore=EmptyDocumentStore(),
response_synthesizer=None,
similarity_top_k=limit
)
query_bundle = QueryBundle(
query_str=query,
custom_embedding_strs=[query],
)
query_bundle.embedding = index.service_context.embed_model.get_agg_embedding_from_queries(
query_bundle.embedding_strs
)
start = time.perf_counter()
nodes = index_query.retrieve(query_bundle=query_bundle)
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, query_bundle, nodes)
@classmethod
def compact_retrieve_response(cls, dataset: Dataset, query_bundle: QueryBundle, nodes: List[NodeWithScore]):
embeddings = [
query_bundle.embedding
]
for node in nodes:
embeddings.append(node.node.embedding)
tsne_position_data = cls.get_tsne_positions_from_embeddings(embeddings)
query_position = tsne_position_data.pop(0)
i = 0
records = []
for node in nodes:
index_node_id = node.node.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": node.score,
"tsne_position": tsne_position_data[i]
}
records.append(record)
i += 1
return {
"query": {
"content": query_bundle.query_str,
"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