ForcePilot/backend/package/yuxi/models/rerank.py
2026-05-27 19:56:26 +08:00

195 lines
7.0 KiB
Python

import asyncio
from abc import ABC, abstractmethod
from collections.abc import Iterable, Sequence
from typing import Any
import aiohttp
import numpy as np
from yuxi.services.model_cache import model_cache
from yuxi.utils import get_docker_safe_url, logger
def sigmoid(x):
return 1 / (1 + np.exp(-x))
class BaseReranker(ABC):
def __init__(self, model_name, api_key, base_url, **kwargs):
self.url = get_docker_safe_url(base_url)
self.model = model_name
self.api_key = api_key
self.headers = {"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"}
self.session: aiohttp.ClientSession | None = None
self.timeout = aiohttp.ClientTimeout(total=30)
self.parameters: dict[str, Any] = dict(kwargs.get("parameters", {}))
async def _ensure_session(self) -> None:
if self.session is None or self.session.closed:
self.session = aiohttp.ClientSession(headers=self.headers, timeout=self.timeout)
@abstractmethod
def _build_payload(self, query: str, documents: list[str], max_length: int) -> dict[str, Any]:
raise NotImplementedError
@abstractmethod
def _extract_results(self, result: dict[str, Any]) -> list[dict[str, Any]]:
raise NotImplementedError
async def acompute_score(
self,
sentence_pairs: Sequence[Sequence[str]],
batch_size: int = 32,
max_length: int = 512,
normalize: bool = True,
) -> list[float]:
if not sentence_pairs or len(sentence_pairs) < 2:
return []
query, sentences = sentence_pairs[0], sentence_pairs[1]
documents = [sentences] if isinstance(sentences, str) else list(sentences)
if not documents:
return []
await self._ensure_session()
all_scores: list[float] = []
batch_size = max(1, int(batch_size))
total_batches = (len(documents) + batch_size - 1) // batch_size
for batch_no, start in enumerate(range(0, len(documents), batch_size), start=1):
batch = documents[start : start + batch_size]
try:
scores = await self._batch_rerank(query, batch, max_length=max_length)
all_scores.extend(scores)
logger.debug(f"Reranking batch {batch_no}/{total_batches} completed")
except Exception as exc:
logger.error(f"Reranking batch {batch_no} failed: {exc}")
all_scores.extend([0.5] * len(batch))
if normalize:
all_scores = [float(sigmoid(score)) for score in all_scores]
return all_scores
async def _batch_rerank(self, query: str, documents: Iterable[str], max_length: int) -> list[float]:
docs = list(documents)
if not docs:
return []
payload = self._build_payload(query, docs, max_length)
await self._ensure_session()
assert self.session is not None
try:
async with self.session.post(self.url, json=payload) as response:
response.raise_for_status()
result: dict[str, Any] = await response.json()
except TimeoutError as exc:
total_timeout = self.timeout.total if self.timeout else 0.0
logger.error(f"Reranking request timeout after {total_timeout:.1f}s")
raise exc
except aiohttp.ClientError as exc:
logger.error(f"Reranking request failed: {exc}")
raise exc
processed = sorted(self._extract_results(result), key=lambda item: item.get("index", 0))
return [float(entry.get("relevance_score", 0.0)) for entry in processed]
def compute_score(self, sentence_pairs, batch_size=256, max_length=512, normalize=False):
try:
_ = asyncio.get_running_loop()
except RuntimeError:
return asyncio.run(self.acompute_score(sentence_pairs, batch_size, max_length, normalize))
raise RuntimeError("compute_score cannot be used while an event loop is running. Use acompute_score instead.")
async def test_connection(self) -> tuple[bool, str]:
try:
scores = await self._batch_rerank("test query", ["test document"], max_length=128)
if scores:
return True, "连接正常"
return False, "响应无效"
except Exception as e:
error_msg = str(e)
logger.error(f"Rerank connection test failed: {error_msg}")
return False, error_msg
finally:
await self.aclose()
async def aclose(self) -> None:
if self.session and not self.session.closed:
await self.session.close()
def __del__(self) -> None:
if self.session and not self.session.closed:
try:
loop = asyncio.get_event_loop()
except RuntimeError:
asyncio.run(self.aclose())
return
if loop.is_closed():
asyncio.run(self.aclose())
elif not loop.is_running():
loop.run_until_complete(self.aclose())
class OpenAIReranker(BaseReranker):
def _build_payload(self, query: str, documents: list[str], max_length: int) -> dict[str, Any]:
return {
"model": self.model,
"query": query,
"documents": documents,
"max_chunks_per_doc": max_length,
}
def _extract_results(self, result: dict[str, Any]) -> list[dict[str, Any]]:
return list(result.get("results", []))
class DashscopeReranker(BaseReranker):
def _build_payload(self, query: str, documents: list[str], max_length: int) -> dict[str, Any]:
params = {"top_n": len(documents), "return_documents": False}
instruct = self.parameters.get("instruct")
if instruct:
params["instruct"] = instruct
return {
"model": self.model,
"input": {"query": query, "documents": documents},
"parameters": params,
}
def _extract_results(self, result: dict[str, Any]) -> list[dict[str, Any]]:
return list(result.get("output", {}).get("results", []))
def get_reranker(model_id: str, **kwargs):
info = model_cache.get_model_info(model_id)
if not info:
raise ValueError(f"Unknown reranker model spec: {model_id}")
if info.model_type != "rerank":
raise ValueError(f"Model {model_id} is not a rerank model (type={info.model_type})")
if not info.api_key:
raise ValueError(f"{info.display_name} api_key is required")
parameters = dict(info.extra.get("parameters") or {})
parameters.update(kwargs.pop("parameters", {}) or {})
reranker_kwargs = {**kwargs, "parameters": parameters}
protocol = info.extra.get("rerank_protocol") or info.extra.get("protocol")
if protocol == "dashscope":
return DashscopeReranker(
model_name=info.model_id,
api_key=info.api_key,
base_url=info.base_url,
**reranker_kwargs,
)
return OpenAIReranker(
model_name=info.model_id,
api_key=info.api_key,
base_url=info.base_url,
**reranker_kwargs,
)