add reranker (#679)

python/reranker/bge-reranker-base/Dockerfile

+FROM pytorch/pytorch:2.0.1-cuda11.7-cudnn8-runtime
+
+# please download the model from https://huggingface.co/BAAI/bge-reranker-base and put it in the same directory as Dockerfile
+COPY ./bge-reranker-base ./bge-reranker-base
+
+COPY app.py Dockerfile requirement.txt .
+
+RUN python3 -m pip install -r requirement.txt
+
+ENTRYPOINT python3 app.py

python/reranker/bge-reranker-base/README.md

+
+## 推荐配置
+
+推荐配置如下：
+
+{{< table "table-hover table-striped-columns" >}}
+| 类型 | 内存 | 显存 | 硬盘空间 | 启动命令 |
+|------|---------|---------|----------|--------------------------|
+| base | >=4GB | >=3GB | >=8GB | python app.py |
+{{< /table >}}
+
+## 部署
+
+### 环境要求
+
+- Python 3.10.11
+- CUDA 11.7
+- 科学上网环境
+
+### 源码部署
+
+1. 根据上面的环境配置配置好环境，具体教程自行 GPT；
+2. 下载 [python 文件](app.py)
+3. 在命令行输入命令 `pip install -r requirments.txt`；
+4. 按照[https://huggingface.co/BAAI/bge-reranker-base](https://huggingface.co/BAAI/bge-reranker-base)下载模型仓库到app.py同级目录
+5. 添加环境变量 `export ACCESS_TOKEN=XXXXXX` 配置 token，这里的 token 只是加一层验证，防止接口被人盗用，默认值为 `ACCESS_TOKEN` ；
+6. 执行命令 `python app.py`。
+
+然后等待模型下载，直到模型加载完毕为止。如果出现报错先问 GPT。
+
+启动成功后应该会显示如下地址：
+
+![](/imgs/chatglm2.png)
+
+> 这里的 `http://0.0.0.0:6006` 就是连接地址。
+
+### docker 部署
+
+**镜像和端口**
+
++ 镜像名: `luanshaotong/reranker:v0.1`  
++ 端口号: 6006
+
+```
+# 设置安全凭证（即oneapi中的渠道密钥）
+通过环境变量ACCESS_TOKEN引入，默认值：ACCESS_TOKEN。
+有关docker环境变量引入的方法请自寻教程，此处不再赘述。
+```

python/reranker/bge-reranker-base/app.py

+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+@Time: 2023/11/7 22:45
+@Author: zhidong
+@File: reranker.py
+@Desc: 
+"""
+import os
+import numpy as np
+import logging
+import uvicorn
+import datetime
+from fastapi import FastAPI, Security, HTTPException
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from FlagEmbedding import FlagReranker
+from pydantic import Field, BaseModel, validator
+from typing import Optional, List
+
+def response(code, msg, data=None):
+    time = str(datetime.datetime.now())
+    if data is None:
+        data = []
+    result = {
+        "code": code,
+        "message": msg,
+        "data": data,
+        "time": time
+    }
+    return result
+
+def success(data=None, msg=''):
+    return 
+
+
+class Inputs(BaseModel):
+    id: str
+    text: Optional[str]
+
+
+class QADocs(BaseModel):
+    query: Optional[str]
+    inputs: Optional[List[Inputs]]
+
+
+class Singleton(type):
+    def __call__(cls, *args, **kwargs):
+        if not hasattr(cls, '_instance'):
+            cls._instance = super().__call__(*args, **kwargs)
+        return cls._instance
+
+
+RERANK_MODEL_PATH = os.path.join(os.path.dirname(__file__), "bge-reranker-base")
+
+class Reranker(metaclass=Singleton):
+    def __init__(self, model_path):
+        self.reranker = FlagReranker(model_path,
+                                     use_fp16=False)
+
+    def compute_score(self, pairs: List[List[str]]):
+        if len(pairs) > 0:
+            result = self.reranker.compute_score(pairs)
+            if isinstance(result, float):
+                result = [result]
+            return result
+        else:
+            return None
+
+
+class Chat(object):
+    def __init__(self, rerank_model_path: str = RERANK_MODEL_PATH):
+        self.reranker = Reranker(rerank_model_path)
+
+    def fit_query_answer_rerank(self, query_docs: QADocs) -> List:
+        if query_docs is None or len(query_docs.inputs) == 0:
+            return []
+        new_docs = []
+        pair = []
+        for answer in query_docs.inputs:
+            pair.append([query_docs.query, answer.text])
+        scores = self.reranker.compute_score(pair)
+        for index, score in enumerate(scores):
+            new_docs.append({"id": query_docs.inputs[index].id, "score": 1 / (1 + np.exp(-score))})
+        new_docs = list(sorted(new_docs, key=lambda x: x["score"], reverse=True))
+        return new_docs
+
+app = FastAPI()
+security = HTTPBearer()
+env_bearer_token = 'ACCESS_TOKEN'
+
+@app.post('/api/v1/rerank')
+async def handle_post_request(docs: QADocs, credentials: HTTPAuthorizationCredentials = Security(security)):
+    token = credentials.credentials
+    if env_bearer_token is not None and token != env_bearer_token:
+        raise HTTPException(status_code=401, detail="Invalid token")
+    chat = Chat()
+    qa_docs_with_rerank = chat.fit_query_answer_rerank(docs)
+    return response(200, msg="重排成功", data=qa_docs_with_rerank)
+
+if __name__ == "__main__":
+    token = os.getenv("ACCESS_TOKEN")
+    if token is not None:
+        env_bearer_token = token
+    try:
+        uvicorn.run(app, host='0.0.0.0', port=6006)
+    except Exception as e:
+        print(f"API启动失败！\n报错：\n{e}")
\ No newline at end of file

python/reranker/bge-reranker-base/requirement.txt

+fastapi==0.104.1
+FlagEmbedding==1.1.5
+pydantic==1.10.13
+uvicorn==0.17.6
+itsdangerous
+protobuf