168 lines
5.4 KiB
Python
168 lines
5.4 KiB
Python
# coding=utf-8
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# Implements API for ChatGLM2-6B in OpenAI's format. (https://platform.openai.com/docs/api-reference/chat)
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# Usage: python openai_api.py
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# Visit http://localhost:8000/docs for documents.
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import time
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import torch
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import uvicorn
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from pydantic import BaseModel, Field
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from fastapi import FastAPI, HTTPException
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from contextlib import asynccontextmanager
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from starlette.responses import StreamingResponse
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from typing import Any, Dict, List, Literal, Optional, Union
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from transformers import AutoTokenizer, AutoModel
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@asynccontextmanager
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async def lifespan(app: FastAPI): # collects GPU memory
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yield
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if torch.cuda.is_available():
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torch.cuda.empty_cache()
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torch.cuda.ipc_collect()
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app = FastAPI(lifespan=lifespan)
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class ModelCard(BaseModel):
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id: str
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object: str = "model"
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created: int = Field(default_factory=lambda: int(time.time()))
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owned_by: str = "owner"
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root: Optional[str] = None
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parent: Optional[str] = None
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permission: Optional[list] = None
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class ModelList(BaseModel):
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object: str = "list"
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data: List[ModelCard] = []
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class ChatMessage(BaseModel):
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role: Literal["user", "assistant", "system"]
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content: str
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class DeltaMessage(BaseModel):
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role: Optional[Literal["user", "assistant", "system"]] = None
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content: Optional[str] = None
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class ChatCompletionRequest(BaseModel):
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model: str
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messages: List[ChatMessage]
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temperature: Optional[float] = None
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top_p: Optional[float] = None
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max_length: Optional[int] = None
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stream: Optional[bool] = False
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class ChatCompletionResponseChoice(BaseModel):
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index: int
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message: ChatMessage
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finish_reason: Literal["stop", "length"]
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class ChatCompletionResponseStreamChoice(BaseModel):
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index: int
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delta: DeltaMessage
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finish_reason: Optional[Literal["stop", "length"]]
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class ChatCompletionResponse(BaseModel):
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model: str
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object: Literal["chat.completion", "chat.completion.chunk"]
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choices: List[Union[ChatCompletionResponseChoice, ChatCompletionResponseStreamChoice]]
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created: Optional[int] = Field(default_factory=lambda: int(time.time()))
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@app.get("/v1/models", response_model=ModelList)
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async def list_models():
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global model_args
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model_card = ModelCard(id="gpt-3.5-turbo")
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return ModelList(data=[model_card])
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@app.post("/v1/chat/completions", response_model=ChatCompletionResponse)
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async def create_chat_completion(request: ChatCompletionRequest):
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global model, tokenizer
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if request.messages[-1].role != "user":
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raise HTTPException(status_code=400, detail="Invalid request")
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query = request.messages[-1].content
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prev_messages = request.messages[:-1]
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if len(prev_messages) > 0 and prev_messages[0].role == "system":
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query = prev_messages.pop(0).content + query
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history = []
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if len(prev_messages) % 2 == 0:
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for i in range(0, len(prev_messages), 2):
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if prev_messages[i].role == "user" and prev_messages[i+1].role == "assistant":
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history.append([prev_messages[i].content, prev_messages[i+1].content])
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if request.stream:
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generate = predict(query, history, request.model)
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return StreamingResponse(generate, media_type="text/event-stream")
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response, _ = model.chat(tokenizer, query, history=history)
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choice_data = ChatCompletionResponseChoice(
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index=0,
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message=ChatMessage(role="assistant", content=response),
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finish_reason="stop"
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)
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return ChatCompletionResponse(model=request.model, choices=[choice_data], object="chat.completion")
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async def predict(query: str, history: List[List[str]], model_id: str):
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global model, tokenizer
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choice_data = ChatCompletionResponseStreamChoice(
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index=0,
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delta=DeltaMessage(role="assistant"),
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finish_reason=None
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)
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chunk = ChatCompletionResponse(model=model_id, choices=[choice_data], object="chat.completion.chunk")
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yield "data: {}\n\n".format(chunk.json(exclude_unset=True, ensure_ascii=False))
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current_length = 0
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for new_response, _ in model.stream_chat(tokenizer, query, history):
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if len(new_response) == current_length:
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continue
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new_text = new_response[current_length:]
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current_length = len(new_response)
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choice_data = ChatCompletionResponseStreamChoice(
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index=0,
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delta=DeltaMessage(content=new_text),
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finish_reason=None
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)
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chunk = ChatCompletionResponse(model=model_id, choices=[choice_data], object="chat.completion.chunk")
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yield "data: {}\n\n".format(chunk.json(exclude_unset=True, ensure_ascii=False))
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choice_data = ChatCompletionResponseStreamChoice(
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index=0,
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delta=DeltaMessage(),
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finish_reason="stop"
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)
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chunk = ChatCompletionResponse(model=model_id, choices=[choice_data], object="chat.completion.chunk")
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yield "data: {}\n\n".format(chunk.json(exclude_unset=True, ensure_ascii=False))
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if __name__ == "__main__":
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tokenizer = AutoTokenizer.from_pretrained("THUDM/chatglm2-6b", trust_remote_code=True)
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model = AutoModel.from_pretrained("THUDM/chatglm2-6b", trust_remote_code=True).cuda()
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# 多显卡支持,使用下面三行代替上面两行,将num_gpus改为你实际的显卡数量
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# model_path = "THUDM/chatglm2-6b"
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# tokenizer = AutoTokenizer.from_pretrained(model_path, trust_remote_code=True)
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# model = load_model_on_gpus(model_path, num_gpus=2)
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model.eval()
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uvicorn.run(app, host='0.0.0.0', port=8000, workers=1)
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