Qwen-7B-main / openai_api.py
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# coding=utf-8
# Implements API for Qwen-7B in OpenAI's format. (https://platform.openai.com/docs/api-reference/chat)
# Usage: python openai_api.py
# Visit http://localhost:8000/docs for documents.
from argparse import ArgumentParser
import time
import torch
import uvicorn
from pydantic import BaseModel, Field
from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
from typing import Any, Dict, List, Literal, Optional, Union
from transformers import AutoTokenizer, AutoModel, AutoModelForCausalLM
from transformers.generation import GenerationConfig
from sse_starlette.sse import ServerSentEvent, EventSourceResponse
@asynccontextmanager
async def lifespan(app: FastAPI): # collects GPU memory
yield
if torch.cuda.is_available():
torch.cuda.empty_cache()
torch.cuda.ipc_collect()
app = FastAPI(lifespan=lifespan)
app.add_middleware(
CORSMiddleware,
allow_origins=["*"],
allow_credentials=True,
allow_methods=["*"],
allow_headers=["*"],
)
class ModelCard(BaseModel):
id: str
object: str = "model"
created: int = Field(default_factory=lambda: int(time.time()))
owned_by: str = "owner"
root: Optional[str] = None
parent: Optional[str] = None
permission: Optional[list] = None
class ModelList(BaseModel):
object: str = "list"
data: List[ModelCard] = []
class ChatMessage(BaseModel):
role: Literal["user", "assistant", "system"]
content: str
class DeltaMessage(BaseModel):
role: Optional[Literal["user", "assistant", "system"]] = None
content: Optional[str] = None
class ChatCompletionRequest(BaseModel):
model: str
messages: List[ChatMessage]
temperature: Optional[float] = None
top_p: Optional[float] = None
max_length: Optional[int] = None
stream: Optional[bool] = False
class ChatCompletionResponseChoice(BaseModel):
index: int
message: ChatMessage
finish_reason: Literal["stop", "length"]
class ChatCompletionResponseStreamChoice(BaseModel):
index: int
delta: DeltaMessage
finish_reason: Optional[Literal["stop", "length"]]
class ChatCompletionResponse(BaseModel):
model: str
object: Literal["chat.completion", "chat.completion.chunk"]
choices: List[Union[ChatCompletionResponseChoice, ChatCompletionResponseStreamChoice]]
created: Optional[int] = Field(default_factory=lambda: int(time.time()))
@app.get("/v1/models", response_model=ModelList)
async def list_models():
global model_args
model_card = ModelCard(id="gpt-3.5-turbo")
return ModelList(data=[model_card])
@app.post("/v1/chat/completions", response_model=ChatCompletionResponse)
async def create_chat_completion(request: ChatCompletionRequest):
global model, tokenizer
if request.messages[-1].role != "user":
raise HTTPException(status_code=400, detail="Invalid request")
query = request.messages[-1].content
prev_messages = request.messages[:-1]
# Temporarily, the system role does not work as expected. We advise that you write the setups for role-play in your query.
# if len(prev_messages) > 0 and prev_messages[0].role == "system":
# query = prev_messages.pop(0).content + query
history = []
if len(prev_messages) % 2 == 0:
for i in range(0, len(prev_messages), 2):
if prev_messages[i].role == "user" and prev_messages[i+1].role == "assistant":
history.append([prev_messages[i].content, prev_messages[i+1].content])
else:
raise HTTPException(status_code=400, detail="Invalid request.")
else:
raise HTTPException(status_code=400, detail="Invalid request.")
if request.stream:
generate = predict(query, history, request.model)
return EventSourceResponse(generate, media_type="text/event-stream")
response, _ = model.chat(tokenizer, query, history=history)
choice_data = ChatCompletionResponseChoice(
index=0,
message=ChatMessage(role="assistant", content=response),
finish_reason="stop"
)
return ChatCompletionResponse(model=request.model, choices=[choice_data], object="chat.completion")
async def predict(query: str, history: List[List[str]], model_id: str):
global model, tokenizer
choice_data = ChatCompletionResponseStreamChoice(
index=0,
delta=DeltaMessage(role="assistant"),
finish_reason=None
)
chunk = ChatCompletionResponse(model=model_id, choices=[choice_data], object="chat.completion.chunk")
yield "{}".format(chunk.model_dump_json(exclude_unset=True))
current_length = 0
for new_response in model.chat_stream(tokenizer, query, history):
if len(new_response) == current_length:
continue
new_text = new_response[current_length:]
current_length = len(new_response)
choice_data = ChatCompletionResponseStreamChoice(
index=0,
delta=DeltaMessage(content=new_text),
finish_reason=None
)
chunk = ChatCompletionResponse(model=model_id, choices=[choice_data], object="chat.completion.chunk")
yield "{}".format(chunk.model_dump_json(exclude_unset=True))
choice_data = ChatCompletionResponseStreamChoice(
index=0,
delta=DeltaMessage(),
finish_reason="stop"
)
chunk = ChatCompletionResponse(model=model_id, choices=[choice_data], object="chat.completion.chunk")
yield "{}".format(chunk.model_dump_json(exclude_unset=True))
yield '[DONE]'
def _get_args():
parser = ArgumentParser()
parser.add_argument("-c", "--checkpoint-path", type=str, default='QWen/QWen-7B-Chat',
help="Checkpoint name or path, default to %(default)r")
parser.add_argument("--cpu-only", action="store_true", help="Run demo with CPU only")
parser.add_argument("--server-port", type=int, default=8000,
help="Demo server port.")
parser.add_argument("--server-name", type=str, default="127.0.0.1",
help="Demo server name.")
args = parser.parse_args()
return args
if __name__ == "__main__":
args = _get_args()
tokenizer = AutoTokenizer.from_pretrained(
args.checkpoint_path, trust_remote_code=True, resume_download=True,
)
if args.cpu_only:
device_map = "cpu"
else:
device_map = "auto"
model = AutoModelForCausalLM.from_pretrained(
args.checkpoint_path,
device_map=device_map,
trust_remote_code=True,
resume_download=True,
).eval()
model.generation_config = GenerationConfig.from_pretrained(
args.checkpoint_path, trust_remote_code=True, resume_download=True,
)
uvicorn.run(app, host=args.server_name, port=args.server_port, workers=1)