95 lines
3.2 KiB
Python
95 lines
3.2 KiB
Python
import argparse
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import json
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import time
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from pathlib import Path
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from typing import AsyncGenerator
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import uvicorn
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from fastapi import BackgroundTasks, FastAPI, Request
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from fastapi.responses import JSONResponse, Response, StreamingResponse
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from vllm.engine.arg_utils import AsyncEngineArgs
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from vllm.engine.async_llm_engine import AsyncLLMEngine
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from vllm.sampling_params import SamplingParams
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from vllm.utils import random_uuid
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TIMEOUT_KEEP_ALIVE = 5 # seconds.
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TIMEOUT_TO_PREVENT_DEADLOCK = 1 # seconds.
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app = FastAPI()
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served_model = None
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@app.get("/model")
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async def generate(request: Request) -> Response:
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return JSONResponse({'model': served_model, 'timestamp': int(time.time())})
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@app.post("/generate")
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async def generate(request: Request) -> Response:
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"""Generate completion for the request.
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The request should be a JSON object with the following fields:
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- prompt: the prompt to use for the generation.
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- stream: whether to stream the results or not.
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- other fields: the sampling parameters (See `SamplingParams` for details).
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"""
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request_dict = await request.json()
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prompt = request_dict.pop("prompt")
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stream = request_dict.pop("stream", False)
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sampling_params = SamplingParams(**request_dict)
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request_id = random_uuid()
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results_generator = engine.generate(prompt, sampling_params, request_id)
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# Streaming case
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async def stream_results() -> AsyncGenerator[bytes, None]:
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async for request_output in results_generator:
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prompt = request_output.prompt
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text_outputs = [
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prompt + output.text for output in request_output.outputs
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]
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ret = {"text": text_outputs}
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yield (json.dumps(ret) + "\0").encode("utf-8")
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async def abort_request() -> None:
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await engine.abort(request_id)
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if stream:
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background_tasks = BackgroundTasks()
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# Abort the request if the client disconnects.
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background_tasks.add_task(abort_request)
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return StreamingResponse(stream_results(), background=background_tasks)
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# Non-streaming case
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final_output = None
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async for request_output in results_generator:
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if await request.is_disconnected():
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# Abort the request if the client disconnects.
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await engine.abort(request_id)
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return Response(status_code=499)
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final_output = request_output
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assert final_output is not None
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prompt = final_output.prompt
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text_outputs = [prompt + output.text for output in final_output.outputs]
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ret = {"text": text_outputs}
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return JSONResponse(ret)
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if __name__ == "__main__":
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parser = argparse.ArgumentParser()
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parser.add_argument("--host", type=str, default="localhost")
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parser.add_argument("--port", type=int, default=8000)
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parser = AsyncEngineArgs.add_cli_args(parser)
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args = parser.parse_args()
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served_model = Path(args.model).name
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engine_args = AsyncEngineArgs.from_cli_args(args)
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engine = AsyncLLMEngine.from_engine_args(engine_args)
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uvicorn.run(app,
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host=args.host,
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port=args.port,
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log_level="debug",
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timeout_keep_alive=TIMEOUT_KEEP_ALIVE)
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