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ymcui--chinese-llama-alpaca/scripts/openai_server_demo/openai_api_server.py
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2026-07-13 13:27:00 +08:00

229 lines
7.8 KiB
Python

import argparse
import os
from fastapi import FastAPI
import uvicorn
parser = argparse.ArgumentParser()
parser.add_argument('--base_model', default=None, type=str, required=True)
parser.add_argument('--lora_model', default=None, type=str,help="If None, perform inference on the base model")
parser.add_argument('--tokenizer_path',default=None,type=str)
parser.add_argument('--gpus', default="0", type=str)
parser.add_argument('--load_in_8bit',action='store_true', help='use 8 bit model')
parser.add_argument('--only_cpu',action='store_true',help='only use CPU for inference')
parser.add_argument('--alpha',type=str,default="1.0", help="The scaling factor of NTK method, can be a float or 'auto'. ")
args = parser.parse_args()
load_in_8bit = args.load_in_8bit
if args.only_cpu is True:
args.gpus = ""
os.environ["CUDA_VISIBLE_DEVICES"] = args.gpus
import torch
import torch.nn.functional as F
from transformers import LlamaForCausalLM, LlamaTokenizer, GenerationConfig
from peft import PeftModel
from patches import apply_attention_patch, apply_ntk_scaling_patch
apply_attention_patch(use_memory_efficient_attention=True)
apply_ntk_scaling_patch(args.alpha)
from openai_api_protocol import (
ChatCompletionRequest,
ChatCompletionResponse,
ChatMessage,
ChatCompletionResponseChoice,
CompletionRequest,
CompletionResponse,
CompletionResponseChoice,
EmbeddingsRequest,
EmbeddingsResponse,
)
load_type = torch.float16
if torch.cuda.is_available():
device = torch.device(0)
else:
device = torch.device('cpu')
if args.tokenizer_path is None:
args.tokenizer_path = args.lora_model
if args.lora_model is None:
args.tokenizer_path = args.base_model
tokenizer = LlamaTokenizer.from_pretrained(args.tokenizer_path)
base_model = LlamaForCausalLM.from_pretrained(
args.base_model,
load_in_8bit=load_in_8bit,
torch_dtype=load_type,
low_cpu_mem_usage=True,
device_map='auto' if not args.only_cpu else None,
)
model_vocab_size = base_model.get_input_embeddings().weight.size(0)
tokenzier_vocab_size = len(tokenizer)
print(f"Vocab of the base model: {model_vocab_size}")
print(f"Vocab of the tokenizer: {tokenzier_vocab_size}")
if model_vocab_size!=tokenzier_vocab_size:
assert tokenzier_vocab_size > model_vocab_size
print("Resize model embeddings to fit tokenizer")
base_model.resize_token_embeddings(tokenzier_vocab_size)
if args.lora_model is not None:
print("loading peft model")
model = PeftModel.from_pretrained(base_model, args.lora_model,torch_dtype=load_type,device_map='auto',)
else:
model = base_model
if device==torch.device('cpu'):
model.float()
model.eval()
def generate_completion_prompt(instruction: str):
"""Generate prompt for completion"""
return f"""Below is an instruction that describes a task. Write a response that appropriately completes the request.
### Instruction:
{instruction}
### Response: """
def generate_chat_prompt(messages: list):
"""Generate prompt for chat completion"""
system_msg = '''Below is an instruction that describes a task. Write a response that appropriately completes the request.'''
for msg in messages:
if msg.role == 'system':
system_msg = msg.content
prompt = f"{system_msg}\n\n"
for msg in messages:
if msg.role == 'system':
continue
if msg.role == 'assistant':
prompt += f"### Response: {msg.content}\n\n"
if msg.role == 'user':
prompt += f"### Instruction:\n{msg.content}\n\n"
prompt += "### Response: "
return prompt
def predict(
input,
max_new_tokens=128,
top_p=0.75,
temperature=0.1,
top_k=40,
num_beams=4,
repetition_penalty=1.0,
do_sample=True,
**kwargs,
):
"""
Main inference method
type(input) == str -> /v1/completions
type(input) == list -> /v1/chat/completions
"""
if isinstance(input, str):
prompt = generate_completion_prompt(input)
else:
prompt = generate_chat_prompt(input)
inputs = tokenizer(prompt, return_tensors="pt")
input_ids = inputs["input_ids"].to(device)
generation_config = GenerationConfig(
temperature=temperature,
top_p=top_p,
top_k=top_k,
num_beams=num_beams,
do_sample=do_sample,
**kwargs,
)
with torch.no_grad():
generation_output = model.generate(
input_ids=input_ids,
generation_config=generation_config,
return_dict_in_generate=True,
output_scores=False,
max_new_tokens=max_new_tokens,
repetition_penalty=float(repetition_penalty),
)
s = generation_output.sequences[0]
output = tokenizer.decode(s, skip_special_tokens=True)
output = output.split("### Response:")[-1].strip()
return output
def get_embedding(input):
"""Get embedding main function"""
with torch.no_grad():
if tokenizer.pad_token == None:
tokenizer.add_special_tokens({'pad_token': '[PAD]'})
encoding = tokenizer(
input, padding=True, return_tensors="pt"
)
input_ids = encoding["input_ids"].to(device)
attention_mask = encoding["attention_mask"].to(device)
model_output = model(
input_ids, attention_mask, output_hidden_states=True
)
data = model_output.hidden_states[-1]
mask = attention_mask.unsqueeze(-1).expand(data.size()).float()
masked_embeddings = data * mask
sum_embeddings = torch.sum(masked_embeddings, dim=1)
seq_length = torch.sum(mask, dim=1)
embedding = sum_embeddings / seq_length
normalized_embeddings = F.normalize(embedding, p=2, dim=1)
ret = normalized_embeddings.squeeze(0).tolist()
return ret
app = FastAPI()
@app.post("/v1/chat/completions")
async def create_chat_completion(request: ChatCompletionRequest):
"""Creates a completion for the chat message"""
msgs = request.messages
if isinstance(msgs, str):
msgs = [ChatMessage(role='user',content=msgs)]
else:
msgs = [ChatMessage(role=x['role'],content=x['message']) for x in msgs]
output = predict(
input=msgs,
max_new_tokens=request.max_tokens,
top_p=request.top_p,
top_k=request.top_k,
temperature=request.temperature,
num_beams=request.num_beams,
repetition_penalty=request.repetition_penalty,
do_sample=request.do_sample,
)
choices = [ChatCompletionResponseChoice(index = i, message = msg) for i, msg in enumerate(msgs)]
choices += [ChatCompletionResponseChoice(index = len(choices), message = ChatMessage(role='assistant',content=output))]
return ChatCompletionResponse(choices = choices)
@app.post("/v1/completions")
async def create_completion(request: CompletionRequest):
"""Creates a completion"""
output = predict(
input=request.prompt,
max_new_tokens=request.max_tokens,
top_p=request.top_p,
top_k=request.top_k,
temperature=request.temperature,
num_beams=request.num_beams,
repetition_penalty=request.repetition_penalty,
do_sample=request.do_sample,
)
choices = [CompletionResponseChoice(index = 0, text = output)]
return CompletionResponse(choices = choices)
@app.post("/v1/embeddings")
async def create_embeddings(request: EmbeddingsRequest):
"""Creates text embedding"""
embedding = get_embedding(request.input)
data = [{
"object": "embedding",
"embedding": embedding,
"index": 0
}]
return EmbeddingsResponse(data=data)
if __name__ == "__main__":
log_config = uvicorn.config.LOGGING_CONFIG
log_config["formatters"]["access"]["fmt"] = "%(asctime)s - %(levelname)s - %(message)s"
log_config["formatters"]["default"]["fmt"] = "%(asctime)s - %(levelname)s - %(message)s"
uvicorn.run(app, host='0.0.0.0', port=19327, workers=1, log_config=log_config)