LLMBB-Agent / openai_api.py
vlff李飞飞
update md
2319518
# 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.
import re
import copy
import json
import time
from argparse import ArgumentParser
from contextlib import asynccontextmanager
from typing import Dict, List, Literal, Optional, Union
import torch
import uvicorn
from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, Field
from sse_starlette.sse import EventSourceResponse
from transformers import AutoTokenizer, AutoModelForCausalLM
from transformers.generation import GenerationConfig
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.requests import Request
from starlette.responses import Response
import base64
class BasicAuthMiddleware(BaseHTTPMiddleware):
def __init__(self, app, username: str, password: str):
super().__init__(app)
self.required_credentials = base64.b64encode(f"{username}:{password}".encode()).decode()
async def dispatch(self, request: Request, call_next):
authorization: str = request.headers.get("Authorization")
if authorization:
try:
schema, credentials = authorization.split()
if credentials == self.required_credentials:
return await call_next(request)
except ValueError:
pass
headers = {'WWW-Authenticate': 'Basic'}
return Response(status_code=401, headers=headers)
def _gc(forced: bool = False):
global args
if args.disable_gc and not forced:
return
import gc
gc.collect()
if torch.cuda.is_available():
torch.cuda.empty_cache()
@asynccontextmanager
async def lifespan(app: FastAPI): # collects GPU memory
yield
_gc(forced=True)
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", "function"]
content: Optional[str]
function_call: Optional[Dict] = None
class DeltaMessage(BaseModel):
role: Optional[Literal["user", "assistant", "system"]] = None
content: Optional[str] = None
class ChatCompletionRequest(BaseModel):
model: str
messages: List[ChatMessage]
functions: Optional[List[Dict]] = None
temperature: Optional[float] = None
top_p: Optional[float] = None
max_length: Optional[int] = None
stream: Optional[bool] = False
stop: Optional[List[str]] = None
class ChatCompletionResponseChoice(BaseModel):
index: int
message: ChatMessage
finish_reason: Literal["stop", "length", "function_call"]
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])
# To work around that unpleasant leading-\n tokenization issue!
def add_extra_stop_words(stop_words):
if stop_words:
_stop_words = []
_stop_words.extend(stop_words)
for x in stop_words:
s = x.lstrip("\n")
if s and (s not in _stop_words):
_stop_words.append(s)
return _stop_words
return stop_words
def trim_stop_words(response, stop_words):
if stop_words:
for stop in stop_words:
idx = response.find(stop)
if idx != -1:
response = response[:idx]
return response
TOOL_DESC = """{name_for_model}: Call this tool to interact with the {name_for_human} API. What is the {name_for_human} API useful for? {description_for_model} Parameters: {parameters}"""
REACT_INSTRUCTION = """Answer the following questions as best you can. You have access to the following APIs:
{tools_text}
Use the following format:
Question: the input question you must answer
Thought: you should always think about what to do
Action: the action to take, should be one of [{tools_name_text}]
Action Input: the input to the action
Observation: the result of the action
... (this Thought/Action/Action Input/Observation can be repeated zero or more times)
Thought: I now know the final answer
Final Answer: the final answer to the original input question
Begin!"""
_TEXT_COMPLETION_CMD = object()
#
# Temporarily, the system role does not work as expected.
# We advise that you write the setups for role-play in your query,
# i.e., use the user role instead of the system role.
#
# TODO: Use real system role when the model is ready.
#
def parse_messages(messages, functions):
if all(m.role != "user" for m in messages):
raise HTTPException(
status_code=400,
detail=f"Invalid request: Expecting at least one user message.",
)
messages = copy.deepcopy(messages)
default_system = "You are a helpful assistant."
system = ""
if messages[0].role == "system":
system = messages.pop(0).content.lstrip("\n").rstrip()
if system == default_system:
system = ""
if functions:
tools_text = []
tools_name_text = []
for func_info in functions:
name = func_info.get("name", "")
name_m = func_info.get("name_for_model", name)
name_h = func_info.get("name_for_human", name)
desc = func_info.get("description", "")
desc_m = func_info.get("description_for_model", desc)
tool = TOOL_DESC.format(
name_for_model=name_m,
name_for_human=name_h,
# Hint: You can add the following format requirements in description:
# "Format the arguments as a JSON object."
# "Enclose the code within triple backticks (`) at the beginning and end of the code."
description_for_model=desc_m,
parameters=json.dumps(func_info["parameters"], ensure_ascii=False),
)
tools_text.append(tool)
tools_name_text.append(name_m)
tools_text = "\n\n".join(tools_text)
tools_name_text = ", ".join(tools_name_text)
system += "\n\n" + REACT_INSTRUCTION.format(
tools_text=tools_text,
tools_name_text=tools_name_text,
)
system = system.lstrip("\n").rstrip()
dummy_thought = {
"en": "\nThought: I now know the final answer.\nFinal answer: ",
"zh": "\nThought: 我会作答了。\nFinal answer: ",
}
_messages = messages
messages = []
for m_idx, m in enumerate(_messages):
role, content, func_call = m.role, m.content, m.function_call
if content:
content = content.lstrip("\n").rstrip()
if role == "function":
if (len(messages) == 0) or (messages[-1].role != "assistant"):
raise HTTPException(
status_code=400,
detail=f"Invalid request: Expecting role assistant before role function.",
)
messages[-1].content += f"\nObservation: {content}"
if m_idx == len(_messages) - 1:
messages[-1].content += "\nThought:"
elif role == "assistant":
if len(messages) == 0:
raise HTTPException(
status_code=400,
detail=f"Invalid request: Expecting role user before role assistant.",
)
last_msg = messages[-1].content
last_msg_has_zh = len(re.findall(r"[\u4e00-\u9fff]+", last_msg)) > 0
if func_call is None:
if functions:
content = dummy_thought["zh" if last_msg_has_zh else "en"] + content
else:
f_name, f_args = func_call["name"], func_call["arguments"]
if not content:
if last_msg_has_zh:
content = f"Thought: 我可以使用 {f_name} API。"
else:
content = f"Thought: I can use {f_name}."
content = f"\n{content}\nAction: {f_name}\nAction Input: {f_args}"
if messages[-1].role == "user":
messages.append(
ChatMessage(role="assistant", content=content.lstrip("\n").rstrip())
)
else:
messages[-1].content += content
elif role == "user":
messages.append(
ChatMessage(role="user", content=content.lstrip("\n").rstrip())
)
else:
raise HTTPException(
status_code=400, detail=f"Invalid request: Incorrect role {role}."
)
query = _TEXT_COMPLETION_CMD
if messages[-1].role == "user":
query = messages[-1].content
messages = messages[:-1]
if len(messages) % 2 != 0:
raise HTTPException(status_code=400, detail="Invalid request")
history = [] # [(Q1, A1), (Q2, A2), ..., (Q_last_turn, A_last_turn)]
for i in range(0, len(messages), 2):
if messages[i].role == "user" and messages[i + 1].role == "assistant":
usr_msg = messages[i].content.lstrip("\n").rstrip()
bot_msg = messages[i + 1].content.lstrip("\n").rstrip()
if system and (i == len(messages) - 2):
usr_msg = f"{system}\n\nQuestion: {usr_msg}"
system = ""
for t in dummy_thought.values():
t = t.lstrip("\n")
if bot_msg.startswith(t) and ("\nAction: " in bot_msg):
bot_msg = bot_msg[len(t):]
history.append([usr_msg, bot_msg])
else:
raise HTTPException(
status_code=400,
detail="Invalid request: Expecting exactly one user (or function) role before every assistant role.",
)
if system:
assert query is not _TEXT_COMPLETION_CMD
query = f"{system}\n\nQuestion: {query}"
return query, history
def parse_response(response):
func_name, func_args = "", ""
i = response.rfind("\nAction:")
j = response.rfind("\nAction Input:")
k = response.rfind("\nObservation:")
if 0 <= i < j: # If the text has `Action` and `Action input`,
if k < j: # but does not contain `Observation`,
# then it is likely that `Observation` is omitted by the LLM,
# because the output text may have discarded the stop word.
response = response.rstrip() + "\nObservation:" # Add it back.
k = response.rfind("\nObservation:")
func_name = response[i + len("\nAction:"): j].strip()
func_args = response[j + len("\nAction Input:"): k].strip()
if func_name:
choice_data = ChatCompletionResponseChoice(
index=0,
message=ChatMessage(
role="assistant",
content=response[:i],
function_call={"name": func_name, "arguments": func_args},
),
finish_reason="function_call",
)
return choice_data
z = response.rfind("\nFinal Answer: ")
if z >= 0:
response = response[z + len("\nFinal Answer: "):]
choice_data = ChatCompletionResponseChoice(
index=0,
message=ChatMessage(role="assistant", content=response),
finish_reason="stop",
)
return choice_data
# completion mode, not chat mode
def text_complete_last_message(history, stop_words_ids, gen_kwargs):
im_start = "<|im_start|>"
im_end = "<|im_end|>"
prompt = f"{im_start}system\nYou are a helpful assistant.{im_end}"
for i, (query, response) in enumerate(history):
query = query.lstrip("\n").rstrip()
response = response.lstrip("\n").rstrip()
prompt += f"\n{im_start}user\n{query}{im_end}"
prompt += f"\n{im_start}assistant\n{response}{im_end}"
prompt = prompt[: -len(im_end)]
_stop_words_ids = [tokenizer.encode(im_end)]
if stop_words_ids:
for s in stop_words_ids:
_stop_words_ids.append(s)
stop_words_ids = _stop_words_ids
input_ids = torch.tensor([tokenizer.encode(prompt)]).to(model.device)
output = model.generate(input_ids, stop_words_ids=stop_words_ids, **gen_kwargs).tolist()[0]
output = tokenizer.decode(output, errors="ignore")
assert output.startswith(prompt)
output = output[len(prompt):]
output = trim_stop_words(output, ["<|endoftext|>", im_end])
print(f"<completion>\n{prompt}\n<!-- *** -->\n{output}\n</completion>")
return output
@app.post("/v1/chat/completions", response_model=ChatCompletionResponse)
async def create_chat_completion(request: ChatCompletionRequest):
global model, tokenizer
gen_kwargs = {}
if request.temperature is not None:
if request.temperature < 0.01:
gen_kwargs['top_k'] = 1 # greedy decoding
else:
# Not recommended. Please tune top_p instead.
gen_kwargs['temperature'] = request.temperature
if request.top_p is not None:
gen_kwargs['top_p'] = request.top_p
stop_words = add_extra_stop_words(request.stop)
if request.functions:
stop_words = stop_words or []
if "Observation:" not in stop_words:
stop_words.append("Observation:")
query, history = parse_messages(request.messages, request.functions)
if request.stream:
if request.functions:
raise HTTPException(
status_code=400,
detail="Invalid request: Function calling is not yet implemented for stream mode.",
)
generate = predict(query, history, request.model, stop_words, gen_kwargs)
return generate
# return EventSourceResponse(generate, media_type="text/event-stream")
stop_words_ids = [tokenizer.encode(s) for s in stop_words] if stop_words else None
if query is _TEXT_COMPLETION_CMD:
response = text_complete_last_message(history, stop_words_ids=stop_words_ids, gen_kwargs=gen_kwargs)
else:
response, _ = model.chat(
tokenizer,
query,
history=history,
stop_words_ids=stop_words_ids,
**gen_kwargs
)
print(f"<chat>\n{history}\n{query}\n<!-- *** -->\n{response}\n</chat>")
_gc()
response = trim_stop_words(response, stop_words)
if request.functions:
choice_data = parse_response(response)
else:
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"
)
def _dump_json(data: BaseModel, *args, **kwargs) -> str:
try:
return data.model_dump_json(*args, **kwargs)
except AttributeError: # pydantic<2.0.0
return data.json(*args, **kwargs) # noqa
async def predict(
query: str, history: List[List[str]], model_id: str, stop_words: List[str], gen_kwargs: Dict,
):
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(_dump_json(chunk, exclude_unset=True))
current_length = 0
stop_words_ids = [tokenizer.encode(s) for s in stop_words] if stop_words else None
if stop_words:
# TODO: It's a little bit tricky to trim stop words in the stream mode.
raise HTTPException(
status_code=400,
detail="Invalid request: custom stop words are not yet supported for stream mode.",
)
response_generator = model.chat_stream(
tokenizer, query, history=history, stop_words_ids=stop_words_ids, **gen_kwargs
)
for new_response in response_generator:
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(_dump_json(chunk, 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(_dump_json(chunk, exclude_unset=True))
yield "[DONE]"
_gc()
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(
"--api-auth", help="API authentication credentials"
)
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. Default: 127.0.0.1, which is only visible from the local computer."
" If you want other computers to access your server, use 0.0.0.0 instead.",
)
parser.add_argument("--disable-gc", action="store_true",
help="Disable GC after each response generated.")
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.api_auth:
app.add_middleware(
BasicAuthMiddleware, username=args.api_auth.split(":")[0], password=args.api_auth.split(":")[1]
)
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)