LLaMA-Factory/src/llmtuner/chat/chat_model.py
hiyouga 4a0be64ae6 fix imports
Former-commit-id: bbbce1f516840f722247edd37057d16502ea0557
2023-11-15 16:47:45 +08:00

133 lines
5.1 KiB
Python

import torch
from dataclasses import dataclass
from typing import Any, Dict, Generator, List, Literal, Optional, Tuple
from threading import Thread
from transformers import GenerationConfig, TextIteratorStreamer
from llmtuner.data.template import get_template_and_fix_tokenizer
from llmtuner.extras.misc import get_logits_processor
from llmtuner.model import dispatch_model, get_infer_args, load_model_and_tokenizer
@dataclass
class Response:
response_text: str
response_length: int
prompt_length: int
finish_reason: Literal["stop", "length"]
class ChatModel:
def __init__(self, args: Optional[Dict[str, Any]] = None) -> None:
model_args, data_args, finetuning_args, self.generating_args = get_infer_args(args)
self.model, self.tokenizer = load_model_and_tokenizer(model_args, finetuning_args)
self.tokenizer.padding_side = "left"
self.model = dispatch_model(self.model)
self.template = get_template_and_fix_tokenizer(data_args.template, self.tokenizer)
self.system_prompt = data_args.system_prompt
def _process_args(
self,
query: str,
history: Optional[List[Tuple[str, str]]] = None,
system: Optional[str] = None,
**input_kwargs
) -> Tuple[Dict[str, Any], int]:
system = system or self.system_prompt
prompt, _ = self.template.encode_oneturn(
tokenizer=self.tokenizer, query=query, resp="", history=history, system=system
)
prompt_length = len(prompt)
input_ids = torch.tensor([prompt], device=self.model.device)
do_sample = input_kwargs.pop("do_sample", None)
temperature = input_kwargs.pop("temperature", None)
top_p = input_kwargs.pop("top_p", None)
top_k = input_kwargs.pop("top_k", None)
num_return_sequences = input_kwargs.pop("num_return_sequences", None)
repetition_penalty = input_kwargs.pop("repetition_penalty", None)
max_length = input_kwargs.pop("max_length", None)
max_new_tokens = input_kwargs.pop("max_new_tokens", None)
generating_args = self.generating_args.to_dict()
generating_args.update(dict(
do_sample=do_sample if do_sample is not None else generating_args["do_sample"],
temperature=temperature or generating_args["temperature"],
top_p=top_p or generating_args["top_p"],
top_k=top_k or generating_args["top_k"],
num_return_sequences=num_return_sequences or 1,
repetition_penalty=repetition_penalty or generating_args["repetition_penalty"],
eos_token_id=[self.tokenizer.eos_token_id] + self.tokenizer.additional_special_tokens_ids,
pad_token_id=self.tokenizer.pad_token_id
))
if isinstance(num_return_sequences, int) and num_return_sequences > 1:
generating_args["do_sample"] = True
if max_length:
generating_args.pop("max_new_tokens", None)
generating_args["max_length"] = max_length
if max_new_tokens:
generating_args.pop("max_length", None)
generating_args["max_new_tokens"] = max_new_tokens
gen_kwargs = dict(
inputs=input_ids,
generation_config=GenerationConfig(**generating_args),
logits_processor=get_logits_processor()
)
return gen_kwargs, prompt_length
@torch.inference_mode()
def chat(
self,
query: str,
history: Optional[List[Tuple[str, str]]] = None,
system: Optional[str] = None,
**input_kwargs
) -> List[Response]:
r"""
Args: query, history, system, **input_kwargs
Returns: [(response_text, prompt_length, response_length)] * n (default n=1)
"""
gen_kwargs, prompt_length = self._process_args(query, history, system, **input_kwargs)
generate_output = self.model.generate(**gen_kwargs)
response_ids = generate_output[:, prompt_length:]
response = self.tokenizer.batch_decode(
response_ids, skip_special_tokens=True, clean_up_tokenization_spaces=True
)
results = []
for i in range(len(response)):
eos_index = (response_ids[i] == self.tokenizer.eos_token_id).nonzero()
response_length = (eos_index[0].item() + 1) if len(eos_index) else len(response_ids[i])
results.append(Response(
response_text=response[i],
response_length=response_length,
prompt_length=prompt_length,
finish_reason="stop" if len(eos_index) else "length"
))
return results
@torch.inference_mode()
def stream_chat(
self,
query: str,
history: Optional[List[Tuple[str, str]]] = None,
system: Optional[str] = None,
**input_kwargs
) -> Generator[str, None, None]:
gen_kwargs, _ = self._process_args(query, history, system, **input_kwargs)
streamer = TextIteratorStreamer(self.tokenizer, timeout=60.0, skip_prompt=True, skip_special_tokens=True)
gen_kwargs["streamer"] = streamer
thread = Thread(target=self.model.generate, kwargs=gen_kwargs)
thread.start()
yield from streamer