DB-GPT/dbgpt/model/llm_out/hf_chat_llm.py
2024-06-28 13:33:57 +08:00

68 lines
2.0 KiB
Python

import logging
from threading import Thread
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer, TextIteratorStreamer
logger = logging.getLogger(__name__)
@torch.inference_mode()
def huggingface_chat_generate_stream(
model: AutoModelForCausalLM,
tokenizer: AutoTokenizer,
params,
device,
context_len=4096,
):
prompt = params["prompt"]
temperature = float(params.get("temperature", 0.7))
top_p = float(params.get("top_p", 1.0))
echo = params.get("echo", False)
max_new_tokens = int(params.get("max_new_tokens", 2048))
stop_token_ids = params.get("stop_token_ids", [])
do_sample = params.get("do_sample", True)
custom_stop_words = params.get("custom_stop_words", [])
input_ids = tokenizer(prompt).input_ids
# input_ids = input_ids.to(device)
if model.config.is_encoder_decoder:
max_src_len = context_len
else: # truncate
max_src_len = context_len - max_new_tokens - 1
input_ids = input_ids[-max_src_len:]
input_echo_len = len(input_ids)
input_ids = torch.as_tensor([input_ids], device=device)
streamer = TextIteratorStreamer(
tokenizer, skip_prompt=not echo, skip_special_tokens=True
)
base_kwargs = {
"max_length": context_len,
"temperature": temperature,
"streamer": streamer,
"top_p": top_p,
}
if stop_token_ids:
base_kwargs["eos_token_id"] = stop_token_ids
if do_sample is not None:
base_kwargs["do_sample"] = do_sample
logger.info(
f"Predict with parameters: {base_kwargs}\ncustom_stop_words: {custom_stop_words}"
)
generate_kwargs = {"input_ids": input_ids, **base_kwargs}
thread = Thread(target=model.generate, kwargs=generate_kwargs)
thread.start()
out = ""
for new_text in streamer:
out += new_text
if custom_stop_words:
for stop_word in custom_stop_words:
if out.endswith(stop_word):
out = out[: -len(stop_word)]
yield out