app.py

import spaces
from transformers import AutoModelForCausalLM, AutoTokenizer, TextIteratorStreamer
import torch
import gradio as gr
import logging
from huggingface_hub import login
import os

from threading import Thread

# Status: Breaks during generation

logging.basicConfig(level=logging.DEBUG)

HF_TOKEN = os.environ.get("HF_TOKEN", None)
login(token=HF_TOKEN)

models_available = [
    "NousResearch/Meta-Llama-3.1-8B-Instruct",
    "mistralai/Mistral-7B-Instruct-v0.3",
]

tokenizer_a, model_a = None, None
tokenizer_b, model_b = None, None
torch_dtype = torch.bfloat16

def apply_chat_template(messages, add_generation_prompt=False):
    """
    Function to apply the chat template manually for each message in a list.
    messages: List of dictionaries, each containing a 'role' and 'content'.
    """
    pharia_template = """<|begin_of_text|>"""
    role_map = {
        "system": "<|start_header_id|>system<|end_header_id|>\n",
        "user": "<|start_header_id|>user<|end_header_id|>\n",
        "assistant": "<|start_header_id|>assistant<|end_header_id|>\n",
    }
    
    # Iterate through the messages and apply the template for each role
    for message in messages:
        role = message["role"]
        content = message["content"]
        pharia_template += role_map.get(role, "") + content + "<|eot_id|>\n"
    
    # Add the assistant generation prompt if required
    if add_generation_prompt:
        pharia_template += "<|start_header_id|>assistant<|end_header_id|>\n"
    
    return pharia_template


def load_model_a(model_id):
    global tokenizer_a, model_a, model_id_a
    model_id_a = model_id # need to access model_id with tokenizer
    tokenizer_a = AutoTokenizer.from_pretrained(model_id)
    logging.debug(f"***** model A eos_token: {tokenizer_a.eos_token}")
    model_a = AutoModelForCausalLM.from_pretrained(
        model_id,
        torch_dtype=torch_dtype,
        device_map="auto",
        trust_remote_code=True,
    ).eval()
    return gr.update(label=model_id)
    
def load_model_b(model_id):
    global tokenizer_b, model_b, model_id_b
    model_id_b = model_id
    tokenizer_b = AutoTokenizer.from_pretrained(model_id)
    logging.debug(f"***** model B eos_token: {tokenizer_b.eos_token}")
    model_b = AutoModelForCausalLM.from_pretrained(
        model_id,
        torch_dtype=torch_dtype,
        device_map="auto",
        trust_remote_code=True,
    ).eval()
    model_b.tie_weights()
    return gr.update(label=model_id)

@spaces.GPU()
def generate_both(system_prompt, input_text, chatbot_a, chatbot_b, max_new_tokens=2048, temperature=0.2, top_p=0.9, repetition_penalty=1.1):

    text_streamer_a = TextIteratorStreamer(tokenizer_a, skip_prompt=True)
    text_streamer_b = TextIteratorStreamer(tokenizer_b, skip_prompt=True)

    system_prompt_list = [{"role": "system", "content": system_prompt}] if system_prompt else []
    input_text_list = [{"role": "user", "content": input_text}]

    chat_history_a = []
    for user, assistant in chatbot_a:
        chat_history_a.append({"role": "user", "content": user})
        chat_history_a.append({"role": "assistant", "content": assistant})

    chat_history_b = []
    for user, assistant in chatbot_b:
        chat_history_b.append({"role": "user", "content": user})
        chat_history_b.append({"role": "assistant", "content": assistant})
    
    new_messages_a = system_prompt_list + chat_history_a + input_text_list
    new_messages_b = system_prompt_list + chat_history_b + input_text_list

    input_ids_a = tokenizer_a.apply_chat_template(
        new_messages_a,
        add_generation_prompt=True,
        return_tensors="pt"
    ).to(model_a.device)

    input_ids_b = tokenizer_b.apply_chat_template(
        new_messages_b,
        add_generation_prompt=True,
        return_tensors="pt"
    ).to(model_b.device)

    generation_kwargs_a = dict(
        input_ids=input_ids_a,
        streamer=text_streamer_a,
        max_new_tokens=max_new_tokens,
        pad_token_id=tokenizer_a.eos_token_id,
        do_sample=True,
        temperature=temperature,
        top_p=top_p,
        repetition_penalty=repetition_penalty,
    )
    generation_kwargs_b = dict(
        input_ids=input_ids_b,
        streamer=text_streamer_b,
        max_new_tokens=max_new_tokens,
        pad_token_id=tokenizer_b.eos_token_id,
        do_sample=True,
        temperature=temperature,
        top_p=top_p,
        repetition_penalty=repetition_penalty,
    )

    thread_a = Thread(target=model_a.generate, kwargs=generation_kwargs_a)
    thread_b = Thread(target=model_b.generate, kwargs=generation_kwargs_b)

    thread_a.start()
    thread_b.start()

    chatbot_a.append([input_text, ""])
    chatbot_b.append([input_text, ""])

    finished_a = False
    finished_b = False

    while not (finished_a and finished_b):
        if not finished_a:
            try:
                text_a = next(text_streamer_a)
                if tokenizer_a.eos_token in text_a:
                    eot_location = text_a.find(tokenizer_a.eos_token)
                    text_a = text_a[:eot_location]
                    finished_a = True
                chatbot_a[-1][-1] += text_a
                yield chatbot_a, chatbot_b
            except StopIteration:
                finished_a = True

        if not finished_b:
            try:
                text_b = next(text_streamer_b)
                if tokenizer_b.eos_token in text_b:
                    eot_location = text_b.find(tokenizer_b.eos_token)
                    text_b = text_b[:eot_location]
                    finished_b = True
                chatbot_b[-1][-1] += text_b
                yield chatbot_a, chatbot_b
            except StopIteration:
                finished_b = True

    return chatbot_a, chatbot_b

def clear():
    return [], []

arena_notes = """## Important Notes:
- Sometimes an error may occur when generating the response, in this case, please try again.
"""

with gr.Blocks() as demo:
    with gr.Column():
        gr.HTML("<center><h1>🤖le Royale</h1></center>")
        gr.Markdown(arena_notes)
        system_prompt = gr.Textbox(lines=1, label="System Prompt", value="You are a helpful chatbot. Write a Nike style ad headline about the shame of being second best", show_copy_button=True)
        with gr.Row(variant="panel"):
            with gr.Column():
                model_dropdown_a = gr.Dropdown(label="Model A", choices=models_available, value=None)
                chatbot_a = gr.Chatbot(label="Model A", rtl=True, likeable=True, show_copy_button=True, height=500)
            with gr.Column():
                model_dropdown_b = gr.Dropdown(label="Model B", choices=models_available, value=None)
                chatbot_b = gr.Chatbot(label="Model B", rtl=True, likeable=True, show_copy_button=True, height=500)
        with gr.Row(variant="panel"):
            with gr.Column(scale=1):
                submit_btn = gr.Button(value="Generate", variant="primary")
                clear_btn = gr.Button(value="Clear", variant="secondary")
            input_text = gr.Textbox(lines=1, label="Output", value="", scale=3, show_copy_button=True)
        with gr.Accordion(label="Generation Configurations", open=False):
            max_new_tokens = gr.Slider(minimum=128, maximum=4096, value=2048, label="Max New Tokens", step=128)
            temperature = gr.Slider(minimum=0.0, maximum=1.0, value=0.7, label="Temperature", step=0.01)
            top_p = gr.Slider(minimum=0.0, maximum=1.0, value=1.0, label="Top-p", step=0.01)
            repetition_penalty = gr.Slider(minimum=0.1, maximum=2.0, value=1.1, label="Repetition Penalty", step=0.1)

    model_dropdown_a.change(load_model_a, inputs=[model_dropdown_a], outputs=[chatbot_a])
    model_dropdown_b.change(load_model_b, inputs=[model_dropdown_b], outputs=[chatbot_b])

    input_text.submit(generate_both, inputs=[system_prompt, input_text, chatbot_a, chatbot_b, max_new_tokens, temperature, top_p, repetition_penalty], outputs=[chatbot_a, chatbot_b])
    submit_btn.click(generate_both, inputs=[system_prompt, input_text, chatbot_a, chatbot_b, max_new_tokens, temperature, top_p, repetition_penalty], outputs=[chatbot_a, chatbot_b])
    clear_btn.click(clear, outputs=[chatbot_a, chatbot_b])

if __name__ == "__main__":
    demo.queue().launch()