app-img2img.py

import asyncio
import json
import logging
import traceback
from pydantic import BaseModel

from fastapi import FastAPI, WebSocket, HTTPException, WebSocketDisconnect
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import StreamingResponse, JSONResponse
from fastapi.staticfiles import StaticFiles

from diffusers import AutoPipelineForImage2Image, AutoencoderTiny
from compel import Compel
import torch

try:
    import intel_extension_for_pytorch as ipex
except:
    pass
from PIL import Image
import numpy as np
import gradio as gr
import io
import uuid
import os
import time
import psutil

MAX_QUEUE_SIZE = int(os.environ.get("MAX_QUEUE_SIZE", 0))
TIMEOUT = float(os.environ.get("TIMEOUT", 0))
SAFETY_CHECKER = os.environ.get("SAFETY_CHECKER", None)
TORCH_COMPILE = os.environ.get("TORCH_COMPILE", None)   

WIDTH = 512
HEIGHT = 512
# disable tiny autoencoder for better quality speed tradeoff
USE_TINY_AUTOENCODER = True

# check if MPS is available OSX only M1/M2/M3 chips
mps_available = hasattr(torch.backends, "mps") and torch.backends.mps.is_available()
xpu_available = hasattr(torch, "xpu") and torch.xpu.is_available()
device = torch.device(
    "cuda" if torch.cuda.is_available() else "xpu" if xpu_available else "cpu"
)
torch_device = device

# change to torch.float16 to save GPU memory
torch_dtype = torch.float32

print(f"TIMEOUT: {TIMEOUT}")
print(f"SAFETY_CHECKER: {SAFETY_CHECKER}")
print(f"MAX_QUEUE_SIZE: {MAX_QUEUE_SIZE}")
print(f"device: {device}")

if mps_available:
    device = torch.device("mps")
    torch_device = "cpu"
    torch_dtype = torch.float32

if SAFETY_CHECKER == "True":
    pipe = AutoPipelineForImage2Image.from_pretrained(
        "SimianLuo/LCM_Dreamshaper_v7",
    )
else:
    pipe = AutoPipelineForImage2Image.from_pretrained(
        "SimianLuo/LCM_Dreamshaper_v7",
        safety_checker=None,
    )

if USE_TINY_AUTOENCODER:
    pipe.vae = AutoencoderTiny.from_pretrained(
        "madebyollin/taesd", torch_dtype=torch_dtype, use_safetensors=True
    )
pipe.set_progress_bar_config(disable=True)
pipe.to(device=torch_device, dtype=torch_dtype).to(device)
pipe.unet.to(memory_format=torch.channels_last)

if psutil.virtual_memory().total < 64 * 1024**3:
    pipe.enable_attention_slicing()

if TORCH_COMPILE:
    pipe.unet = torch.compile(pipe.unet, mode="reduce-overhead", fullgraph=True)
    pipe.vae = torch.compile(pipe.vae, mode="reduce-overhead", fullgraph=True)

    pipe(prompt="warmup", image=[Image.new("RGB", (512, 512))])

compel_proc = Compel(
    tokenizer=pipe.tokenizer,
    text_encoder=pipe.text_encoder,
    truncate_long_prompts=False,
)
user_queue_map = {}


class InputParams(BaseModel):
    seed: int = 2159232
    prompt: str
    guidance_scale: float = 8.0
    strength: float = 0.5
    steps: int = 4
    lcm_steps: int = 50
    width: int = WIDTH
    height: int = HEIGHT

def predict(input_image: Image.Image, params: InputParams, prompt_embeds: torch.Tensor = None):
    generator = torch.manual_seed(params.seed)
    results = pipe(
        prompt_embeds=prompt_embeds,
        generator=generator,
        image=input_image,
        strength=params.strength,
        num_inference_steps=params.steps,
        guidance_scale=params.guidance_scale,
        width=params.width,
        height=params.height,
        original_inference_steps=params.lcm_steps,
        output_type="pil",
    )
    nsfw_content_detected = (
        results.nsfw_content_detected[0]
        if "nsfw_content_detected" in results
        else False
    )
    if nsfw_content_detected:
        return None
    return results.images[0]


app = FastAPI()
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    if MAX_QUEUE_SIZE > 0 and len(user_queue_map) >= MAX_QUEUE_SIZE:
        print("Server is full")
        await websocket.send_json({"status": "error", "message": "Server is full"})
        await websocket.close()
        return

    try:
        uid = str(uuid.uuid4())
        print(f"New user connected: {uid}")
        await websocket.send_json(
            {"status": "success", "message": "Connected", "userId": uid}
        )
        user_queue_map[uid] = {"queue": asyncio.Queue()}
        await websocket.send_json(
            {"status": "start", "message": "Start Streaming", "userId": uid}
        )
        await handle_websocket_data(websocket, uid)
    except WebSocketDisconnect as e:
        logging.error(f"WebSocket Error: {e}, {uid}")
        traceback.print_exc()
    finally:
        print(f"User disconnected: {uid}")
        queue_value = user_queue_map.pop(uid, None)
        queue = queue_value.get("queue", None)
        if queue:
            while not queue.empty():
                try:
                    queue.get_nowait()
                except asyncio.QueueEmpty:
                    continue


@app.get("/queue_size")
async def get_queue_size():
    queue_size = len(user_queue_map)
    return JSONResponse({"queue_size": queue_size})


@app.get("/stream/{user_id}")
async def stream(user_id: uuid.UUID):
    uid = str(user_id)
    try:
        user_queue = user_queue_map[uid]
        queue = user_queue["queue"]

        async def generate():
            last_prompt: str = None
            prompt_embeds: torch.Tensor = None
            while True:
                data = await queue.get()
                input_image = data["image"]
                params = data["params"]
                if input_image is None:
                    continue
                # avoid recalculate prompt embeds
                if last_prompt != params.prompt:
                    print("new prompt")
                    prompt_embeds = compel_proc(params.prompt)
                    last_prompt = params.prompt

                image = predict(
                    input_image,
                    params,
                    prompt_embeds,
                )
                if image is None:
                    continue
                frame_data = io.BytesIO()
                image.save(frame_data, format="JPEG")
                frame_data = frame_data.getvalue()
                if frame_data is not None and len(frame_data) > 0:
                    yield b"--frame\r\nContent-Type: image/jpeg\r\n\r\n" + frame_data + b"\r\n"

                await asyncio.sleep(1.0 / 120.0)

        return StreamingResponse(
            generate(), media_type="multipart/x-mixed-replace;boundary=frame"
        )
    except Exception as e:
        logging.error(f"Streaming Error: {e}, {user_queue_map}")
        traceback.print_exc()
        return HTTPException(status_code=404, detail="User not found")


async def handle_websocket_data(websocket: WebSocket, user_id: uuid.UUID):
    uid = str(user_id)
    user_queue = user_queue_map[uid]
    queue = user_queue["queue"]
    if not queue:
        return HTTPException(status_code=404, detail="User not found")
    last_time = time.time()
    try:
        while True:
            data = await websocket.receive_bytes()
            params = await websocket.receive_json()
            params = InputParams(**params)
            pil_image = Image.open(io.BytesIO(data))

            while not queue.empty():
                try:
                    queue.get_nowait()
                except asyncio.QueueEmpty:
                    continue
            await queue.put({"image": pil_image, "params": params})
            if TIMEOUT > 0 and time.time() - last_time > TIMEOUT:
                await websocket.send_json(
                    {
                        "status": "timeout",
                        "message": "Your session has ended",
                        "userId": uid,
                    }
                )
                await websocket.close()
                return

    except Exception as e:
        logging.error(f"Error: {e}")
        traceback.print_exc()


app.mount("/", StaticFiles(directory="img2img", html=True), name="public")