handler.py

from typing import  Dict, List, Any
import base64
from PIL import Image
from io import BytesIO
from diffusers.pipelines.stable_diffusion import StableDiffusionSafetyChecker
from diffusers import StableDiffusionPipeline

import torch


# # set device
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
if device.type != 'cuda':
    raise ValueError("need to run on GPU")
# set mixed precision dtype
dtype = torch.bfloat16 if torch.cuda.get_device_capability()[0] == 8 else torch.float16

class EndpointHandler():
     def __init__(self, path=""):
         self.stable_diffusion_id = "Lykon/dreamshaper-8"
         self.pipe = StableDiffusionPipeline.from_pretrained(self.stable_diffusion_id,torch_dtype=dtype,safety_checker=StableDiffusionSafetyChecker.from_pretrained("CompVis/stable-diffusion-safety-checker", torch_dtype=dtype)).to(device.type)

         self.generator = torch.Generator(device=device.type).manual_seed(3)

     def __call__(self, data: Any) -> List[List[Dict[str, float]]]:
#         """
#         :param data: A dictionary contains `inputs` and optional `image` field.
#         :return: A dictionary with `image` field contains image in base64.
#         """
         prompt = data.pop("inputs", None)
         num_inference_steps = data.pop("num_inference_steps", 30)
         guidance_scale = data.pop("guidance_scale", 7.4)
         negative_prompt = data.pop("negative_prompt", None)
         height = data.pop("height", None)
         width = data.pop("width", None)

        # run inference pipeline
         out = self.pipe(
            prompt=prompt, 
            negative_prompt=negative_prompt,
            num_inference_steps=num_inference_steps, 
            guidance_scale=guidance_scale,
            num_images_per_prompt=1,
            height=height,
            width=width,
            generator=self.generator
        )

        
         # return first generate PIL image
         return out.images[0]