handler.py

import argparse
import torch
from typing import Dict, List, Any

from llava.constants import IMAGE_TOKEN_INDEX, DEFAULT_IMAGE_TOKEN, DEFAULT_IM_START_TOKEN, DEFAULT_IM_END_TOKEN
from llava.conversation import conv_templates, SeparatorStyle
from llava.model.builder import load_pretrained_model
from llava.utils import disable_torch_init
from llava.mm_utils import process_images, tokenizer_image_token, get_model_name_from_path, KeywordsStoppingCriteria
from configs import *


from PIL import Image

import requests
import base64
from PIL import Image
from io import BytesIO
from transformers import TextStreamer



class EndpointHandler():
    def __init__(self, path = MODEL_PATH):
        disable_torch_init()
        self.model_path = MODEL_PATH
        self.model_base = MODEL_BASE
        self.model_name = get_model_name_from_path(self.model_path)
        self.device = "cuda" if torch.cuda.is_available() else "cpu"
        self.tokenizer, self.model, self.image_processor, context_len = load_pretrained_model(
            model_path=self.model_path, 
            model_name=self.model_name, 
            load_8bit=LOAD_8BIT, 
            load_4bit=LOAD_4BIT, 
            device=self.device,
            )

        if "llama-2" in self.model_name.lower():
            self.conv_mode = "llava_llama_2"
        elif "v1" in self.model_name.lower():
            self.conv_mode = "llava_v1"
        elif "mpt" in self.model_name.lower():
            self.conv_mode = "mpt"
        else:
            self.conv_mode = "llava_v0"
        
        # conv_mode = CONV_MODE

        # self.conv = conv_templates[conv_mode].copy()
        # if "mpt" in self.model_name.lower():
        #     self.roles = ("user", "assistant")
        # else:
        #     self.roles = self.conv.roles

    def __call__(self, data: Dict[str, Any]) -> List[Dict[str, Any]]:
        
        self.conv = conv_templates[self.conv_mode].copy()
        if "mpt" in self.model_name.lower():
            self.roles = ("user", "assistant")
        else:
            self.roles = self.conv.roles

        # getting encoded image from the data
        image_encoded = data.pop("inputs", data)
        # getting the manual prompt  from the data
        text = data["text"]

        # decoding the base64 to image
        image = self.decode_base64_image(image_encoded)
        
        # converting the mode of the image to RGB if it is not that
        if image.mode != "RGB":
            image = image.convert("RGB")

        model_config = {"image_aspect_ratio": IMAGE_ASPECT_RATIO}
        # preprocessing the image
        image_tensor = process_images([image], self.image_processor, model_config)
        # converting to torch.tensor
        image_tensor = image_tensor.to(self.model.device, dtype = torch.float16)

        while True:    
            
            # getting the predefined prompt from the `prompts` file
            inp = text #prompt_.user_prompt
            
            if image is not None:
                # first message
                if self.model.config.mm_use_im_start_end:
                    inp = DEFAULT_IM_START_TOKEN + DEFAULT_IMAGE_TOKEN + DEFAULT_IM_END_TOKEN + '\n' + inp
                else:
                    inp = DEFAULT_IMAGE_TOKEN + '\n' + inp
                self.conv.append_message(self.conv.roles[0], inp)
                image = None
            else:
                # later messages
                self.conv.append_message(self.conv.roles[0], inp)
            self.conv.append_message(self.conv.roles[1], None)
            prompt = self.conv.get_prompt()

            input_ids = tokenizer_image_token(prompt, self.tokenizer, IMAGE_TOKEN_INDEX, return_tensors="pt").unsqueeze(0).cuda()
            stop_str = self.conv.sep if self.conv.sep_style != SeparatorStyle.TWO else self.conv.sep2
            keywords = [stop_str]
            stopping_criteria = KeywordsStoppingCriteria(keywords, self.tokenizer, input_ids)
            streamer = TextStreamer(self.tokenizer, skip_prompt=True, skip_special_tokens=True)

            with torch.inference_mode():
                output_ids = self.model.generate(
                    input_ids,
                    images=image_tensor,
                    do_sample=True,
                    temperature=TEMPERATURE,
                    max_new_tokens=MAX_NEW_TOKENS,
                    streamer=streamer,
                    use_cache=True,
                    stopping_criteria=[stopping_criteria]
                )
            
            # print(len(output_ids) if type(output_ids) is list  else output_ids.shape)
            outputs = self.tokenizer.decode(output_ids[0, input_ids.shape[1]:]).strip()
            # self.conv.messages[-1][-1] = outputs

            return outputs
            # return f"{input_ids.shape},{output_ids.shape}"
        
    def decode_base64_image(self, image_string):
        base64_image = base64.b64decode(image_string)
        buffer = BytesIO(base64_image)
        image = Image.open(buffer)
        return image