modeling_clip.py

# coding=utf-8
#
# Code mainly copied from:
# https://github.com/huggingface/transformers/blob/main/src/transformers/models/clip/modeling_clip.py
# and adjusted for Jina CLIP

from functools import partial
from typing import List, Optional, Tuple, Union
from io import BytesIO
import requests
import base64
import numpy as np
import torch
import torch.nn.functional as f
import torch.utils.checkpoint
from torch import nn
from transformers import (
    AutoImageProcessor,
    AutoTokenizer,
    BatchEncoding,
    BatchFeature,
    PreTrainedModel,
    logging,
)
from transformers.models.clip.modeling_clip import (
    CLIPOutput,
    CLIPTextModelOutput,
    CLIPVisionModelOutput,
    clip_loss,
)

try:
    from tqdm.autonotebook import trange

    has_tqdm = True
except ImportError:
    has_tqdm = False

from .configuration_clip import JinaCLIPConfig, JinaCLIPTextConfig, JinaCLIPVisionConfig
from .eva_model import EVAVisionTransformer
from .hf_model import HFTextEncoder

logger = logging.get_logger(__name__)


""" Jina CLIP model implementation """


class LayerNorm(nn.LayerNorm):
    """Subclass torch's LayerNorm (with cast back to input dtype)."""

    def forward(self, x: torch.Tensor):
        origtype = x.dtype
        x = f.layer_norm(x, self.normalized_shape, self.weight, self.bias, self.eps)
        return x.to(origtype)


def _build_text_tower(config: JinaCLIPTextConfig) -> HFTextEncoder:
    return HFTextEncoder(
        model_name_or_path=config.hf_model_name_or_path,
        output_dim=config.embed_dim,
        pooler_type=config.pooler_type,
        proj_type=config.proj_type,
        proj_bias=config.proj_bias,
        pretrained=False,
        output_tokens=False,
        trust_remote_code=True,
        revision=None,
        model_config_kwargs=config.hf_model_config_kwargs,
    )


def _build_vision_tower(config: JinaCLIPVisionConfig) -> EVAVisionTransformer:
    norm_layer = partial(LayerNorm, eps=1e-6)

    if config.fused_layer_norm:
        try:
            from apex.normalization import FusedLayerNorm

            norm_layer = partial(FusedLayerNorm, eps=1e-6)
        except (ModuleNotFoundError, ImportError):
            logger.warning('Please install apex to use fused layer norm, ignoring')

    return EVAVisionTransformer(
        img_size=config.image_size,
        patch_size=config.patch_size,
        num_classes=config.embed_dim,
        use_mean_pooling=False,
        init_values=config.ls_init_value,
        patch_dropout=config.patch_dropout,
        embed_dim=config.width,
        depth=config.layers,
        num_heads=config.width // config.head_width,
        mlp_ratio=config.mlp_ratio,
        qkv_bias=config.qkv_bias,
        drop_path_rate=config.drop_path_rate,
        norm_layer=norm_layer,
        xattn=config.x_attention,
        rope=config.rope_embeddings,
        postnorm=config.post_norm,
        pt_hw_seq_len=config.pt_hw_seq_len,
        intp_freq=config.intp_freq,
        naiveswiglu=config.naive_swiglu,
        subln=config.subln,
        proj_type=config.proj_type,
    )


class JinaCLIPPreTrainedModel(PreTrainedModel):
    """
    An abstract class to handle weights initialization and a simple interface for
    downloading and loading pretrained models.
    """

    config_class = JinaCLIPConfig
    base_model_prefix = 'clip'
    supports_gradient_checkpointing = True

    def _init_weights(self, module):
        """Initialize the weights"""
        if isinstance(module, JinaCLIPModel):
            if isinstance(module.text_projection, nn.Linear):
                nn.init.normal_(
                    module.text_projection.weight,
                    std=module.text_embed_dim**-0.5 * self.config.initializer_factor,
                )
            if isinstance(module.text_projection, nn.Linear):
                nn.init.normal_(
                    module.visual_projection.weight,
                    std=module.vision_embed_dim**-0.5 * self.config.initializer_factor,
                )
        if isinstance(module, nn.LayerNorm):
            module.bias.data.zero_()
            module.weight.data.fill_(1.0)
        if isinstance(module, nn.Linear) and module.bias is not None:
            module.bias.data.zero_()


class JinaCLIPTextModel(JinaCLIPPreTrainedModel):
    config_class = JinaCLIPTextConfig

    def __init__(self, config: JinaCLIPTextConfig):
        super().__init__(config)
        self.text_model = _build_text_tower(config)
        self.post_init()

    def forward(
        self,
        input_ids: Union[None, torch.Tensor, BatchEncoding] = None,
        return_dict: Optional[bool] = None,
        *_,
        **__,
    ) -> Union[Tuple[Optional[torch.FloatTensor], ...], CLIPTextModelOutput]:
        return_dict = (
            return_dict if return_dict is not None else self.config.use_return_dict
        )
        x = input_ids.input_ids if isinstance(input_ids, BatchEncoding) else input_ids
        feats = self.text_model(x=x)
        out = CLIPTextModelOutput(text_embeds=feats)
        return out if return_dict else out.to_tuple()


class JinaCLIPVisionModel(JinaCLIPPreTrainedModel):
    config_class = JinaCLIPVisionConfig
    main_input_name = 'pixel_values'

    def __init__(self, config: JinaCLIPVisionConfig):
        super().__init__(config)
        self.vision_model = _build_vision_tower(config)
        self.post_init()

    def forward(
        self,
        pixel_values: Union[None, torch.FloatTensor, BatchFeature] = None,
        return_dict: Optional[bool] = None,
        *_,
        **__,
    ) -> Union[Tuple[Optional[torch.FloatTensor], ...], CLIPVisionModelOutput]:
        return_dict = (
            return_dict if return_dict is not None else self.config.use_return_dict
        )
        x = (
            pixel_values.pixel_values
            if isinstance(pixel_values, BatchFeature)
            else pixel_values
        )
        feats = self.vision_model(x=x)
        out = CLIPVisionModelOutput(image_embeds=feats)
        return out if return_dict else out.to_tuple()


class JinaCLIPModel(JinaCLIPPreTrainedModel):
    config_class = JinaCLIPConfig

    def __init__(self, config: JinaCLIPConfig):
        super().__init__(config)

        if not isinstance(config.text_config, JinaCLIPTextConfig):
            raise ValueError(
                'Attribute config.text_config is expected to be of type '
                f'JinaCLIPTextConfig but is of type {type(config.text_config)}.'
            )

        if not isinstance(config.vision_config, JinaCLIPVisionConfig):
            raise ValueError(
                'Attribute config.vision_config is expected to be of type '
                f'JinaCLIPVisionConfig but is of type {type(config.vision_config)}.'
            )

        text_config = config.text_config
        vision_config = config.vision_config

        if config.use_text_flash_attn is not None:
            text_config.hf_model_config_kwargs['use_flash_attn'] = config.use_text_flash_attn
        if config.use_vision_xformers is not None:
            vision_config.x_attention = config.use_vision_xformers

        self.add_projections = config.add_projections
        self.projection_dim = config.projection_dim
        self.text_embed_dim = text_config.embed_dim
        self.vision_embed_dim = vision_config.embed_dim

        self.text_model = _build_text_tower(text_config)
        self.vision_model = _build_vision_tower(vision_config)
        self.logit_scale = nn.Parameter(
            torch.tensor(self.config.logit_scale_init_value)
        )

        if self.add_projections:
            self.visual_projection = nn.Linear(
                self.vision_embed_dim, self.projection_dim, bias=False
            )
            self.text_projection = nn.Linear(
                self.text_embed_dim, self.projection_dim, bias=False
            )
        else:
            self.visual_projection = nn.Identity()
            self.text_projection = nn.Identity()

        self.tokenizer = None
        self.preprocess = None
        self.post_init()

    def get_tokenizer(self):
        if not self.tokenizer:
            self.tokenizer = AutoTokenizer.from_pretrained(
                self.config._name_or_path, trust_remote_code=True
            )
        return self.tokenizer

    def get_preprocess(self):
        if not self.preprocess:
            self.preprocess = AutoImageProcessor.from_pretrained(
                self.config._name_or_path, trust_remote_code=True
            )
        return self.preprocess

    def get_text_features(
        self,
        input_ids: Union[None, torch.Tensor, BatchEncoding] = None,
        *_,
        **__,
    ) -> torch.FloatTensor:
        x = input_ids.input_ids if isinstance(input_ids, BatchEncoding) else input_ids
        return self.text_projection(self.text_model(x=x))

    def get_image_features(
        self,
        pixel_values: Union[None, torch.FloatTensor, BatchFeature] = None,
        *_,
        **__,
    ) -> torch.FloatTensor:
        x = (
            pixel_values.pixel_values
            if isinstance(pixel_values, BatchFeature)
            else pixel_values
        )
        return self.visual_projection(self.vision_model(x=x))

    @torch.inference_mode()
    def encode_text(
        self,
        sentences: Union[str, List[str]],
        batch_size: int = 32,
        show_progress_bar: Optional[bool] = None,
        convert_to_numpy: bool = True,
        convert_to_tensor: bool = False,
        device: Optional[torch.device] = None,
        normalize_embeddings: bool = False,
        **tokenizer_kwargs,
    ) -> Union[List[torch.Tensor], np.ndarray, torch.Tensor]:
        """
        Computes sentence embeddings
         Args:
             sentences(`str` or `List[str]`):
                 Sentence or sentences to be encoded
             batch_size(`int`, *optional*, defaults to 32):
                 Batch size for the computation
             show_progress_bar(`bool`, *optional*, defaults to None):
                 Show a progress bar when encoding sentences.
                 If set to None, progress bar is only shown when
                 `logger.level == logging.INFO` or `logger.level == logging.DEBUG`.
             convert_to_numpy(`bool`, *optional*, defaults to True):
                 If true, the output is a list of numpy vectors.
                 Else, it is a list of pytorch tensors.
             convert_to_tensor(`bool`, *optional*, defaults to False):
                 If true, you get one large tensor as return.
                 Overwrites any setting from convert_to_numpy
             device(`torch.device`, *optional*, defaults to None):
                 Which torch.device to use for the computation
             normalize_embeddings(`bool`, *optional*, defaults to False):
                 If set to true, returned vectors will have length 1. In that case,
                 the faster dot-product (util.dot_score) instead of cosine similarity
                 can be used.
             tokenizer_kwargs(`Dict[str, Any]`, *optional*, defaults to {}):
                 Keyword arguments for the tokenizer
         Returns:
             By default, a list of tensors is returned.
             If convert_to_tensor, a stacked tensor is returned.
             If convert_to_numpy, a numpy matrix is returned.
        """
        is_training = self.training
        self.eval()
        all_embeddings = []

        self.tokenizer = self.get_tokenizer()

        if show_progress_bar is None:
            show_progress_bar = (
                logger.getEffectiveLevel() == logging.INFO
                or logger.getEffectiveLevel() == logging.DEBUG
            )

        if convert_to_tensor:
            convert_to_numpy = False

        input_was_string = False
        if isinstance(sentences, str) or not hasattr(sentences, '__len__'):
            sentences = [sentences]
            input_was_string = True

        if device is not None:
            self.to(device)

        permutation = np.argsort([-len(i) for i in sentences])
        inverse_permutation = np.argsort(permutation)
        sentences = [sentences[idx] for idx in permutation]

        tokenizer_kwargs['padding'] = tokenizer_kwargs.get('padding', True)
        tokenizer_kwargs['max_length'] = tokenizer_kwargs.get('max_length', 512)
        tokenizer_kwargs['truncation'] = tokenizer_kwargs.get('truncation', True)

        if has_tqdm:
            range_iter = trange(
                0,
                len(sentences),
                batch_size,
                desc='Encoding',
                disable=not show_progress_bar,
            )
        else:
            range_iter = range(0, len(sentences), batch_size)

        for i in range_iter:
            encoded_input = self.tokenizer(
                sentences[i : i + batch_size],
                return_tensors='pt',
                **tokenizer_kwargs,
            ).to(self.device)

            embeddings = self.get_text_features(input_ids=encoded_input)
            if normalize_embeddings:
                embeddings = torch.nn.functional.normalize(embeddings, p=2, dim=1)
            if convert_to_numpy:
                embeddings = embeddings.cpu()
            all_embeddings.extend(embeddings)

        all_embeddings = [all_embeddings[idx] for idx in inverse_permutation]

        if convert_to_tensor:
            all_embeddings = torch.stack(all_embeddings)
        elif convert_to_numpy:
            all_embeddings = np.asarray([emb.to(torch.float32).numpy() for emb in all_embeddings])

        if input_was_string:
            all_embeddings = all_embeddings[0]

        self.train(is_training)
        return all_embeddings

    def decode_data_image(data_image_str):
        header, data = data_image_str.split(',', 1)
        image_data = base64.b64decode(data)
        return Image.open(BytesIO(image_data))

    @torch.inference_mode()
    def encode_image(
        self,
        images: Union[str, List[Union[str, "Image.Image"]]],
        batch_size: int = 32,
        show_progress_bar: Optional[bool] = None,
        convert_to_numpy: bool = True,
        convert_to_tensor: bool = False,
        device: Optional[torch.device] = None,
        normalize_embeddings: bool = False,
    ) -> Union[List[torch.Tensor], np.ndarray, torch.Tensor]:
        """
        Computes image embeddings.
    
        Args:
            images(`str` or `List[Union[str, Image.Image]]`):
                image paths, URLs, PIL images, or data:image/ strings to be encoded
            batch_size(`int`, *optional*, defaults to 32):
                Batch size for the computation
            show_progress_bar(`bool`, *optional*, defaults to None):
                Show a progress bar when encoding images.
                If set to None, progress bar is only shown when
                `logger.level == logging.INFO` or `logger.level == logging.DEBUG`.
            convert_to_numpy(`bool`, *optional*, defaults to True):
                If true, the output is a list of numpy vectors.
                Else, it is a list of pytorch tensors.
            convert_to_tensor(`bool`, *optional*, defaults to False):
                If true, you get one large tensor as return.
                Overwrites any setting from convert_to_numpy
            device(`torch.device`, *optional*, defaults to None):
                Which torch.device to use for the computation
            normalize_embeddings(`bool`, *optional*, defaults to False):
                If set to true, returned vectors will have length 1. In that case,
                the faster dot-product (util.dot_score) instead of cosine similarity
                can be used.
        Returns:
            By default, a list of tensors is returned.
            If convert_to_tensor, a stacked tensor is returned.
            If convert_to_numpy, a numpy matrix is returned.
        """
        
        is_training = self.training
        self.eval()
    
        self.preprocess = self.get_preprocess()
        all_embeddings = []
    
        if show_progress_bar is None:
            show_progress_bar = (
                logger.getEffectiveLevel() == logging.INFO
                or logger.getEffectiveLevel() == logging.DEBUG
            )
    
        if convert_to_tensor:
            convert_to_numpy = False
    
        input_was_single_img = False
        if isinstance(images, str) or not hasattr(images, '__len__'):
            images = [images]
            input_was_single_img = True
    
        if device is not None:
            self.to(device)
    
        permutation = np.argsort([-len(str(i)) for i in images])
        inverse_permutation = np.argsort(permutation)
        images = [images[idx] for idx in permutation]
    
        if has_tqdm:
            range_iter = trange(
                0,
                len(images),
                batch_size,
                desc='Encoding',
                disable=not show_progress_bar,
            )
        else:
            range_iter = range(0, len(images), batch_size)

        from PIL import Image
    
        for i in range_iter:
            batch_images = images[i:i+batch_size]
            processed_inputs = []
    
            for img in batch_images:
                if isinstance(img, str):
                    if img.startswith('http'):
                        response = requests.get(img)
                        image = Image.open(BytesIO(response.content)).convert('RGB')
                    elif img.startswith('data:image/'):
                        image = decode_data_image(img).convert('RGB')
                    else:
                        image = Image.open(img).convert('RGB')
                elif isinstance(img, Image.Image):
                    image = img.convert('RGB')
                else:
                    raise ValueError("Unsupported image format")
    
                processed_inputs.append(image)
    
            processed_inputs = self.preprocess(processed_inputs)
            processed_inputs = processed_inputs.to(self.device)
            embeddings = self.get_image_features(processed_inputs)
            
            if normalize_embeddings:
                embeddings = torch.nn.functional.normalize(embeddings, p=2, dim=1)
            if convert_to_numpy:
                embeddings = embeddings.cpu()
            all_embeddings.extend(embeddings)
    
        all_embeddings = [all_embeddings[idx] for idx in inverse_permutation]
    
        if convert_to_tensor:
            all_embeddings = torch.stack(all_embeddings)
        elif convert_to_numpy:
            all_embeddings = np.asarray([emb.to(torch.float32).numpy() for emb in all_embeddings])
    
        if input_was_single_img:
            all_embeddings = all_embeddings[0]
    
        self.train(is_training)
        return all_embeddings

    def forward(
        self,
        input_ids: Union[None, torch.Tensor, BatchEncoding] = None,
        pixel_values: Union[None, torch.FloatTensor, BatchFeature] = None,
        return_dict: Optional[bool] = None,
        return_loss: Optional[bool] = None,
        *_,
        **__,
    ) -> Union[Tuple[Optional[torch.FloatTensor], ...], CLIPOutput]:
        return_dict = (
            return_dict if return_dict is not None else self.config.use_return_dict
        )
        image_embeds = self.get_image_features(pixel_values=pixel_values)
        text_embeds = self.get_text_features(input_ids=input_ids)

        # normalized features
        image_embeds = image_embeds / image_embeds.norm(p=2, dim=-1, keepdim=True)
        text_embeds = text_embeds / text_embeds.norm(p=2, dim=-1, keepdim=True)

        # cosine similarity as logits
        logit_scale = self.logit_scale.exp()
        logits_per_text = torch.matmul(text_embeds, image_embeds.t()) * logit_scale
        logits_per_image = logits_per_text.t()

        loss = None
        if return_loss:
            loss = clip_loss(logits_per_text)

        if not return_dict:
            output = (
                logits_per_image,
                logits_per_text,
                text_embeds,
                image_embeds,
                None,
                None,
            )
            return ((loss,) + output) if loss is not None else output

        return CLIPOutput(
            loss=loss,
            logits_per_image=logits_per_image,
            logits_per_text=logits_per_text,
            text_embeds=text_embeds,
            image_embeds=image_embeds,
            text_model_output=None,
            vision_model_output=None,
        )