2809 lines
118 KiB
Python
2809 lines
118 KiB
Python
# These codes are copied from modelscope revision c58451baead80d83281f063d12fb377fad415257
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# Copyright 2018 The Google AI Language Team Authors and The HuggingFace Inc. team.
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# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""PyTorch MPLUG model. """
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import math
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import os
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from typing import Tuple
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import torch
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import torch.nn.functional as F
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import torch.utils.checkpoint
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import transformers
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from torch import Tensor, device, nn
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from torch.nn import CrossEntropyLoss
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from transformers import BertConfig, BertTokenizer
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from transformers.activations import ACT2FN
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from transformers.file_utils import (add_code_sample_docstrings,
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add_start_docstrings,
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add_start_docstrings_to_model_forward,
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replace_return_docstrings)
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from transformers.modeling_outputs import (
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BaseModelOutputWithPastAndCrossAttentions,
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BaseModelOutputWithPoolingAndCrossAttentions,
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CausalLMOutputWithCrossAttentions)
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from transformers.modeling_utils import (PreTrainedModel,
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apply_chunking_to_forward,
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find_pruneable_heads_and_indices,
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prune_linear_layer)
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from transformers.utils import logging
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from modelscope.models.multi_modal.mplug.configuration_mplug import (
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HiTeAConfig, MPlugConfig)
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from modelscope.models.multi_modal.mplug.mvit import MViTv2, MViTv2_Base_config
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from modelscope.models.multi_modal.mplug.predictor import TextGenerator
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from modelscope.utils.constant import ModelFile
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transformers.logging.set_verbosity_error()
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logger = logging.get_logger()
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CONFIG_NAME = 'config.yaml'
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_CONFIG_FOR_DOC = 'BertConfig'
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_TOKENIZER_FOR_DOC = 'BertTokenizer'
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def load_tf_weights_in_bert(model, config, tf_checkpoint_path):
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"""Load tf checkpoints in a pytorch model."""
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try:
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import re
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import numpy as np
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import tensorflow as tf
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except ImportError:
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logger.error(
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'Loading a TensorFlow model in PyTorch, requires TensorFlow to be installed. Please see '
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'https://www.tensorflow.org/install/ for installation instructions.'
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)
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raise
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tf_path = os.path.abspath(tf_checkpoint_path)
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logger.info('Converting TensorFlow checkpoint from {}'.format(tf_path))
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# Load weights from TF model
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init_vars = tf.train.list_variables(tf_path)
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names = []
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arrays = []
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for name, shape in init_vars:
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logger.info('Loading TF weight {} with shape {}'.format(name, shape))
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array = tf.train.load_variable(tf_path, name)
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names.append(name)
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arrays.append(array)
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for name, array in zip(names, arrays):
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name = name.split('/')
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# adam_v and adam_m are variables used in AdamWeightDecayOptimizer to calculated m and v
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# which are not required for using pretrained model
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if any(n in [
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'adam_v', 'adam_m', 'AdamWeightDecayOptimizer',
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'AdamWeightDecayOptimizer_1', 'global_step'
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] for n in name):
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logger.info('Skipping {}'.format('/'.join(name)))
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continue
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pointer = model
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for m_name in name:
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if re.fullmatch(r'[A-Za-z]+_\d+', m_name):
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scope_names = re.split(r'_(\d+)', m_name)
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else:
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scope_names = [m_name]
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if scope_names[0] == 'kernel' or scope_names[0] == 'gamma':
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pointer = getattr(pointer, 'weight')
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elif scope_names[0] == 'output_bias' or scope_names[0] == 'beta':
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pointer = getattr(pointer, 'bias')
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elif scope_names[0] == 'output_weights':
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pointer = getattr(pointer, 'weight')
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elif scope_names[0] == 'squad':
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pointer = getattr(pointer, 'classifier')
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else:
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try:
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pointer = getattr(pointer, scope_names[0])
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except AttributeError:
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logger.info('Skipping {}'.format('/'.join(name)))
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continue
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if len(scope_names) >= 2:
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num = int(scope_names[1])
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pointer = pointer[num]
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if m_name[-11:] == '_embeddings':
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pointer = getattr(pointer, 'weight')
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elif m_name == 'kernel':
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array = np.transpose(array)
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try:
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assert (
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pointer.shape == array.shape
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), f'Pointer shape {pointer.shape} and array shape {array.shape} mismatched'
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except AssertionError as e:
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e.args += (pointer.shape, array.shape)
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raise
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logger.info('Initialize PyTorch weight {}'.format(name))
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pointer.data = torch.from_numpy(array)
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return model
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def clamp_inf(tensor):
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if tensor.dtype == torch.float16 and torch.isinf(tensor).any():
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clamp_value = torch.finfo(tensor.dtype).max - 1000
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tensor = torch.clamp(tensor, min=-clamp_value, max=clamp_value)
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return tensor
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class BertEmbeddings(nn.Module):
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"""Construct the embeddings from word, position and token_type embeddings."""
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def __init__(self, config):
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super().__init__()
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self.word_embeddings = nn.Embedding(
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config.vocab_size,
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config.hidden_size,
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padding_idx=config.pad_token_id)
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self.position_embeddings = nn.Embedding(config.max_position_embeddings,
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config.hidden_size)
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self.token_type_embeddings = nn.Embedding(config.type_vocab_size,
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config.hidden_size)
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# self.LayerNorm is not snake-cased to stick with TensorFlow model variable name and be able to load
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# any TensorFlow checkpoint file
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self.LayerNorm = nn.LayerNorm(
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config.hidden_size, eps=config.layer_norm_eps)
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self.dropout = nn.Dropout(config.hidden_dropout_prob)
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# position_ids (1, len position emb) is contiguous in memory and exported when serialized
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self.register_buffer(
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'position_ids',
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torch.arange(config.max_position_embeddings).expand((1, -1)))
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self.position_embedding_type = getattr(config,
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'position_embedding_type',
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'absolute')
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self.config = config
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def forward(self,
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input_ids=None,
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token_type_ids=None,
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position_ids=None,
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inputs_embeds=None,
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past_key_values_length=0):
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if input_ids is not None:
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input_shape = input_ids.size()
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else:
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input_shape = inputs_embeds.size()[:-1]
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seq_length = input_shape[1]
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if position_ids is None:
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position_ids = self.position_ids[:,
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past_key_values_length:seq_length
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+ past_key_values_length]
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if token_type_ids is None:
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token_type_ids = torch.zeros(
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input_shape, dtype=torch.long, device=self.position_ids.device)
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if inputs_embeds is None:
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inputs_embeds = self.word_embeddings(input_ids)
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token_type_embeddings = self.token_type_embeddings(token_type_ids)
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embeddings = inputs_embeds + token_type_embeddings
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if self.position_embedding_type == 'absolute':
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position_embeddings = self.position_embeddings(position_ids)
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embeddings += position_embeddings
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embeddings = self.LayerNorm(embeddings)
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embeddings = self.dropout(embeddings)
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return embeddings
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class BertSelfAttention(nn.Module):
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def __init__(self, config, is_cross_attention):
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super().__init__()
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self.config = config
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if config.hidden_size % config.num_attention_heads != 0 and not hasattr(
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config, 'embedding_size'):
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raise ValueError(
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'The hidden size (%d) is not a multiple of the number of attention '
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'heads (%d)' %
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(config.hidden_size, config.num_attention_heads))
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self.num_attention_heads = config.num_attention_heads
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self.attention_head_size = int(config.hidden_size
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/ config.num_attention_heads)
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self.all_head_size = self.num_attention_heads * self.attention_head_size
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self.query = nn.Linear(config.hidden_size, self.all_head_size)
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if is_cross_attention:
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self.key = nn.Linear(config.encoder_width, self.all_head_size)
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self.value = nn.Linear(config.encoder_width, self.all_head_size)
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else:
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self.key = nn.Linear(config.hidden_size, self.all_head_size)
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self.value = nn.Linear(config.hidden_size, self.all_head_size)
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self.dropout = nn.Dropout(config.attention_probs_dropout_prob)
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self.position_embedding_type = getattr(config,
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'position_embedding_type',
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'absolute')
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if self.position_embedding_type == 'relative_key' or self.position_embedding_type == 'relative_key_query':
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self.max_position_embeddings = config.max_position_embeddings
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self.distance_embedding = nn.Embedding(
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2 * config.max_position_embeddings - 1,
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self.attention_head_size)
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self.save_attention = False
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def save_attn_gradients(self, attn_gradients):
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self.attn_gradients = attn_gradients
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def get_attn_gradients(self):
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return self.attn_gradients
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def save_attention_map(self, attention_map):
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self.attention_map = attention_map
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def get_attention_map(self):
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return self.attention_map
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def transpose_for_scores(self, x):
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new_x_shape = x.size()[:-1] + (self.num_attention_heads,
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self.attention_head_size)
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x = x.view(*new_x_shape)
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return x.permute(0, 2, 1, 3)
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def forward(
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self,
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hidden_states,
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attention_mask=None,
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head_mask=None,
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encoder_hidden_states=None,
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encoder_attention_mask=None,
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past_key_value=None,
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output_attentions=False,
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):
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mixed_query_layer = self.query(hidden_states)
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# If this is instantiated as a cross-attention module, the keys
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# and values come from an encoder; the attention mask needs to be
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# such that the encoder's padding tokens are not attended to.
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is_cross_attention = encoder_hidden_states is not None
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if is_cross_attention:
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key_layer = self.transpose_for_scores(
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self.key(encoder_hidden_states))
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value_layer = self.transpose_for_scores(
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self.value(encoder_hidden_states))
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attention_mask = encoder_attention_mask
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elif past_key_value is not None:
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key_layer = self.transpose_for_scores(self.key(hidden_states))
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value_layer = self.transpose_for_scores(self.value(hidden_states))
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key_layer = torch.cat([past_key_value[0], key_layer], dim=2)
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value_layer = torch.cat([past_key_value[1], value_layer], dim=2)
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else:
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key_layer = self.transpose_for_scores(self.key(hidden_states))
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value_layer = self.transpose_for_scores(self.value(hidden_states))
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query_layer = self.transpose_for_scores(mixed_query_layer)
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past_key_value = (key_layer, value_layer)
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# Take the dot product between "query" and "key" to get the raw attention scores.
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attention_scores = torch.matmul(query_layer,
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key_layer.transpose(-1, -2))
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attention_scores = clamp_inf(attention_scores)
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if self.position_embedding_type == 'relative_key' or self.position_embedding_type == 'relative_key_query':
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seq_length = hidden_states.size()[1]
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position_ids_l = torch.arange(
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seq_length, dtype=torch.long,
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device=hidden_states.device).view(-1, 1)
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position_ids_r = torch.arange(
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seq_length, dtype=torch.long,
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device=hidden_states.device).view(1, -1)
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distance = position_ids_l - position_ids_r
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positional_embedding = self.distance_embedding(
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distance + self.max_position_embeddings - 1)
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positional_embedding = positional_embedding.to(
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dtype=query_layer.dtype) # fp16 compatibility
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if self.position_embedding_type == 'relative_key':
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relative_position_scores = torch.einsum(
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'bhld,lrd->bhlr', query_layer, positional_embedding)
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attention_scores = attention_scores + relative_position_scores
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elif self.position_embedding_type == 'relative_key_query':
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relative_position_scores_query = torch.einsum(
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'bhld,lrd->bhlr', query_layer, positional_embedding)
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relative_position_scores_key = torch.einsum(
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'bhrd,lrd->bhlr', key_layer, positional_embedding)
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attention_scores = attention_scores + relative_position_scores_query + relative_position_scores_key
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attention_scores = attention_scores / math.sqrt(
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self.attention_head_size)
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if attention_mask is not None:
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# Apply the attention mask is (precomputed for all layers in BertModel forward() function)
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attention_scores = attention_scores + attention_mask
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# Normalize the attention scores to probabilities.
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attention_probs = nn.Softmax(dim=-1)(attention_scores)
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if is_cross_attention and self.save_attention:
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self.save_attention_map(attention_probs)
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attention_probs.register_hook(self.save_attn_gradients)
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# This is actually dropping out entire tokens to attend to, which might
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# seem a bit unusual, but is taken from the original Transformer paper.
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attention_probs_dropped = self.dropout(attention_probs)
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# Mask heads if we want to
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if head_mask is not None:
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attention_probs_dropped = attention_probs_dropped * head_mask
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context_layer = torch.matmul(attention_probs_dropped, value_layer)
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context_layer = context_layer.permute(0, 2, 1, 3).contiguous()
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new_context_layer_shape = context_layer.size()[:-2] + (
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self.all_head_size, )
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context_layer = context_layer.view(*new_context_layer_shape)
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outputs = (context_layer,
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attention_probs) if output_attentions else (context_layer, )
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outputs = outputs + (past_key_value, )
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return outputs
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class BertSelfOutput(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.hidden_size, config.hidden_size)
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self.LayerNorm = nn.LayerNorm(
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config.hidden_size, eps=config.layer_norm_eps)
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self.dropout = nn.Dropout(config.hidden_dropout_prob)
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def forward(self, hidden_states, input_tensor):
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hidden_states = self.dense(hidden_states)
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hidden_states = self.dropout(hidden_states)
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hidden_states = self.LayerNorm(hidden_states + input_tensor)
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return hidden_states
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class BertAttention(nn.Module):
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def __init__(self, config, is_cross_attention=False):
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super().__init__()
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self.self = BertSelfAttention(config, is_cross_attention)
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self.output = BertSelfOutput(config)
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self.pruned_heads = set()
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def prune_heads(self, heads):
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if len(heads) == 0:
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return
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heads, index = find_pruneable_heads_and_indices(
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heads, self.self.num_attention_heads,
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self.self.attention_head_size, self.pruned_heads)
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# Prune linear layers
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self.self.query = prune_linear_layer(self.self.query, index)
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self.self.key = prune_linear_layer(self.self.key, index)
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self.self.value = prune_linear_layer(self.self.value, index)
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self.output.dense = prune_linear_layer(self.output.dense, index, dim=1)
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# Update hyper params and store pruned heads
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self.self.num_attention_heads = self.self.num_attention_heads - len(
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heads)
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self.self.all_head_size = self.self.attention_head_size * self.self.num_attention_heads
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self.pruned_heads = self.pruned_heads.union(heads)
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def forward(
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self,
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hidden_states,
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attention_mask=None,
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head_mask=None,
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encoder_hidden_states=None,
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encoder_attention_mask=None,
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past_key_value=None,
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output_attentions=False,
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):
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self_outputs = self.self(
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hidden_states,
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attention_mask,
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head_mask,
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encoder_hidden_states,
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encoder_attention_mask,
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past_key_value,
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output_attentions,
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)
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attention_output = self.output(self_outputs[0], hidden_states)
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outputs = (attention_output,
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) + self_outputs[1:] # add attentions if we output them
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return outputs
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|
|
|
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class BertIntermediate(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.hidden_size, config.intermediate_size)
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if isinstance(config.hidden_act, str):
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self.intermediate_act_fn = ACT2FN[config.hidden_act]
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else:
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self.intermediate_act_fn = config.hidden_act
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def forward(self, hidden_states):
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hidden_states = self.dense(hidden_states)
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hidden_states = self.intermediate_act_fn(hidden_states)
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return hidden_states
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|
|
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class BertOutput(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.intermediate_size, config.hidden_size)
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self.LayerNorm = nn.LayerNorm(
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config.hidden_size, eps=config.layer_norm_eps)
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self.dropout = nn.Dropout(config.hidden_dropout_prob)
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def forward(self, hidden_states, input_tensor):
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hidden_states = self.dense(hidden_states)
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hidden_states = clamp_inf(hidden_states)
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hidden_states = self.dropout(hidden_states)
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hidden_states = clamp_inf(hidden_states)
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hidden_states = self.LayerNorm(hidden_states + input_tensor)
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return hidden_states
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|
|
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class FusionLayer(nn.Module):
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|
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def __init__(self, config, layer_num):
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super().__init__()
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self.config = config
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self.stride_layer = getattr(self.config, 'stride_layer', 100)
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self.chunk_size_feed_forward = config.chunk_size_feed_forward
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self.seq_len_dim = 1
|
|
self.attention = BertAttention(config)
|
|
|
|
self.crossattention = BertAttention(config, is_cross_attention=True)
|
|
self.intermediate = BertIntermediate(config)
|
|
self.output = BertOutput(config)
|
|
|
|
def forward(
|
|
self,
|
|
hidden_states,
|
|
attention_mask=None,
|
|
head_mask=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
layer_nums=None,
|
|
past_key_value=None,
|
|
output_attentions=False,
|
|
):
|
|
# decoder uni-directional self-attention cached key/values tuple is at positions 1,2
|
|
self_attn_past_key_value = past_key_value[:
|
|
2] if past_key_value is not None else None
|
|
if layer_nums == 0 or layer_nums % self.stride_layer != 0:
|
|
self_attention_outputs = self.attention(
|
|
hidden_states,
|
|
attention_mask,
|
|
head_mask,
|
|
output_attentions=output_attentions,
|
|
past_key_value=self_attn_past_key_value,
|
|
)
|
|
attention_output = self_attention_outputs[0]
|
|
|
|
outputs = self_attention_outputs[1:-1]
|
|
present_key_value = self_attention_outputs[-1]
|
|
assert encoder_hidden_states is not None, 'encoder_hidden_states must be given for cross-attention layers'
|
|
|
|
cross_attention_outputs = self.crossattention(
|
|
attention_output,
|
|
attention_mask,
|
|
head_mask,
|
|
encoder_hidden_states,
|
|
encoder_attention_mask,
|
|
output_attentions=output_attentions,
|
|
)
|
|
attention_output = cross_attention_outputs[0]
|
|
outputs = outputs + cross_attention_outputs[
|
|
1:-1] # add cross attentions if we output attention weights
|
|
elif layer_nums != 0 and layer_nums % self.stride_layer == 0:
|
|
self_attention_outputs = self.attention(
|
|
torch.cat([encoder_hidden_states, hidden_states], 1),
|
|
torch.cat([encoder_attention_mask, attention_mask], 3),
|
|
head_mask,
|
|
output_attentions=output_attentions,
|
|
past_key_value=self_attn_past_key_value,
|
|
)
|
|
attention_output = self_attention_outputs[0]
|
|
|
|
outputs = self_attention_outputs[1:-1]
|
|
present_key_value = self_attention_outputs[-1]
|
|
layer_output = apply_chunking_to_forward(self.feed_forward_chunk,
|
|
self.chunk_size_feed_forward,
|
|
self.seq_len_dim,
|
|
attention_output)
|
|
outputs = (layer_output, ) + outputs
|
|
|
|
outputs = outputs + (present_key_value[0], present_key_value[1])
|
|
|
|
return outputs
|
|
|
|
def feed_forward_chunk(self, attention_output):
|
|
intermediate_output = self.intermediate(attention_output)
|
|
layer_output = self.output(intermediate_output, attention_output)
|
|
return layer_output
|
|
|
|
|
|
class BertLayer(nn.Module):
|
|
|
|
def __init__(self, config, layer_num):
|
|
super().__init__()
|
|
self.config = config
|
|
self.chunk_size_feed_forward = config.chunk_size_feed_forward
|
|
self.seq_len_dim = 1
|
|
self.attention = BertAttention(config)
|
|
|
|
self.has_cross_attention = getattr(self.config, 'add_cross_attention',
|
|
False)
|
|
if self.has_cross_attention:
|
|
self.crossattention = BertAttention(
|
|
config, is_cross_attention=True)
|
|
self.intermediate = BertIntermediate(config)
|
|
self.output = BertOutput(config)
|
|
|
|
def forward(
|
|
self,
|
|
hidden_states,
|
|
attention_mask=None,
|
|
head_mask=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
past_key_value=None,
|
|
output_attentions=False,
|
|
):
|
|
# decoder uni-directional self-attention cached key/values tuple is at positions 1,2
|
|
self_attn_past_key_value = past_key_value[:
|
|
2] if past_key_value is not None else None
|
|
self_attention_outputs = self.attention(
|
|
hidden_states,
|
|
attention_mask,
|
|
head_mask,
|
|
output_attentions=output_attentions,
|
|
past_key_value=self_attn_past_key_value,
|
|
)
|
|
attention_output = self_attention_outputs[0]
|
|
|
|
outputs = self_attention_outputs[1:-1]
|
|
present_key_value = self_attention_outputs[-1]
|
|
|
|
if self.has_cross_attention:
|
|
assert encoder_hidden_states is not None, 'encoder_hidden_states must be given for cross-attention layers'
|
|
|
|
if type(encoder_hidden_states) == list:
|
|
cross_attention_outputs = self.crossattention(
|
|
attention_output,
|
|
attention_mask,
|
|
head_mask,
|
|
encoder_hidden_states[(self.layer_num
|
|
- self.config.fusion_layer)
|
|
% len(encoder_hidden_states)],
|
|
encoder_attention_mask[(self.layer_num
|
|
- self.config.fusion_layer)
|
|
% len(encoder_hidden_states)],
|
|
output_attentions=output_attentions,
|
|
)
|
|
attention_output = cross_attention_outputs[0]
|
|
outputs = outputs + cross_attention_outputs[1:-1]
|
|
|
|
else:
|
|
cross_attention_outputs = self.crossattention(
|
|
attention_output,
|
|
attention_mask,
|
|
head_mask,
|
|
encoder_hidden_states,
|
|
encoder_attention_mask,
|
|
output_attentions=output_attentions,
|
|
)
|
|
attention_output = cross_attention_outputs[0]
|
|
outputs = outputs + cross_attention_outputs[
|
|
1:
|
|
-1] # add cross attentions if we output attention weights
|
|
layer_output = apply_chunking_to_forward(self.feed_forward_chunk,
|
|
self.chunk_size_feed_forward,
|
|
self.seq_len_dim,
|
|
attention_output)
|
|
outputs = (layer_output, ) + outputs
|
|
|
|
outputs = outputs + (present_key_value[0], present_key_value[1])
|
|
|
|
return outputs
|
|
|
|
def feed_forward_chunk(self, attention_output):
|
|
intermediate_output = self.intermediate(attention_output)
|
|
layer_output = self.output(intermediate_output, attention_output)
|
|
return layer_output
|
|
|
|
|
|
class FusionEncoder(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.config = config
|
|
self.layer = nn.ModuleList(
|
|
[FusionLayer(config, i) for i in range(config.num_hidden_layers)])
|
|
self.start_layer = max(0,
|
|
config.num_hidden_layers - config.fusion_layers)
|
|
|
|
def forward(self,
|
|
hidden_states,
|
|
attention_mask=None,
|
|
head_mask=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
past_key_values=None,
|
|
use_cache=None,
|
|
output_attentions=False,
|
|
output_hidden_states=False,
|
|
return_dict=True):
|
|
all_hidden_states = () if output_hidden_states else None
|
|
all_self_attentions = () if output_attentions else None
|
|
|
|
next_decoder_cache = () if use_cache else None
|
|
|
|
self.stride_layer = getattr(self.config, 'stride_layer', 100)
|
|
image_length = encoder_hidden_states.shape[1]
|
|
text_length = hidden_states.shape[1]
|
|
|
|
for i in range(self.start_layer, len(self.layer)):
|
|
layer_module = self.layer[i]
|
|
if output_hidden_states:
|
|
all_hidden_states = all_hidden_states + (hidden_states, )
|
|
|
|
layer_head_mask = head_mask[i] if head_mask is not None else None
|
|
past_key_value = past_key_values[
|
|
i] if past_key_values is not None else None
|
|
|
|
if getattr(self.config, 'gradient_checkpointing',
|
|
False) and self.training:
|
|
if use_cache:
|
|
logger.warning(
|
|
'`use_cache=True` is incompatible with `config.gradient_checkpointing=True`. Setting '
|
|
'`use_cache=False`...')
|
|
use_cache = False
|
|
|
|
def create_custom_forward(module):
|
|
|
|
def custom_forward(*inputs):
|
|
return tuple(
|
|
module(*inputs, past_key_value, output_attentions))
|
|
|
|
return custom_forward
|
|
|
|
layer_outputs = torch.utils.checkpoint.checkpoint(
|
|
create_custom_forward(layer_module),
|
|
hidden_states,
|
|
attention_mask,
|
|
layer_head_mask,
|
|
encoder_hidden_states,
|
|
encoder_attention_mask,
|
|
i - self.start_layer,
|
|
)
|
|
else:
|
|
layer_outputs = layer_module(
|
|
hidden_states,
|
|
attention_mask,
|
|
layer_head_mask,
|
|
encoder_hidden_states,
|
|
encoder_attention_mask,
|
|
i - self.start_layer,
|
|
past_key_value,
|
|
output_attentions,
|
|
)
|
|
|
|
hidden_states = layer_outputs[0]
|
|
if use_cache:
|
|
next_decoder_cache += (layer_outputs[-1], )
|
|
if output_attentions:
|
|
all_self_attentions = all_self_attentions + (
|
|
layer_outputs[1], )
|
|
if hidden_states.shape[1] == (image_length + text_length):
|
|
encoder_hidden_states_new, hidden_states = torch.split(
|
|
hidden_states, (image_length, text_length), 1)
|
|
encoder_hidden_states += encoder_hidden_states_new
|
|
|
|
if output_hidden_states:
|
|
all_hidden_states = all_hidden_states + (hidden_states, )
|
|
return [encoder_hidden_states, hidden_states]
|
|
|
|
|
|
class BertEncoder(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.config = config
|
|
self.layer = nn.ModuleList(
|
|
[BertLayer(config, i) for i in range(config.num_hidden_layers)])
|
|
|
|
def forward(self,
|
|
hidden_states,
|
|
attention_mask=None,
|
|
head_mask=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
past_key_values=None,
|
|
use_cache=None,
|
|
output_attentions=False,
|
|
output_hidden_states=False,
|
|
return_dict=True):
|
|
all_hidden_states = () if output_hidden_states else None
|
|
all_self_attentions = () if output_attentions else None
|
|
all_cross_attentions = (
|
|
) if output_attentions and self.config.add_cross_attention else None
|
|
|
|
next_decoder_cache = () if use_cache else None
|
|
|
|
for i in range(len(self.layer)):
|
|
layer_module = self.layer[i]
|
|
if output_hidden_states:
|
|
all_hidden_states = all_hidden_states + (hidden_states, )
|
|
|
|
layer_head_mask = head_mask[i] if head_mask is not None else None
|
|
past_key_value = past_key_values[
|
|
i] if past_key_values is not None else None
|
|
|
|
if getattr(self.config, 'gradient_checkpointing',
|
|
False) and self.training:
|
|
if use_cache:
|
|
logger.warning(
|
|
'`use_cache=True` is incompatible with `config.gradient_checkpointing=True`. Setting '
|
|
'`use_cache=False`...')
|
|
use_cache = False
|
|
|
|
def create_custom_forward(module):
|
|
|
|
def custom_forward(*inputs):
|
|
return tuple(
|
|
module(*inputs, past_key_value, output_attentions))
|
|
|
|
return custom_forward
|
|
|
|
layer_outputs = torch.utils.checkpoint.checkpoint(
|
|
create_custom_forward(layer_module), hidden_states,
|
|
attention_mask, layer_head_mask, encoder_hidden_states,
|
|
encoder_attention_mask)
|
|
else:
|
|
layer_outputs = layer_module(
|
|
hidden_states,
|
|
attention_mask,
|
|
layer_head_mask,
|
|
encoder_hidden_states,
|
|
encoder_attention_mask,
|
|
past_key_value,
|
|
output_attentions,
|
|
)
|
|
|
|
hidden_states = layer_outputs[0]
|
|
if use_cache:
|
|
next_decoder_cache += (layer_outputs[-1], )
|
|
if output_attentions:
|
|
all_self_attentions = all_self_attentions + (
|
|
layer_outputs[1], )
|
|
if output_hidden_states:
|
|
all_hidden_states = all_hidden_states + (hidden_states, )
|
|
|
|
if not return_dict:
|
|
return tuple(v for v in [
|
|
hidden_states,
|
|
next_decoder_cache,
|
|
all_hidden_states,
|
|
all_self_attentions,
|
|
all_cross_attentions,
|
|
] if v is not None)
|
|
return BaseModelOutputWithPastAndCrossAttentions(
|
|
last_hidden_state=hidden_states,
|
|
past_key_values=next_decoder_cache,
|
|
hidden_states=all_hidden_states,
|
|
attentions=all_self_attentions,
|
|
cross_attentions=all_cross_attentions,
|
|
)
|
|
|
|
|
|
class BertPooler(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.dense = nn.Linear(config.hidden_size, config.hidden_size)
|
|
self.activation = nn.Tanh()
|
|
|
|
def forward(self, hidden_states):
|
|
# We "pool" the model by simply taking the hidden state corresponding
|
|
# to the first token.
|
|
first_token_tensor = hidden_states[:, 0]
|
|
pooled_output = self.dense(first_token_tensor)
|
|
pooled_output = self.activation(pooled_output)
|
|
return pooled_output
|
|
|
|
|
|
class BertPredictionHeadTransform(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.dense = nn.Linear(config.hidden_size, config.hidden_size)
|
|
if isinstance(config.hidden_act, str):
|
|
self.transform_act_fn = ACT2FN[config.hidden_act]
|
|
else:
|
|
self.transform_act_fn = config.hidden_act
|
|
self.LayerNorm = nn.LayerNorm(
|
|
config.hidden_size, eps=config.layer_norm_eps)
|
|
|
|
def forward(self, hidden_states):
|
|
hidden_states = self.dense(hidden_states)
|
|
hidden_states = self.transform_act_fn(hidden_states)
|
|
hidden_states = self.LayerNorm(hidden_states)
|
|
return hidden_states
|
|
|
|
|
|
class BertLMPredictionHead(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.transform = BertPredictionHeadTransform(config)
|
|
|
|
# The output weights are the same as the input embeddings, but there is
|
|
# an output-only bias for each token.
|
|
self.decoder = nn.Linear(
|
|
config.hidden_size, config.vocab_size, bias=False)
|
|
|
|
self.bias = nn.Parameter(torch.zeros(config.vocab_size))
|
|
|
|
# Need a link between the two variables so that the bias is correctly resized with `resize_token_embeddings`
|
|
self.decoder.bias = self.bias
|
|
|
|
def forward(self, hidden_states):
|
|
hidden_states = self.transform(hidden_states)
|
|
hidden_states = self.decoder(hidden_states)
|
|
return hidden_states
|
|
|
|
|
|
class BertOnlyMLMHead(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.predictions = BertLMPredictionHead(config)
|
|
|
|
def forward(self, sequence_output):
|
|
prediction_scores = self.predictions(sequence_output)
|
|
return prediction_scores
|
|
|
|
|
|
class BertOnlyNSPHead(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.seq_relationship = nn.Linear(config.hidden_size, 2)
|
|
|
|
def forward(self, pooled_output):
|
|
seq_relationship_score = self.seq_relationship(pooled_output)
|
|
return seq_relationship_score
|
|
|
|
|
|
class BertPreTrainingHeads(nn.Module):
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.predictions = BertLMPredictionHead(config)
|
|
self.seq_relationship = nn.Linear(config.hidden_size, 2)
|
|
|
|
def forward(self, sequence_output, pooled_output):
|
|
prediction_scores = self.predictions(sequence_output)
|
|
seq_relationship_score = self.seq_relationship(pooled_output)
|
|
return prediction_scores, seq_relationship_score
|
|
|
|
|
|
class BertPreTrainedModel(PreTrainedModel):
|
|
"""
|
|
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
|
|
models.
|
|
"""
|
|
|
|
config_class = BertConfig
|
|
load_tf_weights = load_tf_weights_in_bert
|
|
base_model_prefix = 'bert'
|
|
_keys_to_ignore_on_load_missing = [r'position_ids']
|
|
|
|
def _init_weights(self, module):
|
|
""" Initialize the weights """
|
|
if isinstance(module, (nn.Linear, nn.Embedding)):
|
|
# Slightly different from the TF version which uses truncated_normal for initialization
|
|
# cf https://github.com/pytorch/pytorch/pull/5617
|
|
module.weight.data.normal_(
|
|
mean=0.0, std=self.config.initializer_range)
|
|
elif 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_()
|
|
|
|
|
|
BERT_START_DOCSTRING = r"""
|
|
This model inherits from :class:`~transformers.PreTrainedModel`. Check the superclass documentation for the generic
|
|
methods the library implements for all its model (such as downloading or saving, resizing the input embeddings,
|
|
pruning heads etc.)
|
|
This model is also a PyTorch `torch.nn.Module <https://pytorch.org/docs/stable/nn.html#torch.nn.Module>`__
|
|
subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to
|
|
general usage and behavior.
|
|
Parameters:
|
|
config (:class:`~transformers.BertConfig`): Model configuration class with all the parameters of the model.
|
|
Initializing with a config file does not load the weights associated with the model, only the
|
|
configuration. Check out the :meth:`~transformers.PreTrainedModel.from_pretrained` method to load the model
|
|
weights.
|
|
"""
|
|
|
|
BERT_INPUTS_DOCSTRING = r"""
|
|
Args:
|
|
input_ids (:obj:`torch.LongTensor` of shape :obj:`({0})`):
|
|
Indices of input sequence tokens in the vocabulary.
|
|
Indices can be obtained using :class:`~transformers.BertTokenizer`. See
|
|
:meth:`transformers.PreTrainedTokenizer.encode` and :meth:`transformers.PreTrainedTokenizer.__call__` for
|
|
details.
|
|
`What are input IDs? <../glossary.html#input-ids>`__
|
|
attention_mask (:obj:`torch.FloatTensor` of shape :obj:`({0})`, `optional`):
|
|
Mask to avoid performing attention on padding token indices. Mask values selected in ``[0, 1]``:
|
|
- 1 for tokens that are **not masked**,
|
|
- 0 for tokens that are **masked**.
|
|
`What are attention masks? <../glossary.html#attention-mask>`__
|
|
token_type_ids (:obj:`torch.LongTensor` of shape :obj:`({0})`, `optional`):
|
|
Segment token indices to indicate first and second portions of the inputs. Indices are selected in ``[0,
|
|
1]``:
|
|
- 0 corresponds to a `sentence A` token,
|
|
- 1 corresponds to a `sentence B` token.
|
|
`What are token type IDs? <../glossary.html#token-type-ids>`_
|
|
position_ids (:obj:`torch.LongTensor` of shape :obj:`({0})`, `optional`):
|
|
Indices of positions of each input sequence tokens in the position embeddings. Selected in the range ``[0,
|
|
config.max_position_embeddings - 1]``.
|
|
`What are position IDs? <../glossary.html#position-ids>`_
|
|
head_mask (:obj:`torch.FloatTensor` of shape :obj:`(num_heads,)` or :obj:`(num_layers, num_heads)`, `optional`):
|
|
Mask to nullify selected heads of the self-attention modules. Mask values selected in ``[0, 1]``:
|
|
- 1 indicates the head is **not masked**,
|
|
- 0 indicates the head is **masked**.
|
|
inputs_embeds (:obj:`torch.FloatTensor` of shape :obj:`({0}, hidden_size)`, `optional`):
|
|
Optionally, instead of passing :obj:`input_ids` you can choose to directly pass an embedded representation.
|
|
This is useful if you want more control over how to convert :obj:`input_ids` indices into associated
|
|
vectors than the model's internal embedding lookup matrix.
|
|
output_attentions (:obj:`bool`, `optional`):
|
|
Whether or not to return the attentions tensors of all attention layers. See ``attentions`` under returned
|
|
tensors for more detail.
|
|
output_hidden_states (:obj:`bool`, `optional`):
|
|
Whether or not to return the hidden states of all layers. See ``hidden_states`` under returned tensors for
|
|
more detail.
|
|
return_dict (:obj:`bool`, `optional`):
|
|
Whether or not to return a :class:`~transformers.file_utils.ModelOutput` instead of a plain tuple.
|
|
"""
|
|
|
|
|
|
@add_start_docstrings(
|
|
'The bare Bert Model transformer outputting raw hidden-states without any specific head on top.',
|
|
BERT_START_DOCSTRING,
|
|
)
|
|
class BertModel(BertPreTrainedModel):
|
|
"""
|
|
The model can behave as an encoder (with only self-attention) as well as a decoder, in which case a layer of
|
|
cross-attention is added between the self-attention layers, following the architecture described in `Attention is
|
|
all you need <https://arxiv.org/abs/1706.03762>`__ by Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit,
|
|
Llion Jones, Aidan N. Gomez, Lukasz Kaiser and Illia Polosukhin.
|
|
argument and :obj:`add_cross_attention` set to :obj:`True`; an :obj:`encoder_hidden_states` is then expected as an
|
|
input to the forward pass.
|
|
"""
|
|
|
|
def __init__(self, config, add_pooling_layer=True):
|
|
super().__init__(config)
|
|
self.config = config
|
|
|
|
self.embeddings = BertEmbeddings(config)
|
|
|
|
self.encoder = BertEncoder(config)
|
|
|
|
self.pooler = BertPooler(config) if add_pooling_layer else None
|
|
|
|
self.init_weights()
|
|
|
|
def get_input_embeddings(self):
|
|
return self.embeddings.word_embeddings
|
|
|
|
def set_input_embeddings(self, value):
|
|
self.embeddings.word_embeddings = value
|
|
|
|
def _prune_heads(self, heads_to_prune):
|
|
"""
|
|
Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base
|
|
class PreTrainedModel
|
|
"""
|
|
for layer, heads in heads_to_prune.items():
|
|
self.encoder.layer[layer].attention.prune_heads(heads)
|
|
|
|
@add_start_docstrings_to_model_forward(
|
|
BERT_INPUTS_DOCSTRING.format('batch_size, sequence_length'))
|
|
@add_code_sample_docstrings(
|
|
processor_class=_TOKENIZER_FOR_DOC,
|
|
checkpoint='bert-base-uncased',
|
|
output_type=BaseModelOutputWithPoolingAndCrossAttentions,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
def get_extended_attention_mask(self, attention_mask: Tensor,
|
|
input_shape: Tuple[int], device: device,
|
|
is_decoder: bool) -> Tensor:
|
|
"""
|
|
Makes broadcastable attention and causal masks so that future and masked tokens are ignored.
|
|
|
|
Arguments:
|
|
attention_mask (:obj:`torch.Tensor`):
|
|
Mask with ones indicating tokens to attend to, zeros for tokens to ignore.
|
|
input_shape (:obj:`Tuple[int]`):
|
|
The shape of the input to the model.
|
|
device: (:obj:`torch.device`):
|
|
The device of the input to the model.
|
|
|
|
Returns:
|
|
:obj:`torch.Tensor` The extended attention mask, with a the same dtype as :obj:`attention_mask.dtype`.
|
|
"""
|
|
# We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length]
|
|
# ourselves in which case we just need to make it broadcastable to all heads.
|
|
if attention_mask.dim() == 3:
|
|
extended_attention_mask = attention_mask[:, None, :, :]
|
|
elif attention_mask.dim() == 2:
|
|
# Provided a padding mask of dimensions [batch_size, seq_length]
|
|
# - if the model is a decoder, apply a causal mask in addition to the padding mask
|
|
# - if the model is an encoder, make the mask broadcastable to
|
|
# [batch_size, num_heads, seq_length, seq_length]
|
|
if is_decoder:
|
|
batch_size, seq_length = input_shape
|
|
seq_ids = torch.arange(seq_length, device=device)
|
|
causal_mask = seq_ids[None, None, :].repeat(
|
|
batch_size, seq_length, 1) <= seq_ids[None, :, None]
|
|
# in case past_key_values are used we need to add a prefix ones mask to the causal mask
|
|
# causal and attention masks must have same type with pytorch version < 1.3
|
|
causal_mask = causal_mask.to(attention_mask.dtype)
|
|
|
|
if causal_mask.shape[1] < attention_mask.shape[1]:
|
|
prefix_seq_len = attention_mask.shape[
|
|
1] - causal_mask.shape[1]
|
|
causal_mask = torch.cat(
|
|
[
|
|
torch.ones(
|
|
(batch_size, seq_length, prefix_seq_len),
|
|
device=device,
|
|
dtype=causal_mask.dtype),
|
|
causal_mask,
|
|
],
|
|
axis=-1,
|
|
)
|
|
|
|
extended_attention_mask = causal_mask[:,
|
|
None, :, :] * attention_mask[:,
|
|
None,
|
|
None, :]
|
|
else:
|
|
extended_attention_mask = attention_mask[:, None, None, :]
|
|
else:
|
|
raise ValueError(
|
|
'Wrong shape for input_ids (shape {}) or attention_mask (shape {})'
|
|
.format(input_shape, attention_mask.shape))
|
|
|
|
# Since attention_mask is 1.0 for positions we want to attend and 0.0 for
|
|
# masked positions, this operation will create a tensor which is 0.0 for
|
|
# positions we want to attend and -10000.0 for masked positions.
|
|
# Since we are adding it to the raw scores before the softmax, this is
|
|
# effectively the same as removing these entirely.
|
|
extended_attention_mask = extended_attention_mask.to(
|
|
dtype=self.dtype) # fp16 compatibility
|
|
extended_attention_mask = (1.0 - extended_attention_mask) * -10000.0
|
|
return extended_attention_mask
|
|
|
|
def forward(
|
|
self,
|
|
input_ids=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
encoder_embeds=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
past_key_values=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
is_decoder=False,
|
|
):
|
|
r"""
|
|
encoder_hidden_states
|
|
(:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`, `optional`):
|
|
Sequence of hidden-states at the output of the last layer of the encoder. Used in the cross-attention if
|
|
the model is configured as a decoder.
|
|
encoder_attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Mask to avoid performing attention on the padding token indices of the encoder input. This mask is used in
|
|
the cross-attention if the model is configured as a decoder. Mask values selected in ``[0, 1]``:
|
|
- 1 for tokens that are **not masked**,
|
|
- 0 for tokens that are **masked**.
|
|
past_key_values
|
|
(:obj:`tuple(tuple(torch.FloatTensor))` of length
|
|
:obj:`config.n_layers` with each tuple having 4 tensors of shape
|
|
:obj:`(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
|
|
Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.
|
|
If :obj:`past_key_values` are used, the user can optionally input only the last :obj:`decoder_input_ids`
|
|
(those that don't have their past key value states given to this model) of shape :obj:`(batch_size, 1)`
|
|
instead of all :obj:`decoder_input_ids` of shape :obj:`(batch_size, sequence_length)`.
|
|
use_cache (:obj:`bool`, `optional`):
|
|
If set to :obj:`True`, :obj:`past_key_values` key value states are returned and can be used to speed up
|
|
decoding (see :obj:`past_key_values`).
|
|
"""
|
|
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
|
|
output_hidden_states = (
|
|
output_hidden_states if output_hidden_states is not None else
|
|
self.config.output_hidden_states)
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
if is_decoder:
|
|
use_cache = use_cache if use_cache is not None else self.config.use_cache
|
|
else:
|
|
use_cache = False
|
|
|
|
if input_ids is not None and inputs_embeds is not None:
|
|
raise ValueError(
|
|
'You cannot specify both input_ids and inputs_embeds at the same time'
|
|
)
|
|
elif input_ids is not None:
|
|
input_shape = input_ids.size()
|
|
batch_size, seq_length = input_shape
|
|
device = input_ids.device
|
|
elif inputs_embeds is not None:
|
|
input_shape = inputs_embeds.size()[:-1]
|
|
batch_size, seq_length = input_shape
|
|
device = inputs_embeds.device
|
|
elif encoder_embeds is not None:
|
|
input_shape = encoder_embeds.size()[:-1]
|
|
batch_size, seq_length = input_shape
|
|
device = encoder_embeds.device
|
|
else:
|
|
raise ValueError(
|
|
'You have to specify either input_ids or inputs_embeds or encoder_embeds'
|
|
)
|
|
|
|
# past_key_values_length
|
|
past_key_values_length = past_key_values[0][0].shape[
|
|
2] if past_key_values is not None else 0
|
|
|
|
if attention_mask is None:
|
|
attention_mask = torch.ones(
|
|
((batch_size, seq_length + past_key_values_length)),
|
|
device=device)
|
|
if token_type_ids is None:
|
|
token_type_ids = torch.zeros(
|
|
input_shape, dtype=torch.long, device=device)
|
|
|
|
# We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length]
|
|
# ourselves in which case we just need to make it broadcastable to all heads.
|
|
extended_attention_mask: torch.Tensor = self.get_extended_attention_mask(
|
|
attention_mask, input_shape, device, is_decoder)
|
|
|
|
# If a 2D or 3D attention mask is provided for the cross-attention
|
|
# we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length]
|
|
if encoder_hidden_states is not None:
|
|
if type(encoder_hidden_states) == list:
|
|
encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states[
|
|
0].size()
|
|
else:
|
|
encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size(
|
|
)
|
|
encoder_hidden_shape = (encoder_batch_size,
|
|
encoder_sequence_length)
|
|
|
|
if type(encoder_attention_mask) == list:
|
|
encoder_extended_attention_mask = [
|
|
self.invert_attention_mask(mask)
|
|
for mask in encoder_attention_mask
|
|
]
|
|
elif encoder_attention_mask is None:
|
|
encoder_attention_mask = torch.ones(
|
|
encoder_hidden_shape, device=device)
|
|
encoder_extended_attention_mask = self.invert_attention_mask(
|
|
encoder_attention_mask)
|
|
else:
|
|
encoder_extended_attention_mask = self.invert_attention_mask(
|
|
encoder_attention_mask)
|
|
else:
|
|
encoder_extended_attention_mask = None
|
|
|
|
# Prepare head mask if needed
|
|
# 1.0 in head_mask indicate we keep the head
|
|
# attention_probs has shape bsz x n_heads x N x N
|
|
# input head_mask has shape [num_heads] or [num_hidden_layers x num_heads]
|
|
# and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length]
|
|
head_mask = self.get_head_mask(head_mask,
|
|
self.config.num_hidden_layers)
|
|
|
|
if encoder_embeds is None:
|
|
embedding_output = self.embeddings(
|
|
input_ids=input_ids,
|
|
position_ids=position_ids,
|
|
token_type_ids=token_type_ids,
|
|
inputs_embeds=inputs_embeds,
|
|
past_key_values_length=past_key_values_length,
|
|
)
|
|
else:
|
|
embedding_output = encoder_embeds
|
|
|
|
encoder_outputs = self.encoder(
|
|
embedding_output,
|
|
attention_mask=extended_attention_mask,
|
|
head_mask=head_mask,
|
|
encoder_hidden_states=encoder_hidden_states,
|
|
encoder_attention_mask=encoder_extended_attention_mask,
|
|
past_key_values=past_key_values,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict)
|
|
sequence_output = encoder_outputs[0]
|
|
pooled_output = self.pooler(
|
|
sequence_output) if self.pooler is not None else None
|
|
|
|
if not return_dict:
|
|
return (sequence_output, pooled_output) + encoder_outputs[1:]
|
|
|
|
return BaseModelOutputWithPoolingAndCrossAttentions(
|
|
last_hidden_state=sequence_output,
|
|
pooler_output=pooled_output,
|
|
past_key_values=encoder_outputs.past_key_values,
|
|
hidden_states=encoder_outputs.hidden_states,
|
|
attentions=encoder_outputs.attentions,
|
|
cross_attentions=encoder_outputs.cross_attentions,
|
|
)
|
|
|
|
|
|
class FusionModel(BertPreTrainedModel):
|
|
"""
|
|
The model can behave as an encoder (with only self-attention) as well as a decoder, in which case a layer of
|
|
cross-attention is added between the self-attention layers, following the architecture described in `Attention is
|
|
all you need <https://arxiv.org/abs/1706.03762>`__ by Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit,
|
|
Llion Jones, Aidan N. Gomez, Lukasz Kaiser and Illia Polosukhin.
|
|
argument and :obj:`add_cross_attention` set to :obj:`True`; an :obj:`encoder_hidden_states` is then expected as an
|
|
input to the forward pass.
|
|
"""
|
|
|
|
def __init__(self, config, add_pooling_layer=True):
|
|
super().__init__(config)
|
|
self.config = config
|
|
self.encoder = FusionEncoder(config)
|
|
self.pooler = BertPooler(config) if add_pooling_layer else None
|
|
|
|
self.init_weights()
|
|
|
|
def get_input_embeddings(self):
|
|
return self.embeddings.word_embeddings
|
|
|
|
def set_input_embeddings(self, value):
|
|
self.embeddings.word_embeddings = value
|
|
|
|
def _prune_heads(self, heads_to_prune):
|
|
"""
|
|
Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base
|
|
class PreTrainedModel
|
|
"""
|
|
for layer, heads in heads_to_prune.items():
|
|
self.encoder.layer[layer].attention.prune_heads(heads)
|
|
|
|
@add_start_docstrings_to_model_forward(
|
|
BERT_INPUTS_DOCSTRING.format('batch_size, sequence_length'))
|
|
@add_code_sample_docstrings(
|
|
# tokenizer_class=_TOKENIZER_FOR_DOC,
|
|
processor_class=_TOKENIZER_FOR_DOC,
|
|
checkpoint='bert-base-uncased',
|
|
output_type=BaseModelOutputWithPoolingAndCrossAttentions,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
def get_extended_attention_mask(self, attention_mask: Tensor,
|
|
input_shape: Tuple[int], device: device,
|
|
is_decoder: bool) -> Tensor:
|
|
"""
|
|
Makes broadcastable attention and causal masks so that future and masked tokens are ignored.
|
|
|
|
Arguments:
|
|
attention_mask (:obj:`torch.Tensor`):
|
|
Mask with ones indicating tokens to attend to, zeros for tokens to ignore.
|
|
input_shape (:obj:`Tuple[int]`):
|
|
The shape of the input to the model.
|
|
device: (:obj:`torch.device`):
|
|
The device of the input to the model.
|
|
|
|
Returns:
|
|
:obj:`torch.Tensor` The extended attention mask, with a the same dtype as :obj:`attention_mask.dtype`.
|
|
"""
|
|
# We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length]
|
|
# ourselves in which case we just need to make it broadcastable to all heads.
|
|
if attention_mask.dim() == 3:
|
|
extended_attention_mask = attention_mask[:, None, :, :]
|
|
elif attention_mask.dim() == 2:
|
|
# Provided a padding mask of dimensions [batch_size, seq_length]
|
|
# - if the model is a decoder, apply a causal mask in addition to the padding mask
|
|
# - if the model is an encoder, make the mask broadcastable to
|
|
# [batch_size, num_heads, seq_length, seq_length]
|
|
if is_decoder:
|
|
batch_size, seq_length = input_shape
|
|
seq_ids = torch.arange(seq_length, device=device)
|
|
causal_mask = seq_ids[None, None, :].repeat(
|
|
batch_size, seq_length, 1) <= seq_ids[None, :, None]
|
|
# in case past_key_values are used we need to add a prefix ones mask to the causal mask
|
|
# causal and attention masks must have same type with pytorch version < 1.3
|
|
causal_mask = causal_mask.to(attention_mask.dtype)
|
|
|
|
if causal_mask.shape[1] < attention_mask.shape[1]:
|
|
prefix_seq_len = attention_mask.shape[
|
|
1] - causal_mask.shape[1]
|
|
causal_mask = torch.cat(
|
|
[
|
|
torch.ones(
|
|
(batch_size, seq_length, prefix_seq_len),
|
|
device=device,
|
|
dtype=causal_mask.dtype),
|
|
causal_mask,
|
|
],
|
|
axis=-1,
|
|
)
|
|
|
|
extended_attention_mask = causal_mask[:,
|
|
None, :, :] * attention_mask[:,
|
|
None,
|
|
None, :]
|
|
else:
|
|
extended_attention_mask = attention_mask[:, None, None, :]
|
|
else:
|
|
raise ValueError(
|
|
'Wrong shape for input_ids (shape {}) or attention_mask (shape {})'
|
|
.format(input_shape, attention_mask.shape))
|
|
|
|
# Since attention_mask is 1.0 for positions we want to attend and 0.0 for
|
|
# masked positions, this operation will create a tensor which is 0.0 for
|
|
# positions we want to attend and -10000.0 for masked positions.
|
|
# Since we are adding it to the raw scores before the softmax, this is
|
|
# effectively the same as removing these entirely.
|
|
extended_attention_mask = extended_attention_mask.to(
|
|
dtype=self.dtype) # fp16 compatibility
|
|
extended_attention_mask = (1.0 - extended_attention_mask) * -10000.0
|
|
return extended_attention_mask
|
|
|
|
def forward(self,
|
|
input_ids=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
encoder_embeds=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
past_key_values=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
is_decoder=False):
|
|
r"""
|
|
encoder_hidden_states
|
|
(:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`, `optional`):
|
|
Sequence of hidden-states at the output of the last layer of the encoder. Used in the cross-attention if
|
|
the model is configured as a decoder.
|
|
encoder_attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Mask to avoid performing attention on the padding token indices of the encoder input. This mask is used in
|
|
the cross-attention if the model is configured as a decoder. Mask values selected in ``[0, 1]``:
|
|
- 1 for tokens that are **not masked**,
|
|
- 0 for tokens that are **masked**.
|
|
past_key_values
|
|
(:obj:`tuple(tuple(torch.FloatTensor))` of length
|
|
:obj:`config.n_layers` with each tuple having 4 tensors of shape
|
|
:obj:`(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
|
|
Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.
|
|
If :obj:`past_key_values` are used, the user can optionally input only the last :obj:`decoder_input_ids`
|
|
(those that don't have their past key value states given to this model) of shape :obj:`(batch_size, 1)`
|
|
instead of all :obj:`decoder_input_ids` of shape :obj:`(batch_size, sequence_length)`.
|
|
use_cache (:obj:`bool`, `optional`):
|
|
If set to :obj:`True`, :obj:`past_key_values` key value states are returned and can be used to speed up
|
|
decoding (see :obj:`past_key_values`).
|
|
"""
|
|
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
|
|
output_hidden_states = (
|
|
output_hidden_states if output_hidden_states is not None else
|
|
self.config.output_hidden_states)
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
if is_decoder:
|
|
use_cache = use_cache if use_cache is not None else self.config.use_cache
|
|
else:
|
|
use_cache = False
|
|
|
|
if input_ids is not None and inputs_embeds is not None:
|
|
raise ValueError(
|
|
'You cannot specify both input_ids and inputs_embeds at the same time'
|
|
)
|
|
elif input_ids is not None:
|
|
input_shape = input_ids.size()
|
|
batch_size, seq_length = input_shape
|
|
device = input_ids.device
|
|
elif inputs_embeds is not None:
|
|
input_shape = inputs_embeds.size()[:-1]
|
|
batch_size, seq_length = input_shape
|
|
device = inputs_embeds.device
|
|
elif encoder_embeds is not None:
|
|
input_shape = encoder_embeds.size()[:-1]
|
|
batch_size, seq_length = input_shape
|
|
device = encoder_embeds.device
|
|
else:
|
|
raise ValueError(
|
|
'You have to specify either input_ids or inputs_embeds or encoder_embeds'
|
|
)
|
|
|
|
# past_key_values_length
|
|
past_key_values_length = past_key_values[0][0].shape[
|
|
2] if past_key_values is not None else 0
|
|
|
|
if attention_mask is None:
|
|
attention_mask = torch.ones(
|
|
((batch_size, seq_length + past_key_values_length)),
|
|
device=device)
|
|
if token_type_ids is None:
|
|
token_type_ids = torch.zeros(
|
|
input_shape, dtype=torch.long, device=device)
|
|
|
|
# We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length]
|
|
# ourselves in which case we just need to make it broadcastable to all heads.
|
|
extended_attention_mask: torch.Tensor = self.get_extended_attention_mask(
|
|
attention_mask, input_shape, device, is_decoder)
|
|
|
|
# If a 2D or 3D attention mask is provided for the cross-attention
|
|
# we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length]
|
|
if encoder_hidden_states is not None:
|
|
if type(encoder_hidden_states) == list:
|
|
encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states[
|
|
0].size()
|
|
else:
|
|
encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size(
|
|
)
|
|
encoder_hidden_shape = (encoder_batch_size,
|
|
encoder_sequence_length)
|
|
|
|
if type(encoder_attention_mask) == list:
|
|
encoder_extended_attention_mask = [
|
|
self.invert_attention_mask(mask)
|
|
for mask in encoder_attention_mask
|
|
]
|
|
elif encoder_attention_mask is None:
|
|
encoder_attention_mask = torch.ones(
|
|
encoder_hidden_shape, device=device)
|
|
encoder_extended_attention_mask = self.invert_attention_mask(
|
|
encoder_attention_mask)
|
|
else:
|
|
encoder_extended_attention_mask = self.invert_attention_mask(
|
|
encoder_attention_mask)
|
|
else:
|
|
encoder_extended_attention_mask = None
|
|
|
|
# Prepare head mask if needed
|
|
# 1.0 in head_mask indicate we keep the head
|
|
# attention_probs has shape bsz x n_heads x N x N
|
|
# input head_mask has shape [num_heads] or [num_hidden_layers x num_heads]
|
|
# and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length]
|
|
head_mask = self.get_head_mask(head_mask,
|
|
self.config.num_hidden_layers)
|
|
|
|
if encoder_embeds is None:
|
|
embedding_output = self.embeddings(
|
|
input_ids=input_ids,
|
|
position_ids=position_ids,
|
|
token_type_ids=token_type_ids,
|
|
inputs_embeds=inputs_embeds,
|
|
past_key_values_length=past_key_values_length,
|
|
)
|
|
else:
|
|
embedding_output = encoder_embeds
|
|
|
|
encoder_outputs = self.encoder(
|
|
embedding_output,
|
|
attention_mask=extended_attention_mask,
|
|
head_mask=head_mask,
|
|
encoder_hidden_states=encoder_hidden_states,
|
|
encoder_attention_mask=encoder_extended_attention_mask,
|
|
past_key_values=past_key_values,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
encoder_hidden_states, sequence_output = encoder_outputs
|
|
pooled_output = self.pooler(
|
|
sequence_output) if self.pooler is not None else None
|
|
|
|
if not return_dict:
|
|
return [encoder_hidden_states, sequence_output]
|
|
|
|
return BaseModelOutputWithPoolingAndCrossAttentions(
|
|
last_hidden_state=sequence_output,
|
|
pooler_output=pooled_output,
|
|
past_key_values=encoder_outputs.past_key_values,
|
|
hidden_states=encoder_outputs.hidden_states,
|
|
attentions=encoder_outputs.attentions,
|
|
cross_attentions=encoder_outputs.cross_attentions,
|
|
)
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""Bert Model with a `language modeling` head on top for CLM fine-tuning. """,
|
|
BERT_START_DOCSTRING)
|
|
class BertLMHeadModel(BertPreTrainedModel):
|
|
|
|
_keys_to_ignore_on_load_unexpected = [r'pooler']
|
|
_keys_to_ignore_on_load_missing = [
|
|
r'position_ids', r'predictions.decoder.bias'
|
|
]
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
|
|
self.bert = BertModel(config, add_pooling_layer=False)
|
|
self.cls = BertOnlyMLMHead(config)
|
|
|
|
self.init_weights()
|
|
|
|
def get_output_embeddings(self):
|
|
return self.cls.predictions.decoder
|
|
|
|
def set_output_embeddings(self, new_embeddings):
|
|
self.cls.predictions.decoder = new_embeddings
|
|
|
|
@add_start_docstrings_to_model_forward(
|
|
BERT_INPUTS_DOCSTRING.format('batch_size, sequence_length'))
|
|
@replace_return_docstrings(
|
|
output_type=CausalLMOutputWithCrossAttentions,
|
|
config_class=_CONFIG_FOR_DOC)
|
|
def forward(
|
|
self,
|
|
input_ids=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
labels=None,
|
|
past_key_values=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
is_decoder=True,
|
|
reduction='mean',
|
|
soft_labels=None,
|
|
alpha=0,
|
|
return_logits=False,
|
|
):
|
|
r"""
|
|
encoder_hidden_states
|
|
(:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`, `optional`):
|
|
Sequence of hidden-states at the output of the last layer of the encoder. Used in the cross-attention if
|
|
the model is configured as a decoder.
|
|
encoder_attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Mask to avoid performing attention on the padding token indices of the encoder input. This mask is used in
|
|
the cross-attention if the model is configured as a decoder. Mask values selected in ``[0, 1]``:
|
|
- 1 for tokens that are **not masked**,
|
|
- 0 for tokens that are **masked**.
|
|
labels (:obj:`torch.LongTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Labels for computing the left-to-right language modeling loss (next word prediction). Indices should be in
|
|
``[-100, 0, ..., config.vocab_size]`` (see ``input_ids`` docstring) Tokens with indices set to ``-100`` are
|
|
ignored (masked), the loss is only computed for the tokens with labels n ``[0, ..., config.vocab_size]``
|
|
past_key_values
|
|
(:obj:`tuple(tuple(torch.FloatTensor))` of length
|
|
:obj:`config.n_layers` with each tuple having 4 tensors of shape
|
|
:obj:`(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
|
|
Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.
|
|
If :obj:`past_key_values` are used, the user can optionally input only the last :obj:`decoder_input_ids`
|
|
(those that don't have their past key value states given to this model) of shape :obj:`(batch_size, 1)`
|
|
instead of all :obj:`decoder_input_ids` of shape :obj:`(batch_size, sequence_length)`.
|
|
use_cache (:obj:`bool`, `optional`):
|
|
If set to :obj:`True`, :obj:`past_key_values` key value states are returned and can be used to speed up
|
|
decoding (see :obj:`past_key_values`).
|
|
Returns:
|
|
|
|
Example:
|
|
>>> from transformers import BertTokenizer, BertLMHeadModel, BertConfig
|
|
>>> import torch
|
|
>>> tokenizer = BertTokenizer.from_pretrained('bert-base-cased')
|
|
>>> config = BertConfig.from_pretrained("bert-base-cased")
|
|
>>> model = BertLMHeadModel.from_pretrained('bert-base-cased', config=config)
|
|
>>> inputs = tokenizer("Hello, my dog is cute", return_tensors="pt")
|
|
>>> outputs = model(**inputs)
|
|
>>> prediction_logits = outputs.logits
|
|
"""
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
if labels is not None:
|
|
use_cache = False
|
|
|
|
outputs = self.bert(
|
|
input_ids,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
head_mask=head_mask,
|
|
inputs_embeds=inputs_embeds,
|
|
encoder_hidden_states=encoder_hidden_states,
|
|
encoder_attention_mask=encoder_attention_mask,
|
|
past_key_values=past_key_values,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
is_decoder=is_decoder,
|
|
)
|
|
|
|
sequence_output = outputs[0]
|
|
prediction_scores = self.cls(sequence_output)
|
|
|
|
if return_logits:
|
|
return prediction_scores[:, :-1, :].contiguous()
|
|
|
|
lm_loss = None
|
|
if labels is not None:
|
|
# we are doing next-token prediction; shift prediction scores and input ids by one
|
|
shifted_prediction_scores = prediction_scores[:, :
|
|
-1, :].contiguous()
|
|
labels = labels[:, 1:].contiguous()
|
|
loss_fct = CrossEntropyLoss(reduction=reduction)
|
|
lm_loss = loss_fct(
|
|
shifted_prediction_scores.view(-1, self.config.vocab_size),
|
|
labels.view(-1))
|
|
lm_loss = lm_loss.view(prediction_scores.size(0), -1).sum(1)
|
|
|
|
if soft_labels is not None:
|
|
loss_distill = -torch.sum(
|
|
F.log_softmax(shifted_prediction_scores, dim=1) * soft_labels,
|
|
dim=-1)
|
|
loss_distill = (loss_distill * (labels != -100)).sum(1)
|
|
lm_loss = (1 - alpha) * lm_loss + alpha * loss_distill
|
|
|
|
if not return_dict:
|
|
output = (prediction_scores, ) + outputs[2:]
|
|
return ((lm_loss, ) + output) if lm_loss is not None else output
|
|
|
|
return CausalLMOutputWithCrossAttentions(
|
|
loss=lm_loss,
|
|
logits=prediction_scores,
|
|
past_key_values=outputs.past_key_values,
|
|
hidden_states=outputs.hidden_states,
|
|
attentions=outputs.attentions,
|
|
cross_attentions=outputs.cross_attentions,
|
|
)
|
|
|
|
def prepare_inputs_for_generation(self,
|
|
input_ids,
|
|
past=None,
|
|
attention_mask=None,
|
|
**model_kwargs):
|
|
input_shape = input_ids.shape
|
|
# if model is used as a decoder in encoder-decoder model, the decoder attention mask is created on the fly
|
|
if attention_mask is None:
|
|
attention_mask = input_ids.new_ones(input_shape)
|
|
|
|
# cut decoder_input_ids if past is used
|
|
if past is not None:
|
|
input_ids = input_ids[:, -1:]
|
|
|
|
return {
|
|
'input_ids':
|
|
input_ids,
|
|
'attention_mask':
|
|
attention_mask,
|
|
'past_key_values':
|
|
past,
|
|
'encoder_hidden_states':
|
|
model_kwargs.get('encoder_hidden_states', None),
|
|
'encoder_attention_mask':
|
|
model_kwargs.get('encoder_attention_mask', None),
|
|
'is_decoder':
|
|
True,
|
|
}
|
|
|
|
def _reorder_cache(self, past, beam_idx):
|
|
reordered_past = ()
|
|
for layer_past in past:
|
|
reordered_past += (tuple(
|
|
past_state.index_select(0, beam_idx)
|
|
for past_state in layer_past), )
|
|
return reordered_past
|
|
|
|
|
|
class BertPrefixModel(BertPreTrainedModel):
|
|
|
|
_keys_to_ignore_on_load_unexpected = [r'pooler']
|
|
_keys_to_ignore_on_load_missing = [
|
|
r'position_ids', r'predictions.decoder.bias'
|
|
]
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
|
|
self.bert = BertModel(config, add_pooling_layer=False)
|
|
self.cls = BertOnlyMLMHead(config)
|
|
|
|
self.init_weights()
|
|
|
|
def get_output_embeddings(self):
|
|
return self.cls.predictions.decoder
|
|
|
|
def set_output_embeddings(self, new_embeddings):
|
|
self.cls.predictions.decoder = new_embeddings
|
|
|
|
@add_start_docstrings_to_model_forward(
|
|
BERT_INPUTS_DOCSTRING.format('batch_size, sequence_length'))
|
|
@add_code_sample_docstrings(
|
|
processor_class=_TOKENIZER_FOR_DOC,
|
|
checkpoint='bert-base-uncased',
|
|
output_type=CausalLMOutputWithCrossAttentions,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
def forward(
|
|
self,
|
|
input_ids=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
encoder_hidden_states=None,
|
|
encoder_attention_mask=None,
|
|
labels=None,
|
|
past_key_values=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
is_decoder=True,
|
|
reduction='mean',
|
|
soft_labels=None,
|
|
alpha=0,
|
|
return_logits=False,
|
|
):
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
if labels is not None:
|
|
use_cache = False
|
|
|
|
outputs = self.bert(
|
|
input_ids,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
head_mask=head_mask,
|
|
inputs_embeds=inputs_embeds,
|
|
encoder_hidden_states=encoder_hidden_states,
|
|
encoder_attention_mask=encoder_attention_mask,
|
|
past_key_values=past_key_values,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
is_decoder=is_decoder,
|
|
)
|
|
|
|
sequence_output = outputs[0]
|
|
prediction_scores = self.cls(sequence_output)
|
|
|
|
if return_logits:
|
|
return prediction_scores[:, :-1, :].contiguous()
|
|
|
|
lm_loss = None
|
|
if labels is not None:
|
|
# we are doing next-token prediction; shift prediction scores and input ids by one
|
|
shifted_prediction_scores = prediction_scores[:, :
|
|
-1, :].contiguous()
|
|
labels = labels[:, 1:].contiguous()
|
|
loss_fct = CrossEntropyLoss()
|
|
lm_loss = loss_fct(
|
|
shifted_prediction_scores.view(-1, self.config.vocab_size),
|
|
labels.view(-1))
|
|
if soft_labels is not None:
|
|
loss_distill = -torch.sum(
|
|
F.log_softmax(shifted_prediction_scores, dim=1) * soft_labels,
|
|
dim=-1)
|
|
loss_distill = loss_distill[labels != -100].mean()
|
|
lm_loss = (1 - alpha) * lm_loss + alpha * loss_distill
|
|
|
|
if not return_dict:
|
|
output = (prediction_scores, ) + outputs[2:]
|
|
return ((lm_loss, ) + output) if lm_loss is not None else output
|
|
|
|
return CausalLMOutputWithCrossAttentions(
|
|
loss=lm_loss,
|
|
logits=prediction_scores,
|
|
past_key_values=outputs.past_key_values,
|
|
hidden_states=outputs.hidden_states,
|
|
attentions=outputs.attentions,
|
|
cross_attentions=outputs.cross_attentions,
|
|
)
|
|
|
|
|
|
class MPlug(PreTrainedModel):
|
|
config_class = MPlugConfig
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.config = config
|
|
self.tokenizer = BertTokenizer.from_pretrained(
|
|
os.path.join(config.model_dir, ModelFile.VOCAB_FILE))
|
|
self.module_setting(config)
|
|
self.visual_encoder = self._initialize_clip(config)
|
|
self.text_encoder = BertModel(
|
|
self.config_encoder, add_pooling_layer=False)
|
|
self.fusion_encoder = FusionModel(
|
|
self.config_fusion, add_pooling_layer=False)
|
|
|
|
@classmethod
|
|
def from_pretrained(cls, model_dir, task=None, load_checkpoint=True):
|
|
from modelscope.utils.constant import Tasks
|
|
|
|
task_mapping = {
|
|
Tasks.visual_question_answering: MPlugForVisualQuestionAnswering,
|
|
Tasks.image_captioning: MPlugForImageCaption,
|
|
Tasks.image_text_retrieval: MPlugForImageTextRetrieval,
|
|
}
|
|
config = cls.config_class.from_yaml_file(
|
|
os.path.join(model_dir, CONFIG_NAME))
|
|
config.model_dir = model_dir
|
|
if task is None:
|
|
task = config.task
|
|
model = task_mapping[task](config)
|
|
if load_checkpoint:
|
|
checkpoint_path = os.path.join(model_dir,
|
|
ModelFile.TORCH_MODEL_BIN_FILE)
|
|
checkpoint = torch.load(checkpoint_path, map_location='cpu')
|
|
if 'model' in checkpoint:
|
|
checkpoint = checkpoint['model']
|
|
if 'module' in checkpoint:
|
|
checkpoint = checkpoint['module']
|
|
checkpoint = {
|
|
k.replace('model.', ''): v
|
|
for k, v in checkpoint.items()
|
|
}
|
|
|
|
msg = model.load_state_dict(checkpoint, strict=False)
|
|
print('load checkpoint from %s' % checkpoint_path)
|
|
print(msg)
|
|
return model
|
|
|
|
@staticmethod
|
|
def _initialize_clip(config, num_patches=240):
|
|
|
|
def resize_pos_embed(posemb, posemb_new):
|
|
# Rescale the grid of position embeddings when loading from state_dict. Adapted from
|
|
# https://github.com/google-research/vision_transformer/blob/00883dd691c63a6830751563748663526e811cee/vit_jax/checkpoint.py#L224
|
|
ntok_new = posemb_new.shape[1]
|
|
|
|
posemb_tok, posemb_grid = posemb[:, :1], posemb[0, 1:]
|
|
ntok_new -= 1
|
|
|
|
gs_old = int(math.sqrt(len(posemb_grid)))
|
|
gs_new = int(math.sqrt(ntok_new))
|
|
# _logger.info('Position embedding grid-size from %s to %s', gs_old, gs_new)
|
|
posemb_grid = posemb_grid.reshape(1, gs_old, gs_old,
|
|
-1).permute(0, 3, 1, 2)
|
|
orig = posemb_grid.dtype
|
|
posemb_grid = F.interpolate(
|
|
posemb_grid.float(), size=(gs_new, gs_new), mode='bilinear')
|
|
posemb_grid = posemb_grid.to(orig)
|
|
posemb_grid = posemb_grid.permute(0, 2, 3, 1).reshape(
|
|
1, gs_new * gs_new, -1)
|
|
posemb = torch.cat([posemb_tok, posemb_grid], dim=1)
|
|
return posemb
|
|
|
|
from .clip import clip
|
|
clip_model = clip.load_from_config(config)
|
|
if 'ViT-B-16' in config.clip_name:
|
|
num_patches = int(config.image_res * config.image_res / (16 * 16))
|
|
pos_embed = nn.Parameter(torch.zeros(num_patches + 1, 768).float())
|
|
else:
|
|
num_patches = int(config.image_res * config.image_res / (14 * 14))
|
|
pos_embed = nn.Parameter(
|
|
torch.zeros(num_patches + 1, 1024).float())
|
|
pos_embed.weight = resize_pos_embed(
|
|
clip_model.visual.positional_embedding.unsqueeze(0),
|
|
pos_embed.unsqueeze(0))
|
|
clip_model.visual.positional_embedding = pos_embed
|
|
return clip_model
|
|
|
|
def init_distill(self, config):
|
|
self.distill = config.distill
|
|
if self.distill:
|
|
self.visual_encoder_m = self._initialize_clip(config)
|
|
self.text_encoder_m = BertModel(
|
|
self.config_encoder, add_pooling_layer=False)
|
|
self.fusion_encoder_m = FusionModel(
|
|
self.config_fusion, add_pooling_layer=False)
|
|
self.text_decoder_m = BertLMHeadModel(self.config_decoder)
|
|
self.model_pairs = [
|
|
[self.visual_encoder, self.visual_encoder_m],
|
|
[self.text_encoder, self.text_encoder_m],
|
|
[self.text_decoder, self.text_decoder_m],
|
|
]
|
|
if self.config_encoder.hidden_size != config.vision_width:
|
|
self.visn_fc_m = nn.Linear(config.vision_width,
|
|
self.config_encoder.hidden_size)
|
|
self.visn_layer_norm_m = nn.LayerNorm(
|
|
self.config_encoder.hidden_size, eps=1e-12)
|
|
self.dropout_m = nn.Dropout(
|
|
self.config_encoder.hidden_dropout_prob)
|
|
self.model_pairs.extend(
|
|
[[self.visn_fc, self.visn_fc_m],
|
|
[self.visn_layer_norm, self.visn_layer_norm_m]])
|
|
self.copy_params()
|
|
self.momentum = 0.995
|
|
|
|
def forward(self, *args, **kwargs):
|
|
raise NotImplementedError
|
|
|
|
def module_setting(self, config):
|
|
bert_config_path = os.path.join(config.model_dir, config.bert_config)
|
|
self.config_encoder = BertConfig.from_json_file(bert_config_path)
|
|
self.config_encoder.num_hidden_layers = self.config_encoder.text_encoder_layers
|
|
self.config_fusion = BertConfig.from_json_file(bert_config_path)
|
|
self.config_decoder = BertConfig.from_json_file(bert_config_path)
|
|
self.config_decoder.add_cross_attention = True
|
|
self.config_decoder.num_hidden_layers = self.config_decoder.text_decode_layers
|
|
self.large = False
|
|
if self.config_encoder.hidden_size != config.vision_width:
|
|
self.visn_fc = nn.Linear(config.vision_width,
|
|
self.config_encoder.hidden_size)
|
|
self.visn_layer_norm = nn.LayerNorm(
|
|
self.config_encoder.hidden_size, eps=1e-12)
|
|
self.dropout = nn.Dropout(self.config_encoder.hidden_dropout_prob)
|
|
self.large = True
|
|
|
|
@torch.no_grad()
|
|
def copy_params(self):
|
|
for model_pair in self.model_pairs:
|
|
for param, param_m in zip(model_pair[0].parameters(),
|
|
model_pair[1].parameters()):
|
|
param_m.data.copy_(param.data) # initialize
|
|
param_m.requires_grad = False # not update by gradient
|
|
|
|
@torch.no_grad()
|
|
def _momentum_update(self):
|
|
for model_pair in self.model_pairs:
|
|
for param, param_m in zip(model_pair[0].parameters(),
|
|
model_pair[1].parameters()):
|
|
param_m.data = param_m.data * self.momentum + param.data * (
|
|
1. - self.momentum)
|
|
|
|
def generation(self, question_states, question_atts, out_size=1):
|
|
encoder_inputs = [question_states, question_atts]
|
|
topk_ids, topk_scores = self.beam_generator.translate_batch(
|
|
encoder_inputs, out_size=out_size)
|
|
return topk_ids, topk_scores
|
|
|
|
@staticmethod
|
|
def _tile(x, dim, n_tile):
|
|
import numpy as np
|
|
init_dim = x.size(dim)
|
|
repeat_idx = [1] * x.dim()
|
|
repeat_idx[dim] = n_tile
|
|
x = x.repeat(*(repeat_idx))
|
|
order_index = torch.LongTensor(
|
|
np.concatenate(
|
|
[init_dim * np.arange(n_tile) + i for i in range(init_dim)]))
|
|
return torch.index_select(x, dim, order_index.to(x.device))
|
|
|
|
|
|
class MPlugForVisualQuestionAnswering(MPlug):
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.text_decoder = BertLMHeadModel(self.config_decoder)
|
|
self.beam_generator = TextGenerator(config, self.text_decoder)
|
|
self.init_distill(config)
|
|
|
|
def forward(self,
|
|
image,
|
|
question,
|
|
answer=None,
|
|
alpha=0,
|
|
k=None,
|
|
weights=None,
|
|
train=True):
|
|
image = image.to(dtype=next(self.parameters()).dtype)
|
|
image_embeds = self.visual_encoder.visual(image, skip_last_layer=True)
|
|
if self.large:
|
|
image_embeds = self.dropout(
|
|
self.visn_layer_norm(self.visn_fc(image_embeds)))
|
|
image_atts = torch.ones(
|
|
image_embeds.size()[:-1], dtype=torch.long).to(image.device)
|
|
|
|
if train:
|
|
'''
|
|
k: number of answers for each question
|
|
weights: weight for each answer
|
|
'''
|
|
answer_targets = answer.input_ids.masked_fill(
|
|
answer.input_ids == self.tokenizer.pad_token_id, -100)
|
|
text_output = self.text_encoder(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
fusion_output = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=image_embeds,
|
|
encoder_attention_mask=image_atts,
|
|
return_dict=False)
|
|
|
|
image_output, question_output = fusion_output
|
|
|
|
question_output = torch.cat([image_output, question_output], 1)
|
|
merge_text_attention = torch.cat(
|
|
[image_atts, question.attention_mask], 1)
|
|
|
|
if k is None:
|
|
k = [1] * question_output.shape[0]
|
|
question_states = []
|
|
question_atts = []
|
|
for b, n in enumerate(k):
|
|
question_states += [question_output[b]] * n
|
|
question_atts += [merge_text_attention[b]] * n
|
|
question_states = torch.stack(question_states, 0)
|
|
question_atts = torch.stack(question_atts, 0)
|
|
|
|
if self.distill:
|
|
with torch.no_grad():
|
|
self._momentum_update()
|
|
image_embeds_m = self.visual_encoder_m.visual(
|
|
image, skip_last_layer=True)
|
|
if self.large:
|
|
image_embeds_m = self.dropout_m(
|
|
self.visn_layer_norm_m(
|
|
self.visn_fc_m(image_embeds_m)))
|
|
text_output_m = self.text_encoder_m(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds_m = text_output_m.last_hidden_state
|
|
fusion_output_m = self.fusion_encoder_m(
|
|
encoder_embeds=text_embeds_m,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=image_embeds_m,
|
|
encoder_attention_mask=image_atts,
|
|
return_dict=False)
|
|
|
|
image_output_m, question_output_m = fusion_output_m
|
|
question_output_m = torch.cat(
|
|
[image_output_m, question_output_m], 1)
|
|
|
|
question_states_m = []
|
|
for b, n in enumerate(k):
|
|
question_states_m += [question_output_m[b]] * n
|
|
question_states_m = torch.stack(question_states_m, 0)
|
|
|
|
logits_m = self.text_decoder_m(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=question_states_m,
|
|
encoder_attention_mask=question_atts,
|
|
return_logits=True,
|
|
)
|
|
|
|
answer_output = self.text_decoder(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=question_states,
|
|
encoder_attention_mask=question_atts,
|
|
labels=answer_targets,
|
|
return_dict=True,
|
|
soft_labels=F.softmax(logits_m, dim=-1),
|
|
reduction='none',
|
|
)
|
|
else:
|
|
answer_output = self.text_decoder(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=question_states,
|
|
encoder_attention_mask=question_atts,
|
|
labels=answer_targets,
|
|
return_dict=True,
|
|
reduction='none',
|
|
)
|
|
if weights is None:
|
|
weights = 1
|
|
loss = weights * answer_output.loss
|
|
loss = loss.sum() / image.size(0)
|
|
|
|
return loss
|
|
|
|
else:
|
|
text_output = self.text_encoder(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
fusion_output = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=image_embeds,
|
|
encoder_attention_mask=image_atts,
|
|
return_dict=False)
|
|
image_output, question_output = fusion_output
|
|
question_output = torch.cat([image_output, question_output], 1)
|
|
merge_text_attention = torch.cat(
|
|
[image_atts, question.attention_mask], 1)
|
|
topk_ids, topk_probs = self.generation(question_output,
|
|
merge_text_attention)
|
|
return topk_ids, topk_probs
|
|
|
|
|
|
class MPlugForImageCaption(MPlug):
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.text_decoder = BertPrefixModel(self.config_decoder)
|
|
self.beam_generator = TextGenerator(config, self.text_decoder)
|
|
|
|
def beam_search(self,
|
|
image,
|
|
question,
|
|
answer=None,
|
|
train=True,
|
|
out_size=5):
|
|
image_embeds = self.visual_encoder.visual(image, skip_last_layer=True)
|
|
if self.large:
|
|
image_embeds = self.dropout(
|
|
self.visn_layer_norm(self.visn_fc(image_embeds)))
|
|
image_atts = torch.ones(
|
|
image_embeds.size()[:-1], dtype=torch.long).to(image.device)
|
|
text_output = self.text_encoder(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
fusion_output = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=image_embeds,
|
|
encoder_attention_mask=image_atts,
|
|
return_dict=False)
|
|
image_output, question_output = fusion_output
|
|
question_output = torch.cat([image_output, question_output], 1)
|
|
merge_text_attention = torch.cat([image_atts, question.attention_mask],
|
|
1)
|
|
topk_ids, topk_probs = self.generation(
|
|
question_output, merge_text_attention, out_size=out_size)
|
|
return topk_ids, topk_probs
|
|
|
|
def forward(self,
|
|
image,
|
|
question,
|
|
answer=None,
|
|
train=True,
|
|
out_size=5,
|
|
scst=False):
|
|
if (scst):
|
|
return self.beam_search(
|
|
image, question, answer, train=True, out_size=out_size)
|
|
image = image.to(dtype=next(self.parameters()).dtype)
|
|
image_embeds = self.visual_encoder.visual(image, skip_last_layer=True)
|
|
if self.large:
|
|
image_embeds = self.dropout(
|
|
self.visn_layer_norm(self.visn_fc(image_embeds)))
|
|
image_atts = torch.ones(
|
|
image_embeds.size()[:-1], dtype=torch.long).to(image.device)
|
|
|
|
if train:
|
|
answer_targets = answer.input_ids.masked_fill(
|
|
answer.input_ids == self.tokenizer.pad_token_id, -100)
|
|
answer_output = self.text_decoder(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=image_embeds,
|
|
encoder_attention_mask=image_atts,
|
|
labels=answer_targets,
|
|
return_dict=True,
|
|
reduction='none')
|
|
loss = answer_output.loss
|
|
|
|
return loss
|
|
else:
|
|
topk_ids, topk_probs = self.generation(image_embeds, image_atts)
|
|
return topk_ids, topk_probs
|
|
|
|
|
|
class MPlugForImageTextRetrieval(MPlug):
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.embed_dim = config.embed_dim
|
|
self.temp = nn.Parameter(torch.ones([]) * config.temp)
|
|
self.queue_size = config.queue_size
|
|
self.momentum = config.momentum
|
|
self.alpha = config.alpha
|
|
|
|
self.queue_size = config.queue_size
|
|
self.text_width = self.config_encoder.hidden_size
|
|
self.embed_dim = config.embed_dim
|
|
|
|
self.vision_proj = nn.Linear(self.text_width, self.embed_dim)
|
|
self.text_proj = nn.Linear(self.text_width, self.embed_dim)
|
|
self.itm_head = nn.Linear(self.text_width, 2)
|
|
|
|
self.register_buffer('image_queue',
|
|
torch.randn(self.embed_dim, self.queue_size))
|
|
self.register_buffer('text_queue',
|
|
torch.randn(self.embed_dim, self.queue_size))
|
|
self.register_buffer('idx_queue', torch.full((1, self.queue_size),
|
|
-100))
|
|
self.register_buffer('queue_ptr', torch.zeros(1, dtype=torch.long))
|
|
|
|
self.image_queue = F.normalize(self.image_queue, dim=0)
|
|
self.text_queue = F.normalize(self.text_queue, dim=0)
|
|
self.init_distill(config)
|
|
|
|
def init_distill(self, config):
|
|
self.distill = config.distill
|
|
if self.distill:
|
|
self.visual_encoder_m = self._initialize_clip(config)
|
|
self.text_encoder_m = BertModel(
|
|
self.config_encoder, add_pooling_layer=False)
|
|
self.fusion_encoder_m = FusionModel(
|
|
self.config_fusion, add_pooling_layer=False)
|
|
self.vision_proj_m = nn.Linear(self.text_width, self.embed_dim)
|
|
self.text_proj_m = nn.Linear(self.text_width, self.embed_dim)
|
|
self.model_pairs = [
|
|
[self.visual_encoder, self.visual_encoder_m],
|
|
[self.text_encoder, self.text_encoder_m],
|
|
[self.text_proj, self.text_proj_m],
|
|
[self.vision_proj, self.vision_proj_m],
|
|
]
|
|
if self.config_encoder.hidden_size != config.vision_width:
|
|
self.visn_fc_m = nn.Linear(config.vision_width,
|
|
self.config_encoder.hidden_size)
|
|
self.visn_layer_norm_m = nn.LayerNorm(
|
|
self.config_encoder.hidden_size, eps=1e-12)
|
|
self.dropout_m = nn.Dropout(
|
|
self.config_encoder.hidden_dropout_prob)
|
|
self.model_pairs.extend(
|
|
[[self.visn_fc, self.visn_fc_m],
|
|
[self.visn_layer_norm, self.visn_layer_norm_m]])
|
|
self.copy_params()
|
|
self.momentum = 0.995
|
|
|
|
@torch.no_grad()
|
|
def _dequeue_and_enqueue(self, image_feat, text_feat, idx):
|
|
|
|
def concat_all_gather(tensor):
|
|
"""
|
|
Performs all_gather operation on the provided tensors.
|
|
*** Warning ***: torch.distributed.all_gather has no gradient.
|
|
"""
|
|
if not torch.distributed.is_initialized():
|
|
return tensor
|
|
tensors_gather = [
|
|
torch.ones_like(tensor)
|
|
for _ in range(torch.distributed.get_world_size())
|
|
]
|
|
torch.distributed.all_gather(
|
|
tensors_gather, tensor, async_op=False)
|
|
|
|
output = torch.cat(tensors_gather, dim=0)
|
|
return output
|
|
|
|
# gather keys before updating queue
|
|
image_feats = concat_all_gather(image_feat)
|
|
text_feats = concat_all_gather(text_feat)
|
|
idxs = concat_all_gather(idx)
|
|
|
|
batch_size = image_feats.shape[0]
|
|
|
|
ptr = int(self.queue_ptr)
|
|
# assert self.queue_size % batch_size == 0 # for simplicity
|
|
|
|
# replace the keys at ptr (dequeue and enqueue)
|
|
self.image_queue[:, ptr:ptr + batch_size] = image_feats.T
|
|
self.text_queue[:, ptr:ptr + batch_size] = text_feats.T
|
|
self.idx_queue[:, ptr:ptr + batch_size] = idxs.T
|
|
ptr = (ptr + batch_size) % self.queue_size # move pointer
|
|
|
|
self.queue_ptr[0] = ptr
|
|
|
|
def forward(self, image, text, idx=None, train=True):
|
|
if train:
|
|
image_embeds = self.visual_encoder.visual(
|
|
image, skip_last_layer=True)
|
|
if self.large:
|
|
image_embeds = self.dropout(
|
|
self.visn_layer_norm(self.visn_fc(image_embeds)))
|
|
image_atts = torch.ones(
|
|
image_embeds.size()[:-1], dtype=torch.long).to(image.device)
|
|
|
|
image_feat = F.normalize(
|
|
self.vision_proj(image_embeds[:, 0, :]), dim=-1)
|
|
text_output = self.text_encoder(
|
|
text.input_ids,
|
|
attention_mask=text.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
text_feat = F.normalize(
|
|
self.text_proj(text_embeds[:, 0, :]), dim=-1)
|
|
|
|
idx = idx.view(-1, 1)
|
|
idx_all = torch.cat(
|
|
[idx.t(), self.idx_queue.clone().detach()], dim=1)
|
|
pos_idx = torch.eq(idx, idx_all).float()
|
|
sim_targets = pos_idx / pos_idx.sum(1, keepdim=True)
|
|
|
|
with torch.no_grad():
|
|
self._momentum_update()
|
|
image_embeds_m = self.visual_encoder_m.visual(
|
|
image, skip_last_layer=True)
|
|
if self.large:
|
|
image_embeds_m = self.dropout_m(
|
|
self.visn_layer_norm_m(self.visn_fc_m(image_embeds_m)))
|
|
image_feat_m = F.normalize(
|
|
self.vision_proj_m(image_embeds_m[:, 0, :]), dim=-1)
|
|
image_feat_all = torch.cat(
|
|
[image_feat_m.t(),
|
|
self.image_queue.clone().detach()],
|
|
dim=1)
|
|
text_output_m = self.text_encoder_m(
|
|
text.input_ids,
|
|
attention_mask=text.attention_mask,
|
|
return_dict=True)
|
|
text_feat_m = F.normalize(
|
|
self.text_proj_m(text_output_m.last_hidden_state[:, 0, :]),
|
|
dim=-1)
|
|
text_feat_all = torch.cat(
|
|
[text_feat_m.t(),
|
|
self.text_queue.clone().detach()], dim=1)
|
|
|
|
if self.distill:
|
|
sim_i2t_m = image_feat_m @ text_feat_all / self.temp
|
|
sim_t2i_m = text_feat_m @ image_feat_all / self.temp
|
|
|
|
sim_i2t_targets = self.alpha * F.softmax(
|
|
sim_i2t_m, dim=1) + (1 - self.alpha) * sim_targets
|
|
sim_t2i_targets = self.alpha * F.softmax(
|
|
sim_t2i_m, dim=1) + (1 - self.alpha) * sim_targets
|
|
|
|
sim_i2t = image_feat @ text_feat_all / self.temp
|
|
sim_t2i = text_feat @ image_feat_all / self.temp
|
|
|
|
if self.distill:
|
|
loss_i2t = -torch.sum(
|
|
F.log_softmax(sim_i2t, dim=1) * sim_i2t_targets,
|
|
dim=1).mean()
|
|
loss_t2i = -torch.sum(
|
|
F.log_softmax(sim_t2i, dim=1) * sim_t2i_targets,
|
|
dim=1).mean()
|
|
else:
|
|
loss_i2t = -torch.sum(
|
|
F.log_softmax(sim_i2t, dim=1) * sim_targets, dim=1).mean()
|
|
loss_t2i = -torch.sum(
|
|
F.log_softmax(sim_t2i, dim=1) * sim_targets, dim=1).mean()
|
|
|
|
loss_ita = (loss_i2t + loss_t2i) / 2
|
|
|
|
self._dequeue_and_enqueue(image_feat_m, text_feat_m, idx)
|
|
|
|
# forward the positve image-text pair
|
|
_, output_pos = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=text.attention_mask,
|
|
encoder_hidden_states=image_embeds,
|
|
encoder_attention_mask=image_atts,
|
|
return_dict=False,
|
|
)
|
|
with torch.no_grad():
|
|
bs = image.size(0)
|
|
weights_i2t = F.softmax(sim_i2t[:, :bs], dim=1)
|
|
weights_t2i = F.softmax(sim_t2i[:, :bs], dim=1)
|
|
|
|
mask = torch.eq(idx, idx.T)
|
|
weights_i2t.masked_fill_(mask, 0)
|
|
weights_t2i.masked_fill_(mask, 0)
|
|
|
|
# select a negative image for each text
|
|
image_embeds_neg = []
|
|
for b in range(bs):
|
|
neg_idx = torch.multinomial(weights_t2i[b], 1).item()
|
|
image_embeds_neg.append(image_embeds[neg_idx])
|
|
image_embeds_neg = torch.stack(image_embeds_neg, dim=0)
|
|
|
|
# select a negative text for each image
|
|
text_embeds_neg = []
|
|
text_atts_neg = []
|
|
for b in range(bs):
|
|
neg_idx = torch.multinomial(weights_i2t[b], 1).item()
|
|
text_embeds_neg.append(text_embeds[neg_idx])
|
|
text_atts_neg.append(text.attention_mask[neg_idx])
|
|
text_embeds_neg = torch.stack(text_embeds_neg, dim=0)
|
|
text_atts_neg = torch.stack(text_atts_neg, dim=0)
|
|
|
|
text_embeds_all = torch.cat([text_embeds, text_embeds_neg], dim=0)
|
|
text_atts_all = torch.cat([text.attention_mask, text_atts_neg],
|
|
dim=0)
|
|
|
|
image_embeds_all = torch.cat([image_embeds_neg, image_embeds],
|
|
dim=0)
|
|
image_atts_all = torch.cat([image_atts, image_atts], dim=0)
|
|
|
|
_, output_neg = self.fusion_encoder(
|
|
encoder_embeds=text_embeds_all,
|
|
attention_mask=text_atts_all,
|
|
encoder_hidden_states=image_embeds_all,
|
|
encoder_attention_mask=image_atts_all,
|
|
return_dict=False,
|
|
)
|
|
|
|
vl_embeddings = torch.cat(
|
|
[output_pos[:, 0, :], output_neg[:, 0, :]], dim=0)
|
|
vl_output = self.itm_head(vl_embeddings)
|
|
|
|
ones_tmp = torch.ones(bs, dtype=torch.long)
|
|
zeros_tmp = torch.zeros(2 * bs, dtype=torch.long)
|
|
itm_labels = torch.cat([ones_tmp, zeros_tmp],
|
|
dim=0).to(image.device)
|
|
loss_itm = F.cross_entropy(vl_output, itm_labels)
|
|
|
|
return loss_ita + loss_itm
|
|
else:
|
|
text_output = self.text_encoder(
|
|
text.input_ids, attention_mask=text.attention_mask)
|
|
text_feat = text_output.last_hidden_state
|
|
image_feat = self.visual_encoder.visual(
|
|
image, skip_last_layer=True)
|
|
image_feat = self.visn_layer_norm(self.visn_fc(image_feat))
|
|
image_att = torch.ones(
|
|
image_feat.size()[:-1],
|
|
dtype=torch.long,
|
|
device=image_feat.device)
|
|
_, output = self.fusion_encoder(
|
|
encoder_embeds=text_feat,
|
|
attention_mask=text.attention_mask,
|
|
encoder_hidden_states=image_feat,
|
|
encoder_attention_mask=image_att,
|
|
return_dict=False,
|
|
)
|
|
scores = self.itm_head(output[:, 0, :])
|
|
scores = F.softmax(scores, dim=-1)
|
|
|
|
return scores
|
|
|
|
|
|
class HiTeA(PreTrainedModel):
|
|
config_class = HiTeAConfig
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.config = config
|
|
self.tokenizer = BertTokenizer.from_pretrained(
|
|
os.path.join(config.model_dir, ModelFile.VOCAB_FILE))
|
|
self.module_setting(config)
|
|
self.visual_encoder = MViTv2(
|
|
img_size=config.image_res,
|
|
config=MViTv2_Base_config,
|
|
num_frames=config.num_frames)
|
|
self.text_encoder = BertModel(
|
|
self.config_encoder, add_pooling_layer=False)
|
|
self.fusion_encoder = FusionModel(
|
|
self.config_fusion, add_pooling_layer=False)
|
|
|
|
@classmethod
|
|
def from_pretrained(cls, model_dir, load_checkpoint=True):
|
|
from modelscope.utils.constant import Tasks
|
|
|
|
task_mapping = {
|
|
Tasks.video_question_answering: HiTeAForVideoQuestionAnswering,
|
|
Tasks.video_captioning: HiTeAForVideoCaption,
|
|
}
|
|
config = cls.config_class.from_yaml_file(
|
|
os.path.join(model_dir, CONFIG_NAME))
|
|
config.model_dir = model_dir
|
|
model = task_mapping[config.task](config)
|
|
if load_checkpoint:
|
|
checkpoint_path = os.path.join(model_dir,
|
|
ModelFile.TORCH_MODEL_BIN_FILE)
|
|
checkpoint = torch.load(checkpoint_path, map_location='cpu')
|
|
if 'model' in checkpoint:
|
|
checkpoint = checkpoint['model']
|
|
if 'module' in checkpoint:
|
|
checkpoint = checkpoint['module']
|
|
checkpoint = {
|
|
k.replace('model.', ''): v
|
|
for k, v in checkpoint.items()
|
|
}
|
|
|
|
model.load_state_dict(checkpoint, strict=False)
|
|
return model
|
|
|
|
def init_distill(self, config):
|
|
self.distill = config.distill
|
|
if self.distill:
|
|
self.visual_encoder_m = MViTv2(
|
|
img_size=config.image_res,
|
|
config=MViTv2_Base_config,
|
|
num_frames=config.num_frames)
|
|
self.text_encoder_m = BertModel(
|
|
self.config_encoder, add_pooling_layer=False)
|
|
self.fusion_encoder_m = FusionModel(
|
|
self.config_fusion, add_pooling_layer=False)
|
|
self.text_decoder_m = BertLMHeadModel(self.config_decoder)
|
|
self.model_pairs = [
|
|
[self.visual_encoder, self.visual_encoder_m],
|
|
[self.text_encoder, self.text_encoder_m],
|
|
[self.text_decoder, self.text_decoder_m],
|
|
]
|
|
self.copy_params()
|
|
self.momentum = 0.995
|
|
|
|
def forward(self, *args, **kwargs):
|
|
raise NotImplementedError
|
|
|
|
def module_setting(self, config):
|
|
bert_config_path = os.path.join(config.model_dir, config.bert_config)
|
|
self.config_encoder = BertConfig.from_json_file(bert_config_path)
|
|
self.config_encoder.num_hidden_layers = self.config_encoder.text_encoder_layers
|
|
self.config_fusion = BertConfig.from_json_file(bert_config_path)
|
|
self.config_decoder = BertConfig.from_json_file(bert_config_path)
|
|
self.config_decoder.add_cross_attention = True
|
|
self.config_decoder.num_hidden_layers = self.config_decoder.text_decode_layers
|
|
|
|
@torch.no_grad()
|
|
def copy_params(self):
|
|
for model_pair in self.model_pairs:
|
|
for param, param_m in zip(model_pair[0].parameters(),
|
|
model_pair[1].parameters()):
|
|
param_m.data.copy_(param.data) # initialize
|
|
param_m.requires_grad = False # not update by gradient
|
|
|
|
@torch.no_grad()
|
|
def _momentum_update(self):
|
|
for model_pair in self.model_pairs:
|
|
for param, param_m in zip(model_pair[0].parameters(),
|
|
model_pair[1].parameters()):
|
|
param_m.data = param_m.data * self.momentum + param.data * (
|
|
1. - self.momentum)
|
|
|
|
def generation(self, question_states, question_atts, out_size=1):
|
|
encoder_inputs = [question_states, question_atts]
|
|
topk_ids, topk_scores = self.beam_generator.translate_batch(
|
|
encoder_inputs, out_size=out_size)
|
|
return topk_ids, topk_scores
|
|
|
|
@staticmethod
|
|
def _tile(x, dim, n_tile):
|
|
import numpy as np
|
|
init_dim = x.size(dim)
|
|
repeat_idx = [1] * x.dim()
|
|
repeat_idx[dim] = n_tile
|
|
x = x.repeat(*(repeat_idx))
|
|
order_index = torch.LongTensor(
|
|
np.concatenate(
|
|
[init_dim * np.arange(n_tile) + i for i in range(init_dim)]))
|
|
return torch.index_select(x, dim, order_index.to(x.device))
|
|
|
|
|
|
class HiTeAForVideoQuestionAnswering(HiTeA):
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.text_decoder = BertLMHeadModel(self.config_decoder)
|
|
self.beam_generator = TextGenerator(config, self.text_decoder)
|
|
self.init_distill(config)
|
|
|
|
def forward(self,
|
|
video,
|
|
question,
|
|
answer=None,
|
|
alpha=0,
|
|
k=None,
|
|
weights=None,
|
|
train=True):
|
|
video = video.to(dtype=next(self.parameters()).dtype)
|
|
video_embeds = self.visual_encoder(video)
|
|
video_atts = torch.ones(
|
|
video_embeds.size()[:-1], dtype=torch.long).to(video.device)
|
|
|
|
if train:
|
|
'''
|
|
k: number of answers for each question
|
|
weights: weight for each answer
|
|
'''
|
|
answer_targets = answer.input_ids.masked_fill(
|
|
answer.input_ids == self.tokenizer.pad_token_id, -100)
|
|
text_output = self.text_encoder(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
fusion_output = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=video_embeds,
|
|
encoder_attention_mask=video_atts,
|
|
return_dict=False)
|
|
|
|
video_output, question_output = fusion_output
|
|
|
|
question_output = torch.cat([video_output, question_output], 1)
|
|
merge_text_attention = torch.cat(
|
|
[video_atts, question.attention_mask], 1)
|
|
|
|
if k is None:
|
|
k = [1] * question_output.shape[0]
|
|
question_states = []
|
|
question_atts = []
|
|
for b, n in enumerate(k):
|
|
question_states += [question_output[b]] * n
|
|
question_atts += [merge_text_attention[b]] * n
|
|
question_states = torch.stack(question_states, 0)
|
|
question_atts = torch.stack(question_atts, 0)
|
|
|
|
if self.distill:
|
|
with torch.no_grad():
|
|
self._momentum_update()
|
|
video_embeds_m = self.visual_encoder_m(video)
|
|
text_output_m = self.text_encoder_m(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds_m = text_output_m.last_hidden_state
|
|
fusion_output_m = self.fusion_encoder_m(
|
|
encoder_embeds=text_embeds_m,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=video_embeds_m,
|
|
encoder_attention_mask=video_atts,
|
|
return_dict=False)
|
|
|
|
image_output_m, question_output_m = fusion_output_m
|
|
question_output_m = torch.cat(
|
|
[image_output_m, question_output_m], 1)
|
|
|
|
question_states_m = []
|
|
for b, n in enumerate(k):
|
|
question_states_m += [question_output_m[b]] * n
|
|
question_states_m = torch.stack(question_states_m, 0)
|
|
|
|
logits_m = self.text_decoder_m(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=question_states_m,
|
|
encoder_attention_mask=question_atts,
|
|
return_logits=True,
|
|
)
|
|
|
|
answer_output = self.text_decoder(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=question_states,
|
|
encoder_attention_mask=question_atts,
|
|
labels=answer_targets,
|
|
return_dict=True,
|
|
soft_labels=F.softmax(logits_m, dim=-1),
|
|
reduction='none',
|
|
)
|
|
else:
|
|
answer_output = self.text_decoder(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=question_states,
|
|
encoder_attention_mask=question_atts,
|
|
labels=answer_targets,
|
|
return_dict=True,
|
|
reduction='none',
|
|
)
|
|
if weights is None:
|
|
weights = 1
|
|
loss = weights * answer_output.loss
|
|
loss = loss.sum() / video.size(0)
|
|
|
|
return loss
|
|
|
|
else:
|
|
text_output = self.text_encoder(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
fusion_output = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=video_embeds,
|
|
encoder_attention_mask=video_atts,
|
|
return_dict=False)
|
|
video_output, question_output = fusion_output
|
|
question_output = torch.cat([video_output, question_output], 1)
|
|
merge_text_attention = torch.cat(
|
|
[video_atts, question.attention_mask], 1)
|
|
topk_ids, topk_probs = self.generation(question_output,
|
|
merge_text_attention)
|
|
return topk_ids, topk_probs
|
|
|
|
|
|
class HiTeAForVideoCaption(HiTeA):
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.text_decoder = BertPrefixModel(self.config_decoder)
|
|
self.beam_generator = TextGenerator(config, self.text_decoder)
|
|
|
|
def beam_search(self,
|
|
video,
|
|
question,
|
|
answer=None,
|
|
train=True,
|
|
out_size=5):
|
|
video_embeds = self.visual_encoder(video)
|
|
video_atts = torch.ones(
|
|
video_embeds.size()[:-1], dtype=torch.long).to(video.device)
|
|
text_output = self.text_encoder(
|
|
question.input_ids,
|
|
attention_mask=question.attention_mask,
|
|
return_dict=True)
|
|
text_embeds = text_output.last_hidden_state
|
|
fusion_output = self.fusion_encoder(
|
|
encoder_embeds=text_embeds,
|
|
attention_mask=question.attention_mask,
|
|
encoder_hidden_states=video_embeds,
|
|
encoder_attention_mask=video_atts,
|
|
return_dict=False)
|
|
video_output, question_output = fusion_output
|
|
question_output = torch.cat([video_output, question_output], 1)
|
|
merge_text_attention = torch.cat([video_atts, question.attention_mask],
|
|
1)
|
|
topk_ids, topk_probs = self.generation(
|
|
question_output, merge_text_attention, out_size=out_size)
|
|
return topk_ids, topk_probs
|
|
|
|
def forward(self,
|
|
video,
|
|
question,
|
|
answer=None,
|
|
train=True,
|
|
out_size=5,
|
|
scst=False):
|
|
if (scst):
|
|
return self.beam_search(
|
|
video, question, answer, train=True, out_size=out_size)
|
|
video = video.to(dtype=next(self.parameters()).dtype)
|
|
video_embeds = self.visual_encoder(video)
|
|
video_atts = torch.ones(
|
|
video_embeds.size()[:-1], dtype=torch.long).to(video.device)
|
|
|
|
if train:
|
|
answer_targets = answer.input_ids.masked_fill(
|
|
answer.input_ids == self.tokenizer.pad_token_id, -100)
|
|
answer_output = self.text_decoder(
|
|
answer.input_ids,
|
|
attention_mask=answer.attention_mask,
|
|
encoder_hidden_states=video_embeds,
|
|
encoder_attention_mask=video_atts,
|
|
labels=answer_targets,
|
|
return_dict=True,
|
|
reduction='none')
|
|
loss = answer_output.loss
|
|
|
|
return loss
|
|
else:
|
|
topk_ids, topk_probs = self.generation(video_embeds, video_atts)
|
|
return topk_ids, topk_probs
|