|
from typing import Tuple, Union |
|
|
|
import torch |
|
from transformers import PretrainedConfig |
|
from transformers.modeling_outputs import BaseModelOutputWithPoolingAndCrossAttentions |
|
from transformers.models.bert.modeling_bert import BertModel |
|
|
|
|
|
class GoldenRetrieverConfig(PretrainedConfig): |
|
model_type = "bert" |
|
|
|
def __init__( |
|
self, |
|
vocab_size=30522, |
|
hidden_size=768, |
|
num_hidden_layers=12, |
|
num_attention_heads=12, |
|
intermediate_size=3072, |
|
hidden_act="gelu", |
|
hidden_dropout_prob=0.1, |
|
attention_probs_dropout_prob=0.1, |
|
max_position_embeddings=512, |
|
type_vocab_size=2, |
|
initializer_range=0.02, |
|
layer_norm_eps=1e-12, |
|
pad_token_id=0, |
|
position_embedding_type="absolute", |
|
use_cache=True, |
|
classifier_dropout=None, |
|
**kwargs, |
|
): |
|
super().__init__(pad_token_id=pad_token_id, **kwargs) |
|
|
|
self.vocab_size = vocab_size |
|
self.hidden_size = hidden_size |
|
self.num_hidden_layers = num_hidden_layers |
|
self.num_attention_heads = num_attention_heads |
|
self.hidden_act = hidden_act |
|
self.intermediate_size = intermediate_size |
|
self.hidden_dropout_prob = hidden_dropout_prob |
|
self.attention_probs_dropout_prob = attention_probs_dropout_prob |
|
self.max_position_embeddings = max_position_embeddings |
|
self.type_vocab_size = type_vocab_size |
|
self.initializer_range = initializer_range |
|
self.layer_norm_eps = layer_norm_eps |
|
self.position_embedding_type = position_embedding_type |
|
self.use_cache = use_cache |
|
self.classifier_dropout = classifier_dropout |
|
|
|
|
|
class GoldenRetrieverModel(BertModel): |
|
config_class = GoldenRetrieverConfig |
|
|
|
def __init__(self, config, *args, **kwargs): |
|
super().__init__(config) |
|
self.layer_norm_layer = torch.nn.LayerNorm( |
|
config.hidden_size, eps=config.layer_norm_eps |
|
) |
|
|
|
def forward( |
|
self, **kwargs |
|
) -> Union[Tuple[torch.Tensor], BaseModelOutputWithPoolingAndCrossAttentions]: |
|
attention_mask = kwargs.get("attention_mask", None) |
|
model_outputs = super().forward(**kwargs) |
|
if attention_mask is None: |
|
pooler_output = model_outputs.pooler_output |
|
else: |
|
token_embeddings = model_outputs.last_hidden_state |
|
input_mask_expanded = ( |
|
attention_mask.unsqueeze(-1).expand(token_embeddings.size()).float() |
|
) |
|
pooler_output = torch.sum( |
|
token_embeddings * input_mask_expanded, 1 |
|
) / torch.clamp(input_mask_expanded.sum(1), min=1e-9) |
|
|
|
pooler_output = self.layer_norm_layer(pooler_output) |
|
|
|
if not kwargs.get("return_dict", True): |
|
return (model_outputs[0], pooler_output) + model_outputs[2:] |
|
|
|
return BaseModelOutputWithPoolingAndCrossAttentions( |
|
last_hidden_state=model_outputs.last_hidden_state, |
|
pooler_output=pooler_output, |
|
past_key_values=model_outputs.past_key_values, |
|
hidden_states=model_outputs.hidden_states, |
|
attentions=model_outputs.attentions, |
|
cross_attentions=model_outputs.cross_attentions, |
|
) |
|
|