File size: 10,784 Bytes
4cda815
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
# -*- coding: utf-8 -*-
# @Time    : 2022/4/21 5:30 下午
# @Author  : JianingWang
# @File    : fusion_siamese.py
from typing import Optional
import torch
import numpy as np
import torch.nn as nn
from dataclasses import dataclass
from torch.nn import BCEWithLogitsLoss
from transformers import MegatronBertModel, MegatronBertPreTrainedModel
from transformers.file_utils import ModelOutput
from transformers.models.bert import BertPreTrainedModel, BertModel
from transformers.activations import ACT2FN
from torch.nn import CrossEntropyLoss, MSELoss, BCEWithLogitsLoss
from transformers.modeling_outputs import SequenceClassifierOutput
from loss.focal_loss import FocalLoss
# from roformer import RoFormerPreTrainedModel, RoFormerModel


class BertPooler(nn.Module):
    def __init__(self, hidden_size, hidden_act):
        super().__init__()
        self.dense = nn.Linear(hidden_size, hidden_size)
        # self.activation = nn.Tanh()
        self.activation = ACT2FN[hidden_act]
        # self.dropout = nn.Dropout(hidden_dropout_prob)

    def forward(self, features):
        x = features[:, 0, :]  # take <s> token (equiv. to [CLS])
        # x = self.dropout(x)
        x = self.dense(x)
        x = self.activation(x)
        return x


class BertForFusionSiamese(BertPreTrainedModel):
    def __init__(self, config):
        super().__init__(config)
        self.num_labels = config.num_labels
        self.bert = BertModel(config)
        self.hidden_size = config.hidden_size
        self.hidden_act = config.hidden_act
        self.bert_poor = BertPooler(self.hidden_size, self.hidden_act)
        self.dense_1 = nn.Linear(self.hidden_size, self.hidden_size)
        self.dense_2 = nn.Linear(self.hidden_size, self.hidden_size)

        if hasattr(config, "cls_dropout_rate"):
            cls_dropout_rate = config.cls_dropout_rate
        else:
            cls_dropout_rate = config.hidden_dropout_prob
        self.dropout = nn.Dropout(cls_dropout_rate)
        self.classifier = nn.Linear(3 * self.hidden_size, config.num_labels)
        self.init_weights()

    def forward(
            self,
            input_ids=None,
            attention_mask=None,
            token_type_ids=None,
            position_ids=None,
            head_mask=None,
            inputs_embeds=None,
            labels=None,
            output_attentions=None,
            output_hidden_states=None,
            return_dict=None,
            pseudo_label=None,
            segment_spans=None,
            pseuso_proba=None
    ):
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
        logits, outputs = None, None
        inputs = {"input_ids": input_ids, "attention_mask": attention_mask, "token_type_ids": token_type_ids,
                  "position_ids": position_ids,
                  "head_mask": head_mask, "inputs_embeds": inputs_embeds, "output_attentions": output_attentions,
                  "output_hidden_states": output_hidden_states, "return_dict": return_dict}
        inputs = {k: v for k, v in inputs.items() if v is not None}
        outputs = self.bert(**inputs)
        if "sequence_output" in outputs:
            sequence_output = outputs.sequence_output # [bz, seq_len, dim]
        else:
            sequence_output = outputs[0] # [bz, seq_len, dim]

        cls_output = self.bert_poor(sequence_output) # [bz, dim]

        if segment_spans is not None:
            # 如果输入的是两个segment,则分别进行平均池化
            seg1_embeddings, seg2_embeddings = list(), list()
            for ei, sentence_embeddings in enumerate(sequence_output):
                # sentence_embedding: [seq_len, dim]
                seg1_start, seg1_end, seg2_start, seg2_end = segment_spans[ei]
                # print("sentence_embeddings[seg1_start, seg1_end].shape=", sentence_embeddings[seg1_start, seg1_end].shape)
                # print("torch.mean(sentence_embeddings[seg1_start, seg1_end], 0).shape=", torch.mean(sentence_embeddings[seg1_start, seg1_end], 0).shape)
                seg1_embeddings.append(torch.mean(sentence_embeddings[seg1_start: seg1_end], 0)) # [dim]
                seg2_embeddings.append(torch.mean(sentence_embeddings[seg2_start: seg2_end], 0)) # [dim]
            seg1_embeddings, seg2_embeddings = torch.stack(seg1_embeddings), torch.stack(seg2_embeddings) # [bz, dim]
            # print("seg1_embeddings.shape=", seg1_embeddings.shape)
            seg1_embeddings = self.bert_poor.activation(self.dense_1(seg1_embeddings))
            seg2_embeddings = self.bert_poor.activation(self.dense_1(seg2_embeddings))
            cls_output = torch.cat([cls_output, seg1_embeddings, seg2_embeddings], dim=-1) # [bz, 3*dim]
            # cls_output = cls_output + seg1_embeddings + seg2_embeddings # [bz, dim]

        pooler_output = self.dropout(cls_output)
        # pooler_output = self.LayerNorm(pooler_output)
        logits = self.classifier(pooler_output)

        loss = None
        if labels is not None:

            # loss_fct = FocalLoss()
            loss_fct = CrossEntropyLoss()
            # 伪标签
            if pseudo_label is not None:
                train_logits, pseudo_logits = logits[pseudo_label > 0.9], logits[pseudo_label < 0.1]
                train_labels, pseudo_labels = labels[pseudo_label > 0.9], labels[pseudo_label < 0.1]
                train_loss = loss_fct(train_logits.view(-1, self.num_labels),
                                      train_labels.view(-1)) if train_labels.nelement() else 0
                pseudo_loss = loss_fct(pseudo_logits.view(-1, self.num_labels),
                                       pseudo_labels.view(-1)) if pseudo_labels.nelement() else 0
                loss = 0.9 * train_loss + 0.1 * pseudo_loss
            else:
                loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
        return SequenceClassifierOutput(
            loss=loss,
            logits=logits,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )



class BertForWSC(BertPreTrainedModel):
    def __init__(self, config):
        super().__init__(config)
        self.num_labels = config.num_labels
        self.bert = BertModel(config)
        self.hidden_size = config.hidden_size
        self.hidden_act = config.hidden_act
        self.bert_poor = BertPooler(self.hidden_size, self.hidden_act)
        self.dense_1 = nn.Linear(self.hidden_size, self.hidden_size)
        self.dense_2 = nn.Linear(self.hidden_size, self.hidden_size)

        if hasattr(config, "cls_dropout_rate"):
            cls_dropout_rate = config.cls_dropout_rate
        else:
            cls_dropout_rate = config.hidden_dropout_prob
        self.dropout = nn.Dropout(cls_dropout_rate)
        self.classifier = nn.Linear(2 * self.hidden_size, config.num_labels)
        self.init_weights()

    def forward(
            self,
            input_ids=None,
            attention_mask=None,
            token_type_ids=None,
            position_ids=None,
            head_mask=None,
            inputs_embeds=None,
            labels=None,
            output_attentions=None,
            output_hidden_states=None,
            return_dict=None,
            pseudo_label=None,
            span=None,
            pseuso_proba=None
    ):
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
        logits, outputs = None, None
        inputs = {"input_ids": input_ids, "attention_mask": attention_mask, "token_type_ids": token_type_ids,
                  "position_ids": position_ids,
                  "head_mask": head_mask, "inputs_embeds": inputs_embeds, "output_attentions": output_attentions,
                  "output_hidden_states": output_hidden_states, "return_dict": return_dict}
        inputs = {k: v for k, v in inputs.items() if v is not None}
        outputs = self.bert(**inputs)
        if "sequence_output" in outputs:
            sequence_output = outputs.sequence_output # [bz, seq_len, dim]
        else:
            sequence_output = outputs[0] # [bz, seq_len, dim]

        # cls_output = self.bert_poor(sequence_output) # [bz, dim]

        # 如果输入的是两个span,则分别进行平均池化
        seg1_embeddings, seg2_embeddings = list(), list()
        # print("span=", span)
        for ei, sentence_embeddings in enumerate(sequence_output):
            # sentence_embedding: [seq_len, dim]
            seg1_start, seg1_end, seg2_start, seg2_end = span[ei]
            # print("sentence_embeddings[seg1_start, seg1_end].shape=", sentence_embeddings[seg1_start, seg1_end].shape)
            # print("torch.mean(sentence_embeddings[seg1_start, seg1_end], 0).shape=", torch.mean(sentence_embeddings[seg1_start, seg1_end], 0).shape)
            seg1_embeddings.append(torch.mean(sentence_embeddings[seg1_start+1: seg1_end], 0)) # [dim]
            seg2_embeddings.append(torch.mean(sentence_embeddings[seg2_start+1: seg2_end], 0)) # [dim]
        seg1_embeddings, seg2_embeddings = torch.stack(seg1_embeddings), torch.stack(seg2_embeddings) # [bz, dim]
        # print("seg1_embeddings.shape=", seg1_embeddings.shape)
        # seg1_embeddings = self.bert_poor.activation(self.dense_1(seg1_embeddings))
        # seg2_embeddings = self.bert_poor.activation(self.dense_1(seg2_embeddings))
        cls_output = torch.cat([seg1_embeddings, seg2_embeddings], dim=-1) # [bz, 3*dim]
        # cls_output = cls_output + seg1_embeddings + seg2_embeddings # [bz, dim]

        pooler_output = self.dropout(cls_output)
        # pooler_output = self.LayerNorm(pooler_output)
        logits = self.classifier(pooler_output)

        loss = None
        if labels is not None:

            # loss_fct = FocalLoss()
            loss_fct = CrossEntropyLoss()
            # 伪标签
            if pseudo_label is not None:
                train_logits, pseudo_logits = logits[pseudo_label > 0.9], logits[pseudo_label < 0.1]
                train_labels, pseudo_labels = labels[pseudo_label > 0.9], labels[pseudo_label < 0.1]
                train_loss = loss_fct(train_logits.view(-1, self.num_labels),
                                      train_labels.view(-1)) if train_labels.nelement() else 0
                pseudo_loss = loss_fct(pseudo_logits.view(-1, self.num_labels),
                                       pseudo_labels.view(-1)) if pseudo_labels.nelement() else 0
                loss = 0.9 * train_loss + 0.1 * pseudo_loss
            else:
                loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
        return SequenceClassifierOutput(
            loss=loss,
            logits=logits,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )