changed masking

src/dataset/dataset.py

@@ -37,11 +37,14 @@ class BERTDataset(Dataset):
         segment_label = ([1 for _ in range(len(t1))] + [2 for _ in range(len(t2))])[:self.seq_len]
         bert_input = (t1 + t2)[:self.seq_len]
         bert_label = (t1_label + t2_label)[:self.seq_len]
+        input_mask = ([True for _ in range(len(bert_input))])[:self.seq_len]
 
         padding = [self.tokenizer.pad_index for _ in range(self.seq_len - len(bert_input))]
+        padding_mask = [False for _ in range(self.seq_len - len(bert_input))]
         bert_input.extend(padding)
         bert_label.extend(padding)
         segment_label.extend(padding)
+        input_mask.extend(padding_mask)
 
         output = {"bert_input": bert_input,
                   "bert_label": bert_label,

src/main.py

@@ -58,7 +58,7 @@ def train():
         if test_dataset is not None else None
 
     print("Building BERT model")
-    bert = BERT(vocab_size, hidden=args.hidden, n_layers=args.layers, attn_heads=args.attn_heads)
+    bert = BERT(vocab_size, tokenizer.pad_index, hidden=args.hidden, n_layers=args.layers, attn_heads=args.attn_heads)
 
     print("Creating BERT Trainer")
     trainer = BERTTrainer(bert, vocab_size, train_dataloader=train_data_loader, test_dataloader=test_data_loader,

src/model/bert.py

@@ -10,7 +10,7 @@ class BERT(nn.Module):
     BERT model : Bidirectional Encoder Representations from Transformers.
     """
 
-    def __init__(self, vocab_size, hidden=768, n_layers=12, attn_heads=12, dropout=0.1):
+    def __init__(self, vocab_size, pad_index, hidden=768, n_layers=12, attn_heads=12, dropout=0.1):
         """
         :param vocab_size: vocab_size of total words
         :param hidden: BERT model hidden size
@@ -23,6 +23,7 @@ class BERT(nn.Module):
         self.hidden = hidden
         self.n_layers = n_layers
         self.attn_heads = attn_heads
+        self.pad_index = pad_index
 
         # paper noted they used 4*hidden_size for ff_network_hidden_size
         self.feed_forward_hidden = hidden * 4
@@ -41,16 +42,23 @@ class BERT(nn.Module):
         mask = mask.float().masked_fill(mask == 0, float('-inf')).masked_fill(mask == 1, float(0.0))
         return mask
     
+    def make_src_mask(self, src):
+        return src.transpose(0, 1) == self.pad_index
+        
+
     def forward(self, x, segment_info, has_mask=True):
-        if has_mask:
-            if self.src_mask is None or self.src_mask.size(0) != len(x):
-                mask = self._generate_square_subsequent_mask(len(x))
-                self.src_mask = mask
-        else:
-            self.src_mask = None
+        # self.src_mask = mask
+        # if has_mask:
+        #     if self.src_mask is None or self.src_mask.size(0) != len(x):
+        #         mask = self._generate_square_subsequent_mask(len(x))
+        #         self.src_mask = mask
+        # else:
+        #     self.src_mask = None
+
+        self.src_mask = self.make_src_mask(x)
 
         # embedding the indexed sequence to sequence of vectors
         x = self.embedding(x, segment_info)
-        x = self.transformer_encoder(x, self.src_mask)
+        x = self.transformer_encoder(x, src_key_padding_mask=self.src_mask)
 
         return x