Fix DataCollatorForWholeWordMask (huggingface#8379)

* Fix DataCollatorForWholeWordMask

* Replace all tensorize_batch in data_collator.py

Author: changjonathanc

src/transformers/data/data_collator.py

@@ -315,7 +315,7 @@ def __call__(
             input_ids = examples
             examples = [{"input_ids": e} for e in examples]
 
-        batch_input = self._tensorize_batch(input_ids)
+        batch_input = _collate_batch(input_ids, self.tokenizer)
 
         mask_labels = []
         for e in examples:
@@ -332,7 +332,7 @@ def __call__(
                     if i in ref_pos:
                         ref_tokens[i] = "##" + ref_tokens[i]
             mask_labels.append(self._whole_word_mask(ref_tokens))
-        batch_mask = self._tensorize_batch(mask_labels)
+        batch_mask = _collate_batch(mask_labels, self.tokenizer)
         inputs, labels = self.mask_tokens(batch_input, batch_mask)
         return {"input_ids": inputs, "labels": labels}
 
@@ -511,28 +511,10 @@ def __call__(
     ) -> Dict[str, torch.Tensor]:
         if isinstance(examples[0], (dict, BatchEncoding)):
             examples = [e["input_ids"] for e in examples]
-        batch = self._tensorize_batch(examples)
+        batch = _collate_batch(examples, self.tokenizer)
         inputs, perm_mask, target_mapping, labels = self.mask_tokens(batch)
         return {"input_ids": inputs, "perm_mask": perm_mask, "target_mapping": target_mapping, "labels": labels}
 
-    def _tensorize_batch(
-        self, examples: List[Union[List[int], torch.Tensor, Dict[str, torch.Tensor]]]
-    ) -> torch.Tensor:
-        # In order to accept both lists of lists and lists of Tensors
-        if isinstance(examples[0], (list, tuple)):
-            examples = [torch.Tensor(e) for e in examples]
-        length_of_first = examples[0].size(0)
-        are_tensors_same_length = all(x.size(0) == length_of_first for x in examples)
-        if are_tensors_same_length:
-            return torch.stack(examples, dim=0)
-        else:
-            if self.tokenizer._pad_token is None:
-                raise ValueError(
-                    "You are attempting to pad samples but the tokenizer you are using"
-                    f" ({self.tokenizer.__class__.__name__}) does not have one."
-                )
-            return pad_sequence(examples, batch_first=True, padding_value=self.tokenizer.pad_token_id)
-
     def mask_tokens(self, inputs: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
         """
         The masked tokens to be predicted for a particular sequence are determined by the following algorithm: