Temporarily revert the `fill-mask` improvements.

src/transformers/pipelines/fill_mask.py

@@ -98,9 +98,9 @@ class FillMaskPipeline(Pipeline):
             args (:obj:`str` or :obj:`List[str]`):
                 One or several texts (or one list of prompts) with masked tokens.
             targets (:obj:`str` or :obj:`List[str]`, `optional`):
-                When passed, the model will limit the scores to the passed targets instead of looking up in the whole
-                vocab. If the provided targets are not in the model vocab, they will be tokenized and the first
-                resulting token will be used (with a warning, and that might be slower).
+                When passed, the model will return the scores for the passed token or tokens rather than the top k
+                predictions in the entire vocabulary. If the provided targets are not in the model vocab, they will be
+                tokenized and the first resulting token will be used (with a warning).
             top_k (:obj:`int`, `optional`):
                 When passed, overrides the number of predictions to return.
 
@@ -115,56 +115,25 @@ class FillMaskPipeline(Pipeline):
         inputs = self._parse_and_tokenize(*args, **kwargs)
         outputs = self._forward(inputs, return_tensors=True)
 
-        # top_k must be defined
-        if top_k is None:
-            top_k = self.top_k
-
         results = []
         batch_size = outputs.shape[0] if self.framework == "tf" else outputs.size(0)
 
         if targets is not None:
+            if len(targets) == 0 or len(targets[0]) == 0:
+                raise ValueError("At least one target must be provided when passed.")
             if isinstance(targets, str):
                 targets = [targets]
 
-            try:
-                vocab = self.tokenizer.get_vocab()
-            except Exception:
-                vocab = {}
-            target_ids = []
+            targets_proc = []
             for target in targets:
-                id_ = vocab.get(target, None)
-                if id_ is None:
-                    input_ids = self.tokenizer(
-                        target,
-                        add_special_tokens=False,
-                        return_attention_mask=False,
-                        return_token_type_ids=False,
-                        max_length=1,
-                        truncation=True,
-                    )["input_ids"]
-                    if len(input_ids) == 0:
-                        logger.warning(
-                            f"The specified target token `{target}` does not exist in the model vocabulary. "
-                            f"We cannot replace it with anything meaningful, ignoring it"
-                        )
-                        continue
-                    id_ = input_ids[0]
-                    # XXX: If users encounter this pass
-                    # it becomes pretty slow, so let's make sure
-                    # The warning enables them to fix the input to
-                    # get faster performance.
+                target_enc = self.tokenizer.tokenize(target)
+                if len(target_enc) > 1 or target_enc[0] == self.tokenizer.unk_token:
                     logger.warning(
                         f"The specified target token `{target}` does not exist in the model vocabulary. "
-                        f"Replacing with `{self.tokenizer.convert_ids_to_tokens(id_)}`."
+                        f"Replacing with `{target_enc[0]}`."
                     )
-                target_ids.append(id_)
-            target_ids = list(set(target_ids))
-            if len(target_ids) == 0:
-                raise ValueError("At least one target must be provided when passed.")
-            target_ids = np.array(target_ids)
-            # Cap top_k if there are targets
-            if top_k > target_ids.shape[0]:
-                top_k = target_ids.shape[0]
+                targets_proc.append(target_enc[0])
+            target_inds = np.array(self.tokenizer.convert_tokens_to_ids(targets_proc))
 
         for i in range(batch_size):
             input_ids = inputs["input_ids"][i]
@@ -178,11 +147,14 @@ class FillMaskPipeline(Pipeline):
 
                 logits = outputs[i, masked_index.item(), :]
                 probs = tf.nn.softmax(logits)
-                if targets is not None:
-                    probs = tf.gather_nd(probs, tf.reshape(target_ids, (-1, 1)))
-
-                topk = tf.math.top_k(probs, k=top_k)
-                values, predictions = topk.values.numpy(), topk.indices.numpy()
+                if targets is None:
+                    topk = tf.math.top_k(probs, k=top_k if top_k is not None else self.top_k)
+                    values, predictions = topk.values.numpy(), topk.indices.numpy()
+                else:
+                    values = tf.gather_nd(probs, tf.reshape(target_inds, (-1, 1)))
+                    sort_inds = tf.reverse(tf.argsort(values), [0])
+                    values = tf.gather_nd(values, tf.reshape(sort_inds, (-1, 1))).numpy()
+                    predictions = target_inds[sort_inds.numpy()]
             else:
                 masked_index = torch.nonzero(input_ids == self.tokenizer.mask_token_id, as_tuple=False)
 
@@ -191,11 +163,13 @@ class FillMaskPipeline(Pipeline):
 
                 logits = outputs[i, masked_index.item(), :]
                 probs = logits.softmax(dim=0)
-
-                if targets is not None:
-                    probs = probs[..., target_ids]
-
-                values, predictions = probs.topk(top_k)
+                if targets is None:
+                    values, predictions = probs.topk(top_k if top_k is not None else self.top_k)
+                else:
+                    values = probs[..., target_inds]
+                    sort_inds = list(reversed(values.argsort(dim=-1)))
+                    values = values[..., sort_inds]
+                    predictions = target_inds[sort_inds]
 
             for v, p in zip(values.tolist(), predictions.tolist()):
                 tokens = input_ids.numpy()

tests/test_pipelines_fill_mask.py

@@ -78,8 +78,7 @@ class FillMaskPipelineTests(MonoInputPipelineCommonMixin, unittest.TestCase):
     @require_torch
     def test_torch_fill_mask_with_targets(self):
         valid_inputs = ["My name is <mask>"]
-        # ' Sam' will yield a warning but work
-        valid_targets = [[" Teven", "ĠPatrick", "ĠClara"], ["ĠSam"], [" Sam"]]
+        valid_targets = [[" Teven", " Patrick", " Clara"], [" Sam"]]
         invalid_targets = [[], [""], ""]
         for model_name in self.small_models:
             unmasker = pipeline(task="fill-mask", model=model_name, tokenizer=model_name, framework="pt")
@@ -90,34 +89,10 @@ class FillMaskPipelineTests(MonoInputPipelineCommonMixin, unittest.TestCase):
             for targets in invalid_targets:
                 self.assertRaises(ValueError, unmasker, valid_inputs, targets=targets)
 
-    @require_torch
-    def test_torch_fill_mask_with_targets_and_topk(self):
-        model_name = self.small_models[0]
-        unmasker = pipeline(task="fill-mask", model=model_name, tokenizer=model_name, framework="pt")
-        targets = [" Teven", "ĠPatrick", "ĠClara"]
-        top_k = 2
-        outputs = unmasker("My name is <mask>", targets=targets, top_k=top_k)
-
-        self.assertEqual(len(outputs), 2)
-
-    @require_torch
-    def test_torch_fill_mask_with_duplicate_targets_and_topk(self):
-        model_name = self.small_models[0]
-        unmasker = pipeline(task="fill-mask", model=model_name, tokenizer=model_name, framework="pt")
-        # String duplicates + id duplicates
-        targets = [" Teven", "ĠPatrick", "ĠClara", "ĠClara", " Clara"]
-        top_k = 10
-        outputs = unmasker("My name is <mask>", targets=targets, top_k=top_k)
-
-        # The target list contains duplicates, so we can't output more
-        # than them
-        self.assertEqual(len(outputs), 3)
-
     @require_tf
     def test_tf_fill_mask_with_targets(self):
         valid_inputs = ["My name is <mask>"]
-        # ' Sam' will yield a warning but work
-        valid_targets = [[" Teven", "ĠPatrick", "ĠClara"], ["ĠSam"], [" Sam"]]
+        valid_targets = [[" Teven", " Patrick", " Clara"], [" Sam"]]
         invalid_targets = [[], [""], ""]
         for model_name in self.small_models:
             unmasker = pipeline(task="fill-mask", model=model_name, tokenizer=model_name, framework="tf")
@@ -136,7 +111,7 @@ class FillMaskPipelineTests(MonoInputPipelineCommonMixin, unittest.TestCase):
             "My name is <mask>",
             "The largest city in France is <mask>",
         ]
-        valid_targets = ["ĠPatrick", "ĠClara"]
+        valid_targets = [" Patrick", " Clara"]
         for model_name in self.large_models:
             unmasker = pipeline(
                 task="fill-mask",
@@ -209,7 +184,7 @@ class FillMaskPipelineTests(MonoInputPipelineCommonMixin, unittest.TestCase):
             "My name is <mask>",
             "The largest city in France is <mask>",
         ]
-        valid_targets = ["ĠPatrick", "ĠClara"]
+        valid_targets = [" Patrick", " Clara"]
         for model_name in self.large_models:
             unmasker = pipeline(task="fill-mask", model=model_name, tokenizer=model_name, framework="tf", top_k=2)