Revert sequence generator changes

fairseq/sequence_generator.py

@@ -83,10 +83,11 @@ class SequenceGenerator(object):
                 timer.start()
             with torch.no_grad():
                 hypos = self.generate(
+                    input['src_tokens'],
+                    input['src_lengths'],
                     beam_size=beam_size,
                     maxlen=int(maxlen_a*srclen + maxlen_b),
                     prefix_tokens=s['target'][:, :prefix_size] if prefix_size > 0 else None,
-                    **net_input,
                 )
             if timer is not None:
                 timer.stop(sum(len(h[0]['tokens']) for h in hypos))
@@ -96,13 +97,12 @@ class SequenceGenerator(object):
                 ref = utils.strip_pad(s['target'].data[i, :], self.pad) if s['target'] is not None else None
                 yield id, src, ref, hypos[i]
 
-    def generate(self, beam_size=None, maxlen=None, prefix_tokens=None, **net_input):
+    def generate(self, src_tokens, src_lengths, beam_size=None, maxlen=None, prefix_tokens=None):
         """Generate a batch of translations."""
         with torch.no_grad():
-            return self._generate(beam_size, maxlen, prefix_tokens, **net_input)
+            return self._generate(src_tokens, src_lengths, beam_size, maxlen, prefix_tokens)
 
-    def _generate(self, beam_size=None, maxlen=None, prefix_tokens=None, **net_input):
-        src_tokens = net_input['src_tokens']
+    def _generate(self, src_tokens, src_lengths, beam_size=None, maxlen=None, prefix_tokens=None):
         bsz, srclen = src_tokens.size()
         maxlen = min(maxlen, self.maxlen) if maxlen is not None else self.maxlen
 
@@ -121,10 +121,10 @@ class SequenceGenerator(object):
                 incremental_states[model] = None
 
             # compute the encoder output for each beam
-            encoder_out = model.encoder(**net_input)
-            new_order = torch.arange(bsz).view(-1, 1).repeat(1, beam_size).view(-1)
-            new_order = new_order.to(net_input['src_tokens'].device)
-            encoder_out = model.encoder.reorder_encoder_out(encoder_out, new_order)
+            encoder_out = model.encoder(
+                src_tokens.repeat(1, beam_size).view(-1, srclen),
+                src_lengths.expand(beam_size, src_lengths.numel()).t().contiguous().view(-1),
+            )
             encoder_outs.append(encoder_out)
 
         # initialize buffers

tests/test_sequence_generator.py

@@ -85,7 +85,7 @@ class TestSequenceGenerator(unittest.TestCase):
 
     def test_with_normalization(self):
         generator = SequenceGenerator([self.model], self.tgt_dict)
-        hypos = generator.generate(src_tokens=self.src_tokens, src_lengths=self.src_lengths, beam_size=2)
+        hypos = generator.generate(self.src_tokens, self.src_lengths, beam_size=2)
         eos, w1, w2 = self.eos, self.w1, self.w2
         # sentence 1, beam 1
         self.assertHypoTokens(hypos[0][0], [w1, eos])
@@ -104,7 +104,7 @@ class TestSequenceGenerator(unittest.TestCase):
         # Sentence 1: unchanged from the normalized case
         # Sentence 2: beams swap order
         generator = SequenceGenerator([self.model], self.tgt_dict, normalize_scores=False)
-        hypos = generator.generate(src_tokens=self.src_tokens, src_lengths=self.src_lengths, beam_size=2)
+        hypos = generator.generate(self.src_tokens, self.src_lengths, beam_size=2)
         eos, w1, w2 = self.eos, self.w1, self.w2
         # sentence 1, beam 1
         self.assertHypoTokens(hypos[0][0], [w1, eos])
@@ -122,7 +122,7 @@ class TestSequenceGenerator(unittest.TestCase):
     def test_with_lenpen_favoring_short_hypos(self):
         lenpen = 0.6
         generator = SequenceGenerator([self.model], self.tgt_dict, len_penalty=lenpen)
-        hypos = generator.generate(src_tokens=self.src_tokens, src_lengths=self.src_lengths, beam_size=2)
+        hypos = generator.generate(self.src_tokens, self.src_lengths, beam_size=2)
         eos, w1, w2 = self.eos, self.w1, self.w2
         # sentence 1, beam 1
         self.assertHypoTokens(hypos[0][0], [w1, eos])
@@ -140,7 +140,7 @@ class TestSequenceGenerator(unittest.TestCase):
     def test_with_lenpen_favoring_long_hypos(self):
         lenpen = 5.0
         generator = SequenceGenerator([self.model], self.tgt_dict, len_penalty=lenpen)
-        hypos = generator.generate(src_tokens=self.src_tokens, src_lengths=self.src_lengths, beam_size=2)
+        hypos = generator.generate(self.src_tokens, self.src_lengths, beam_size=2)
         eos, w1, w2 = self.eos, self.w1, self.w2
         # sentence 1, beam 1
         self.assertHypoTokens(hypos[0][0], [w2, w1, w2, eos])
@@ -157,7 +157,7 @@ class TestSequenceGenerator(unittest.TestCase):
 
     def test_maxlen(self):
         generator = SequenceGenerator([self.model], self.tgt_dict, maxlen=2)
-        hypos = generator.generate(src_tokens=self.src_tokens, src_lengths=self.src_lengths, beam_size=2)
+        hypos = generator.generate(self.src_tokens, self.src_lengths, beam_size=2)
         eos, w1, w2 = self.eos, self.w1, self.w2
         # sentence 1, beam 1
         self.assertHypoTokens(hypos[0][0], [w1, eos])
@@ -174,7 +174,7 @@ class TestSequenceGenerator(unittest.TestCase):
 
     def test_no_stop_early(self):
         generator = SequenceGenerator([self.model], self.tgt_dict, stop_early=False)
-        hypos = generator.generate(src_tokens=self.src_tokens, src_lengths=self.src_lengths, beam_size=2)
+        hypos = generator.generate(self.src_tokens, self.src_lengths, beam_size=2)
         eos, w1, w2 = self.eos, self.w1, self.w2
         # sentence 1, beam 1
         self.assertHypoTokens(hypos[0][0], [w1, eos])