TF generate refactor - Beam Search (#16374)

* refactor TF beam search

* refactored generate can now properly use attention masks

* add force bos/eos logit processors
This commit is contained in:
Joao Gante
2022-04-06 18:19:34 +01:00
committed by GitHub
parent 4d10083539
commit 3f43d824b9
11 changed files with 796 additions and 56 deletions

View File

@@ -26,6 +26,8 @@ if is_tf_available():
import tensorflow as tf
from transformers.generation_tf_logits_process import (
TFForcedBOSTokenLogitsProcessor,
TFForcedEOSTokenLogitsProcessor,
TFLogitsProcessorList,
TFMinLengthLogitsProcessor,
TFNoBadWordsLogitsProcessor,
@@ -43,7 +45,7 @@ if is_tf_available():
@require_tf
class TFLogitsProcessorTest(unittest.TestCase):
def _get_uniform_logits(self, batch_size: int, length: int):
scores = np.ones((batch_size, length), dtype=np.float32) / length
scores = tf.ones((batch_size, length), dtype=tf.float32) / length
return scores
def test_min_length_dist_processor(self):
@@ -54,15 +56,17 @@ class TFLogitsProcessorTest(unittest.TestCase):
min_dist_processor = TFMinLengthLogitsProcessor(min_length=10, eos_token_id=eos_token_id)
# check that min length is applied at length 5
input_ids = ids_tensor((batch_size, 5), vocab_size=20)
cur_len = 5
input_ids = ids_tensor((batch_size, cur_len), vocab_size=20)
scores = self._get_uniform_logits(batch_size, vocab_size)
scores_before_min_length = min_dist_processor(input_ids, scores)
scores_before_min_length = min_dist_processor(input_ids, scores, cur_len)
self.assertListEqual(scores_before_min_length[:, eos_token_id].numpy().tolist(), 4 * [-float("inf")])
# check that min length is not applied anymore at length 15
input_ids = ids_tensor((batch_size, 15), vocab_size=20)
cur_len = 15
input_ids = ids_tensor((batch_size, cur_len), vocab_size=20)
scores = self._get_uniform_logits(batch_size, vocab_size)
scores_before_min_length = min_dist_processor(input_ids, scores)
scores_before_min_length = min_dist_processor(input_ids, scores, cur_len)
self.assertFalse(tf.math.reduce_any(tf.math.is_inf(scores_before_min_length)).numpy())
def test_temperature_dist_warper(self):
@@ -72,8 +76,10 @@ class TFLogitsProcessorTest(unittest.TestCase):
scores = self._get_uniform_logits(batch_size=2, length=length)
# tweak scores to not be uniform anymore
scores = scores.numpy()
scores[1, 5] = (1 / length) + 0.1 # peak, 1st batch
scores[1, 10] = (1 / length) - 0.4 # valley, 1st batch
scores = tf.convert_to_tensor(scores)
# compute softmax
probs = tf.nn.softmax(scores, axis=-1)
@@ -97,8 +103,11 @@ class TFLogitsProcessorTest(unittest.TestCase):
self.assertLess(tf.math.reduce_min(probs[1, :]), tf.math.reduce_min(warped_prob_smooth[1, :]))
def test_repetition_penalty_dist_process(self):
input_ids = tf.constant([[0, 1], [5, 0]], dtype=tf.int32)
vocab_size = 10
cur_len = 2
input_ids = tf.constant([[0, 1], [5, 0]], dtype=tf.int32)
self.assertEqual(cur_len, input_ids.shape[1])
scores = self._get_uniform_logits(batch_size=2, length=vocab_size)
@@ -109,7 +118,7 @@ class TFLogitsProcessorTest(unittest.TestCase):
rep_penalty_proc = TFRepetitionPenaltyLogitsProcessor(penalty=2.0)
scores = rep_penalty_proc(input_ids, tf.identity(scores))
scores = rep_penalty_proc(input_ids, tf.identity(scores), cur_len)
# check that values were correctly changed
self.assertAlmostEqual(scores[0, 0].numpy(), -(1 / vocab_size) * 2)
@@ -188,15 +197,18 @@ class TFLogitsProcessorTest(unittest.TestCase):
def test_no_repeat_ngram_dist_processor(self):
vocab_size = 3
batch_size = 2
cur_len = 4
input_ids = tf.constant([[1, 1, 2, 1], [0, 1, 0, 1]], dtype=tf.int32)
self.assertEqual(cur_len, input_ids.shape[1])
scores = self._get_uniform_logits(batch_size, vocab_size)
no_repeat_proc_2_gram = TFNoRepeatNGramLogitsProcessor(2)
no_repeat_proc_3_gram = TFNoRepeatNGramLogitsProcessor(3)
filtered_scores_2_gram = no_repeat_proc_2_gram(input_ids, tf.identity(scores))
filtered_scores_3_gram = no_repeat_proc_3_gram(input_ids, tf.identity(scores))
filtered_scores_2_gram = no_repeat_proc_2_gram(input_ids, tf.identity(scores), cur_len)
filtered_scores_3_gram = no_repeat_proc_3_gram(input_ids, tf.identity(scores), cur_len)
# 2-gram would forbid 2nd and 3rd token (1,2) at 1st batch and 1st token (0) at 2nd batch
self.assertListEqual(
@@ -212,14 +224,17 @@ class TFLogitsProcessorTest(unittest.TestCase):
vocab_size = 5
batch_size = 2
eos_token_id = 4
cur_len = 4
input_ids = tf.constant([[0, 1, 3, 1], [0, 1, 0, 1]], dtype=tf.int32)
self.assertEqual(cur_len, input_ids.shape[1])
bad_word_tokens = [[1], [4], [1, 0], [0, 1, 2], [1, 3, 1, 3]]
scores = self._get_uniform_logits(batch_size, vocab_size)
no_bad_words_dist_proc = TFNoBadWordsLogitsProcessor(bad_words_ids=bad_word_tokens, eos_token_id=eos_token_id)
filtered_scores = no_bad_words_dist_proc(input_ids, tf.identity(scores))
filtered_scores = no_bad_words_dist_proc(input_ids, tf.identity(scores), cur_len)
# batch 1: 1st, 2nd, and 4th (0, 1, 3) token are forbidden
# batch 2: 1st, 2nd, and 3rd (0, 1, 2) token are forbidden
@@ -228,14 +243,65 @@ class TFLogitsProcessorTest(unittest.TestCase):
[[True, True, False, True, True], [True, True, True, False, True]],
)
def test_forced_bos_token_logits_processor(self):
vocab_size = 20
batch_size = 4
bos_token_id = 0
logits_processor = TFForcedBOSTokenLogitsProcessor(bos_token_id=bos_token_id)
# check that all scores are -inf except the bos_token_id score
cur_len = 1
input_ids = ids_tensor((batch_size, cur_len), vocab_size=20)
scores = self._get_uniform_logits(batch_size, vocab_size)
scores = logits_processor(input_ids, scores, cur_len)
self.assertTrue(
tf.math.reduce_all(tf.math.is_inf(scores[:, bos_token_id + 1 :]) & (scores[:, bos_token_id + 1 :] < 0))
)
self.assertListEqual(scores[:, bos_token_id].numpy().tolist(), 4 * [0]) # score for bos_token_id shold be zero
# check that bos_token_id is not forced if current length is greater than 1
cur_len = 4
input_ids = ids_tensor((batch_size, cur_len), vocab_size=20)
scores = self._get_uniform_logits(batch_size, vocab_size)
scores = logits_processor(input_ids, scores, cur_len)
self.assertFalse(tf.math.reduce_any(tf.math.is_inf((scores))))
def test_forced_eos_token_logits_processor(self):
vocab_size = 20
batch_size = 4
eos_token_id = 0
max_length = 5
logits_processor = TFForcedEOSTokenLogitsProcessor(max_length=max_length, eos_token_id=eos_token_id)
# check that all scores are -inf except the eos_token_id when max_length-1 is reached
cur_len = 4
input_ids = ids_tensor((batch_size, cur_len), vocab_size=20)
scores = self._get_uniform_logits(batch_size, vocab_size)
scores = logits_processor(input_ids, scores, cur_len)
self.assertTrue(
tf.math.reduce_all(tf.math.is_inf(scores[:, eos_token_id + 1 :]) & (scores[:, eos_token_id + 1 :] < 0))
)
self.assertListEqual(
scores[:, eos_token_id].numpy().tolist(), 4 * [0]
) # score for eos_token_id should be zero
# check that eos_token_id is not forced if max_length-1 is not reached
cur_len = 3
input_ids = ids_tensor((batch_size, cur_len), vocab_size=20)
scores = self._get_uniform_logits(batch_size, vocab_size)
scores = logits_processor(input_ids, scores, cur_len)
self.assertFalse(tf.math.reduce_any(tf.math.is_inf((scores))))
def test_processor_list(self):
batch_size = 4
sequence_length = 10
cur_len = 10
vocab_size = 15
eos_token_id = 0
# dummy input_ids and scores
input_ids = ids_tensor((batch_size, sequence_length), vocab_size)
input_ids = ids_tensor((batch_size, cur_len), vocab_size)
input_ids_comp = tf.identity(input_ids)
scores = self._get_uniform_logits(batch_size, vocab_size)
@@ -251,13 +317,13 @@ class TFLogitsProcessorTest(unittest.TestCase):
no_bad_words_dist_proc = TFNoBadWordsLogitsProcessor(bad_words_ids=[[1]], eos_token_id=eos_token_id)
# no processor list
scores = min_dist_proc(input_ids, scores)
scores = min_dist_proc(input_ids, scores, cur_len)
scores = temp_dist_warp(input_ids, scores)
scores = rep_penalty_proc(input_ids, scores)
scores = rep_penalty_proc(input_ids, scores, cur_len)
scores = top_k_warp(input_ids, scores)
scores = top_p_warp(input_ids, scores)
scores = no_repeat_proc(input_ids, scores)
scores = no_bad_words_dist_proc(input_ids, scores)
scores = no_repeat_proc(input_ids, scores, cur_len)
scores = no_bad_words_dist_proc(input_ids, scores, cur_len)
# with processor list
processor = TFLogitsProcessorList(
@@ -271,7 +337,7 @@ class TFLogitsProcessorTest(unittest.TestCase):
no_bad_words_dist_proc,
]
)
scores_comp = processor(input_ids, scores_comp)
scores_comp = processor(input_ids, scores_comp, cur_len=cur_len)
# remove inf
scores = set_tensor_by_indices_to_value(scores, tf.math.is_inf(scores), -1e9)