388 lines
16 KiB
Python
388 lines
16 KiB
Python
# Copyright (c) 2023 PaddlePaddle Authors. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import random
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import unittest
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import paddle
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from paddle import nn
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def ids_tensor(shape, vocab_size, rng=None, name=None):
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# Creates a random int32 tensor of the shape within the vocab size
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if rng is None:
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rng = random.Random()
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total_dims = 1
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for dim in shape:
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total_dims *= dim
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values = []
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for _ in range(total_dims):
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values.append(rng.randint(0, vocab_size - 1))
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return paddle.to_tensor(data=values).reshape(shape)
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from paddlenlp.generation.logits_process import (
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ForcedBOSTokenLogitsProcessor,
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ForcedEOSTokenLogitsProcessor,
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HammingDiversityLogitsProcessor,
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LogitsProcessorList,
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MinLengthLogitsProcessor,
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NoBadWordsLogitsProcessor,
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NoRepeatNGramLogitsProcessor,
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PrefixConstrainedLogitsProcessor,
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RepetitionPenaltyLogitsProcessor,
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SequenceBiasLogitsProcessor,
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TemperatureLogitsWarper,
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TopKProcess,
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TopPProcess,
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)
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class LogitsProcessorTest(unittest.TestCase):
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def _get_uniform_logits(self, batch_size: int, length: int):
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scores = paddle.ones((batch_size, length)) / length
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return scores
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def test_min_length_dist_processor(self):
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vocab_size = 20
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batch_size = 4
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eos_token_id = 0
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min_dist_processor = MinLengthLogitsProcessor(min_length=10, eos_token_id=eos_token_id)
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# check that min length is applied at length 5
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input_ids = ids_tensor((batch_size, 5), vocab_size=20)
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores_before_min_length = min_dist_processor(input_ids, scores)
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self.assertListEqual(scores_before_min_length[:, eos_token_id].tolist(), 4 * [paddle.finfo(scores.dtype).min])
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# check that min length is not applied anymore at length 15
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input_ids = ids_tensor((batch_size, 15), vocab_size=20)
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores_before_min_length = min_dist_processor(input_ids, scores)
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self.assertFalse((scores_before_min_length == paddle.finfo(scores.dtype).min).any())
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def test_temperature_dist_warper(self):
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input_ids = None
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length = 20
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scores = self._get_uniform_logits(batch_size=2, length=length)
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# tweak scores to not be uniform anymore
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scores[1, 5] = (1 / length) + 0.1 # peak, 1st batch
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scores[1, 10] = (1 / length) - 0.4 # valley, 1st batch
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# compute softmax
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probs = nn.functional.softmax(scores, axis=-1)
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temp_dist_warper_sharper = TemperatureLogitsWarper(temperature=0.5)
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temp_dist_warper_smoother = TemperatureLogitsWarper(temperature=1.3)
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warped_prob_sharp = nn.functional.softmax(temp_dist_warper_sharper(input_ids, scores.clone()), axis=-1)
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warped_prob_smooth = nn.functional.softmax(temp_dist_warper_smoother(input_ids, scores.clone()), axis=-1)
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# uniform distribution stays uniform
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self.assertTrue(paddle.allclose(probs[0, :], warped_prob_sharp[0, :], atol=1e-3))
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self.assertTrue(paddle.allclose(probs[0, :], warped_prob_smooth[0, :], atol=1e-3))
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# sharp peaks get higher, valleys get lower
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self.assertLess(probs[1, :].max(), warped_prob_sharp[1, :].max())
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self.assertGreater(probs[1, :].min(), warped_prob_sharp[1, :].min())
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# smooth peaks get lower, valleys get higher
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self.assertGreater(probs[1, :].max(), warped_prob_smooth[1, :].max())
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self.assertLess(probs[1, :].min(), warped_prob_smooth[1, :].min())
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def test_repetition_penalty_dist_process(self):
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input_ids = paddle.to_tensor([[0, 1], [5, 0]])
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vocab_size = 10
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scores = self._get_uniform_logits(batch_size=2, length=vocab_size)
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# give values special values
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scores[0, 0] = -(1 / vocab_size)
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scores[1, 5] = 4 / vocab_size
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rep_penalty_proc = RepetitionPenaltyLogitsProcessor(penalty=2.0)
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scores = rep_penalty_proc(input_ids, scores.clone())
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# check that values were correctly changed
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self.assertAlmostEqual(scores[0, 0].item(), -(1 / vocab_size) * 2)
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self.assertAlmostEqual(scores[0, 1].item(), (1 / vocab_size) / 2)
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self.assertAlmostEqual(scores[1, 0].item(), (1 / vocab_size) / 2)
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self.assertAlmostEqual(scores[1, 5].item(), (4 / vocab_size) / 2)
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def test_top_k_dist_warper(self):
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vocab_size = 10
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batch_size = 2
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# create ramp distribution
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ramp_logits = paddle.arange(vocab_size).unsqueeze(0).tile((batch_size, 1))
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ramp_logits[1:, : vocab_size // 2] = ramp_logits[1:, : vocab_size // 2] + vocab_size
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ramp_logits = ramp_logits.astype("float32")
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scores = TopKProcess(ramp_logits, 3, 1)
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# check that correct tokens are filtered
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self.assertListEqual((scores[0] == 0.0).tolist(), 7 * [True] + 3 * [False])
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self.assertListEqual((scores[1] == 0.0).tolist(), 2 * [True] + 3 * [False] + 5 * [True])
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# check special cases
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length = 5
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logits = self._get_uniform_logits(batch_size=batch_size, length=length)
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scores = TopKProcess(logits, top_k=1, min_tokens_to_keep=3)
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# uniform dist is not changed
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self.assertListEqual((scores == 0.0).sum(axis=-1).tolist(), [0, 0])
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ramp_logits = paddle.arange(length).unsqueeze(0).tile((batch_size, 1))
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ramp_logits = ramp_logits.astype("float32")
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scores = TopKProcess(ramp_logits, top_k=1, min_tokens_to_keep=3)
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# min_tokens overwrites k: 3 tokens are kept => 2 tokens are nullified
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self.assertListEqual((scores == 0.0).sum(axis=-1).tolist(), [2, 2])
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def test_top_p_dist_warper(self):
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vocab_size = 10
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batch_size = 2
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# create distribution and take log (inverse to Softmax as taken in TopPProcess)
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# dist = paddle.log(paddle.to_tensor([[0.3, 0.1, 0.1, 0.5], [0.15, 0.3, 0.3, 0.25]]))
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dist = paddle.to_tensor([[0.3, 0.1, 0.1, 0.5], [0.15, 0.3, 0.3, 0.25]])
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# filtered_dist = paddle.exp(TopPProcess(dist, 0.80001, 1))
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filtered_dist = TopPProcess(dist, 0.79999, 1)
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EXPECTED_FILTERED_DIST = paddle.to_tensor([[0.3, 0.0, 0.0, 0.5], [0.0, 0.3, 0.3, 0.25]])
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self.assertTrue(paddle.allclose(filtered_dist, EXPECTED_FILTERED_DIST, atol=1e-3))
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# check edge cases with negative and extreme logits
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ramp_logits = paddle.arange(vocab_size).unsqueeze(0).tile((batch_size, 1)) - (vocab_size // 2)
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ramp_logits = ramp_logits.astype("float32")
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# make ramp_logits more extreme
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ramp_logits[1] = ramp_logits[1] * 10.0
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sft_ramp_logits = paddle.nn.functional.softmax(ramp_logits, axis=-1)
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# make sure at least 2 tokens are kept
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filtered_dist = TopPProcess(sft_ramp_logits, 0.9, min_tokens_to_keep=2)
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# first batch should keep three tokens, second batch would keep only 1, but due to `min_tokens_to_keep=2` keeps 2.
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self.assertListEqual((filtered_dist != 0.0).sum(axis=-1).tolist(), [3, 2])
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def test_no_repeat_ngram_dist_processor(self):
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vocab_size = 3
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batch_size = 2
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input_ids = paddle.to_tensor([[1, 1, 2, 1], [0, 1, 0, 1]])
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scores = self._get_uniform_logits(batch_size, vocab_size)
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no_repeat_proc_2_gram = NoRepeatNGramLogitsProcessor(2)
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no_repeat_proc_3_gram = NoRepeatNGramLogitsProcessor(3)
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filtered_scores_2_gram = no_repeat_proc_2_gram(input_ids, scores.clone())
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filtered_scores_3_gram = no_repeat_proc_3_gram(input_ids, scores.clone())
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# 2-gram would forbid 2nd and 3rd token (1,2) at 1st batch and 1st token (0) at 2nd batch
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self.assertListEqual(
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(filtered_scores_2_gram == paddle.finfo(scores.dtype).min).tolist(),
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[[False, True, True], [True, False, False]],
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)
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# 3-gram would forbid no token at 1st batch and 1st token (0) at 2nd batch
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self.assertListEqual(
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(filtered_scores_3_gram == paddle.finfo(scores.dtype).min).tolist(),
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[[False, False, False], [True, False, False]],
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)
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def test_processor_list(self):
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batch_size = 4
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sequence_length = 10
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vocab_size = 15
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eos_token_id = 0
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# dummy input_ids and scores
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input_ids = ids_tensor((batch_size, sequence_length), vocab_size)
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input_ids_comp = input_ids.clone()
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores_comp = scores.clone()
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# instantiate all dist processors
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min_dist_proc = MinLengthLogitsProcessor(min_length=10, eos_token_id=eos_token_id)
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temp_dist_warp = TemperatureLogitsWarper(temperature=0.5)
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rep_penalty_proc = RepetitionPenaltyLogitsProcessor(penalty=2.0)
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no_repeat_proc = NoRepeatNGramLogitsProcessor(2)
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# no processor list
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scores = min_dist_proc(input_ids, scores)
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scores = temp_dist_warp(input_ids, scores)
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scores = rep_penalty_proc(input_ids, scores)
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scores = no_repeat_proc(input_ids, scores)
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# with processor list
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processor = LogitsProcessorList(
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[
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min_dist_proc,
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temp_dist_warp,
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rep_penalty_proc,
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no_repeat_proc,
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]
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)
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scores_comp = processor(input_ids, scores_comp)
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# scores should be equal
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self.assertTrue(paddle.allclose(scores, scores_comp, atol=1e-3))
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# input_ids should never be changed
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self.assertListEqual(input_ids.tolist(), input_ids_comp.tolist())
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def test_hamming_diversity(self):
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vocab_size = 4
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num_beams = 2
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num_beam_groups = 2
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scores = self._get_uniform_logits(num_beams, vocab_size)
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# batch_idx = 0 -> index batch_idx * num_beam_groups -> idx = 0 * 2 = 0 -> penalises tokens 1
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# batch_idx = 1 -> index batch_idx * num_beam_groups -> idx = 1 * 2 = 2 -> penalises tokens 1
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current_tokens = paddle.to_tensor([0, 3, 1, 2])
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diversity_logits_processor = HammingDiversityLogitsProcessor(
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diversity_rate=1.0, num_beams=num_beams, num_beam_groups=num_beam_groups
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)
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processed_scores = diversity_logits_processor(None, scores, current_tokens, 1)
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self.assertTrue(
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paddle.allclose(processed_scores[0], paddle.to_tensor([-0.7500, 0.2500, 0.2500, 0.2500]), atol=1e-3)
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)
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self.assertTrue(
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paddle.allclose(processed_scores[1], paddle.to_tensor([0.2500, -0.7500, 0.2500, 0.2500]), atol=1e-3)
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)
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def test_forced_bos_token_logits_processor(self):
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vocab_size = 20
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batch_size = 4
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bos_token_id = 0
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logits_processor = ForcedBOSTokenLogitsProcessor(forced_bos_token_id=bos_token_id)
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# check that all scores are -inf except the bos_token_id score
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input_ids = ids_tensor((batch_size, 1), vocab_size=20)
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores = logits_processor(input_ids, scores)
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self.assertTrue((scores[:, bos_token_id + 1 :] == paddle.finfo(scores.dtype).min).all())
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self.assertListEqual(scores[:, bos_token_id].tolist(), 4 * [0]) # score for bos_token_id should be zero
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# check that bos_token_id is not forced if current length is greater than 1
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input_ids = ids_tensor((batch_size, 4), vocab_size=20)
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores = logits_processor(input_ids, scores)
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self.assertFalse((scores == paddle.finfo(scores.dtype).min).any())
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def test_forced_eos_token_logits_processor(self):
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vocab_size = 20
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batch_size = 4
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eos_token_id = 0
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max_length = 5
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logits_processor = ForcedEOSTokenLogitsProcessor(max_length=max_length, forced_eos_token_id=eos_token_id)
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# check that all scores are -inf except the eos_token_id when max_length-1 is reached
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input_ids = ids_tensor((batch_size, 4), vocab_size=20)
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores = logits_processor(input_ids, scores)
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self.assertTrue((scores[:, eos_token_id + 1 :] == paddle.finfo(scores.dtype).min).all())
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self.assertListEqual(scores[:, eos_token_id].tolist(), 4 * [0]) # score for eos_token_id should be zero
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# check that eos_token_id is not forced if max_length-1 is not reached
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input_ids = ids_tensor((batch_size, 3), vocab_size=20)
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scores = self._get_uniform_logits(batch_size, vocab_size)
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scores = logits_processor(input_ids, scores)
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self.assertFalse((scores == paddle.finfo(scores.dtype).min).any())
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def test_bias_dist_processor(self):
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vocab_size = 5
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batch_size = 2
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input_ids = paddle.to_tensor([[0, 1, 3, 1], [0, 1, 0, 1]])
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positive_bias = {(1,): 100.0, (4,): 100.0}
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negative_bias = {(1, 0): -100.0, (0, 1, 2): -100.0, (1, 3, 1, 3): -100.0}
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# biases the same termination twice, to ensure we can handle overlapping terminations (it won't have an effect
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# on the test cases, though)
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negative_bias.update({(1, 3, 1, 3, 1, 3): -100.0})
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sequence_bias = {**positive_bias, **negative_bias}
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# scores = 0 to facilitate checks
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scores = paddle.zeros((batch_size, vocab_size))
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bias_dist_proc = SequenceBiasLogitsProcessor(sequence_bias=sequence_bias)
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filtered_scores = bias_dist_proc(input_ids, scores.clone())
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# batch 1: positive bias: tokens (1, 4); negative bias: tokens (0, 3); neutral: tokens (2)
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# batch 2: positive bias: tokens (1, 4); negative bias: tokens (0, 2); neutral: tokens (3)
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self.assertListEqual(
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filtered_scores.tolist(), [[-100.0, 100.0, 0.0, -100.0, 100.0], [-100.0, 100.0, -100.0, 0.0, 100.0]]
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)
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def test_no_bad_words_dist_processor(self):
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vocab_size = 5
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batch_size = 2
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eos_token_id = 4
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input_ids = paddle.to_tensor([[0, 1, 3, 1], [0, 1, 0, 1]])
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bad_word_tokens = [[1], [4], [1, 0], [0, 1, 2], [1, 3, 1, 3]]
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scores = self._get_uniform_logits(batch_size, vocab_size)
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no_bad_words_dist_proc = NoBadWordsLogitsProcessor(bad_words_ids=bad_word_tokens, eos_token_id=eos_token_id)
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filtered_scores = no_bad_words_dist_proc(input_ids, scores.clone())
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# batch 1: 1st, 2nd, and 4th (0, 1, 3) token are forbidden
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# batch 2: 1st, 2nd, and 3rd (0, 1, 2) token are forbidden
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# Note that 5th element cannot be forbidden as it is EOS token
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self.assertListEqual(
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paddle.isinf(filtered_scores).tolist(),
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[[True, True, False, True, False], [True, True, True, False, False]],
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)
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# check edge case
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no_bad_words_dist_proc = NoBadWordsLogitsProcessor(bad_words_ids=[[4]], eos_token_id=eos_token_id)
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filtered_scores = no_bad_words_dist_proc(input_ids, scores.clone())
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self.assertTrue(paddle.allclose(scores, filtered_scores, atol=1e-3).numpy())
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def test_prefix_constrained_logits_processor(self):
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vocab_size = 5
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batch_size = 2
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input_ids = paddle.to_tensor([[0, 1, 3, 1], [0, 1, 0, 1]])
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scores = self._get_uniform_logits(batch_size, vocab_size)
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def prefix_allowed_tokens_fn(batch_id, inputs_ids):
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return [[0, 1], [2, 3]][batch_id]
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prefix_constrained_logits_proc = PrefixConstrainedLogitsProcessor(prefix_allowed_tokens_fn, 1)
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filtered_scores = prefix_constrained_logits_proc(input_ids, scores.clone())
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# batch 1: 1st, 2nd (0, 1) token are allowed
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# batch 2: 3rd, 4th (2, 3) token are allowed
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self.assertListEqual(
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(filtered_scores == paddle.finfo(filtered_scores.dtype).min).tolist(),
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[[False, False, True, True, True], [True, True, False, False, True]],
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)
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