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2026-07-13 13:24:13 +08:00

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Python

# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
import json
import os
import tempfile
import numpy as np
import torch
import torch.nn.functional as F
from fairseq import utils
from fairseq.data import (
data_utils,
Dictionary,
encoders,
IdDataset,
ListDataset,
NestedDictionaryDataset,
NumSamplesDataset,
NumelDataset,
PadDataset,
SortDataset,
)
from fairseq.tasks import FairseqTask, register_task
from . import wsc_utils
@register_task('wsc')
class WSCTask(FairseqTask):
"""Task to finetune RoBERTa for Winograd Schemas."""
@staticmethod
def add_args(parser):
"""Add task-specific arguments to the parser."""
parser.add_argument('data', metavar='DIR',
help='path to data directory; we load <split>.jsonl')
parser.add_argument('--init-token', type=int, default=None,
help='add token at the beginning of each batch item')
def __init__(self, args, vocab):
super().__init__(args)
self.vocab = vocab
self.mask = vocab.add_symbol('<mask>')
self.bpe = encoders.build_bpe(args)
self.tokenizer = encoders.build_tokenizer(args)
# hack to handle GPT-2 BPE, which includes leading spaces
if args.bpe == 'gpt2':
self.leading_space = True
self.trailing_space = False
else:
self.leading_space = False
self.trailing_space = True
@classmethod
def load_dictionary(cls, filename):
"""Load the dictionary from the filename
Args:
filename (str): the filename
"""
dictionary = Dictionary.load(filename)
dictionary.add_symbol('<mask>')
return dictionary
@classmethod
def setup_task(cls, args, **kwargs):
assert args.criterion == 'wsc', 'Must set --criterion=wsc'
# load data and label dictionaries
vocab = cls.load_dictionary(os.path.join(args.data, 'dict.txt'))
print('| dictionary: {} types'.format(len(vocab)))
return cls(args, vocab)
def binarize(self, s: str, append_eos: bool = False):
if self.tokenizer is not None:
s = self.tokenizer.encode(s)
if self.bpe is not None:
s = self.bpe.encode(s)
tokens = self.vocab.encode_line(
s, append_eos=append_eos, add_if_not_exist=False,
).long()
if self.args.init_token is not None:
tokens = torch.cat([tokens.new([self.args.init_token]), tokens])
return tokens
def binarize_with_mask(self, txt, prefix, suffix, leading_space, trailing_space):
toks = self.binarize(
prefix + leading_space + txt + trailing_space + suffix,
append_eos=True,
)
mask = torch.zeros_like(toks, dtype=torch.uint8)
mask_start = len(self.binarize(prefix))
mask_size = len(self.binarize(leading_space + txt))
mask[mask_start:mask_start + mask_size] = 1
return toks, mask
def load_dataset(self, split, epoch=0, combine=False, data_path=None, return_only=False, **kwargs):
"""Load a given dataset split.
Args:
split (str): name of the split (e.g., train, valid, test)
"""
if data_path is None:
data_path = os.path.join(self.args.data, split + '.jsonl')
if not os.path.exists(data_path):
raise FileNotFoundError('Cannot find data: {}'.format(data_path))
query_tokens = []
query_masks = []
query_lengths = []
candidate_tokens = []
candidate_masks = []
candidate_lengths = []
labels = []
for sentence, pronoun_span, query, label in wsc_utils.jsonl_iterator(data_path):
prefix = sentence[:pronoun_span.start].text
suffix = sentence[pronoun_span.end:].text_with_ws
# spaCy spans include trailing spaces, but we need to know about
# leading spaces for the GPT-2 BPE
leading_space = ' ' if sentence[:pronoun_span.start].text_with_ws.endswith(' ') else ''
trailing_space = ' ' if pronoun_span.text_with_ws.endswith(' ') else ''
# get noun phrases, excluding pronouns and anything overlapping with the query
cand_spans = wsc_utils.filter_noun_chunks(
wsc_utils.extended_noun_chunks(sentence),
exclude_pronouns=True,
exclude_query=query,
exact_match=False,
)
if query is not None:
query_toks, query_mask = self.binarize_with_mask(
query, prefix, suffix, leading_space, trailing_space
)
query_len = len(query_toks)
else:
query_toks, query_mask, query_len = None, None, 0
query_tokens.append(query_toks)
query_masks.append(query_mask)
query_lengths.append(query_len)
cand_toks, cand_masks = [], []
for cand_span in cand_spans:
toks, mask = self.binarize_with_mask(
cand_span.text, prefix, suffix, leading_space, trailing_space,
)
cand_toks.append(toks)
cand_masks.append(mask)
# collate candidates
cand_toks = data_utils.collate_tokens(cand_toks, pad_idx=self.vocab.pad())
cand_masks = data_utils.collate_tokens(cand_masks, pad_idx=0)
assert cand_toks.size() == cand_masks.size()
candidate_tokens.append(cand_toks)
candidate_masks.append(cand_masks)
candidate_lengths.append(cand_toks.size(1))
labels.append(label)
query_lengths = np.array(query_lengths)
query_tokens = ListDataset(query_tokens, query_lengths)
query_masks = ListDataset(query_masks, query_lengths)
candidate_lengths = np.array(candidate_lengths)
candidate_tokens = ListDataset(candidate_tokens, candidate_lengths)
candidate_masks = ListDataset(candidate_masks, candidate_lengths)
labels = ListDataset(labels, [1]*len(labels))
dataset = {
'id': IdDataset(),
'query_tokens': query_tokens,
'query_masks': query_masks,
'candidate_tokens': candidate_tokens,
'candidate_masks': candidate_masks,
'labels': labels,
'nsentences': NumSamplesDataset(),
'ntokens': NumelDataset(query_tokens, reduce=True),
}
nested_dataset = NestedDictionaryDataset(
dataset,
sizes=[query_lengths],
)
with data_utils.numpy_seed(self.args.seed):
shuffle = np.random.permutation(len(query_tokens))
dataset = SortDataset(
nested_dataset,
# shuffle
sort_order=[shuffle],
)
if return_only:
return dataset
self.datasets[split] = dataset
return self.datasets[split]
def build_dataset_for_inference(self, sample_json):
with tempfile.NamedTemporaryFile(buffering=0) as h:
h.write((json.dumps(sample_json) + '\n').encode('utf-8'))
dataset = self.load_dataset(
'disambiguate_pronoun',
data_path=h.name,
return_only=True,
)
return dataset
def disambiguate_pronoun(self, model, sentence, use_cuda=False):
sample_json = wsc_utils.convert_sentence_to_json(sentence)
dataset = self.build_dataset_for_inference(sample_json)
sample = dataset.collater([dataset[0]])
if use_cuda:
sample = utils.move_to_cuda(sample)
def get_masked_input(tokens, mask):
masked_tokens = tokens.clone()
masked_tokens[mask.bool()] = self.mask
return masked_tokens
def get_lprobs(tokens, mask):
logits, _ = model(src_tokens=get_masked_input(tokens, mask))
lprobs = F.log_softmax(logits, dim=-1, dtype=torch.float)
scores = lprobs.gather(2, tokens.unsqueeze(-1)).squeeze(-1)
mask = mask.type_as(scores)
scores = (scores * mask).sum(dim=-1) / mask.sum(dim=-1)
return scores
cand_lprobs = get_lprobs(
sample['candidate_tokens'][0],
sample['candidate_masks'][0],
)
if sample['query_tokens'][0] is not None:
query_lprobs = get_lprobs(
sample['query_tokens'][0].unsqueeze(0),
sample['query_masks'][0].unsqueeze(0),
)
return (query_lprobs >= cand_lprobs).all().item() == 1
else:
best_idx = cand_lprobs.argmax().item()
full_cand = sample['candidate_tokens'][0][best_idx]
mask = sample['candidate_masks'][0][best_idx]
toks = full_cand[mask.bool()]
return self.bpe.decode(self.source_dictionary.string(toks)).strip()
@property
def source_dictionary(self):
return self.vocab
@property
def target_dictionary(self):
return self.vocab
@register_task('winogrande')
class WinograndeTask(WSCTask):
"""
Task for WinoGrande dataset. Efficient implementation for Winograd schema
tasks with exactly two candidates, one of which is correct.
"""
@classmethod
def setup_task(cls, args, **kwargs):
assert args.criterion == 'winogrande', 'Must set --criterion=winogrande'
# load data and label dictionaries
vocab = cls.load_dictionary(os.path.join(args.data, 'dict.txt'))
print('| dictionary: {} types'.format(len(vocab)))
return cls(args, vocab)
def load_dataset(self, split, epoch=0, combine=False, data_path=None, return_only=False, **kwargs):
"""Load a given dataset split.
Args:
split (str): name of the split (e.g., train, valid, test)
"""
if data_path is None:
data_path = os.path.join(self.args.data, split + '.jsonl')
if not os.path.exists(data_path):
raise FileNotFoundError('Cannot find data: {}'.format(data_path))
query_tokens = []
query_masks = []
query_lengths = []
candidate_tokens = []
candidate_masks = []
candidate_lengths = []
itr = wsc_utils.winogrande_jsonl_iterator(data_path, eval=(split == 'test'))
for sample in itr:
sentence, pronoun_span, query, cand_text = sample
prefix = sentence[:pronoun_span[0]].rstrip()
suffix = sentence[pronoun_span[1]:]
leading_space = ' ' if sentence[:pronoun_span[0]].endswith(' ') else ''
trailing_space = ''
if query is not None:
query_toks, query_mask = self.binarize_with_mask(
query, prefix, suffix, leading_space, trailing_space,
)
query_len = len(query_toks)
else:
query_toks, query_mask, query_len = None, None, 0
query_tokens.append(query_toks)
query_masks.append(query_mask)
query_lengths.append(query_len)
cand_toks, cand_mask = self.binarize_with_mask(
cand_text, prefix, suffix, leading_space, trailing_space,
)
candidate_tokens.append(cand_toks)
candidate_masks.append(cand_mask)
candidate_lengths.append(cand_toks.size(0))
query_lengths = np.array(query_lengths)
def get_pad_dataset_fn(tokens, length, pad_idx):
return PadDataset(
ListDataset(tokens, length),
pad_idx=pad_idx,
left_pad=False,
)
query_tokens = get_pad_dataset_fn(query_tokens, query_lengths, self.vocab.pad())
query_masks = get_pad_dataset_fn(query_masks, query_lengths, 0)
candidate_lengths = np.array(candidate_lengths)
candidate_tokens = get_pad_dataset_fn(candidate_tokens, candidate_lengths, self.vocab.pad())
candidate_masks = get_pad_dataset_fn(candidate_masks, candidate_lengths, 0)
dataset = {
'id': IdDataset(),
'query_tokens': query_tokens,
'query_masks': query_masks,
'candidate_tokens': candidate_tokens,
'candidate_masks': candidate_masks,
'nsentences': NumSamplesDataset(),
'ntokens': NumelDataset(query_tokens, reduce=True),
}
nested_dataset = NestedDictionaryDataset(
dataset,
sizes=[query_lengths],
)
with data_utils.numpy_seed(self.args.seed):
shuffle = np.random.permutation(len(query_tokens))
dataset = SortDataset(
nested_dataset,
# shuffle
sort_order=[shuffle],
)
if return_only:
return dataset
self.datasets[split] = dataset
return self.datasets[split]