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# 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 logging | |
import os | |
import numpy as np | |
from fairseq import utils | |
from fairseq.data import ( | |
ConcatSentencesDataset, | |
Dictionary, | |
IdDataset, | |
NestedDictionaryDataset, | |
NumelDataset, | |
NumSamplesDataset, | |
OffsetTokensDataset, | |
PrependTokenDataset, | |
RawLabelDataset, | |
RightPadDataset, | |
RollDataset, | |
SortDataset, | |
StripTokenDataset, | |
data_utils, | |
) | |
from fairseq.data.shorten_dataset import maybe_shorten_dataset | |
from fairseq.tasks import LegacyFairseqTask, register_task | |
logger = logging.getLogger(__name__) | |
class SentencePredictionTask(LegacyFairseqTask): | |
""" | |
Sentence (or sentence pair) prediction (classification or regression) task. | |
Args: | |
dictionary (Dictionary): the dictionary for the input of the task | |
""" | |
def add_args(parser): | |
"""Add task-specific arguments to the parser.""" | |
parser.add_argument("data", metavar="FILE", help="file prefix for data") | |
parser.add_argument( | |
"--num-classes", | |
type=int, | |
default=-1, | |
help="number of classes or regression targets", | |
) | |
parser.add_argument( | |
"--init-token", | |
type=int, | |
default=None, | |
help="add token at the beginning of each batch item", | |
) | |
parser.add_argument( | |
"--separator-token", | |
type=int, | |
default=None, | |
help="add separator token between inputs", | |
) | |
parser.add_argument("--regression-target", action="store_true", default=False) | |
parser.add_argument("--no-shuffle", action="store_true", default=False) | |
parser.add_argument( | |
"--shorten-method", | |
default="none", | |
choices=["none", "truncate", "random_crop"], | |
help="if not none, shorten sequences that exceed --tokens-per-sample", | |
) | |
parser.add_argument( | |
"--shorten-data-split-list", | |
default="", | |
help="comma-separated list of dataset splits to apply shortening to, " | |
'e.g., "train,valid" (default: all dataset splits)', | |
) | |
parser.add_argument( | |
"--add-prev-output-tokens", | |
action="store_true", | |
default=False, | |
help="add prev_output_tokens to sample, used for encoder-decoder arch", | |
) | |
def __init__(self, args, data_dictionary, label_dictionary): | |
super().__init__(args) | |
self.dictionary = data_dictionary | |
self._label_dictionary = label_dictionary | |
if not hasattr(args, "max_positions"): | |
self._max_positions = ( | |
args.max_source_positions, | |
args.max_target_positions, | |
) | |
else: | |
self._max_positions = args.max_positions | |
args.tokens_per_sample = self._max_positions | |
def load_dictionary(cls, args, filename, source=True): | |
"""Load the dictionary from the filename | |
Args: | |
filename (str): the filename | |
""" | |
dictionary = Dictionary.load(filename) | |
dictionary.add_symbol("<mask>") | |
return dictionary | |
def setup_task(cls, args, **kwargs): | |
assert args.num_classes > 0, "Must set --num-classes" | |
# load data dictionary | |
data_dict = cls.load_dictionary( | |
args, | |
os.path.join(args.data, "input0", "dict.txt"), | |
source=True, | |
) | |
logger.info("[input] dictionary: {} types".format(len(data_dict))) | |
# load label dictionary | |
if not args.regression_target: | |
label_dict = cls.load_dictionary( | |
args, | |
os.path.join(args.data, "label", "dict.txt"), | |
source=False, | |
) | |
logger.info("[label] dictionary: {} types".format(len(label_dict))) | |
else: | |
label_dict = data_dict | |
return cls(args, data_dict, label_dict) | |
def load_dataset(self, split, combine=False, **kwargs): | |
"""Load a given dataset split (e.g., train, valid, test).""" | |
def get_path(key, split): | |
return os.path.join(self.args.data, key, split) | |
def make_dataset(key, dictionary): | |
split_path = get_path(key, split) | |
dataset = data_utils.load_indexed_dataset( | |
split_path, | |
dictionary, | |
self.args.dataset_impl, | |
combine=combine, | |
) | |
return dataset | |
input0 = make_dataset("input0", self.source_dictionary) | |
assert input0 is not None, "could not find dataset: {}".format( | |
get_path("input0", split) | |
) | |
input1 = make_dataset("input1", self.source_dictionary) | |
if self.args.init_token is not None: | |
input0 = PrependTokenDataset(input0, self.args.init_token) | |
if input1 is None: | |
src_tokens = input0 | |
else: | |
if self.args.separator_token is not None: | |
input1 = PrependTokenDataset(input1, self.args.separator_token) | |
src_tokens = ConcatSentencesDataset(input0, input1) | |
with data_utils.numpy_seed(self.args.seed): | |
shuffle = np.random.permutation(len(src_tokens)) | |
src_tokens = maybe_shorten_dataset( | |
src_tokens, | |
split, | |
self.args.shorten_data_split_list, | |
self.args.shorten_method, | |
self.max_positions(), | |
self.args.seed, | |
) | |
dataset = { | |
"id": IdDataset(), | |
"net_input": { | |
"src_tokens": RightPadDataset( | |
src_tokens, | |
pad_idx=self.source_dictionary.pad(), | |
), | |
"src_lengths": NumelDataset(src_tokens, reduce=False), | |
}, | |
"nsentences": NumSamplesDataset(), | |
"ntokens": NumelDataset(src_tokens, reduce=True), | |
} | |
if self.args.add_prev_output_tokens: | |
prev_tokens_dataset = RightPadDataset( | |
RollDataset(src_tokens, 1), | |
pad_idx=self.dictionary.pad(), | |
) | |
dataset["net_input"].update( | |
prev_output_tokens=prev_tokens_dataset, | |
) | |
if not self.args.regression_target: | |
label_dataset = make_dataset("label", self.label_dictionary) | |
if label_dataset is not None: | |
dataset.update( | |
target=OffsetTokensDataset( | |
StripTokenDataset( | |
label_dataset, | |
id_to_strip=self.label_dictionary.eos(), | |
), | |
offset=-self.label_dictionary.nspecial, | |
) | |
) | |
else: | |
label_path = "{0}.label".format(get_path("label", split)) | |
if os.path.exists(label_path): | |
def parse_regression_target(i, line): | |
values = line.split() | |
assert ( | |
len(values) == self.args.num_classes | |
), f'expected num_classes={self.args.num_classes} regression target values on line {i}, found: "{line}"' | |
return [float(x) for x in values] | |
with open(label_path) as h: | |
dataset.update( | |
target=RawLabelDataset( | |
[ | |
parse_regression_target(i, line.strip()) | |
for i, line in enumerate(h.readlines()) | |
] | |
) | |
) | |
nested_dataset = NestedDictionaryDataset( | |
dataset, | |
sizes=[src_tokens.sizes], | |
) | |
if self.args.no_shuffle: | |
dataset = nested_dataset | |
else: | |
dataset = SortDataset( | |
nested_dataset, | |
# shuffle | |
sort_order=[shuffle], | |
) | |
logger.info("Loaded {0} with #samples: {1}".format(split, len(dataset))) | |
self.datasets[split] = dataset | |
return self.datasets[split] | |
def build_model(self, args): | |
from fairseq import models | |
model = models.build_model(args, self) | |
model.register_classification_head( | |
getattr(args, "classification_head_name", "sentence_classification_head"), | |
num_classes=self.args.num_classes, | |
) | |
return model | |
def max_positions(self): | |
return self._max_positions | |
def source_dictionary(self): | |
return self.dictionary | |
def target_dictionary(self): | |
return self.dictionary | |
def label_dictionary(self): | |
return self._label_dictionary | |