chore: import upstream snapshot with attribution
This commit is contained in:
@@ -0,0 +1 @@
|
||||
from .translation_lev_modified import *
|
||||
@@ -0,0 +1,289 @@
|
||||
# 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.
|
||||
|
||||
from dataclasses import dataclass, field
|
||||
from math import log
|
||||
import torch
|
||||
from fairseq import utils
|
||||
from fairseq.data import LanguagePairDataset
|
||||
from fairseq.dataclass import ChoiceEnum
|
||||
from fairseq.tasks import register_task
|
||||
from fairseq.tasks.translation import TranslationConfig, TranslationTask, load_langpair_dataset
|
||||
from fairseq.utils import new_arange
|
||||
import logging
|
||||
from omegaconf import II
|
||||
import numpy as np
|
||||
|
||||
NOISE_CHOICES = ChoiceEnum(["random_delete", "random_mask", "no_noise", "full_mask", "block_mask"])
|
||||
|
||||
|
||||
@dataclass
|
||||
class TranslationLevenshteinConfig(TranslationConfig):
|
||||
noise: NOISE_CHOICES = field(
|
||||
default="random_delete",
|
||||
metadata={
|
||||
"help": "type of noise"
|
||||
},
|
||||
)
|
||||
start_p: float = field(
|
||||
default=0.5, metadata={"help": "minus prob"}
|
||||
)
|
||||
minus_p: float = field(
|
||||
default=0.2, metadata={"help": "minus prob"}
|
||||
)
|
||||
total_up: int = field(
|
||||
default=300000, metadata={"help": "total updates"}
|
||||
)
|
||||
block_size: int = field(
|
||||
default=5, metadata={"help": "block size"}
|
||||
)
|
||||
|
||||
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
|
||||
@register_task("translation_lev_modified", dataclass=TranslationLevenshteinConfig)
|
||||
class TranslationLevenshteinModifiedTask(TranslationTask):
|
||||
"""
|
||||
Translation (Sequence Generation) task for Levenshtein Transformer
|
||||
See `"Levenshtein Transformer" <https://arxiv.org/abs/1905.11006>`_.
|
||||
"""
|
||||
|
||||
cfg: TranslationLevenshteinConfig
|
||||
|
||||
def load_dataset(self, split, epoch=1, combine=False, **kwargs):
|
||||
"""Load a given dataset split.
|
||||
|
||||
Args:
|
||||
split (str): name of the split (e.g., train, valid, test)
|
||||
"""
|
||||
paths = utils.split_paths(self.cfg.data)
|
||||
assert len(paths) > 0
|
||||
data_path = paths[(epoch - 1) % len(paths)]
|
||||
|
||||
# infer langcode
|
||||
src, tgt = self.cfg.source_lang, self.cfg.target_lang
|
||||
|
||||
self.datasets[split] = load_langpair_dataset(
|
||||
data_path,
|
||||
split,
|
||||
src,
|
||||
self.src_dict,
|
||||
tgt,
|
||||
self.tgt_dict,
|
||||
combine=combine,
|
||||
dataset_impl=self.cfg.dataset_impl,
|
||||
upsample_primary=self.cfg.upsample_primary,
|
||||
left_pad_source=self.cfg.left_pad_source,
|
||||
left_pad_target=self.cfg.left_pad_target,
|
||||
max_source_positions=self.cfg.max_source_positions,
|
||||
max_target_positions=self.cfg.max_target_positions,
|
||||
truncate_source=self.cfg.truncate_source,
|
||||
)
|
||||
|
||||
def inject_noise(self, target_tokens):
|
||||
def _random_delete(target_tokens):
|
||||
pad = self.tgt_dict.pad()
|
||||
bos = self.tgt_dict.bos()
|
||||
eos = self.tgt_dict.eos()
|
||||
|
||||
max_len = target_tokens.size(1)
|
||||
target_mask = target_tokens.eq(pad)
|
||||
target_score = target_tokens.clone().float().uniform_()
|
||||
target_score.masked_fill_(
|
||||
target_tokens.eq(bos) | target_tokens.eq(eos), 0.0
|
||||
)
|
||||
target_score.masked_fill_(target_mask, 1)
|
||||
target_score, target_rank = target_score.sort(1)
|
||||
target_length = target_mask.size(1) - target_mask.float().sum(
|
||||
1, keepdim=True
|
||||
)
|
||||
|
||||
# do not delete <bos> and <eos> (we assign 0 score for them)
|
||||
target_cutoff = (
|
||||
2
|
||||
+ (
|
||||
(target_length - 2)
|
||||
* target_score.new_zeros(target_score.size(0), 1).uniform_()
|
||||
).long()
|
||||
)
|
||||
target_cutoff = target_score.sort(1)[1] >= target_cutoff
|
||||
|
||||
prev_target_tokens = (
|
||||
target_tokens.gather(1, target_rank)
|
||||
.masked_fill_(target_cutoff, pad)
|
||||
.gather(1, target_rank.masked_fill_(target_cutoff, max_len).sort(1)[1])
|
||||
)
|
||||
prev_target_tokens = prev_target_tokens[
|
||||
:, : prev_target_tokens.ne(pad).sum(1).max()
|
||||
]
|
||||
|
||||
return prev_target_tokens
|
||||
|
||||
def _random_mask(target_tokens):
|
||||
pad = self.tgt_dict.pad()
|
||||
bos = self.tgt_dict.bos()
|
||||
eos = self.tgt_dict.eos()
|
||||
unk = self.tgt_dict.unk()
|
||||
|
||||
target_masks = (
|
||||
target_tokens.ne(pad) & target_tokens.ne(bos) & target_tokens.ne(eos)
|
||||
)
|
||||
target_score = target_tokens.clone().float().uniform_()
|
||||
target_score.masked_fill_(~target_masks, 2.0)
|
||||
target_length = target_masks.sum(1).float()
|
||||
target_length = target_length * target_length.clone().uniform_()
|
||||
target_length = target_length + 1 # make sure to mask at least one token.
|
||||
|
||||
_, target_rank = target_score.sort(1)
|
||||
target_cutoff = new_arange(target_rank) < target_length[:, None].long()
|
||||
prev_target_tokens = target_tokens.masked_fill(
|
||||
target_cutoff.scatter(1, target_rank, target_cutoff), unk
|
||||
)
|
||||
return prev_target_tokens
|
||||
|
||||
def _full_mask(target_tokens):
|
||||
pad = self.tgt_dict.pad()
|
||||
bos = self.tgt_dict.bos()
|
||||
eos = self.tgt_dict.eos()
|
||||
unk = self.tgt_dict.unk()
|
||||
|
||||
target_mask = (
|
||||
target_tokens.eq(bos) | target_tokens.eq(eos) | target_tokens.eq(pad)
|
||||
)
|
||||
return target_tokens.masked_fill(~target_mask, unk)
|
||||
|
||||
def _block_mask(target_tokens):
|
||||
block_size = self.cfg.block_size
|
||||
pad = self.tgt_dict.pad()
|
||||
unk = self.tgt_dict.unk()
|
||||
target_masks = target_tokens.ne(pad)
|
||||
target_length = target_masks.sum(1).float()
|
||||
cutoff_length = target_length * target_length.clone().uniform_()
|
||||
cutoff_length = cutoff_length.int() + 1 # make sure to mask at least one token.
|
||||
prev_target_tokens = torch.ones((target_tokens.size(0),
|
||||
target_tokens.size(1) + block_size)).to(target_tokens)
|
||||
padded_target_tokens = torch.ones((target_tokens.size(0),
|
||||
target_tokens.size(1) + block_size)).to(target_tokens)
|
||||
for i in range(target_tokens.size(0)):
|
||||
remain_length = target_length[i].int() - cutoff_length[i]
|
||||
prev_target_tokens[i][:remain_length] = target_tokens[i][:remain_length]
|
||||
prev_target_tokens[i][remain_length:block_size + remain_length] = unk
|
||||
padded_target_tokens[i][:target_tokens.size(1)] = target_tokens[i]
|
||||
prev_target_tokens = prev_target_tokens[
|
||||
:, : prev_target_tokens.ne(pad).sum(1).max()
|
||||
]
|
||||
padded_target_tokens = padded_target_tokens[
|
||||
:, : prev_target_tokens.ne(pad).sum(1).max()
|
||||
]
|
||||
return prev_target_tokens, padded_target_tokens
|
||||
|
||||
if self.cfg.noise == "random_delete":
|
||||
return _random_delete(target_tokens)
|
||||
elif self.cfg.noise == "random_mask":
|
||||
return _random_mask(target_tokens)
|
||||
elif self.cfg.noise == "block_mask":
|
||||
return _block_mask(target_tokens)
|
||||
elif self.cfg.noise == "full_mask":
|
||||
return _full_mask(target_tokens)
|
||||
elif self.cfg.noise == "no_noise":
|
||||
return target_tokens
|
||||
else:
|
||||
raise NotImplementedError
|
||||
|
||||
def build_generator(self, models, args, **unused):
|
||||
# add models input to match the API for SequenceGenerator
|
||||
from fairseq.iterative_refinement_generator import IterativeRefinementGenerator
|
||||
|
||||
return IterativeRefinementGenerator(
|
||||
self.target_dictionary,
|
||||
eos_penalty=getattr(args, "iter_decode_eos_penalty", 0.0),
|
||||
max_iter=getattr(args, "iter_decode_max_iter", 10),
|
||||
beam_size=getattr(args, "iter_decode_with_beam", 1),
|
||||
reranking=getattr(args, "iter_decode_with_external_reranker", False),
|
||||
decoding_format=getattr(args, "decoding_format", None),
|
||||
adaptive=not getattr(args, "iter_decode_force_max_iter", False),
|
||||
retain_history=getattr(args, "retain_iter_history", False),
|
||||
)
|
||||
|
||||
def build_dataset_for_inference(self, src_tokens, src_lengths, constraints=None):
|
||||
if constraints is not None:
|
||||
# Though see Susanto et al. (ACL 2020): https://www.aclweb.org/anthology/2020.acl-main.325/
|
||||
raise NotImplementedError(
|
||||
"Constrained decoding with the translation_lev task is not supported"
|
||||
)
|
||||
|
||||
return LanguagePairDataset(
|
||||
src_tokens, src_lengths, self.source_dictionary, append_bos=False
|
||||
)
|
||||
|
||||
def train_step(
|
||||
self, sample, model, criterion, optimizer, update_num, ignore_grad=False
|
||||
):
|
||||
model.train()
|
||||
train_ratio = max(0, min(1, update_num / self.cfg.total_up))
|
||||
sample["glat"] = {"context_p": self.cfg.start_p - self.cfg.minus_p * train_ratio}
|
||||
sample["prev_target"], sample["target"] = self.inject_noise(sample["target"])
|
||||
with torch.autograd.profiler.record_function("forward"):
|
||||
loss, sample_size, logging_output = criterion(model, sample)
|
||||
if ignore_grad:
|
||||
loss *= 0
|
||||
with torch.autograd.profiler.record_function("backward"):
|
||||
optimizer.backward(loss)
|
||||
return loss, sample_size, logging_output
|
||||
|
||||
def valid_step(self, sample, model, criterion):
|
||||
model.eval()
|
||||
with torch.no_grad():
|
||||
sample["prev_target"], sample["target"] = self.inject_noise(sample["target"])
|
||||
loss, sample_size, logging_output = criterion(model, sample)
|
||||
EVAL_BLEU_ORDER = 4
|
||||
if self.cfg.eval_bleu:
|
||||
bleu = self._inference_with_bleu(self.sequence_generator, sample, model)
|
||||
logging_output["_bleu_sys_len"] = bleu.sys_len
|
||||
logging_output["_bleu_ref_len"] = bleu.ref_len
|
||||
# we split counts into separate entries so that they can be
|
||||
# summed efficiently across workers using fast-stat-sync
|
||||
assert len(bleu.counts) == EVAL_BLEU_ORDER
|
||||
for i in range(EVAL_BLEU_ORDER):
|
||||
logging_output["_bleu_counts_" + str(i)] = bleu.counts[i]
|
||||
logging_output["_bleu_totals_" + str(i)] = bleu.totals[i]
|
||||
return loss, sample_size, logging_output
|
||||
|
||||
def _inference_with_bleu(self, generator, sample, model):
|
||||
import sacrebleu
|
||||
|
||||
def decode(toks, escape_unk=False):
|
||||
s = self.tgt_dict.string(
|
||||
toks.int().cpu(),
|
||||
self.cfg.eval_bleu_remove_bpe,
|
||||
# The default unknown string in fairseq is `<unk>`, but
|
||||
# this is tokenized by sacrebleu as `< unk >`, inflating
|
||||
# BLEU scores. Instead, we use a somewhat more verbose
|
||||
# alternative that is unlikely to appear in the real
|
||||
# reference, but doesn't get split into multiple tokens.
|
||||
unk_string=("UNKNOWNTOKENINREF" if escape_unk else "UNKNOWNTOKENINHYP"),
|
||||
)
|
||||
if self.tokenizer:
|
||||
s = self.tokenizer.decode(s)
|
||||
return s
|
||||
|
||||
gen_out = self.inference_step(generator, [model], sample, prefix_tokens=None)
|
||||
hyps, refs = [], []
|
||||
for i in range(len(gen_out)):
|
||||
hyps.append(decode(gen_out[i][0]["tokens"]))
|
||||
refs.append(
|
||||
decode(
|
||||
utils.strip_pad(sample["target"][i], self.tgt_dict.pad()),
|
||||
escape_unk=True, # don't count <unk> as matches to the hypo
|
||||
)
|
||||
)
|
||||
if self.cfg.eval_bleu_print_samples:
|
||||
logger.info("example hypothesis: " + hyps[0])
|
||||
logger.info("example reference: " + refs[0])
|
||||
if self.cfg.eval_tokenized_bleu:
|
||||
return sacrebleu.corpus_bleu(hyps, [refs], tokenize="none")
|
||||
else:
|
||||
return sacrebleu.corpus_bleu(hyps, [refs])
|
||||
Reference in New Issue
Block a user