# 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.
try:
from collections.abc import Iterable
except ImportError:
from collections import Iterable
import contextlib
import itertools
import logging
import re
import warnings
from typing import Optional, Tuple
import numpy as np
import torch
from fairseq.file_io import PathManager
from fairseq import utils
import os
logger = logging.getLogger(__name__)
def infer_language_pair(path):
"""Infer language pair from filename: <split>.<lang1>-<lang2>.(...).idx"""
src, dst = None, None
for filename in PathManager.ls(path):
parts = filename.split(".")
if len(parts) >= 3 and len(parts[1].split("-")) == 2:
return parts[1].split("-")
return src, dst
def collate_tokens(
values,
pad_idx,
eos_idx=None,
left_pad=False,
move_eos_to_beginning=False,
pad_to_length=None,
pad_to_multiple=1,
pad_to_bsz=None,
):
"""Convert a list of 1d tensors into a padded 2d tensor."""
size = max(v.size(0) for v in values)
size = size if pad_to_length is None else max(size, pad_to_length)
if pad_to_multiple != 1 and size % pad_to_multiple != 0:
size = int(((size - 0.1) // pad_to_multiple + 1) * pad_to_multiple)
def copy_tensor(src, dst):
assert dst.numel() == src.numel()
if move_eos_to_beginning:
if eos_idx is None:
# if no eos_idx is specified, then use the last token in src
dst[0] = src[-1]
else:
dst[0] = eos_idx
dst[1:] = src[:-1]
else:
dst.copy_(src)
if values[0].dim() == 1:
res = values[0].new(len(values), size).fill_(pad_idx)
elif values[0].dim() == 2:
assert move_eos_to_beginning is False
res = values[0].new(len(values), size, values[0].size(1)).fill_(pad_idx)
else:
raise NotImplementedError
for i, v in enumerate(values):
copy_tensor(v, res[i][size - len(v) :] if left_pad else res[i][: len(v)])
return res
def load_indexed_dataset(
path, dictionary=None, dataset_impl=None, combine=False, default="cached"
):
"""A helper function for loading indexed datasets.
Args:
path (str): path to indexed dataset (e.g., 'data-bin/train')
dictionary (~fairseq.data.Dictionary): data dictionary
dataset_impl (str, optional): which dataset implementation to use. If
not provided, it will be inferred automatically. For legacy indexed
data we use the 'cached' implementation by default.
combine (bool, optional): automatically load and combine multiple
datasets. For example, if *path* is 'data-bin/train', then we will
combine 'data-bin/train', 'data-bin/train1', ... and return a
single ConcatDataset instance.
"""
import fairseq.data.indexed_dataset as indexed_dataset
from fairseq.data.concat_dataset import ConcatDataset
datasets = []
for k in itertools.count():
path_k = path + (str(k) if k > 0 else "")
try:
path_k = indexed_dataset.get_indexed_dataset_to_local(path_k)
except Exception as e:
if "StorageException: [404] Path not found" in str(e):
logger.warning(f"path_k: {e} not found")
else:
raise e
dataset_impl_k = dataset_impl
if dataset_impl_k is None:
dataset_impl_k = indexed_dataset.infer_dataset_impl(path_k)
dataset = indexed_dataset.make_dataset(
path_k,
impl=dataset_impl_k or default,
fix_lua_indexing=True,
dictionary=dictionary,
)
if dataset is None:
break
logger.info("loaded {:,} examples from: {}".format(len(dataset), path_k))
datasets.append(dataset)
if not combine:
break
if len(datasets) == 0:
return None
elif len(datasets) == 1:
return datasets[0]
else:
return ConcatDataset(datasets)
@contextlib.contextmanager
def numpy_seed(seed, *addl_seeds):
"""Context manager which seeds the NumPy PRNG with the specified seed and
restores the state afterward"""
if seed is None:
yield
return
if len(addl_seeds) > 0:
seed = int(hash((seed, *addl_seeds)) % 1e6)
state = np.random.get_state()
np.random.seed(seed)
try:
yield
finally:
np.random.set_state(state)
def collect_filtered(function, iterable, filtered):
"""
Similar to :func:`filter` but collects filtered elements in ``filtered``.
Args:
function (callable): function that returns ``False`` for elements that
should be filtered
iterable (iterable): iterable to filter
filtered (list): list to store filtered elements
"""
for el in iterable:
if function(el):
yield el
else:
filtered.append(el)
def _filter_by_size_dynamic(indices, size_fn, max_positions, raise_exception=False):
def compare_leq(a, b):
return a <= b if not isinstance(a, tuple) else max(a) <= b
def check_size(idx):
if isinstance(max_positions, float) or isinstance(max_positions, int):
return size_fn(idx) <= max_positions
elif isinstance(max_positions, dict):
idx_size = size_fn(idx)
assert isinstance(idx_size, dict)
intersect_keys = set(max_positions.keys()) & set(idx_size.keys())
return all(
all(
a is None or b is None or a <= b
for a, b in zip(idx_size[key], max_positions[key])
)
for key in intersect_keys
)
else:
# For MultiCorpusSampledDataset, will generalize it later
if not isinstance(size_fn(idx), Iterable):
return all(size_fn(idx) <= b for b in max_positions)
return all(
a is None or b is None or a <= b
for a, b in zip(size_fn(idx), max_positions)
)
ignored = []
itr = collect_filtered(check_size, indices, ignored)
indices = np.fromiter(itr, dtype=np.int64, count=-1)
return indices, ignored
def filter_by_size(indices, dataset, max_positions, raise_exception=False):
"""
[deprecated] Filter indices based on their size.
Use `FairseqDataset::filter_indices_by_size` instead.
Args:
indices (List[int]): ordered list of dataset indices
dataset (FairseqDataset): fairseq dataset instance
max_positions (tuple): filter elements larger than this size.
Comparisons are done component-wise.
raise_exception (bool, optional): if ``True``, raise an exception if
any elements are filtered (default: False).
"""
warnings.warn(
"data_utils.filter_by_size is deprecated. "
"Use `FairseqDataset::filter_indices_by_size` instead.",
stacklevel=2,
)
if isinstance(max_positions, float) or isinstance(max_positions, int):
if hasattr(dataset, "sizes") and isinstance(dataset.sizes, np.ndarray):
ignored = indices[dataset.sizes[indices] > max_positions].tolist()
indices = indices[dataset.sizes[indices] <= max_positions]
elif (
hasattr(dataset, "sizes")
and isinstance(dataset.sizes, list)
and len(dataset.sizes) == 1
):
ignored = indices[dataset.sizes[0][indices] > max_positions].tolist()
indices = indices[dataset.sizes[0][indices] <= max_positions]
else:
indices, ignored = _filter_by_size_dynamic(
indices, dataset.size, max_positions
)
else:
indices, ignored = _filter_by_size_dynamic(indices, dataset.size, max_positions)
if len(ignored) > 0 and raise_exception:
raise Exception(
(
"Size of sample #{} is invalid (={}) since max_positions={}, "
"skip this example with --skip-invalid-size-inputs-valid-test"
).format(ignored[0], dataset.size(ignored[0]), max_positions)
)
if len(ignored) > 0:
logger.warning(
(
"{} samples have invalid sizes and will be skipped, "
"max_positions={}, first few sample ids={}"
).format(len(ignored), max_positions, ignored[:10])
)
return indices
def filter_paired_dataset_indices_by_size(src_sizes, tgt_sizes, indices, max_sizes):
"""Filter a list of sample indices. Remove those that are longer
than specified in max_sizes.
Args:
indices (np.array): original array of sample indices
max_sizes (int or list[int] or tuple[int]): max sample size,
can be defined separately for src and tgt (then list or tuple)
Returns:
np.array: filtered sample array
list: list of removed indices
"""
if max_sizes is None:
return indices, []
if type(max_sizes) in (int, float):
max_src_size, max_tgt_size = max_sizes, max_sizes
else:
max_src_size, max_tgt_size = max_sizes
if tgt_sizes is None:
ignored = indices[src_sizes[indices] > max_src_size]
else:
ignored = indices[
(src_sizes[indices] > max_src_size) | (tgt_sizes[indices] > max_tgt_size)
]
if len(ignored) > 0:
if tgt_sizes is None:
indices = indices[src_sizes[indices] <= max_src_size]
else:
indices = indices[
(src_sizes[indices] <= max_src_size)
& (tgt_sizes[indices] <= max_tgt_size)
]
return indices, ignored.tolist()
def batch_by_size(
indices,
num_tokens_fn,
num_tokens_vec=None,
max_tokens=None,
max_sentences=None,
required_batch_size_multiple=1,
fixed_shapes=None,
):
"""
Yield mini-batches of indices bucketed by size. Batches may contain
sequences of different lengths.
Args:
indices (List[int]): ordered list of dataset indices
num_tokens_fn (callable): function that returns the number of tokens at
a given index
num_tokens_vec (List[int], optional): precomputed vector of the number
of tokens for each index in indices (to enable faster batch generation)
max_tokens (int, optional): max number of tokens in each batch
(default: None).
max_sentences (int, optional): max number of sentences in each
batch (default: None).
required_batch_size_multiple (int, optional): require batch size to
be less than N or a multiple of N (default: 1).
fixed_shapes (List[Tuple[int, int]], optional): if given, batches will
only be created with the given shapes. *max_sentences* and
*required_batch_size_multiple* will be ignored (default: None).
"""
try:
from fairseq.data.data_utils_fast import (
batch_by_size_fn,
batch_by_size_vec,
batch_fixed_shapes_fast,
)
except ImportError:
raise ImportError(
"Please build Cython components with: "
"`python setup.py build_ext --inplace`"
)
except ValueError:
raise ValueError(
"Please build (or rebuild) Cython components with `python setup.py build_ext --inplace`."
)
# added int() to avoid TypeError: an integer is required
max_tokens = (
int(max_tokens) if max_tokens is not None else -1
)
max_sentences = max_sentences if max_sentences is not None else -1
bsz_mult = required_batch_size_multiple
if not isinstance(indices, np.ndarray):
indices = np.fromiter(indices, dtype=np.int64, count=-1)
if num_tokens_vec is not None and not isinstance(num_tokens_vec, np.ndarray):
num_tokens_vec = np.fromiter(num_tokens_vec, dtype=np.int64, count=-1)
if fixed_shapes is None:
if num_tokens_vec is None:
return batch_by_size_fn(
indices,
num_tokens_fn,
max_tokens,
max_sentences,
bsz_mult,
)
else:
return batch_by_size_vec(
indices,
num_tokens_vec,
max_tokens,
max_sentences,
bsz_mult,
)
else:
fixed_shapes = np.array(fixed_shapes, dtype=np.int64)
sort_order = np.lexsort(
[
fixed_shapes[:, 1].argsort(), # length
fixed_shapes[:, 0].argsort(), # bsz
]
)
fixed_shapes_sorted = fixed_shapes[sort_order]
return batch_fixed_shapes_fast(indices, num_tokens_fn, fixed_shapes_sorted)
def post_process(sentence: str, symbol: str):
if symbol == "sentencepiece":
sentence = sentence.replace(" ", "").replace("\u2581", " ").strip()
elif symbol == "wordpiece":
sentence = sentence.replace(" ", "").replace("_", " ").strip()
elif symbol == "letter":
sentence = sentence.replace(" ", "").replace("|", " ").strip()
elif symbol == "silence":
import re
sentence = sentence.replace("<SIL>", "")
sentence = re.sub(' +', ' ', sentence).strip()
elif symbol == "_EOW":
sentence = sentence.replace(" ", "").replace("_EOW", " ").strip()
elif symbol in {"subword_nmt", "@@ ", "@@"}:
if symbol == "subword_nmt":
symbol = "@@ "
sentence = (sentence + " ").replace(symbol, "").rstrip()
elif symbol == "none":
pass
elif symbol is not None:
raise NotImplementedError(f"Unknown post_process option: {symbol}")
return sentence
def compute_mask_indices(
shape: Tuple[int, int],
padding_mask: Optional[torch.Tensor],
mask_prob: float,
mask_length: int,
mask_type: str = "static",
mask_other: float = 0.0,
min_masks: int = 0,
no_overlap: bool = False,
min_space: int = 0,
) -> np.ndarray:
"""
Computes random mask spans for a given shape
Args:
shape: the the shape for which to compute masks.
should be of size 2 where first element is batch size and 2nd is timesteps
padding_mask: optional padding mask of the same size as shape, which will prevent masking padded elements
mask_prob: probability for each token to be chosen as start of the span to be masked. this will be multiplied by
number of timesteps divided by length of mask span to mask approximately this percentage of all elements.
however due to overlaps, the actual number will be smaller (unless no_overlap is True)
mask_type: how to compute mask lengths
static = fixed size
uniform = sample from uniform distribution [mask_other, mask_length*2]
normal = sample from normal distribution with mean mask_length and stdev mask_other. mask is min 1 element
poisson = sample from possion distribution with lambda = mask length
min_masks: minimum number of masked spans
no_overlap: if false, will switch to an alternative recursive algorithm that prevents spans from overlapping
min_space: only used if no_overlap is True, this is how many elements to keep unmasked between spans
"""
bsz, all_sz = shape
mask = np.full((bsz, all_sz), False)
all_num_mask = int(
# add a random number for probabilistic rounding
mask_prob * all_sz / float(mask_length)
+ np.random.rand()
)
all_num_mask = max(min_masks, all_num_mask)
mask_idcs = []
for i in range(bsz):
if padding_mask is not None:
sz = all_sz - padding_mask[i].long().sum().item()
num_mask = int(
# add a random number for probabilistic rounding
mask_prob * sz / float(mask_length)
+ np.random.rand()
)
num_mask = max(min_masks, num_mask)
else:
sz = all_sz
num_mask = all_num_mask
if mask_type == "static":
lengths = np.full(num_mask, mask_length)
elif mask_type == "uniform":
lengths = np.random.randint(mask_other, mask_length * 2 + 1, size=num_mask)
elif mask_type == "normal":
lengths = np.random.normal(mask_length, mask_other, size=num_mask)
lengths = [max(1, int(round(x))) for x in lengths]
elif mask_type == "poisson":
lengths = np.random.poisson(mask_length, size=num_mask)
lengths = [int(round(x)) for x in lengths]
else:
raise Exception("unknown mask selection " + mask_type)
if sum(lengths) == 0:
lengths[0] = min(mask_length, sz - 1)
if no_overlap:
mask_idc = []
def arrange(s, e, length, keep_length):
span_start = np.random.randint(s, e - length)
mask_idc.extend(span_start + i for i in range(length))
new_parts = []
if span_start - s - min_space >= keep_length:
new_parts.append((s, span_start - min_space + 1))
if e - span_start - keep_length - min_space > keep_length:
new_parts.append((span_start + length + min_space, e))
return new_parts
parts = [(0, sz)]
min_length = min(lengths)
for length in sorted(lengths, reverse=True):
lens = np.fromiter(
(e - s if e - s >= length + min_space else 0 for s, e in parts),
np.int,
)
l_sum = np.sum(lens)
if l_sum == 0:
break
probs = lens / np.sum(lens)
c = np.random.choice(len(parts), p=probs)
s, e = parts.pop(c)
parts.extend(arrange(s, e, length, min_length))
mask_idc = np.asarray(mask_idc)
else:
min_len = min(lengths)
if sz - min_len <= num_mask:
min_len = sz - num_mask - 1
mask_idc = np.random.choice(sz - min_len, num_mask, replace=False)
mask_idc = np.asarray(
[
mask_idc[j] + offset
for j in range(len(mask_idc))
for offset in range(lengths[j])
]
)
mask_idcs.append(np.unique(mask_idc[mask_idc < sz]))
min_len = min([len(m) for m in mask_idcs])
for i, mask_idc in enumerate(mask_idcs):
if len(mask_idc) > min_len:
mask_idc = np.random.choice(mask_idc, min_len, replace=False)
mask[i, mask_idc] = True
return mask
def get_mem_usage():
try:
import psutil
mb = 1024 * 1024
return f"used={psutil.virtual_memory().used / mb}Mb; avail={psutil.virtual_memory().available / mb}Mb"
except ImportError:
return "N/A"
# lens: torch.LongTensor
# returns: torch.BoolTensor
def lengths_to_padding_mask(lens):
bsz, max_lens = lens.size(0), torch.max(lens).item()
mask = torch.arange(max_lens).to(lens.device).view(1, max_lens)
mask = mask.expand(bsz, -1) >= lens.view(bsz, 1).expand(-1, max_lens)
return mask
# lens: torch.LongTensor
# returns: torch.BoolTensor
def lengths_to_mask(lens):
return ~lengths_to_padding_mask(lens)
def get_buckets(sizes, num_buckets):
buckets = np.unique(
np.percentile(
sizes,
np.linspace(0, 100, num_buckets + 1),
interpolation='lower',
)[1:]
)
return buckets
def get_bucketed_sizes(orig_sizes, buckets):
sizes = np.copy(orig_sizes)
assert np.min(sizes) >= 0
start_val = -1
for end_val in buckets:
mask = (sizes > start_val) & (sizes <= end_val)
sizes[mask] = end_val
start_val = end_val
return sizes
def _find_extra_valid_paths(dataset_path: str) -> set:
paths = utils.split_paths(dataset_path)
all_valid_paths = set()
for sub_dir in paths:
contents = PathManager.ls(sub_dir)
valid_paths = [c for c in contents if re.match("valid*[0-9].*", c) is not None]
all_valid_paths |= {os.path.basename(p) for p in valid_paths}
# Remove .bin, .idx etc
roots = {os.path.splitext(p)[0] for p in all_valid_paths}
return roots
def raise_if_valid_subsets_unintentionally_ignored(train_cfg) -> None:
"""Raises if there are paths matching 'valid*[0-9].*' which are not combined or ignored."""
if (
train_cfg.dataset.ignore_unused_valid_subsets
or train_cfg.dataset.combine_valid_subsets
or train_cfg.dataset.disable_validation
or not hasattr(train_cfg.task, "data")
):
return
other_paths = _find_extra_valid_paths(train_cfg.task.data)
specified_subsets = train_cfg.dataset.valid_subset.split(",")
ignored_paths = [p for p in other_paths if p not in specified_subsets]
if ignored_paths:
advice = "Set --combine-val to combine them or --ignore-unused-valid-subsets to ignore them."
msg = f"Valid paths {ignored_paths} will be ignored. {advice}"
raise ValueError(msg)