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# Copyright 2020 The HuggingFace Team. All rights reserved. | |
# | |
# Licensed under the Apache License, Version 2.0 (the "License"); | |
# you may not use this file except in compliance with the License. | |
# You may obtain a copy of the License at | |
# | |
# http://www.apache.org/licenses/LICENSE-2.0 | |
# | |
# Unless required by applicable law or agreed to in writing, software | |
# distributed under the License is distributed on an "AS IS" BASIS, | |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
# See the License for the specific language governing permissions and | |
# limitations under the License. | |
import random | |
import warnings | |
from collections.abc import Mapping | |
from dataclasses import dataclass | |
from random import randint | |
from typing import Any, Callable, Dict, List, NewType, Optional, Tuple, Union | |
import numpy as np | |
from ..models.bert import BertTokenizer, BertTokenizerFast | |
from ..tokenization_utils_base import PreTrainedTokenizerBase | |
from ..utils import PaddingStrategy | |
InputDataClass = NewType("InputDataClass", Any) | |
""" | |
A DataCollator is a function that takes a list of samples from a Dataset and collate them into a batch, as a dictionary | |
of PyTorch/TensorFlow tensors or NumPy arrays. | |
""" | |
DataCollator = NewType("DataCollator", Callable[[List[InputDataClass]], Dict[str, Any]]) | |
class DataCollatorMixin: | |
def __call__(self, features, return_tensors=None): | |
if return_tensors is None: | |
return_tensors = self.return_tensors | |
if return_tensors == "tf": | |
return self.tf_call(features) | |
elif return_tensors == "pt": | |
return self.torch_call(features) | |
elif return_tensors == "np": | |
return self.numpy_call(features) | |
else: | |
raise ValueError(f"Framework '{return_tensors}' not recognized!") | |
def default_data_collator(features: List[InputDataClass], return_tensors="pt") -> Dict[str, Any]: | |
""" | |
Very simple data collator that simply collates batches of dict-like objects and performs special handling for | |
potential keys named: | |
- `label`: handles a single value (int or float) per object | |
- `label_ids`: handles a list of values per object | |
Does not do any additional preprocessing: property names of the input object will be used as corresponding inputs | |
to the model. See glue and ner for example of how it's useful. | |
""" | |
# In this function we'll make the assumption that all `features` in the batch | |
# have the same attributes. | |
# So we will look at the first element as a proxy for what attributes exist | |
# on the whole batch. | |
if return_tensors == "pt": | |
return torch_default_data_collator(features) | |
elif return_tensors == "tf": | |
return tf_default_data_collator(features) | |
elif return_tensors == "np": | |
return numpy_default_data_collator(features) | |
class DefaultDataCollator(DataCollatorMixin): | |
""" | |
Very simple data collator that simply collates batches of dict-like objects and performs special handling for | |
potential keys named: | |
- `label`: handles a single value (int or float) per object | |
- `label_ids`: handles a list of values per object | |
Does not do any additional preprocessing: property names of the input object will be used as corresponding inputs | |
to the model. See glue and ner for example of how it's useful. | |
This is an object (like other data collators) rather than a pure function like default_data_collator. This can be | |
helpful if you need to set a return_tensors value at initialization. | |
Args: | |
return_tensors (`str`, *optional*, defaults to `"pt"`): | |
The type of Tensor to return. Allowable values are "np", "pt" and "tf". | |
""" | |
return_tensors: str = "pt" | |
def __call__(self, features: List[Dict[str, Any]], return_tensors=None) -> Dict[str, Any]: | |
if return_tensors is None: | |
return_tensors = self.return_tensors | |
return default_data_collator(features, return_tensors) | |
def torch_default_data_collator(features: List[InputDataClass]) -> Dict[str, Any]: | |
import torch | |
if not isinstance(features[0], Mapping): | |
features = [vars(f) for f in features] | |
first = features[0] | |
batch = {} | |
# Special handling for labels. | |
# Ensure that tensor is created with the correct type | |
# (it should be automatically the case, but let's make sure of it.) | |
if "label" in first and first["label"] is not None: | |
label = first["label"].item() if isinstance(first["label"], torch.Tensor) else first["label"] | |
dtype = torch.long if isinstance(label, int) else torch.float | |
batch["labels"] = torch.tensor([f["label"] for f in features], dtype=dtype) | |
elif "label_ids" in first and first["label_ids"] is not None: | |
if isinstance(first["label_ids"], torch.Tensor): | |
batch["labels"] = torch.stack([f["label_ids"] for f in features]) | |
else: | |
dtype = torch.long if type(first["label_ids"][0]) is int else torch.float | |
batch["labels"] = torch.tensor([f["label_ids"] for f in features], dtype=dtype) | |
# Handling of all other possible keys. | |
# Again, we will use the first element to figure out which key/values are not None for this model. | |
for k, v in first.items(): | |
if k not in ("label", "label_ids") and v is not None and not isinstance(v, str): | |
if isinstance(v, torch.Tensor): | |
batch[k] = torch.stack([f[k] for f in features]) | |
elif isinstance(v, np.ndarray): | |
batch[k] = torch.tensor(np.stack([f[k] for f in features])) | |
else: | |
batch[k] = torch.tensor([f[k] for f in features]) | |
return batch | |
def tf_default_data_collator(features: List[InputDataClass]) -> Dict[str, Any]: | |
import tensorflow as tf | |
if not isinstance(features[0], Mapping): | |
features = [vars(f) for f in features] | |
first = features[0] | |
batch = {} | |
# Special handling for labels. | |
# Ensure that tensor is created with the correct type | |
# (it should be automatically the case, but let's make sure of it.) | |
if "label" in first and first["label"] is not None: | |
label_col_name = "label" | |
elif "label_ids" in first and first["label_ids"] is not None: | |
label_col_name = "label_ids" | |
elif "labels" in first and first["labels"] is not None: | |
label_col_name = "labels" | |
else: | |
label_col_name = None | |
if label_col_name is not None: | |
if isinstance(first[label_col_name], tf.Tensor): | |
dtype = tf.int64 if first[label_col_name].dtype.is_integer else tf.float32 | |
elif isinstance(first[label_col_name], np.ndarray) or isinstance(first[label_col_name], np.generic): | |
dtype = tf.int64 if np.issubdtype(first[label_col_name].dtype, np.integer) else tf.float32 | |
elif isinstance(first[label_col_name], (tuple, list)): | |
dtype = tf.int64 if isinstance(first[label_col_name][0], int) else tf.float32 | |
else: | |
dtype = tf.int64 if isinstance(first[label_col_name], int) else tf.float32 | |
batch["labels"] = tf.convert_to_tensor([f[label_col_name] for f in features], dtype=dtype) | |
# Handling of all other possible keys. | |
# Again, we will use the first element to figure out which key/values are not None for this model. | |
for k, v in first.items(): | |
if k not in ("label", "label_ids", "labels") and v is not None and not isinstance(v, str): | |
if isinstance(v, (tf.Tensor, np.ndarray)): | |
batch[k] = tf.stack([f[k] for f in features]) | |
else: | |
batch[k] = tf.convert_to_tensor([f[k] for f in features]) | |
return batch | |
def numpy_default_data_collator(features: List[InputDataClass]) -> Dict[str, Any]: | |
if not isinstance(features[0], Mapping): | |
features = [vars(f) for f in features] | |
first = features[0] | |
batch = {} | |
# Special handling for labels. | |
# Ensure that tensor is created with the correct type | |
# (it should be automatically the case, but let's make sure of it.) | |
if "label" in first and first["label"] is not None: | |
label = first["label"].item() if isinstance(first["label"], np.ndarray) else first["label"] | |
dtype = np.int64 if isinstance(label, int) else np.float32 | |
batch["labels"] = np.array([f["label"] for f in features], dtype=dtype) | |
elif "label_ids" in first and first["label_ids"] is not None: | |
if isinstance(first["label_ids"], np.ndarray): | |
batch["labels"] = np.stack([f["label_ids"] for f in features]) | |
else: | |
dtype = np.int64 if type(first["label_ids"][0]) is int else np.float32 | |
batch["labels"] = np.array([f["label_ids"] for f in features], dtype=dtype) | |
# Handling of all other possible keys. | |
# Again, we will use the first element to figure out which key/values are not None for this model. | |
for k, v in first.items(): | |
if k not in ("label", "label_ids") and v is not None and not isinstance(v, str): | |
if isinstance(v, np.ndarray): | |
batch[k] = np.stack([f[k] for f in features]) | |
else: | |
batch[k] = np.array([f[k] for f in features]) | |
return batch | |
class DataCollatorWithPadding: | |
""" | |
Data collator that will dynamically pad the inputs received. | |
Args: | |
tokenizer ([`PreTrainedTokenizer`] or [`PreTrainedTokenizerFast`]): | |
The tokenizer used for encoding the data. | |
padding (`bool`, `str` or [`~utils.PaddingStrategy`], *optional*, defaults to `True`): | |
Select a strategy to pad the returned sequences (according to the model's padding side and padding index) | |
among: | |
- `True` or `'longest'` (default): Pad to the longest sequence in the batch (or no padding if only a single | |
sequence is provided). | |
- `'max_length'`: Pad to a maximum length specified with the argument `max_length` or to the maximum | |
acceptable input length for the model if that argument is not provided. | |
- `False` or `'do_not_pad'`: No padding (i.e., can output a batch with sequences of different lengths). | |
max_length (`int`, *optional*): | |
Maximum length of the returned list and optionally padding length (see above). | |
pad_to_multiple_of (`int`, *optional*): | |
If set will pad the sequence to a multiple of the provided value. | |
This is especially useful to enable the use of Tensor Cores on NVIDIA hardware with compute capability >= | |
7.5 (Volta). | |
return_tensors (`str`, *optional*, defaults to `"pt"`): | |
The type of Tensor to return. Allowable values are "np", "pt" and "tf". | |
""" | |
tokenizer: PreTrainedTokenizerBase | |
padding: Union[bool, str, PaddingStrategy] = True | |
max_length: Optional[int] = None | |
pad_to_multiple_of: Optional[int] = None | |
return_tensors: str = "pt" | |
def __call__(self, features: List[Dict[str, Any]]) -> Dict[str, Any]: | |
batch = self.tokenizer.pad( | |
features, | |
padding=self.padding, | |
max_length=self.max_length, | |
pad_to_multiple_of=self.pad_to_multiple_of, | |
return_tensors=self.return_tensors, | |
) | |
if "label" in batch: | |
batch["labels"] = batch["label"] | |
del batch["label"] | |
if "label_ids" in batch: | |
batch["labels"] = batch["label_ids"] | |
del batch["label_ids"] | |
return batch | |
class DataCollatorForTokenClassification(DataCollatorMixin): | |
""" | |
Data collator that will dynamically pad the inputs received, as well as the labels. | |
Args: | |
tokenizer ([`PreTrainedTokenizer`] or [`PreTrainedTokenizerFast`]): | |
The tokenizer used for encoding the data. | |
padding (`bool`, `str` or [`~utils.PaddingStrategy`], *optional*, defaults to `True`): | |
Select a strategy to pad the returned sequences (according to the model's padding side and padding index) | |
among: | |
- `True` or `'longest'` (default): Pad to the longest sequence in the batch (or no padding if only a single | |
sequence is provided). | |
- `'max_length'`: Pad to a maximum length specified with the argument `max_length` or to the maximum | |
acceptable input length for the model if that argument is not provided. | |
- `False` or `'do_not_pad'`: No padding (i.e., can output a batch with sequences of different lengths). | |
max_length (`int`, *optional*): | |
Maximum length of the returned list and optionally padding length (see above). | |
pad_to_multiple_of (`int`, *optional*): | |
If set will pad the sequence to a multiple of the provided value. | |
This is especially useful to enable the use of Tensor Cores on NVIDIA hardware with compute capability >= | |
7.5 (Volta). | |
label_pad_token_id (`int`, *optional*, defaults to -100): | |
The id to use when padding the labels (-100 will be automatically ignore by PyTorch loss functions). | |
return_tensors (`str`, *optional*, defaults to `"pt"`): | |
The type of Tensor to return. Allowable values are "np", "pt" and "tf". | |
""" | |
tokenizer: PreTrainedTokenizerBase | |
padding: Union[bool, str, PaddingStrategy] = True | |
max_length: Optional[int] = None | |
pad_to_multiple_of: Optional[int] = None | |
label_pad_token_id: int = -100 | |
return_tensors: str = "pt" | |
def torch_call(self, features): | |
import torch | |
label_name = "label" if "label" in features[0].keys() else "labels" | |
labels = [feature[label_name] for feature in features] if label_name in features[0].keys() else None | |
no_labels_features = [{k: v for k, v in feature.items() if k != label_name} for feature in features] | |
batch = self.tokenizer.pad( | |
no_labels_features, | |
padding=self.padding, | |
max_length=self.max_length, | |
pad_to_multiple_of=self.pad_to_multiple_of, | |
return_tensors="pt", | |
) | |
if labels is None: | |
return batch | |
sequence_length = batch["input_ids"].shape[1] | |
padding_side = self.tokenizer.padding_side | |
def to_list(tensor_or_iterable): | |
if isinstance(tensor_or_iterable, torch.Tensor): | |
return tensor_or_iterable.tolist() | |
return list(tensor_or_iterable) | |
if padding_side == "right": | |
batch[label_name] = [ | |
to_list(label) + [self.label_pad_token_id] * (sequence_length - len(label)) for label in labels | |
] | |
else: | |
batch[label_name] = [ | |
[self.label_pad_token_id] * (sequence_length - len(label)) + to_list(label) for label in labels | |
] | |
batch[label_name] = torch.tensor(batch[label_name], dtype=torch.int64) | |
return batch | |
def tf_call(self, features): | |
import tensorflow as tf | |
label_name = "label" if "label" in features[0].keys() else "labels" | |
labels = [feature[label_name] for feature in features] if label_name in features[0].keys() else None | |
batch = self.tokenizer.pad( | |
features, | |
padding=self.padding, | |
max_length=self.max_length, | |
pad_to_multiple_of=self.pad_to_multiple_of, | |
# Conversion to tensors will fail if we have labels as they are not of the same length yet. | |
return_tensors="tf" if labels is None else None, | |
) | |
if labels is None: | |
return batch | |
sequence_length = tf.convert_to_tensor(batch["input_ids"]).shape[1] | |
padding_side = self.tokenizer.padding_side | |
if padding_side == "right": | |
batch["labels"] = [ | |
list(label) + [self.label_pad_token_id] * (sequence_length - len(label)) for label in labels | |
] | |
else: | |
batch["labels"] = [ | |
[self.label_pad_token_id] * (sequence_length - len(label)) + list(label) for label in labels | |
] | |
batch = {k: tf.convert_to_tensor(v, dtype=tf.int64) for k, v in batch.items()} | |
return batch | |
def numpy_call(self, features): | |
label_name = "label" if "label" in features[0].keys() else "labels" | |
labels = [feature[label_name] for feature in features] if label_name in features[0].keys() else None | |
batch = self.tokenizer.pad( | |
features, | |
padding=self.padding, | |
max_length=self.max_length, | |
pad_to_multiple_of=self.pad_to_multiple_of, | |
# Conversion to tensors will fail if we have labels as they are not of the same length yet. | |
return_tensors="np" if labels is None else None, | |
) | |
if labels is None: | |
return batch | |
sequence_length = np.array(batch["input_ids"]).shape[1] | |
padding_side = self.tokenizer.padding_side | |
if padding_side == "right": | |
batch["labels"] = [ | |
list(label) + [self.label_pad_token_id] * (sequence_length - len(label)) for label in labels | |
] | |
else: | |
batch["labels"] = [ | |
[self.label_pad_token_id] * (sequence_length - len(label)) + list(label) for label in labels | |
] | |
batch = {k: np.array(v, dtype=np.int64) for k, v in batch.items()} | |
return batch | |
def _torch_collate_batch(examples, tokenizer, pad_to_multiple_of: Optional[int] = None): | |
"""Collate `examples` into a batch, using the information in `tokenizer` for padding if necessary.""" | |
import torch | |
# Tensorize if necessary. | |
if isinstance(examples[0], (list, tuple, np.ndarray)): | |
examples = [torch.tensor(e, dtype=torch.long) for e in examples] | |
length_of_first = examples[0].size(0) | |
# Check if padding is necessary. | |
are_tensors_same_length = all(x.size(0) == length_of_first for x in examples) | |
if are_tensors_same_length and (pad_to_multiple_of is None or length_of_first % pad_to_multiple_of == 0): | |
return torch.stack(examples, dim=0) | |
# If yes, check if we have a `pad_token`. | |
if tokenizer._pad_token is None: | |
raise ValueError( | |
"You are attempting to pad samples but the tokenizer you are using" | |
f" ({tokenizer.__class__.__name__}) does not have a pad token." | |
) | |
# Creating the full tensor and filling it with our data. | |
max_length = max(x.size(0) for x in examples) | |
if pad_to_multiple_of is not None and (max_length % pad_to_multiple_of != 0): | |
max_length = ((max_length // pad_to_multiple_of) + 1) * pad_to_multiple_of | |
result = examples[0].new_full([len(examples), max_length], tokenizer.pad_token_id) | |
for i, example in enumerate(examples): | |
if tokenizer.padding_side == "right": | |
result[i, : example.shape[0]] = example | |
else: | |
result[i, -example.shape[0] :] = example | |
return result | |
def _tf_collate_batch(examples, tokenizer, pad_to_multiple_of: Optional[int] = None): | |
import tensorflow as tf | |
"""Collate `examples` into a batch, using the information in `tokenizer` for padding if necessary.""" | |
# Tensorize if necessary. | |
if isinstance(examples[0], (list, tuple)): | |
examples = [tf.convert_to_tensor(e, dtype=tf.int64) for e in examples] | |
# Check if padding is necessary. | |
length_of_first = len(examples[0]) | |
are_tensors_same_length = all(len(x) == length_of_first for x in examples) | |
if are_tensors_same_length and (pad_to_multiple_of is None or length_of_first % pad_to_multiple_of == 0): | |
return tf.stack(examples, axis=0) | |
# If yes, check if we have a `pad_token`. | |
if tokenizer._pad_token is None: | |
raise ValueError( | |
"You are attempting to pad samples but the tokenizer you are using" | |
f" ({tokenizer.__class__.__name__}) does not have a pad token." | |
) | |
# Creating the full tensor and filling it with our data. | |
max_length = max(len(x) for x in examples) | |
if pad_to_multiple_of is not None and (max_length % pad_to_multiple_of != 0): | |
max_length = ((max_length // pad_to_multiple_of) + 1) * pad_to_multiple_of | |
# result = examples[0].new_full([len(examples), max_length], tokenizer.pad_token_id) | |
result = [] | |
rank = tf.rank(examples[0]) | |
paddings = np.zeros((rank, 2), dtype=np.int32) | |
for example in examples: | |
if tokenizer.padding_side == "right": | |
paddings[0, 1] = max_length - len(example) | |
else: | |
paddings[0, 0] = max_length - len(example) | |
result.append(tf.pad(example, paddings, constant_values=tokenizer.pad_token_id)) | |
return tf.stack(result, axis=0) | |
def _numpy_collate_batch(examples, tokenizer, pad_to_multiple_of: Optional[int] = None): | |
"""Collate `examples` into a batch, using the information in `tokenizer` for padding if necessary.""" | |
# Tensorize if necessary. | |
if isinstance(examples[0], (list, tuple)): | |
examples = [np.array(e, dtype=np.int64) for e in examples] | |
# Check if padding is necessary. | |
length_of_first = len(examples[0]) | |
are_tensors_same_length = all(len(x) == length_of_first for x in examples) | |
if are_tensors_same_length and (pad_to_multiple_of is None or length_of_first % pad_to_multiple_of == 0): | |
return np.stack(examples, axis=0) | |
# If yes, check if we have a `pad_token`. | |
if tokenizer._pad_token is None: | |
raise ValueError( | |
"You are attempting to pad samples but the tokenizer you are using" | |
f" ({tokenizer.__class__.__name__}) does not have a pad token." | |
) | |
# Creating the full tensor and filling it with our data. | |
max_length = max(len(x) for x in examples) | |
if pad_to_multiple_of is not None and (max_length % pad_to_multiple_of != 0): | |
max_length = ((max_length // pad_to_multiple_of) + 1) * pad_to_multiple_of | |
result = np.full(shape=(len(examples), max_length), fill_value=tokenizer.pad_token_id, dtype=examples[0].dtype) | |
for i, example in enumerate(examples): | |
if tokenizer.padding_side == "right": | |
result[i, : example.shape[0]] = example | |
else: | |
result[i, -example.shape[0] :] = example | |
return result | |
def tolist(x): | |
if isinstance(x, list): | |
return x | |
elif hasattr(x, "numpy"): # Checks for TF tensors without needing the import | |
x = x.numpy() | |
return x.tolist() | |
class DataCollatorForSeq2Seq: | |
""" | |
Data collator that will dynamically pad the inputs received, as well as the labels. | |
Args: | |
tokenizer ([`PreTrainedTokenizer`] or [`PreTrainedTokenizerFast`]): | |
The tokenizer used for encoding the data. | |
model ([`PreTrainedModel`], *optional*): | |
The model that is being trained. If set and has the *prepare_decoder_input_ids_from_labels*, use it to | |
prepare the *decoder_input_ids* | |
This is useful when using *label_smoothing* to avoid calculating loss twice. | |
padding (`bool`, `str` or [`~utils.PaddingStrategy`], *optional*, defaults to `True`): | |
Select a strategy to pad the returned sequences (according to the model's padding side and padding index) | |
among: | |
- `True` or `'longest'` (default): Pad to the longest sequence in the batch (or no padding if only a single | |
sequence is provided). | |
- `'max_length'`: Pad to a maximum length specified with the argument `max_length` or to the maximum | |
acceptable input length for the model if that argument is not provided. | |
- `False` or `'do_not_pad'`: No padding (i.e., can output a batch with sequences of different lengths). | |
max_length (`int`, *optional*): | |
Maximum length of the returned list and optionally padding length (see above). | |
pad_to_multiple_of (`int`, *optional*): | |
If set will pad the sequence to a multiple of the provided value. | |
This is especially useful to enable the use of Tensor Cores on NVIDIA hardware with compute capability >= | |
7.5 (Volta). | |
label_pad_token_id (`int`, *optional*, defaults to -100): | |
The id to use when padding the labels (-100 will be automatically ignored by PyTorch loss functions). | |
return_tensors (`str`, *optional*, defaults to `"pt"`): | |
The type of Tensor to return. Allowable values are "np", "pt" and "tf". | |
""" | |
tokenizer: PreTrainedTokenizerBase | |
model: Optional[Any] = None | |
padding: Union[bool, str, PaddingStrategy] = True | |
max_length: Optional[int] = None | |
pad_to_multiple_of: Optional[int] = None | |
label_pad_token_id: int = -100 | |
return_tensors: str = "pt" | |
def __call__(self, features, return_tensors=None): | |
if return_tensors is None: | |
return_tensors = self.return_tensors | |
labels = [feature["labels"] for feature in features] if "labels" in features[0].keys() else None | |
# We have to pad the labels before calling `tokenizer.pad` as this method won't pad them and needs them of the | |
# same length to return tensors. | |
if labels is not None: | |
max_label_length = max(len(l) for l in labels) | |
if self.pad_to_multiple_of is not None: | |
max_label_length = ( | |
(max_label_length + self.pad_to_multiple_of - 1) | |
// self.pad_to_multiple_of | |
* self.pad_to_multiple_of | |
) | |
padding_side = self.tokenizer.padding_side | |
for feature in features: | |
remainder = [self.label_pad_token_id] * (max_label_length - len(feature["labels"])) | |
if isinstance(feature["labels"], list): | |
feature["labels"] = ( | |
feature["labels"] + remainder if padding_side == "right" else remainder + feature["labels"] | |
) | |
elif padding_side == "right": | |
feature["labels"] = np.concatenate([feature["labels"], remainder]).astype(np.int64) | |
else: | |
feature["labels"] = np.concatenate([remainder, feature["labels"]]).astype(np.int64) | |
features = self.tokenizer.pad( | |
features, | |
padding=self.padding, | |
max_length=self.max_length, | |
pad_to_multiple_of=self.pad_to_multiple_of, | |
return_tensors=return_tensors, | |
) | |
# prepare decoder_input_ids | |
if ( | |
labels is not None | |
and self.model is not None | |
and hasattr(self.model, "prepare_decoder_input_ids_from_labels") | |
): | |
decoder_input_ids = self.model.prepare_decoder_input_ids_from_labels(labels=features["labels"]) | |
features["decoder_input_ids"] = decoder_input_ids | |
return features | |
class DataCollatorForLanguageModeling(DataCollatorMixin): | |
""" | |
Data collator used for language modeling. Inputs are dynamically padded to the maximum length of a batch if they | |
are not all of the same length. | |
Args: | |
tokenizer ([`PreTrainedTokenizer`] or [`PreTrainedTokenizerFast`]): | |
The tokenizer used for encoding the data. | |
mlm (`bool`, *optional*, defaults to `True`): | |
Whether or not to use masked language modeling. If set to `False`, the labels are the same as the inputs | |
with the padding tokens ignored (by setting them to -100). Otherwise, the labels are -100 for non-masked | |
tokens and the value to predict for the masked token. | |
mlm_probability (`float`, *optional*, defaults to 0.15): | |
The probability with which to (randomly) mask tokens in the input, when `mlm` is set to `True`. | |
pad_to_multiple_of (`int`, *optional*): | |
If set will pad the sequence to a multiple of the provided value. | |
return_tensors (`str`): | |
The type of Tensor to return. Allowable values are "np", "pt" and "tf". | |
<Tip> | |
For best performance, this data collator should be used with a dataset having items that are dictionaries or | |
BatchEncoding, with the `"special_tokens_mask"` key, as returned by a [`PreTrainedTokenizer`] or a | |
[`PreTrainedTokenizerFast`] with the argument `return_special_tokens_mask=True`. | |
</Tip>""" | |
tokenizer: PreTrainedTokenizerBase | |
mlm: bool = True | |
mlm_probability: float = 0.15 | |
pad_to_multiple_of: Optional[int] = None | |
tf_experimental_compile: bool = False | |
return_tensors: str = "pt" | |
def __post_init__(self): | |
if self.mlm and self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for masked language modeling. " | |
"You should pass `mlm=False` to train on causal language modeling instead." | |
) | |
if self.tf_experimental_compile: | |
import tensorflow as tf | |
self.tf_mask_tokens = tf.function(self.tf_mask_tokens, jit_compile=True) | |
def tf_bernoulli(shape, probability): | |
import tensorflow as tf | |
prob_matrix = tf.fill(shape, probability) | |
return tf.cast(prob_matrix - tf.random.uniform(shape, 0, 1) >= 0, tf.bool) | |
def tf_mask_tokens( | |
self, inputs: Any, vocab_size, mask_token_id, special_tokens_mask: Optional[Any] = None | |
) -> Tuple[Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. | |
""" | |
import tensorflow as tf | |
mask_token_id = tf.cast(mask_token_id, inputs.dtype) | |
input_shape = tf.shape(inputs) | |
# 1 for a special token, 0 for a normal token in the special tokens mask | |
# We sample a few tokens in each sequence for MLM training (with probability `self.mlm_probability`) | |
masked_indices = self.tf_bernoulli(input_shape, self.mlm_probability) & ~special_tokens_mask | |
# Replace unmasked indices with -100 in the labels since we only compute loss on masked tokens | |
labels = tf.where(masked_indices, inputs, -100) | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = self.tf_bernoulli(input_shape, 0.8) & masked_indices | |
inputs = tf.where(indices_replaced, mask_token_id, inputs) | |
# 10% of the time, we replace masked input tokens with random word | |
indices_random = self.tf_bernoulli(input_shape, 0.1) & masked_indices & ~indices_replaced | |
random_words = tf.random.uniform(input_shape, maxval=vocab_size, dtype=inputs.dtype) | |
inputs = tf.where(indices_random, random_words, inputs) | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels | |
def tf_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
import tensorflow as tf | |
# Handle dict or lists with proper padding and conversion to tensor. | |
if isinstance(examples[0], Mapping): | |
batch = self.tokenizer.pad(examples, return_tensors="tf", pad_to_multiple_of=self.pad_to_multiple_of) | |
else: | |
batch = { | |
"input_ids": _tf_collate_batch(examples, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
} | |
# If special token mask has been preprocessed, pop it from the dict. | |
special_tokens_mask = batch.pop("special_tokens_mask", None) | |
if self.mlm: | |
if special_tokens_mask is None: | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) | |
for val in batch["input_ids"].numpy().tolist() | |
] | |
# Cannot directly create as bool | |
special_tokens_mask = tf.cast(tf.convert_to_tensor(special_tokens_mask, dtype=tf.int64), tf.bool) | |
else: | |
special_tokens_mask = tf.cast(special_tokens_mask, tf.bool) | |
batch["input_ids"], batch["labels"] = self.tf_mask_tokens( | |
tf.cast(batch["input_ids"], tf.int64), | |
special_tokens_mask=special_tokens_mask, | |
mask_token_id=self.tokenizer.mask_token_id, | |
vocab_size=len(self.tokenizer), | |
) | |
else: | |
labels = batch["input_ids"] | |
if self.tokenizer.pad_token_id is not None: | |
# Replace self.tokenizer.pad_token_id with -100 | |
labels = tf.where(labels == self.tokenizer.pad_token_id, -100, labels) | |
else: | |
labels = tf.identity(labels) # Makes a copy, just in case | |
batch["labels"] = labels | |
return batch | |
def torch_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
# Handle dict or lists with proper padding and conversion to tensor. | |
if isinstance(examples[0], Mapping): | |
batch = self.tokenizer.pad(examples, return_tensors="pt", pad_to_multiple_of=self.pad_to_multiple_of) | |
else: | |
batch = { | |
"input_ids": _torch_collate_batch(examples, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
} | |
# If special token mask has been preprocessed, pop it from the dict. | |
special_tokens_mask = batch.pop("special_tokens_mask", None) | |
if self.mlm: | |
batch["input_ids"], batch["labels"] = self.torch_mask_tokens( | |
batch["input_ids"], special_tokens_mask=special_tokens_mask | |
) | |
else: | |
labels = batch["input_ids"].clone() | |
if self.tokenizer.pad_token_id is not None: | |
labels[labels == self.tokenizer.pad_token_id] = -100 | |
batch["labels"] = labels | |
return batch | |
def torch_mask_tokens(self, inputs: Any, special_tokens_mask: Optional[Any] = None) -> Tuple[Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. | |
""" | |
import torch | |
labels = inputs.clone() | |
# We sample a few tokens in each sequence for MLM training (with probability `self.mlm_probability`) | |
probability_matrix = torch.full(labels.shape, self.mlm_probability) | |
if special_tokens_mask is None: | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist() | |
] | |
special_tokens_mask = torch.tensor(special_tokens_mask, dtype=torch.bool) | |
else: | |
special_tokens_mask = special_tokens_mask.bool() | |
probability_matrix.masked_fill_(special_tokens_mask, value=0.0) | |
masked_indices = torch.bernoulli(probability_matrix).bool() | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = torch.bernoulli(torch.full(labels.shape, 0.8)).bool() & masked_indices | |
inputs[indices_replaced] = self.tokenizer.convert_tokens_to_ids(self.tokenizer.mask_token) | |
# 10% of the time, we replace masked input tokens with random word | |
indices_random = torch.bernoulli(torch.full(labels.shape, 0.5)).bool() & masked_indices & ~indices_replaced | |
random_words = torch.randint(len(self.tokenizer), labels.shape, dtype=torch.long) | |
inputs[indices_random] = random_words[indices_random] | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels | |
def numpy_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
# Handle dict or lists with proper padding and conversion to tensor. | |
if isinstance(examples[0], Mapping): | |
batch = self.tokenizer.pad(examples, return_tensors="np", pad_to_multiple_of=self.pad_to_multiple_of) | |
else: | |
batch = { | |
"input_ids": _numpy_collate_batch(examples, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
} | |
# If special token mask has been preprocessed, pop it from the dict. | |
special_tokens_mask = batch.pop("special_tokens_mask", None) | |
if self.mlm: | |
batch["input_ids"], batch["labels"] = self.numpy_mask_tokens( | |
batch["input_ids"], special_tokens_mask=special_tokens_mask | |
) | |
else: | |
labels = np.copy(batch["input_ids"]) | |
if self.tokenizer.pad_token_id is not None: | |
labels[labels == self.tokenizer.pad_token_id] = -100 | |
batch["labels"] = labels | |
return batch | |
def numpy_mask_tokens(self, inputs: Any, special_tokens_mask: Optional[Any] = None) -> Tuple[Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. | |
""" | |
labels = np.copy(inputs) | |
# We sample a few tokens in each sequence for MLM training (with probability `self.mlm_probability`) | |
probability_matrix = np.full(labels.shape, self.mlm_probability) | |
if special_tokens_mask is None: | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist() | |
] | |
special_tokens_mask = np.array(special_tokens_mask, dtype=bool) | |
else: | |
special_tokens_mask = special_tokens_mask.astype(bool) | |
probability_matrix[special_tokens_mask] = 0 | |
# Numpy doesn't have bernoulli, so we use a binomial with 1 trial | |
masked_indices = np.random.binomial(1, probability_matrix, size=probability_matrix.shape).astype(bool) | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = np.random.binomial(1, 0.8, size=labels.shape).astype(bool) & masked_indices | |
inputs[indices_replaced] = self.tokenizer.mask_token_id | |
# 10% of the time, we replace masked input tokens with random word | |
# indices_random = torch.bernoulli(torch.full(labels.shape, 0.5)).bool() & masked_indices & ~indices_replaced | |
indices_random = ( | |
np.random.binomial(1, 0.5, size=labels.shape).astype(bool) & masked_indices & ~indices_replaced | |
) | |
random_words = np.random.randint( | |
low=0, high=len(self.tokenizer), size=np.count_nonzero(indices_random), dtype=np.int64 | |
) | |
inputs[indices_random] = random_words | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels | |
class DataCollatorForWholeWordMask(DataCollatorForLanguageModeling): | |
""" | |
Data collator used for language modeling that masks entire words. | |
- collates batches of tensors, honoring their tokenizer's pad_token | |
- preprocesses batches for masked language modeling | |
<Tip> | |
This collator relies on details of the implementation of subword tokenization by [`BertTokenizer`], specifically | |
that subword tokens are prefixed with *##*. For tokenizers that do not adhere to this scheme, this collator will | |
produce an output that is roughly equivalent to [`.DataCollatorForLanguageModeling`]. | |
</Tip>""" | |
def torch_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
if isinstance(examples[0], Mapping): | |
input_ids = [e["input_ids"] for e in examples] | |
else: | |
input_ids = examples | |
examples = [{"input_ids": e} for e in examples] | |
batch_input = _torch_collate_batch(input_ids, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
mask_labels = [] | |
for e in examples: | |
ref_tokens = [] | |
for id in tolist(e["input_ids"]): | |
token = self.tokenizer._convert_id_to_token(id) | |
ref_tokens.append(token) | |
# For Chinese tokens, we need extra inf to mark sub-word, e.g [喜,欢]-> [喜,##欢] | |
if "chinese_ref" in e: | |
ref_pos = tolist(e["chinese_ref"]) | |
len_seq = len(e["input_ids"]) | |
for i in range(len_seq): | |
if i in ref_pos: | |
ref_tokens[i] = "##" + ref_tokens[i] | |
mask_labels.append(self._whole_word_mask(ref_tokens)) | |
batch_mask = _torch_collate_batch(mask_labels, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
inputs, labels = self.torch_mask_tokens(batch_input, batch_mask) | |
return {"input_ids": inputs, "labels": labels} | |
def tf_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
import tensorflow as tf | |
if isinstance(examples[0], Mapping): | |
input_ids = [e["input_ids"] for e in examples] | |
else: | |
input_ids = examples | |
examples = [{"input_ids": e} for e in examples] | |
batch_input = _tf_collate_batch(input_ids, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
mask_labels = [] | |
for e in examples: | |
ref_tokens = [] | |
for id in tolist(e["input_ids"]): | |
token = self.tokenizer._convert_id_to_token(id) | |
ref_tokens.append(token) | |
# For Chinese tokens, we need extra inf to mark sub-word, e.g [喜,欢]-> [喜,##欢] | |
if "chinese_ref" in e: | |
ref_pos = tolist(e["chinese_ref"]) | |
len_seq = len(e["input_ids"]) | |
for i in range(len_seq): | |
if i in ref_pos: | |
ref_tokens[i] = "##" + ref_tokens[i] | |
mask_labels.append(self._whole_word_mask(ref_tokens)) | |
batch_mask = _tf_collate_batch(mask_labels, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
inputs, labels = self.tf_mask_tokens(tf.cast(batch_input, tf.int64), batch_mask) | |
return {"input_ids": inputs, "labels": labels} | |
def numpy_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
if isinstance(examples[0], Mapping): | |
input_ids = [e["input_ids"] for e in examples] | |
else: | |
input_ids = examples | |
examples = [{"input_ids": e} for e in examples] | |
batch_input = _numpy_collate_batch(input_ids, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
mask_labels = [] | |
for e in examples: | |
ref_tokens = [] | |
for id in tolist(e["input_ids"]): | |
token = self.tokenizer._convert_id_to_token(id) | |
ref_tokens.append(token) | |
# For Chinese tokens, we need extra inf to mark sub-word, e.g [喜,欢]-> [喜,##欢] | |
if "chinese_ref" in e: | |
ref_pos = tolist(e["chinese_ref"]) | |
len_seq = len(e["input_ids"]) | |
for i in range(len_seq): | |
if i in ref_pos: | |
ref_tokens[i] = "##" + ref_tokens[i] | |
mask_labels.append(self._whole_word_mask(ref_tokens)) | |
batch_mask = _numpy_collate_batch(mask_labels, self.tokenizer, pad_to_multiple_of=self.pad_to_multiple_of) | |
inputs, labels = self.numpy_mask_tokens(batch_input, batch_mask) | |
return {"input_ids": inputs, "labels": labels} | |
def _whole_word_mask(self, input_tokens: List[str], max_predictions=512): | |
""" | |
Get 0/1 labels for masked tokens with whole word mask proxy | |
""" | |
if not isinstance(self.tokenizer, (BertTokenizer, BertTokenizerFast)): | |
warnings.warn( | |
"DataCollatorForWholeWordMask is only suitable for BertTokenizer-like tokenizers. " | |
"Please refer to the documentation for more information." | |
) | |
cand_indexes = [] | |
for i, token in enumerate(input_tokens): | |
if token == "[CLS]" or token == "[SEP]": | |
continue | |
if len(cand_indexes) >= 1 and token.startswith("##"): | |
cand_indexes[-1].append(i) | |
else: | |
cand_indexes.append([i]) | |
random.shuffle(cand_indexes) | |
num_to_predict = min(max_predictions, max(1, int(round(len(input_tokens) * self.mlm_probability)))) | |
masked_lms = [] | |
covered_indexes = set() | |
for index_set in cand_indexes: | |
if len(masked_lms) >= num_to_predict: | |
break | |
# If adding a whole-word mask would exceed the maximum number of | |
# predictions, then just skip this candidate. | |
if len(masked_lms) + len(index_set) > num_to_predict: | |
continue | |
is_any_index_covered = False | |
for index in index_set: | |
if index in covered_indexes: | |
is_any_index_covered = True | |
break | |
if is_any_index_covered: | |
continue | |
for index in index_set: | |
covered_indexes.add(index) | |
masked_lms.append(index) | |
if len(covered_indexes) != len(masked_lms): | |
raise ValueError("Length of covered_indexes is not equal to length of masked_lms.") | |
mask_labels = [1 if i in covered_indexes else 0 for i in range(len(input_tokens))] | |
return mask_labels | |
def torch_mask_tokens(self, inputs: Any, mask_labels: Any) -> Tuple[Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. Set | |
'mask_labels' means we use whole word mask (wwm), we directly mask idxs according to it's ref. | |
""" | |
import torch | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for masked language modeling. Remove the" | |
" --mlm flag if you want to use this tokenizer." | |
) | |
labels = inputs.clone() | |
# We sample a few tokens in each sequence for masked-LM training (with probability args.mlm_probability defaults to 0.15 in Bert/RoBERTa) | |
probability_matrix = mask_labels | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist() | |
] | |
probability_matrix.masked_fill_(torch.tensor(special_tokens_mask, dtype=torch.bool), value=0.0) | |
if self.tokenizer._pad_token is not None: | |
padding_mask = labels.eq(self.tokenizer.pad_token_id) | |
probability_matrix.masked_fill_(padding_mask, value=0.0) | |
masked_indices = probability_matrix.bool() | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = torch.bernoulli(torch.full(labels.shape, 0.8)).bool() & masked_indices | |
inputs[indices_replaced] = self.tokenizer.convert_tokens_to_ids(self.tokenizer.mask_token) | |
# 10% of the time, we replace masked input tokens with random word | |
indices_random = torch.bernoulli(torch.full(labels.shape, 0.5)).bool() & masked_indices & ~indices_replaced | |
random_words = torch.randint(len(self.tokenizer), labels.shape, dtype=torch.long) | |
inputs[indices_random] = random_words[indices_random] | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels | |
def tf_mask_tokens(self, inputs: Any, mask_labels: Any) -> Tuple[Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. Set | |
'mask_labels' means we use whole word mask (wwm), we directly mask idxs according to it's ref. | |
""" | |
import tensorflow as tf | |
input_shape = tf.shape(inputs) | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for masked language modeling. Remove the" | |
" --mlm flag if you want to use this tokenizer." | |
) | |
labels = tf.identity(inputs) | |
# We sample a few tokens in each sequence for masked-LM training (with probability args.mlm_probability defaults to 0.15 in Bert/RoBERTa) | |
masked_indices = tf.cast(mask_labels, tf.bool) | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels | |
] | |
masked_indices = masked_indices & ~tf.cast(special_tokens_mask, dtype=tf.bool) | |
if self.tokenizer._pad_token is not None: | |
padding_mask = inputs == self.tokenizer.pad_token_id | |
masked_indices = masked_indices & ~padding_mask | |
# Replace unmasked indices with -100 in the labels since we only compute loss on masked tokens | |
labels = tf.where(masked_indices, inputs, -100) | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = self.tf_bernoulli(input_shape, 0.8) & masked_indices | |
inputs = tf.where(indices_replaced, self.tokenizer.mask_token_id, inputs) | |
# 10% of the time, we replace masked input tokens with random word | |
indices_random = self.tf_bernoulli(input_shape, 0.5) & masked_indices & ~indices_replaced | |
random_words = tf.random.uniform(input_shape, maxval=len(self.tokenizer), dtype=tf.int64) | |
inputs = tf.where(indices_random, random_words, inputs) | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels | |
def numpy_mask_tokens(self, inputs: Any, mask_labels: Any) -> Tuple[Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. Set | |
'mask_labels' means we use whole word mask (wwm), we directly mask idxs according to it's ref. | |
""" | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for masked language modeling. Remove the" | |
" --mlm flag if you want to use this tokenizer." | |
) | |
labels = np.copy(inputs) | |
# We sample a few tokens in each sequence for masked-LM training (with probability args.mlm_probability defaults to 0.15 in Bert/RoBERTa) | |
masked_indices = mask_labels.astype(bool) | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist() | |
] | |
masked_indices[np.array(special_tokens_mask, dtype=bool)] = 0 | |
if self.tokenizer._pad_token is not None: | |
padding_mask = labels == self.tokenizer.pad_token_id | |
masked_indices[padding_mask] = 0 | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = np.random.binomial(1, 0.8, size=labels.shape).astype(bool) & masked_indices | |
inputs[indices_replaced] = self.tokenizer.convert_tokens_to_ids(self.tokenizer.mask_token) | |
# 10% of the time, we replace masked input tokens with random word | |
# indices_random = torch.bernoulli(torch.full(labels.shape, 0.5)).bool() & masked_indices & ~indices_replaced | |
indices_random = ( | |
np.random.binomial(1, 0.5, size=labels.shape).astype(bool) & masked_indices & ~indices_replaced | |
) | |
random_words = np.random.randint(low=0, high=len(self.tokenizer), size=labels.shape, dtype=np.int64) | |
inputs[indices_random] = random_words[indices_random] | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels | |
class DataCollatorForSOP(DataCollatorForLanguageModeling): | |
""" | |
Data collator used for sentence order prediction task. | |
- collates batches of tensors, honoring their tokenizer's pad_token | |
- preprocesses batches for both masked language modeling and sentence order prediction | |
""" | |
def __init__(self, *args, **kwargs): | |
warnings.warn( | |
"DataCollatorForSOP is deprecated and will be removed in a future version, you can now use " | |
"DataCollatorForLanguageModeling instead.", | |
FutureWarning, | |
) | |
def __call__(self, examples: List[Dict[str, Any]]) -> Dict[str, Any]: | |
import torch | |
from torch.nn.utils.rnn import pad_sequence | |
input_ids = [example["input_ids"] for example in examples] | |
input_ids = _torch_collate_batch(input_ids, self.tokenizer) | |
input_ids, labels, attention_mask = self.mask_tokens(input_ids) | |
token_type_ids = [example["token_type_ids"] for example in examples] | |
# size of segment_ids varied because randomness, padding zero to the end as the original implementation | |
token_type_ids = pad_sequence(token_type_ids, batch_first=True, padding_value=self.tokenizer.pad_token_id) | |
sop_label_list = [example["sentence_order_label"] for example in examples] | |
sentence_order_label = torch.stack(sop_label_list) | |
return { | |
"input_ids": input_ids, | |
"labels": labels, | |
"attention_mask": attention_mask, | |
"token_type_ids": token_type_ids, | |
"sentence_order_label": sentence_order_label, | |
} | |
def mask_tokens(self, inputs: Any) -> Tuple[Any, Any, Any]: | |
""" | |
Prepare masked tokens inputs/labels/attention_mask for masked language modeling: 80% MASK, 10% random, 10% | |
original. N-gram not applied yet. | |
""" | |
import torch | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for masked language modeling. Remove the" | |
" --mlm flag if you want to use this tokenizer." | |
) | |
labels = inputs.clone() | |
# We sample a few tokens in each sequence for masked-LM training (with probability args.mlm_probability defaults to 0.15 in Bert/RoBERTa) | |
probability_matrix = torch.full(labels.shape, self.mlm_probability) | |
special_tokens_mask = [ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist() | |
] | |
probability_matrix.masked_fill_(torch.tensor(special_tokens_mask, dtype=torch.bool), value=0.0) | |
if self.tokenizer._pad_token is not None: | |
padding_mask = labels.eq(self.tokenizer.pad_token_id) | |
probability_matrix.masked_fill_(padding_mask, value=0.0) | |
masked_indices = torch.bernoulli(probability_matrix).bool() | |
# probability be `1` (masked), however in albert model attention mask `0` means masked, revert the value | |
attention_mask = (~masked_indices).float() | |
if self.tokenizer._pad_token is not None: | |
attention_padding_mask = labels.eq(self.tokenizer.pad_token_id) | |
attention_mask.masked_fill_(attention_padding_mask, value=1.0) | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens, -100 is default for CE compute | |
# 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK]) | |
indices_replaced = torch.bernoulli(torch.full(labels.shape, 0.8)).bool() & masked_indices | |
inputs[indices_replaced] = self.tokenizer.convert_tokens_to_ids(self.tokenizer.mask_token) | |
# 10% of the time, we replace masked input tokens with random word | |
indices_random = torch.bernoulli(torch.full(labels.shape, 0.5)).bool() & masked_indices & ~indices_replaced | |
random_words = torch.randint(len(self.tokenizer), labels.shape, dtype=torch.long) | |
inputs[indices_random] = random_words[indices_random] | |
# The rest of the time (10% of the time) we keep the masked input tokens unchanged | |
return inputs, labels, attention_mask | |
class DataCollatorForPermutationLanguageModeling(DataCollatorMixin): | |
""" | |
Data collator used for permutation language modeling. | |
- collates batches of tensors, honoring their tokenizer's pad_token | |
- preprocesses batches for permutation language modeling with procedures specific to XLNet | |
""" | |
tokenizer: PreTrainedTokenizerBase | |
plm_probability: float = 1 / 6 | |
max_span_length: int = 5 # maximum length of a span of masked tokens | |
return_tensors: str = "pt" | |
def torch_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
if isinstance(examples[0], Mapping): | |
examples = [e["input_ids"] for e in examples] | |
batch = _torch_collate_batch(examples, self.tokenizer) | |
inputs, perm_mask, target_mapping, labels = self.torch_mask_tokens(batch) | |
return {"input_ids": inputs, "perm_mask": perm_mask, "target_mapping": target_mapping, "labels": labels} | |
def tf_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
if isinstance(examples[0], Mapping): | |
examples = [e["input_ids"] for e in examples] | |
batch = _tf_collate_batch(examples, self.tokenizer) | |
inputs, perm_mask, target_mapping, labels = self.tf_mask_tokens(batch) | |
return {"input_ids": inputs, "perm_mask": perm_mask, "target_mapping": target_mapping, "labels": labels} | |
def numpy_call(self, examples: List[Union[List[int], Any, Dict[str, Any]]]) -> Dict[str, Any]: | |
if isinstance(examples[0], Mapping): | |
examples = [e["input_ids"] for e in examples] | |
batch = _numpy_collate_batch(examples, self.tokenizer) | |
inputs, perm_mask, target_mapping, labels = self.numpy_mask_tokens(batch) | |
return {"input_ids": inputs, "perm_mask": perm_mask, "target_mapping": target_mapping, "labels": labels} | |
def torch_mask_tokens(self, inputs: Any) -> Tuple[Any, Any, Any, Any]: | |
""" | |
The masked tokens to be predicted for a particular sequence are determined by the following algorithm: | |
0. Start from the beginning of the sequence by setting `cur_len = 0` (number of tokens processed so far). | |
1. Sample a `span_length` from the interval `[1, max_span_length]` (length of span of tokens to be masked) | |
2. Reserve a context of length `context_length = span_length / plm_probability` to surround span to be | |
masked | |
3. Sample a starting point `start_index` from the interval `[cur_len, cur_len + context_length - | |
span_length]` and mask tokens `start_index:start_index + span_length` | |
4. Set `cur_len = cur_len + context_length`. If `cur_len < max_len` (i.e. there are tokens remaining in the | |
sequence to be processed), repeat from Step 1. | |
""" | |
import torch | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for permutation language modeling." | |
" Please add a mask token if you want to use this tokenizer." | |
) | |
if inputs.size(1) % 2 != 0: | |
raise ValueError( | |
"This collator requires that sequence lengths be even to create a leakage-free perm_mask. Please see" | |
" relevant comments in source code for details." | |
) | |
labels = inputs.clone() | |
# Creating the mask and target_mapping tensors | |
masked_indices = torch.full(labels.shape, 0, dtype=torch.bool) | |
target_mapping = torch.zeros((labels.size(0), labels.size(1), labels.size(1)), dtype=torch.float32) | |
for i in range(labels.size(0)): | |
# Start from the beginning of the sequence by setting `cur_len = 0` (number of tokens processed so far). | |
cur_len = 0 | |
max_len = labels.size(1) | |
while cur_len < max_len: | |
# Sample a `span_length` from the interval `[1, max_span_length]` (length of span of tokens to be masked) | |
span_length = torch.randint(1, self.max_span_length + 1, (1,)).item() | |
# Reserve a context of length `context_length = span_length / plm_probability` to surround the span to be masked | |
context_length = int(span_length / self.plm_probability) | |
# Sample a starting point `start_index` from the interval `[cur_len, cur_len + context_length - span_length]` and mask tokens `start_index:start_index + span_length` | |
start_index = cur_len + torch.randint(context_length - span_length + 1, (1,)).item() | |
masked_indices[i, start_index : start_index + span_length] = 1 | |
# Set `cur_len = cur_len + context_length` | |
cur_len += context_length | |
# Since we're replacing non-masked tokens with -100 in the labels tensor instead of skipping them altogether, | |
# the i-th predict corresponds to the i-th token. | |
target_mapping[i] = torch.eye(labels.size(1)) | |
special_tokens_mask = torch.tensor( | |
[self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist()], | |
dtype=torch.bool, | |
) | |
masked_indices.masked_fill_(special_tokens_mask, value=0.0) | |
if self.tokenizer._pad_token is not None: | |
padding_mask = labels.eq(self.tokenizer.pad_token_id) | |
masked_indices.masked_fill_(padding_mask, value=0.0) | |
# Mask indicating non-functional tokens, where functional tokens are [SEP], [CLS], padding, etc. | |
non_func_mask = ~(padding_mask | special_tokens_mask) | |
inputs[masked_indices] = self.tokenizer.mask_token_id | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens | |
perm_mask = torch.zeros((labels.size(0), labels.size(1), labels.size(1)), dtype=torch.float32) | |
for i in range(labels.size(0)): | |
# Generate permutation indices i.e. sample a random factorisation order for the sequence. This will | |
# determine which tokens a given token can attend to (encoded in `perm_mask`). | |
# Note: Length of token sequence being permuted has to be less than or equal to reused sequence length | |
# (see documentation for `mems`), otherwise information may leak through due to reuse. In this implementation, | |
# we assume that reused length is half of sequence length and permutation length is equal to reused length. | |
# This requires that the sequence length be even. | |
# Create a linear factorisation order | |
perm_index = torch.arange(labels.size(1)) | |
# Split this into two halves, assuming that half the sequence is reused each time | |
perm_index = perm_index.reshape((-1, labels.size(1) // 2)).transpose(0, 1) | |
# Permute the two halves such that they do not cross over | |
perm_index = perm_index[torch.randperm(labels.size(1) // 2)] | |
# Flatten this out into the desired permuted factorisation order | |
perm_index = torch.flatten(perm_index.transpose(0, 1)) | |
# Set the permutation indices of non-masked (non-functional) tokens to the | |
# smallest index (-1) so that: | |
# (1) They can be seen by all other positions | |
# (2) They cannot see masked positions, so there won't be information leak | |
perm_index.masked_fill_(~masked_indices[i] & non_func_mask[i], -1) | |
# The logic for whether the i-th token can attend on the j-th token based on the factorisation order: | |
# 0 (can attend): If perm_index[i] > perm_index[j] or j is neither masked nor a functional token | |
# 1 (cannot attend): If perm_index[i] <= perm_index[j] and j is either masked or a functional token | |
perm_mask[i] = ( | |
perm_index.reshape((labels.size(1), 1)) <= perm_index.reshape((1, labels.size(1))) | |
) & masked_indices[i] | |
return inputs.long(), perm_mask, target_mapping, labels.long() | |
def tf_mask_tokens(self, inputs: Any) -> Tuple[Any, Any, Any, Any]: | |
""" | |
The masked tokens to be predicted for a particular sequence are determined by the following algorithm: | |
0. Start from the beginning of the sequence by setting `cur_len = 0` (number of tokens processed so far). | |
1. Sample a `span_length` from the interval `[1, max_span_length]` (length of span of tokens to be masked) | |
2. Reserve a context of length `context_length = span_length / plm_probability` to surround span to be | |
masked | |
3. Sample a starting point `start_index` from the interval `[cur_len, cur_len + context_length - | |
span_length]` and mask tokens `start_index:start_index + span_length` | |
4. Set `cur_len = cur_len + context_length`. If `cur_len < max_len` (i.e. there are tokens remaining in the | |
sequence to be processed), repeat from Step 1. | |
""" | |
import tensorflow as tf | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for permutation language modeling." | |
" Please add a mask token if you want to use this tokenizer." | |
) | |
if tf.shape(inputs)[1] % 2 != 0: | |
raise ValueError( | |
"This collator requires that sequence lengths be even to create a leakage-free perm_mask. Please see" | |
" relevant comments in source code for details." | |
) | |
labels = tf.identity(inputs) | |
# Creating the mask and target_mapping tensors | |
masked_indices = np.full(labels.shape.as_list(), 0, dtype=bool) | |
labels_shape = tf.shape(labels) | |
target_mapping = np.zeros((labels_shape[0], labels_shape[1], labels_shape[1]), dtype=np.float32) | |
for i in range(len(labels)): | |
# Start from the beginning of the sequence by setting `cur_len = 0` (number of tokens processed so far). | |
cur_len = 0 | |
max_len = tf.shape(labels)[1] | |
while cur_len < max_len: | |
# Sample a `span_length` from the interval `[1, max_span_length]` (length of span of tokens to be masked) | |
span_length = randint(1, self.max_span_length + 1) | |
# Reserve a context of length `context_length = span_length / plm_probability` to surround the span to be masked | |
context_length = int(span_length / self.plm_probability) | |
# Sample a starting point `start_index` from the interval `[cur_len, cur_len + context_length - span_length]` and mask tokens `start_index:start_index + span_length` | |
start_index = cur_len + randint(0, context_length - span_length + 1) | |
masked_indices[i, start_index : start_index + span_length] = 1 | |
# Set `cur_len = cur_len + context_length` | |
cur_len += context_length | |
# Since we're replacing non-masked tokens with -100 in the labels tensor instead of skipping them altogether, | |
# the i-th predict corresponds to the i-th token. | |
target_mapping[i] = np.eye(labels_shape[1]) | |
masked_indices = tf.cast(tf.convert_to_tensor(masked_indices), dtype=tf.bool) | |
target_mapping = tf.convert_to_tensor(target_mapping) | |
special_tokens_mask = tf.convert_to_tensor( | |
[ | |
self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) | |
for val in labels.numpy().tolist() | |
], | |
) | |
special_tokens_mask = tf.cast(special_tokens_mask, dtype=tf.bool) | |
masked_indices = masked_indices & ~special_tokens_mask | |
if self.tokenizer._pad_token is not None: | |
padding_mask = labels == self.tokenizer.pad_token_id | |
masked_indices = masked_indices & ~padding_mask | |
# Mask indicating non-functional tokens, where functional tokens are [SEP], [CLS], padding, etc. | |
non_func_mask = ~(padding_mask | special_tokens_mask) | |
inputs = tf.where(masked_indices, self.tokenizer.mask_token_id, inputs) | |
labels = tf.where(masked_indices, labels, -100) # We only compute loss on masked tokens | |
perm_mask = [] | |
for i in range(len(labels)): | |
# Generate permutation indices i.e. sample a random factorisation order for the sequence. This will | |
# determine which tokens a given token can attend to (encoded in `perm_mask`). | |
# Note: Length of token sequence being permuted has to be less than or equal to reused sequence length | |
# (see documentation for `mems`), otherwise information may leak through due to reuse. In this implementation, | |
# we assume that reused length is half of sequence length and permutation length is equal to reused length. | |
# This requires that the sequence length be even. | |
# Create a linear factorisation order | |
# tf.range is the equivalent of torch.arange | |
perm_index = tf.range(labels_shape[1]) | |
# Split this into two halves, assuming that half the sequence is reused each time | |
perm_index = tf.transpose(tf.reshape(perm_index, (-1, labels_shape[1] // 2))) | |
# Permute the two halves such that they do not cross over | |
perm_index = tf.random.shuffle(perm_index) # Shuffles along the first dimension | |
# Flatten this out into the desired permuted factorisation order | |
perm_index = tf.reshape(tf.transpose(perm_index), (-1,)) | |
# Set the permutation indices of non-masked (non-functional) tokens to the | |
# smallest index (-1) so that: | |
# (1) They can be seen by all other positions | |
# (2) They cannot see masked positions, so there won't be information leak | |
perm_index = tf.where(~masked_indices[i] & non_func_mask[i], -1, perm_index) | |
# The logic for whether the i-th token can attend on the j-th token based on the factorisation order: | |
# 0 (can attend): If perm_index[i] > perm_index[j] or j is neither masked nor a functional token | |
# 1 (cannot attend): If perm_index[i] <= perm_index[j] and j is either masked or a functional token | |
perm_mask.append( | |
(tf.reshape(perm_index, (labels_shape[1], 1)) <= tf.reshape(perm_index, (1, labels_shape[1]))) | |
& masked_indices[i] | |
) | |
perm_mask = tf.stack(perm_mask, axis=0) | |
return tf.cast(inputs, tf.int64), tf.cast(perm_mask, tf.float32), target_mapping, tf.cast(labels, tf.int64) | |
def numpy_mask_tokens(self, inputs: Any) -> Tuple[Any, Any, Any, Any]: | |
""" | |
The masked tokens to be predicted for a particular sequence are determined by the following algorithm: | |
0. Start from the beginning of the sequence by setting `cur_len = 0` (number of tokens processed so far). | |
1. Sample a `span_length` from the interval `[1, max_span_length]` (length of span of tokens to be masked) | |
2. Reserve a context of length `context_length = span_length / plm_probability` to surround span to be | |
masked | |
3. Sample a starting point `start_index` from the interval `[cur_len, cur_len + context_length - | |
span_length]` and mask tokens `start_index:start_index + span_length` | |
4. Set `cur_len = cur_len + context_length`. If `cur_len < max_len` (i.e. there are tokens remaining in the | |
sequence to be processed), repeat from Step 1. | |
""" | |
if self.tokenizer.mask_token is None: | |
raise ValueError( | |
"This tokenizer does not have a mask token which is necessary for permutation language modeling." | |
" Please add a mask token if you want to use this tokenizer." | |
) | |
if inputs.shape[1] % 2 != 0: | |
raise ValueError( | |
"This collator requires that sequence lengths be even to create a leakage-free perm_mask. Please see" | |
" relevant comments in source code for details." | |
) | |
labels = np.copy(inputs) | |
# Creating the mask and target_mapping tensors | |
masked_indices = np.full(labels.shape, 0, dtype=bool) | |
target_mapping = np.zeros((labels.shape[0], labels.shape[1], labels.shape[1]), dtype=np.float32) | |
for i in range(labels.shape[0]): | |
# Start from the beginning of the sequence by setting `cur_len = 0` (number of tokens processed so far). | |
cur_len = 0 | |
max_len = labels.shape[1] | |
while cur_len < max_len: | |
# Sample a `span_length` from the interval `[1, max_span_length]` (length of span of tokens to be masked) | |
span_length = randint(1, self.max_span_length + 1) | |
# Reserve a context of length `context_length = span_length / plm_probability` to surround the span to be masked | |
context_length = int(span_length / self.plm_probability) | |
# Sample a starting point `start_index` from the interval `[cur_len, cur_len + context_length - span_length]` and mask tokens `start_index:start_index + span_length` | |
start_index = cur_len + randint(0, context_length - span_length + 1) | |
masked_indices[i, start_index : start_index + span_length] = 1 | |
# Set `cur_len = cur_len + context_length` | |
cur_len += context_length | |
# Since we're replacing non-masked tokens with -100 in the labels tensor instead of skipping them altogether, | |
# the i-th predict corresponds to the i-th token. | |
target_mapping[i] = np.eye(labels.shape[1]) | |
special_tokens_mask = np.array( | |
[self.tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist()], | |
dtype=bool, | |
) | |
masked_indices[special_tokens_mask] = 0 | |
if self.tokenizer._pad_token is not None: | |
padding_mask = labels == self.tokenizer.pad_token_id | |
masked_indices[padding_mask] = 0.0 | |
# Mask indicating non-functional tokens, where functional tokens are [SEP], [CLS], padding, etc. | |
non_func_mask = ~(padding_mask | special_tokens_mask) | |
inputs[masked_indices] = self.tokenizer.mask_token_id | |
labels[~masked_indices] = -100 # We only compute loss on masked tokens | |
perm_mask = np.zeros((labels.shape[0], labels.shape[1], labels.shape[1]), dtype=np.float32) | |
for i in range(labels.shape[0]): | |
# Generate permutation indices i.e. sample a random factorisation order for the sequence. This will | |
# determine which tokens a given token can attend to (encoded in `perm_mask`). | |
# Note: Length of token sequence being permuted has to be less than or equal to reused sequence length | |
# (see documentation for `mems`), otherwise information may leak through due to reuse. In this implementation, | |
# we assume that reused length is half of sequence length and permutation length is equal to reused length. | |
# This requires that the sequence length be even. | |
# Create a linear factorisation order | |
perm_index = np.arange(labels.shape[1]) | |
# Split this into two halves, assuming that half the sequence is reused each time | |
perm_index = perm_index.reshape((-1, labels.shape[1] // 2)).T | |
# Permute the two halves such that they do not cross over | |
np.random.shuffle(perm_index) | |
# Flatten this out into the desired permuted factorisation order | |
perm_index = perm_index.T.flatten() | |
# Set the permutation indices of non-masked (non-functional) tokens to the | |
# smallest index (-1) so that: | |
# (1) They can be seen by all other positions | |
# (2) They cannot see masked positions, so there won't be information leak | |
perm_index[~masked_indices[i] & non_func_mask[i]] = -1 | |
# The logic for whether the i-th token can attend on the j-th token based on the factorisation order: | |
# 0 (can attend): If perm_index[i] > perm_index[j] or j is neither masked nor a functional token | |
# 1 (cannot attend): If perm_index[i] <= perm_index[j] and j is either masked or a functional token | |
perm_mask[i] = ( | |
perm_index.reshape((labels.shape[1], 1)) <= perm_index.reshape((1, labels.shape[1])) | |
) & masked_indices[i] | |
return inputs.astype(np.int64), perm_mask, target_mapping, labels.astype(np.int64) | |