m2-bert-80M-32k / bert_layers.py
Dan Fu
Automodel
0a2b9f1
# Copyright 2018 The Google AI Language Team Authors and The HuggingFace Inc. team.
# Copyright (c) 2018-2021, NVIDIA CORPORATION. All rights reserved.
# Copyright (c) 2022, Tri Dao.
# Copyright (c) 2023, MosaicML.
# Copyright (c) 2023, Dan Fu and Simran Arora.
import copy
import logging
import math
import os
import sys
import warnings
from typing import List, Optional, Tuple, Union
from functools import partial
# Add folder root to path to allow us to use relative imports regardless of what directory the script is run from
# sys.path.append(os.path.dirname(os.path.realpath(__file__)))
from .bert_padding import (index_first_axis,
index_put_first_axis, pad_input,
unpad_input, unpad_input_only)
import torch
import torch.nn as nn
from einops import rearrange
from torch.nn.modules.utils import consume_prefix_in_state_dict_if_present
from transformers.activations import ACT2FN
from transformers.modeling_outputs import (MaskedLMOutput,
SequenceClassifierOutput)
from transformers.models.bert.modeling_bert import BertPreTrainedModel
from .blockdiag_linear import BlockdiagLinear
from .monarch_mixer_sequence_mixer import MonarchMixerSequenceMixing
logger = logging.getLogger(__name__)
torch.backends.cuda.matmul.allow_tf32 = True
torch.backends.cudnn.allow_tf32 = True
class BertEmbeddings(nn.Module):
"""Construct the embeddings for words, ignoring position.
There are no positional embeddings since we use ALiBi and token_type
embeddings.
This module is modeled after the Hugging Face BERT's
:class:`~transformers.model.bert.modeling_bert.BertEmbeddings`, but is
modified as part of Mosaic BERT's ALiBi implementation. The key change is
that position embeddings are removed. Position information instead comes
from attention biases that scale linearly with the position distance
between query and key tokens.
This module ignores the `position_ids` input to the `forward` method.
"""
def __init__(self, config):
super().__init__()
self.word_embeddings = nn.Embedding(config.vocab_size,
config.hidden_size,
padding_idx=config.pad_token_id)
# ALiBi doesn't use position embeddings
if config.use_positional_encodings:
self.position_embeddings = nn.Embedding(config.max_position_embeddings, config.hidden_size)
self.use_positional_encodings = config.use_positional_encodings
self.token_type_embeddings = nn.Embedding(config.type_vocab_size,
config.hidden_size)
# self.LayerNorm is not snake-cased to stick with TensorFlow model
# variable name and be able to load any TensorFlow checkpoint file
self.LayerNorm = nn.LayerNorm(config.hidden_size,
eps=config.layer_norm_eps)
self.dropout = nn.Dropout(config.hidden_dropout_prob)
if config.use_positional_encodings:
self.register_buffer("position_ids", torch.arange(config.max_position_embeddings).expand((1, -1)))
self.register_buffer('token_type_ids',
torch.zeros(config.max_position_embeddings,
dtype=torch.long),
persistent=False)
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
token_type_ids: Optional[torch.LongTensor] = None,
position_ids: Optional[torch.LongTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
past_key_values_length: int = 0,
return_position_encodings: bool = False,
) -> torch.Tensor:
if (input_ids is not None) == (inputs_embeds is not None):
raise ValueError('Must specify either input_ids or input_embeds!')
if input_ids is not None:
input_shape = input_ids.size()
else:
assert inputs_embeds is not None # just for type checking
input_shape = inputs_embeds.size()[:-1]
seq_length = input_shape[1]
if position_ids is None:
if self.use_positional_encodings:
position_ids = self.position_ids[:, past_key_values_length : seq_length + past_key_values_length]
# Setting the token_type_ids to the registered buffer in constructor
# where it is all zeros, which usually occurs when it's auto-generated;
# registered buffer helps users when tracing the model without passing
# token_type_ids, solves issue #5664
if token_type_ids is None:
if hasattr(self, 'token_type_ids'):
assert isinstance(self.token_type_ids, torch.LongTensor)
buffered_token_type_ids = self.token_type_ids[:, :seq_length]
buffered_token_type_ids_expanded = buffered_token_type_ids.expand(
input_shape[0], seq_length)
token_type_ids = buffered_token_type_ids_expanded # type: ignore
else:
token_type_ids = torch.zeros(input_shape, # type: ignore
dtype=torch.long,
device=self.word_embeddings.device) # type: ignore # yapf: disable
if inputs_embeds is None:
inputs_embeds = self.word_embeddings(input_ids)
token_type_embeddings = self.token_type_embeddings(token_type_ids)
embeddings = inputs_embeds + token_type_embeddings
if self.use_positional_encodings:
position_embeddings = self.position_embeddings(position_ids)
embeddings += position_embeddings
embeddings = self.LayerNorm(embeddings)
embeddings = self.dropout(embeddings)
if return_position_encodings:
return embeddings, position_embeddings
else:
return embeddings
class BertMLP(nn.Module):
"""Applies the FFN at the end of each BERT layer."""
def __init__(self, config):
super().__init__()
self.config = config
if self.config.use_monarch_mlp:
linear_cls = partial(BlockdiagLinear, nblocks=self.config.monarch_mlp_nblocks)
else:
linear_cls = nn.Linear
self.gated_layers = linear_cls(config.hidden_size,
config.intermediate_size,
bias=False)
self.act = nn.GELU(approximate='none')
self.wo = linear_cls(config.intermediate_size, config.hidden_size)
self.layernorm = nn.LayerNorm(config.hidden_size,
eps=config.layer_norm_eps)
self.dropout = nn.Dropout(config.hidden_dropout_prob)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
"""Compute new hidden states from current hidden states.
Args:
hidden_states (torch.Tensor): The (unpadded) hidden states from
the attention layer [nnz, dim].
"""
residual_connection = hidden_states
hidden_states = self.gated_layers(hidden_states)
hidden_states = self.act(hidden_states)
hidden_states = self.dropout(hidden_states)
hidden_states = self.wo(hidden_states)
hidden_states = self.layernorm(hidden_states + residual_connection)
return hidden_states
class BertGatedLinearUnitMLP(nn.Module):
"""Applies the FFN at the end of each BERT layer with a Gated Linear Unit"""
def __init__(self, config):
super().__init__()
self.config = config
self.is_padded = True
if self.config.use_monarch_mlp:
linear_cls = partial(BlockdiagLinear, nblocks=self.config.monarch_mlp_nblocks)
else:
linear_cls = nn.Linear
self.gated_layers = linear_cls(
config.hidden_size,
config.intermediate_size * 2,
bias=False
)
self.act = nn.GELU(approximate='none')
self.wo = linear_cls(config.intermediate_size, config.hidden_size)
self.dropout = nn.Dropout(config.hidden_dropout_prob)
self.layernorm = nn.LayerNorm(config.hidden_size,
eps=config.layer_norm_eps)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
"""Compute new hidden states from current hidden states.
Args:
hidden_states (torch.Tensor): The (unpadded) hidden states from
the attention layer [nnz, dim].
"""
residual_connection = hidden_states
# compute the activation
hidden_states = self.gated_layers(hidden_states)
if self.is_padded:
gated = hidden_states[:, :, :self.config.intermediate_size]
non_gated = hidden_states[:, :, self.config.intermediate_size:]
else:
gated = hidden_states[:, :self.config.intermediate_size]
non_gated = hidden_states[:, self.config.intermediate_size:]
hidden_states = self.act(gated) * non_gated
hidden_states = self.dropout(hidden_states)
# multiply by the second matrix
hidden_states = self.wo(hidden_states)
# add the residual connection and post-LN
hidden_states = self.layernorm(hidden_states + residual_connection)
return hidden_states
class BertLayer(nn.Module):
"""BERT layer, which includes Sequence Mixing (e.g. Hyena) and State Mixing (e.g. MLP)."""
def __init__(self, config):
super(BertLayer, self).__init__()
mm_cls = MonarchMixerSequenceMixing
self.attention = mm_cls(
config.hidden_size,
l_max=config.long_conv_l_max,
hyena_kernel_lr=config.long_conv_kernel_learning_rate,
bidirectional=config.bidirectional,
hyena_lr_pos_emb=config.hyena_lr_pos_emb,
hyena_w=config.hyena_w,
hyena_w_mod=config.hyena_w_mod,
hyena_wd=config.hyena_wd,
hyena_emb_dim=config.hyena_emb_dim,
hyena_filter_dropout=config.hyena_filter_dropout,
hyena_filter_order=config.hyena_filter_order,
residual_long_conv=config.residual_long_conv,
hyena_training_additions=config.hyena_training_additions,
)
if config.use_glu_mlp:
self.mlp = BertGatedLinearUnitMLP(config)
else:
self.mlp = BertMLP(config)
def forward(
self,
hidden_states: torch.Tensor,
cu_seqlens: torch.Tensor,
seqlen: int,
subset_idx: Optional[torch.Tensor] = None,
indices: Optional[torch.Tensor] = None,
attn_mask: Optional[torch.Tensor] = None,
bias: Optional[torch.Tensor] = None,
) -> torch.Tensor:
"""Forward pass for a BERT layer, including both attention and MLP.
Args:
hidden_states: (total_nnz, dim)
cu_seqlens: (batch + 1,)
seqlen: int
subset_idx: () set of indices whose values we care about at the end of the layer
(e.g., the masked tokens, if this is the final layer).
indices: None or (total_nnz,)
attn_mask: None or (batch, max_seqlen_in_batch)
bias: None or (batch, heads, max_seqlen_in_batch, max_seqlen_in_batch)
"""
attention_output = self.attention(hidden_states)
if type(attention_output) == tuple:
attention_output, _ = attention_output
layer_output = self.mlp(attention_output)
return layer_output
class BertEncoder(nn.Module):
"""A stack of BERT layers providing the backbone of BERT.
Compared to the analogous Hugging Face BERT module, this module handles unpadding to reduce unnecessary computation
at padded tokens, and pre-computes attention biases to implement ALiBi.
"""
def __init__(self, config):
super().__init__()
layer = BertLayer(config)
self.layer = nn.ModuleList(
[copy.deepcopy(layer) for _ in range(config.num_hidden_layers)])
self.num_attention_heads = config.num_attention_heads
def rebuild_alibi_tensor(self,
size: int,
device: Optional[Union[torch.device, str]] = None):
# Alibi
# Following https://github.com/ofirpress/attention_with_linear_biases/issues/5 (Implementation 1)
# In the causal case, you can exploit the fact that softmax is invariant to a uniform translation
# of the logits, which makes the math work out *after* applying causal masking. If no causal masking
# will be applied, it is necessary to construct the diagonal mask.
n_heads = self.num_attention_heads
def _get_alibi_head_slopes(n_heads: int) -> List[float]:
def get_slopes_power_of_2(n_heads: int) -> List[float]:
start = (2**(-2**-(math.log2(n_heads) - 3)))
ratio = start
return [start * ratio**i for i in range(n_heads)]
# In the paper, they only train models that have 2^a heads for some a. This function
# has some good properties that only occur when the input is a power of 2. To
# maintain that even when the number of heads is not a power of 2, we use a
# workaround.
if math.log2(n_heads).is_integer():
return get_slopes_power_of_2(n_heads)
closest_power_of_2 = 2**math.floor(math.log2(n_heads))
slopes_a = get_slopes_power_of_2(closest_power_of_2)
slopes_b = _get_alibi_head_slopes(2 * closest_power_of_2)
slopes_b = slopes_b[0::2][:n_heads - closest_power_of_2]
return slopes_a + slopes_b
context_position = torch.arange(size, device=device)[:, None]
memory_position = torch.arange(size, device=device)[None, :]
relative_position = torch.abs(memory_position - context_position)
# [n_heads, max_token_length, max_token_length]
relative_position = relative_position.unsqueeze(0).expand(
n_heads, -1, -1)
slopes = torch.Tensor(_get_alibi_head_slopes(n_heads)).to(device)
alibi = slopes.unsqueeze(1).unsqueeze(1) * -relative_position
# [1, n_heads, max_token_length, max_token_length]
alibi = alibi.unsqueeze(0)
assert alibi.shape == torch.Size([1, n_heads, size, size])
self._current_alibi_size = size
self.alibi = alibi
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: torch.Tensor,
output_all_encoded_layers: Optional[bool] = True,
subset_mask: Optional[torch.Tensor] = None,
position_encodings: Optional[torch.Tensor] = None,
) -> List[torch.Tensor]:
extended_attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)
extended_attention_mask = extended_attention_mask.to(
dtype=next(self.parameters()).dtype) # fp16 compatibility
extended_attention_mask = (1.0 - extended_attention_mask) * -10000.0
attention_mask_bool = attention_mask.bool()
batch, seqlen = hidden_states.shape[:2]
cu_seqlens = None
indices = None
alibi_attn_mask = None
all_encoder_layers = []
for layer_module in self.layer:
hidden_states = layer_module(hidden_states,
cu_seqlens,
seqlen,
None,
indices,
attn_mask=attention_mask,
bias=alibi_attn_mask
)
if position_encodings is not None:
hidden_states = hidden_states + position_encodings
if output_all_encoded_layers:
all_encoder_layers.append(hidden_states)
if subset_mask is not None:
hidden_states = hidden_states[subset_mask]
if not output_all_encoded_layers:
all_encoder_layers.append(hidden_states)
return all_encoder_layers
class BertPooler(nn.Module):
def __init__(self, config):
super(BertPooler, self).__init__()
self.dense = nn.Linear(config.hidden_size, config.hidden_size)
self.activation = nn.Tanh()
self.pool_all = config.pool_all
def forward(self,
hidden_states: torch.Tensor,
pool: Optional[bool] = True,
mask= None) -> torch.Tensor:
# We "pool" the model by simply taking the hidden state corresponding
# to the first token.
if not self.pool_all:
first_token_tensor = hidden_states[:, 0] if pool else hidden_states
pooled_output = self.dense(first_token_tensor)
pooled_output = self.activation(pooled_output)
else:
# mean pool everything that isn't masked out
denom = torch.sum(mask, dim=1, keepdim=True)
mean_tensor = torch.sum((hidden_states) * mask.unsqueeze(-1), dim = 1) / denom
pooled_output = self.dense(mean_tensor)
pooled_output = self.activation(pooled_output)
return pooled_output
class BertPredictionHeadTransform(nn.Module):
def __init__(self, config):
super().__init__()
self.dense = nn.Linear(config.hidden_size, config.hidden_size)
if isinstance(config.hidden_act, str):
self.transform_act_fn = ACT2FN[config.hidden_act]
else:
self.transform_act_fn = config.hidden_act
self.LayerNorm = torch.nn.LayerNorm(config.hidden_size, eps=1e-12)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
hidden_states = self.dense(hidden_states)
hidden_states = self.transform_act_fn(hidden_states)
hidden_states = self.LayerNorm(hidden_states)
return hidden_states
class BertModel(BertPreTrainedModel):
"""Overall BERT model.
Args:
config: a BertConfig class instance with the configuration to build a new model
Inputs:
`input_ids`: a torch.LongTensor of shape [batch_size, sequence_length]
with the word token indices in the vocabulary(see the tokens preprocessing logic in the scripts
`extract_features.py`, `run_classifier.py` and `run_squad.py`)
`token_type_ids`: an optional torch.LongTensor of shape [batch_size, sequence_length] with the token
types indices selected in [0, 1]. Type 0 corresponds to a `sentence A` and type 1 corresponds to
a `sentence B` token (see BERT paper for more details).
`attention_mask`: an optional torch.LongTensor of shape [batch_size, sequence_length] with indices
selected in [0, 1]. It's a mask to be used if the input sequence length is smaller than the max
input sequence length in the current batch. It's the mask that we typically use for attention when
a batch has varying length sentences.
`output_all_encoded_layers`: boolean which controls the content of the `encoded_layers` output as described below. Default: `True`.
Outputs: Tuple of (encoded_layers, pooled_output)
`encoded_layers`: controlled by `output_all_encoded_layers` argument:
- `output_all_encoded_layers=True`: outputs a list of the full sequences of encoded-hidden-states at the end
of each attention block (i.e. 12 full sequences for BERT-base, 24 for BERT-large), each
encoded-hidden-state is a torch.FloatTensor of size [batch_size, sequence_length, hidden_size],
- `output_all_encoded_layers=False`: outputs only the full sequence of hidden-states corresponding
to the last attention block of shape [batch_size, sequence_length, hidden_size],
`pooled_output`: a torch.FloatTensor of size [batch_size, hidden_size] which is the output of a
classifier pretrained on top of the hidden state associated to the first character of the
input (`CLS`) to train on the Next-Sentence task (see BERT's paper).
Example usage:
```python
# Already been converted into WordPiece token ids
input_ids = torch.LongTensor([[31, 51, 99], [15, 5, 0]])
input_mask = torch.LongTensor([[1, 1, 1], [1, 1, 0]])
token_type_ids = torch.LongTensor([[0, 0, 1], [0, 1, 0]])
config = modeling.BertConfig(vocab_size_or_config_json_file=32000, hidden_size=768,
num_hidden_layers=12, num_attention_heads=12, intermediate_size=3072)
model = BertModel(config=config)
all_encoder_layers, pooled_output = model(input_ids, token_type_ids, input_mask)
```
"""
def __init__(self, config, add_pooling_layer=True):
super(BertModel, self).__init__(config)
self.embeddings = BertEmbeddings(config)
self.encoder = BertEncoder(config)
self.pooler = BertPooler(config) if add_pooling_layer else None
self.post_init()
def get_input_embeddings(self):
return self.embeddings.word_embeddings
def set_input_embeddings(self, value):
self.embeddings.word_embeddings = value
def forward(
self,
input_ids: torch.Tensor,
token_type_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
output_all_encoded_layers: Optional[bool] = False,
masked_tokens_mask: Optional[torch.Tensor] = None,
**kwargs
) -> Tuple[Union[List[torch.Tensor], torch.Tensor], Optional[torch.Tensor]]:
if attention_mask is None:
attention_mask = torch.ones_like(input_ids)
if token_type_ids is None:
token_type_ids = torch.zeros_like(input_ids)
embedding_output = self.embeddings(
input_ids,
token_type_ids,
position_ids
)
position_encodings = None
subset_mask = []
first_col_mask = []
if masked_tokens_mask is None:
subset_mask = None
else:
first_col_mask = torch.zeros_like(masked_tokens_mask)
first_col_mask[:, 0] = True
subset_mask = masked_tokens_mask | first_col_mask
encoder_outputs = self.encoder(
embedding_output,
attention_mask,
output_all_encoded_layers=output_all_encoded_layers,
subset_mask=subset_mask,
position_encodings=position_encodings)
if masked_tokens_mask is None:
sequence_output = encoder_outputs[-1]
pooled_output = self.pooler(
sequence_output, mask = attention_mask) if self.pooler is not None else None
else:
# TD [2022-03-01]: the indexing here is very tricky.
attention_mask_bool = attention_mask.bool()
subset_idx = subset_mask[attention_mask_bool] # type: ignore
sequence_output = encoder_outputs[-1][
masked_tokens_mask[attention_mask_bool][subset_idx]]
if self.pooler is not None:
pool_input = encoder_outputs[-1][
first_col_mask[attention_mask_bool][subset_idx]]
pooled_output = self.pooler(pool_input, pool=False, mask = attention_mask)
else:
pooled_output = None
if not output_all_encoded_layers:
encoder_outputs = sequence_output
if self.pooler is not None:
return encoder_outputs, pooled_output
return encoder_outputs, None
###################
# Bert Heads
###################
class BertLMPredictionHead(nn.Module):
def __init__(self, config, bert_model_embedding_weights):
super().__init__()
self.transform = BertPredictionHeadTransform(config)
# The output weights are the same as the input embeddings, but there is
# an output-only bias for each token.
self.decoder = nn.Linear(bert_model_embedding_weights.size(1),
bert_model_embedding_weights.size(0))
self.decoder.weight = bert_model_embedding_weights
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
hidden_states = self.transform(hidden_states)
hidden_states = self.decoder(hidden_states)
return hidden_states
class BertOnlyMLMHead(nn.Module):
def __init__(self, config, bert_model_embedding_weights):
super().__init__()
self.predictions = BertLMPredictionHead(config,
bert_model_embedding_weights)
def forward(self, sequence_output: torch.Tensor) -> torch.Tensor:
prediction_scores = self.predictions(sequence_output)
return prediction_scores
class BertOnlyNSPHead(nn.Module):
def __init__(self, config):
super().__init__()
self.seq_relationship = nn.Linear(config.hidden_size, 2)
def forward(self, pooled_output: torch.Tensor) -> torch.Tensor:
seq_relationship_score = self.seq_relationship(pooled_output)
return seq_relationship_score
#######################
# Construct Bert model
#######################
class BertForMaskedLM(BertPreTrainedModel):
def __init__(self, config):
super().__init__(config)
if config.is_decoder:
warnings.warn(
'If you want to use `BertForMaskedLM` make sure `config.is_decoder=False` for '
'bi-directional self-attention.')
self.bert = BertModel(config, add_pooling_layer=False)
self.cls = BertOnlyMLMHead(config,
self.bert.embeddings.word_embeddings.weight)
# Initialize weights and apply final processing
self.post_init()
@classmethod
def from_composer(cls,
pretrained_checkpoint,
state_dict=None,
cache_dir=None,
from_tf=False,
config=None,
*inputs,
**kwargs):
"""Load from pre-trained."""
model = cls(config, *inputs, **kwargs)
if from_tf:
raise ValueError(
'TensorFlow is not supported.')
state_dict = torch.load(pretrained_checkpoint)
# If the state_dict was saved after wrapping with `composer.HuggingFaceModel`, it takes on the `model` prefix
consume_prefix_in_state_dict_if_present(state_dict, prefix='model.')
missing_keys, unexpected_keys = model.load_state_dict(state_dict,
strict=False)
if len(missing_keys) > 0:
logger.warning(
f"Found these missing keys in the checkpoint: {', '.join(missing_keys)}"
)
if len(unexpected_keys) > 0:
logger.warning(
f"Found these unexpected keys in the checkpoint: {', '.join(unexpected_keys)}"
)
return model
def get_output_embeddings(self):
return self.cls.predictions.decoder
def set_output_embeddings(self, new_embeddings):
self.cls.predictions.decoder = new_embeddings
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
token_type_ids: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
encoder_hidden_states: Optional[torch.Tensor] = None,
encoder_attention_mask: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple[torch.Tensor], MaskedLMOutput]:
# labels should be a `torch.LongTensor` of shape
# `(batch_size, sequence_length)`. These are used for computing the
# masked language modeling loss.
#
# Indices should be in `[-100, 0, ..., config.vocab_size]` (see
# `input_ids` docstring) Tokens with indices set to `-100` are ignored
# (masked), the loss is only computed for the tokens with labels in `[0,
# ..., config.vocab_size]`
#
# Prediction scores are only computed for masked tokens and the (bs,
# seqlen) dimensions are flattened
if (input_ids is not None) == (inputs_embeds is not None):
raise ValueError('Must specify either input_ids or input_embeds!')
if labels is None:
masked_tokens_mask = None
else:
masked_tokens_mask = labels > 0
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
outputs = self.bert(
input_ids,
attention_mask=attention_mask,
token_type_ids=token_type_ids,
position_ids=position_ids,
head_mask=head_mask,
inputs_embeds=inputs_embeds,
encoder_hidden_states=encoder_hidden_states,
encoder_attention_mask=encoder_attention_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
masked_tokens_mask=masked_tokens_mask,
)
if torch.isnan(outputs[0]).any():
print("NaNs in outputs.")
raise ValueError()
#print("MLM Outputs")
#print(outputs[0].shape)
pooled_output = outputs[0]
last_hidden_state_formatted = outputs[0][:,0,:].view(-1, self.config.hidden_size)
return {"sentence_embedding": last_hidden_state_formatted}
def prepare_inputs_for_generation(self, input_ids: torch.Tensor,
attention_mask: torch.Tensor,
**model_kwargs):
input_shape = input_ids.shape
effective_batch_size = input_shape[0]
# add a dummy token
if self.config.pad_token_id is None:
raise ValueError('The PAD token should be defined for generation')
attention_mask = torch.cat([
attention_mask,
attention_mask.new_zeros((attention_mask.shape[0], 1))
], dim=-1)
dummy_token = torch.full((effective_batch_size, 1),
self.config.pad_token_id,
dtype=torch.long,
device=input_ids.device)
input_ids = torch.cat([input_ids, dummy_token], dim=1)
return {'input_ids': input_ids, 'attention_mask': attention_mask}
class BertForSequenceClassification(BertPreTrainedModel):
"""Bert Model transformer with a sequence classification/regression head.
This head is just a linear layer on top of the pooled output. Used for,
e.g., GLUE tasks.
"""
def __init__(self, config):
super().__init__(config)
self.num_labels = config.num_labels
self.config = config
self.bert = BertModel(config)
classifier_dropout = (config.classifier_dropout
if config.classifier_dropout is not None else
config.hidden_dropout_prob)
self.dropout = nn.Dropout(classifier_dropout)
self.classifier = nn.Linear(config.hidden_size, config.num_labels)
# Initialize weights and apply final processing
self.post_init()
@classmethod
def from_composer(cls,
pretrained_checkpoint,
state_dict=None,
cache_dir=None,
from_tf=False,
config=None,
*inputs,
**kwargs):
"""Load from pre-trained."""
model = cls(config, *inputs, **kwargs)
if from_tf:
raise ValueError(
'TensorFlow is not supported.')
state_dict = torch.load(pretrained_checkpoint)
# If the state_dict was saved after wrapping with `composer.HuggingFaceModel`, it takes on the `model` prefix
consume_prefix_in_state_dict_if_present(state_dict, prefix='model.')
missing_keys, unexpected_keys = model.load_state_dict(state_dict,
strict=False)
if len(missing_keys) > 0:
logger.warning(
f"Found these missing keys in the checkpoint: {', '.join(missing_keys)}"
)
if len(unexpected_keys) > 0:
logger.warning(
f"Found these unexpected keys in the checkpoint: {', '.join(unexpected_keys)}"
)
return model
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
token_type_ids: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple[torch.Tensor], SequenceClassifierOutput]:
# labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
# Labels for computing the sequence classification/regression loss.
# Indices should be in `[0, ..., config.num_labels - 1]`.
# If `config.num_labels == 1` a regression loss is computed
# (mean-square loss). If `config.num_labels > 1` a classification loss
# is computed (cross-entropy).
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
outputs = self.bert(
input_ids,
attention_mask=attention_mask,
token_type_ids=token_type_ids,
position_ids=position_ids,
head_mask=head_mask,
inputs_embeds=inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
pooled_output = outputs[1]
pooled_output = self.dropout(pooled_output)
logits = self.classifier(pooled_output)
loss = None
if labels is not None:
# Compute loss
if self.config.problem_type is None:
if self.num_labels == 1:
self.config.problem_type = 'regression'
elif self.num_labels > 1 and (labels.dtype == torch.long or
labels.dtype == torch.int):
self.config.problem_type = 'single_label_classification'
else:
self.config.problem_type = 'multi_label_classification'
if self.config.problem_type == 'regression':
loss_fct = nn.MSELoss()
if self.num_labels == 1:
loss = loss_fct(logits.squeeze(), labels.squeeze())
else:
loss = loss_fct(logits, labels)
elif self.config.problem_type == 'single_label_classification':
loss_fct = nn.CrossEntropyLoss()
loss = loss_fct(logits.view(-1, self.num_labels),
labels.view(-1))
elif self.config.problem_type == 'multi_label_classification':
loss_fct = nn.BCEWithLogitsLoss()
loss = loss_fct(logits, labels)
if not return_dict:
output = (logits,) + outputs[2:]
return ((loss,) + output) if loss is not None else output
return SequenceClassifierOutput(
loss=loss,
logits=logits,
hidden_states=None,
attentions=None,
)
class BertForTextEncoding(BertPreTrainedModel):
def __init__(self, config):
super().__init__(config)
if config.is_decoder:
warnings.warn(
'If you want to use `BertForMaskedLM` make sure `config.is_decoder=False` for '
'bi-directional self-attention.')
self.bert = BertModel(config, add_pooling_layer=True)
# Initialize weights and apply final processing
self.post_init()
@classmethod
def from_composer(cls,
pretrained_checkpoint,
state_dict=None,
cache_dir=None,
from_tf=False,
config=None,
*inputs,
**kwargs):
"""Load from pre-trained."""
model = cls(config, *inputs, **kwargs)
if from_tf:
raise ValueError(
'TensorFlow is not supported.')
state_dict = torch.load(pretrained_checkpoint)
# If the state_dict was saved after wrapping with `composer.HuggingFaceModel`, it takes on the `model` prefix
consume_prefix_in_state_dict_if_present(state_dict, prefix='model.')
missing_keys, unexpected_keys = model.load_state_dict(state_dict,
strict=False)
if len(missing_keys) > 0:
logger.warning(
f"Found these missing keys in the checkpoint: {', '.join(missing_keys)}"
)
if len(unexpected_keys) > 0:
logger.warning(
f"Found these unexpected keys in the checkpoint: {', '.join(unexpected_keys)}"
)
return model
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
token_type_ids: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
head_mask: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
encoder_hidden_states: Optional[torch.Tensor] = None,
encoder_attention_mask: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple[torch.Tensor], MaskedLMOutput]:
if (input_ids is not None) == (inputs_embeds is not None):
raise ValueError('Must specify either input_ids or input_embeds!')
if labels is None:
masked_tokens_mask = None
else:
masked_tokens_mask = labels > 0
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
outputs = self.bert(
input_ids,
attention_mask=attention_mask,
token_type_ids=token_type_ids,
position_ids=position_ids,
head_mask=head_mask,
inputs_embeds=inputs_embeds,
encoder_hidden_states=encoder_hidden_states,
encoder_attention_mask=encoder_attention_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
masked_tokens_mask=masked_tokens_mask,
)
pooled_output = outputs[1]
return {"sentence_embedding": pooled_output}
def prepare_inputs_for_generation(self, input_ids: torch.Tensor,
attention_mask: torch.Tensor,
**model_kwargs):
input_shape = input_ids.shape
effective_batch_size = input_shape[0]
# add a dummy token
if self.config.pad_token_id is None:
raise ValueError('The PAD token should be defined for generation')
attention_mask = torch.cat([
attention_mask,
attention_mask.new_zeros((attention_mask.shape[0], 1))
], dim=-1)
dummy_token = torch.full((effective_batch_size, 1),
self.config.pad_token_id,
dtype=torch.long,
device=input_ids.device)
input_ids = torch.cat([input_ids, dummy_token], dim=1)
return {'input_ids': input_ids, 'attention_mask': attention_mask}