443f67e887
* fix resize tokens
* correct mobile_bert
* move embedding fix into modeling_utils.py
* refactor
* fix lm head resize
* refactor
* break lines to make sylvain happy
* add news tests
* fix typo
* improve test
* skip bart-like for now
* check if base_model = get(...) is necessary
* clean files
* improve test
* fix tests
* revert style templates
* Update templates/adding_a_new_model/cookiecutter-template-{{cookiecutter.modelname}}/modeling_{{cookiecutter.lowercase_modelname}}.py
691 lines
28 KiB
Python
691 lines
28 KiB
Python
# coding=utf-8
|
|
# Copyright 2018 Salesforce and HuggingFace Inc. team.
|
|
# Copyright (c) 2018, NVIDIA CORPORATION. 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.
|
|
""" PyTorch CTRL model."""
|
|
|
|
import numpy as np
|
|
import torch
|
|
import torch.nn as nn
|
|
from torch.nn import CrossEntropyLoss, MSELoss
|
|
|
|
from ...file_utils import add_code_sample_docstrings, add_start_docstrings, add_start_docstrings_to_model_forward
|
|
from ...modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast, SequenceClassifierOutput
|
|
from ...modeling_utils import Conv1D, PreTrainedModel, find_pruneable_heads_and_indices, prune_linear_layer
|
|
from ...utils import logging
|
|
from .configuration_ctrl import CTRLConfig
|
|
|
|
|
|
logger = logging.get_logger(__name__)
|
|
|
|
_CONFIG_FOR_DOC = "CTRLConfig"
|
|
_TOKENIZER_FOR_DOC = "CTRLTokenizer"
|
|
|
|
CTRL_PRETRAINED_MODEL_ARCHIVE_LIST = [
|
|
"ctrl"
|
|
# See all CTRL models at https://huggingface.co/models?filter=ctrl
|
|
]
|
|
|
|
|
|
def angle_defn(pos, i, d_model_size):
|
|
angle_rates = 1 / torch.pow(10000, (2 * (i // 2)) / d_model_size)
|
|
return pos * angle_rates
|
|
|
|
|
|
def positional_encoding(position, d_model_size, dtype):
|
|
# create the sinusoidal pattern for the positional encoding
|
|
angle_rads = angle_defn(
|
|
torch.arange(position, dtype=dtype).unsqueeze(1),
|
|
torch.arange(d_model_size, dtype=dtype).unsqueeze(0),
|
|
d_model_size,
|
|
)
|
|
|
|
sines = torch.sin(angle_rads[:, 0::2])
|
|
cosines = torch.cos(angle_rads[:, 1::2])
|
|
|
|
pos_encoding = torch.cat([sines, cosines], dim=-1)
|
|
return pos_encoding
|
|
|
|
|
|
def scaled_dot_product_attention(q, k, v, mask, attention_mask=None, head_mask=None):
|
|
# calculate attention
|
|
matmul_qk = torch.matmul(q, k.permute(0, 1, 3, 2))
|
|
|
|
dk = k.shape[-1]
|
|
scaled_attention_logits = matmul_qk / np.sqrt(dk)
|
|
|
|
if mask is not None:
|
|
nd, ns = scaled_attention_logits.size(-2), scaled_attention_logits.size(-1)
|
|
scaled_attention_logits += mask[ns - nd : ns, :ns] * -1e4
|
|
|
|
if attention_mask is not None:
|
|
# Apply the attention mask
|
|
scaled_attention_logits = scaled_attention_logits + attention_mask
|
|
|
|
attention_weights = torch.softmax(scaled_attention_logits, dim=-1)
|
|
|
|
# Mask heads if we want to
|
|
if head_mask is not None:
|
|
attention_weights = attention_weights * head_mask
|
|
|
|
output = torch.matmul(attention_weights, v)
|
|
|
|
return output, attention_weights
|
|
|
|
|
|
class MultiHeadAttention(torch.nn.Module):
|
|
def __init__(self, d_model_size, num_heads):
|
|
super().__init__()
|
|
self.num_heads = num_heads
|
|
self.d_model_size = d_model_size
|
|
|
|
self.depth = int(d_model_size / self.num_heads)
|
|
|
|
self.Wq = torch.nn.Linear(d_model_size, d_model_size)
|
|
self.Wk = torch.nn.Linear(d_model_size, d_model_size)
|
|
self.Wv = torch.nn.Linear(d_model_size, d_model_size)
|
|
|
|
self.dense = torch.nn.Linear(d_model_size, d_model_size)
|
|
self.pruned_heads = set()
|
|
|
|
def prune_heads(self, heads):
|
|
attention_head_size = self.d_model_size // self.num_heads
|
|
if len(heads) == 0:
|
|
return
|
|
heads, index = find_pruneable_heads_and_indices(heads, self.num_heads, attention_head_size, self.pruned_heads)
|
|
|
|
# Prune linear layers
|
|
self.Wq = prune_linear_layer(self.Wq, index)
|
|
self.Wk = prune_linear_layer(self.Wk, index)
|
|
self.Wv = prune_linear_layer(self.Wv, index)
|
|
self.dense = prune_linear_layer(self.dense, index, dim=1)
|
|
|
|
# Update hyper params
|
|
self.num_heads = self.num_heads - len(heads)
|
|
self.d_model_size = attention_head_size * self.num_heads
|
|
self.pruned_heads = self.pruned_heads.union(heads)
|
|
|
|
def split_into_heads(self, x, batch_size):
|
|
x = x.reshape(batch_size, -1, self.num_heads, self.depth)
|
|
return x.permute([0, 2, 1, 3])
|
|
|
|
def forward(
|
|
self,
|
|
v,
|
|
k,
|
|
q,
|
|
mask,
|
|
layer_past=None,
|
|
attention_mask=None,
|
|
head_mask=None,
|
|
use_cache=False,
|
|
output_attentions=False,
|
|
):
|
|
batch_size = q.shape[0]
|
|
|
|
q = self.Wq(q)
|
|
k = self.Wk(k)
|
|
v = self.Wv(v)
|
|
|
|
q = self.split_into_heads(q, batch_size)
|
|
k = self.split_into_heads(k, batch_size)
|
|
v = self.split_into_heads(v, batch_size)
|
|
if layer_past is not None:
|
|
past_key, past_value = layer_past[0], layer_past[1]
|
|
k = torch.cat((past_key, k), dim=-2)
|
|
v = torch.cat((past_value, v), dim=-2)
|
|
|
|
if use_cache is True:
|
|
present = torch.stack((k, v))
|
|
else:
|
|
present = (None,)
|
|
|
|
output = scaled_dot_product_attention(q, k, v, mask, attention_mask, head_mask)
|
|
scaled_attention = output[0].permute([0, 2, 1, 3])
|
|
attn = output[1]
|
|
original_size_attention = scaled_attention.reshape(batch_size, -1, self.d_model_size)
|
|
output = self.dense(original_size_attention)
|
|
|
|
outputs = (output, present)
|
|
if output_attentions:
|
|
outputs = outputs + (attn,)
|
|
return outputs
|
|
|
|
|
|
def point_wise_feed_forward_network(d_model_size, dff):
|
|
return torch.nn.Sequential(torch.nn.Linear(d_model_size, dff), torch.nn.ReLU(), torch.nn.Linear(dff, d_model_size))
|
|
|
|
|
|
class EncoderLayer(torch.nn.Module):
|
|
def __init__(self, d_model_size, num_heads, dff, rate=0.1):
|
|
super().__init__()
|
|
|
|
self.multi_head_attention = MultiHeadAttention(d_model_size, num_heads)
|
|
self.ffn = point_wise_feed_forward_network(d_model_size, dff)
|
|
|
|
self.layernorm1 = torch.nn.LayerNorm(d_model_size, eps=1e-6)
|
|
self.layernorm2 = torch.nn.LayerNorm(d_model_size, eps=1e-6)
|
|
|
|
self.dropout1 = torch.nn.Dropout(rate)
|
|
self.dropout2 = torch.nn.Dropout(rate)
|
|
|
|
def forward(
|
|
self, x, mask, layer_past=None, attention_mask=None, head_mask=None, use_cache=False, output_attentions=False
|
|
):
|
|
normed = self.layernorm1(x)
|
|
attn_outputs = self.multi_head_attention(
|
|
normed,
|
|
normed,
|
|
normed,
|
|
mask,
|
|
layer_past=layer_past,
|
|
attention_mask=attention_mask,
|
|
head_mask=head_mask,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
)
|
|
attn_output = attn_outputs[0]
|
|
attn_output = self.dropout1(attn_output)
|
|
out1 = x + attn_output
|
|
|
|
out2 = self.layernorm2(out1)
|
|
ffn_output = self.ffn(out2)
|
|
ffn_output = self.dropout2(ffn_output)
|
|
out2 = out1 + ffn_output
|
|
|
|
outputs = (out2,) + attn_outputs[1:]
|
|
return outputs
|
|
|
|
|
|
class CTRLPreTrainedModel(PreTrainedModel):
|
|
"""
|
|
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
|
|
models.
|
|
"""
|
|
|
|
config_class = CTRLConfig
|
|
base_model_prefix = "transformer"
|
|
|
|
def _init_weights(self, module):
|
|
"""Initialize the weights."""
|
|
if isinstance(module, (nn.Linear, nn.Embedding, Conv1D)):
|
|
# Slightly different from the TF version which uses truncated_normal for initialization
|
|
# cf https://github.com/pytorch/pytorch/pull/5617
|
|
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
|
|
if isinstance(module, (nn.Linear, Conv1D)) and module.bias is not None:
|
|
module.bias.data.zero_()
|
|
elif isinstance(module, nn.LayerNorm):
|
|
module.bias.data.zero_()
|
|
module.weight.data.fill_(1.0)
|
|
|
|
|
|
CTRL_START_DOCSTRING = r"""
|
|
|
|
This model inherits from :class:`~transformers.PreTrainedModel`. Check the superclass documentation for the generic
|
|
methods the library implements for all its model (such as downloading or saving, resizing the input embeddings,
|
|
pruning heads etc.)
|
|
|
|
This model is also a PyTorch `torch.nn.Module <https://pytorch.org/docs/stable/nn.html#torch.nn.Module>`__
|
|
subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to
|
|
general usage and behavior.
|
|
|
|
Parameters:
|
|
config (:class:`~transformers.CTRLConfig`): Model configuration class with all the parameters of the model.
|
|
Initializing with a config file does not load the weights associated with the model, only the
|
|
configuration. Check out the :meth:`~transformers.PreTrainedModel.from_pretrained` method to load the model
|
|
weights.
|
|
"""
|
|
|
|
CTRL_INPUTS_DOCSTRING = r"""
|
|
Args:
|
|
input_ids (:obj:`torch.LongTensor` of shape :obj:`(batch_size, sequence_length)`):
|
|
:obj:`input_ids_length` = ``sequence_length`` if :obj:`past_key_values` is ``None`` else
|
|
``past_key_values[0].shape[-2]`` (``sequence_length`` of input past key value states). Indices of input
|
|
sequence tokens in the vocabulary.
|
|
|
|
If :obj:`past_key_values` is used, only input IDs that do not have their past calculated should be passed
|
|
as ``input_ids``.
|
|
|
|
Indices can be obtained using :class:`~transformers.CTRLTokenizer`. See
|
|
:meth:`transformers.PreTrainedTokenizer.__call__` and :meth:`transformers.PreTrainedTokenizer.encode` for
|
|
details.
|
|
|
|
`What are input IDs? <../glossary.html#input-ids>`__
|
|
past_key_values (:obj:`List[torch.FloatTensor]` of length :obj:`config.n_layers`):
|
|
Contains pre-computed hidden-states (key and values in the attention blocks) as computed by the model (see
|
|
:obj:`past_key_values` output below). Can be used to speed up sequential decoding. The ``input_ids`` which
|
|
have their past given to this model should not be passed as input ids as they have already been computed.
|
|
attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Mask to avoid performing attention on padding token indices. Mask values selected in ``[0, 1]``:
|
|
|
|
- 1 for tokens that are **not masked**,
|
|
- 0 for tokens that are **masked**.
|
|
|
|
`What are attention masks? <../glossary.html#attention-mask>`__
|
|
token_type_ids (:obj:`torch.LongTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Segment token indices to indicate first and second portions of the inputs. Indices are selected in ``[0,
|
|
1]``:
|
|
|
|
- 0 corresponds to a `sentence A` token,
|
|
- 1 corresponds to a `sentence B` token.
|
|
|
|
`What are token type IDs? <../glossary.html#token-type-ids>`_
|
|
position_ids (:obj:`torch.LongTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Indices of positions of each input sequence tokens in the position embeddings. Selected in the range ``[0,
|
|
config.max_position_embeddings - 1]``.
|
|
|
|
`What are position IDs? <../glossary.html#position-ids>`_
|
|
head_mask (:obj:`torch.FloatTensor` of shape :obj:`(num_heads,)` or :obj:`(num_layers, num_heads)`, `optional`):
|
|
Mask to nullify selected heads of the self-attention modules. Mask values selected in ``[0, 1]``:
|
|
|
|
- 1 indicates the head is **not masked**,
|
|
- 0 indicates the head is **masked**.
|
|
|
|
inputs_embeds (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`, `optional`):
|
|
Optionally, instead of passing :obj:`input_ids` you can choose to directly pass an embedded representation.
|
|
This is useful if you want more control over how to convert :obj:`input_ids` indices into associated
|
|
vectors than the model's internal embedding lookup matrix.
|
|
use_cache (:obj:`bool`, `optional`):
|
|
If set to :obj:`True`, :obj:`past_key_values` key value states are returned and can be used to speed up
|
|
decoding (see :obj:`past_key_values`).
|
|
output_attentions (:obj:`bool`, `optional`):
|
|
Whether or not to return the attentions tensors of all attention layers. See ``attentions`` under returned
|
|
tensors for more detail.
|
|
output_hidden_states (:obj:`bool`, `optional`):
|
|
Whether or not to return the hidden states of all layers. See ``hidden_states`` under returned tensors for
|
|
more detail.
|
|
return_dict (:obj:`bool`, `optional`):
|
|
Whether or not to return a :class:`~transformers.file_utils.ModelOutput` instead of a plain tuple.
|
|
"""
|
|
|
|
|
|
@add_start_docstrings(
|
|
"The bare CTRL Model transformer outputting raw hidden-states without any specific head on top.",
|
|
CTRL_START_DOCSTRING,
|
|
)
|
|
class CTRLModel(CTRLPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
|
|
self.d_model_size = config.n_embd
|
|
self.num_layers = config.n_layer
|
|
|
|
self.pos_encoding = positional_encoding(config.n_positions, self.d_model_size, torch.float)
|
|
|
|
self.w = nn.Embedding(config.vocab_size, config.n_embd)
|
|
|
|
self.dropout = nn.Dropout(config.embd_pdrop)
|
|
self.h = nn.ModuleList(
|
|
[EncoderLayer(config.n_embd, config.n_head, config.dff, config.resid_pdrop) for _ in range(config.n_layer)]
|
|
)
|
|
self.layernorm = nn.LayerNorm(config.n_embd, eps=config.layer_norm_epsilon)
|
|
|
|
self.init_weights()
|
|
|
|
def get_input_embeddings(self):
|
|
return self.w
|
|
|
|
def set_input_embeddings(self, new_embeddings):
|
|
self.w = new_embeddings
|
|
|
|
def _prune_heads(self, heads_to_prune):
|
|
"""
|
|
Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer}
|
|
"""
|
|
for layer, heads in heads_to_prune.items():
|
|
self.h[layer].multi_head_attention.prune_heads(heads)
|
|
|
|
@add_start_docstrings_to_model_forward(CTRL_INPUTS_DOCSTRING)
|
|
@add_code_sample_docstrings(
|
|
tokenizer_class=_TOKENIZER_FOR_DOC,
|
|
checkpoint="ctrl",
|
|
output_type=BaseModelOutputWithPast,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
def forward(
|
|
self,
|
|
input_ids=None,
|
|
past_key_values=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
):
|
|
|
|
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
|
|
use_cache = use_cache if use_cache is not None else self.config.use_cache
|
|
output_hidden_states = (
|
|
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
|
|
)
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
if input_ids is not None and inputs_embeds is not None:
|
|
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
|
|
elif input_ids is not None:
|
|
input_shape = input_ids.size()
|
|
input_ids = input_ids.view(-1, input_shape[-1])
|
|
batch_size = input_ids.shape[0]
|
|
elif inputs_embeds is not None:
|
|
input_shape = inputs_embeds.size()[:-1]
|
|
batch_size = inputs_embeds.shape[0]
|
|
else:
|
|
raise ValueError("You have to specify either input_ids or inputs_embeds")
|
|
|
|
if past_key_values is None:
|
|
past_length = 0
|
|
past_key_values = [None] * len(self.h)
|
|
else:
|
|
past_length = past_key_values[0][0].size(-2)
|
|
if position_ids is None:
|
|
device = input_ids.device if input_ids is not None else inputs_embeds.device
|
|
position_ids = torch.arange(past_length, input_shape[-1] + past_length, dtype=torch.long, device=device)
|
|
position_ids = position_ids.unsqueeze(0).view(-1, input_shape[-1])
|
|
|
|
# Attention mask.
|
|
if attention_mask is not None:
|
|
assert batch_size > 0, "batch_size has to be defined and > 0"
|
|
attention_mask = attention_mask.view(batch_size, -1)
|
|
# We create a 3D attention mask from a 2D tensor mask.
|
|
# Sizes are [batch_size, 1, 1, to_seq_length]
|
|
# So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
|
|
# this attention mask is more simple than the triangular masking of causal attention
|
|
# used in OpenAI GPT, we just need to prepare the broadcast dimension here.
|
|
attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)
|
|
|
|
# Since attention_mask is 1.0 for positions we want to attend and 0.0 for
|
|
# masked positions, this operation will create a tensor which is 0.0 for
|
|
# positions we want to attend and -10000.0 for masked positions.
|
|
# Since we are adding it to the raw scores before the softmax, this is
|
|
# effectively the same as removing these entirely.
|
|
attention_mask = attention_mask.to(dtype=self.dtype) # fp16 compatibility
|
|
attention_mask = (1.0 - attention_mask) * -10000.0
|
|
|
|
# Prepare head mask if needed
|
|
head_mask = self.get_head_mask(head_mask, self.config.n_layer)
|
|
|
|
if token_type_ids is not None:
|
|
token_type_ids = token_type_ids.view(-1, input_shape[-1])
|
|
token_type_embeds = self.w(token_type_ids)
|
|
token_type_embeds *= np.sqrt(self.d_model_size)
|
|
else:
|
|
token_type_embeds = 0
|
|
position_ids = position_ids.view(-1, input_shape[-1])
|
|
|
|
if inputs_embeds is None:
|
|
inputs_embeds = self.w(input_ids)
|
|
# inputs_embeds = embedded.unsqueeze(0) if len(input_ids.shape)<2 else embedded
|
|
seq_len = input_shape[-1]
|
|
mask = torch.triu(torch.ones(seq_len + past_length, seq_len + past_length), 1).to(inputs_embeds.device)
|
|
|
|
inputs_embeds *= np.sqrt(self.d_model_size)
|
|
|
|
pos_embeds = self.pos_encoding[position_ids, :].to(inputs_embeds.device)
|
|
|
|
hidden_states = inputs_embeds + pos_embeds + token_type_embeds
|
|
|
|
hidden_states = self.dropout(hidden_states)
|
|
|
|
presents = () if use_cache else None
|
|
all_hidden_states = () if output_hidden_states else None
|
|
all_attentions = () if output_attentions else None
|
|
for i, (h, layer_past) in enumerate(zip(self.h, past_key_values)):
|
|
if output_hidden_states:
|
|
all_hidden_states = all_hidden_states + (hidden_states,)
|
|
outputs = h(
|
|
hidden_states,
|
|
mask,
|
|
layer_past=layer_past,
|
|
attention_mask=attention_mask,
|
|
head_mask=head_mask[i],
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
)
|
|
hidden_states, present = outputs[:2]
|
|
if use_cache is True:
|
|
presents = presents + (present,)
|
|
|
|
if output_attentions:
|
|
all_attentions += (outputs[2],)
|
|
|
|
hidden_states = self.layernorm(hidden_states)
|
|
if output_hidden_states:
|
|
all_hidden_states = all_hidden_states + (hidden_states,)
|
|
|
|
if not return_dict:
|
|
return tuple(v for v in [hidden_states, presents, all_hidden_states, all_attentions] if v is not None)
|
|
|
|
return BaseModelOutputWithPast(
|
|
last_hidden_state=hidden_states,
|
|
past_key_values=presents,
|
|
hidden_states=all_hidden_states,
|
|
attentions=all_attentions,
|
|
)
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""
|
|
The CTRL Model transformer with a language modeling head on top (linear layer with weights tied to the input
|
|
embeddings).
|
|
""",
|
|
CTRL_START_DOCSTRING,
|
|
)
|
|
class CTRLLMHeadModel(CTRLPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.transformer = CTRLModel(config)
|
|
self.lm_head = nn.Linear(config.n_embd, config.vocab_size, bias=True)
|
|
|
|
self.init_weights()
|
|
|
|
def get_output_embeddings(self):
|
|
return self.lm_head
|
|
|
|
def set_output_embeddings(self, new_embeddings):
|
|
self.lm_head = new_embeddings
|
|
|
|
def prepare_inputs_for_generation(self, input_ids, past=None, use_cache=None, **kwargs):
|
|
# only last token for inputs_ids if past is defined in kwargs
|
|
if past:
|
|
input_ids = input_ids[:, -1].unsqueeze(-1)
|
|
|
|
return {"input_ids": input_ids, "past_key_values": past, "use_cache": use_cache}
|
|
|
|
@add_start_docstrings_to_model_forward(CTRL_INPUTS_DOCSTRING)
|
|
@add_code_sample_docstrings(
|
|
tokenizer_class=_TOKENIZER_FOR_DOC,
|
|
checkpoint="ctrl",
|
|
output_type=CausalLMOutputWithPast,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
def forward(
|
|
self,
|
|
input_ids=None,
|
|
past_key_values=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
labels=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
):
|
|
r"""
|
|
labels (:obj:`torch.LongTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
|
|
Labels for language modeling. Note that the labels **are shifted** inside the model, i.e. you can set
|
|
``labels = input_ids`` Indices are selected in ``[-100, 0, ..., config.vocab_size]`` All labels set to
|
|
``-100`` are ignored (masked), the loss is only computed for labels in ``[0, ..., config.vocab_size]``
|
|
"""
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
transformer_outputs = self.transformer(
|
|
input_ids,
|
|
past_key_values=past_key_values,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
head_mask=head_mask,
|
|
inputs_embeds=inputs_embeds,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
hidden_states = transformer_outputs[0]
|
|
|
|
lm_logits = self.lm_head(hidden_states)
|
|
|
|
loss = None
|
|
if labels is not None:
|
|
# Shift so that tokens < n predict n
|
|
shift_logits = lm_logits[..., :-1, :].contiguous()
|
|
shift_labels = labels[..., 1:].contiguous()
|
|
# Flatten the tokens
|
|
loss_fct = CrossEntropyLoss()
|
|
loss = loss_fct(shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1))
|
|
|
|
if not return_dict:
|
|
output = (lm_logits,) + transformer_outputs[1:]
|
|
return ((loss,) + output) if loss is not None else output
|
|
|
|
return CausalLMOutputWithPast(
|
|
loss=loss,
|
|
logits=lm_logits,
|
|
past_key_values=transformer_outputs.past_key_values,
|
|
hidden_states=transformer_outputs.hidden_states,
|
|
attentions=transformer_outputs.attentions,
|
|
)
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""
|
|
The CTRL Model transformer with a sequence classification head on top (linear layer).
|
|
:class:`~transformers.CTRLForSequenceClassification` uses the last token in order to do the classification, as
|
|
other causal models (e.g. GPT-2) do. Since it does classification on the last token, it requires to know the
|
|
position of the last token. If a :obj:`pad_token_id` is defined in the configuration, it finds the last token that
|
|
is not a padding token in each row. If no :obj:`pad_token_id` is defined, it simply takes the last value in each
|
|
row of the batch. Since it cannot guess the padding tokens when :obj:`inputs_embeds` are passed instead of
|
|
:obj:`input_ids`, it does the same (take the last value in each row of the batch).
|
|
""",
|
|
CTRL_START_DOCSTRING,
|
|
)
|
|
class CTRLForSequenceClassification(CTRLPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.num_labels = config.num_labels
|
|
self.transformer = CTRLModel(config)
|
|
self.classifier = nn.Linear(config.n_embd, self.num_labels, bias=False)
|
|
|
|
self.init_weights()
|
|
|
|
@add_start_docstrings_to_model_forward(CTRL_INPUTS_DOCSTRING)
|
|
@add_code_sample_docstrings(
|
|
tokenizer_class=_TOKENIZER_FOR_DOC,
|
|
checkpoint="ctrl",
|
|
output_type=SequenceClassifierOutput,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
def forward(
|
|
self,
|
|
input_ids=None,
|
|
past_key_values=None,
|
|
attention_mask=None,
|
|
token_type_ids=None,
|
|
position_ids=None,
|
|
head_mask=None,
|
|
inputs_embeds=None,
|
|
labels=None,
|
|
use_cache=None,
|
|
output_attentions=None,
|
|
output_hidden_states=None,
|
|
return_dict=None,
|
|
):
|
|
r"""
|
|
labels (:obj:`torch.LongTensor` of shape :obj:`(batch_size,)`, `optional`):
|
|
Labels for computing the sequence classification/regression loss. Indices should be in :obj:`[0, ...,
|
|
config.num_labels - 1]`. If :obj:`config.num_labels == 1` a regression loss is computed (Mean-Square loss),
|
|
If :obj:`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
|
|
|
|
transformer_outputs = self.transformer(
|
|
input_ids,
|
|
past_key_values=past_key_values,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
head_mask=head_mask,
|
|
inputs_embeds=inputs_embeds,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
hidden_states = transformer_outputs[0]
|
|
logits = self.classifier(hidden_states)
|
|
|
|
if input_ids is not None:
|
|
batch_size, sequence_length = input_ids.shape[:2]
|
|
else:
|
|
batch_size, sequence_length = inputs_embeds.shape[:2]
|
|
|
|
assert (
|
|
self.config.pad_token_id is not None or batch_size == 1
|
|
), "Cannot handle batch sizes > 1 if no padding token is defined."
|
|
|
|
if self.config.pad_token_id is None:
|
|
sequence_lengths = -1
|
|
else:
|
|
if input_ids is not None:
|
|
sequence_lengths = torch.ne(input_ids, self.config.pad_token_id).sum(-1) - 1
|
|
else:
|
|
sequence_lengths = -1
|
|
logger.warning(
|
|
f"{self.__class__.__name__} will not detect padding tokens in `inputs_embeds`. Results may be "
|
|
f"unexpected if using padding tokens in conjuction with `inputs_embeds.`"
|
|
)
|
|
|
|
pooled_logits = logits[range(batch_size), sequence_lengths]
|
|
|
|
loss = None
|
|
if labels is not None:
|
|
if self.num_labels == 1:
|
|
# We are doing regression
|
|
loss_fct = MSELoss()
|
|
loss = loss_fct(pooled_logits.view(-1), labels.to(self.dtype).view(-1))
|
|
else:
|
|
loss_fct = CrossEntropyLoss()
|
|
loss = loss_fct(pooled_logits.view(-1, self.num_labels), labels.view(-1))
|
|
|
|
if not return_dict:
|
|
output = (pooled_logits,) + transformer_outputs[2:]
|
|
return ((loss,) + output) if loss is not None else output
|
|
|
|
return SequenceClassifierOutput(
|
|
loss=loss,
|
|
logits=pooled_logits,
|
|
hidden_states=transformer_outputs.hidden_states,
|
|
attentions=transformer_outputs.attentions,
|
|
)
|