1427 lines
57 KiB
Python
1427 lines
57 KiB
Python
# coding=utf-8
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# Copyright 2020 Microsoft and the Hugging Face Inc. team.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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""" PyTorch DeBERTa model."""
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from collections.abc import Sequence
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from typing import Optional, Tuple, Union
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import torch
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import torch.utils.checkpoint
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from torch import nn
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from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
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from ...activations import ACT2FN
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from ...modeling_outputs import (
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BaseModelOutput,
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MaskedLMOutput,
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QuestionAnsweringModelOutput,
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SequenceClassifierOutput,
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TokenClassifierOutput,
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)
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from ...modeling_utils import PreTrainedModel
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from ...pytorch_utils import softmax_backward_data
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from ...utils import add_code_sample_docstrings, add_start_docstrings, add_start_docstrings_to_model_forward, logging
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from .configuration_deberta import DebertaConfig
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logger = logging.get_logger(__name__)
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_CONFIG_FOR_DOC = "DebertaConfig"
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_CHECKPOINT_FOR_DOC = "microsoft/deberta-base"
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# Masked LM docstring
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_CHECKPOINT_FOR_MASKED_LM = "lsanochkin/deberta-large-feedback"
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_MASKED_LM_EXPECTED_OUTPUT = "' Paris'"
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_MASKED_LM_EXPECTED_LOSS = "0.54"
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# QuestionAnswering docstring
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_CHECKPOINT_FOR_QA = "Palak/microsoft_deberta-large_squad"
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_QA_EXPECTED_OUTPUT = "' a nice puppet'"
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_QA_EXPECTED_LOSS = 0.14
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_QA_TARGET_START_INDEX = 12
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_QA_TARGET_END_INDEX = 14
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from ..deprecated._archive_maps import DEBERTA_PRETRAINED_MODEL_ARCHIVE_LIST # noqa: F401, E402
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class ContextPooler(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.pooler_hidden_size, config.pooler_hidden_size)
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self.dropout = StableDropout(config.pooler_dropout)
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self.config = config
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def forward(self, hidden_states):
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# We "pool" the model by simply taking the hidden state corresponding
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# to the first token.
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context_token = hidden_states[:, 0]
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context_token = self.dropout(context_token)
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pooled_output = self.dense(context_token)
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pooled_output = ACT2FN[self.config.pooler_hidden_act](pooled_output)
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return pooled_output
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@property
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def output_dim(self):
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return self.config.hidden_size
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class XSoftmax(torch.autograd.Function):
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"""
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Masked Softmax which is optimized for saving memory
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Args:
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input (`torch.tensor`): The input tensor that will apply softmax.
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mask (`torch.IntTensor`):
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The mask matrix where 0 indicate that element will be ignored in the softmax calculation.
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dim (int): The dimension that will apply softmax
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Example:
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```python
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>>> import torch
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>>> from transformers.models.deberta.modeling_deberta import XSoftmax
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>>> # Make a tensor
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>>> x = torch.randn([4, 20, 100])
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>>> # Create a mask
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>>> mask = (x > 0).int()
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>>> # Specify the dimension to apply softmax
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>>> dim = -1
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>>> y = XSoftmax.apply(x, mask, dim)
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```"""
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@staticmethod
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def forward(self, input, mask, dim):
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self.dim = dim
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rmask = ~(mask.to(torch.bool))
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output = input.masked_fill(rmask, torch.tensor(torch.finfo(input.dtype).min))
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output = torch.softmax(output, self.dim)
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output.masked_fill_(rmask, 0)
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self.save_for_backward(output)
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return output
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@staticmethod
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def backward(self, grad_output):
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(output,) = self.saved_tensors
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inputGrad = softmax_backward_data(self, grad_output, output, self.dim, output)
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return inputGrad, None, None
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@staticmethod
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def symbolic(g, self, mask, dim):
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import torch.onnx.symbolic_helper as sym_help
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from torch.onnx.symbolic_opset9 import masked_fill, softmax
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mask_cast_value = g.op("Cast", mask, to_i=sym_help.cast_pytorch_to_onnx["Long"])
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r_mask = g.op(
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"Cast",
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g.op("Sub", g.op("Constant", value_t=torch.tensor(1, dtype=torch.int64)), mask_cast_value),
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to_i=sym_help.cast_pytorch_to_onnx["Bool"],
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)
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output = masked_fill(
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g, self, r_mask, g.op("Constant", value_t=torch.tensor(torch.finfo(self.type().dtype()).min))
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)
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output = softmax(g, output, dim)
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return masked_fill(g, output, r_mask, g.op("Constant", value_t=torch.tensor(0, dtype=torch.bool)))
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class DropoutContext(object):
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def __init__(self):
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self.dropout = 0
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self.mask = None
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self.scale = 1
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self.reuse_mask = True
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def get_mask(input, local_context):
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if not isinstance(local_context, DropoutContext):
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dropout = local_context
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mask = None
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else:
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dropout = local_context.dropout
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dropout *= local_context.scale
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mask = local_context.mask if local_context.reuse_mask else None
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if dropout > 0 and mask is None:
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mask = (1 - torch.empty_like(input).bernoulli_(1 - dropout)).to(torch.bool)
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if isinstance(local_context, DropoutContext):
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if local_context.mask is None:
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local_context.mask = mask
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return mask, dropout
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class XDropout(torch.autograd.Function):
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"""Optimized dropout function to save computation and memory by using mask operation instead of multiplication."""
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@staticmethod
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def forward(ctx, input, local_ctx):
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mask, dropout = get_mask(input, local_ctx)
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ctx.scale = 1.0 / (1 - dropout)
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if dropout > 0:
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ctx.save_for_backward(mask)
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return input.masked_fill(mask, 0) * ctx.scale
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else:
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return input
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@staticmethod
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def backward(ctx, grad_output):
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if ctx.scale > 1:
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(mask,) = ctx.saved_tensors
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return grad_output.masked_fill(mask, 0) * ctx.scale, None
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else:
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return grad_output, None
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@staticmethod
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def symbolic(g: torch._C.Graph, input: torch._C.Value, local_ctx: Union[float, DropoutContext]) -> torch._C.Value:
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from torch.onnx import symbolic_opset12
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dropout_p = local_ctx
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if isinstance(local_ctx, DropoutContext):
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dropout_p = local_ctx.dropout
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# StableDropout only calls this function when training.
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train = True
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# TODO: We should check if the opset_version being used to export
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# is > 12 here, but there's no good way to do that. As-is, if the
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# opset_version < 12, export will fail with a CheckerError.
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# Once https://github.com/pytorch/pytorch/issues/78391 is fixed, do something like:
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# if opset_version < 12:
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# return torch.onnx.symbolic_opset9.dropout(g, input, dropout_p, train)
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return symbolic_opset12.dropout(g, input, dropout_p, train)
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class StableDropout(nn.Module):
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"""
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Optimized dropout module for stabilizing the training
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Args:
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drop_prob (float): the dropout probabilities
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"""
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def __init__(self, drop_prob):
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super().__init__()
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self.drop_prob = drop_prob
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self.count = 0
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self.context_stack = None
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def forward(self, x):
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"""
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Call the module
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Args:
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x (`torch.tensor`): The input tensor to apply dropout
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"""
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if self.training and self.drop_prob > 0:
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return XDropout.apply(x, self.get_context())
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return x
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def clear_context(self):
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self.count = 0
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self.context_stack = None
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def init_context(self, reuse_mask=True, scale=1):
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if self.context_stack is None:
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self.context_stack = []
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self.count = 0
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for c in self.context_stack:
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c.reuse_mask = reuse_mask
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c.scale = scale
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def get_context(self):
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if self.context_stack is not None:
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if self.count >= len(self.context_stack):
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self.context_stack.append(DropoutContext())
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ctx = self.context_stack[self.count]
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ctx.dropout = self.drop_prob
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self.count += 1
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return ctx
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else:
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return self.drop_prob
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class DebertaLayerNorm(nn.Module):
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"""LayerNorm module in the TF style (epsilon inside the square root)."""
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def __init__(self, size, eps=1e-12):
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super().__init__()
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self.weight = nn.Parameter(torch.ones(size))
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self.bias = nn.Parameter(torch.zeros(size))
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self.variance_epsilon = eps
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def forward(self, hidden_states):
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input_type = hidden_states.dtype
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hidden_states = hidden_states.float()
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mean = hidden_states.mean(-1, keepdim=True)
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variance = (hidden_states - mean).pow(2).mean(-1, keepdim=True)
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hidden_states = (hidden_states - mean) / torch.sqrt(variance + self.variance_epsilon)
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hidden_states = hidden_states.to(input_type)
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y = self.weight * hidden_states + self.bias
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return y
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class DebertaSelfOutput(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.hidden_size, config.hidden_size)
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self.LayerNorm = DebertaLayerNorm(config.hidden_size, config.layer_norm_eps)
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self.dropout = StableDropout(config.hidden_dropout_prob)
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def forward(self, hidden_states, input_tensor):
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hidden_states = self.dense(hidden_states)
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hidden_states = self.dropout(hidden_states)
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hidden_states = self.LayerNorm(hidden_states + input_tensor)
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return hidden_states
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class DebertaAttention(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.self = DisentangledSelfAttention(config)
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self.output = DebertaSelfOutput(config)
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self.config = config
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def forward(
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self,
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hidden_states,
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attention_mask,
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output_attentions=False,
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query_states=None,
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relative_pos=None,
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rel_embeddings=None,
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):
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self_output = self.self(
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hidden_states,
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attention_mask,
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output_attentions,
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query_states=query_states,
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relative_pos=relative_pos,
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rel_embeddings=rel_embeddings,
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)
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if output_attentions:
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self_output, att_matrix = self_output
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if query_states is None:
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query_states = hidden_states
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attention_output = self.output(self_output, query_states)
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if output_attentions:
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return (attention_output, att_matrix)
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else:
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return attention_output
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# Copied from transformers.models.bert.modeling_bert.BertIntermediate with Bert->Deberta
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class DebertaIntermediate(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.hidden_size, config.intermediate_size)
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if isinstance(config.hidden_act, str):
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self.intermediate_act_fn = ACT2FN[config.hidden_act]
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else:
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self.intermediate_act_fn = config.hidden_act
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def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
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hidden_states = self.dense(hidden_states)
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hidden_states = self.intermediate_act_fn(hidden_states)
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return hidden_states
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class DebertaOutput(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.dense = nn.Linear(config.intermediate_size, config.hidden_size)
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self.LayerNorm = DebertaLayerNorm(config.hidden_size, config.layer_norm_eps)
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self.dropout = StableDropout(config.hidden_dropout_prob)
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self.config = config
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def forward(self, hidden_states, input_tensor):
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hidden_states = self.dense(hidden_states)
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hidden_states = self.dropout(hidden_states)
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hidden_states = self.LayerNorm(hidden_states + input_tensor)
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return hidden_states
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class DebertaLayer(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.attention = DebertaAttention(config)
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self.intermediate = DebertaIntermediate(config)
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self.output = DebertaOutput(config)
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def forward(
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self,
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hidden_states,
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attention_mask,
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query_states=None,
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relative_pos=None,
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rel_embeddings=None,
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output_attentions=False,
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):
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attention_output = self.attention(
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hidden_states,
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attention_mask,
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output_attentions=output_attentions,
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query_states=query_states,
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relative_pos=relative_pos,
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rel_embeddings=rel_embeddings,
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)
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if output_attentions:
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attention_output, att_matrix = attention_output
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intermediate_output = self.intermediate(attention_output)
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layer_output = self.output(intermediate_output, attention_output)
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if output_attentions:
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return (layer_output, att_matrix)
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else:
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return layer_output
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class DebertaEncoder(nn.Module):
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"""Modified BertEncoder with relative position bias support"""
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def __init__(self, config):
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super().__init__()
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self.layer = nn.ModuleList([DebertaLayer(config) for _ in range(config.num_hidden_layers)])
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self.relative_attention = getattr(config, "relative_attention", False)
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if self.relative_attention:
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self.max_relative_positions = getattr(config, "max_relative_positions", -1)
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if self.max_relative_positions < 1:
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self.max_relative_positions = config.max_position_embeddings
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self.rel_embeddings = nn.Embedding(self.max_relative_positions * 2, config.hidden_size)
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self.gradient_checkpointing = False
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def get_rel_embedding(self):
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rel_embeddings = self.rel_embeddings.weight if self.relative_attention else None
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return rel_embeddings
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def get_attention_mask(self, attention_mask):
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if attention_mask.dim() <= 2:
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extended_attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)
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attention_mask = extended_attention_mask * extended_attention_mask.squeeze(-2).unsqueeze(-1)
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elif attention_mask.dim() == 3:
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attention_mask = attention_mask.unsqueeze(1)
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return attention_mask
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def get_rel_pos(self, hidden_states, query_states=None, relative_pos=None):
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if self.relative_attention and relative_pos is None:
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q = query_states.size(-2) if query_states is not None else hidden_states.size(-2)
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relative_pos = build_relative_position(q, hidden_states.size(-2), hidden_states.device)
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return relative_pos
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def forward(
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self,
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hidden_states,
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attention_mask,
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output_hidden_states=True,
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output_attentions=False,
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query_states=None,
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relative_pos=None,
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return_dict=True,
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):
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attention_mask = self.get_attention_mask(attention_mask)
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relative_pos = self.get_rel_pos(hidden_states, query_states, relative_pos)
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all_hidden_states = () if output_hidden_states else None
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all_attentions = () if output_attentions else None
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if isinstance(hidden_states, Sequence):
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next_kv = hidden_states[0]
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else:
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next_kv = hidden_states
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rel_embeddings = self.get_rel_embedding()
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for i, layer_module in enumerate(self.layer):
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if output_hidden_states:
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all_hidden_states = all_hidden_states + (hidden_states,)
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if self.gradient_checkpointing and self.training:
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hidden_states = self._gradient_checkpointing_func(
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layer_module.__call__,
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next_kv,
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attention_mask,
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query_states,
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relative_pos,
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rel_embeddings,
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output_attentions,
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)
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else:
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hidden_states = layer_module(
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next_kv,
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attention_mask,
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query_states=query_states,
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relative_pos=relative_pos,
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rel_embeddings=rel_embeddings,
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output_attentions=output_attentions,
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)
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if output_attentions:
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hidden_states, att_m = hidden_states
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if query_states is not None:
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query_states = hidden_states
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if isinstance(hidden_states, Sequence):
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next_kv = hidden_states[i + 1] if i + 1 < len(self.layer) else None
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else:
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next_kv = hidden_states
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if output_attentions:
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all_attentions = all_attentions + (att_m,)
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if output_hidden_states:
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all_hidden_states = all_hidden_states + (hidden_states,)
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if not return_dict:
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return tuple(v for v in [hidden_states, all_hidden_states, all_attentions] if v is not None)
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return BaseModelOutput(
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last_hidden_state=hidden_states, hidden_states=all_hidden_states, attentions=all_attentions
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)
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def build_relative_position(query_size, key_size, device):
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"""
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Build relative position according to the query and key
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We assume the absolute position of query \\(P_q\\) is range from (0, query_size) and the absolute position of key
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\\(P_k\\) is range from (0, key_size), The relative positions from query to key is \\(R_{q \\rightarrow k} = P_q -
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P_k\\)
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Args:
|
|
query_size (int): the length of query
|
|
key_size (int): the length of key
|
|
|
|
Return:
|
|
`torch.LongTensor`: A tensor with shape [1, query_size, key_size]
|
|
|
|
"""
|
|
|
|
q_ids = torch.arange(query_size, dtype=torch.long, device=device)
|
|
k_ids = torch.arange(key_size, dtype=torch.long, device=device)
|
|
rel_pos_ids = q_ids[:, None] - k_ids.view(1, -1).repeat(query_size, 1)
|
|
rel_pos_ids = rel_pos_ids[:query_size, :]
|
|
rel_pos_ids = rel_pos_ids.unsqueeze(0)
|
|
return rel_pos_ids
|
|
|
|
|
|
@torch.jit.script
|
|
def c2p_dynamic_expand(c2p_pos, query_layer, relative_pos):
|
|
return c2p_pos.expand([query_layer.size(0), query_layer.size(1), query_layer.size(2), relative_pos.size(-1)])
|
|
|
|
|
|
@torch.jit.script
|
|
def p2c_dynamic_expand(c2p_pos, query_layer, key_layer):
|
|
return c2p_pos.expand([query_layer.size(0), query_layer.size(1), key_layer.size(-2), key_layer.size(-2)])
|
|
|
|
|
|
@torch.jit.script
|
|
def pos_dynamic_expand(pos_index, p2c_att, key_layer):
|
|
return pos_index.expand(p2c_att.size()[:2] + (pos_index.size(-2), key_layer.size(-2)))
|
|
|
|
|
|
class DisentangledSelfAttention(nn.Module):
|
|
"""
|
|
Disentangled self-attention module
|
|
|
|
Parameters:
|
|
config (`str`):
|
|
A model config class instance with the configuration to build a new model. The schema is similar to
|
|
*BertConfig*, for more details, please refer [`DebertaConfig`]
|
|
|
|
"""
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
if config.hidden_size % config.num_attention_heads != 0:
|
|
raise ValueError(
|
|
f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention "
|
|
f"heads ({config.num_attention_heads})"
|
|
)
|
|
self.num_attention_heads = config.num_attention_heads
|
|
self.attention_head_size = int(config.hidden_size / config.num_attention_heads)
|
|
self.all_head_size = self.num_attention_heads * self.attention_head_size
|
|
self.in_proj = nn.Linear(config.hidden_size, self.all_head_size * 3, bias=False)
|
|
self.q_bias = nn.Parameter(torch.zeros((self.all_head_size), dtype=torch.float))
|
|
self.v_bias = nn.Parameter(torch.zeros((self.all_head_size), dtype=torch.float))
|
|
self.pos_att_type = config.pos_att_type if config.pos_att_type is not None else []
|
|
|
|
self.relative_attention = getattr(config, "relative_attention", False)
|
|
self.talking_head = getattr(config, "talking_head", False)
|
|
|
|
if self.talking_head:
|
|
self.head_logits_proj = nn.Linear(config.num_attention_heads, config.num_attention_heads, bias=False)
|
|
self.head_weights_proj = nn.Linear(config.num_attention_heads, config.num_attention_heads, bias=False)
|
|
|
|
if self.relative_attention:
|
|
self.max_relative_positions = getattr(config, "max_relative_positions", -1)
|
|
if self.max_relative_positions < 1:
|
|
self.max_relative_positions = config.max_position_embeddings
|
|
self.pos_dropout = StableDropout(config.hidden_dropout_prob)
|
|
|
|
if "c2p" in self.pos_att_type:
|
|
self.pos_proj = nn.Linear(config.hidden_size, self.all_head_size, bias=False)
|
|
if "p2c" in self.pos_att_type:
|
|
self.pos_q_proj = nn.Linear(config.hidden_size, self.all_head_size)
|
|
|
|
self.dropout = StableDropout(config.attention_probs_dropout_prob)
|
|
|
|
def transpose_for_scores(self, x):
|
|
new_x_shape = x.size()[:-1] + (self.num_attention_heads, -1)
|
|
x = x.view(new_x_shape)
|
|
return x.permute(0, 2, 1, 3)
|
|
|
|
def forward(
|
|
self,
|
|
hidden_states,
|
|
attention_mask,
|
|
output_attentions=False,
|
|
query_states=None,
|
|
relative_pos=None,
|
|
rel_embeddings=None,
|
|
):
|
|
"""
|
|
Call the module
|
|
|
|
Args:
|
|
hidden_states (`torch.FloatTensor`):
|
|
Input states to the module usually the output from previous layer, it will be the Q,K and V in
|
|
*Attention(Q,K,V)*
|
|
|
|
attention_mask (`torch.BoolTensor`):
|
|
An attention mask matrix of shape [*B*, *N*, *N*] where *B* is the batch size, *N* is the maximum
|
|
sequence length in which element [i,j] = *1* means the *i* th token in the input can attend to the *j*
|
|
th token.
|
|
|
|
output_attentions (`bool`, optional):
|
|
Whether return the attention matrix.
|
|
|
|
query_states (`torch.FloatTensor`, optional):
|
|
The *Q* state in *Attention(Q,K,V)*.
|
|
|
|
relative_pos (`torch.LongTensor`):
|
|
The relative position encoding between the tokens in the sequence. It's of shape [*B*, *N*, *N*] with
|
|
values ranging in [*-max_relative_positions*, *max_relative_positions*].
|
|
|
|
rel_embeddings (`torch.FloatTensor`):
|
|
The embedding of relative distances. It's a tensor of shape [\\(2 \\times
|
|
\\text{max_relative_positions}\\), *hidden_size*].
|
|
|
|
|
|
"""
|
|
if query_states is None:
|
|
qp = self.in_proj(hidden_states) # .split(self.all_head_size, dim=-1)
|
|
query_layer, key_layer, value_layer = self.transpose_for_scores(qp).chunk(3, dim=-1)
|
|
else:
|
|
|
|
def linear(w, b, x):
|
|
if b is not None:
|
|
return torch.matmul(x, w.t()) + b.t()
|
|
else:
|
|
return torch.matmul(x, w.t()) # + b.t()
|
|
|
|
ws = self.in_proj.weight.chunk(self.num_attention_heads * 3, dim=0)
|
|
qkvw = [torch.cat([ws[i * 3 + k] for i in range(self.num_attention_heads)], dim=0) for k in range(3)]
|
|
qkvb = [None] * 3
|
|
|
|
q = linear(qkvw[0], qkvb[0], query_states.to(dtype=qkvw[0].dtype))
|
|
k, v = [linear(qkvw[i], qkvb[i], hidden_states.to(dtype=qkvw[i].dtype)) for i in range(1, 3)]
|
|
query_layer, key_layer, value_layer = [self.transpose_for_scores(x) for x in [q, k, v]]
|
|
|
|
query_layer = query_layer + self.transpose_for_scores(self.q_bias[None, None, :])
|
|
value_layer = value_layer + self.transpose_for_scores(self.v_bias[None, None, :])
|
|
|
|
rel_att = None
|
|
# Take the dot product between "query" and "key" to get the raw attention scores.
|
|
scale_factor = 1 + len(self.pos_att_type)
|
|
scale = torch.sqrt(torch.tensor(query_layer.size(-1), dtype=torch.float) * scale_factor)
|
|
query_layer = query_layer / scale.to(dtype=query_layer.dtype)
|
|
attention_scores = torch.matmul(query_layer, key_layer.transpose(-1, -2))
|
|
if self.relative_attention:
|
|
rel_embeddings = self.pos_dropout(rel_embeddings)
|
|
rel_att = self.disentangled_att_bias(query_layer, key_layer, relative_pos, rel_embeddings, scale_factor)
|
|
|
|
if rel_att is not None:
|
|
attention_scores = attention_scores + rel_att
|
|
|
|
# bxhxlxd
|
|
if self.talking_head:
|
|
attention_scores = self.head_logits_proj(attention_scores.permute(0, 2, 3, 1)).permute(0, 3, 1, 2)
|
|
|
|
attention_probs = XSoftmax.apply(attention_scores, attention_mask, -1)
|
|
attention_probs = self.dropout(attention_probs)
|
|
if self.talking_head:
|
|
attention_probs = self.head_weights_proj(attention_probs.permute(0, 2, 3, 1)).permute(0, 3, 1, 2)
|
|
|
|
context_layer = torch.matmul(attention_probs, value_layer)
|
|
context_layer = context_layer.permute(0, 2, 1, 3).contiguous()
|
|
new_context_layer_shape = context_layer.size()[:-2] + (-1,)
|
|
context_layer = context_layer.view(new_context_layer_shape)
|
|
if output_attentions:
|
|
return (context_layer, attention_probs)
|
|
else:
|
|
return context_layer
|
|
|
|
def disentangled_att_bias(self, query_layer, key_layer, relative_pos, rel_embeddings, scale_factor):
|
|
if relative_pos is None:
|
|
q = query_layer.size(-2)
|
|
relative_pos = build_relative_position(q, key_layer.size(-2), query_layer.device)
|
|
if relative_pos.dim() == 2:
|
|
relative_pos = relative_pos.unsqueeze(0).unsqueeze(0)
|
|
elif relative_pos.dim() == 3:
|
|
relative_pos = relative_pos.unsqueeze(1)
|
|
# bxhxqxk
|
|
elif relative_pos.dim() != 4:
|
|
raise ValueError(f"Relative position ids must be of dim 2 or 3 or 4. {relative_pos.dim()}")
|
|
|
|
att_span = min(max(query_layer.size(-2), key_layer.size(-2)), self.max_relative_positions)
|
|
relative_pos = relative_pos.long().to(query_layer.device)
|
|
rel_embeddings = rel_embeddings[
|
|
self.max_relative_positions - att_span : self.max_relative_positions + att_span, :
|
|
].unsqueeze(0)
|
|
|
|
score = 0
|
|
|
|
# content->position
|
|
if "c2p" in self.pos_att_type:
|
|
pos_key_layer = self.pos_proj(rel_embeddings)
|
|
pos_key_layer = self.transpose_for_scores(pos_key_layer)
|
|
c2p_att = torch.matmul(query_layer, pos_key_layer.transpose(-1, -2))
|
|
c2p_pos = torch.clamp(relative_pos + att_span, 0, att_span * 2 - 1)
|
|
c2p_att = torch.gather(c2p_att, dim=-1, index=c2p_dynamic_expand(c2p_pos, query_layer, relative_pos))
|
|
score += c2p_att
|
|
|
|
# position->content
|
|
if "p2c" in self.pos_att_type:
|
|
pos_query_layer = self.pos_q_proj(rel_embeddings)
|
|
pos_query_layer = self.transpose_for_scores(pos_query_layer)
|
|
pos_query_layer /= torch.sqrt(torch.tensor(pos_query_layer.size(-1), dtype=torch.float) * scale_factor)
|
|
if query_layer.size(-2) != key_layer.size(-2):
|
|
r_pos = build_relative_position(key_layer.size(-2), key_layer.size(-2), query_layer.device)
|
|
else:
|
|
r_pos = relative_pos
|
|
p2c_pos = torch.clamp(-r_pos + att_span, 0, att_span * 2 - 1)
|
|
p2c_att = torch.matmul(key_layer, pos_query_layer.transpose(-1, -2).to(dtype=key_layer.dtype))
|
|
p2c_att = torch.gather(
|
|
p2c_att, dim=-1, index=p2c_dynamic_expand(p2c_pos, query_layer, key_layer)
|
|
).transpose(-1, -2)
|
|
|
|
if query_layer.size(-2) != key_layer.size(-2):
|
|
pos_index = relative_pos[:, :, :, 0].unsqueeze(-1)
|
|
p2c_att = torch.gather(p2c_att, dim=-2, index=pos_dynamic_expand(pos_index, p2c_att, key_layer))
|
|
score += p2c_att
|
|
|
|
return score
|
|
|
|
|
|
class DebertaEmbeddings(nn.Module):
|
|
"""Construct the embeddings from word, position and token_type embeddings."""
|
|
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
pad_token_id = getattr(config, "pad_token_id", 0)
|
|
self.embedding_size = getattr(config, "embedding_size", config.hidden_size)
|
|
self.word_embeddings = nn.Embedding(config.vocab_size, self.embedding_size, padding_idx=pad_token_id)
|
|
|
|
self.position_biased_input = getattr(config, "position_biased_input", True)
|
|
if not self.position_biased_input:
|
|
self.position_embeddings = None
|
|
else:
|
|
self.position_embeddings = nn.Embedding(config.max_position_embeddings, self.embedding_size)
|
|
|
|
if config.type_vocab_size > 0:
|
|
self.token_type_embeddings = nn.Embedding(config.type_vocab_size, self.embedding_size)
|
|
|
|
if self.embedding_size != config.hidden_size:
|
|
self.embed_proj = nn.Linear(self.embedding_size, config.hidden_size, bias=False)
|
|
self.LayerNorm = DebertaLayerNorm(config.hidden_size, config.layer_norm_eps)
|
|
self.dropout = StableDropout(config.hidden_dropout_prob)
|
|
self.config = config
|
|
|
|
# position_ids (1, len position emb) is contiguous in memory and exported when serialized
|
|
self.register_buffer(
|
|
"position_ids", torch.arange(config.max_position_embeddings).expand((1, -1)), persistent=False
|
|
)
|
|
|
|
def forward(self, input_ids=None, token_type_ids=None, position_ids=None, mask=None, inputs_embeds=None):
|
|
if input_ids is not None:
|
|
input_shape = input_ids.size()
|
|
else:
|
|
input_shape = inputs_embeds.size()[:-1]
|
|
|
|
seq_length = input_shape[1]
|
|
|
|
if position_ids is None:
|
|
position_ids = self.position_ids[:, :seq_length]
|
|
|
|
if token_type_ids is None:
|
|
token_type_ids = torch.zeros(input_shape, dtype=torch.long, device=self.position_ids.device)
|
|
|
|
if inputs_embeds is None:
|
|
inputs_embeds = self.word_embeddings(input_ids)
|
|
|
|
if self.position_embeddings is not None:
|
|
position_embeddings = self.position_embeddings(position_ids.long())
|
|
else:
|
|
position_embeddings = torch.zeros_like(inputs_embeds)
|
|
|
|
embeddings = inputs_embeds
|
|
if self.position_biased_input:
|
|
embeddings += position_embeddings
|
|
if self.config.type_vocab_size > 0:
|
|
token_type_embeddings = self.token_type_embeddings(token_type_ids)
|
|
embeddings += token_type_embeddings
|
|
|
|
if self.embedding_size != self.config.hidden_size:
|
|
embeddings = self.embed_proj(embeddings)
|
|
|
|
embeddings = self.LayerNorm(embeddings)
|
|
|
|
if mask is not None:
|
|
if mask.dim() != embeddings.dim():
|
|
if mask.dim() == 4:
|
|
mask = mask.squeeze(1).squeeze(1)
|
|
mask = mask.unsqueeze(2)
|
|
mask = mask.to(embeddings.dtype)
|
|
|
|
embeddings = embeddings * mask
|
|
|
|
embeddings = self.dropout(embeddings)
|
|
return embeddings
|
|
|
|
|
|
class DebertaPreTrainedModel(PreTrainedModel):
|
|
"""
|
|
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
|
|
models.
|
|
"""
|
|
|
|
config_class = DebertaConfig
|
|
base_model_prefix = "deberta"
|
|
_keys_to_ignore_on_load_unexpected = ["position_embeddings"]
|
|
supports_gradient_checkpointing = True
|
|
|
|
def _init_weights(self, module):
|
|
"""Initialize the weights."""
|
|
if isinstance(module, nn.Linear):
|
|
# 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 module.bias is not None:
|
|
module.bias.data.zero_()
|
|
elif isinstance(module, nn.Embedding):
|
|
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
|
|
if module.padding_idx is not None:
|
|
module.weight.data[module.padding_idx].zero_()
|
|
|
|
|
|
DEBERTA_START_DOCSTRING = r"""
|
|
The DeBERTa model was proposed in [DeBERTa: Decoding-enhanced BERT with Disentangled
|
|
Attention](https://arxiv.org/abs/2006.03654) by Pengcheng He, Xiaodong Liu, Jianfeng Gao, Weizhu Chen. It's build
|
|
on top of BERT/RoBERTa with two improvements, i.e. disentangled attention and enhanced mask decoder. With those two
|
|
improvements, it out perform BERT/RoBERTa on a majority of tasks with 80GB pretraining data.
|
|
|
|
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 ([`DebertaConfig`]): 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 [`~PreTrainedModel.from_pretrained`] method to load the model weights.
|
|
"""
|
|
|
|
DEBERTA_INPUTS_DOCSTRING = r"""
|
|
Args:
|
|
input_ids (`torch.LongTensor` of shape `({0})`):
|
|
Indices of input sequence tokens in the vocabulary.
|
|
|
|
Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
|
|
[`PreTrainedTokenizer.__call__`] for details.
|
|
|
|
[What are input IDs?](../glossary#input-ids)
|
|
attention_mask (`torch.FloatTensor` of shape `({0})`, *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#attention-mask)
|
|
token_type_ids (`torch.LongTensor` of shape `({0})`, *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#token-type-ids)
|
|
position_ids (`torch.LongTensor` of shape `({0})`, *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#position-ids)
|
|
inputs_embeds (`torch.FloatTensor` of shape `({0}, hidden_size)`, *optional*):
|
|
Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
|
|
is useful if you want more control over how to convert *input_ids* indices into associated vectors than the
|
|
model's internal embedding lookup matrix.
|
|
output_attentions (`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 (`bool`, *optional*):
|
|
Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
|
|
more detail.
|
|
return_dict (`bool`, *optional*):
|
|
Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple.
|
|
"""
|
|
|
|
|
|
@add_start_docstrings(
|
|
"The bare DeBERTa Model transformer outputting raw hidden-states without any specific head on top.",
|
|
DEBERTA_START_DOCSTRING,
|
|
)
|
|
class DebertaModel(DebertaPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
|
|
self.embeddings = DebertaEmbeddings(config)
|
|
self.encoder = DebertaEncoder(config)
|
|
self.z_steps = 0
|
|
self.config = config
|
|
# Initialize weights and apply final processing
|
|
self.post_init()
|
|
|
|
def get_input_embeddings(self):
|
|
return self.embeddings.word_embeddings
|
|
|
|
def set_input_embeddings(self, new_embeddings):
|
|
self.embeddings.word_embeddings = 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} See base
|
|
class PreTrainedModel
|
|
"""
|
|
raise NotImplementedError("The prune function is not implemented in DeBERTa model.")
|
|
|
|
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
|
|
@add_code_sample_docstrings(
|
|
checkpoint=_CHECKPOINT_FOR_DOC,
|
|
output_type=BaseModelOutput,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
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,
|
|
inputs_embeds: Optional[torch.Tensor] = None,
|
|
output_attentions: Optional[bool] = None,
|
|
output_hidden_states: Optional[bool] = None,
|
|
return_dict: Optional[bool] = None,
|
|
) -> Union[Tuple, BaseModelOutput]:
|
|
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
|
|
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:
|
|
self.warn_if_padding_and_no_attention_mask(input_ids, attention_mask)
|
|
input_shape = input_ids.size()
|
|
elif inputs_embeds is not None:
|
|
input_shape = inputs_embeds.size()[:-1]
|
|
else:
|
|
raise ValueError("You have to specify either input_ids or inputs_embeds")
|
|
|
|
device = input_ids.device if input_ids is not None else inputs_embeds.device
|
|
|
|
if attention_mask is None:
|
|
attention_mask = torch.ones(input_shape, device=device)
|
|
if token_type_ids is None:
|
|
token_type_ids = torch.zeros(input_shape, dtype=torch.long, device=device)
|
|
|
|
embedding_output = self.embeddings(
|
|
input_ids=input_ids,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
mask=attention_mask,
|
|
inputs_embeds=inputs_embeds,
|
|
)
|
|
|
|
encoder_outputs = self.encoder(
|
|
embedding_output,
|
|
attention_mask,
|
|
output_hidden_states=True,
|
|
output_attentions=output_attentions,
|
|
return_dict=return_dict,
|
|
)
|
|
encoded_layers = encoder_outputs[1]
|
|
|
|
if self.z_steps > 1:
|
|
hidden_states = encoded_layers[-2]
|
|
layers = [self.encoder.layer[-1] for _ in range(self.z_steps)]
|
|
query_states = encoded_layers[-1]
|
|
rel_embeddings = self.encoder.get_rel_embedding()
|
|
attention_mask = self.encoder.get_attention_mask(attention_mask)
|
|
rel_pos = self.encoder.get_rel_pos(embedding_output)
|
|
for layer in layers[1:]:
|
|
query_states = layer(
|
|
hidden_states,
|
|
attention_mask,
|
|
output_attentions=False,
|
|
query_states=query_states,
|
|
relative_pos=rel_pos,
|
|
rel_embeddings=rel_embeddings,
|
|
)
|
|
encoded_layers.append(query_states)
|
|
|
|
sequence_output = encoded_layers[-1]
|
|
|
|
if not return_dict:
|
|
return (sequence_output,) + encoder_outputs[(1 if output_hidden_states else 2) :]
|
|
|
|
return BaseModelOutput(
|
|
last_hidden_state=sequence_output,
|
|
hidden_states=encoder_outputs.hidden_states if output_hidden_states else None,
|
|
attentions=encoder_outputs.attentions,
|
|
)
|
|
|
|
|
|
@add_start_docstrings("""DeBERTa Model with a `language modeling` head on top.""", DEBERTA_START_DOCSTRING)
|
|
class DebertaForMaskedLM(DebertaPreTrainedModel):
|
|
_tied_weights_keys = ["cls.predictions.decoder.weight", "cls.predictions.decoder.bias"]
|
|
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
|
|
self.deberta = DebertaModel(config)
|
|
self.cls = DebertaOnlyMLMHead(config)
|
|
|
|
# Initialize weights and apply final processing
|
|
self.post_init()
|
|
|
|
def get_output_embeddings(self):
|
|
return self.cls.predictions.decoder
|
|
|
|
def set_output_embeddings(self, new_embeddings):
|
|
self.cls.predictions.decoder = new_embeddings
|
|
|
|
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
|
|
@add_code_sample_docstrings(
|
|
checkpoint=_CHECKPOINT_FOR_MASKED_LM,
|
|
output_type=MaskedLMOutput,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
mask="[MASK]",
|
|
expected_output=_MASKED_LM_EXPECTED_OUTPUT,
|
|
expected_loss=_MASKED_LM_EXPECTED_LOSS,
|
|
)
|
|
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,
|
|
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, MaskedLMOutput]:
|
|
r"""
|
|
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
|
|
Labels 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]`
|
|
"""
|
|
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
outputs = self.deberta(
|
|
input_ids,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
inputs_embeds=inputs_embeds,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
sequence_output = outputs[0]
|
|
prediction_scores = self.cls(sequence_output)
|
|
|
|
masked_lm_loss = None
|
|
if labels is not None:
|
|
loss_fct = CrossEntropyLoss() # -100 index = padding token
|
|
masked_lm_loss = loss_fct(prediction_scores.view(-1, self.config.vocab_size), labels.view(-1))
|
|
|
|
if not return_dict:
|
|
output = (prediction_scores,) + outputs[1:]
|
|
return ((masked_lm_loss,) + output) if masked_lm_loss is not None else output
|
|
|
|
return MaskedLMOutput(
|
|
loss=masked_lm_loss,
|
|
logits=prediction_scores,
|
|
hidden_states=outputs.hidden_states,
|
|
attentions=outputs.attentions,
|
|
)
|
|
|
|
|
|
class DebertaPredictionHeadTransform(nn.Module):
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.embedding_size = getattr(config, "embedding_size", config.hidden_size)
|
|
|
|
self.dense = nn.Linear(config.hidden_size, self.embedding_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 = nn.LayerNorm(self.embedding_size, eps=config.layer_norm_eps)
|
|
|
|
def forward(self, hidden_states):
|
|
hidden_states = self.dense(hidden_states)
|
|
hidden_states = self.transform_act_fn(hidden_states)
|
|
hidden_states = self.LayerNorm(hidden_states)
|
|
return hidden_states
|
|
|
|
|
|
class DebertaLMPredictionHead(nn.Module):
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.transform = DebertaPredictionHeadTransform(config)
|
|
|
|
self.embedding_size = getattr(config, "embedding_size", config.hidden_size)
|
|
# The output weights are the same as the input embeddings, but there is
|
|
# an output-only bias for each token.
|
|
self.decoder = nn.Linear(self.embedding_size, config.vocab_size, bias=False)
|
|
|
|
self.bias = nn.Parameter(torch.zeros(config.vocab_size))
|
|
|
|
# Need a link between the two variables so that the bias is correctly resized with `resize_token_embeddings`
|
|
self.decoder.bias = self.bias
|
|
|
|
def forward(self, hidden_states):
|
|
hidden_states = self.transform(hidden_states)
|
|
hidden_states = self.decoder(hidden_states)
|
|
return hidden_states
|
|
|
|
|
|
# copied from transformers.models.bert.BertOnlyMLMHead with bert -> deberta
|
|
class DebertaOnlyMLMHead(nn.Module):
|
|
def __init__(self, config):
|
|
super().__init__()
|
|
self.predictions = DebertaLMPredictionHead(config)
|
|
|
|
def forward(self, sequence_output):
|
|
prediction_scores = self.predictions(sequence_output)
|
|
return prediction_scores
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""
|
|
DeBERTa Model transformer with a sequence classification/regression head on top (a linear layer on top of the
|
|
pooled output) e.g. for GLUE tasks.
|
|
""",
|
|
DEBERTA_START_DOCSTRING,
|
|
)
|
|
class DebertaForSequenceClassification(DebertaPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
|
|
num_labels = getattr(config, "num_labels", 2)
|
|
self.num_labels = num_labels
|
|
|
|
self.deberta = DebertaModel(config)
|
|
self.pooler = ContextPooler(config)
|
|
output_dim = self.pooler.output_dim
|
|
|
|
self.classifier = nn.Linear(output_dim, num_labels)
|
|
drop_out = getattr(config, "cls_dropout", None)
|
|
drop_out = self.config.hidden_dropout_prob if drop_out is None else drop_out
|
|
self.dropout = StableDropout(drop_out)
|
|
|
|
# Initialize weights and apply final processing
|
|
self.post_init()
|
|
|
|
def get_input_embeddings(self):
|
|
return self.deberta.get_input_embeddings()
|
|
|
|
def set_input_embeddings(self, new_embeddings):
|
|
self.deberta.set_input_embeddings(new_embeddings)
|
|
|
|
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
|
|
@add_code_sample_docstrings(
|
|
checkpoint=_CHECKPOINT_FOR_DOC,
|
|
output_type=SequenceClassifierOutput,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
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,
|
|
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, SequenceClassifierOutput]:
|
|
r"""
|
|
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.deberta(
|
|
input_ids,
|
|
token_type_ids=token_type_ids,
|
|
attention_mask=attention_mask,
|
|
position_ids=position_ids,
|
|
inputs_embeds=inputs_embeds,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
encoder_layer = outputs[0]
|
|
pooled_output = self.pooler(encoder_layer)
|
|
pooled_output = self.dropout(pooled_output)
|
|
logits = self.classifier(pooled_output)
|
|
|
|
loss = None
|
|
if labels is not None:
|
|
if self.config.problem_type is None:
|
|
if self.num_labels == 1:
|
|
# regression task
|
|
loss_fn = nn.MSELoss()
|
|
logits = logits.view(-1).to(labels.dtype)
|
|
loss = loss_fn(logits, labels.view(-1))
|
|
elif labels.dim() == 1 or labels.size(-1) == 1:
|
|
label_index = (labels >= 0).nonzero()
|
|
labels = labels.long()
|
|
if label_index.size(0) > 0:
|
|
labeled_logits = torch.gather(
|
|
logits, 0, label_index.expand(label_index.size(0), logits.size(1))
|
|
)
|
|
labels = torch.gather(labels, 0, label_index.view(-1))
|
|
loss_fct = CrossEntropyLoss()
|
|
loss = loss_fct(labeled_logits.view(-1, self.num_labels).float(), labels.view(-1))
|
|
else:
|
|
loss = torch.tensor(0).to(logits)
|
|
else:
|
|
log_softmax = nn.LogSoftmax(-1)
|
|
loss = -((log_softmax(logits) * labels).sum(-1)).mean()
|
|
elif self.config.problem_type == "regression":
|
|
loss_fct = 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 = CrossEntropyLoss()
|
|
loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
|
|
elif self.config.problem_type == "multi_label_classification":
|
|
loss_fct = BCEWithLogitsLoss()
|
|
loss = loss_fct(logits, labels)
|
|
if not return_dict:
|
|
output = (logits,) + outputs[1:]
|
|
return ((loss,) + output) if loss is not None else output
|
|
|
|
return SequenceClassifierOutput(
|
|
loss=loss, logits=logits, hidden_states=outputs.hidden_states, attentions=outputs.attentions
|
|
)
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""
|
|
DeBERTa Model with a token classification head on top (a linear layer on top of the hidden-states output) e.g. for
|
|
Named-Entity-Recognition (NER) tasks.
|
|
""",
|
|
DEBERTA_START_DOCSTRING,
|
|
)
|
|
class DebertaForTokenClassification(DebertaPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.num_labels = config.num_labels
|
|
|
|
self.deberta = DebertaModel(config)
|
|
self.dropout = nn.Dropout(config.hidden_dropout_prob)
|
|
self.classifier = nn.Linear(config.hidden_size, config.num_labels)
|
|
|
|
# Initialize weights and apply final processing
|
|
self.post_init()
|
|
|
|
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
|
|
@add_code_sample_docstrings(
|
|
checkpoint=_CHECKPOINT_FOR_DOC,
|
|
output_type=TokenClassifierOutput,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
)
|
|
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,
|
|
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, TokenClassifierOutput]:
|
|
r"""
|
|
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
|
|
Labels for computing the token classification loss. Indices should be in `[0, ..., config.num_labels - 1]`.
|
|
"""
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
outputs = self.deberta(
|
|
input_ids,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
inputs_embeds=inputs_embeds,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
sequence_output = outputs[0]
|
|
|
|
sequence_output = self.dropout(sequence_output)
|
|
logits = self.classifier(sequence_output)
|
|
|
|
loss = None
|
|
if labels is not None:
|
|
loss_fct = CrossEntropyLoss()
|
|
loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
|
|
|
|
if not return_dict:
|
|
output = (logits,) + outputs[1:]
|
|
return ((loss,) + output) if loss is not None else output
|
|
|
|
return TokenClassifierOutput(
|
|
loss=loss, logits=logits, hidden_states=outputs.hidden_states, attentions=outputs.attentions
|
|
)
|
|
|
|
|
|
@add_start_docstrings(
|
|
"""
|
|
DeBERTa Model with a span classification head on top for extractive question-answering tasks like SQuAD (a linear
|
|
layers on top of the hidden-states output to compute `span start logits` and `span end logits`).
|
|
""",
|
|
DEBERTA_START_DOCSTRING,
|
|
)
|
|
class DebertaForQuestionAnswering(DebertaPreTrainedModel):
|
|
def __init__(self, config):
|
|
super().__init__(config)
|
|
self.num_labels = config.num_labels
|
|
|
|
self.deberta = DebertaModel(config)
|
|
self.qa_outputs = nn.Linear(config.hidden_size, config.num_labels)
|
|
|
|
# Initialize weights and apply final processing
|
|
self.post_init()
|
|
|
|
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
|
|
@add_code_sample_docstrings(
|
|
checkpoint=_CHECKPOINT_FOR_QA,
|
|
output_type=QuestionAnsweringModelOutput,
|
|
config_class=_CONFIG_FOR_DOC,
|
|
expected_output=_QA_EXPECTED_OUTPUT,
|
|
expected_loss=_QA_EXPECTED_LOSS,
|
|
qa_target_start_index=_QA_TARGET_START_INDEX,
|
|
qa_target_end_index=_QA_TARGET_END_INDEX,
|
|
)
|
|
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,
|
|
inputs_embeds: Optional[torch.Tensor] = None,
|
|
start_positions: Optional[torch.Tensor] = None,
|
|
end_positions: Optional[torch.Tensor] = None,
|
|
output_attentions: Optional[bool] = None,
|
|
output_hidden_states: Optional[bool] = None,
|
|
return_dict: Optional[bool] = None,
|
|
) -> Union[Tuple, QuestionAnsweringModelOutput]:
|
|
r"""
|
|
start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
|
|
Labels for position (index) of the start of the labelled span for computing the token classification loss.
|
|
Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence
|
|
are not taken into account for computing the loss.
|
|
end_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
|
|
Labels for position (index) of the end of the labelled span for computing the token classification loss.
|
|
Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence
|
|
are not taken into account for computing the loss.
|
|
"""
|
|
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
|
|
|
|
outputs = self.deberta(
|
|
input_ids,
|
|
attention_mask=attention_mask,
|
|
token_type_ids=token_type_ids,
|
|
position_ids=position_ids,
|
|
inputs_embeds=inputs_embeds,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
sequence_output = outputs[0]
|
|
|
|
logits = self.qa_outputs(sequence_output)
|
|
start_logits, end_logits = logits.split(1, dim=-1)
|
|
start_logits = start_logits.squeeze(-1).contiguous()
|
|
end_logits = end_logits.squeeze(-1).contiguous()
|
|
|
|
total_loss = None
|
|
if start_positions is not None and end_positions is not None:
|
|
# If we are on multi-GPU, split add a dimension
|
|
if len(start_positions.size()) > 1:
|
|
start_positions = start_positions.squeeze(-1)
|
|
if len(end_positions.size()) > 1:
|
|
end_positions = end_positions.squeeze(-1)
|
|
# sometimes the start/end positions are outside our model inputs, we ignore these terms
|
|
ignored_index = start_logits.size(1)
|
|
start_positions = start_positions.clamp(0, ignored_index)
|
|
end_positions = end_positions.clamp(0, ignored_index)
|
|
|
|
loss_fct = CrossEntropyLoss(ignore_index=ignored_index)
|
|
start_loss = loss_fct(start_logits, start_positions)
|
|
end_loss = loss_fct(end_logits, end_positions)
|
|
total_loss = (start_loss + end_loss) / 2
|
|
|
|
if not return_dict:
|
|
output = (start_logits, end_logits) + outputs[1:]
|
|
return ((total_loss,) + output) if total_loss is not None else output
|
|
|
|
return QuestionAnsweringModelOutput(
|
|
loss=total_loss,
|
|
start_logits=start_logits,
|
|
end_logits=end_logits,
|
|
hidden_states=outputs.hidden_states,
|
|
attentions=outputs.attentions,
|
|
)
|