winnie22 / transformers_4_35_0 /models /deberta /modeling_tf_deberta.py
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# coding=utf-8
# Copyright 2021 Microsoft and The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
""" TF 2.0 DeBERTa model."""
from __future__ import annotations
import math
from typing import Dict, Optional, Sequence, Tuple, Union
import numpy as np
import tensorflow as tf
from ...activations_tf import get_tf_activation
from ...modeling_tf_outputs import (
TFBaseModelOutput,
TFMaskedLMOutput,
TFQuestionAnsweringModelOutput,
TFSequenceClassifierOutput,
TFTokenClassifierOutput,
)
from ...modeling_tf_utils import (
TFMaskedLanguageModelingLoss,
TFModelInputType,
TFPreTrainedModel,
TFQuestionAnsweringLoss,
TFSequenceClassificationLoss,
TFTokenClassificationLoss,
get_initializer,
unpack_inputs,
)
from ...tf_utils import check_embeddings_within_bounds, shape_list, stable_softmax
from ...utils import add_code_sample_docstrings, add_start_docstrings, add_start_docstrings_to_model_forward, logging
from .configuration_deberta import DebertaConfig
logger = logging.get_logger(__name__)
_CONFIG_FOR_DOC = "DebertaConfig"
_CHECKPOINT_FOR_DOC = "kamalkraj/deberta-base"
TF_DEBERTA_PRETRAINED_MODEL_ARCHIVE_LIST = [
"kamalkraj/deberta-base",
# See all DeBERTa models at https://huggingface.co/models?filter=DeBERTa
]
class TFDebertaContextPooler(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(config.pooler_hidden_size, name="dense")
self.dropout = TFDebertaStableDropout(config.pooler_dropout, name="dropout")
self.config = config
def call(self, hidden_states, training: bool = False):
# We "pool" the model by simply taking the hidden state corresponding
# to the first token.
context_token = hidden_states[:, 0]
context_token = self.dropout(context_token, training=training)
pooled_output = self.dense(context_token)
pooled_output = get_tf_activation(self.config.pooler_hidden_act)(pooled_output)
return pooled_output
@property
def output_dim(self) -> int:
return self.config.hidden_size
class TFDebertaXSoftmax(tf.keras.layers.Layer):
"""
Masked Softmax which is optimized for saving memory
Args:
input (`tf.Tensor`): The input tensor that will apply softmax.
mask (`tf.Tensor`): The mask matrix where 0 indicate that element will be ignored in the softmax calculation.
dim (int): The dimension that will apply softmax
"""
def __init__(self, axis=-1, **kwargs):
super().__init__(**kwargs)
self.axis = axis
def call(self, inputs: tf.Tensor, mask: tf.Tensor):
rmask = tf.logical_not(tf.cast(mask, tf.bool))
output = tf.where(rmask, float("-inf"), inputs)
output = stable_softmax(output, self.axis)
output = tf.where(rmask, 0.0, output)
return output
class TFDebertaStableDropout(tf.keras.layers.Layer):
"""
Optimized dropout module for stabilizing the training
Args:
drop_prob (float): the dropout probabilities
"""
def __init__(self, drop_prob, **kwargs):
super().__init__(**kwargs)
self.drop_prob = drop_prob
@tf.custom_gradient
def xdropout(self, inputs):
"""
Applies dropout to the inputs, as vanilla dropout, but also scales the remaining elements up by 1/drop_prob.
"""
mask = tf.cast(
1
- tf.compat.v1.distributions.Bernoulli(probs=1.0 - self.drop_prob).sample(sample_shape=shape_list(inputs)),
tf.bool,
)
scale = tf.convert_to_tensor(1.0 / (1 - self.drop_prob), dtype=tf.float32)
if self.drop_prob > 0:
inputs = tf.where(mask, 0.0, inputs) * scale
def grad(upstream):
if self.drop_prob > 0:
return tf.where(mask, 0.0, upstream) * scale
else:
return upstream
return inputs, grad
def call(self, inputs: tf.Tensor, training: tf.Tensor = False):
if training:
return self.xdropout(inputs)
return inputs
class TFDebertaLayerNorm(tf.keras.layers.Layer):
"""LayerNorm module in the TF style (epsilon inside the square root)."""
def __init__(self, size, eps=1e-12, **kwargs):
super().__init__(**kwargs)
self.size = size
self.eps = eps
def build(self, input_shape):
self.gamma = self.add_weight(shape=[self.size], initializer=tf.ones_initializer(), name="weight")
self.beta = self.add_weight(shape=[self.size], initializer=tf.zeros_initializer(), name="bias")
return super().build(input_shape)
def call(self, x: tf.Tensor) -> tf.Tensor:
mean = tf.reduce_mean(x, axis=[-1], keepdims=True)
variance = tf.reduce_mean(tf.square(x - mean), axis=[-1], keepdims=True)
std = tf.math.sqrt(variance + self.eps)
return self.gamma * (x - mean) / std + self.beta
class TFDebertaSelfOutput(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(config.hidden_size, name="dense")
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
self.dropout = TFDebertaStableDropout(config.hidden_dropout_prob, name="dropout")
def call(self, hidden_states, input_tensor, training: bool = False):
hidden_states = self.dense(hidden_states)
hidden_states = self.dropout(hidden_states, training=training)
hidden_states = self.LayerNorm(hidden_states + input_tensor)
return hidden_states
class TFDebertaAttention(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.self = TFDebertaDisentangledSelfAttention(config, name="self")
self.dense_output = TFDebertaSelfOutput(config, name="output")
self.config = config
def call(
self,
input_tensor: tf.Tensor,
attention_mask: tf.Tensor,
query_states: tf.Tensor = None,
relative_pos: tf.Tensor = None,
rel_embeddings: tf.Tensor = None,
output_attentions: bool = False,
training: bool = False,
) -> Tuple[tf.Tensor]:
self_outputs = self.self(
hidden_states=input_tensor,
attention_mask=attention_mask,
query_states=query_states,
relative_pos=relative_pos,
rel_embeddings=rel_embeddings,
output_attentions=output_attentions,
training=training,
)
if query_states is None:
query_states = input_tensor
attention_output = self.dense_output(
hidden_states=self_outputs[0], input_tensor=query_states, training=training
)
output = (attention_output,) + self_outputs[1:]
return output
class TFDebertaIntermediate(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
units=config.intermediate_size, kernel_initializer=get_initializer(config.initializer_range), name="dense"
)
if isinstance(config.hidden_act, str):
self.intermediate_act_fn = get_tf_activation(config.hidden_act)
else:
self.intermediate_act_fn = config.hidden_act
def call(self, hidden_states: tf.Tensor) -> tf.Tensor:
hidden_states = self.dense(inputs=hidden_states)
hidden_states = self.intermediate_act_fn(hidden_states)
return hidden_states
class TFDebertaOutput(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
units=config.hidden_size, kernel_initializer=get_initializer(config.initializer_range), name="dense"
)
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
self.dropout = TFDebertaStableDropout(config.hidden_dropout_prob, name="dropout")
def call(self, hidden_states: tf.Tensor, input_tensor: tf.Tensor, training: bool = False) -> tf.Tensor:
hidden_states = self.dense(inputs=hidden_states)
hidden_states = self.dropout(hidden_states, training=training)
hidden_states = self.LayerNorm(hidden_states + input_tensor)
return hidden_states
class TFDebertaLayer(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.attention = TFDebertaAttention(config, name="attention")
self.intermediate = TFDebertaIntermediate(config, name="intermediate")
self.bert_output = TFDebertaOutput(config, name="output")
def call(
self,
hidden_states: tf.Tensor,
attention_mask: tf.Tensor,
query_states: tf.Tensor = None,
relative_pos: tf.Tensor = None,
rel_embeddings: tf.Tensor = None,
output_attentions: bool = False,
training: bool = False,
) -> Tuple[tf.Tensor]:
attention_outputs = self.attention(
input_tensor=hidden_states,
attention_mask=attention_mask,
query_states=query_states,
relative_pos=relative_pos,
rel_embeddings=rel_embeddings,
output_attentions=output_attentions,
training=training,
)
attention_output = attention_outputs[0]
intermediate_output = self.intermediate(hidden_states=attention_output)
layer_output = self.bert_output(
hidden_states=intermediate_output, input_tensor=attention_output, training=training
)
outputs = (layer_output,) + attention_outputs[1:] # add attentions if we output them
return outputs
class TFDebertaEncoder(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.layer = [TFDebertaLayer(config, name=f"layer_._{i}") for i in range(config.num_hidden_layers)]
self.relative_attention = getattr(config, "relative_attention", False)
self.config = config
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
def build(self, input_shape):
if self.relative_attention:
self.rel_embeddings = self.add_weight(
name="rel_embeddings.weight",
shape=[self.max_relative_positions * 2, self.config.hidden_size],
initializer=get_initializer(self.config.initializer_range),
)
return super().build(input_shape)
def get_rel_embedding(self):
rel_embeddings = self.rel_embeddings if self.relative_attention else None
return rel_embeddings
def get_attention_mask(self, attention_mask):
if len(shape_list(attention_mask)) <= 2:
extended_attention_mask = tf.expand_dims(tf.expand_dims(attention_mask, 1), 2)
attention_mask = extended_attention_mask * tf.expand_dims(tf.squeeze(extended_attention_mask, -2), -1)
attention_mask = tf.cast(attention_mask, tf.uint8)
elif len(shape_list(attention_mask)) == 3:
attention_mask = tf.expand_dims(attention_mask, 1)
return attention_mask
def get_rel_pos(self, hidden_states, query_states=None, relative_pos=None):
if self.relative_attention and relative_pos is None:
q = shape_list(query_states)[-2] if query_states is not None else shape_list(hidden_states)[-2]
relative_pos = build_relative_position(q, shape_list(hidden_states)[-2])
return relative_pos
def call(
self,
hidden_states: tf.Tensor,
attention_mask: tf.Tensor,
query_states: tf.Tensor = None,
relative_pos: tf.Tensor = None,
output_attentions: bool = False,
output_hidden_states: bool = False,
return_dict: bool = True,
training: bool = False,
) -> Union[TFBaseModelOutput, Tuple[tf.Tensor]]:
all_hidden_states = () if output_hidden_states else None
all_attentions = () if output_attentions else None
attention_mask = self.get_attention_mask(attention_mask)
relative_pos = self.get_rel_pos(hidden_states, query_states, relative_pos)
if isinstance(hidden_states, Sequence):
next_kv = hidden_states[0]
else:
next_kv = hidden_states
rel_embeddings = self.get_rel_embedding()
for i, layer_module in enumerate(self.layer):
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
layer_outputs = layer_module(
hidden_states=next_kv,
attention_mask=attention_mask,
query_states=query_states,
relative_pos=relative_pos,
rel_embeddings=rel_embeddings,
output_attentions=output_attentions,
training=training,
)
hidden_states = layer_outputs[0]
if query_states is not None:
query_states = hidden_states
if isinstance(hidden_states, Sequence):
next_kv = hidden_states[i + 1] if i + 1 < len(self.layer) else None
else:
next_kv = hidden_states
if output_attentions:
all_attentions = all_attentions + (layer_outputs[1],)
# Add last layer
if output_hidden_states:
all_hidden_states = all_hidden_states + (hidden_states,)
if not return_dict:
return tuple(v for v in [hidden_states, all_hidden_states, all_attentions] if v is not None)
return TFBaseModelOutput(
last_hidden_state=hidden_states, hidden_states=all_hidden_states, attentions=all_attentions
)
def build_relative_position(query_size, key_size):
"""
Build relative position according to the query and key
We assume the absolute position of query \\(P_q\\) is range from (0, query_size) and the absolute position of key
\\(P_k\\) is range from (0, key_size), The relative positions from query to key is \\(R_{q \\rightarrow k} = P_q -
P_k\\)
Args:
query_size (int): the length of query
key_size (int): the length of key
Return:
`tf.Tensor`: A tensor with shape [1, query_size, key_size]
"""
q_ids = tf.range(query_size, dtype=tf.int32)
k_ids = tf.range(key_size, dtype=tf.int32)
rel_pos_ids = q_ids[:, None] - tf.tile(tf.reshape(k_ids, [1, -1]), [query_size, 1])
rel_pos_ids = rel_pos_ids[:query_size, :]
rel_pos_ids = tf.expand_dims(rel_pos_ids, axis=0)
return tf.cast(rel_pos_ids, tf.int64)
def c2p_dynamic_expand(c2p_pos, query_layer, relative_pos):
shapes = [
shape_list(query_layer)[0],
shape_list(query_layer)[1],
shape_list(query_layer)[2],
shape_list(relative_pos)[-1],
]
return tf.broadcast_to(c2p_pos, shapes)
def p2c_dynamic_expand(c2p_pos, query_layer, key_layer):
shapes = [
shape_list(query_layer)[0],
shape_list(query_layer)[1],
shape_list(key_layer)[-2],
shape_list(key_layer)[-2],
]
return tf.broadcast_to(c2p_pos, shapes)
def pos_dynamic_expand(pos_index, p2c_att, key_layer):
shapes = shape_list(p2c_att)[:2] + [shape_list(pos_index)[-2], shape_list(key_layer)[-2]]
return tf.broadcast_to(pos_index, shapes)
def torch_gather(x, indices, gather_axis):
if gather_axis < 0:
gather_axis = tf.rank(x) + gather_axis
if gather_axis != tf.rank(x) - 1:
pre_roll = tf.rank(x) - 1 - gather_axis
permutation = tf.roll(tf.range(tf.rank(x)), pre_roll, axis=0)
x = tf.transpose(x, perm=permutation)
indices = tf.transpose(indices, perm=permutation)
else:
pre_roll = 0
flat_x = tf.reshape(x, (-1, tf.shape(x)[-1]))
flat_indices = tf.reshape(indices, (-1, tf.shape(indices)[-1]))
gathered = tf.gather(flat_x, flat_indices, batch_dims=1)
gathered = tf.reshape(gathered, tf.shape(indices))
if pre_roll != 0:
permutation = tf.roll(tf.range(tf.rank(x)), -pre_roll, axis=0)
gathered = tf.transpose(gathered, perm=permutation)
return gathered
class TFDebertaDisentangledSelfAttention(tf.keras.layers.Layer):
"""
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: DebertaConfig, **kwargs):
super().__init__(**kwargs)
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 = tf.keras.layers.Dense(
self.all_head_size * 3,
kernel_initializer=get_initializer(config.initializer_range),
name="in_proj",
use_bias=False,
)
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 = tf.keras.layers.Dense(
self.num_attention_heads,
kernel_initializer=get_initializer(config.initializer_range),
name="head_logits_proj",
use_bias=False,
)
self.head_weights_proj = tf.keras.layers.Dense(
self.num_attention_heads,
kernel_initializer=get_initializer(config.initializer_range),
name="head_weights_proj",
use_bias=False,
)
self.softmax = TFDebertaXSoftmax(axis=-1)
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 = TFDebertaStableDropout(config.hidden_dropout_prob, name="pos_dropout")
if "c2p" in self.pos_att_type:
self.pos_proj = tf.keras.layers.Dense(
self.all_head_size,
kernel_initializer=get_initializer(config.initializer_range),
name="pos_proj",
use_bias=False,
)
if "p2c" in self.pos_att_type:
self.pos_q_proj = tf.keras.layers.Dense(
self.all_head_size, kernel_initializer=get_initializer(config.initializer_range), name="pos_q_proj"
)
self.dropout = TFDebertaStableDropout(config.attention_probs_dropout_prob, name="dropout")
def build(self, input_shape):
self.q_bias = self.add_weight(
name="q_bias", shape=(self.all_head_size), initializer=tf.keras.initializers.Zeros()
)
self.v_bias = self.add_weight(
name="v_bias", shape=(self.all_head_size), initializer=tf.keras.initializers.Zeros()
)
return super().build(input_shape)
def transpose_for_scores(self, tensor: tf.Tensor) -> tf.Tensor:
shape = shape_list(tensor)[:-1] + [self.num_attention_heads, -1]
# Reshape from [batch_size, seq_length, all_head_size] to [batch_size, seq_length, num_attention_heads, attention_head_size]
tensor = tf.reshape(tensor=tensor, shape=shape)
# Transpose the tensor from [batch_size, seq_length, num_attention_heads, attention_head_size] to [batch_size, num_attention_heads, seq_length, attention_head_size]
return tf.transpose(tensor, perm=[0, 2, 1, 3])
def call(
self,
hidden_states: tf.Tensor,
attention_mask: tf.Tensor,
query_states: tf.Tensor = None,
relative_pos: tf.Tensor = None,
rel_embeddings: tf.Tensor = None,
output_attentions: bool = False,
training: bool = False,
) -> Tuple[tf.Tensor]:
"""
Call the module
Args:
hidden_states (`tf.Tensor`):
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 (`tf.Tensor`):
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.
return_att (`bool`, optional):
Whether return the attention matrix.
query_states (`tf.Tensor`, optional):
The *Q* state in *Attention(Q,K,V)*.
relative_pos (`tf.Tensor`):
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 (`tf.Tensor`):
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 = tf.split(
self.transpose_for_scores(qp), num_or_size_splits=3, axis=-1
)
else:
def linear(w, b, x):
out = tf.matmul(x, w, transpose_b=True)
if b is not None:
out += tf.transpose(b)
return out
ws = tf.split(
tf.transpose(self.in_proj.weight[0]), num_or_size_splits=self.num_attention_heads * 3, axis=0
)
qkvw = tf.TensorArray(dtype=tf.float32, size=3)
for k in tf.range(3):
qkvw_inside = tf.TensorArray(dtype=tf.float32, size=self.num_attention_heads)
for i in tf.range(self.num_attention_heads):
qkvw_inside = qkvw_inside.write(i, ws[i * 3 + k])
qkvw = qkvw.write(k, qkvw_inside.concat())
qkvb = [None] * 3
q = linear(qkvw[0], qkvb[0], query_states)
k = linear(qkvw[1], qkvb[1], hidden_states)
v = linear(qkvw[2], qkvb[2], hidden_states)
query_layer = self.transpose_for_scores(q)
key_layer = self.transpose_for_scores(k)
value_layer = self.transpose_for_scores(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 = math.sqrt(shape_list(query_layer)[-1] * scale_factor)
query_layer = query_layer / scale
attention_scores = tf.matmul(query_layer, tf.transpose(key_layer, [0, 1, 3, 2]))
if self.relative_attention:
rel_embeddings = self.pos_dropout(rel_embeddings, training=training)
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
if self.talking_head:
attention_scores = tf.transpose(
self.head_logits_proj(tf.transpose(attention_scores, [0, 2, 3, 1])), [0, 3, 1, 2]
)
attention_probs = self.softmax(attention_scores, attention_mask)
attention_probs = self.dropout(attention_probs, training=training)
if self.talking_head:
attention_probs = tf.transpose(
self.head_weights_proj(tf.transpose(attention_probs, [0, 2, 3, 1])), [0, 3, 1, 2]
)
context_layer = tf.matmul(attention_probs, value_layer)
context_layer = tf.transpose(context_layer, [0, 2, 1, 3])
context_layer_shape = shape_list(context_layer)
# Set the final dimension here explicitly.
# Calling tf.reshape(context_layer, (*context_layer_shape[:-2], -1)) raises an error when executing
# the model in graph mode as context_layer is reshaped to (None, 7, None) and Dense layer in TFDebertaV2SelfOutput
# requires final input dimension to be defined
new_context_layer_shape = context_layer_shape[:-2] + [context_layer_shape[-2] * context_layer_shape[-1]]
context_layer = tf.reshape(context_layer, new_context_layer_shape)
outputs = (context_layer, attention_probs) if output_attentions else (context_layer,)
return outputs
def disentangled_att_bias(self, query_layer, key_layer, relative_pos, rel_embeddings, scale_factor):
if relative_pos is None:
q = shape_list(query_layer)[-2]
relative_pos = build_relative_position(q, shape_list(key_layer)[-2])
shape_list_pos = shape_list(relative_pos)
if len(shape_list_pos) == 2:
relative_pos = tf.expand_dims(tf.expand_dims(relative_pos, 0), 0)
elif len(shape_list_pos) == 3:
relative_pos = tf.expand_dims(relative_pos, 1)
# bxhxqxk
elif len(shape_list_pos) != 4:
raise ValueError(f"Relative position ids must be of dim 2 or 3 or 4. {len(shape_list_pos)}")
att_span = tf.cast(
tf.minimum(
tf.maximum(shape_list(query_layer)[-2], shape_list(key_layer)[-2]), self.max_relative_positions
),
tf.int64,
)
rel_embeddings = tf.expand_dims(
rel_embeddings[self.max_relative_positions - att_span : self.max_relative_positions + att_span, :], 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 = tf.matmul(query_layer, tf.transpose(pos_key_layer, [0, 1, 3, 2]))
c2p_pos = tf.clip_by_value(relative_pos + att_span, 0, att_span * 2 - 1)
c2p_att = torch_gather(c2p_att, c2p_dynamic_expand(c2p_pos, query_layer, relative_pos), -1)
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 /= tf.math.sqrt(tf.cast(shape_list(pos_query_layer)[-1] * scale_factor, dtype=tf.float32))
if shape_list(query_layer)[-2] != shape_list(key_layer)[-2]:
r_pos = build_relative_position(shape_list(key_layer)[-2], shape_list(key_layer)[-2])
else:
r_pos = relative_pos
p2c_pos = tf.clip_by_value(-r_pos + att_span, 0, att_span * 2 - 1)
p2c_att = tf.matmul(key_layer, tf.transpose(pos_query_layer, [0, 1, 3, 2]))
p2c_att = tf.transpose(
torch_gather(p2c_att, p2c_dynamic_expand(p2c_pos, query_layer, key_layer), -1), [0, 1, 3, 2]
)
if shape_list(query_layer)[-2] != shape_list(key_layer)[-2]:
pos_index = tf.expand_dims(relative_pos[:, :, :, 0], -1)
p2c_att = torch_gather(p2c_att, pos_dynamic_expand(pos_index, p2c_att, key_layer), -2)
score += p2c_att
return score
class TFDebertaEmbeddings(tf.keras.layers.Layer):
"""Construct the embeddings from word, position and token_type embeddings."""
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.config = config
self.embedding_size = getattr(config, "embedding_size", config.hidden_size)
self.hidden_size = config.hidden_size
self.max_position_embeddings = config.max_position_embeddings
self.position_biased_input = getattr(config, "position_biased_input", True)
self.initializer_range = config.initializer_range
if self.embedding_size != config.hidden_size:
self.embed_proj = tf.keras.layers.Dense(
config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
name="embed_proj",
use_bias=False,
)
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
self.dropout = TFDebertaStableDropout(config.hidden_dropout_prob, name="dropout")
def build(self, input_shape: tf.TensorShape):
with tf.name_scope("word_embeddings"):
self.weight = self.add_weight(
name="weight",
shape=[self.config.vocab_size, self.embedding_size],
initializer=get_initializer(self.initializer_range),
)
with tf.name_scope("token_type_embeddings"):
if self.config.type_vocab_size > 0:
self.token_type_embeddings = self.add_weight(
name="embeddings",
shape=[self.config.type_vocab_size, self.embedding_size],
initializer=get_initializer(self.initializer_range),
)
else:
self.token_type_embeddings = None
with tf.name_scope("position_embeddings"):
if self.position_biased_input:
self.position_embeddings = self.add_weight(
name="embeddings",
shape=[self.max_position_embeddings, self.hidden_size],
initializer=get_initializer(self.initializer_range),
)
else:
self.position_embeddings = None
super().build(input_shape)
def call(
self,
input_ids: tf.Tensor = None,
position_ids: tf.Tensor = None,
token_type_ids: tf.Tensor = None,
inputs_embeds: tf.Tensor = None,
mask: tf.Tensor = None,
training: bool = False,
) -> tf.Tensor:
"""
Applies embedding based on inputs tensor.
Returns:
final_embeddings (`tf.Tensor`): output embedding tensor.
"""
if input_ids is None and inputs_embeds is None:
raise ValueError("Need to provide either `input_ids` or `input_embeds`.")
if input_ids is not None:
check_embeddings_within_bounds(input_ids, self.config.vocab_size)
inputs_embeds = tf.gather(params=self.weight, indices=input_ids)
input_shape = shape_list(inputs_embeds)[:-1]
if token_type_ids is None:
token_type_ids = tf.fill(dims=input_shape, value=0)
if position_ids is None:
position_ids = tf.expand_dims(tf.range(start=0, limit=input_shape[-1]), axis=0)
final_embeddings = inputs_embeds
if self.position_biased_input:
position_embeds = tf.gather(params=self.position_embeddings, indices=position_ids)
final_embeddings += position_embeds
if self.config.type_vocab_size > 0:
token_type_embeds = tf.gather(params=self.token_type_embeddings, indices=token_type_ids)
final_embeddings += token_type_embeds
if self.embedding_size != self.hidden_size:
final_embeddings = self.embed_proj(final_embeddings)
final_embeddings = self.LayerNorm(final_embeddings)
if mask is not None:
if len(shape_list(mask)) != len(shape_list(final_embeddings)):
if len(shape_list(mask)) == 4:
mask = tf.squeeze(tf.squeeze(mask, axis=1), axis=1)
mask = tf.cast(tf.expand_dims(mask, axis=2), tf.float32)
final_embeddings = final_embeddings * mask
final_embeddings = self.dropout(final_embeddings, training=training)
return final_embeddings
class TFDebertaPredictionHeadTransform(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.embedding_size = getattr(config, "embedding_size", config.hidden_size)
self.dense = tf.keras.layers.Dense(
units=self.embedding_size,
kernel_initializer=get_initializer(config.initializer_range),
name="dense",
)
if isinstance(config.hidden_act, str):
self.transform_act_fn = get_tf_activation(config.hidden_act)
else:
self.transform_act_fn = config.hidden_act
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
def call(self, hidden_states: tf.Tensor) -> tf.Tensor:
hidden_states = self.dense(inputs=hidden_states)
hidden_states = self.transform_act_fn(hidden_states)
hidden_states = self.LayerNorm(hidden_states)
return hidden_states
class TFDebertaLMPredictionHead(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, input_embeddings: tf.keras.layers.Layer, **kwargs):
super().__init__(**kwargs)
self.config = config
self.embedding_size = getattr(config, "embedding_size", config.hidden_size)
self.transform = TFDebertaPredictionHeadTransform(config, name="transform")
# The output weights are the same as the input embeddings, but there is
# an output-only bias for each token.
self.input_embeddings = input_embeddings
def build(self, input_shape: tf.TensorShape):
self.bias = self.add_weight(shape=(self.config.vocab_size,), initializer="zeros", trainable=True, name="bias")
super().build(input_shape)
def get_output_embeddings(self) -> tf.keras.layers.Layer:
return self.input_embeddings
def set_output_embeddings(self, value: tf.Variable):
self.input_embeddings.weight = value
self.input_embeddings.vocab_size = shape_list(value)[0]
def get_bias(self) -> Dict[str, tf.Variable]:
return {"bias": self.bias}
def set_bias(self, value: tf.Variable):
self.bias = value["bias"]
self.config.vocab_size = shape_list(value["bias"])[0]
def call(self, hidden_states: tf.Tensor) -> tf.Tensor:
hidden_states = self.transform(hidden_states=hidden_states)
seq_length = shape_list(hidden_states)[1]
hidden_states = tf.reshape(tensor=hidden_states, shape=[-1, self.embedding_size])
hidden_states = tf.matmul(a=hidden_states, b=self.input_embeddings.weight, transpose_b=True)
hidden_states = tf.reshape(tensor=hidden_states, shape=[-1, seq_length, self.config.vocab_size])
hidden_states = tf.nn.bias_add(value=hidden_states, bias=self.bias)
return hidden_states
class TFDebertaOnlyMLMHead(tf.keras.layers.Layer):
def __init__(self, config: DebertaConfig, input_embeddings: tf.keras.layers.Layer, **kwargs):
super().__init__(**kwargs)
self.predictions = TFDebertaLMPredictionHead(config, input_embeddings, name="predictions")
def call(self, sequence_output: tf.Tensor) -> tf.Tensor:
prediction_scores = self.predictions(hidden_states=sequence_output)
return prediction_scores
# @keras_serializable
class TFDebertaMainLayer(tf.keras.layers.Layer):
config_class = DebertaConfig
def __init__(self, config: DebertaConfig, **kwargs):
super().__init__(**kwargs)
self.config = config
self.embeddings = TFDebertaEmbeddings(config, name="embeddings")
self.encoder = TFDebertaEncoder(config, name="encoder")
def get_input_embeddings(self) -> tf.keras.layers.Layer:
return self.embeddings
def set_input_embeddings(self, value: tf.Variable):
self.embeddings.weight = value
self.embeddings.vocab_size = shape_list(value)[0]
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
@unpack_inputs
def call(
self,
input_ids: TFModelInputType | None = None,
attention_mask: np.ndarray | tf.Tensor | None = None,
token_type_ids: np.ndarray | tf.Tensor | None = None,
position_ids: np.ndarray | tf.Tensor | None = None,
inputs_embeds: np.ndarray | tf.Tensor | None = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
training: bool = False,
) -> Union[TFBaseModelOutput, Tuple[tf.Tensor]]:
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 = shape_list(input_ids)
elif inputs_embeds is not None:
input_shape = shape_list(inputs_embeds)[:-1]
else:
raise ValueError("You have to specify either input_ids or inputs_embeds")
if attention_mask is None:
attention_mask = tf.fill(dims=input_shape, value=1)
if token_type_ids is None:
token_type_ids = tf.fill(dims=input_shape, value=0)
embedding_output = self.embeddings(
input_ids=input_ids,
position_ids=position_ids,
token_type_ids=token_type_ids,
inputs_embeds=inputs_embeds,
mask=attention_mask,
training=training,
)
encoder_outputs = self.encoder(
hidden_states=embedding_output,
attention_mask=attention_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
training=training,
)
sequence_output = encoder_outputs[0]
if not return_dict:
return (sequence_output,) + encoder_outputs[1:]
return TFBaseModelOutput(
last_hidden_state=sequence_output,
hidden_states=encoder_outputs.hidden_states,
attentions=encoder_outputs.attentions,
)
class TFDebertaPreTrainedModel(TFPreTrainedModel):
"""
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
models.
"""
config_class = DebertaConfig
base_model_prefix = "deberta"
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 [tf.keras.Model](https://www.tensorflow.org/api_docs/python/tf/keras/Model) subclass. Use it
as a regular TF 2.0 Keras Model and refer to the TF 2.0 documentation for all matter related to general usage and
behavior.
<Tip>
TensorFlow models and layers in `transformers` accept two formats as input:
- having all inputs as keyword arguments (like PyTorch models), or
- having all inputs as a list, tuple or dict in the first positional argument.
The reason the second format is supported is that Keras methods prefer this format when passing inputs to models
and layers. Because of this support, when using methods like `model.fit()` things should "just work" for you - just
pass your inputs and labels in any format that `model.fit()` supports! If, however, you want to use the second
format outside of Keras methods like `fit()` and `predict()`, such as when creating your own layers or models with
the Keras `Functional` API, there are three possibilities you can use to gather all the input Tensors in the first
positional argument:
- a single Tensor with `input_ids` only and nothing else: `model(input_ids)`
- a list of varying length with one or several input Tensors IN THE ORDER given in the docstring:
`model([input_ids, attention_mask])` or `model([input_ids, attention_mask, token_type_ids])`
- a dictionary with one or several input Tensors associated to the input names given in the docstring:
`model({"input_ids": input_ids, "token_type_ids": token_type_ids})`
Note that when creating models and layers with
[subclassing](https://keras.io/guides/making_new_layers_and_models_via_subclassing/) then you don't need to worry
about any of this, as you can just pass inputs like you would to any other Python function!
</Tip>
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 (`np.ndarray`, `tf.Tensor`, `List[tf.Tensor]` ``Dict[str, tf.Tensor]` or `Dict[str, np.ndarray]` and each example must have the 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 (`np.ndarray` or `tf.Tensor` 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 (`np.ndarray` or `tf.Tensor` 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 (`np.ndarray` or `tf.Tensor` 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 (`np.ndarray` or `tf.Tensor` 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 TFDebertaModel(TFDebertaPreTrainedModel):
def __init__(self, config: DebertaConfig, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.deberta = TFDebertaMainLayer(config, name="deberta")
@unpack_inputs
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@add_code_sample_docstrings(
checkpoint=_CHECKPOINT_FOR_DOC,
output_type=TFBaseModelOutput,
config_class=_CONFIG_FOR_DOC,
)
def call(
self,
input_ids: TFModelInputType | None = None,
attention_mask: np.ndarray | tf.Tensor | None = None,
token_type_ids: np.ndarray | tf.Tensor | None = None,
position_ids: np.ndarray | tf.Tensor | None = None,
inputs_embeds: np.ndarray | tf.Tensor | None = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
training: Optional[bool] = False,
) -> Union[TFBaseModelOutput, Tuple[tf.Tensor]]:
outputs = self.deberta(
input_ids=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,
training=training,
)
return outputs
@add_start_docstrings("""DeBERTa Model with a `language modeling` head on top.""", DEBERTA_START_DOCSTRING)
class TFDebertaForMaskedLM(TFDebertaPreTrainedModel, TFMaskedLanguageModelingLoss):
def __init__(self, config: DebertaConfig, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
if config.is_decoder:
logger.warning(
"If you want to use `TFDebertaForMaskedLM` make sure `config.is_decoder=False` for "
"bi-directional self-attention."
)
self.deberta = TFDebertaMainLayer(config, name="deberta")
self.mlm = TFDebertaOnlyMLMHead(config, input_embeddings=self.deberta.embeddings, name="cls")
def get_lm_head(self) -> tf.keras.layers.Layer:
return self.mlm.predictions
@unpack_inputs
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@add_code_sample_docstrings(
checkpoint=_CHECKPOINT_FOR_DOC,
output_type=TFMaskedLMOutput,
config_class=_CONFIG_FOR_DOC,
)
def call(
self,
input_ids: TFModelInputType | None = None,
attention_mask: np.ndarray | tf.Tensor | None = None,
token_type_ids: np.ndarray | tf.Tensor | None = None,
position_ids: np.ndarray | tf.Tensor | None = None,
inputs_embeds: np.ndarray | tf.Tensor | None = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
labels: np.ndarray | tf.Tensor | None = None,
training: Optional[bool] = False,
) -> Union[TFMaskedLMOutput, Tuple[tf.Tensor]]:
r"""
labels (`tf.Tensor` or `np.ndarray` 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]`
"""
outputs = self.deberta(
input_ids=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,
training=training,
)
sequence_output = outputs[0]
prediction_scores = self.mlm(sequence_output=sequence_output, training=training)
loss = None if labels is None else self.hf_compute_loss(labels=labels, logits=prediction_scores)
if not return_dict:
output = (prediction_scores,) + outputs[2:]
return ((loss,) + output) if loss is not None else output
return TFMaskedLMOutput(
loss=loss,
logits=prediction_scores,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
@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 TFDebertaForSequenceClassification(TFDebertaPreTrainedModel, TFSequenceClassificationLoss):
def __init__(self, config: DebertaConfig, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.num_labels = config.num_labels
self.deberta = TFDebertaMainLayer(config, name="deberta")
self.pooler = TFDebertaContextPooler(config, name="pooler")
drop_out = getattr(config, "cls_dropout", None)
drop_out = self.config.hidden_dropout_prob if drop_out is None else drop_out
self.dropout = TFDebertaStableDropout(drop_out, name="cls_dropout")
self.classifier = tf.keras.layers.Dense(
units=config.num_labels,
kernel_initializer=get_initializer(config.initializer_range),
name="classifier",
)
@unpack_inputs
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@add_code_sample_docstrings(
checkpoint=_CHECKPOINT_FOR_DOC,
output_type=TFSequenceClassifierOutput,
config_class=_CONFIG_FOR_DOC,
)
def call(
self,
input_ids: TFModelInputType | None = None,
attention_mask: np.ndarray | tf.Tensor | None = None,
token_type_ids: np.ndarray | tf.Tensor | None = None,
position_ids: np.ndarray | tf.Tensor | None = None,
inputs_embeds: np.ndarray | tf.Tensor | None = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
labels: np.ndarray | tf.Tensor | None = None,
training: Optional[bool] = False,
) -> Union[TFSequenceClassifierOutput, Tuple[tf.Tensor]]:
r"""
labels (`tf.Tensor` or `np.ndarray` 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).
"""
outputs = self.deberta(
input_ids=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,
training=training,
)
sequence_output = outputs[0]
pooled_output = self.pooler(sequence_output, training=training)
pooled_output = self.dropout(pooled_output, training=training)
logits = self.classifier(pooled_output)
loss = None if labels is None else self.hf_compute_loss(labels=labels, logits=logits)
if not return_dict:
output = (logits,) + outputs[1:]
return ((loss,) + output) if loss is not None else output
return TFSequenceClassifierOutput(
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 TFDebertaForTokenClassification(TFDebertaPreTrainedModel, TFTokenClassificationLoss):
def __init__(self, config: DebertaConfig, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.num_labels = config.num_labels
self.deberta = TFDebertaMainLayer(config, name="deberta")
self.dropout = tf.keras.layers.Dropout(rate=config.hidden_dropout_prob)
self.classifier = tf.keras.layers.Dense(
units=config.num_labels, kernel_initializer=get_initializer(config.initializer_range), name="classifier"
)
@unpack_inputs
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@add_code_sample_docstrings(
checkpoint=_CHECKPOINT_FOR_DOC,
output_type=TFTokenClassifierOutput,
config_class=_CONFIG_FOR_DOC,
)
def call(
self,
input_ids: TFModelInputType | None = None,
attention_mask: np.ndarray | tf.Tensor | None = None,
token_type_ids: np.ndarray | tf.Tensor | None = None,
position_ids: np.ndarray | tf.Tensor | None = None,
inputs_embeds: np.ndarray | tf.Tensor | None = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
labels: np.ndarray | tf.Tensor | None = None,
training: Optional[bool] = False,
) -> Union[TFTokenClassifierOutput, Tuple[tf.Tensor]]:
r"""
labels (`tf.Tensor` or `np.ndarray` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the token classification loss. Indices should be in `[0, ..., config.num_labels - 1]`.
"""
outputs = self.deberta(
input_ids=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,
training=training,
)
sequence_output = outputs[0]
sequence_output = self.dropout(sequence_output, training=training)
logits = self.classifier(inputs=sequence_output)
loss = None if labels is None else self.hf_compute_loss(labels=labels, logits=logits)
if not return_dict:
output = (logits,) + outputs[1:]
return ((loss,) + output) if loss is not None else output
return TFTokenClassifierOutput(
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 TFDebertaForQuestionAnswering(TFDebertaPreTrainedModel, TFQuestionAnsweringLoss):
def __init__(self, config: DebertaConfig, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.num_labels = config.num_labels
self.deberta = TFDebertaMainLayer(config, name="deberta")
self.qa_outputs = tf.keras.layers.Dense(
units=config.num_labels, kernel_initializer=get_initializer(config.initializer_range), name="qa_outputs"
)
@unpack_inputs
@add_start_docstrings_to_model_forward(DEBERTA_INPUTS_DOCSTRING.format("batch_size, sequence_length"))
@add_code_sample_docstrings(
checkpoint=_CHECKPOINT_FOR_DOC,
output_type=TFQuestionAnsweringModelOutput,
config_class=_CONFIG_FOR_DOC,
)
def call(
self,
input_ids: TFModelInputType | None = None,
attention_mask: np.ndarray | tf.Tensor | None = None,
token_type_ids: np.ndarray | tf.Tensor | None = None,
position_ids: np.ndarray | tf.Tensor | None = None,
inputs_embeds: np.ndarray | tf.Tensor | None = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
start_positions: np.ndarray | tf.Tensor | None = None,
end_positions: np.ndarray | tf.Tensor | None = None,
training: Optional[bool] = False,
) -> Union[TFQuestionAnsweringModelOutput, Tuple[tf.Tensor]]:
r"""
start_positions (`tf.Tensor` or `np.ndarray` 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 (`tf.Tensor` or `np.ndarray` 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.
"""
outputs = self.deberta(
input_ids=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,
training=training,
)
sequence_output = outputs[0]
logits = self.qa_outputs(inputs=sequence_output)
start_logits, end_logits = tf.split(value=logits, num_or_size_splits=2, axis=-1)
start_logits = tf.squeeze(input=start_logits, axis=-1)
end_logits = tf.squeeze(input=end_logits, axis=-1)
loss = None
if start_positions is not None and end_positions is not None:
labels = {"start_position": start_positions}
labels["end_position"] = end_positions
loss = self.hf_compute_loss(labels=labels, logits=(start_logits, end_logits))
if not return_dict:
output = (start_logits, end_logits) + outputs[2:]
return ((loss,) + output) if loss is not None else output
return TFQuestionAnsweringModelOutput(
loss=loss,
start_logits=start_logits,
end_logits=end_logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)