def _create_albert_model(cfg):
"""Creates an ALBERT keras core model from BERT configuration.
Args:
cfg: A `AlbertConfig` to create the core model.
Returns:
A keras model.
"""
albert_encoder = networks.AlbertEncoder(
vocab_size=cfg.vocab_size,
hidden_size=cfg.hidden_size,
embedding_width=cfg.embedding_size,
num_layers=cfg.num_hidden_layers,
num_attention_heads=cfg.num_attention_heads,
intermediate_size=cfg.intermediate_size,
activation=tf_utils.get_activation(cfg.hidden_act),
dropout_rate=cfg.hidden_dropout_prob,
attention_dropout_rate=cfg.attention_probs_dropout_prob,
max_sequence_length=cfg.max_position_embeddings,
type_vocab_size=cfg.type_vocab_size,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=cfg.initializer_range))
return albert_encoder
def build_encoder(config: EncoderConfig,
embedding_layer: Optional[tf.keras.layers.Layer] = None,
encoder_cls=None,
bypass_config: bool = False):
"""Instantiate a Transformer encoder network from EncoderConfig.
Args:
config: the one-of encoder config, which provides encoder parameters of a
chosen encoder.
embedding_layer: an external embedding layer passed to the encoder.
encoder_cls: an external encoder cls not included in the supported encoders,
usually used by gin.configurable.
bypass_config: whether to ignore config instance to create the object with
`encoder_cls`.
Returns:
An encoder instance.
"""
if bypass_config:
return encoder_cls()
encoder_type = config.type
encoder_cfg = config.get()
if encoder_cls and encoder_cls.__name__ == "EncoderScaffold":
embedding_cfg = dict(
vocab_size=encoder_cfg.vocab_size,
type_vocab_size=encoder_cfg.type_vocab_size,
hidden_size=encoder_cfg.hidden_size,
max_seq_length=encoder_cfg.max_position_embeddings,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
dropout_rate=encoder_cfg.dropout_rate,
)
hidden_cfg = dict(
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
intermediate_activation=tf_utils.get_activation(
encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
)
kwargs = dict(
embedding_cfg=embedding_cfg,
hidden_cfg=hidden_cfg,
num_hidden_instances=encoder_cfg.num_layers,
pooled_output_dim=encoder_cfg.hidden_size,
pooler_layer_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
return_all_layer_outputs=encoder_cfg.return_all_encoder_outputs,
dict_outputs=True)
return encoder_cls(**kwargs)
if encoder_type == "mobilebert":
return networks.MobileBERTEncoder(
word_vocab_size=encoder_cfg.word_vocab_size,
word_embed_size=encoder_cfg.word_embed_size,
type_vocab_size=encoder_cfg.type_vocab_size,
max_sequence_length=encoder_cfg.max_sequence_length,
num_blocks=encoder_cfg.num_blocks,
hidden_size=encoder_cfg.hidden_size,
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
intermediate_act_fn=encoder_cfg.hidden_activation,
hidden_dropout_prob=encoder_cfg.hidden_dropout_prob,
attention_probs_dropout_prob=encoder_cfg.
attention_probs_dropout_prob,
intra_bottleneck_size=encoder_cfg.intra_bottleneck_size,
initializer_range=encoder_cfg.initializer_range,
use_bottleneck_attention=encoder_cfg.use_bottleneck_attention,
key_query_shared_bottleneck=encoder_cfg.
key_query_shared_bottleneck,
num_feedforward_networks=encoder_cfg.num_feedforward_networks,
normalization_type=encoder_cfg.normalization_type,
classifier_activation=encoder_cfg.classifier_activation,
input_mask_dtype=encoder_cfg.input_mask_dtype)
if encoder_type == "albert":
return networks.AlbertEncoder(
vocab_size=encoder_cfg.vocab_size,
embedding_width=encoder_cfg.embedding_width,
hidden_size=encoder_cfg.hidden_size,
num_layers=encoder_cfg.num_layers,
num_attention_heads=encoder_cfg.num_attention_heads,
max_sequence_length=encoder_cfg.max_position_embeddings,
type_vocab_size=encoder_cfg.type_vocab_size,
intermediate_size=encoder_cfg.intermediate_size,
activation=tf_utils.get_activation(encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
dict_outputs=True)
if encoder_type == "bigbird":
# TODO(frederickliu): Support use_gradient_checkpointing and update
# experiments to use the EncoderScaffold only.
if encoder_cfg.use_gradient_checkpointing:
return bigbird_encoder.BigBirdEncoder(
vocab_size=encoder_cfg.vocab_size,
hidden_size=encoder_cfg.hidden_size,
num_layers=encoder_cfg.num_layers,
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
activation=tf_utils.get_activation(
encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
num_rand_blocks=encoder_cfg.num_rand_blocks,
block_size=encoder_cfg.block_size,
max_position_embeddings=encoder_cfg.max_position_embeddings,
type_vocab_size=encoder_cfg.type_vocab_size,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
embedding_width=encoder_cfg.embedding_width,
use_gradient_checkpointing=encoder_cfg.
use_gradient_checkpointing)
embedding_cfg = dict(
vocab_size=encoder_cfg.vocab_size,
type_vocab_size=encoder_cfg.type_vocab_size,
hidden_size=encoder_cfg.hidden_size,
max_seq_length=encoder_cfg.max_position_embeddings,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
dropout_rate=encoder_cfg.dropout_rate)
attention_cfg = dict(
num_heads=encoder_cfg.num_attention_heads,
key_dim=int(encoder_cfg.hidden_size //
encoder_cfg.num_attention_heads),
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
max_rand_mask_length=encoder_cfg.max_position_embeddings,
num_rand_blocks=encoder_cfg.num_rand_blocks,
from_block_size=encoder_cfg.block_size,
to_block_size=encoder_cfg.block_size,
)
hidden_cfg = dict(
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
intermediate_activation=tf_utils.get_activation(
encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
norm_first=encoder_cfg.norm_first,
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
attention_cls=layers.BigBirdAttention,
attention_cfg=attention_cfg)
kwargs = dict(
embedding_cfg=embedding_cfg,
hidden_cls=layers.TransformerScaffold,
hidden_cfg=hidden_cfg,
num_hidden_instances=encoder_cfg.num_layers,
mask_cls=layers.BigBirdMasks,
mask_cfg=dict(block_size=encoder_cfg.block_size),
pooled_output_dim=encoder_cfg.hidden_size,
pooler_layer_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
return_all_layer_outputs=False,
dict_outputs=True,
layer_idx_as_attention_seed=True)
return networks.EncoderScaffold(**kwargs)
if encoder_type == "kernel":
embedding_cfg = dict(
vocab_size=encoder_cfg.vocab_size,
type_vocab_size=encoder_cfg.type_vocab_size,
hidden_size=encoder_cfg.hidden_size,
max_seq_length=encoder_cfg.max_position_embeddings,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
dropout_rate=encoder_cfg.dropout_rate)
attention_cfg = dict(
num_heads=encoder_cfg.num_attention_heads,
key_dim=int(encoder_cfg.hidden_size //
encoder_cfg.num_attention_heads),
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
feature_transform=encoder_cfg.feature_transform,
num_random_features=encoder_cfg.num_random_features,
redraw=encoder_cfg.redraw,
is_short_seq=encoder_cfg.is_short_seq,
begin_kernel=encoder_cfg.begin_kernel,
scale=encoder_cfg.scale,
)
hidden_cfg = dict(
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
intermediate_activation=tf_utils.get_activation(
encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
norm_first=encoder_cfg.norm_first,
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
attention_cls=layers.KernelAttention,
attention_cfg=attention_cfg)
kwargs = dict(
embedding_cfg=embedding_cfg,
hidden_cls=layers.TransformerScaffold,
hidden_cfg=hidden_cfg,
num_hidden_instances=encoder_cfg.num_layers,
mask_cls=layers.KernelMask,
pooled_output_dim=encoder_cfg.hidden_size,
pooler_layer_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
return_all_layer_outputs=False,
dict_outputs=True,
layer_idx_as_attention_seed=True)
return networks.EncoderScaffold(**kwargs)
if encoder_type == "xlnet":
return networks.XLNetBase(
vocab_size=encoder_cfg.vocab_size,
num_layers=encoder_cfg.num_layers,
hidden_size=encoder_cfg.hidden_size,
num_attention_heads=encoder_cfg.num_attention_heads,
head_size=encoder_cfg.head_size,
inner_size=encoder_cfg.inner_size,
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
attention_type=encoder_cfg.attention_type,
bi_data=encoder_cfg.bi_data,
two_stream=encoder_cfg.two_stream,
tie_attention_biases=encoder_cfg.tie_attention_biases,
memory_length=encoder_cfg.memory_length,
clamp_length=encoder_cfg.clamp_length,
reuse_length=encoder_cfg.reuse_length,
inner_activation=encoder_cfg.inner_activation,
use_cls_mask=encoder_cfg.use_cls_mask,
embedding_width=encoder_cfg.embedding_width,
initializer=tf.keras.initializers.RandomNormal(
stddev=encoder_cfg.initializer_range))
if encoder_type == "teams":
embedding_cfg = dict(
vocab_size=encoder_cfg.vocab_size,
type_vocab_size=encoder_cfg.type_vocab_size,
hidden_size=encoder_cfg.hidden_size,
embedding_width=encoder_cfg.embedding_size,
max_seq_length=encoder_cfg.max_position_embeddings,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
dropout_rate=encoder_cfg.dropout_rate,
)
embedding_network = networks.PackedSequenceEmbedding(**embedding_cfg)
hidden_cfg = dict(
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
intermediate_activation=tf_utils.get_activation(
encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
)
kwargs = dict(
embedding_cfg=embedding_cfg,
embedding_cls=embedding_network,
hidden_cfg=hidden_cfg,
num_hidden_instances=encoder_cfg.num_layers,
pooled_output_dim=encoder_cfg.hidden_size,
pooler_layer_initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
return_all_layer_outputs=encoder_cfg.return_all_encoder_outputs,
dict_outputs=True)
return networks.EncoderScaffold(**kwargs)
# Uses the default BERTEncoder configuration schema to create the encoder.
# If it does not match, please add a switch branch by the encoder type.
return networks.BertEncoder(
vocab_size=encoder_cfg.vocab_size,
hidden_size=encoder_cfg.hidden_size,
num_layers=encoder_cfg.num_layers,
num_attention_heads=encoder_cfg.num_attention_heads,
intermediate_size=encoder_cfg.intermediate_size,
activation=tf_utils.get_activation(encoder_cfg.hidden_activation),
dropout_rate=encoder_cfg.dropout_rate,
attention_dropout_rate=encoder_cfg.attention_dropout_rate,
max_sequence_length=encoder_cfg.max_position_embeddings,
type_vocab_size=encoder_cfg.type_vocab_size,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=encoder_cfg.initializer_range),
output_range=encoder_cfg.output_range,
embedding_width=encoder_cfg.embedding_size,
embedding_layer=embedding_layer,
return_all_encoder_outputs=encoder_cfg.return_all_encoder_outputs,
dict_outputs=True,
norm_first=encoder_cfg.norm_first)
def get_transformer_encoder(bert_config,
sequence_length=None,
transformer_encoder_cls=None,
output_range=None):
"""Gets a 'TransformerEncoder' object.
Args:
bert_config: A 'modeling.BertConfig' or 'modeling.AlbertConfig' object.
sequence_length: [Deprecated].
transformer_encoder_cls: A EncoderScaffold class. If it is None, uses the
default BERT encoder implementation.
output_range: the sequence output range, [0, output_range). Default setting
is to return the entire sequence output.
Returns:
A encoder object.
"""
del sequence_length
if transformer_encoder_cls is not None:
# TODO(hongkuny): evaluate if it is better to put cfg definition in gin.
embedding_cfg = dict(
vocab_size=bert_config.vocab_size,
type_vocab_size=bert_config.type_vocab_size,
hidden_size=bert_config.hidden_size,
max_seq_length=bert_config.max_position_embeddings,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=bert_config.initializer_range),
dropout_rate=bert_config.hidden_dropout_prob,
)
hidden_cfg = dict(
num_attention_heads=bert_config.num_attention_heads,
intermediate_size=bert_config.intermediate_size,
intermediate_activation=tf_utils.get_activation(
bert_config.hidden_act),
dropout_rate=bert_config.hidden_dropout_prob,
attention_dropout_rate=bert_config.attention_probs_dropout_prob,
kernel_initializer=tf.keras.initializers.TruncatedNormal(
stddev=bert_config.initializer_range),
)
kwargs = dict(
embedding_cfg=embedding_cfg,
hidden_cfg=hidden_cfg,
num_hidden_instances=bert_config.num_hidden_layers,
pooled_output_dim=bert_config.hidden_size,
pooler_layer_initializer=tf.keras.initializers.TruncatedNormal(
stddev=bert_config.initializer_range))
# Relies on gin configuration to define the Transformer encoder arguments.
return transformer_encoder_cls(**kwargs)
kwargs = dict(
vocab_size=bert_config.vocab_size,
hidden_size=bert_config.hidden_size,
num_layers=bert_config.num_hidden_layers,
num_attention_heads=bert_config.num_attention_heads,
intermediate_size=bert_config.intermediate_size,
activation=tf_utils.get_activation(bert_config.hidden_act),
dropout_rate=bert_config.hidden_dropout_prob,
attention_dropout_rate=bert_config.attention_probs_dropout_prob,
max_sequence_length=bert_config.max_position_embeddings,
type_vocab_size=bert_config.type_vocab_size,
embedding_width=bert_config.embedding_size,
initializer=tf.keras.initializers.TruncatedNormal(
stddev=bert_config.initializer_range))
if isinstance(bert_config, albert_configs.AlbertConfig):
return networks.AlbertEncoder(**kwargs)
else:
assert isinstance(bert_config, configs.BertConfig)
kwargs['output_range'] = output_range
return networks.BertEncoder(**kwargs)