def _build_summarization_model(self):
is_training = self.is_training
config = self.bert_config
gpu_pred_ids = []
gpu_logits = []
gpu_train_encoded = []
gpu_loss = []
gpu_out_embed = []
gpu_grads = []
self._add_placeholders()
self._n_gpu_split_placeholders(self.hps.n_gpu)
for i in range(self.hps.n_gpu):
do_reuse = True if i > 0 else None
with tf.device(assign_to_gpu(i, "/gpu:0")), tf.variable_scope(tf.get_variable_scope(), reuse=do_reuse):
'''Creates a classification model.'''
model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=self.input_ids_ngpu[i],
input_mask=self.input_mask_ngpu[i],
token_type_ids=self.segment_ids_ngpu[i],
use_one_hot_embeddings=self.hps.use_tpu) # use_one_hot_embeddings=Flags.tpu ?
encoder_output = model.get_sequence_output() # [b, l_s, h]
hidden_size = encoder_output.shape[2].value
encoder_out_length = tf.shape(encoder_output)[1]
expand_topic_id = tf.expand_dims(self.topic_ids_ngpu[i], -1)
topic_input_sequence = tf.tile(expand_topic_id, [1, encoder_out_length])
with tf.variable_scope('topic'):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(self.topic_embed, self.topic_embeddings) = embedding_lookup(
input_ids=topic_input_sequence, # here the embedding input of decoder have to be output_ids
vocab_size=self.hps.num_topic, # decode dictionary modified
embedding_size=self.hps.topic_embedding_size,
initializer_range=config.initializer_range,
word_embedding_name='topic_embeddings',
use_one_hot_embeddings=False)
print('!!!!topic_embeddings', self.topic_embeddings, self.topic_embed)
self.encoder_output = tf.concat([encoder_output, self.topic_embed], -1)
self.enc_attn_bias = attention_bias(self.input_mask_ngpu[i], 'masking')
out_dict_size = len(self.hps.vocab_out)
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(self.out_embed, self.bert_embeddings) = embedding_lookup(
input_ids=self.output_ids_ngpu[i], # here the embedding input of decoder have to be output_ids
vocab_size=out_dict_size, # decode dictionary modified
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
self.out_embed = embedding_postprocessor(
input_tensor=self.out_embed,
use_token_type=True,
token_type_ids=self.out_segment_ids_ngpu[i],
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decode'):
self.decoder_weights = self.bert_embeddings
self.masked_out_embed = self.out_embed * tf.expand_dims(self.output_mask_ngpu[i], -1)
self.dec_attn_bias = attention_bias(tf.shape(self.masked_out_embed)[1], 'causal')
self.decoder_input = tf.pad(self.masked_out_embed, [[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
self.all_att_weights, self.decoder_output = transformer_decoder(self.decoder_input,
self.encoder_output,
self.dec_attn_bias,
self.enc_attn_bias,
self.hps)
# [b, l_t, e] => [b*l_t, v]
self.decoder_output = tf.reshape(self.decoder_output, [-1, hidden_size])
self.vocab_logits = tf.matmul(self.decoder_output, self.decoder_weights, False, True) # (b * l_t, v)
self.vocab_probs = tf.nn.softmax(self.vocab_logits) # [b * l_t, v]
# vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy'):
self.single_logits = calculate_final_logits(self.decoder_output, self.all_att_weights, self.vocab_probs,
self.input_ids_oo_ngpu[i], self.max_out_oovs, self.input_mask_ngpu[i],
out_dict_size,
self.tiled_len) # [b * l_t, v + v']
self.single_pred_ids = tf.reshape(tf.argmax(self.single_logits, axis=-1), [self.batch_size, -1])
with tf.variable_scope('loss'):
self.single_ce = smooth_cross_entropy(
self.single_logits,
self.output_label_ngpu[i],
self.hps.label_smoothing)
self.single_ce = tf.reshape(self.single_ce, tf.shape(self.output_label_ngpu[i])) # [b, l_t]
self.single_loss = tf.reduce_sum(self.single_ce * self.output_mask_ngpu[i]) / tf.reduce_sum(self.output_mask_ngpu[i]) # scalar
gpu_pred_ids.append(self.single_pred_ids)
gpu_logits.append(self.single_logits)
gpu_train_encoded.append(self.encoder_output)
gpu_loss.append(self.single_loss)
gpu_out_embed.append(self.out_embed)
params = tf.trainable_variables()
grads = tf.gradients(self.single_loss, params)
grads = list(zip(grads, params))
gpu_grads.append(grads)
#gpu_ops.append([loss, logits])
self.pred_ids = tf.concat(gpu_pred_ids, axis=0)
self.logits = tf.concat(gpu_logits, axis=0)
self.loss = tf.reduce_mean(gpu_loss)
self.encoder_output = tf.concat(gpu_train_encoded, axis=0)
self.out_embed = tf.concat(gpu_out_embed, axis=0)
# end for
grads = sum_grads(gpu_grads)
grads = [g for g, p in grads]
self.total_gradient = grads
tf.summary.scalar('loss', self.loss)
def decode_infer(self, inputs, state):
# state['enc']: [b * beam, l_s, e] , state['dec']: [b * beam, q', e]
# q' = previous decode output length
# during infer, following graph are constructed using beam search
with self.graph.as_default():
config = self.bert_config
target_sequence = inputs['target'] # [b * beam, q']
vocab_size = len(self.hps.vocab_out)
# trunct word idx, change those greater than vocab_size to unkId
shape = target_sequence.shape
unkid = self.hps.vocab_out[self.hps.unk]
# target_sequence = tf_trunct(target_sequence, vocab_size, self.hps.unkId)
target_sequence = tf_trunct(target_sequence, vocab_size, unkid)
target_sequence.set_shape(shape)
target_length = inputs['target_length']
target_seg_ids = tf.zeros_like(target_sequence, dtype=tf.int32, name='target_seg_ids_infer')
tgt_mask = tf.sequence_mask(target_length,
maxlen=tf.shape(target_sequence)[1],
dtype=tf.float32) # [b, q']
# with tf.variable_scope('bert', reuse=True):
out_dict_size = len(self.hps.vocab_out)
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(tgt_embed, _) = embedding_lookup(
input_ids=target_sequence,
vocab_size=out_dict_size, # out vocab size
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
tgt_embed = embedding_postprocessor(
input_tensor=tgt_embed,
use_token_type=True,
token_type_ids=target_seg_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decode', reuse=True):
# [b, q', e]
masked_tgt_embed = tgt_embed * tf.expand_dims(tgt_mask, -1)
dec_attn_bias = attention_bias(tf.shape(masked_tgt_embed)[1], "causal")
decoder_input = tf.pad(masked_tgt_embed, [[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
infer_decoder_input = decoder_input[:, -1:, :]
infer_dec_attn_bias = dec_attn_bias[:, :, -1:, :]
ret = transformer_decoder(infer_decoder_input,
self.enc_output,
infer_dec_attn_bias,
self.enc_attn_bias,
self.hps,
state=state['decoder'])
all_att_weights, decoder_output, decoder_state = ret
decoder_output = decoder_output[:, -1, :] # [b * beam, e]
vocab_logits = tf.matmul(decoder_output, self.decoder_weights, False, True) # [b * beam, v]
vocab_probs = tf.nn.softmax(vocab_logits)
vocab_size = out_dict_size # out vocabsize
# we have tiled source_id_oo before feed, so last argument is set to 1
with tf.variable_scope('copy'):
logits = calculate_final_logits(decoder_output, all_att_weights,
vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask, vocab_size,
tgt_seq_len=1)
log_prob = tf.log(logits) # [b * beam, v + v']
return log_prob, {'encoder': state['encoder'], 'decoder': decoder_state}
def decode_infer_sent(self):
# stage 2, sentence level inference using decoded sequence
# l_t = decode sequence length
# during infer, following graph are constructed using beam search
hidden_size = self.bert_config.hidden_size
with self.graph.as_default():
config = self.bert_config
target_sequence = tf.squeeze(self.decode_seq, axis=1)
target_sequence = self.trunct(target_sequence)
target_length = self.decode_length
target_seg_ids = tf.zeros_like(target_sequence,
dtype=tf.int32,
name='target_seg_ids_infer_2')
tgt_mask = tf.sequence_mask(target_length,
maxlen=tf.shape(target_sequence)[1],
dtype=tf.float32) # [b, q']
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(tgt_embed, _) = embedding_lookup(
input_ids=target_sequence,
vocab_size=config.vocab_size,
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
tgt_embed = embedding_postprocessor(
input_tensor=tgt_embed,
use_token_type=True,
token_type_ids=target_seg_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decoder', reuse=True):
masked_tgt_embed = tgt_embed * tf.expand_dims(tgt_mask, -1)
infer_decoder_input = tf.pad(
masked_tgt_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
all_att_weights, decoder_output = transformer_decoder(
infer_decoder_input,
self.enc_output,
self.sent_level_attn_bias,
self.enc_attn_bias,
self.hps,
scope='t_decoder')
# [b, l_t, e] => [b*l_t, v]
seq_len = tf.shape(decoder_output)[1]
decoder_output = tf.reshape(decoder_output, [-1, hidden_size])
second_logits = tf.matmul(decoder_output, self.decoder_weights,
False, True) # (b*l_t, v)
vocab_probs = tf.nn.softmax(second_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
infer_sent_rep = tf.reshape(
tf.tile(self.infer_sentence_rep, [1, seq_len, 1]),
[-1, self.hps.hidden_size])
copy_rep = tf.concat([infer_sent_rep, decoder_output],
axis=-1) # [b * l_t, 2 * e]
logits = calculate_final_logits(
copy_rep, all_att_weights, vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size, self.infer_tiled_len) # [b * l_t, v + v']
second_log_prob = tf.log(logits)
# (b, l_t, v)
extend_vocab_size = tf.add(tf.constant(vocab_size),
self.max_out_oovs)
second_log_prob = tf.reshape(
second_log_prob,
[-1, tf.shape(target_sequence)[1], extend_vocab_size])
second_log_id = tf.argmax(second_log_prob, axis=-1) # (b, l_t)
return second_log_id
def _build_summarization_model(self):
is_training = self.is_training
config = self.bert_config
self._add_placeholders()
'''Creates a classification model.'''
model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=self.input_ids,
input_mask=self.input_mask,
token_type_ids=self.segment_ids,
use_one_hot_embeddings=self.hps.use_tpu) # use_one_hot_embeddings=Flags.tpu ?
encoder_output = model.get_sequence_output() # [b, l_s, h]
self.encoder_output = encoder_output
hidden_size = encoder_output.shape[2].value
self.enc_attn_bias = attention_bias(self.input_mask, 'masking')
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(self.out_embed, self.bert_embeddings) = embedding_lookup(
input_ids=self.output_ids, # here the embedding input of decoder have to be output_ids
vocab_size=config.vocab_size,
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
self.out_embed = embedding_postprocessor(
input_tensor=self.out_embed,
use_token_type=True,
token_type_ids=self.out_segment_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decode'):
self.decoder_weights = self.bert_embeddings
self.masked_out_embed = self.out_embed * tf.expand_dims(self.output_mask, -1)
self.dec_attn_bias = attention_bias(tf.shape(self.masked_out_embed)[1], 'causal')
self.decoder_input = tf.pad(self.masked_out_embed, [[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
self.all_att_weights, self.decoder_output = transformer_decoder(self.decoder_input,
self.encoder_output,
self.dec_attn_bias,
self.enc_attn_bias,
self.hps)
# [b, l_t, e] => [b*l_t, v]
self.decoder_output = tf.reshape(self.decoder_output, [-1, hidden_size])
self.vocab_logits = tf.matmul(self.decoder_output, self.decoder_weights, False, True) # (b * l_t, v)
self.vocab_probs = tf.nn.softmax(self.vocab_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy'):
self.logits = calculate_final_logits(self.decoder_output, self.all_att_weights, self.vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask, vocab_size,
self.tiled_len) # [b * l_t, v + v']
with tf.variable_scope('loss'):
self.ce = smooth_cross_entropy(
self.logits,
self.output_label,
self.hps.label_smoothing)
self.ce = tf.reshape(self.ce, tf.shape(self.output_label)) # [b, l_t]
self.loss = tf.reduce_sum(self.ce * self.output_mask) / tf.reduce_sum(self.output_mask) # scalar
tf.summary.scalar('loss', self.loss)
def _build_summarization_model(self):
is_training = self.is_training
config = self.bert_config
self._add_placeholders()
'''Creates a classification model.'''
model = modeling.BertModel(config=self.bert_config,
is_training=is_training,
input_ids=self.input_ids,
input_mask=self.input_mask,
token_type_ids=self.segment_ids,
use_one_hot_embeddings=self.hps.use_tpu
) # use_one_hot_embeddings=Flags.tpu ?
encoder_output = model.get_sequence_output() # [b, l_s, h]
self.encoder_output = encoder_output
hidden_size = encoder_output.shape[2].value
self.enc_attn_bias = attention_bias(self.input_mask, 'masking')
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(self.out_embed, self.bert_embeddings) = embedding_lookup(
input_ids=self.output_ids,
vocab_size=config.vocab_size,
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
self.out_embed = embedding_postprocessor(
input_tensor=self.out_embed,
use_token_type=True,
token_type_ids=self.out_segment_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decoder_1'):
self.decoder_weights = self.bert_embeddings
self.masked_out_embed = self.out_embed * tf.expand_dims(
self.output_mask, -1)
self.decoder_input = tf.pad(
self.masked_out_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
# ################################################### decoding train - 1
self.dec_attn_bias = attention_bias(
tf.shape(self.masked_out_embed)[1], 'causal')
self.all_att_weights, self.decoder_output_1 = transformer_decoder(
self.decoder_input,
self.encoder_output,
self.dec_attn_bias,
self.enc_attn_bias,
self.hps,
scope='decoder_1')
# [b, l_t, e] => [b*l_t, v]
self.decoder_output_1 = tf.reshape(self.decoder_output_1,
[-1, hidden_size])
self.vocab_logits = tf.matmul(self.decoder_output_1,
self.decoder_weights, False,
True) # (b*l_t, v)
self.vocab_probs = tf.nn.softmax(self.vocab_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
self.logits = calculate_final_logits(
self.decoder_output_1, self.all_att_weights,
self.vocab_probs, self.input_ids_oo, self.max_out_oovs,
self.input_mask, vocab_size,
self.tiled_len) # [b * l_t, v + v']
self.pred_ids = tf.reshape(tf.argmax(self.logits, axis=-1),
[self.batch_size, -1]) # [b, l_t]
draft = self.trunct(
self.pred_ids
) # as the draft may have copy words, we transform them to UNK first
draft = tf.cast(draft, tf.int32)
changed_ids = tf.concat([self.output_ids, draft],
axis=-1) # [b, 2 * l_t]
change_segment_ids = tf.zeros_like(changed_ids,
dtype=tf.int32,
name='change_segment_ids')
def calcu_id_len(input_tensor):
step_size = tf.constant(0.001)
a = input_tensor
res = tf.argmin(
tf.cast(a, tf.float32) +
tf.cast(tf.range(0,
tf.shape(a)[-1]), tf.float32) * step_size,
-1) + 1
return res
pred_ids_len = calcu_id_len(draft) # [b,]
pred_ids_mask_w_draft = tf.sequence_mask(pred_ids_len,
maxlen=tf.shape(draft)[1],
dtype=tf.float32) # [b, l_t]
pred_ids_mask_wo_draft = tf.zeros_like(draft, dtype=tf.float32)
pred_ids_mask = tf.cond(self.feed_draft, lambda: pred_ids_mask_w_draft,
lambda: pred_ids_mask_wo_draft)
change_ids_mask = tf.concat([self.output_mask, pred_ids_mask],
axis=-1) # [b, 2 * l_t]
transferred_mask = create_attention_mask_from_input_mask(
changed_ids, change_ids_mask) # [b, 2 * l_t, 2 * l_t]
self.second_dec_attn_bias_w_draft = attention_bias(
tf.shape(changed_ids)[1], 'mask_draft')
self.second_dec_attn_bias_wo_draft = attention_bias(
tf.shape(changed_ids)[1], 'mask_draft_warmup')
self.second_dec_attn_bias = tf.cond(
self.feed_draft, lambda: self.second_dec_attn_bias_w_draft, lambda:
self.second_dec_attn_bias_wo_draft) # [1, 1, 2 * l_t, 2 *l_t]
self.second_dec_attn_bias = tf.tile(
self.second_dec_attn_bias, [tf.shape(self.output_ids)[0], 1, 1, 1
]) # [b, 1, 2 * l_t, 2 * l_t]
self.second_dec_attn_bias = self.second_dec_attn_bias * tf.expand_dims(
transferred_mask, 1) # [b, 1, 2 * l_t, 2 * l_t]
dec_model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=changed_ids,
input_mask=tf.squeeze(self.second_dec_attn_bias,
1), # [b, 2 * l_t, 2 * l_t]
token_type_ids=change_segment_ids,
scope='bert',
reuse=tf.AUTO_REUSE,
use_one_hot_embeddings=self.hps.use_tpu
) # use_one_hot_embeddings=Flags.tpu ?
dec_output = dec_model.get_sequence_output() # [b, l_t, h]
self.out_embed = dec_output
self.masked_out_embed = self.out_embed * tf.expand_dims(
change_ids_mask, -1)
self.decoder_input = tf.pad(
self.masked_out_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
# ################################################### decoding train - 2
with tf.variable_scope('decoder_2'):
self.all_att_weights, self.decoder_output_2 = transformer_decoder(
self.decoder_input,
self.encoder_output, (1.0 - self.second_dec_attn_bias) * -1e9,
self.enc_attn_bias,
self.hps,
scope='decoder_2')
# [b, 2 * l_t, e] => [b, l_t, e] => [b * l_t, v]
target_len = tf.shape(self.output_ids)[1]
# keep only ground-truth part for attention weight & decoder output
self.all_att_weights[-1] = self.all_att_weights[
-1][:, :target_len, :] # [b, l_t, l_s]
self.decoder_output_2 = self.decoder_output_2[:, :
target_len, :] # [b, l_t, v]
self.decoder_output_2 = tf.reshape(self.decoder_output_2,
[-1, hidden_size])
self.second_logits = tf.matmul(self.decoder_output_2,
self.decoder_weights, False,
True) # (b*l_t, v)
self.vocab_probs_2 = tf.nn.softmax(
self.second_logits) # [b * l_t, v]
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
self.second_logits = calculate_final_logits(
self.decoder_output_2, self.all_att_weights,
self.vocab_probs_2, self.input_ids_oo, self.max_out_oovs,
self.input_mask, vocab_size,
self.tiled_len) # [b * l_t, v + v']
with tf.variable_scope('loss'):
self.ce = smooth_cross_entropy(self.logits, self.output_label,
self.hps.label_smoothing)
self.ce = tf.reshape(self.ce,
tf.shape(self.output_label)) # [b, l_t]
mle_1 = tf.reduce_sum(
self.ce * self.output_mask, -1) / tf.reduce_sum(
self.output_mask, -1) # [b]
self.first_loss = tf.reduce_sum(self.ce * self.output_mask,
-1) / tf.reduce_sum(
self.output_mask, -1)
self.first_loss = tf.reduce_mean(self.first_loss) # scalar
self.second_ce = smooth_cross_entropy(self.second_logits,
self.output_label,
self.hps.label_smoothing)
self.second_ce = tf.reshape(self.second_ce,
tf.shape(
self.output_label)) # [b, l_t]
output_mask = self.output_mask
mle_2 = tf.reduce_sum(self.second_ce * output_mask, -1) / (
tf.reduce_sum(output_mask, -1)) # [b]
self.second_loss = tf.reduce_mean(
tf.reduce_sum(self.second_ce * output_mask, -1) /
(tf.reduce_sum(output_mask, -1))) # scalar
mle = mle_1 + mle_2
self.rl_loss = tf.reduce_mean(mle * self.reward) # scalar
self.ml_loss = self.first_loss + self.second_loss
self.loss = self.hps.rl_lambda * self.rl_loss + (
1 - self.hps.rl_lambda) * self.ml_loss
tf.summary.scalar('first_loss', self.first_loss)
tf.summary.scalar('second_loss', self.second_loss)
tf.summary.scalar('reward', tf.reduce_mean(self.reward))
tf.summary.scalar('rl_loss', self.rl_loss)
tf.summary.scalar('ml_loss', self.ml_loss)
tf.summary.scalar('loss', self.loss)
def decode_infer(self, inputs, state):
# state['enc']: [b * beam, l_s, e] , state['dec']: [b * beam, q', e]
# q' = previous decode output length
# during infer, following graph are constructed using beam search
with self.graph.as_default():
config = self.bert_config
target_sequence = inputs['target']
target_sequence = self.trunct(target_sequence)
target_length = inputs['target_length']
target_seg_ids = tf.zeros_like(target_sequence,
dtype=tf.int32,
name='target_seg_ids_infer')
tgt_mask = tf.sequence_mask(target_length,
maxlen=tf.shape(target_sequence)[1],
dtype=tf.float32) # [b, q']
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(tgt_embed, _) = embedding_lookup(
input_ids=target_sequence,
vocab_size=config.vocab_size,
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
tgt_embed = embedding_postprocessor(
input_tensor=tgt_embed,
use_token_type=True,
token_type_ids=target_seg_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decoder', reuse=True):
# [b, l_t, e]
masked_tgt_embed = tgt_embed * tf.expand_dims(tgt_mask, -1)
dec_attn_bias = attention_bias(
tf.shape(masked_tgt_embed)[1], "causal")
decoder_input = tf.pad(
masked_tgt_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
infer_decoder_input = decoder_input[:, -1:, :]
infer_dec_attn_bias = dec_attn_bias[:, :, -1:, :]
all_att_weights, decoder_output, decoder_state = transformer_decoder(
infer_decoder_input,
self.enc_output,
infer_dec_attn_bias,
self.enc_attn_bias,
self.hps,
state=state['decoder'],
scope='t_decoder')
decoder_output = decoder_output[:, -1, :] # [b * beam, e]
logits = tf.matmul(decoder_output, self.decoder_weights, False,
True) # [b * beam, v]
vocab_probs = tf.nn.softmax(logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
copy_rep = tf.concat(
[self.tiled_sentence_rep, decoder_output],
axis=-1) # [b * beam, 2 * e]
logits = calculate_final_logits(
copy_rep, all_att_weights, vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size, 1) # [b * l_t, v + v']
log_prob = tf.log(logits)
return log_prob, {
'encoder': state['encoder'],
'decoder': decoder_state
}
def decode_infer_2(self):
# stage 2, word level inference using decoded sequence
# l_t = decode sequence length
# during infer, following graph are constructed using beam search
hidden_size = self.bert_config.hidden_size
with self.graph.as_default():
target_sequence = tf.squeeze(self.decode_seq, axis=1)
draft = self.trunct(
target_sequence
) # as the draft may have copy words, we transform them to UNK first
target_sequence = self.trunct(target_sequence)
target_length = self.decode_length
tgt_mask = tf.sequence_mask(target_length,
maxlen=tf.shape(target_sequence)[1],
dtype=tf.float32) # [b, q']
draft = tf.cast(draft, tf.int32)
changed_ids = tf.concat([target_sequence, draft],
axis=-1) # [b, 2 * l_t]
change_segment_ids = tf.zeros_like(changed_ids,
dtype=tf.int32,
name='change_segment_ids')
def calcu_id_len(input_tensor):
step_size = tf.constant(0.001)
a = input_tensor
res = tf.argmin(
tf.cast(a, tf.float32) +
tf.cast(tf.range(0,
tf.shape(a)[-1]), tf.float32) * step_size,
-1) + 1
return res
pred_ids_len = calcu_id_len(draft) # [b,]
pred_ids_mask_w_draft = tf.sequence_mask(
pred_ids_len, maxlen=tf.shape(draft)[1],
dtype=tf.float32) # [b, l_t]
pred_ids_mask = pred_ids_mask_w_draft
change_ids_mask = tf.concat([tgt_mask, pred_ids_mask],
axis=-1) # [b, 2 * l_t]
transferred_mask = create_attention_mask_from_input_mask(
changed_ids, change_ids_mask) # [b, 2 * l_t, 2 * l_t]
second_dec_attn_bias_w_draft = attention_bias(
tf.shape(changed_ids)[1], 'mask_draft')
second_dec_attn_bias = second_dec_attn_bias_w_draft # [1, 1, 2 * l_t, 2 *l_t]
second_dec_attn_bias = tf.tile(
second_dec_attn_bias, [tf.shape(target_sequence)[0], 1, 1, 1
]) # [b, 1, 2 * l_t, 2 * l_t]
second_dec_attn_bias = second_dec_attn_bias * tf.expand_dims(
transferred_mask, 1) # [b, 1, 2 * l_t, 2 * l_t]
is_training = self.is_training
dec_model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=changed_ids,
input_mask=tf.squeeze(second_dec_attn_bias,
1), # [b, 2 * l_t, 2 * l_t]
token_type_ids=change_segment_ids,
scope='bert',
reuse=tf.AUTO_REUSE,
use_one_hot_embeddings=self.hps.use_tpu)
dec_output = dec_model.get_sequence_output() # [b, l_t, h]
tgt_embed = dec_output
with tf.variable_scope('decoder_2', reuse=True):
masked_tgt_embed = tgt_embed * tf.expand_dims(
change_ids_mask, -1)
infer_decoder_input = tf.pad(
masked_tgt_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
all_att_weights, decoder_output = transformer_decoder(
infer_decoder_input,
self.enc_output, (1.0 - second_dec_attn_bias) * -1e9,
self.enc_attn_bias,
self.hps,
scope='decoder_2')
# [b, l_t, e] => [b*l_t, v]
target_len = tf.shape(target_sequence)[1]
# keep only ground-truth part for attention weight & decoder output
all_att_weights[-1] = all_att_weights[
-1][:, :target_len, :] # [b, l_t, l_s]
decoder_output = decoder_output[:, :
target_len, :] # [b, l_t, v]
decoder_output = tf.reshape(decoder_output, [-1, hidden_size])
second_logits = tf.matmul(decoder_output, self.decoder_weights,
False, True) # (b*l_t, v)
vocab_probs = tf.nn.softmax(second_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
logits = calculate_final_logits(
decoder_output, all_att_weights, vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size, self.infer_tiled_len) # [b * l_t, v + v']
second_log_prob = tf.log(logits)
# (b, l_t, v)
extend_vocab_size = tf.add(tf.constant(vocab_size),
self.max_out_oovs)
second_log_prob = tf.reshape(
second_log_prob,
[-1, tf.shape(target_sequence)[1], extend_vocab_size])
second_log_id = tf.argmax(second_log_prob, axis=-1) # (b, l_t)
return second_log_id
def decode_infer_2_bs(self):
# beam search version
# during second stage decoding, we have a decoded sequence, so do not need to feed state(no incremental dec)
# at time i, we calculate i-th attn_bias, get i-th decoder output
with self.graph.as_default():
target_sequence = tf.reshape(
self.decode_seq,
[self.hps.eval_batch_size * self.hps.beam_size, -1])
draft = self.trunct(
target_sequence
) # as the draft may have copy words, we transform them to UNK first
target_sequence = self.trunct(target_sequence)
target_length = self.decode_length
tgt_mask = tf.sequence_mask(target_length,
maxlen=tf.shape(target_sequence)[1],
dtype=tf.float32) # [b, l_t]
draft = tf.cast(draft, tf.int32)
changed_ids = tf.concat([target_sequence, draft],
axis=-1) # [b, 2 * l_t]
change_segment_ids = tf.zeros_like(changed_ids,
dtype=tf.int32,
name='change_segment_ids')
def calcu_id_len(input_tensor):
step_size = tf.constant(0.001)
a = input_tensor
res = tf.argmin(
tf.cast(a, tf.float32) +
tf.cast(tf.range(0,
tf.shape(a)[-1]), tf.float32) * step_size,
-1) + 1
return res
pred_ids_len = calcu_id_len(draft) # [b,]
pred_ids_mask_w_draft = tf.sequence_mask(
pred_ids_len, maxlen=tf.shape(draft)[1],
dtype=tf.float32) # [b, l_t]
pred_ids_mask = pred_ids_mask_w_draft
change_ids_mask = tf.concat([tgt_mask, pred_ids_mask],
axis=-1) # [b, 2 * l_t]
transferred_mask = create_attention_mask_from_input_mask(
changed_ids, change_ids_mask) # [b, 2 * l_t, 2 * l_t]
second_dec_attn_bias_w_draft = attention_bias(
tf.shape(changed_ids)[1], 'mask_draft')
second_dec_attn_bias = second_dec_attn_bias_w_draft # [1, 1, 2 * l_t, 2 *l_t]
second_dec_attn_bias = tf.tile(
second_dec_attn_bias, [tf.shape(target_sequence)[0], 1, 1, 1
]) # [b, 1, 2 * l_t, 2 * l_t]
second_dec_attn_bias = second_dec_attn_bias * tf.expand_dims(
transferred_mask, 1) # [b, 1, 2 * l_t, 2 * l_t]
is_training = self.is_training
dec_model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=changed_ids,
input_mask=tf.squeeze(second_dec_attn_bias,
1), # [b, 2 * l_t, 2 * l_t]
token_type_ids=change_segment_ids,
scope='bert',
reuse=tf.AUTO_REUSE,
use_one_hot_embeddings=self.hps.use_tpu)
dec_output = dec_model.get_sequence_output() # [b, l_t, h]
tgt_embed = dec_output
with tf.variable_scope('decoder_2', reuse=True):
# [b, l_t, e]
masked_tgt_embed = tgt_embed * tf.expand_dims(
change_ids_mask, -1)
infer_decoder_input = tf.pad(
masked_tgt_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
all_att_weights, decoder_output = transformer_decoder(
infer_decoder_input,
self.enc_output, (1.0 - second_dec_attn_bias) * -1e9,
self.enc_attn_bias,
self.hps,
scope='decoder_2')
decoder_output = decoder_output[:, self.
time_step, :] # [b * beam, e]
all_att_weights[-1] = all_att_weights[-1][:, self.time_step, :]
second_logits = tf.matmul(decoder_output, self.decoder_weights,
False, True) # (b*beam, v)
vocab_probs = tf.nn.softmax(second_logits) # [b * beam, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
logits = calculate_final_logits(
decoder_output, all_att_weights, vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size, 1) # [b * beam, v + v']
second_log_prob = tf.log(logits)
return second_log_prob
def _build_summarization_model(self):
is_training = self.is_training
config = self.bert_config
self._add_placeholders()
'''Creates a classification model.'''
model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=self.input_ids,
input_mask=self.input_mask,
token_type_ids=self.segment_ids,
use_one_hot_embeddings=self.hps.use_tpu) # use_one_hot_embeddings=Flags.tpu ?
batch_size = tf.shape(self.output_ids)[0]
tgt_len = tf.shape(self.output_ids)[1]
rnd_value = tf.random_uniform([batch_size, tgt_len], minval=0, maxval=1)
replace_to_mask = rnd_value < 0.1
replace_to_random_word = (rnd_value > 0.1) & (rnd_value < 0.15)
keep_the_word = rnd_value < 0.2
keep_the_word = tf.cast(keep_the_word, tf.float32)
all_mask = tf.ones_like(self.output_ids, dtype=tf.int32)
mask_id = self.hps.maskId
all_mask = all_mask * mask_id
all_random_word_id = tf.random_uniform([batch_size, tgt_len], minval=999, maxval=30521, dtype=tf.int32)
changed_ids = self.output_ids
changed_ids = tf.where(replace_to_mask, all_mask, changed_ids)
changed_ids = tf.where(replace_to_random_word, all_random_word_id, changed_ids)
dec_model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=changed_ids,
input_mask=self.output_mask,
token_type_ids=self.out_segment_ids,
scope='bert',
reuse=tf.AUTO_REUSE,
use_one_hot_embeddings=self.hps.use_tpu) # use_one_hot_embeddings=Flags.tpu ?
encoder_output = model.get_sequence_output() # [b, l_s, h]
dec_output = dec_model.get_sequence_output() # [b, l_t, h]
self.encoder_output = encoder_output
hidden_size = encoder_output.shape[2].value
self.enc_attn_bias = attention_bias(self.input_mask, 'masking')
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(self.out_embed, self.bert_embeddings) = embedding_lookup(
input_ids=self.output_ids,
vocab_size=config.vocab_size,
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
self.out_embed = embedding_postprocessor(
input_tensor=self.out_embed,
use_token_type=True,
token_type_ids=self.out_segment_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decoder'):
self.decoder_weights = self.bert_embeddings
self.masked_out_embed = self.out_embed * tf.expand_dims(self.output_mask, -1)
self.decoder_input = tf.pad(self.masked_out_embed, [[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
# ################################################### decoding train - 1
self.dec_attn_bias = attention_bias(tf.shape(self.masked_out_embed)[1], 'causal')
self.all_att_weights, self.decoder_output_1 = transformer_decoder(self.decoder_input, self.encoder_output,
self.dec_attn_bias, self.enc_attn_bias,
self.hps, scope='t_decoder')
# [b, l_t, e] => [b*l_t, v]
self.decoder_output_1 = tf.reshape(self.decoder_output_1, [-1, hidden_size])
self.vocab_logits = tf.matmul(self.decoder_output_1, self.decoder_weights, False, True) # (b*l_t, v)
self.vocab_probs = tf.nn.softmax(self.vocab_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
self.logits = calculate_final_logits(self.decoder_output_1, self.all_att_weights, self.vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask, vocab_size,
self.tiled_len) # [b * l_t, v + v']
self.pred_ids = tf.reshape(tf.argmax(self.logits, axis=-1), [self.batch_size, -1]) # [b, l_t]
self.out_embed = dec_output
self.masked_out_embed = self.out_embed * tf.expand_dims(self.output_mask, -1)
self.decoder_input = tf.pad(self.masked_out_embed, [[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
# ################################################### decoding train - 2
self.second_dec_attn_bias = attention_bias(tf.shape(self.masked_out_embed)[1], 'cloze_bias')
self.all_att_weights, self.decoder_output_2 = transformer_decoder(self.decoder_input, self.encoder_output,
self.second_dec_attn_bias,
self.enc_attn_bias,
self.hps, scope='t_decoder', reuse=True)
# [b, l_t, e] => [b*l_t, v]
self.decoder_output_2 = tf.reshape(self.decoder_output_2, [-1, hidden_size])
self.second_logits = tf.matmul(self.decoder_output_2, self.decoder_weights, False, True) # (b*l_t, v)
self.vocab_probs_2 = tf.nn.softmax(self.second_logits) # [b * l_t, v]
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
self.second_logits = calculate_final_logits(self.decoder_output_2, self.all_att_weights,
self.vocab_probs_2,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size,
self.tiled_len) # [b * l_t, v + v']
# ################################################### decoding train - 3
# self.all_att_weights, self.decoder_output_3 = transformer_decoder(self.decoder_input, self.encoder_output,
# self.sent_level_attn_bias,
# self.enc_attn_bias,
# self.hps, scope='t_decoder', reuse=True)
# # [b, l_t, e] => [b*l_t, v]
# self.decoder_output_3 = tf.reshape(self.decoder_output_3, [-1, hidden_size])
# self.third_logits = tf.matmul(self.decoder_output_3, self.decoder_weights, False, True) # (b*l_t, v)
# self.vocab_probs_3 = tf.nn.softmax(self.third_logits) # [b * l_t, v]
# with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
# self.third_logits = calculate_final_logits(self.decoder_output_3, self.all_att_weights,
# self.vocab_probs_3,
# self.input_ids_oo, self.max_out_oovs, self.input_mask,
# vocab_size,
# self.tiled_len) # [b * l_t, v + v']
with tf.variable_scope('loss'):
self.ce = smooth_cross_entropy(
self.logits,
self.output_label,
self.hps.label_smoothing)
self.ce = tf.reshape(self.ce, tf.shape(self.output_label)) # [b, l_t]
mle_1 = tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1) # [b]
self.first_loss = tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1)
self.first_loss = tf.reduce_mean(self.first_loss) # scalar
self.second_ce = smooth_cross_entropy(
self.second_logits,
self.output_label,
self.hps.label_smoothing)
self.second_ce = tf.reshape(self.second_ce, tf.shape(self.output_label)) # [b, l_t]
output_mask = self.output_mask * keep_the_word
mle_2 = tf.reduce_sum(self.second_ce * output_mask, -1) / (tf.reduce_sum(output_mask, -1) + 0.001) # [b]
self.second_loss = tf.reduce_mean(tf.reduce_sum(self.second_ce * output_mask, -1) / (tf.reduce_sum(
output_mask, -1) + 0.001)) # scalar
# self.ce = smooth_cross_entropy(
# self.third_logits,
# self.output_ids,
# self.hps.label_smoothing)
#
# self.ce = tf.reshape(self.ce, tf.shape(self.output_label)) # [b, l_t]
#
# mle_3 = tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1) # [b]
#
# self.third_loss = tf.reduce_mean(tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(
# self.output_mask, -1)) # scalar
mle = mle_1 + mle_2
self.rl_loss = tf.reduce_mean(mle * self.reward) # scalar
self.ml_loss = self.first_loss + self.second_loss
self.loss = self.hps.rl_lambda * self.rl_loss + (1 - self.hps.rl_lambda) * self.ml_loss
tf.summary.scalar('first_loss', self.first_loss)
tf.summary.scalar('second_loss', self.second_loss)
# tf.summary.scalar('third_loss', self.third_loss)
tf.summary.scalar('reward', tf.reduce_mean(self.reward))
tf.summary.scalar('rl_loss', self.rl_loss)
tf.summary.scalar('ml_loss', self.ml_loss)
tf.summary.scalar('loss', self.loss)
def _build_summarization_model(self):
is_training = self.is_training
config = self.bert_config
self._add_placeholders()
'''Creates a classification model.'''
model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=self.input_ids,
input_mask=self.input_mask,
token_type_ids=self.segment_ids,
use_one_hot_embeddings=self.hps.use_tpu) # use_one_hot_embeddings=Flags.tpu ?
encoder_output = model.get_sequence_output() # [b, l_s, h]
self.sentence_rep = tf.expand_dims(model.get_pooled_output(), axis=1) # [b, 1, h]
self.encoder_output = encoder_output
hidden_size = encoder_output.shape[2].value
self.enc_attn_bias = attention_bias(self.input_mask, 'masking')
with tf.variable_scope('bert', reuse=True):
with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# Perform embedding lookup on the target word ids.
(self.out_embed, self.bert_embeddings) = embedding_lookup(
input_ids=self.output_ids,
vocab_size=config.vocab_size,
embedding_size=config.hidden_size,
initializer_range=config.initializer_range,
word_embedding_name='word_embeddings',
use_one_hot_embeddings=False)
# Add positional embeddings and token type embeddings, then layer
# normalize and perform dropout.
self.out_embed = embedding_postprocessor(
input_tensor=self.out_embed,
use_token_type=True,
token_type_ids=self.out_segment_ids,
token_type_vocab_size=config.type_vocab_size,
token_type_embedding_name='token_type_embeddings',
use_position_embeddings=True,
position_embedding_name='position_embeddings',
initializer_range=config.initializer_range,
max_position_embeddings=config.max_position_embeddings,
dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decoder'):
self.decoder_weights = self.bert_embeddings
self.masked_out_embed = self.out_embed * tf.expand_dims(self.output_mask, -1)
self.decoder_input = tf.pad(self.masked_out_embed, [[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
# ################################################### decoding train - 1
self.dec_attn_bias = attention_bias(tf.shape(self.masked_out_embed)[1], 'causal')
self.all_att_weights, self.decoder_output_1 = transformer_decoder(self.decoder_input, self.encoder_output,
self.dec_attn_bias, self.enc_attn_bias,
self.hps, scope='t_decoder')
sentence_rep = tf.tile(self.sentence_rep, [1, tf.shape(self.decoder_output_1)[1], 1]) # [b, l_t, e]
# [b, l_t, e] => [b*l_t, v]
copy_rep_1 = tf.concat([sentence_rep, self.decoder_output_1], axis=-1) # [b, l_t, 2 * e]
self.decoder_output_1 = tf.reshape(self.decoder_output_1, [-1, hidden_size])
self.vocab_logits = tf.matmul(self.decoder_output_1, self.decoder_weights, False, True) # (b*l_t, v)
self.vocab_probs = tf.nn.softmax(self.vocab_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
copy_rep_1 = tf.reshape(copy_rep_1, [-1, hidden_size * 2])
self.logits = calculate_final_logits(copy_rep_1, self.all_att_weights, self.vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask, vocab_size,
self.tiled_len) # [b * l_t, v + v']
self.pred_ids = tf.reshape(tf.argmax(self.logits, axis=-1), [self.batch_size, -1]) # [b, l_t]
# ################################################### decoding train - 2
self.second_dec_attn_bias = attention_bias(tf.shape(self.masked_out_embed)[1], 'cloze_bias')
self.all_att_weights, self.decoder_output_2 = transformer_decoder(self.decoder_input, self.encoder_output,
self.second_dec_attn_bias,
self.enc_attn_bias,
self.hps, scope='t_decoder', reuse=True)
# [b, l_t, e] => [b*l_t, v]
copy_rep_2 = tf.concat([sentence_rep, self.decoder_output_2], axis=-1)
self.decoder_output_2 = tf.reshape(self.decoder_output_2, [-1, hidden_size])
self.second_logits = tf.matmul(self.decoder_output_2, self.decoder_weights, False, True) # (b*l_t, v)
self.vocab_probs_2 = tf.nn.softmax(self.second_logits) # [b * l_t, v]
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
copy_rep_2 = tf.reshape(copy_rep_2, [-1, hidden_size * 2])
self.second_logits = calculate_final_logits(copy_rep_2, self.all_att_weights,
self.vocab_probs_2,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size,
self.tiled_len) # [b * l_t, v + v']
# ################################################### decoding train - 3
self.all_att_weights, self.decoder_output_3 = transformer_decoder(self.decoder_input, self.encoder_output,
self.sent_level_attn_bias,
self.enc_attn_bias,
self.hps, scope='t_decoder', reuse=True)
# [b, l_t, e] => [b*l_t, v]
copy_rep_3 = tf.concat([sentence_rep, self.decoder_output_3], axis=-1)
self.decoder_output_3 = tf.reshape(self.decoder_output_3, [-1, hidden_size])
self.third_logits = tf.matmul(self.decoder_output_3, self.decoder_weights, False, True) # (b*l_t, v)
self.vocab_probs_3 = tf.nn.softmax(self.third_logits) # [b * l_t, v]
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
copy_rep_3 = tf.reshape(copy_rep_3, [-1, hidden_size * 2])
self.third_logits = calculate_final_logits(copy_rep_3, self.all_att_weights,
self.vocab_probs_3,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size,
self.tiled_len) # [b * l_t, v + v']
with tf.variable_scope('loss'):
self.ce = smooth_cross_entropy(
self.logits,
self.output_label,
self.hps.label_smoothing)
self.ce = tf.reshape(self.ce, tf.shape(self.output_label)) # [b, l_t]
mle_1 = tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1) # [b]
self.first_loss = tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1)
self.first_loss = tf.reduce_mean(self.first_loss) # scalar
self.second_ce = smooth_cross_entropy(
self.second_logits,
self.output_label,
self.hps.label_smoothing)
self.second_ce = tf.reshape(self.second_ce, tf.shape(self.output_label)) # [b, l_t]
mle_2 = tf.reduce_sum(self.second_ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1) # [b]
self.second_loss = tf.reduce_mean(tf.reduce_sum(self.second_ce * self.output_mask, -1) / tf.reduce_sum(
self.output_mask, -1)) # scalar
self.ce = smooth_cross_entropy(
self.third_logits,
self.output_ids,
self.hps.label_smoothing)
self.ce = tf.reshape(self.ce, tf.shape(self.output_label)) # [b, l_t]
mle_3 = tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(self.output_mask, -1) # [b]
self.third_loss = tf.reduce_mean(tf.reduce_sum(self.ce * self.output_mask, -1) / tf.reduce_sum(
self.output_mask, -1)) # scalar
mle = mle_1 + mle_2 + mle_3
self.rl_loss = tf.reduce_mean(mle * self.reward) # scalar
self.ml_loss = self.first_loss + self.second_loss + self.third_loss
self.loss = self.hps.rl_lambda * self.rl_loss + (1 - self.hps.rl_lambda) * self.ml_loss
tf.summary.scalar('first_loss', self.first_loss)
tf.summary.scalar('second_loss', self.second_loss)
tf.summary.scalar('third_loss', self.third_loss)
tf.summary.scalar('reward', tf.reduce_mean(self.reward))
tf.summary.scalar('rl_loss', self.rl_loss)
tf.summary.scalar('ml_loss', self.ml_loss)
tf.summary.scalar('loss', self.loss)
def decode_infer_2(self):
# stage 2, word level inference using decoded sequence
# l_t = decode sequence length
# during infer, following graph are constructed using beam search
hidden_size = self.bert_config.hidden_size
with self.graph.as_default():
target_sequence = tf.squeeze(self.decode_seq, axis=1)
target_sequence = self.trunct(target_sequence)
target_length = self.decode_length
target_seg_ids = tf.zeros_like(target_sequence,
dtype=tf.int32,
name='target_seg_ids_infer_2')
tgt_mask = tf.sequence_mask(target_length,
maxlen=tf.shape(target_sequence)[1],
dtype=tf.float32) # [b, q']
is_training = self.is_training
dec_model = modeling.BertModel(
config=self.bert_config,
is_training=is_training,
input_ids=target_sequence,
input_mask=tgt_mask,
token_type_ids=target_seg_ids,
scope='bert',
reuse=tf.AUTO_REUSE,
use_one_hot_embeddings=self.hps.use_tpu
) # use_one_hot_embeddings=Flags.tpu ?
dec_output = dec_model.get_sequence_output() # [b, l_t, h]
tgt_embed = dec_output
# with tf.variable_scope('bert', reuse=True):
# with tf.variable_scope('embeddings'), tf.device('/cpu:0'):
# # Perform embedding lookup on the target word ids.
# (tgt_embed, _) = embedding_lookup(
# input_ids=target_sequence,
# vocab_size=config.vocab_size,
# embedding_size=config.hidden_size,
# initializer_range=config.initializer_range,
# word_embedding_name='word_embeddings',
# use_one_hot_embeddings=False)
#
# # Add positional embeddings and token type embeddings, then layer
# # normalize and perform dropout.
# tgt_embed = embedding_postprocessor(
# input_tensor=tgt_embed,
# use_token_type=True,
# token_type_ids=target_seg_ids,
# token_type_vocab_size=config.type_vocab_size,
# token_type_embedding_name='token_type_embeddings',
# use_position_embeddings=True,
# position_embedding_name='position_embeddings',
# initializer_range=config.initializer_range,
# max_position_embeddings=config.max_position_embeddings,
# dropout_prob=config.hidden_dropout_prob)
with tf.variable_scope('decoder_2', reuse=True):
masked_tgt_embed = tgt_embed * tf.expand_dims(tgt_mask, -1)
second_dec_attn_bias = attention_bias(
tf.shape(masked_tgt_embed)[1], 'cloze_bias')
infer_decoder_input = tf.pad(
masked_tgt_embed,
[[0, 0], [1, 0], [0, 0]])[:, :-1, :] # Shift left
all_att_weights, decoder_output = transformer_decoder(
infer_decoder_input,
self.enc_output,
second_dec_attn_bias,
self.enc_attn_bias,
self.hps,
scope='decoder_2')
# [b, l_t, e] => [b*l_t, v]
decoder_output = tf.reshape(decoder_output, [-1, hidden_size])
second_logits = tf.matmul(decoder_output, self.decoder_weights,
False, True) # (b*l_t, v)
vocab_probs = tf.nn.softmax(second_logits) # [b * l_t, v]
vocab_size = len(self.hps.vocab)
with tf.variable_scope('copy', reuse=tf.AUTO_REUSE):
logits = calculate_final_logits(
decoder_output, all_att_weights, vocab_probs,
self.input_ids_oo, self.max_out_oovs, self.input_mask,
vocab_size, self.infer_tiled_len) # [b * l_t, v + v']
second_log_prob = tf.log(logits)
# (b, l_t, v)
extend_vocab_size = tf.add(tf.constant(vocab_size),
self.max_out_oovs)
second_log_prob = tf.reshape(
second_log_prob,
[-1, tf.shape(target_sequence)[1], extend_vocab_size])
second_log_id = tf.argmax(second_log_prob, axis=-1) # (b, l_t)
return second_log_id