def check_vocab(vocab_file, out_dir, check_special_token=True, sos=None,
eos=None, unk=None):
"""Check if vocab_file doesn't exist, create from corpus_file."""
if tf.gfile.Exists(vocab_file):
utils.print_out("# Vocab file %s exists" % vocab_file)
vocab, vocab_size = load_vocab(vocab_file)
if check_special_token:
# Verify if the vocab starts with unk, sos, eos
# If not, prepend those tokens & generate a new vocab file
if not unk: unk = UNK
if not sos: sos = SOS
if not eos: eos = EOS
assert len(vocab) >= 3
if vocab[0] != unk or vocab[1] != sos or vocab[2] != eos:
utils.print_out("The first 3 vocab words [%s, %s, %s]"
" are not [%s, %s, %s]" %
(vocab[0], vocab[1], vocab[2], unk, sos, eos))
vocab = [unk, sos, eos] + vocab
vocab_size += 3
new_vocab_file = os.path.join(out_dir, os.path.basename(vocab_file))
with codecs.getwriter("utf-8")(
tf.gfile.GFile(new_vocab_file, "wb")) as f:
for word in vocab:
f.write("%s\n" % word)
vocab_file = new_vocab_file
else:
raise ValueError("vocab_file '%s' does not exist." % vocab_file)
vocab_size = len(vocab)
return vocab_size, vocab_file
def load_model(model, ckpt, session, name):
start_time = time.time()
model.saver.restore(session, ckpt)
session.run(tf.tables_initializer())
utils.print_out(" loaded %s model parameters from %s, time %.2fs" %
(name, ckpt, time.time() - start_time))
return model
def _cell_list(unit_type,
num_units,
num_layers,
num_residual_layers,
forget_bias,
dropout,
mode,
num_gpus,
base_gpu=0,
single_cell_fn=None,
residual_fn=None):
"""Create a list of RNN cells."""
if not single_cell_fn:
single_cell_fn = _single_cell
# Multi-GPU
cell_list = []
for i in range(num_layers):
utils.print_out(" cell %d" % i, new_line=False)
single_cell = single_cell_fn(
unit_type=unit_type,
num_units=num_units,
forget_bias=forget_bias,
dropout=dropout,
mode=mode,
residual_connection=(i >= num_layers - num_residual_layers),
device_str=get_device_str(i + base_gpu, num_gpus),
residual_fn=residual_fn)
utils.print_out("")
cell_list.append(single_cell)
return cell_list
def print_step_info(prefix, global_step, info, result_summary, log_f):
"""Print all info at the current global step."""
utils.print_out(
"%sstep %d lr %g step-time %.2fs wps %.2fK ppl %.2f gN %.2f %s, %s" %
(prefix, global_step, info["learning_rate"], info["avg_step_time"],
info["speed"], info["train_ppl"], info["avg_grad_norm"],
result_summary, time.ctime()), log_f)
def _external_eval(model,
global_step,
sess,
hparams,
iterator,
iterator_feed_dict,
tgt_file,
label,
summary_writer,
save_on_best,
avg_ckpts=False):
"""External evaluation such as BLEU and ROUGE scores."""
out_dir = hparams.out_dir
decode = global_step > 0
if avg_ckpts:
label = "avg_" + label
if decode:
utils.print_out("# External evaluation, global step %d" % global_step)
sess.run(iterator.initializer, feed_dict=iterator_feed_dict)
output = os.path.join(out_dir, "output_%s" % label)
scores = nmt_utils.decode_and_evaluate(
label,
model,
sess,
output,
ref_file=tgt_file,
metrics=hparams.metrics,
subword_option=hparams.subword_option,
beam_width=hparams.beam_width,
tgt_eos=hparams.eos,
decode=decode)
# Save on best metrics
if decode:
for metric in hparams.metrics:
if avg_ckpts:
best_metric_label = "avg_best_" + metric
else:
best_metric_label = "best_" + metric
utils.add_summary(summary_writer, global_step,
"%s_%s" % (label, metric), scores[metric])
# metric: larger is better
if save_on_best and scores[metric] > getattr(
hparams, best_metric_label):
setattr(hparams, best_metric_label, scores[metric])
model.saver.save(sess,
os.path.join(
getattr(hparams,
best_metric_label + "_dir"),
"translate.ckpt"),
global_step=model.global_step)
utils.save_hparams(out_dir, hparams)
return scores
def _sample_decode(model, global_step, sess, hparams, iterator, src_data,
tgt_data, iterator_src_placeholder,
iterator_batch_size_placeholder, summary_writer):
"""Pick a sentence and decode."""
decode_id = random.randint(0, len(src_data) - 1)
utils.print_out(" # %d" % decode_id)
iterator_feed_dict = {
iterator_src_placeholder: [src_data[decode_id]],
iterator_batch_size_placeholder: 1,
}
sess.run(iterator.initializer, feed_dict=iterator_feed_dict)
nmt_outputs, attention_summary = model.decode(sess)
if hparams.beam_width > 0:
# get the top translation.
nmt_outputs = nmt_outputs[0]
translation = nmt_utils.get_translation(
nmt_outputs,
sent_id=0,
tgt_eos=hparams.eos,
subword_option=hparams.subword_option)
utils.print_out(" src: %s" % src_data[decode_id])
utils.print_out(" ref: %s" % tgt_data[decode_id])
utils.print_out(b" nmt: " + translation)
# Summary
if attention_summary is not None:
summary_writer.add_summary(attention_summary, global_step)
def create_or_load_model(model, model_dir, session, name):
"""Create translation model and initialize or load parameters in session."""
latest_ckpt = tf.train.latest_checkpoint(model_dir)
if latest_ckpt:
model = load_model(model, latest_ckpt, session, name)
else:
start_time = time.time()
session.run(tf.global_variables_initializer())
session.run(tf.tables_initializer())
utils.print_out(
" created %s model with fresh parameters, time %.2fs" %
(name, time.time() - start_time))
global_step = model.global_step.eval(session=session)
return model, global_step
def process_stats(stats, info, global_step, steps_per_stats, log_f):
"""Update info and check for overflow."""
# Update info
info["avg_step_time"] = stats["step_time"] / steps_per_stats
info["avg_grad_norm"] = stats["grad_norm"] / steps_per_stats
info["train_ppl"] = utils.safe_exp(stats["loss"] / stats["predict_count"])
info["speed"] = stats["total_count"] / (1000 * stats["step_time"])
# Check for overflow
is_overflow = False
train_ppl = info["train_ppl"]
if math.isnan(train_ppl) or math.isinf(train_ppl) or train_ppl > 1e20:
utils.print_out(" step %d overflow, stop early" % global_step, log_f)
is_overflow = True
return is_overflow
def single_worker_inference(infer_model, ckpt, inference_input_file,
inference_output_file, hparams):
"""Inference with a single worker."""
output_infer = inference_output_file
# Read data
infer_data = load_data(inference_input_file, hparams)
with tf.Session(graph=infer_model.graph,
config=utils.get_config_proto()) as sess:
loaded_infer_model = model_helper.load_model(infer_model.model, ckpt,
sess, "infer")
sess.run(infer_model.iterator.initializer,
feed_dict={
infer_model.src_placeholder: infer_data,
infer_model.batch_size_placeholder:
hparams.infer_batch_size
})
# Decode
utils.print_out("# Start decoding")
if hparams.inference_indices:
_decode_inference_indices(
loaded_infer_model,
sess,
output_infer=output_infer,
output_infer_summary_prefix=output_infer,
inference_indices=hparams.inference_indices,
tgt_eos=hparams.eos,
subword_option=hparams.subword_option)
else:
nmt_utils.decode_and_evaluate(
"infer",
loaded_infer_model,
sess,
output_infer,
ref_file=None,
metrics=hparams.metrics,
subword_option=hparams.subword_option,
beam_width=hparams.beam_width,
tgt_eos=hparams.eos,
num_translations_per_input=hparams.num_translations_per_input)
def _create_pretrained_emb_from_txt(vocab_file,
embed_file,
num_trainable_tokens=3,
dtype=tf.float32,
scope=None):
"""Load pretrain embeding from embed_file, and return an embedding matrix.
Args:
embed_file: Path to a Glove formated embedding txt file.
num_trainable_tokens: Make the first n tokens in the vocab file as trainable
variables. Default is 3, which is "<unk>", "<s>" and "</s>".
"""
vocab, _ = vocab_utils.load_vocab(vocab_file)
trainable_tokens = vocab[:num_trainable_tokens]
utils.print_out("# Using pretrained embedding: %s." % embed_file)
utils.print_out(" with trainable tokens: ")
emb_dict, emb_size = vocab_utils.load_embed_txt(embed_file)
for token in trainable_tokens:
utils.print_out(" %s" % token)
if token not in emb_dict:
emb_dict[token] = [0.0] * emb_size
emb_mat = np.array([emb_dict[token] for token in vocab],
dtype=dtype.as_numpy_dtype())
emb_mat = tf.constant(emb_mat)
emb_mat_const = tf.slice(emb_mat, [num_trainable_tokens, 0], [-1, -1])
with tf.variable_scope(scope or "pretrain_embeddings",
dtype=dtype) as scope:
with tf.device(_get_embed_device(num_trainable_tokens)):
emb_mat_var = tf.get_variable("emb_mat_var",
[num_trainable_tokens, emb_size])
return tf.concat([emb_mat_var, emb_mat_const], 0)
def _decode_inference_indices(model, sess, output_infer,
output_infer_summary_prefix, inference_indices,
tgt_eos, subword_option):
"""Decoding only a specific set of sentences."""
utils.print_out(" decoding to output %s , num sents %d." %
(output_infer, len(inference_indices)))
start_time = time.time()
with codecs.getwriter("utf-8")(tf.gfile.GFile(output_infer,
mode="wb")) as trans_f:
trans_f.write("") # Write empty string to ensure file is created.
for decode_id in inference_indices:
nmt_outputs, infer_summary = model.decode(sess)
# get text translation
assert nmt_outputs.shape[0] == 1
translation = nmt_utils.get_translation(
nmt_outputs,
sent_id=0,
tgt_eos=tgt_eos,
subword_option=subword_option)
if infer_summary is not None: # Attention models
image_file = output_infer_summary_prefix + str(
decode_id) + ".png"
utils.print_out(" save attention image to %s*" % image_file)
image_summ = tf.Summary()
image_summ.ParseFromString(infer_summary)
with tf.gfile.GFile(image_file, mode="w") as img_f:
img_f.write(image_summ.value[0].image.encoded_image_string)
trans_f.write("%s\n" % translation)
utils.print_out(translation + b"\n")
utils.print_time(" done", start_time)
def ensure_compatible_hparams(hparams, default_hparams, hparams_path):
"""Make sure the loaded hparams is compatible with new changes."""
default_hparams = utils.maybe_parse_standard_hparams(
default_hparams, hparams_path)
# For compatible reason, if there are new fields in default_hparams,
# we add them to the current hparams
default_config = default_hparams.values()
config = hparams.values()
for key in default_config:
if key not in config:
hparams.add_hparam(key, default_config[key])
# Update all hparams' keys if override_loaded_hparams=True
if default_hparams.override_loaded_hparams:
for key in default_config:
if getattr(hparams, key) != default_config[key]:
utils.print_out("# Updating hparams.%s: %s -> %s" %
(key, str(getattr(
hparams, key)), str(default_config[key])))
setattr(hparams, key, default_config[key])
return hparams
def before_train(loaded_train_model, train_model, train_sess, global_step,
hparams, log_f):
"""Misc tasks to do before training."""
stats = init_stats()
info = {
"train_ppl": 0.0,
"speed": 0.0,
"avg_step_time": 0.0,
"avg_grad_norm": 0.0,
"learning_rate":
loaded_train_model.learning_rate.eval(session=train_sess)
}
start_train_time = time.time()
utils.print_out(
"# Start step %d, lr %g, %s" %
(global_step, info["learning_rate"], time.ctime()), log_f)
# Initialize all of the iterators
skip_count = hparams.batch_size * hparams.epoch_step
utils.print_out("# Init train iterator, skipping %d elements" % skip_count)
train_sess.run(train_model.iterator.initializer,
feed_dict={train_model.skip_count_placeholder: skip_count})
return stats, info, start_train_time
def run_main(flags,
default_hparams,
train_fn,
inference_fn,
target_session=""):
"""Run main."""
# Job
jobid = flags.jobid
num_workers = flags.num_workers
utils.print_out("# Job id %d" % jobid)
# Random
random_seed = flags.random_seed
if random_seed is not None and random_seed > 0:
utils.print_out("# Set random seed to %d" % random_seed)
random.seed(random_seed + jobid)
np.random.seed(random_seed + jobid)
## Train / Decode
out_dir = flags.out_dir
if not tf.gfile.Exists(out_dir): tf.gfile.MakeDirs(out_dir)
# Load hparams.如果有新写入的参数需要重新写进去，并缓存在本地
hparams = create_or_load_hparams(out_dir,
default_hparams,
flags.hparams_path,
save_hparams=(jobid == 0))
if flags.inference_input_file:
# Inference indices
hparams.inference_indices = None
if flags.inference_list:
(hparams.inference_indices) = ([
int(token) for token in flags.inference_list.split(",")
])
# Inference
trans_file = flags.inference_output_file
ckpt = flags.ckpt
if not ckpt:
ckpt = tf.train.latest_checkpoint(out_dir)
inference_fn(ckpt, flags.inference_input_file, trans_file, hparams,
num_workers, jobid)
# Evaluation
ref_file = flags.inference_ref_file
if ref_file and tf.gfile.Exists(trans_file):
for metric in hparams.metrics:
score = evaluation_utils.evaluate(ref_file, trans_file, metric,
hparams.subword_option)
utils.print_out(" %s: %.1f" % (metric, score))
else:
# Train
train_fn(hparams, target_session=target_session)
def _build_encoder(self, hparams):
"""Build a GNMT encoder."""
if hparams.encoder_type == "uni" or hparams.encoder_type == "bi":
return super(GNMTModel, self)._build_encoder(hparams)
if hparams.encoder_type != "gnmt":
raise ValueError("Unknown encoder_type %s" % hparams.encoder_type)
# Build GNMT encoder.
num_bi_layers = 1
num_uni_layers = self.num_encoder_layers - num_bi_layers
utils.print_out(" num_bi_layers = %d" % num_bi_layers)
utils.print_out(" num_uni_layers = %d" % num_uni_layers)
iterator = self.iterator
source = iterator.source
if self.time_major:
source = tf.transpose(source)
with tf.variable_scope("encoder") as scope:
dtype = scope.dtype
# Look up embedding, emp_inp: [max_time, batch_size, num_units]
# when time_major = True
encoder_emb_inp = tf.nn.embedding_lookup(self.embedding_encoder,
source)
# Execute _build_bidirectional_rnn from Model class
bi_encoder_outputs, bi_encoder_state = self._build_bidirectional_rnn(
inputs=encoder_emb_inp,
sequence_length=iterator.source_sequence_length,
dtype=dtype,
hparams=hparams,
num_bi_layers=num_bi_layers,
num_bi_residual_layers=0, # no residual connection
)
uni_cell = model_helper.create_rnn_cell(
unit_type=hparams.unit_type,
num_units=hparams.num_units,
num_layers=num_uni_layers,
num_residual_layers=self.num_encoder_residual_layers,
forget_bias=hparams.forget_bias,
dropout=hparams.dropout,
num_gpus=self.num_gpus,
base_gpu=1,
mode=self.mode,
single_cell_fn=self.single_cell_fn)
# encoder_outputs: size [max_time, batch_size, num_units]
# when time_major = True
encoder_outputs, encoder_state = tf.nn.dynamic_rnn(
uni_cell,
bi_encoder_outputs,
dtype=dtype,
sequence_length=iterator.source_sequence_length,
time_major=self.time_major)
# Pass all encoder state except the first bi-directional layer's state to
# decoder.
encoder_state = (bi_encoder_state[1], ) + (
(encoder_state, ) if num_uni_layers == 1 else encoder_state)
return encoder_outputs, encoder_state
def decode_and_evaluate(name,
model,
sess,
trans_file,
ref_file,
metrics,
subword_option,
beam_width,
tgt_eos,
num_translations_per_input=1,
decode=True):
"""Decode a test set and compute a score according to the evaluation task."""
# Decode
if decode:
utils.print_out(" decoding to output %s." % trans_file)
start_time = time.time()
num_sentences = 0
with codecs.getwriter("utf-8")(tf.gfile.GFile(trans_file,
mode="wb")) as trans_f:
trans_f.write("") # Write empty string to ensure file is created.
num_translations_per_input = max(
min(num_translations_per_input, beam_width), 1)
while True:
try:
nmt_outputs, _ = model.decode(sess)
if beam_width == 0:
nmt_outputs = np.expand_dims(nmt_outputs, 0)
batch_size = nmt_outputs.shape[1]
num_sentences += batch_size
for sent_id in range(batch_size):
for beam_id in range(num_translations_per_input):
translation = get_translation(
nmt_outputs[beam_id],
sent_id,
tgt_eos=tgt_eos,
subword_option=subword_option)
trans_f.write(
(translation + b"\n").decode("utf-8"))
except tf.errors.OutOfRangeError:
utils.print_time(
" done, num sentences %d, num translations per input %d"
% (num_sentences, num_translations_per_input),
start_time)
break
# Evaluation
evaluation_scores = {}
if ref_file and tf.gfile.Exists(trans_file):
for metric in metrics:
score = evaluation_utils.evaluate(ref_file,
trans_file,
metric,
subword_option=subword_option)
evaluation_scores[metric] = score
utils.print_out(" %s %s: %.1f" % (metric, name, score))
return evaluation_scores
def multi_worker_inference(infer_model, ckpt, inference_input_file,
inference_output_file, hparams, num_workers, jobid):
"""Inference using multiple workers."""
assert num_workers > 1
final_output_infer = inference_output_file
output_infer = "%s_%d" % (inference_output_file, jobid)
output_infer_done = "%s_done_%d" % (inference_output_file, jobid)
# Read data
infer_data = load_data(inference_input_file, hparams)
# Split data to multiple workers
total_load = len(infer_data)
load_per_worker = int((total_load - 1) / num_workers) + 1
start_position = jobid * load_per_worker
end_position = min(start_position + load_per_worker, total_load)
infer_data = infer_data[start_position:end_position]
with tf.Session(graph=infer_model.graph,
config=utils.get_config_proto()) as sess:
loaded_infer_model = model_helper.load_model(infer_model.model, ckpt,
sess, "infer")
sess.run(
infer_model.iterator.initializer, {
infer_model.src_placeholder: infer_data,
infer_model.batch_size_placeholder: hparams.infer_batch_size
})
# Decode
utils.print_out("# Start decoding")
nmt_utils.decode_and_evaluate(
"infer",
loaded_infer_model,
sess,
output_infer,
ref_file=None,
metrics=hparams.metrics,
subword_option=hparams.subword_option,
beam_width=hparams.beam_width,
tgt_eos=hparams.eos,
num_translations_per_input=hparams.num_translations_per_input)
# Change file name to indicate the file writing is completed.
tf.gfile.Rename(output_infer, output_infer_done, overwrite=True)
# Job 0 is responsible for the clean up.
if jobid != 0: return
# Now write all translations
with codecs.getwriter("utf-8")(tf.gfile.GFile(final_output_infer,
mode="wb")) as final_f:
for worker_id in range(num_workers):
worker_infer_done = "%s_done_%d" % (inference_output_file,
worker_id)
while not tf.gfile.Exists(worker_infer_done):
utils.print_out(" waitting job %d to complete." %
worker_id)
time.sleep(10)
with codecs.getreader("utf-8")(tf.gfile.GFile(
worker_infer_done, mode="rb")) as f:
for translation in f:
final_f.write("%s" % translation)
for worker_id in range(num_workers):
worker_infer_done = "%s_done_%d" % (inference_output_file,
worker_id)
tf.gfile.Remove(worker_infer_done)
def _single_cell(unit_type,
num_units,
forget_bias,
dropout,
mode,
residual_connection=False,
device_str=None,
residual_fn=None):
"""Create an instance of a single RNN cell."""
# dropout (= 1 - keep_prob) is set to 0 during eval and infer
dropout = dropout if mode == tf.contrib.learn.ModeKeys.TRAIN else 0.0
# Cell Type
if unit_type == "lstm":
utils.print_out(" LSTM, forget_bias=%g" % forget_bias, new_line=False)
single_cell = tf.contrib.rnn.BasicLSTMCell(num_units,
forget_bias=forget_bias)
elif unit_type == "gru":
utils.print_out(" GRU", new_line=False)
single_cell = tf.contrib.rnn.GRUCell(num_units)
elif unit_type == "layer_norm_lstm":
utils.print_out(" Layer Normalized LSTM, forget_bias=%g" %
forget_bias,
new_line=False)
single_cell = tf.contrib.rnn.LayerNormBasicLSTMCell(
num_units, forget_bias=forget_bias, layer_norm=True)
elif unit_type == "nas":
utils.print_out(" NASCell", new_line=False)
single_cell = tf.contrib.rnn.NASCell(num_units)
else:
raise ValueError("Unknown unit type %s!" % unit_type)
# Dropout (= 1 - keep_prob)
if dropout > 0.0:
single_cell = tf.contrib.rnn.DropoutWrapper(cell=single_cell,
input_keep_prob=(1.0 -
dropout))
utils.print_out(" %s, dropout=%g " %
(type(single_cell).__name__, dropout),
new_line=False)
# Residual
if residual_connection:
single_cell = tf.contrib.rnn.ResidualWrapper(single_cell,
residual_fn=residual_fn)
utils.print_out(" %s" % type(single_cell).__name__, new_line=False)
# Device Wrapper
if device_str:
single_cell = tf.contrib.rnn.DeviceWrapper(single_cell, device_str)
utils.print_out(" %s, device=%s" %
(type(single_cell).__name__, device_str),
new_line=False)
return single_cell
def avg_checkpoints(model_dir, num_last_checkpoints, global_step,
global_step_name):
"""Average the last N checkpoints in the model_dir."""
checkpoint_state = tf.train.get_checkpoint_state(model_dir)
if not checkpoint_state:
utils.print_out("# No checkpoint file found in directory: %s" %
model_dir)
return None
# Checkpoints are ordered from oldest to newest.
checkpoints = (
checkpoint_state.all_model_checkpoint_paths[-num_last_checkpoints:])
if len(checkpoints) < num_last_checkpoints:
utils.print_out(
"# Skipping averaging checkpoints because not enough checkpoints is "
"avaliable.")
return None
avg_model_dir = os.path.join(model_dir, "avg_checkpoints")
if not tf.gfile.Exists(avg_model_dir):
utils.print_out(
"# Creating new directory %s for saving averaged checkpoints." %
avg_model_dir)
tf.gfile.MakeDirs(avg_model_dir)
utils.print_out("# Reading and averaging variables in checkpoints:")
var_list = tf.contrib.framework.list_variables(checkpoints[0])
var_values, var_dtypes = {}, {}
for (name, shape) in var_list:
if name != global_step_name:
var_values[name] = np.zeros(shape)
for checkpoint in checkpoints:
utils.print_out(" %s" % checkpoint)
reader = tf.contrib.framework.load_checkpoint(checkpoint)
for name in var_values:
tensor = reader.get_tensor(name)
var_dtypes[name] = tensor.dtype
var_values[name] += tensor
for name in var_values:
var_values[name] /= len(checkpoints)
# Build a graph with same variables in the checkpoints, and save the averaged
# variables into the avg_model_dir.
with tf.Graph().as_default():
tf_vars = [
tf.get_variable(v,
shape=var_values[v].shape,
dtype=var_dtypes[name]) for v in var_values
]
placeholders = [
tf.placeholder(v.dtype, shape=v.shape) for v in tf_vars
]
assign_ops = [tf.assign(v, p) for (v, p) in zip(tf_vars, placeholders)]
global_step_var = tf.Variable(global_step,
name=global_step_name,
trainable=False)
saver = tf.train.Saver(tf.all_variables())
with tf.Session() as sess:
sess.run(tf.initialize_all_variables())
for p, assign_op, (name, value) in zip(placeholders, assign_ops,
six.iteritems(var_values)):
sess.run(assign_op, {p: value})
# Use the built saver to save the averaged checkpoint. Only keep 1
# checkpoint and the best checkpoint will be moved to avg_best_metric_dir.
saver.save(sess, os.path.join(avg_model_dir, "translate.ckpt"))
return avg_model_dir
def extend_hparams(hparams):
"""Extend training hparams."""
assert hparams.num_encoder_layers and hparams.num_decoder_layers
if hparams.num_encoder_layers != hparams.num_decoder_layers:
hparams.pass_hidden_state = False
utils.print_out(
"Num encoder layer %d is different from num decoder layer"
" %d, so set pass_hidden_state to False" %
(hparams.num_encoder_layers, hparams.num_decoder_layers))
# Sanity checks
if hparams.encoder_type == "bi" and hparams.num_encoder_layers % 2 != 0:
raise ValueError("For bi, num_encoder_layers %d should be even" %
hparams.num_encoder_layers)
if (hparams.attention_architecture in ["gnmt"]
and hparams.num_encoder_layers < 2):
raise ValueError("For gnmt attention architecture, "
"num_encoder_layers %d should be >= 2" %
hparams.num_encoder_layers)
# Set residual layers
num_encoder_residual_layers = 0
num_decoder_residual_layers = 0
if hparams.residual:
if hparams.num_encoder_layers > 1:
num_encoder_residual_layers = hparams.num_encoder_layers - 1
if hparams.num_decoder_layers > 1:
num_decoder_residual_layers = hparams.num_decoder_layers - 1
if hparams.encoder_type == "gnmt":
# The first unidirectional layer (after the bi-directional layer) in
# the GNMT encoder can't have residual connection due to the input is
# the concatenation of fw_cell and bw_cell's outputs.
num_encoder_residual_layers = hparams.num_encoder_layers - 2
# Compatible for GNMT models
if hparams.num_encoder_layers == hparams.num_decoder_layers:
num_decoder_residual_layers = num_encoder_residual_layers
hparams.add_hparam("num_encoder_residual_layers",
num_encoder_residual_layers)
hparams.add_hparam("num_decoder_residual_layers",
num_decoder_residual_layers)
if hparams.subword_option and hparams.subword_option not in ["spm", "bpe"]:
raise ValueError("subword option must be either spm, or bpe")
# Flags
utils.print_out("# hparams:")
utils.print_out(" src=%s" % hparams.src)
utils.print_out(" tgt=%s" % hparams.tgt)
utils.print_out(" train_prefix=%s" % hparams.train_prefix)
utils.print_out(" dev_prefix=%s" % hparams.dev_prefix)
utils.print_out(" test_prefix=%s" % hparams.test_prefix)
utils.print_out(" out_dir=%s" % hparams.out_dir)
## Vocab
# Get vocab file names first
if hparams.vocab_prefix:
src_vocab_file = hparams.vocab_prefix + "." + hparams.src
tgt_vocab_file = hparams.vocab_prefix + "." + hparams.tgt
else:
raise ValueError("hparams.vocab_prefix must be provided.")
# Source vocab
src_vocab_size, src_vocab_file = vocab_utils.check_vocab(
src_vocab_file,
hparams.out_dir,
check_special_token=hparams.check_special_token,
sos=hparams.sos,
eos=hparams.eos,
unk=vocab_utils.UNK)
# Target vocab
if hparams.share_vocab:
utils.print_out(" using source vocab for target")
tgt_vocab_file = src_vocab_file
tgt_vocab_size = src_vocab_size
else:
tgt_vocab_size, tgt_vocab_file = vocab_utils.check_vocab(
tgt_vocab_file,
hparams.out_dir,
check_special_token=hparams.check_special_token,
sos=hparams.sos,
eos=hparams.eos,
unk=vocab_utils.UNK)
hparams.add_hparam("src_vocab_size", src_vocab_size)
hparams.add_hparam("tgt_vocab_size", tgt_vocab_size)
hparams.add_hparam("src_vocab_file", src_vocab_file)
hparams.add_hparam("tgt_vocab_file", tgt_vocab_file)
# Pretrained Embeddings:
hparams.add_hparam("src_embed_file", "")
hparams.add_hparam("tgt_embed_file", "")
if hparams.embed_prefix:
src_embed_file = hparams.embed_prefix + "." + hparams.src
tgt_embed_file = hparams.embed_prefix + "." + hparams.tgt
if tf.gfile.Exists(src_embed_file):
hparams.src_embed_file = src_embed_file
if tf.gfile.Exists(tgt_embed_file):
hparams.tgt_embed_file = tgt_embed_file
# Check out_dir
if not tf.gfile.Exists(hparams.out_dir):
utils.print_out("# Creating output directory %s ..." % hparams.out_dir)
tf.gfile.MakeDirs(hparams.out_dir)
# Evaluation
for metric in hparams.metrics:
hparams.add_hparam("best_" + metric, 0) # larger is better
best_metric_dir = os.path.join(hparams.out_dir, "best_" + metric)
hparams.add_hparam("best_" + metric + "_dir", best_metric_dir)
tf.gfile.MakeDirs(best_metric_dir)
if hparams.avg_ckpts:
hparams.add_hparam("avg_best_" + metric, 0) # larger is better
best_metric_dir = os.path.join(hparams.out_dir,
"avg_best_" + metric)
hparams.add_hparam("avg_best_" + metric + "_dir", best_metric_dir)
tf.gfile.MakeDirs(best_metric_dir)
return hparams
def train(hparams, scope=None, target_session=""):
"""Train a translation model."""
log_device_placement = hparams.log_device_placement
out_dir = hparams.out_dir
num_train_steps = hparams.num_train_steps
steps_per_stats = hparams.steps_per_stats
steps_per_external_eval = hparams.steps_per_external_eval
steps_per_eval = 10 * steps_per_stats
avg_ckpts = hparams.avg_ckpts
if not steps_per_external_eval:
steps_per_external_eval = 5 * steps_per_eval
if not hparams.attention:
model_creator = nmt_model.Model
else: # Attention
if (hparams.encoder_type == "gnmt"
or hparams.attention_architecture in ["gnmt", "gnmt_v2"]):
model_creator = gnmt_model.GNMTModel
elif hparams.attention_architecture == "standard":
model_creator = attention_model.AttentionModel
else:
raise ValueError("Unknown attention architecture %s" %
hparams.attention_architecture)
train_model = model_helper.create_train_model(model_creator, hparams,
scope)
eval_model = model_helper.create_eval_model(model_creator, hparams, scope)
infer_model = model_helper.create_infer_model(model_creator, hparams,
scope)
# Preload data for sample decoding.
dev_src_file = "%s.%s" % (hparams.dev_prefix, hparams.src)
dev_tgt_file = "%s.%s" % (hparams.dev_prefix, hparams.tgt)
sample_src_data = inference.load_data(dev_src_file)
sample_tgt_data = inference.load_data(dev_tgt_file)
summary_name = "train_log"
model_dir = hparams.out_dir
# Log and output files
log_file = os.path.join(out_dir, "log_%d" % time.time())
log_f = tf.gfile.GFile(log_file, mode="a")
utils.print_out("# log_file=%s" % log_file, log_f)
# TensorFlow model
config_proto = utils.get_config_proto(
log_device_placement=log_device_placement,
num_intra_threads=hparams.num_intra_threads,
num_inter_threads=hparams.num_inter_threads)
train_sess = tf.Session(target=target_session,
config=config_proto,
graph=train_model.graph)
eval_sess = tf.Session(target=target_session,
config=config_proto,
graph=eval_model.graph)
infer_sess = tf.Session(target=target_session,
config=config_proto,
graph=infer_model.graph)
with train_model.graph.as_default():
loaded_train_model, global_step = model_helper.create_or_load_model(
train_model.model, model_dir, train_sess, "train")
# Summary writer
summary_writer = tf.summary.FileWriter(os.path.join(out_dir, summary_name),
train_model.graph)
# First evaluation
run_full_eval(model_dir, infer_model, infer_sess, eval_model, eval_sess,
hparams, summary_writer, sample_src_data, sample_tgt_data,
avg_ckpts)
last_stats_step = global_step
last_eval_step = global_step
last_external_eval_step = global_step
# This is the training loop.
stats, info, start_train_time = before_train(loaded_train_model,
train_model, train_sess,
global_step, hparams, log_f)
while global_step < num_train_steps:
### Run a step ###
start_time = time.time()
try:
step_result = loaded_train_model.train(train_sess)
hparams.epoch_step += 1
except tf.errors.OutOfRangeError:
# Finished going through the training dataset. Go to next epoch.
hparams.epoch_step = 0
utils.print_out(
"# Finished an epoch, step %d. Perform external evaluation" %
global_step)
run_sample_decode(infer_model, infer_sess, model_dir, hparams,
summary_writer, sample_src_data, sample_tgt_data)
run_external_eval(infer_model, infer_sess, model_dir, hparams,
summary_writer)
if avg_ckpts:
run_avg_external_eval(infer_model, infer_sess, model_dir,
hparams, summary_writer, global_step)
train_sess.run(train_model.iterator.initializer,
feed_dict={train_model.skip_count_placeholder: 0})
continue
# Process step_result, accumulate stats, and write summary
global_step, info["learning_rate"], step_summary = update_stats(
stats, start_time, step_result)
summary_writer.add_summary(step_summary, global_step)
# Once in a while, we print statistics.
if global_step - last_stats_step >= steps_per_stats:
last_stats_step = global_step
is_overflow = process_stats(stats, info, global_step,
steps_per_stats, log_f)
print_step_info(" ", global_step, info,
_get_best_results(hparams), log_f)
if is_overflow:
break
# Reset statistics
stats = init_stats()
if global_step - last_eval_step >= steps_per_eval:
last_eval_step = global_step
utils.print_out("# Save eval, global step %d" % global_step)
utils.add_summary(summary_writer, global_step, "train_ppl",
info["train_ppl"])
# Save checkpoint
loaded_train_model.saver.save(train_sess,
os.path.join(out_dir,
"translate.ckpt"),
global_step=global_step)
# Evaluate on dev/test
run_sample_decode(infer_model, infer_sess, model_dir, hparams,
summary_writer, sample_src_data, sample_tgt_data)
run_internal_eval(eval_model, eval_sess, model_dir, hparams,
summary_writer)
if global_step - last_external_eval_step >= steps_per_external_eval:
last_external_eval_step = global_step
# Save checkpoint
loaded_train_model.saver.save(train_sess,
os.path.join(out_dir,
"translate.ckpt"),
global_step=global_step)
run_sample_decode(infer_model, infer_sess, model_dir, hparams,
summary_writer, sample_src_data, sample_tgt_data)
run_external_eval(infer_model, infer_sess, model_dir, hparams,
summary_writer)
if avg_ckpts:
run_avg_external_eval(infer_model, infer_sess, model_dir,
hparams, summary_writer, global_step)
# Done training
loaded_train_model.saver.save(train_sess,
os.path.join(out_dir, "translate.ckpt"),
global_step=global_step)
(result_summary, _, final_eval_metrics) = (run_full_eval(
model_dir, infer_model, infer_sess, eval_model, eval_sess, hparams,
summary_writer, sample_src_data, sample_tgt_data, avg_ckpts))
print_step_info("# Final, ", global_step, info, result_summary, log_f)
utils.print_time("# Done training!", start_train_time)
summary_writer.close()
utils.print_out("# Start evaluating saved best models.")
for metric in hparams.metrics:
best_model_dir = getattr(hparams, "best_" + metric + "_dir")
summary_writer = tf.summary.FileWriter(
os.path.join(best_model_dir, summary_name), infer_model.graph)
result_summary, best_global_step, _ = run_full_eval(
best_model_dir, infer_model, infer_sess, eval_model, eval_sess,
hparams, summary_writer, sample_src_data, sample_tgt_data)
print_step_info("# Best %s, " % metric, best_global_step, info,
result_summary, log_f)
summary_writer.close()
if avg_ckpts:
best_model_dir = getattr(hparams, "avg_best_" + metric + "_dir")
summary_writer = tf.summary.FileWriter(
os.path.join(best_model_dir, summary_name), infer_model.graph)
result_summary, best_global_step, _ = run_full_eval(
best_model_dir, infer_model, infer_sess, eval_model, eval_sess,
hparams, summary_writer, sample_src_data, sample_tgt_data)
print_step_info("# Averaged Best %s, " % metric, best_global_step,
info, result_summary, log_f)
summary_writer.close()
return final_eval_metrics, global_step
def create_emb_for_encoder_and_decoder(share_vocab,
src_vocab_size,
tgt_vocab_size,
src_embed_size,
tgt_embed_size,
dtype=tf.float32,
num_partitions=0,
src_vocab_file=None,
tgt_vocab_file=None,
src_embed_file=None,
tgt_embed_file=None,
scope=None):
"""Create embedding matrix for both encoder and decoder.
Args:
share_vocab: A boolean. Whether to share embedding matrix for both
encoder and decoder.
src_vocab_size: An integer. The source vocab size.
tgt_vocab_size: An integer. The target vocab size.
src_embed_size: An integer. The embedding dimension for the encoder's
embedding.
tgt_embed_size: An integer. The embedding dimension for the decoder's
embedding.
dtype: dtype of the embedding matrix. Default to float32.
num_partitions: number of partitions used for the embedding vars.
scope: VariableScope for the created subgraph. Default to "embedding".
Returns:
embedding_encoder: Encoder's embedding matrix.
embedding_decoder: Decoder's embedding matrix.
Raises:
ValueError: if use share_vocab but source and target have different vocab
size.
"""
if num_partitions <= 1:
partitioner = None
else:
# Note: num_partitions > 1 is required for distributed training due to
# embedding_lookup tries to colocate single partition-ed embedding variable
# with lookup ops. This may cause embedding variables being placed on worker
# jobs.
partitioner = tf.fixed_size_partitioner(num_partitions)
if (src_embed_file or tgt_embed_file) and partitioner:
raise ValueError(
"Can't set num_partitions > 1 when using pretrained embedding")
with tf.variable_scope(scope or "embeddings",
dtype=dtype,
partitioner=partitioner) as scope:
# Share embedding
if share_vocab:
if src_vocab_size != tgt_vocab_size:
raise ValueError(
"Share embedding but different src/tgt vocab sizes"
" %d vs. %d" % (src_vocab_size, tgt_vocab_size))
assert src_embed_size == tgt_embed_size
utils.print_out("# Use the same embedding for source and target")
vocab_file = src_vocab_file or tgt_vocab_file
embed_file = src_embed_file or tgt_embed_file
embedding_encoder = _create_or_load_embed("embedding_share",
vocab_file, embed_file,
src_vocab_size,
src_embed_size, dtype)
embedding_decoder = embedding_encoder
else:
with tf.variable_scope("encoder", partitioner=partitioner):
embedding_encoder = _create_or_load_embed(
"embedding_encoder", src_vocab_file, src_embed_file,
src_vocab_size, src_embed_size, dtype)
with tf.variable_scope("decoder", partitioner=partitioner):
embedding_decoder = _create_or_load_embed(
"embedding_decoder", tgt_vocab_file, tgt_embed_file,
tgt_vocab_size, tgt_embed_size, dtype)
return embedding_encoder, embedding_decoder
