Spaces:
Sleeping
Sleeping
# Copyright 2023 The TensorFlow Authors. All Rights Reserved. | |
# | |
# Licensed under the Apache License, Version 2.0 (the "License"); | |
# you may not use this file except in compliance with the License. | |
# You may obtain a copy of the License at | |
# | |
# http://www.apache.org/licenses/LICENSE-2.0 | |
# | |
# Unless required by applicable law or agreed to in writing, software | |
# distributed under the License is distributed on an "AS IS" BASIS, | |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
# See the License for the specific language governing permissions and | |
# limitations under the License. | |
"""Utilities to save models.""" | |
import os | |
import typing | |
from absl import logging | |
import tensorflow as tf, tf_keras | |
def export_bert_model(model_export_path: typing.Text, | |
model: tf_keras.Model, | |
checkpoint_dir: typing.Optional[typing.Text] = None, | |
restore_model_using_load_weights: bool = False) -> None: | |
"""Export BERT model for serving which does not include the optimizer. | |
Args: | |
model_export_path: Path to which exported model will be saved. | |
model: Keras model object to export. | |
checkpoint_dir: Path from which model weights will be loaded, if | |
specified. | |
restore_model_using_load_weights: Whether to use checkpoint.restore() API | |
for custom checkpoint or to use model.load_weights() API. There are 2 | |
different ways to save checkpoints. One is using tf.train.Checkpoint and | |
another is using Keras model.save_weights(). Custom training loop | |
implementation uses tf.train.Checkpoint API and Keras ModelCheckpoint | |
callback internally uses model.save_weights() API. Since these two API's | |
cannot be used toghether, model loading logic must be take into account | |
how model checkpoint was saved. | |
Raises: | |
ValueError when either model_export_path or model is not specified. | |
""" | |
if not model_export_path: | |
raise ValueError('model_export_path must be specified.') | |
if not isinstance(model, tf_keras.Model): | |
raise ValueError('model must be a tf_keras.Model object.') | |
if checkpoint_dir: | |
if restore_model_using_load_weights: | |
model_weight_path = os.path.join(checkpoint_dir, 'checkpoint') | |
assert tf.io.gfile.exists(model_weight_path) | |
model.load_weights(model_weight_path) | |
else: | |
checkpoint = tf.train.Checkpoint(model=model) | |
# Restores the model from latest checkpoint. | |
latest_checkpoint_file = tf.train.latest_checkpoint(checkpoint_dir) | |
assert latest_checkpoint_file | |
logging.info('Checkpoint file %s found and restoring from ' | |
'checkpoint', latest_checkpoint_file) | |
checkpoint.restore( | |
latest_checkpoint_file).assert_existing_objects_matched() | |
model.save(model_export_path, include_optimizer=False, save_format='tf') | |