save tensorflow model to .ckpt and .pb

save_tf_model.py

"""
load model
"""

def load_model(model_dir):
    start = time.time()
    model_exp = os.path.expanduser(model_dir)
    if (os.path.isfile(model_exp)):
        print('Model filename: %s' % model_exp)
        with gfile.FastGFile(model_exp, 'rb') as f:
            graph_def = tf.GraphDef()
            graph_def.ParseFromString(f.read())
            tf.import_graph_def(graph_def, name='')
    else:
        print('Model directory: %s' % model_exp)
        meta_file, ckpt_file = get_model_filenames(model_exp)

        print('Metagraph file: %s' % meta_file)
        print('Checkpoint file: %s' % ckpt_file)

        saver = tf.train.import_meta_graph(os.path.join(model_exp, meta_file))
        saver.restore(tf.get_default_session(), os.path.join(model_exp, ckpt_file))
    end = time.time()
    print("model loading time: ", end-start)


def get_model_filenames(model_dir):
    files = os.listdir(model_dir)
    meta_files = [s for s in files if s.endswith('.meta')]
    if len(meta_files) == 0:
        raise ValueError('No meta file found in the output directory (%s)' % model_dir)
    elif len(meta_files) > 1:
        raise ValueError('There should not be more than one meta file in the output directory (%s)' % model_dir)
    meta_file = meta_files[0]
    ckpt = tf.train.get_checkpoint_state(model_dir)
    if ckpt and ckpt.model_checkpoint_path:
        ckpt_file = os.path.basename(ckpt.model_checkpoint_path)
        return meta_file, ckpt_file

    meta_files = [s for s in files if '.ckpt' in s]
    max_step = -1
    for f in files:
        step_str = re.match(r'(^model-[\w\- ]+.ckpt-(\d+))', f)
        if step_str is not None and len(step_str.groups()) >= 2:
            step = int(step_str.groups()[1])
            if step > max_step:
                max_step = step
                ckpt_file = step_str.groups()[0]
    return meta_file, ckpt_file
  

 """
 save ckpt meta file 
 """
  
def save_variables_and_metagraph(sess, saver, summary_writer, model_dir, model_name, step):
    # Save the model checkpoint
    print('Saving variables')
    start_time = time.time()
    checkpoint_path = os.path.join(model_dir, 'model-%s.ckpt' % model_name)
    saver.save(sess, checkpoint_path, global_step=step, write_meta_graph=False)
    save_time_variables = time.time() - start_time
    print('Variables saved in %.2f seconds' % save_time_variables)
    metagraph_filename = os.path.join(model_dir, 'model-%s.meta' % model_name)
    save_time_metagraph = 0
    if not os.path.exists(metagraph_filename):
        print('Saving metagraph')
        start_time = time.time()
        saver.export_meta_graph(metagraph_filename)
        save_time_metagraph = time.time() - start_time
        print('Metagraph saved in %.2f seconds' % save_time_metagraph)
    summary = tf.Summary()
    # pylint: disable=maybe-no-member
    summary.value.add(tag='time/save_variables', simple_value=save_time_variables)
    summary.value.add(tag='time/save_metagraph', simple_value=save_time_metagraph)
    summary_writer.add_summary(summary, step)
  
  
  """
  save ckpt to pb file
  
  """
  def save_ckpt_to_pb(sess, model_dir):

    load_model(model_dir)
    # Retrieve the protobuf graph definition and fix the batch norm nodes
    input_graph_def = sess.graph.as_graph_def()
    # Freeze the graph def
    output_graph_def = freeze_graph_def(sess, input_graph_def, 'embeddings')
    output_graph = os.path.join(model_dir, "model.pb")
    with tf.gfile.GFile(output_graph, 'wb') as f:
        f.write(output_graph_def.SerializeToString())
    print("%d ops in the final graph: %s" % (len(output_graph_def.node), output_graph))



def freeze_graph_def(sess, input_graph_def, output_node_names):
    for node in input_graph_def.node:
        if node.op == 'RefSwitch':
            node.op = 'Switch'
            for index in xrange(len(node.input)):
                if 'moving_' in node.input[index]:
                    node.input[index] = node.input[index] + '/read'
        elif node.op == 'AssignSub':
            node.op = 'Sub'
            if 'use_locking' in node.attr: del node.attr['use_locking']
        elif node.op == 'AssignAdd':
            node.op = 'Add'
            if 'use_locking' in node.attr: del node.attr['use_locking']

    # Get the list of important nodes
    whitelist_names = []
    for node in input_graph_def.node:
        if (node.name.startswith('InceptionResnetV1') or node.name.startswith('embeddings') or
                node.name.startswith('phase_train') or node.name.startswith('Bottleneck') or node.name.startswith(
                    'Logits')):
            whitelist_names.append(node.name)

    # Replace all the variables in the graph with constants of the same values
    output_graph_def = tf.graph_util.convert_variables_to_constants(
        sess, input_graph_def, output_node_names.split(","),
        variable_names_whitelist=whitelist_names)
    return output_graph_def