#! /usr/bin/python
# -*- coding: utf-8 -*-

# Copyright (c) 2018, NVIDIA CORPORATION. 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.

import time

import numpy as np
import tensorflow as tf

__all__ = ['PrefillStagingAreasHook']


class PrefillStagingAreasHook(tf.train.SessionRunHook):

    def after_create_session(self, session, coord):
        # TODO: This assumes TF collections are ordered; is this safe?
        enqueue_ops = tf.get_collection('STAGING_AREA_PUTS')
        for i in range(len(enqueue_ops)):
            session.run(enqueue_ops[:i + 1])
