/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */
package org.apache.hadoop.hdfs.server.namenode;

import java.io.IOException;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;

/**
 *
 * NameNodeResourceChecker provides a method -
 * <code>hasAvailableDiskSpace</code> - which will return true if and only if
 * the NameNode has disk space available on all required volumes, and any volume
 * which is configured to be redundant. Volumes containing file system edits dirs
 * are added by default, and arbitrary extra volumes may be configured as well.
 */
@InterfaceAudience.Private
public class NameNodeResourceChecker {
  /**
   * Create a NameNodeResourceChecker, which will check the edits dirs and any
   * additional dirs to check set in <code>conf</code>.
   */
  public NameNodeResourceChecker(Configuration conf) throws IOException {
  }


  /**
   * Return true if disk space is available on at least one of the configured
   * redundant volumes, and all of the configured required volumes.
   *
   * @return True if the configured amount of disk space is available on at
   *         least one redundant volume and all of the required volumes, false
   *         otherwise.
   */
  public boolean hasAvailableDiskSpace() {
    return true;
  }
}
