001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.server.namenode;
019
020import org.apache.hadoop.hdfs.util.EnumCounters;
021
022/** Quota types. */
023public enum Quota {
024  /** The namespace usage, i.e. the number of name objects. */
025  NAMESPACE,
026  /** The storage space usage in bytes including replication. */
027  STORAGESPACE;
028
029  /** Counters for quota counts. */
030  public static class Counts extends EnumCounters<Quota> {
031    /** @return a new counter with the given namespace and storagespace usages. */
032    public static Counts newInstance(long namespace, long storagespace) {
033      final Counts c = new Counts();
034      c.set(NAMESPACE, namespace);
035      c.set(STORAGESPACE, storagespace);
036      return c;
037    }
038
039    public static Counts newInstance() {
040      return newInstance(0, 0);
041    }
042
043    Counts() {
044      super(Quota.class);
045    }
046  }
047
048  /**
049   * Is quota violated?
050   * The quota is violated if quota is set and usage > quota. 
051   */
052  static boolean isViolated(final long quota, final long usage) {
053    return quota >= 0 && usage > quota;
054  }
055
056  /**
057   * Is quota violated?
058   * The quota is violated if quota is set, delta > 0 and usage + delta > quota.
059   */
060  static boolean isViolated(final long quota, final long usage,
061      final long delta) {
062    return quota >= 0 && delta > 0 && usage > quota - delta;
063  }
064}