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     */
018    package org.apache.hadoop.hdfs.server.namenode;
019    
020    import org.apache.hadoop.hdfs.util.EnumCounters;
021    
022    /** Quota types. */
023    public enum Quota {
024      /** The namespace usage, i.e. the number of name objects. */
025      NAMESPACE,
026      /** The diskspace usage in bytes including replication. */
027      DISKSPACE;
028    
029      /** Counters for quota counts. */
030      public static class Counts extends EnumCounters<Quota> {
031        /** @return a new counter with the given namespace and diskspace usages. */
032        public static Counts newInstance(long namespace, long diskspace) {
033          final Counts c = new Counts();
034          c.set(NAMESPACE, namespace);
035          c.set(DISKSPACE, diskspace);
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    }