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    
019    package org.apache.hadoop.io;
020    
021    import java.io.*;
022    
023    import org.apache.hadoop.classification.InterfaceAudience;
024    import org.apache.hadoop.classification.InterfaceStability;
025    
026    /** A WritableComparable for integer values stored in variable-length format.
027     * Such values take between one and five bytes.  Smaller values take fewer bytes.
028     * 
029     * @see org.apache.hadoop.io.WritableUtils#readVInt(DataInput)
030     */
031    @InterfaceAudience.Public
032    @InterfaceStability.Stable
033    public class VIntWritable implements WritableComparable<VIntWritable> {
034      private int value;
035    
036      public VIntWritable() {}
037    
038      public VIntWritable(int value) { set(value); }
039    
040      /** Set the value of this VIntWritable. */
041      public void set(int value) { this.value = value; }
042    
043      /** Return the value of this VIntWritable. */
044      public int get() { return value; }
045    
046      @Override
047      public void readFields(DataInput in) throws IOException {
048        value = WritableUtils.readVInt(in);
049      }
050    
051      @Override
052      public void write(DataOutput out) throws IOException {
053        WritableUtils.writeVInt(out, value);
054      }
055    
056      /** Returns true iff <code>o</code> is a VIntWritable with the same value. */
057      @Override
058      public boolean equals(Object o) {
059        if (!(o instanceof VIntWritable))
060          return false;
061        VIntWritable other = (VIntWritable)o;
062        return this.value == other.value;
063      }
064    
065      @Override
066      public int hashCode() {
067        return value;
068      }
069    
070      /** Compares two VIntWritables. */
071      @Override
072      public int compareTo(VIntWritable o) {
073        int thisValue = this.value;
074        int thatValue = o.value;
075        return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
076      }
077      
078      @Override
079      public String toString() {
080        return Integer.toString(value);
081      }
082    
083    }
084