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
022 import java.io.DataInput;
023 import java.io.DataOutput;
024 import java.io.IOException;
025
026 import org.apache.hadoop.classification.InterfaceAudience;
027 import org.apache.hadoop.classification.InterfaceStability;
028
029 /** A WritableComparable for ints. */
030 @InterfaceAudience.Public
031 @InterfaceStability.Stable
032 public class IntWritable implements WritableComparable<IntWritable> {
033 private int value;
034
035 public IntWritable() {}
036
037 public IntWritable(int value) { set(value); }
038
039 /** Set the value of this IntWritable. */
040 public void set(int value) { this.value = value; }
041
042 /** Return the value of this IntWritable. */
043 public int get() { return value; }
044
045 public void readFields(DataInput in) throws IOException {
046 value = in.readInt();
047 }
048
049 public void write(DataOutput out) throws IOException {
050 out.writeInt(value);
051 }
052
053 /** Returns true iff <code>o</code> is a IntWritable with the same value. */
054 @Override
055 public boolean equals(Object o) {
056 if (!(o instanceof IntWritable))
057 return false;
058 IntWritable other = (IntWritable)o;
059 return this.value == other.value;
060 }
061
062 @Override
063 public int hashCode() {
064 return value;
065 }
066
067 /** Compares two IntWritables. */
068 @Override
069 public int compareTo(IntWritable o) {
070 int thisValue = this.value;
071 int thatValue = o.value;
072 return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1));
073 }
074
075 @Override
076 public String toString() {
077 return Integer.toString(value);
078 }
079
080 /** A Comparator optimized for IntWritable. */
081 public static class Comparator extends WritableComparator {
082 public Comparator() {
083 super(IntWritable.class);
084 }
085
086 @Override
087 public int compare(byte[] b1, int s1, int l1,
088 byte[] b2, int s2, int l2) {
089 int thisValue = readInt(b1, s1);
090 int thatValue = readInt(b2, s2);
091 return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1));
092 }
093 }
094
095 static { // register this comparator
096 WritableComparator.define(IntWritable.class, new Comparator());
097 }
098 }
099