/**
* 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 com.aliyun.odps.io;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
/**
* IntWritable 提供了 int 的 {@link Writable} 和 {@link WritableComparable} 的实现
*/
@SuppressWarnings("rawtypes")
public class IntWritable implements WritableComparable {
private int value;
/**
* 默认构造int 值为0的 IntWritable.
*/
public IntWritable() {
}
/**
* 构造int 值为给定 value 的 IntWritable.
*
* @param value
*/
public IntWritable(int value) {
set(value);
}
/**
* 设置 IntWritable 的值
*
* @param value
*/
public void set(int value) {
this.value = value;
}
/**
* 返回此 IntWritable 的值
*
* @return
*/
public int get() {
return value;
}
@Override
public void readFields(DataInput in) throws IOException {
value = in.readInt();
}
@Override
public void write(DataOutput out) throws IOException {
out.writeInt(value);
}
/**
* 判断两个 IntWritable 是否相等.
*
* <p>
* 如果两个都是 IntWritable 且值相等,返回true,否则返回false
*
* @param o
* @return
*/
@Override
public boolean equals(Object o) {
if (!(o instanceof IntWritable)) {
return false;
}
IntWritable other = (IntWritable) o;
return this.value == other.value;
}
/**
* 计算哈希值,直接返回此 IntWritable 的值.
*/
@Override
public int hashCode() {
return value;
}
/**
* 比较两个 IntWritable 的值.
*
* @param o
* 比较对象
* @return (this < o ? -1 : (this == o) ? 0 :1))
*/
@Override
public int compareTo(Object o) {
int thisValue = this.value;
int thatValue = ((IntWritable) o).value;
return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
}
@Override
public String toString() {
return Integer.toString(value);
}
/**
* IntWritable 对象的 {@link WritableComparator} 自然顺序实现(升序).
*/
public static class Comparator extends WritableComparator {
public Comparator() {
super(IntWritable.class);
}
/**
* 基于二进制内容的 IntWritable 对象比较函数.
*/
@Override
public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
int thisValue = readInt(b1, s1);
int thatValue = readInt(b2, s2);
return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
}
}
static { // register this comparator
WritableComparator.define(IntWritable.class, new Comparator());
}
}