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