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 com.aliyun.odps.data.IntervalYearMonth;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  
  /**
   * IntervalYearMonthWritable 提供了 interval_year_month 的 {@link Writable} 和 {@link WritableComparable}
   * 的实现
   */
  public class IntervalYearMonthWritable implements WritableComparable<IntervalYearMonthWritable> {
  
    private final static int MONTHS_PER_YEAR = 12;
    private int totalMonths;
  
    /**
     * 默认构造 interval 值为0的 IntervalYearMonthWritable.
     */
    public IntervalYearMonthWritable() {
    }
  
    /**
     * 根据给定的 IntervalYearMonth 对象构造 IntervalYearMonthWritable
     *
     * @param value
     */
    public IntervalYearMonthWritable(IntervalYearMonth value) {
      this(value.getTotalMonths());
    }
  
    /**
     * 构造总月数为totalMonths的interval writable
     *
     * @param totalMonths 该interval的总月数
     */
    public IntervalYearMonthWritable(int totalMonths) {
      set(totalMonths);
    }
  
    /**
     * 返回此 IntervalYearMonthWritable 的值
     *
     * @return 这个interval对应的IntervalYearMonth对象
     */
    public IntervalYearMonth get() {
      return new IntervalYearMonth(totalMonths);
    }
  
    /**
     * 设置该IntervalYearMonthWritable的值
     *
     * @param totalMonths 总月数
     */
    public void set(int totalMonths) {
      this.totalMonths = totalMonths;
    }
  
    /**
     * 返回此 IntervalYearMonthWritable 的总月数
     *
     * @return 这个interval对应的总月数
     */
    public int getTotalMonths() {
      return totalMonths;
    }
  
    /**
     * 使用IntervalYearMonth对象设置该writable的值
     */
    public void set(IntervalYearMonth interval) {
      set(interval.getTotalMonths());
    }
  
    @Override
    public void write(DataOutput out) throws IOException {
      out.write(totalMonths);
    }
  
    @Override
    public void readFields(DataInput in) throws IOException {
      totalMonths = in.readInt();
    }
  
    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;
  
      IntervalYearMonthWritable that = (IntervalYearMonthWritable) o;
  
      return totalMonths == that.totalMonths;
  
    }
  
    @Override
    public int hashCode() {
      return totalMonths;
    }
  
    @Override
    public int compareTo(IntervalYearMonthWritable o) {
      return totalMonths < o.totalMonths ? -2 : totalMonths == o.totalMonths ? 0 : 2;
    }
  
    /**
     * IntervalYearMonthWritable 对象的 {@link WritableComparator} 自然顺序实现（升序）.
     */
    public static class Comparator extends WritableComparator {
  
      public Comparator() {
        super(IntervalYearMonthWritable.class);
      }
  
      /**
       * 基于二进制内容的 IntervalYearMonthWritable 对象比较函数.
       */
      @Override
      public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
        long thisValue = readLong(b1, s1);
        long thatValue = readLong(b2, s2);
        return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
      }
    }
  
    /**
     * IntervalYearMonthWritable 对象的 {@link WritableComparator} 降序实现.
     */
    public static class DecreasingComparator extends Comparator {
  
      @Override
      public int compare(WritableComparable a, WritableComparable b) {
        return -super.compare(a, b);
      }
  
      @Override
      public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
        return -super.compare(b1, s1, l1, b2, s2, l2);
      }
    }
  
    static { // register default comparator
      WritableComparator.define(IntervalYearMonthWritable.class, new Comparator());
    }
  
  }
  