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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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;
  
  /**
   * FloatWritable 提供了 float 的 {@link Writable} 和 {@link WritableComparable} 的实现
   */
  public class FloatWritable implements WritableComparable<FloatWritable> {
  
    private float value = 0.0f;
  
    /**
     * 默认构造 float 值为0.0的 FloatWritable.
     */
    public FloatWritable() {
  
    }
  
    /**
     * 构造 float 值为给定 value 的 FloatWritable.
     *
     * @param value
     */
    public FloatWritable(float value) {
      set(value);
    }
  
    @Override
    public void readFields(DataInput in) throws IOException {
      value = in.readFloat();
    }
  
    @Override
    public void write(DataOutput out) throws IOException {
      out.writeFloat(value);
    }
  
    /**
     * 设置 FloatWritable 的值
     *
     * @param value
     */
    public void set(float value) {
      this.value = value;
    }
  
    /**
     * 返回此 FloatWritable 的值
     *
     * @return
     */
    public float get() {
      return value;
    }
  
    /**
     * 判断两个 FloatWritable 是否相等.
     *
     * <p>
     * 如果两个都是 FloatWritable 且值相等，返回true，否则返回false
     *
     * @param o
     * @return
     */
    @Override
    public boolean equals(Object o) {
      if (o.getClass() != getClass()) {
        return false;
      }
  
      return this.value == ((FloatWritable) o).value;
    }
  
    /**
     * 计算哈希值，直接返回(int) Float.floatToIntBits
     */
    @Override
    public int hashCode() {
      return (int) Float.floatToIntBits(this.value);
    }
  
    /**
     * 比较两个 FloatWritable 的值.
     *
     * @param o
     *     比较对象
     * @return (this < o ? -1 : (this == o) ? 0 ：1))
     */
    @Override
    public int compareTo(FloatWritable o) {
      return (value < o.value ? -1 : (value == o.value ? 0 : 1));
    }
  
    @Override
    public String toString() {
      return Float.toString(value);
    }
  
    /**
     * FloatWritable 对象的 {@link WritableComparator} 自然顺序实现（升序）.
     */
    public static class Comparator extends WritableComparator {
  
      public Comparator() {
        super(FloatWritable.class);
      }
  
      /**
       * 基于二进制内容的 FloatWritable 对象比较函数.
       */
      @Override
      public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
        float thisValue = readFloat(b1, s1);
        float thatValue = readFloat(b2, s2);
        return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
      }
    }
  
    static { // register this comparator
      WritableComparator.define(FloatWritable.class, new Comparator());
    }
  }
  