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 */
018package org.apache.hadoop.hbase;
019
020import java.math.BigDecimal;
021import java.util.Objects;
022import org.apache.yetus.audience.InterfaceAudience;
023
024import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
025
026/**
027 * It is used to represent the size with different units. This class doesn't serve for the precise
028 * computation.
029 */
030@InterfaceAudience.Public
031public final class Size implements Comparable<Size> {
032  public static final Size ZERO = new Size(0, Unit.KILOBYTE);
033  private static final BigDecimal SCALE_BASE = BigDecimal.valueOf(1024D);
034
035  public enum Unit {
036    // keep the room to add more units for HBase 10.x
037    PETABYTE(100, "PB"),
038    TERABYTE(99, "TB"),
039    GIGABYTE(98, "GB"),
040    MEGABYTE(97, "MB"),
041    KILOBYTE(96, "KB"),
042    BYTE(95, "B");
043
044    private final int orderOfSize;
045    private final String simpleName;
046
047    Unit(int orderOfSize, String simpleName) {
048      this.orderOfSize = orderOfSize;
049      this.simpleName = simpleName;
050    }
051
052    public int getOrderOfSize() {
053      return orderOfSize;
054    }
055
056    public String getSimpleName() {
057      return simpleName;
058    }
059  }
060
061  private final double value;
062  private final Unit unit;
063
064  public Size(double value, Unit unit) {
065    if (value < 0) {
066      throw new IllegalArgumentException("The value:" + value + " can't be negative");
067    }
068    this.value = value;
069    this.unit = Preconditions.checkNotNull(unit);
070  }
071
072  /** Returns size unit */
073  public Unit getUnit() {
074    return unit;
075  }
076
077  /**
078   * get the value
079   */
080  public long getLongValue() {
081    return (long) value;
082  }
083
084  /**
085   * get the value
086   */
087  public double get() {
088    return value;
089  }
090
091  /**
092   * get the value which is converted to specified unit.
093   * @param unit size unit
094   * @return the converted value
095   */
096  public double get(Unit unit) {
097    if (value == 0) {
098      return value;
099    }
100    int diff = this.unit.getOrderOfSize() - unit.getOrderOfSize();
101    if (diff == 0) {
102      return value;
103    }
104
105    BigDecimal rval = BigDecimal.valueOf(value);
106    for (int i = 0; i != Math.abs(diff); ++i) {
107      rval = diff > 0 ? rval.multiply(SCALE_BASE) : rval.divide(SCALE_BASE);
108    }
109    return rval.doubleValue();
110  }
111
112  @Override
113  public int compareTo(Size other) {
114    int diff = unit.getOrderOfSize() - other.unit.getOrderOfSize();
115    if (diff == 0) {
116      return Double.compare(value, other.value);
117    }
118
119    BigDecimal thisValue = BigDecimal.valueOf(value);
120    BigDecimal otherValue = BigDecimal.valueOf(other.value);
121    if (diff > 0) {
122      for (int i = 0; i != Math.abs(diff); ++i) {
123        thisValue = thisValue.multiply(SCALE_BASE);
124      }
125    } else {
126      for (int i = 0; i != Math.abs(diff); ++i) {
127        otherValue = otherValue.multiply(SCALE_BASE);
128      }
129    }
130    return thisValue.compareTo(otherValue);
131  }
132
133  @Override
134  public String toString() {
135    return value + unit.getSimpleName();
136  }
137
138  @Override
139  public boolean equals(Object obj) {
140    if (obj == null) {
141      return false;
142    }
143    if (obj == this) {
144      return true;
145    }
146    if (obj instanceof Size) {
147      return compareTo((Size) obj) == 0;
148    }
149    return false;
150  }
151
152  @Override
153  public int hashCode() {
154    return Objects.hash(value, unit);
155  }
156}