common/org.eclipse.tracecompass.common.core/src/org/eclipse/tracecompass/common/core/format/DecimalUnitFormat.java

   1 /*******************************************************************************
   2  * Copyright (c) 2016 EfficiOS Inc., Michael Jeanson and others
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *******************************************************************************/
   9
  10 package org.eclipse.tracecompass.common.core.format;
  11
  12 import java.math.BigDecimal;
  13 import java.text.DecimalFormat;
  14 import java.text.FieldPosition;
  15 import java.text.Format;
  16 import java.text.NumberFormat;
  17 import java.text.ParsePosition;
  18 import java.util.Map;
  19
  20 import com.google.common.collect.ImmutableMap;
  21
  22 /**
  23  * Provides a formatter for decimal numbers with International System of Units
  24  * prefixes up to peta (quadrillion). It receives a number and formats it in the
  25  * closest thousand's unit, with at most 1 decimal.
  26  *
  27  * @author Michael Jeanson
  28  * @since 2.0
  29  */
  30 public class DecimalUnitFormat extends Format {
  31
  32     private static final long serialVersionUID = 3650332020346870384L;
  33
  34     /* International System of Units prefixes */
  35     private static final String KILO_PREFIX = "k"; //$NON-NLS-1$
  36     private static final String MEGA_PREFIX = "M"; //$NON-NLS-1$
  37     private static final String GIGA_PREFIX = "G"; //$NON-NLS-1$
  38     private static final String TERA_PREFIX = "T"; //$NON-NLS-1$
  39     private static final String PETA_PREFIX = "P"; //$NON-NLS-1$
  40
  41     private static final String MILLI_PREFIX = "m"; //$NON-NLS-1$
  42     private static final String MICRO_PREFIX = "µ"; //$NON-NLS-1$
  43     private static final String NANO_PREFIX = "n"; //$NON-NLS-1$
  44     private static final String PICO_PREFIX = "p"; //$NON-NLS-1$
  45
  46     private static final long KILO = 1000L;
  47     private static final long MEGA = 1000000L;
  48     private static final long GIGA = 1000000000L;
  49     private static final long TERA = 1000000000000L;
  50     private static final long PETA = 1000000000000000L;
  51
  52     private static final double MILLI = 0.001;
  53     private static final double MICRO = 0.000001;
  54     private static final double NANO  = 0.000000001;
  55     private static final double PICO  = 0.000000000001;
  56
  57     /* Map of prefix to exponent */
  58     private static final Map<String, Integer> PREFIX_MAP = ImmutableMap.<String, Integer>builder()
  59             .put(KILO_PREFIX, +3)
  60             .put(MEGA_PREFIX, +6)
  61             .put(GIGA_PREFIX, +9)
  62             .put(TERA_PREFIX, +12)
  63             .put(PETA_PREFIX, +15)
  64             .put(MILLI_PREFIX, -3)
  65             .put(MICRO_PREFIX, -6)
  66             .put(NANO_PREFIX, -9)
  67             .put(PICO_PREFIX, -12)
  68             .build();
  69     private static final Format FORMAT = new DecimalFormat("#.#"); //$NON-NLS-1$
  70     private final double fFactor;
  71
  72
  73     /**
  74      * Default constructor.
  75      */
  76     public DecimalUnitFormat() {
  77         super();
  78         fFactor = 1.0;
  79     }
  80
  81     /**
  82      * Constructor with multiplication factor.
  83      *
  84      * @param factor Multiplication factor to apply to the value
  85      */
  86     public DecimalUnitFormat(double factor) {
  87         super();
  88         fFactor = factor;
  89     }
  90
  91     @Override
  92     public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) {
  93         if (obj instanceof Number) {
  94             Number num = (Number) obj;
  95
  96             /* Apply the multiplication factor before formatting */
  97             double value = num.doubleValue() * fFactor;
  98
  99             double abs = Math.abs(value);
 100
 101             if (Double.isInfinite(value) || Double.isNaN(value) || abs < PICO) {
 102                 return toAppendTo.append(FORMAT.format(value));
 103             }
 104
 105             if (abs >= 1) {
 106                 if (abs > Long.MAX_VALUE) {
 107                     return toAppendTo.append(num);
 108                 }
 109                 if (abs >= PETA) {
 110                     return toAppendTo.append(FORMAT.format(value / PETA)).append(' ').append(PETA_PREFIX);
 111                 }
 112                 if (abs >= TERA) {
 113                     return toAppendTo.append(FORMAT.format(value / TERA)).append(' ').append(TERA_PREFIX);
 114                 }
 115                 if (abs >= GIGA) {
 116                     return toAppendTo.append(FORMAT.format(value / GIGA)).append(' ').append(GIGA_PREFIX);
 117                 }
 118                 if (abs >= MEGA) {
 119                     return toAppendTo.append(FORMAT.format(value / MEGA)).append(' ').append(MEGA_PREFIX);
 120                 }
 121                 if (abs >= KILO) {
 122                     return toAppendTo.append(FORMAT.format(value / KILO)).append(' ').append(KILO_PREFIX);
 123                 }
 124
 125                 return toAppendTo.append(FORMAT.format(value));
 126             }
 127
 128             if (abs < NANO) {
 129                 return toAppendTo.append(FORMAT.format(value * TERA)).append(' ').append(PICO_PREFIX);
 130             }
 131             if (abs < MICRO) {
 132                 return toAppendTo.append(FORMAT.format(value * GIGA)).append(' ').append(NANO_PREFIX);
 133             }
 134             if (abs < MILLI) {
 135                 return toAppendTo.append(FORMAT.format(value * MEGA)).append(' ').append(MICRO_PREFIX);
 136             }
 137
 138             return toAppendTo.append(FORMAT.format(value * KILO)).append(' ').append(MILLI_PREFIX);
 139         }
 140
 141         throw new IllegalArgumentException("Cannot format given Object as a Number: " + obj); //$NON-NLS-1$
 142     }
 143
 144     /**
 145      * @since 2.1
 146      */
 147     @Override
 148     public Number parseObject(String source, ParsePosition pos) {
 149         Number number = NumberFormat.getInstance().parse(source, pos);
 150         if (number == null) {
 151             return null;
 152         }
 153         String unit = source.substring(pos.getIndex()).trim();
 154         Integer exponent = null;
 155         if (!unit.isEmpty()) {
 156             String prefix = unit.substring(0, 1);
 157             exponent = PREFIX_MAP.get(prefix);
 158         }
 159         if (exponent != null && Double.isFinite(number.doubleValue())) {
 160             BigDecimal bd = new BigDecimal(number.toString());
 161             bd = bd.movePointRight(exponent.intValue());
 162             if (bd.remainder(BigDecimal.ONE).equals(BigDecimal.ZERO) &&
 163                     bd.abs().compareTo(new BigDecimal(Long.MAX_VALUE)) < 0) {
 164                 return bd.longValue();
 165             }
 166             return bd.doubleValue();
 167         }
 168         return number;
 169     }
 170 }