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

   1 /*******************************************************************************
   2  * Copyright (c) 2016 Ericsson
   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.text.DecimalFormat;
  13 import java.text.FieldPosition;
  14 import java.text.Format;
  15 import java.text.ParsePosition;
  16
  17 /**
  18  * Provides a formatter for data sizes along with the unit of size (KG, MB, GB
  19  * ou TB). It receives a size in bytes and it formats a number in the closest
  20  * thousand's unit, with at most 3 decimals.
  21  *
  22  * @author Matthew Khouzam
  23  * @since 2.0
  24  */
  25 public class DataSizeWithUnitFormat extends Format {
  26
  27     private static final long serialVersionUID = 3934127385682676804L;
  28     private static final String B = "B"; //$NON-NLS-1$
  29     private static final String KB = "KB"; //$NON-NLS-1$
  30     private static final String MB = "MB"; //$NON-NLS-1$
  31     private static final String GB = "GB"; //$NON-NLS-1$
  32     private static final String TB = "TB"; //$NON-NLS-1$
  33     private static final long KILO = 1024;
  34     private static final Format FORMAT = new DecimalFormat("#.###"); //$NON-NLS-1$
  35
  36     @Override
  37     public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) {
  38         if (obj instanceof Number) {
  39             Number num = (Number) obj;
  40             double value = num.doubleValue();
  41             double abs = Math.abs(value);
  42             if (value == 0) {
  43                 return toAppendTo.append("0"); //$NON-NLS-1$
  44             }
  45             if (abs > KILO * KILO * KILO * KILO) {
  46                 return toAppendTo.append(FORMAT.format(value / (KILO * KILO * KILO * KILO))).append(' ').append(TB);
  47             }
  48             if (abs > KILO * KILO * KILO) {
  49                 return toAppendTo.append(FORMAT.format(value / (KILO * KILO * KILO))).append(' ').append(GB);
  50             }
  51             if (abs > KILO * KILO) {
  52                 return toAppendTo.append(FORMAT.format(value / (KILO * KILO))).append(' ').append(MB);
  53             }
  54             if (abs > KILO) {
  55                 return toAppendTo.append(FORMAT.format(value / (KILO))).append(' ').append(KB);
  56             }
  57             return toAppendTo.append(FORMAT.format(value)).append(' ').append(B);
  58         }
  59         return toAppendTo;
  60     }
  61
  62     @Override
  63     public Object parseObject(String source, ParsePosition pos) {
  64         return source == null ? "" : source; //$NON-NLS-1$
  65     }
  66 }