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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html#License
      3 /*
      4  ****************************************************************************
      5  * Copyright (C) 2004-2010, International Business Machines Corporation and *
      6  * others. All Rights Reserved.                                             *
      7  ****************************************************************************
      8  *
      9  */
     10 
     11 package com.ibm.icu.dev.test.timescale;
     12 
     13 import java.util.Random;
     14 
     15 import org.junit.Test;
     16 
     17 import com.ibm.icu.dev.test.TestFmwk;
     18 import com.ibm.icu.math.BigDecimal;
     19 import com.ibm.icu.util.UniversalTimeScale;
     20 
     21 /**
     22  * This class tests the UniversalTimeScale class by
     23  * generating ramdon values in range and making sure
     24  * that they round-trip correctly.
     25  */
     26 public class TimeScaleMonkeyTest extends TestFmwk
     27 {
     28 
     29     /**
     30      * The default constructor.
     31      */
     32     public TimeScaleMonkeyTest()
     33     {
     34     }
     35 
     36     private static final int LOOP_COUNT = 1000;
     37     private static final BigDecimal longMax = new BigDecimal(Long.MAX_VALUE);
     38 
     39     private Random ran = null;
     40 
     41     private long ranInt;
     42     private long ranMin;
     43     private long ranMax;
     44 
     45     private void initRandom(long min, long max)
     46     {
     47         BigDecimal interval = new BigDecimal(max).subtract(new BigDecimal(min));
     48 
     49         ranMin = min;
     50         ranMax = max;
     51         ranInt = 0;
     52 
     53         if (ran == null) {
     54             ran = createRandom();
     55         }
     56 
     57         if (interval.compareTo(longMax) < 0) {
     58             ranInt = interval.longValue();
     59         }
     60     }
     61 
     62     private final long randomInRange()
     63     {
     64         long value;
     65 
     66         if (ranInt != 0) {
     67             value = ran.nextLong() % ranInt;
     68 
     69             if (value < 0) {
     70                 value = -value;
     71             }
     72 
     73             value += ranMin;
     74         } else {
     75             do {
     76                 value = ran.nextLong();
     77             } while (value < ranMin || value > ranMax);
     78         }
     79 
     80         return value;
     81     }
     82 
     83     @Test
     84     public void TestRoundTrip()
     85     {
     86         for (int scale = 0; scale < UniversalTimeScale.MAX_SCALE; scale += 1) {
     87             long fromMin = UniversalTimeScale.getTimeScaleValue(scale, UniversalTimeScale.FROM_MIN_VALUE);
     88             long fromMax = UniversalTimeScale.getTimeScaleValue(scale, UniversalTimeScale.FROM_MAX_VALUE);
     89             int i = 0;
     90 
     91             initRandom(fromMin, fromMax);
     92 
     93             while (i < LOOP_COUNT) {
     94                 long value = randomInRange();
     95 
     96                 long rt = UniversalTimeScale.toLong(UniversalTimeScale.from(value, scale), scale);
     97 
     98                 if (rt != value) {
     99                     errln("Round-trip error: time scale = " + scale + ", value = " + value + ", round-trip = " + rt);
    100                 }
    101 
    102                 i += 1;
    103             }
    104         }
    105     }
    106 }
    107