DenseLongMapTest.java

package btools.util;

import java.util.Random;
import java.util.HashMap;
import java.util.HashSet;

import org.junit.Assert;
import org.junit.Test;

public class DenseLongMapTest
{
  @Test
  public void hashMapComparisonTest()
  {
    hashMapComparison( 100000, 100000, 100000 );
    hashMapComparison( 100000, 100000, 13000000 );
  }

  private void hashMapComparison( int mapsize, int trycount, long keyrange )
  {
    Random rand = new Random( 12345 );
    HashMap<Long,Integer> hmap = new HashMap<Long,Integer>();
    DenseLongMap dmap = new DenseLongMap( 512 );

    for( int i=0; i<mapsize; i++ )
    {
      int value = i%255;
      long k = (long)(rand.nextDouble()*keyrange);
      Long KK = new Long( k );

      hmap.put( KK, new Integer ( value ) );
      dmap.put( k, value ); // duplicate puts allowed!
    }

    for( int i=0; i<trycount; i++ )
    {
      long k = (long)(rand.nextDouble()*keyrange);
      Long KK = new Long( k );
      Integer VV = hmap.get( KK );
      int hvalue = VV == null ? -1 : VV.intValue();
      int dvalue = dmap.getInt( k );

      if ( hvalue != dvalue )
      {
        Assert.fail( "value missmatch for key " + k + " hashmap=" + hvalue + " densemap=" + dvalue );
      }
    }
  }

  @Test
  public void oneBitTest()
  {
    int keyrange = 300000;
    int mapputs = 100000;
    int trycount = 100000;

    Random rand = new Random( 12345 );
    HashSet<Long> hset = new HashSet<Long>();

    DenseLongMap dmap = new DenseLongMap( 512 );
    for( int i=0; i<mapputs; i++ )
    {
      long k = (long)(rand.nextDouble()*keyrange);
      hset.add( new Long( k ) );
      dmap.put( k, 0 );
    }
    for( int i=0; i<trycount; i++ )
    {
      long k = (long)(rand.nextDouble()*keyrange);
      boolean hcontains = hset.contains( new Long( k ) );
      boolean dcontains = dmap.getInt( k ) == 0;

      if ( hcontains != dcontains )
      {
        Assert.fail( "value missmatch for key " + k + " hashset=" + hcontains + " densemap=" + dcontains );
      }
    }
  }

  // @Test - memory test disabled for load reasons
  public void memoryUsageTest()
  {
    int keyrange = 32000000;
    int mapputs = keyrange * 2;

    Random rand = new Random( 12345 );
    DenseLongMap dmap = new DenseLongMap( 6 );

    System.gc();
    long mem1 = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();

    for( int i=0; i<mapputs; i++ )
    {
      int value = i%63;
      long k = (long)(rand.nextDouble()*keyrange);
      dmap.put( k, value );
    }

    System.gc();
    long mem2 = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();

    long memusage = mem2-mem1;

    if ( memusage > (keyrange/8)*7 )
    {
      Assert.fail( "memory usage too high: " + memusage + " for keyrange " + keyrange );
    }

    // need to use the map again for valid memory measure
    Assert.assertTrue( "out of range test", dmap.getInt(-1) == -1 );
  }

}