Android FloatBuffer benchmark

package droid.ryanm.buffertest;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.util.Random;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ScrollView;
import android.widget.TextView;

/**
 * @author ryanm
 */
public class BufferTest extends Activity
{
    private ScrollView sv;

    private TextView tv;

    private ByteBuffer bb;

    private FloatBuffer floats;

    private IntBuffer ints;

    private float[] data;

    private int[] intData;

    private Thread testThread = new Thread( "Buffer perf test" ) {
        @Override
        public void run()
        {
            int e = 10000;

            bb = ByteBuffer.allocateDirect( 4 * e ).order( ByteOrder.nativeOrder() );
            floats = bb.asFloatBuffer();
            ints = bb.asIntBuffer();

            data = data( e );
            intData = new int[ e ];

            e = 16;
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( e *= 2 );
            test( 10000 );
        };
    };

    private void test( int elements )
    {
        int time = 1000;
        log( elements + " elements" );
        singlePut( data, elements, floats, time );
        bulkPut( data, elements, floats, time );
        bulkIntPut( intData, elements, ints, time );
        bulkConvertPut( data, elements, ints, time );
    }

    private void singlePut( float[] data, int elements, FloatBuffer target, int testTime )
    {
        long start = System.currentTimeMillis();
        long elapsed = 0;
        int reps = 0;

        target.clear();

        do
        {
            for( int i = 0; i < elements; i++ )
            {
                target.put( i, data[ i ] );
            }
            reps++;
            elapsed = System.currentTimeMillis() - start;
        }
        while( elapsed < testTime );

        long bytes = ( long ) elements * ( long ) reps * 4;

        log( "Single\t\t" + bytes / elapsed + " kbps" );
    }

    private void bulkPut( float[] data, int elements, FloatBuffer target, int testTime )
    {
        long start = System.currentTimeMillis();
        long elapsed = 0;
        int reps = 0;

        target.clear();

        do
        {
            target.put( data, 0, elements );
            target.flip();

            reps++;
            elapsed = System.currentTimeMillis() - start;
        }
        while( elapsed < testTime );

        long bytes = ( long ) elements * ( long ) reps * 4;

        log( "Bulk\t\t" + bytes / elapsed + " kbps" );
    }

    private void bulkConvertPut( float[] data, int elements, IntBuffer target, int testTime )
    {
        long start = System.currentTimeMillis();
        long elapsed = 0;
        int reps = 0;

        target.clear();

        do
        {
            for( int i = 0; i < elements; i++ )
            {
                intData[ i ] = Float.floatToIntBits( data[ i ] );
            }

            target.put( intData, 0, elements );
            target.flip();

            reps++;
            elapsed = System.currentTimeMillis() - start;
        }
        while( elapsed < testTime );

        long bytes = ( long ) elements * ( long ) reps * 4;

        log( "convert\t" + bytes / elapsed + " kbps" );
    }

    private void bulkIntPut( int[] data, int elements, IntBuffer target, int testTime )
    {
        long start = System.currentTimeMillis();
        long elapsed = 0;
        int reps = 0;

        target.clear();

        do
        {
            target.put( intData, 0, elements );
            target.flip();

            reps++;
            elapsed = System.currentTimeMillis() - start;
        }
        while( elapsed < testTime );

        long bytes = ( long ) elements * ( long ) reps * 4;

        log( "int\t\t\t" + bytes / elapsed + " kbps" );
    }

    @Override
    public void onCreate( Bundle savedInstanceState )
    {
        super.onCreate( savedInstanceState );

        tv = new TextView( this );
        sv = new ScrollView( this );
        sv.addView( tv );
        setContentView( sv );

        testThread.start();
    }

    private void log( final String s )
    {
        Log.i( "BufferTest", s );

        tv.post( new Runnable() {

            @Override
            public void run()
            {
                StringBuilder buff = new StringBuilder( tv.getText() );
                buff.append( s ).append( "\n" );
                tv.setText( buff.toString() );
            }
        } );
    }

    private float[] data( int elements )
    {
        float[] data = new float[ elements ];
        Random rng = new Random();

        for( int i = 0; i < data.length; i++ )
        {
            data[ i ] = 100 * rng.nextFloat();
        }

        return data;
    }
}