PerfByteArray.java

/*
 * Copyright 2009-2016 Tilmann Zaeschke. All rights reserved.
 * 
 * This file is part of ZooDB.
 * 
 * ZooDB is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * ZooDB is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with ZooDB.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * See the README and COPYING files for further information. 
 */
package org.zoodb.test.java;

import java.nio.ByteBuffer;

/**
 * Compare performance of direct buffer vs non-direct buffer.
 * 
 * Result direct buffers are 3-4 times faster for writing and 20 times faster for reading.
 * Creation may take 2 times longer for direct buffers.
 * 
 * @author Tilmann Zaeschke
 *
 */
public class PerfByteArray {
	
	private static final int MAX_J = 10000;
	
	public static void main(String[] args) {
		new PerfByteArray().run();
	}

	private void run() {
		createArrays();
		createArrays();
		createArrays();
		
		writeByte();
		writeByte();
		writeByte();

		writeLong();
		writeLong();
		writeLong();
		
		readByte();
		readByte();
		readByte();

		readLong();
		readLong();
		readLong();
	}
	
	private void createArrays() {
		start("create N");
		for (int i = 0; i < 10000; i++) {
			ByteBuffer.allocate(16000);
		}
		stop("create N");
		start("create D");
		for (int i = 0; i < 10000; i++) {
			ByteBuffer.allocateDirect(16000);
		}
		stop("create D");
	}
	
	private void writeByte() {
		ByteBuffer bbN = ByteBuffer.allocate(160000);
		ByteBuffer bbD = ByteBuffer.allocateDirect(160000);
		byte b = 10;
		start("write b N");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbN.put(b);
			}
			bbN.rewind();
		}
		stop("write b N");
		start("write b D");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbD.put(b);
			}
			bbD.rewind();
		}
		stop("write b D");
	}
	
	private void writeLong() {
		ByteBuffer bbN = ByteBuffer.allocate(160000);
		ByteBuffer bbD = ByteBuffer.allocateDirect(160000);
		start("write l N");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbN.putLong(10);
			}
			bbN.rewind();
		}
		stop("write l N");
		start("write l D");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbD.putLong(10);
			}
			bbD.rewind();
		}
		stop("write l D");
		
	}
	
	private void readByte() {
		ByteBuffer bbN = ByteBuffer.allocate(160000);
		ByteBuffer bbD = ByteBuffer.allocateDirect(160000);
		byte b = 10;
		start("read b N");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbN.get(b);
			}
			bbN.rewind();
		}
		stop("read b N");
		start("read b D");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbD.get();
			}
			bbD.rewind();
		}
		stop("read b D");
	}
	
	private void readLong() {
		ByteBuffer bbN = ByteBuffer.allocate(160000);
		ByteBuffer bbD = ByteBuffer.allocateDirect(160000);
		start("read l N");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbN.getLong();
			}
			bbN.rewind();
		}
		stop("read l N");
		start("read l D");
		for (int j = 0; j < MAX_J; j++) {
			for (int i = 0; i < 10000; i++) {
				bbD.getLong();
			}
			bbD.rewind();
		}
		stop("read l D");
		
	}
	
	private long time;
	private void start(String msg) {
		time = System.currentTimeMillis();
	}
	private void stop(String msg) {
		long t = System.currentTimeMillis() - time;
		double td = t/1000.0;
		System.out.println(msg + ": " + td);
	}
}