heapmonitor.java

The WLAN Traffic Visualizer is a platform independent Java program providing accurate measurement of

package view;

//Copyright (C) 2008 Harald Unander
//
//    This file is part of WlanTV.
//
//    WlanTV 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.
//
//    WlanTV 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 WlanTV.  If not, see <http://www.gnu.org/licenses/>.

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Timer;
import java.util.TimerTask;

import javax.swing.JPanel;

import main.Main;

@SuppressWarnings("serial")
public class HeapMonitor extends JPanel {
	private final int HISTORY_COUNT = 120;
	private final int UNIT = 10;
	private final Runtime rt = Runtime.getRuntime();
	private final int maxMem = (int)rt.maxMemory()/1000000;
	private final BasicStroke STROKE = new BasicStroke(0);
	private Sample[] history = new Sample[HISTORY_COUNT];

	private int pos;
	private BufferedImage buffer;	
	private int allocatedMem;
	private int freeMem;
	private int usedMem;
	
	public HeapMonitor()
	{
		for (int i=0; i<HISTORY_COUNT; i++) {
			history[i] = new Sample();
		}
		setPreferredSize(new Dimension(HISTORY_COUNT,0));
		setMaximumSize(new Dimension(HISTORY_COUNT,30));
		Timer t = new Timer();
		t.scheduleAtFixedRate(new Refresh(),1000,1000);
	}

	@Override
	public void paint(Graphics g)
	{
		if (buffer != null)
			g.drawImage(buffer, 0, 0, this);
	}

	class Refresh extends TimerTask {
		@Override
		public void run() {
			allocatedMem = (int)rt.totalMemory()/1000000;
			usedMem = allocatedMem - (int)rt.freeMemory()/1000000;
			freeMem = maxMem - usedMem;
			buffer = (BufferedImage)createImage(getWidth(),getHeight());
			Graphics2D g2d = buffer.createGraphics();
			g2d.setFont(Main.SMALLFONT.deriveFont(9F));
			g2d.setPaint(Color.RED);
			g2d.drawString(Integer.toString(maxMem)+"MB",2,10);
			double w = ((double) getWidth()-1)/HISTORY_COUNT;
			double h = ((double) getHeight()-1)/maxMem*UNIT;
			g2d.translate(0, getHeight()-1);
			g2d.scale(w,-h);
			g2d.setStroke(STROKE);
			history[pos].used = usedMem;
			history[pos].allocated = allocatedMem;

//			System.out.print(pos+":");
			for (int i=0, x=HISTORY_COUNT-pos; i<HISTORY_COUNT; i++) {
				g2d.setPaint(Color.BLACK);
				g2d.drawRect((x+i)%HISTORY_COUNT, 0, 1, history[i].used/UNIT);
				g2d.fillRect((x+i)%HISTORY_COUNT, 0, 1, history[i].used/UNIT);
				g2d.setPaint(Color.GREEN);
				g2d.drawRect((x+i)%HISTORY_COUNT, history[i].allocated/UNIT, 1, 0);
//				System.out.print(history[i]+" ");
			}
			pos++;
			pos %= HISTORY_COUNT;

//			System.out.println();
			
			g2d.setPaint(Color.BLACK);
			g2d.drawRect(0, 0, HISTORY_COUNT, maxMem/UNIT);
			g2d.setPaint(Color.RED);
			g2d.drawLine(0, maxMem/UNIT, HISTORY_COUNT, maxMem/UNIT);

			setToolTipText(getMemReport());

			repaint();
		}
	}

	public boolean memOk(boolean print) {
//		count++;
//		if (count%100 == 0 || print) {
//			if (count%1000 == 0 || print) {
//				System.out.println(count+
//						" Used:" + usedMem +
//						" Max:" + maxMem);
//			}
//			return freeMem > 495; //test
			return freeMem > 25;
//		}
//		else {
//			return true;
//		}
	}

	public String getMemReport() {
		return 
		(
				"Heap used (black color)" + usedMem + "MB, max (red color) " + maxMem + "MB"
		);
	}
	
	class Sample {
		int allocated = 0;
		int used = 0;
	}
}