MemoryMonitor.java

package ij.plugin;
import ij.*;
import ij.gui.*;
import ij.process.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;

public class MemoryMonitor implements PlugIn {
    int width = 200;
    int height = 75;
    long fps, startTime, elapsedTime;
    ImageProcessor ip;
    int frames;
    ImageCanvas ic;
    float[] mem;
    int index;
    long value;
    int max = 12*1204*1024; // 12MB
    long maxMemory = IJ.maxMemory();

    public void run(String arg) {
        if (IJ.altKeyDown()) {
            // simulate frame grabber
            width = 640;
            height = 480;
        }
        ip = new ByteProcessor(width, height, new byte[width*height], null);
        ip.setColor(Color.white);
        ip.fill();
        ip.setColor(Color.black);
        ip.setFont(new Font("SansSerif",Font.PLAIN,12));
        ip.setAntialiasedText(true);
        ip.snapshot();
        ImagePlus imp = new ImagePlus("Memory", ip);
        imp.show();
        imp.lock();
        ic = imp.getCanvas();
        mem = new float[width+1];
        Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
        startTime = System.currentTimeMillis();
        imp.unlock();
    }
    
    void showValue() {
        double value2 = (double)value/1048576L;
        String s = IJ.d2s(value2,value2>50?0:2)+"MB";
        if (maxMemory>0L) {
            double percent = value*100/maxMemory;
            s += " ("+(percent<1.0?"<1":IJ.d2s(percent,0)) + "%)";
        }
        if (width==640) {
            elapsedTime = System.currentTimeMillis()-startTime;
            if (elapsedTime>0) {
                double scale = ic.getMagnification();
                fps = (frames*10000)/elapsedTime;
                s += ", " + fps/10 + "." + fps%10 + " fps";
            }
        }
        ip.moveTo(2, 15);
        ip.drawString(s);
    }

    long memoryInUse() {
        long freeMem = Runtime.getRuntime().freeMemory();
        long totMem = Runtime.getRuntime().totalMemory();
        return  totMem-freeMem;
    }

    void updatePixels() {
        long used = memoryInUse();
        if (frames%10==0) value=used;
        if (used>0.9*max) max*=2;
        mem[index++] = (float)used;
        if (index==mem.length) index = 0;
        ip.reset();
        int index2 = index+1;
        if (index2==mem.length) index2 = 0;
        double scale = (double)height/max;
        ip.moveTo(0, height-(int)(mem[index2]*scale));
        for (int x=1; x<width; x++) {
            index2++;
            if (index2==mem.length) index2 = 0;
            ip.lineTo(x, height-(int)(mem[index2]*scale));
        }
    }

}