Memory.java

package ij.plugin;
import ij.*;
//import ij.process.*;
import ij.gui.*;
//import java.awt.*;
import java.io.*;
import ij.util.Tools;
import java.lang.reflect.*;


public class Memory implements PlugIn {
    String s;
    int index1, index2;
    File f;

    public void run(String arg) {
        changeMemoryAllocation();
        //IJ.log("setting="+getMemorySetting()/(1024*1024)+"MB");
        //IJ.log("maxMemory="+maxMemory()/(1024*1024)+"MB");
    }

    void changeMemoryAllocation() {
        IJ.maxMemory(); // forces IJ to cache old limit
        int max = (int)(getMemorySetting()/1048576L);
        if (max==0)
            {showError(); return;}
        GenericDialog gd = new GenericDialog("Memory");
        gd.addNumericField("Maximum Memory: ", max, 0, 4, "MB");
        gd.showDialog();
        if (gd.wasCanceled()) return;
        int max2 = (int)gd.getNextNumber();
        if (gd.invalidNumber()) {
            IJ.showMessage("Memory", "The number entered was invalid.");
            return;
        }
        if (max2<32 && IJ.isMacOSX()) max2 = 32;
        if (max2<8 && IJ.isWindows()) max2 = 8;
        if (max2==max) return;
        if (max2>=1700) {
            if (!IJ.showMessageWithCancel("Memory", 
            "Note: setting the memory limit to a value greater\n"
            +"than 1700MB may cause ImageJ to fail to start."))
                return;
        }
        try {
            String s2 = s.substring(0, index1) + max2 + s.substring(index2);
            FileOutputStream fos = new FileOutputStream(f);
            PrintWriter pw = new PrintWriter(fos);
            pw.print(s2);
            pw.close();
        } catch (IOException e) {
            String error = e.getMessage();
            if (error==null || error.equals("")) error = ""+e;
            String name = IJ.isMacOSX()?"Info.plist":"ImageJ.cfg";
            String msg = 
                   "Unable to update the file \"" + name + "\".\n"
                + " \n"
                + "\"" + error + "\"\n";
            IJ.showMessage("Memory", msg);
            return;
        }
        IJ.showMessage("Memory", "The new " + max2 +"MB limit will take effect after ImageJ is restarted.");        
    }

    public long getMemorySetting() {
        long max = 0L;
        if (IJ.isMacOSX()) {
            max = getMemorySetting("ImageJ.app/Contents/Info.plist");
        } else
            max = getMemorySetting("ImageJ.cfg");       
        return max;
    }

    void showError() {
        int max = (int)(maxMemory()/1048576L);
        String msg =
               "ImageJ is unable to change the memory limit. For\n"
            + "more information, refer to the installation notes.\n"
            + " \n";
        if (max>0)
            msg += "Current limit: " + max + "MB";
        IJ.showMessage("Memory", msg);
    }

    long getMemorySetting(String file) {
        String path = System.getProperty("user.dir")+File.separator+file;
        f = new File(path);
        if (!f.exists()) return 0L;
        long max = 0L;
        try {
            int size = (int)f.length();
            byte[] buffer = new byte[size];
            FileInputStream in = new FileInputStream(f);
            in.read(buffer, 0, size);
            s = new String(buffer, 0, size, "ISO8859_1");
            in.close();
            index1 = s.indexOf("-mx");
            if (index1==-1) index1 = s.indexOf("-Xmx");
            if (index1==-1) return 0L;
            if (s.charAt(index1+1)=='X') index1+=4; else index1+=3;
            index2 = index1;
            while (index2<s.length()-1 && Character.isDigit(s.charAt(++index2))) {}
            String s2 = s.substring(index1, index2);
            max = (long)Tools.parseDouble(s2, 0.0)*1024*1024;
        }
        catch (Exception e) {
            IJ.log(""+e);
            return 0L;
        }
        return max;
    }

    public long maxMemory() {
        // Call maxMemory using reflection so this class can be compiled with Java 1.3
        long max = 0L;
        try {
            Runtime rt = Runtime.getRuntime();
            Class c = rt.getClass();
            Method maxMemory = c.getDeclaredMethod("maxMemory", new Class[0]);
            Long l = (Long)maxMemory.invoke(rt, new Object[] {});
            max = l.longValue();
        } catch (Exception e) {}
        return max;
    }
    
}