package org.simantics.db.impl;

import java.lang.ref.WeakReference;

public class MemWatch {
    public static boolean isLowOnMemory() {
        return isLowOnMemory;
    }
    private static boolean DBBUG = false;
    private static boolean isLowOnMemory = false;
    @SuppressWarnings("unused")
    private static MemWatch memWatch = new MemWatch();
    private Runtime runtime = Runtime.getRuntime();
    @SuppressWarnings("unused")
    private WeakReference<Watch> ref = new WeakReference<Watch>(new Watch());
    class Watch {
        @Override
        protected void finalize() throws Throwable {
            long fre = runtime.freeMemory();
            long tot = runtime.totalMemory();
            long max = runtime.maxMemory();
            if (tot < max || fre > max / 20) 
                isLowOnMemory = false;
            else
                isLowOnMemory = true;
            if (DBBUG)
              System.err.println("Garbage was collected using " + Thread.currentThread().getName()
              + " fre=" + fre + " tot=" + tot + " max=" + max
              + " low=" + isLowOnMemory);
            ref = new WeakReference<Watch>(new Watch());
            super.finalize();
        }
    }
}