/*
 * The JTS Topology Suite is a collection of Java classes that
 * implement the fundamental operations required to validate a given
 * geo-spatial data set to a known topological specification.
 *
 * Copyright (C) 2001 Vivid Solutions
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * For more information, contact:
 *
 *     Vivid Solutions
 *     Suite #1A
 *     2328 Government Street
 *     Victoria BC  V8T 5G5
 *     Canada
 *
 *     (250)385-6040
 *     www.vividsolutions.com
 */
package com.revolsys.geometry.util;

/**
 * Utility functions to report JVM memory usage.
 *
 * @author mbdavis
 *
 */
public class Memory {
  public static final double GB = 1073741824;

  public static final double KB = 1024;

  public static final double MB = 1048576;

  public static String allString() {
    return "Used: " + usedString() + "   Free: " + freeString() + "   Total: " + totalString();
  }

  public static String format(final long mem) {
    if (mem < 2 * KB) {
      return mem + " bytes";
    }
    if (mem < 2 * MB) {
      return round(mem / KB) + " KB";
    }
    if (mem < 2 * GB) {
      return round(mem / MB) + " MB";
    }
    return round(mem / GB) + " GB";
  }

  public static long free() {
    final Runtime runtime = Runtime.getRuntime();
    return runtime.freeMemory();
  }

  public static String freeString() {
    return format(free());
  }

  public static double round(final double d) {
    return Math.ceil(d * 100) / 100;
  }

  public static long total() {
    final Runtime runtime = Runtime.getRuntime();
    return runtime.totalMemory();
  }

  public static String totalString() {
    return format(total());
  }

  public static long used() {
    final Runtime runtime = Runtime.getRuntime();
    return runtime.totalMemory() - runtime.freeMemory();
  }

  public static String usedString() {
    return format(used());
  }

  public static String usedTotalString() {
    return "Used: " + usedString() + "   Total: " + totalString();
  }
}