/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.lang.management.ManagementFactory;

import java.lang.management.MemoryPoolMXBean;

import java.lang.management.MemoryUsage;

/**

 * Utility class used by tests to get heap region usage.

 */

public final class HeapRegionUsageTool {

    /**

     * Get MemoryUsage from MemoryPoolMXBean which name matches passed string.

     *

     * @param name

     * @return MemoryUsage

     */

    private static MemoryUsage getUsage(String name){

        for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {

            if (pool.getName().matches(name)) {

                return pool.getUsage();

            }

        }

        return null;

    }

    /**

     * Get MemoryUsage of Eden space.

     *

     * @return MemoryUsage

     */

    public static MemoryUsage getEdenUsage() {

        return getUsage(".*Eden.*");

    }

    /**

     * Get MemoryUsage of Survivor space.

     *

     * @return MemoryUsage

     */

    public static MemoryUsage getSurvivorUsage() {

        return getUsage(".*Survivor.*");

    }

    /**

     * Get memory usage of Tenured space

     *

     * @return MemoryUsage

     */

    public static MemoryUsage getOldUsage() {

        return getUsage(".*(Old|Tenured).*");

    }

    /**

     * Get heap usage.

     *

     * @return MemoryUsage

     */

    public static MemoryUsage getHeapUsage() {

        return ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();

    }

    /**

     * Helper function to align up.

     *

     * @param value

     * @param alignment

     * @return aligned value

     */

    public static long alignUp(long value, long alignment) {

        return (value + alignment - 1) & ~(alignment - 1);

    }

    /**

     * Helper function to align down.

     *

     * @param value

     * @param alignment

     * @return aligned value

     */

    public static long alignDown(long value, long alignment) {

        return value & ~(alignment - 1);

    }

}