| // |
| // ======================================================================== |
| // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd. |
| // ------------------------------------------------------------------------ |
| // All rights reserved. This program and the accompanying materials |
| // are made available under the terms of the Eclipse Public License v1.0 |
| // and Apache License v2.0 which accompanies this distribution. |
| // |
| // The Eclipse Public License is available at |
| // http://www.eclipse.org/legal/epl-v10.html |
| // |
| // The Apache License v2.0 is available at |
| // http://www.opensource.org/licenses/apache2.0.php |
| // |
| // You may elect to redistribute this code under either of these licenses. |
| // ======================================================================== |
| // |
| |
| package org.eclipse.jetty.util.statistic; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| import org.eclipse.jetty.util.Atomics; |
| |
| |
| /* ------------------------------------------------------------ */ |
| /** Statistics on a counter value. |
| * <p> |
| * Keep total, current and maximum values of a counter that |
| * can be incremented and decremented. The total refers only |
| * to increments. |
| * |
| */ |
| public class CounterStatistic |
| { |
| protected final AtomicLong _max = new AtomicLong(); |
| protected final AtomicLong _curr = new AtomicLong(); |
| protected final AtomicLong _total = new AtomicLong(); |
| |
| /* ------------------------------------------------------------ */ |
| public void reset() |
| { |
| reset(0); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| public void reset(final long value) |
| { |
| _max.set(value); |
| _curr.set(value); |
| _total.set(0); // total always set to 0 to properly calculate cumulative total |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @param delta the amount to add to the count |
| */ |
| public void add(final long delta) |
| { |
| long value=_curr.addAndGet(delta); |
| if (delta > 0) |
| _total.addAndGet(delta); |
| Atomics.updateMax(_max,value); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @param delta the amount to subtract the count by. |
| */ |
| public void subtract(final long delta) |
| { |
| add(-delta); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| */ |
| public void increment() |
| { |
| add(1); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| */ |
| public void decrement() |
| { |
| add(-1); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @return max value |
| */ |
| public long getMax() |
| { |
| return _max.get(); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @return current value |
| */ |
| public long getCurrent() |
| { |
| return _curr.get(); |
| } |
| |
| /* ------------------------------------------------------------ */ |
| /** |
| * @return total value |
| */ |
| public long getTotal() |
| { |
| return _total.get(); |
| } |
| } |