| /* |
| * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved. |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0, which is available at |
| * http://www.eclipse.org/legal/epl-2.0. |
| * |
| * This Source Code may also be made available under the following Secondary |
| * Licenses when the conditions for such availability set forth in the |
| * Eclipse Public License v. 2.0 are satisfied: GNU General Public License, |
| * version 2 with the GNU Classpath Exception, which is available at |
| * https://www.gnu.org/software/classpath/license.html. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 |
| */ |
| |
| package com.sun.enterprise.admin.monitor.stats; |
| import org.glassfish.j2ee.statistics.Statistic; |
| import java.io.Serializable; |
| |
| /** |
| * An interface that gives a flexibility to set various values for a particular Statistic. |
| * This provision is basically to have the same data structure to collect and |
| * return the (read-only copy of) statistical data. This extends the |
| * java.io.Serializable, so that its subclasses can be serialized to facilitate |
| * working with other management clients. |
| * Refer to the package description |
| * to understand the intent of this interface. |
| * <P> |
| * Methods of this class should be called judiciously by the component that is |
| * gathering the statistics. |
| * |
| * @author Kedar Mhaswade |
| * @since S1AS8.0 |
| * @version 1.0 |
| */ |
| public interface MutableStatistic extends Serializable { |
| |
| /** |
| * Returns a read-only view of this Statistic. An implementing class has |
| * to return the instances of Statistic interfaces defined in |
| * {@link javax.management.j2ee.statistic} |
| * and {@link com.sun.enterprise.admin.monitor.stats} packages. |
| * |
| * @return an instance of a specific Statistic interface |
| */ |
| Statistic unmodifiableView(); |
| |
| /** |
| * Returns an instance of Statistic whose state can be changed by the caller. It is important |
| * to know that caller should not cache the return value from this method. In general, there |
| * is a problem in this contract in that, a client would not know from a Stats.getCreateCount() |
| * method whether the return value is something that is being modified or is invariant. Hence |
| * the caller should not cache the returned value in a collection and then collectively |
| * process it. The main idea behind providing this method is to control the |
| * number of instances created (per Mahesh's Suggestion). |
| * @return an instance of Statistic interface that should not be cached. |
| */ |
| Statistic modifiableView(); |
| |
| /** |
| * Resets the encapsulated Statistic interface to its initial value. The idea being, if (after |
| * creation of the instance) the state changes, the initial state can be easily regained by |
| * calling this method. Note that the time of last sampling changes to the instant |
| * when this method is invoked. |
| */ |
| void reset(); |
| } |