/*

 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

 * 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

package jdk.internal.event;

/**

 * Base class for events, to be subclassed in order to define events and their

 * fields.

 */

public abstract class Event {

    /**

     * Sole constructor, for invocation by subclass constructors, typically

     * implicit.

     */

    protected Event() {

    }

    /**

     * Starts the timing of this event.

     */

    public void begin() {

    }

    /**

     * Ends the timing of this event.

     *

     * The {@code end} method must be invoked after the {@code begin} method.

     */

    public void end() {

    }

    /**

     * Writes the field values, time stamp, and event duration.

     * <p>

     * If the event starts with an invocation of the {@code begin} method, but does

     * not end with an explicit invocation of the {@code end} method, then the event

     * ends when the {@code commit} method is invoked.

     */

    public void commit() {

    }

    /**

     * Returns {@code true} if the event is enabled, {@code false} otherwise

     *

     * @return {@code true} if event is enabled, {@code false} otherwise

     */

    public boolean isEnabled() {

        return false;

    }

    /**

     * Returns {@code true} if the event is enabled and if the duration is within

     * the threshold for the event, {@code false} otherwise.

     *

     * @return {@code true} if the event can be written, {@code false} otherwise

     */

    public boolean shouldCommit() {

        return false;

    }

    /**

     * Sets a field value.

     *

     * @param index the index of the field to set

     * @param value value to set, can be {@code null}

     * @throws UnsupportedOperationException if functionality is not supported

     * @throws IndexOutOfBoundsException if {@code index} is less than {@code 0} or

     *         greater than or equal to the number of fields specified for the event

     */

    public void set(int index, Object value) {

    }

}