/*

 * Copyright (c) 2016, 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.jfr;

import java.lang.annotation.ElementType;

import java.lang.annotation.Retention;

import java.lang.annotation.RetentionPolicy;

import java.lang.annotation.Target;

/**

 * Annotation that specifies that a method in an event class should be used to

 * filter out events.

 * <p>

 * For the method to be valid it must return a {@code SettingControl} and only have one

 * parameter, which should be a non-abstract subclass of {@link SettingControl}

 * <p>

 * The return value of the method specifies whether the event is to be

 * written to the Flight Recorder system or not.

 * <p>

 * The following example shows how to annotate a method in an event class.

 *

 * <pre>

 * <code>

 * class HelloWorld extend Event {

 *

 *   {@literal @}Label("Message");

 *   String message;

 *

 *   {@literal @}SettingDefinition;

 *   {@literal @}Label("Message Filter");

 *   public boolean filter(RegExpControl regExp) {

 *     return regExp.matches(message);

 *   }

 * }

 * </code>

 * </pre>

 *

 * For an example of how the setting controls are defined, see

 * {@link SettingControl}.

 *

 * @see SettingControl

 *

 * @since 9

 */

@Retention(RetentionPolicy.RUNTIME)

@Target({ ElementType.METHOD })

public @interface SettingDefinition {

}