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 * 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

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 */

package jdk.jfr;

import java.time.Duration;

import java.util.Map;

/**

 * Convenience class for applying event settings to a recording.

 * <p>

 * An {@code EventSettings} object for a recording can be obtained by invoking

 * the {@link Recording#enable(String)} method which is configured using method

 * chaining.

 * <p>

 * The following example shows how to use the {@code EventSettings} class.

 * <pre>

 * {@code

 * Recording r = new Recording();

 * r.enable("jdk.CPULoad")

 *    .withPeriod(Duration.ofSeconds(1));

 * r.enable("jdk.FileWrite")

 *    .withoutStackTrace()

 *    .withThreshold(Duration.ofNanos(10));

 * r.start();

 * Thread.sleep(10_000);

 * r.stop();

 * r.dump(Files.createTempFile("recording", ".jfr"));

 *

 * }

 * </pre>

 * @since 9

 */

public abstract class EventSettings {

    // package private

    EventSettings() {

    }

    /**

     * Enables stack traces for the event that is associated with this event setting.

     * <p>

     * Equivalent to invoking the {@code with("stackTrace", "true")} method.

     *

     * @return event settings object for further configuration, not {@code null}

     */

    final public EventSettings withStackTrace() {

        return with(StackTrace.NAME, "true");

    }

    /**

     * Disables stack traces for the event that is associated with this event setting.

     * <p>

     * Equivalent to invoking the {@code with("stackTrace", "false")} method.

     *

     * @return event settings object for further configuration, not {@code null}

     */

    final public EventSettings withoutStackTrace() {

        return with(StackTrace.NAME, "false");

    }

    /**

     * Specifies that a threshold is not used.

     * <p>

     * This is a convenience method, equivalent to invoking the

     * {@code with("threshold", "0 s")} method.

     *

     * @return event settings object for further configuration, not {@code null}

     */

    final public EventSettings withoutThreshold() {

        return with(Threshold.NAME, "0 s");

    }

    /**

     * Sets the interval for the event that is associated with this event setting.

     *

     * @param duration the duration, not {@code null}

     *

     * @return event settings object for further configuration, not {@code null}

     */

    final public EventSettings withPeriod(Duration duration) {

        return with(Period.NAME, duration.toNanos() + " ns");

    }

    /**

     * Sets the threshold for the event that is associated with this event setting.

     *

     * @param duration the duration, or {@code null} if no duration is used

     *

     * @return event settings object for further configuration, not {@code null}

     */

    final public EventSettings withThreshold(Duration duration) {

        if (duration == null) {

            return with(Threshold.NAME, "0 ns");

        } else {

            return with(Threshold.NAME, duration.toNanos() + " ns");

        }

    }

    /**

     * Sets a setting value for the event that is associated with this event setting.

     *

     * @param name the name of the setting (for example, {@code "threshold"})

     *

     * @param value the value to set (for example {@code "20 ms"} not

     *        {@code null})

     *

     * @return event settings object for further configuration, not {@code null}

     */

    abstract public EventSettings with(String name, String value);

    /**

     * Creates a settings {@code Map} for the event that is associated with this

     * event setting.

     *

     * @return a settings {@code Map}, not {@code null}

     */

    abstract Map<String, String> toMap();

}