/*

 * 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.internal.management;

import java.time.Duration;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import jdk.jfr.EventType;

import jdk.jfr.internal.JVMSupport;

import jdk.jfr.internal.LogLevel;

import jdk.jfr.internal.LogTag;

import jdk.jfr.internal.Logger;

import jdk.jfr.internal.MetadataRepository;

import jdk.jfr.internal.Utils;

import jdk.jfr.internal.instrument.JDKEvents;

/**

 * The management API in module jdk.management.jfr should be built on top of the

 * public API in jdk.jfr. Before putting more functionality here, consider if it

 * should not be part of the public API, and if not, please provide motivation

 *

 */

public final class ManagementSupport {

    // Purpose of this method is to expose the event types to the

    // FlightRecorderMXBean without instantiating Flight Recorder.

    //

    // This allows:

    //

    // 1) discoverability, so event settings can be exposed without the need to

    // create a new Recording in FlightrecorderMXBean.

    //

    // 2) a graphical JMX client to list all attributes to the user, without

    // loading JFR memory buffers. This is especially important when there is

    // no intent to use Flight Recorder.

    //

    // An alternative design would be to make FlightRecorder#getEventTypes

    // static, but it would the make the API look strange

    //

    public static List<EventType> getEventTypes() {

        // would normally be checked when a Flight Recorder instance is created

        Utils.checkAccessFlightRecorder();

        if (JVMSupport.isNotAvailable()) {

            return new ArrayList<>();

        }

        JDKEvents.initialize(); // make sure JDK events are available

        return Collections.unmodifiableList(MetadataRepository.getInstance().getRegisteredEventTypes());

    }

    // Reuse internal code for parsing a timespan

    public static long parseTimespan(String s) {

        return Utils.parseTimespan(s);

    }

    // Reuse internal code for formatting settings

    public static final String formatTimespan(Duration dValue, String separation) {

        return Utils.formatTimespan(dValue, separation);

    }

    // Reuse internal logging mechanism

    public static void logError(String message) {

        Logger.log(LogTag.JFR, LogLevel.ERROR, message);

    }

}