/*

 * 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 sun.management;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.concurrent.atomic.AtomicInteger;

import sun.misc.Perf;

import sun.management.counter.Units;

import sun.management.counter.Counter;

import sun.management.counter.perf.PerfInstrumentation;

/**

 * A utility class to support the exporting and importing of the address

 * of a connector server using the instrumentation buffer.

 *

 * @since 1.5

 */

public class ConnectorAddressLink {

    private static final String CONNECTOR_ADDRESS_COUNTER =

            "sun.management.JMXConnectorServer.address";

    /*

     * The format of the jvmstat counters representing the properties of

     * a given out-of-the-box JMX remote connector will be as follows:

     *

     * sun.management.JMXConnectorServer.<counter>.<key>=<value>

     *

     * where:

     *

     *     counter = index computed by this class which uniquely identifies

     *               an out-of-the-box JMX remote connector running in this

     *               Java virtual machine.

     *     key/value = a given key/value pair in the map supplied to the

     *                 exportRemote() method.

     *

     * For example,

     *

     * sun.management.JMXConnectorServer.0.remoteAddress=service:jmx:rmi:///jndi/rmi://myhost:5000/jmxrmi

     * sun.management.JMXConnectorServer.0.authenticate=false

     * sun.management.JMXConnectorServer.0.ssl=false

     * sun.management.JMXConnectorServer.0.sslRegistry=false

     * sun.management.JMXConnectorServer.0.sslNeedClientAuth=false

     */

    private static final String REMOTE_CONNECTOR_COUNTER_PREFIX =

            "sun.management.JMXConnectorServer.";

    /*

     * JMX remote connector counter (it will be incremented every

     * time a new out-of-the-box JMX remote connector is created).

     */

    /**

     * Exports the specified connector address to the instrumentation buffer

     * so that it can be read by this or other Java virtual machines running

     * on the same system.

     *

     * @param address The connector address.

     */

    public static void export(String address) {

        if (address == null || address.length() == 0) {

            throw new IllegalArgumentException("address not specified");

        }

        Perf perf = Perf.getPerf();

        perf.createString(

    }

    /**

     * Imports the connector address from the instrument buffer

     * of the specified Java virtual machine.

     *

     * @param vmid an identifier that uniquely identifies a local Java virtual

     * machine, or <code>0</code> to indicate the current Java virtual machine.

     *

     * @return the value of the connector address, or <code>null</code> if the

     * target VM has not exported a connector address.

     *

     * @throws IOException An I/O error occurred while trying to acquire the

     * instrumentation buffer.

     */

    public static String importFrom(int vmid) throws IOException {

        Perf perf = Perf.getPerf();

        ByteBuffer bb;

        try {

            bb = perf.attach(vmid, "r");

        } catch (IllegalArgumentException iae) {

            throw new IOException(iae.getMessage());

        }

        List<Counter> counters =

                new PerfInstrumentation(bb).findByPattern(CONNECTOR_ADDRESS_COUNTER);

        Iterator<Counter> i = counters.iterator();

        if (i.hasNext()) {

            Counter c = i.next();

            return (String) c.getValue();

        } else {

            return null;

        }

    }

    /**

     * Exports the specified remote connector address and associated

     * configuration properties to the instrumentation buffer so that

     * it can be read by this or other Java virtual machines running

     * on the same system.

     *

     * @param properties The remote connector address properties.

     */

    public static void exportRemote(Map<String, String> properties) {

        final int index = counter.getAndIncrement();

        Perf perf = Perf.getPerf();

        for (Map.Entry<String, String> entry : properties.entrySet()) {

            perf.createString(REMOTE_CONNECTOR_COUNTER_PREFIX + index + "." +

                    entry.getKey(), 1, Units.STRING.intValue(), entry.getValue());

        }

    }

    /**

     * Imports the remote connector address and associated

     * configuration properties from the instrument buffer

     * of the specified Java virtual machine.

     *

     * @param vmid an identifier that uniquely identifies a local Java virtual

     * machine, or <code>0</code> to indicate the current Java virtual machine.

     *

     * @return a map containing the remote connector's properties, or an empty

     * map if the target VM has not exported the remote connector's properties.

     *

     * @throws IOException An I/O error occurred while trying to acquire the

     * instrumentation buffer.

     */

    public static Map<String, String> importRemoteFrom(int vmid) throws IOException {

        Perf perf = Perf.getPerf();

        ByteBuffer bb;

        try {

            bb = perf.attach(vmid, "r");

        } catch (IllegalArgumentException iae) {

            throw new IOException(iae.getMessage());

        }

        List<Counter> counters = new PerfInstrumentation(bb).getAllCounters();

        Map<String, String> properties = new HashMap<>();

        for (Counter c : counters) {

            String name =  c.getName();

            if (name.startsWith(REMOTE_CONNECTOR_COUNTER_PREFIX) &&

                    !name.equals(CONNECTOR_ADDRESS_COUNTER)) {

                properties.put(name, c.getValue().toString());

            }

        }

        return properties;

    }

}