/*

 * Copyright (c) 2008, 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

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 */

package sun.nio.ch;

import java.net.InetAddress;

import java.net.NetworkInterface;

import java.io.IOException;

import java.nio.channels.MembershipKey;

import java.nio.channels.MulticastChannel;

import java.util.HashSet;

/**

 * MembershipKey implementation.

 */

class MembershipKeyImpl

    extends MembershipKey

{

    private final MulticastChannel ch;

    private final InetAddress group;

    private final NetworkInterface interf;

    private final InetAddress source;

    private volatile boolean invalid;

    // lock used when creating or accessing blockedSet

    private final Object stateLock = new Object();

    // set of source addresses that are blocked

    private HashSet<InetAddress> blockedSet;

    private MembershipKeyImpl(MulticastChannel ch,

                              InetAddress group,

                              NetworkInterface interf,

                              InetAddress source)

    {

        this.ch = ch;

        this.group = group;

        this.interf = interf;

        this.source = source;

    }

    /**

     * MembershipKey will additional context for IPv4 membership

     */

    static class Type4 extends MembershipKeyImpl {

        private final int groupAddress;

        private final int interfAddress;

        private final int sourceAddress;

        Type4(MulticastChannel ch,

              InetAddress group,

              NetworkInterface interf,

              InetAddress source,

              int groupAddress,

              int interfAddress,

              int sourceAddress)

        {

            super(ch, group, interf, source);

            this.groupAddress = groupAddress;

            this.interfAddress = interfAddress;

            this.sourceAddress = sourceAddress;

        }

        int groupAddress() {

            return groupAddress;

        }

        int interfaceAddress() {

            return interfAddress;

        }

        int source() {

            return sourceAddress;

        }

    }

    /**

     * MembershipKey will additional context for IPv6 membership

     */

    static class Type6 extends MembershipKeyImpl {

        private final byte[] groupAddress;

        private final int index;

        private final byte[] sourceAddress;

        Type6(MulticastChannel ch,

              InetAddress group,

              NetworkInterface interf,

              InetAddress source,

              byte[] groupAddress,

              int index,

              byte[] sourceAddress)

        {

            super(ch, group, interf, source);

            this.groupAddress = groupAddress;

            this.index = index;

            this.sourceAddress = sourceAddress;

        }

        byte[] groupAddress() {

            return groupAddress;

        }

        int index() {

            return index;

        }

        byte[] source() {

            return sourceAddress;

        }

    }

    public boolean isValid() {

        return !invalid;

    }

    // package-private

    void invalidate() {

        invalid = true;

    }

    public void drop() {

        // delegate to channel

        ((DatagramChannelImpl)ch).drop(this);

    }

    @Override

    public MulticastChannel channel() {

        return ch;

    }

    @Override

    public InetAddress group() {

        return group;

    }

    @Override

    public NetworkInterface networkInterface() {

        return interf;

    }

    @Override

    public InetAddress sourceAddress() {

        return source;

    }

    @Override

    public MembershipKey block(InetAddress toBlock)

        throws IOException

    {

        if (source != null)

            throw new IllegalStateException("key is source-specific");

        synchronized (stateLock) {

            if ((blockedSet != null) && blockedSet.contains(toBlock)) {

                // already blocked, nothing to do

                return this;

            }

            ((DatagramChannelImpl)ch).block(this, toBlock);

            // created blocked set if required and add source address

            if (blockedSet == null)

                blockedSet = new HashSet<>();

            blockedSet.add(toBlock);

        }

        return this;

    }

    @Override

    public MembershipKey unblock(InetAddress toUnblock) {

        synchronized (stateLock) {

            if ((blockedSet == null) || !blockedSet.contains(toUnblock))

                throw new IllegalStateException("not blocked");

            ((DatagramChannelImpl)ch).unblock(this, toUnblock);

            blockedSet.remove(toUnblock);

        }

        return this;

    }

    @Override

    public String toString() {

        StringBuilder sb = new StringBuilder(64);

        sb.append('<');

        sb.append(group.getHostAddress());

        sb.append(',');

        sb.append(interf.getName());

        if (source != null) {

            sb.append(',');

            sb.append(source.getHostAddress());

        }

        sb.append('>');

        return sb.toString();

    }

}