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/*
* Copyright (c) 2008, 2009, 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 sun.nio.ch;
import java.nio.channels.*;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.*;
/**
* Simple registry of membership keys for a MulticastChannel.
*
* Instances of this object are not safe by multiple concurrent threads.
*/
class MembershipRegistry {
// map multicast group to keys
private Map<InetAddress,List<MembershipKeyImpl>> groups = null;
MembershipRegistry() {
}
/**
* Checks registry for membership of the group on the given
* network interface.
*/
MembershipKey checkMembership(InetAddress group, NetworkInterface interf,
InetAddress source)
{
if (groups != null) {
List<MembershipKeyImpl> keys = groups.get(group);
if (keys != null) {
for (MembershipKeyImpl key: keys) {
if (key.networkInterface().equals(interf)) {
// already a member to receive all packets so return
// existing key or detect conflict
if (source == null) {
if (key.sourceAddress() == null)
return key;
throw new IllegalStateException("Already a member to receive all packets");
}
// already have source-specific membership so return key
// or detect conflict
if (key.sourceAddress() == null)
throw new IllegalStateException("Already have source-specific membership");
if (source.equals(key.sourceAddress()))
return key;
}
}
}
}
return null;
}
/**
* Add membership to the registry, returning a new membership key.
*/
void add(MembershipKeyImpl key) {
InetAddress group = key.group();
List<MembershipKeyImpl> keys;
if (groups == null) {
groups = new HashMap<InetAddress,List<MembershipKeyImpl>>();
keys = null;
} else {
keys = groups.get(group);
}
if (keys == null) {
keys = new LinkedList<MembershipKeyImpl>();
groups.put(group, keys);
}
keys.add(key);
}
/**
* Remove a key from the registry
*/
void remove(MembershipKeyImpl key) {
InetAddress group = key.group();
List<MembershipKeyImpl> keys = groups.get(group);
if (keys != null) {
Iterator<MembershipKeyImpl> i = keys.iterator();
while (i.hasNext()) {
if (i.next() == key) {
i.remove();
break;
}
}
if (keys.isEmpty()) {
groups.remove(group);
}
}
}
/**
* Invalidate all keys in the registry
*/
void invalidateAll() {
if (groups != null) {
for (InetAddress group: groups.keySet()) {
for (MembershipKeyImpl key: groups.get(group)) {
key.invalidate();
}
}
}
}
}
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