/*
* Copyright 1999-2011 Alibaba Group.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.dubbo.registry.multicast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MulticastSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import com.alibaba.dubbo.common.utils.ConcurrentHashSet;
import com.alibaba.dubbo.common.utils.NamedThreadFactory;
import com.alibaba.dubbo.common.utils.NetUtils;
import com.alibaba.dubbo.common.utils.StringUtils;
import com.alibaba.dubbo.common.utils.UrlUtils;
import com.alibaba.dubbo.registry.NotifyListener;
import com.alibaba.dubbo.registry.support.FailbackRegistry;
/**
* MulticastRegistry
*
* @author william.liangf
*/
public class MulticastRegistry extends FailbackRegistry {
// 日志输出
private static final Logger logger = LoggerFactory.getLogger(MulticastRegistry.class);
private static final int DEFAULT_MULTICAST_PORT = 1234;
private final InetAddress mutilcastAddress;
private final MulticastSocket mutilcastSocket;
private final int mutilcastPort;
private final ConcurrentMap<URL, Set<URL>> received = new ConcurrentHashMap<URL, Set<URL>>();
private final ScheduledExecutorService cleanExecutor = Executors.newScheduledThreadPool(1, new NamedThreadFactory("DubboMulticastRegistryCleanTimer", true));
private final ScheduledFuture<?> cleanFuture;
private final int cleanPeriod;
private volatile boolean admin = false;
public MulticastRegistry(URL url) {
super(url);
if (url.isAnyHost()) {
throw new IllegalStateException("registry address == null");
}
if (! isMulticastAddress(url.getHost())) {
throw new IllegalArgumentException("Invalid multicast address " + url.getHost() + ", scope: 224.0.0.0 - 239.255.255.255");
}
try {
mutilcastAddress = InetAddress.getByName(url.getHost());
mutilcastPort = url.getPort() <= 0 ? DEFAULT_MULTICAST_PORT : url.getPort();
mutilcastSocket = new MulticastSocket(mutilcastPort);
mutilcastSocket.setLoopbackMode(false);
mutilcastSocket.joinGroup(mutilcastAddress);
Thread thread = new Thread(new Runnable() {
public void run() {
byte[] buf = new byte[2048];
DatagramPacket recv = new DatagramPacket(buf, buf.length);
while (! mutilcastSocket.isClosed()) {
try {
mutilcastSocket.receive(recv);
String msg = new String(recv.getData()).trim();
int i = msg.indexOf('\n');
if (i > 0) {
msg = msg.substring(0, i).trim();
}
MulticastRegistry.this.receive(msg, (InetSocketAddress) recv.getSocketAddress());
Arrays.fill(buf, (byte)0);
} catch (Throwable e) {
if (! mutilcastSocket.isClosed()) {
logger.error(e.getMessage(), e);
}
}
}
}
}, "DubboMulticastRegistryReceiver");
thread.setDaemon(true);
thread.start();
} catch (IOException e) {
throw new IllegalStateException(e.getMessage(), e);
}
this.cleanPeriod = url.getParameter(Constants.SESSION_TIMEOUT_KEY, Constants.DEFAULT_SESSION_TIMEOUT);
if (url.getParameter("clean", true)) {
this.cleanFuture = cleanExecutor.scheduleWithFixedDelay(new Runnable() {
public void run() {
try {
clean(); // 清除过期者
} catch (Throwable t) { // 防御性容错
logger.error("Unexpected exception occur at clean expired provider, cause: " + t.getMessage(), t);
}
}
}, cleanPeriod, cleanPeriod, TimeUnit.MILLISECONDS);
} else {
this.cleanFuture = null;
}
}
private static boolean isMulticastAddress(String ip) {
int i = ip.indexOf('.');
if (i > 0) {
String prefix = ip.substring(0, i);
if (StringUtils.isInteger(prefix)) {
int p = Integer.parseInt(prefix);
return p >= 224 && p <= 239;
}
}
return false;
}
private void clean() {
if (admin) {
for (Set<URL> providers : new HashSet<Set<URL>>(received.values())) {
for (URL url : new HashSet<URL>(providers)) {
if (isExpired(url)) {
if (logger.isWarnEnabled()) {
logger.warn("Clean expired provider " + url);
}
doUnregister(url);
}
}
}
}
}
private boolean isExpired(URL url) {
if (! url.getParameter(Constants.DYNAMIC_KEY, true)
|| url.getPort() <= 0
|| Constants.CONSUMER_PROTOCOL.equals(url.getProtocol())
|| Constants.ROUTE_PROTOCOL.equals(url.getProtocol())
|| Constants.OVERRIDE_PROTOCOL.equals(url.getProtocol())) {
return false;
}
Socket socket = null;
try {
socket = new Socket(url.getHost(), url.getPort());
} catch (Throwable e) {
try {
Thread.sleep(100);
} catch (Throwable e2) {
}
Socket socket2 = null;
try {
socket2 = new Socket(url.getHost(), url.getPort());
} catch (Throwable e2) {
return true;
} finally {
if (socket2 != null) {
try {
socket2.close();
} catch (Throwable e2) {
}
}
}
} finally {
if (socket != null) {
try {
socket.close();
} catch (Throwable e) {
}
}
}
return false;
}
private void receive(String msg, InetSocketAddress remoteAddress) {
if (logger.isInfoEnabled()) {
logger.info("Receive multicast message: " + msg + " from " + remoteAddress);
}
if (msg.startsWith(Constants.REGISTER)) {
URL url = URL.valueOf(msg.substring(Constants.REGISTER.length()).trim());
registered(url);
} else if (msg.startsWith(Constants.UNREGISTER)) {
URL url = URL.valueOf(msg.substring(Constants.UNREGISTER.length()).trim());
unregistered(url);
} else if (msg.startsWith(Constants.SUBSCRIBE)) {
URL url = URL.valueOf(msg.substring(Constants.SUBSCRIBE.length()).trim());
Set<URL> urls = getRegistered();
if (urls != null && urls.size() > 0) {
for (URL u : urls) {
if (UrlUtils.isMatch(url, u)) {
String host = remoteAddress != null && remoteAddress.getAddress() != null
? remoteAddress.getAddress().getHostAddress() : url.getIp();
if (url.getParameter("unicast", true) // 消费者的机器是否只有一个进程
&& ! NetUtils.getLocalHost().equals(host)) { // 同机器多进程不能用unicast单播信息，否则只会有一个进程收到信息
unicast(Constants.REGISTER + " " + u.toFullString(), host);
} else {
broadcast(Constants.REGISTER + " " + u.toFullString());
}
}
}
}
}/* else if (msg.startsWith(UNSUBSCRIBE)) {
}*/
}
private void broadcast(String msg) {
if (logger.isInfoEnabled()) {
logger.info("Send broadcast message: " + msg + " to " + mutilcastAddress + ":" + mutilcastPort);
}
try {
byte[] data = (msg + "\n").getBytes();
DatagramPacket hi = new DatagramPacket(data, data.length, mutilcastAddress, mutilcastPort);
mutilcastSocket.send(hi);
} catch (Exception e) {
throw new IllegalStateException(e.getMessage(), e);
}
}
private void unicast(String msg, String host) {
if (logger.isInfoEnabled()) {
logger.info("Send unicast message: " + msg + " to " + host + ":" + mutilcastPort);
}
try {
byte[] data = (msg + "\n").getBytes();
DatagramPacket hi = new DatagramPacket(data, data.length, InetAddress.getByName(host), mutilcastPort);
mutilcastSocket.send(hi);
} catch (Exception e) {
throw new IllegalStateException(e.getMessage(), e);
}
}
protected void doRegister(URL url) {
broadcast(Constants.REGISTER + " " + url.toFullString());
}
protected void doUnregister(URL url) {
broadcast(Constants.UNREGISTER + " " + url.toFullString());
}
protected void doSubscribe(URL url, NotifyListener listener) {
if (Constants.ANY_VALUE.equals(url.getServiceInterface())) {
admin = true;
}
broadcast(Constants.SUBSCRIBE + " " + url.toFullString());
synchronized (listener) {
try {
listener.wait(url.getParameter(Constants.TIMEOUT_KEY, Constants.DEFAULT_TIMEOUT));
} catch (InterruptedException e) {
}
}
}
protected void doUnsubscribe(URL url, NotifyListener listener) {
if (! Constants.ANY_VALUE.equals(url.getServiceInterface())
&& url.getParameter(Constants.REGISTER_KEY, true)) {
unregister(url);
}
broadcast(Constants.UNSUBSCRIBE + " " + url.toFullString());
}
public boolean isAvailable() {
try {
return mutilcastSocket != null;
} catch (Throwable t) {
return false;
}
}
public void destroy() {
super.destroy();
try {
if (cleanFuture != null) {
cleanFuture.cancel(true);
}
} catch (Throwable t) {
logger.warn(t.getMessage(), t);
}
try {
mutilcastSocket.leaveGroup(mutilcastAddress);
mutilcastSocket.close();
} catch (Throwable t) {
logger.warn(t.getMessage(), t);
}
}
protected void registered(URL url) {
for (Map.Entry<URL, Set<NotifyListener>> entry : getSubscribed().entrySet()) {
URL key = entry.getKey();
if (UrlUtils.isMatch(key, url)) {
Set<URL> urls = received.get(key);
if (urls == null) {
received.putIfAbsent(key, new ConcurrentHashSet<URL>());
urls = received.get(key);
}
urls.add(url);
List<URL> list = toList(urls);
for (NotifyListener listener : entry.getValue()) {
notify(key, listener, list);
synchronized (listener) {
listener.notify();
}
}
}
}
}
protected void unregistered(URL url) {
for (Map.Entry<URL, Set<NotifyListener>> entry : getSubscribed().entrySet()) {
URL key = entry.getKey();
if (UrlUtils.isMatch(key, url)) {
Set<URL> urls = received.get(key);
if (urls != null) {
urls.remove(url);
}
List<URL> list = toList(urls);
for (NotifyListener listener : entry.getValue()) {
notify(key, listener, list);
}
}
}
}
protected void subscribed(URL url, NotifyListener listener) {
List<URL> urls = lookup(url);
notify(url, listener, urls);
}
private List<URL> toList(Set<URL> urls) {
List<URL> list = new ArrayList<URL>();
if (urls != null && urls.size() > 0) {
for (URL url : urls) {
list.add(url);
}
}
return list;
}
public void register(URL url) {
super.register(url);
registered(url);
}
public void unregister(URL url) {
super.unregister(url);
unregistered(url);
}
public void subscribe(URL url, NotifyListener listener) {
super.subscribe(url, listener);
subscribed(url, listener);
}
public void unsubscribe(URL url, NotifyListener listener) {
super.unsubscribe(url, listener);
received.remove(url);
}
public List<URL> lookup(URL url) {
List<URL> urls= new ArrayList<URL>();
Map<String, List<URL>> notifiedUrls = getNotified().get(url);
if (notifiedUrls != null && notifiedUrls.size() > 0) {
for (List<URL> values : notifiedUrls.values()) {
urls.addAll(values);
}
}
if (urls == null || urls.size() == 0) {
List<URL> cacheUrls = getCacheUrls(url);
if (cacheUrls != null && cacheUrls.size() > 0) {
urls.addAll(cacheUrls);
}
}
if (urls == null || urls.size() == 0) {
for (URL u: getRegistered()) {
if (UrlUtils.isMatch(url, u)) {
urls.add(u);
}
}
}
if (Constants.ANY_VALUE.equals(url.getServiceInterface())) {
for (URL u: getSubscribed().keySet()) {
if (UrlUtils.isMatch(url, u)) {
urls.add(u);
}
}
}
return urls;
}
public MulticastSocket getMutilcastSocket() {
return mutilcastSocket;
}
public Map<URL, Set<URL>> getReceived() {
return received;
}
}