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package com.orbekk.same;
import java.util.ArrayList;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.orbekk.same.State.Component;
public class MasterServiceImpl implements MasterService, Runnable {
private Logger logger = LoggerFactory.getLogger(getClass());
private final ConnectionManager connections;
private State state;
private boolean stopped = false;
private Broadcaster broadcaster;
private List<String> _fullStateReceivers = new ArrayList<String>();
private Thread workerThread = null;
public static MasterServiceImpl create(ConnectionManager connections,
Broadcaster broadcaster, String myUrl) {
State state = new State("DefaultMaster");
state.update(".masterUrl", myUrl, 1);
return new MasterServiceImpl(state, connections, broadcaster);
}
/** Constructor for internal use.
*/
MasterServiceImpl(State initialState, ConnectionManager connections,
Broadcaster broadcaster) {
this.state = initialState;
this.connections = connections;
this.broadcaster = broadcaster;
}
@Override
public synchronized void joinNetworkRequest(String clientUrl) {
logger.info("JoinNetworkRequest({})", clientUrl);
List<String> participants = participants();
if (!participants.contains(clientUrl)) {
participants.add(clientUrl);
_fullStateReceivers.add(clientUrl);
state.updateFromObject(".participants", participants,
state.getRevision(".participants") + 1);
notifyAll();
} else {
logger.warn("Client {} already part of network. " +
"Ignoring participation request", clientUrl);
}
}
boolean _sendUpdatedComponents() {
boolean worked = false;
for (final Component component : state.getAndClearUpdatedComponents()) {
logger.info("Broadcasting new component {}", component);
broadcastNewComponents(participants(), listWrap(component));
worked = true;
}
return worked;
}
private <T>List<T> listWrap(T o) {
List<T> list = new ArrayList<T>();
list.add(o);
return list;
}
synchronized boolean _sendFullState() {
boolean hasWork = _fullStateReceivers.size() != 0;
if (hasWork) {
logger.info("Sending full state to new participants.");
final List<State.Component> components = state.getComponents();
broadcastNewComponents(_fullStateReceivers, components);
_fullStateReceivers.clear();
}
return hasWork;
}
private synchronized void removeParticipant(String url) {
List<String> participants = participants();
if (participants.contains(url)) {
logger.warn("RemoveParticipant({})", url);
participants.remove(url);
state.updateFromObject(".participants", participants,
state.getRevision(".participants") + 1);
notifyAll();
}
}
private void broadcastNewComponents(List<String> destinations,
final List<State.Component> components) {
broadcaster.broadcast(destinations, new ServiceOperation() {
@Override public void run(String url) {
ClientService client = connections.getClient(url);
try {
for (Component c : components) {
client.setState(c.getName(), c.getData(),
c.getRevision());
}
} catch (Exception e) {
logger.info("Client {} failed to receive state update.", url);
removeParticipant(url);
}
}
});
}
private List<String> participants() {
return state.getList(".participants");
}
@Override
public synchronized boolean updateStateRequest(String component,
String newData, long revision) {
boolean updated = state.update(component, newData, revision + 1);
if (updated) {
notifyAll();
}
return updated;
}
boolean _performWork() {
boolean worked = false;
worked |= _sendUpdatedComponents();
worked |= _sendFullState();
return worked;
}
@Override
public void run() {
while (!stopped) {
if (!_performWork()) {
synchronized (this) {
try {
wait(500);
} catch (InterruptedException e) {
stopped = true;
}
}
}
if (Thread.interrupted()) {
stopped = true;
}
}
}
public void start() {
if (workerThread == null) {
workerThread = new Thread(this);
workerThread.start();
logger.info("Master thread started. {}", state);
}
}
public void join() throws InterruptedException {
workerThread.join();
}
public void interrupt() {
workerThread.interrupt();
}
}
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