private static <C extends Command<R>, R extends Serializable> List<QueueEntry<C, R>> getEntries(
ZNode queueNode, Watcher watcher) {
List<QueueEntry<C, R>> result = Lists.newLinkedList();
List<ZNode> children = queueNode.firstLevelChildren(watcher);
Collections.sort(
children,
new Comparator<ZNode>() {
@Override
public int compare(ZNode first, ZNode second) {
return first.getPath().compareTo(second.getPath());
}
});
for (ZNode child : children) {
QueueEntry<C, R> entry = child.getObject(QueueEntry.class);
child.remove();
result.add(entry);
}
return result;
}
@Override
public void registerNode(
NodeContext nodeContext, Set<Worker> workers, final StatusChangeListener listener)
throws CoordinatorException {
log.info("Going to register node {} with {} workers", nodeContext.getId(), workers.size());
ZNode typeNode = rootNode.child(CoordinationUtil.nodeNameOf(nodeContext.getId().getType()));
ZNode node = typeNode.createChild(znode().withPath(nodeContext.getId().getIdentifier()));
Set<CommandExecutor<?, ?>> executors = Sets.newHashSet();
Set<Qualifier<?>> qualifiers = Sets.newHashSet();
for (Worker worker : workers) {
for (CommandExecutor<?, ?> executor : worker.getExecutors()) {
Qualifier<?> qualifier = executor.getQualifier();
if (qualifiers.contains(qualifier)) {
throw new CoordinatorException(
"Executor for qualifier " + qualifier + " is already registered");
}
executors.add(executor);
}
}
for (CommandExecutor<?, ?> executor : executors) {
registerExecutor(nodeContext, executor, node);
}
rootNode.addNodeWatcher(
new Watcher() {
@Override
public void process(WatchedEvent event) {
if (event.getState() == Event.KeeperState.Disconnected) {
listener.onCoordinatorDisconnected();
}
if (event.getState() == Event.KeeperState.SyncConnected) {
listener.onCoordinatorConnected();
}
}
});
ZNode statuses = rootNode.child(CoordinationUtil.STATUSES_NODE_NAME);
statuses.createChild(znode().ephemeralSequential().withDataObject(nodeContext.getId()));
Lock lock = new ReentrantLock();
lock.lock();
try {
Collection<NodeId> nodeIds = Sets.newHashSet();
StatusWatcher statusWatcher = new StatusWatcher(statuses, lock, nodeIds, listener);
List<ZNode> nodes = statuses.children(statusWatcher);
for (ZNode zNode : nodes) {
nodeIds.add(zNode.getObject(NodeId.class));
}
} finally {
lock.unlock();
}
node.createChild(znode().withPath(CoordinationUtil.AVAILABLE_NODE_NAME));
}
