private List<QueryQueue> getOrCreateQueues(
Session session, Executor executor, List<QueryQueueDefinition> definitions) {
ImmutableList.Builder<QueryQueue> queues = ImmutableList.builder();
for (QueryQueueDefinition definition : definitions) {
String expandedName = definition.getExpandedTemplate(session);
QueueKey key = new QueueKey(definition, expandedName);
if (!queryQueues.containsKey(key)) {
QueryQueue queue =
new QueryQueue(executor, definition.getMaxQueued(), definition.getMaxConcurrent());
if (queryQueues.putIfAbsent(key, queue) == null) {
// Export the mbean, after checking for races
String objectName =
ObjectNames.builder(QueryQueue.class, definition.getTemplate())
.withProperty("expansion", expandedName)
.build();
mbeanExporter.export(objectName, queue);
}
}
queues.add(queryQueues.get(key));
}
return queues.build();
}
private static void checkIsDAG(List<QueryQueueRule> rules) {
DirectedPseudograph<String, DefaultEdge> graph = new DirectedPseudograph<>(DefaultEdge.class);
for (QueryQueueRule rule : rules) {
String lastQueueName = null;
for (QueryQueueDefinition queue : rule.getQueues()) {
String currentQueueName = queue.getTemplate();
graph.addVertex(currentQueueName);
if (lastQueueName != null) {
graph.addEdge(lastQueueName, currentQueueName);
}
lastQueueName = currentQueueName;
}
}
List<String> shortestCycle = shortestCycle(graph);
if (shortestCycle != null) {
String s = Joiner.on(", ").join(shortestCycle);
throw new IllegalArgumentException(
format("Queues must not contain a cycle. The shortest cycle found is [%s]", s));
}
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other == null || getClass() != other.getClass()) {
return false;
}
QueueKey queueKey = (QueueKey) other;
return Objects.equals(name, queueKey.name)
&& Objects.equals(queue.getTemplate(), queueKey.queue.getTemplate());
}
@Override
public int hashCode() {
return Objects.hash(queue.getTemplate(), name);
}