/*
* 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.facebook.presto.execution;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import io.airlift.concurrent.SetThreadName;
import java.util.List;
import java.util.concurrent.Executor;
import static java.util.Objects.requireNonNull;
public class QueuedExecution
{
private final QueryExecution queryExecution;
private final List<QueryQueue> nextQueues;
private final ListenableFuture<?> listenableFuture;
private final Executor executor;
public static QueuedExecution createQueuedExecution(QueryExecution queryExecution, List<QueryQueue> nextQueues, Executor executor)
{
SettableFuture<?> settableFuture = SettableFuture.create();
SqlQueryManager.addCompletionCallback(queryExecution, () -> settableFuture.set(null));
return new QueuedExecution(queryExecution, nextQueues, executor, settableFuture);
}
private QueuedExecution(QueryExecution queryExecution, List<QueryQueue> nextQueues, Executor executor, ListenableFuture<?> listenableFuture)
{
this.queryExecution = requireNonNull(queryExecution, "queryExecution is null");
this.nextQueues = ImmutableList.copyOf(requireNonNull(nextQueues, "nextQueues is null"));
this.executor = requireNonNull(executor, "executor is null");
this.listenableFuture = requireNonNull(listenableFuture, "listenableFuture is null");
}
public ListenableFuture<?> getCompletionFuture()
{
return listenableFuture;
}
public void start()
{
// Only execute if the query is not already completed (e.g. cancelled)
if (listenableFuture.isDone()) {
return;
}
if (nextQueues.isEmpty()) {
executor.execute(() -> {
try (SetThreadName ignored = new SetThreadName("Query-%s", queryExecution.getQueryId())) {
queryExecution.start();
}
});
}
else {
nextQueues.get(0).enqueue(new QueuedExecution(queryExecution, nextQueues.subList(1, nextQueues.size()), executor, listenableFuture));
}
}
}