io.druid.query.ReferenceCountingSegmentQueryRunner Maven / Gradle / Ivy
/*
* Licensed to Metamarkets Group Inc. (Metamarkets) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Metamarkets licenses this file
* to you 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 io.druid.query;
import io.druid.java.util.common.guava.Sequence;
import io.druid.java.util.common.guava.Sequences;
import io.druid.segment.ReferenceCountingSegment;
import java.util.Map;
/**
*/
public class ReferenceCountingSegmentQueryRunner implements QueryRunner
{
private final QueryRunnerFactory> factory;
private final ReferenceCountingSegment adapter;
private final SegmentDescriptor descriptor;
public ReferenceCountingSegmentQueryRunner(
QueryRunnerFactory> factory,
ReferenceCountingSegment adapter,
SegmentDescriptor descriptor
)
{
this.factory = factory;
this.adapter = adapter;
this.descriptor = descriptor;
}
@Override
public Sequence run(final QueryPlus queryPlus, Map responseContext)
{
if (adapter.increment()) {
try {
final Sequence baseSequence = factory.createRunner(adapter).run(queryPlus, responseContext);
return Sequences.withBaggage(baseSequence, adapter.decrementOnceCloseable());
}
catch (Throwable t) {
try {
adapter.decrement();
}
catch (Exception e) {
t.addSuppressed(e);
}
throw t;
}
} else {
// Segment was closed before we had a chance to increment the reference count
return new ReportTimelineMissingSegmentQueryRunner(descriptor).run(queryPlus, responseContext);
}
}
}