/*
* Druid - a distributed column store.
* Copyright (C) 2012, 2013 Metamarkets Group Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package io.druid.query;
import com.google.common.base.Function;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;
import com.metamx.common.ISE;
import com.metamx.common.guava.Sequence;
import com.metamx.common.guava.Sequences;
import io.druid.query.aggregation.MetricManipulationFn;
import io.druid.query.aggregation.MetricManipulatorFns;
import javax.annotation.Nullable;
import java.util.List;
import java.util.Map;
/**
*/
public class FinalizeResultsQueryRunner<T> implements QueryRunner<T>
{
private final QueryRunner<T> baseRunner;
private final QueryToolChest<T, Query<T>> toolChest;
public FinalizeResultsQueryRunner(
QueryRunner<T> baseRunner,
QueryToolChest<T, Query<T>> toolChest
)
{
this.baseRunner = baseRunner;
this.toolChest = toolChest;
}
@Override
public Sequence<T> run(final Query<T> query, Map<String, Object> context)
{
final boolean isBySegment = query.getContextBySegment(false);
final boolean shouldFinalize = query.getContextFinalize(true);
final Query<T> queryToRun;
final Function<T, T> finalizerFn;
final MetricManipulationFn metricManipulationFn;
if (shouldFinalize) {
queryToRun = query.withOverriddenContext(ImmutableMap.<String, Object>of("finalize", false));
metricManipulationFn = MetricManipulatorFns.finalizing();
} else {
queryToRun = query;
metricManipulationFn = MetricManipulatorFns.identity();
}
if (isBySegment) {
finalizerFn = new Function<T, T>()
{
final Function<T, T> baseFinalizer = toolChest.makePostComputeManipulatorFn(
query,
metricManipulationFn
);
@Override
@SuppressWarnings("unchecked")
public T apply(T input)
{
Result<BySegmentResultValueClass<T>> result = (Result<BySegmentResultValueClass<T>>) input;
if (input == null) {
throw new ISE("Cannot have a null result!");
}
BySegmentResultValue<T> resultsClass = result.getValue();
return (T) new Result<BySegmentResultValueClass>(
result.getTimestamp(),
new BySegmentResultValueClass(
Lists.transform(resultsClass.getResults(), baseFinalizer),
resultsClass.getSegmentId(),
resultsClass.getInterval()
)
);
}
};
} else {
finalizerFn = toolChest.makePostComputeManipulatorFn(query, metricManipulationFn);
}
return Sequences.map(
baseRunner.run(queryToRun, context),
finalizerFn
);
}
}