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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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 org.elasticsearch.search.aggregations.bucket.global;
import org.apache.lucene.index.LeafReaderContext;
import org.elasticsearch.search.aggregations.AggregationExecutionException;
import org.elasticsearch.search.aggregations.Aggregator;
import org.elasticsearch.search.aggregations.AggregatorFactories;
import org.elasticsearch.search.aggregations.AggregatorFactory;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.LeafBucketCollector;
import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import org.elasticsearch.search.aggregations.support.AggregationContext;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/**
*
*/
public class GlobalAggregator extends SingleBucketAggregator {
public GlobalAggregator(String name, AggregatorFactories subFactories, AggregationContext aggregationContext, List<PipelineAggregator> pipelineAggregators,
Map<String, Object> metaData) throws IOException {
super(name, subFactories, aggregationContext, null, pipelineAggregators, metaData);
}
@Override
public LeafBucketCollector getLeafCollector(LeafReaderContext ctx,
final LeafBucketCollector sub) throws IOException {
return new LeafBucketCollectorBase(sub, null) {
@Override
public void collect(int doc, long bucket) throws IOException {
assert bucket == 0 : "global aggregator can only be a top level aggregator";
collectBucket(sub, doc, bucket);
}
};
}
@Override
public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
assert owningBucketOrdinal == 0 : "global aggregator can only be a top level aggregator";
return new InternalGlobal(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), pipelineAggregators(),
metaData());
}
@Override
public InternalAggregation buildEmptyAggregation() {
throw new UnsupportedOperationException("global aggregations cannot serve as sub-aggregations, hence should never be called on #buildEmptyAggregations");
}
public static class Factory extends AggregatorFactory {
public Factory(String name) {
super(name, InternalGlobal.TYPE.name());
}
@Override
public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
if (parent != null) {
throw new AggregationExecutionException("Aggregation [" + parent.name() + "] cannot have a global " +
"sub-aggregation [" + name + "]. Global aggregations can only be defined as top level aggregations");
}
if (collectsFromSingleBucket == false) {
throw new IllegalStateException();
}
return new GlobalAggregator(name, factories, context, pipelineAggregators, metaData);
}
}
}