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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.
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package org.elasticsearch.search.aggregations.pipeline.bucketmetrics;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.InternalAggregation.ReduceContext;
import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
import org.elasticsearch.search.aggregations.pipeline.BucketHelpers;
import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import org.elasticsearch.search.aggregations.pipeline.SiblingPipelineAggregator;
import org.elasticsearch.search.aggregations.support.AggregationPath;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.Map;
/**
* A class of sibling pipeline aggregations which calculate metrics across the
* buckets of a sibling aggregation
*/
public abstract class BucketMetricsPipelineAggregator extends SiblingPipelineAggregator {
protected final DocValueFormat format;
protected final GapPolicy gapPolicy;
protected BucketMetricsPipelineAggregator(String name, String[] bucketsPaths, GapPolicy gapPolicy, DocValueFormat format,
Map<String, Object> metaData) {
super(name, bucketsPaths, metaData);
this.gapPolicy = gapPolicy;
this.format = format;
}
/**
* Read from a stream.
*/
protected BucketMetricsPipelineAggregator(StreamInput in) throws IOException {
super(in);
format = in.readNamedWriteable(DocValueFormat.class);
gapPolicy = GapPolicy.readFrom(in);
}
@Override
public final void doWriteTo(StreamOutput out) throws IOException {
out.writeNamedWriteable(format);
gapPolicy.writeTo(out);
innerWriteTo(out);
}
protected void innerWriteTo(StreamOutput out) throws IOException {
}
@Override
public final InternalAggregation doReduce(Aggregations aggregations, ReduceContext context) {
preCollection();
List<String> bucketsPath = AggregationPath.parse(bucketsPaths()[0]).getPathElementsAsStringList();
for (Aggregation aggregation : aggregations) {
if (aggregation.getName().equals(bucketsPath.get(0))) {
bucketsPath = bucketsPath.subList(1, bucketsPath.size());
InternalMultiBucketAggregation<?, ?> multiBucketsAgg = (InternalMultiBucketAggregation<?, ?>) aggregation;
List<? extends InternalMultiBucketAggregation.InternalBucket> buckets = multiBucketsAgg.getBuckets();
for (InternalMultiBucketAggregation.InternalBucket bucket : buckets) {
Double bucketValue = BucketHelpers.resolveBucketValue(multiBucketsAgg, bucket, bucketsPath, gapPolicy);
if (bucketValue != null && !Double.isNaN(bucketValue)) {
collectBucketValue(bucket.getKeyAsString(), bucketValue);
}
}
}
}
return buildAggregation(Collections.emptyList(), metaData());
}
/**
* Called before initial collection and between successive collection runs.
* A chance to initialize or re-initialize state
*/
protected void preCollection() {
}
/**
* Called after a collection run is finished to build the aggregation for
* the collected state.
*
* @param pipelineAggregators
* the pipeline aggregators to add to the resulting aggregation
* @param metadata
* the metadata to add to the resulting aggregation
*/
protected abstract InternalAggregation buildAggregation(List<PipelineAggregator> pipelineAggregators, Map<String, Object> metadata);
/**
* Called for each bucket with a value so the state can be modified based on
* the key and metric value for this bucket
*
* @param bucketKey
* the key for this bucket as a String
* @param bucketValue
* the value of the metric specified in <code>bucketsPath</code>
* for this bucket
*/
protected abstract void collectBucketValue(String bucketKey, Double bucketValue);
}