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* 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
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package org.elasticsearch.search.aggregations.pipeline.derivative;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.search.aggregations.AggregationExecutionException;
import org.elasticsearch.search.aggregations.AggregatorFactory;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.InternalAggregation.ReduceContext;
import org.elasticsearch.search.aggregations.InternalAggregation.Type;
import org.elasticsearch.search.aggregations.InternalAggregations;
import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregator;
import org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogram;
import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorFactory;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorStreams;
import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
import org.joda.time.DateTime;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import static org.elasticsearch.common.util.CollectionUtils.eagerTransform;
import static org.elasticsearch.search.aggregations.pipeline.BucketHelpers.resolveBucketValue;
public class DerivativePipelineAggregator extends PipelineAggregator {
public final static Type TYPE = new Type("derivative");
public final static PipelineAggregatorStreams.Stream STREAM = new PipelineAggregatorStreams.Stream() {
@Override
public DerivativePipelineAggregator readResult(StreamInput in) throws IOException {
DerivativePipelineAggregator result = new DerivativePipelineAggregator();
result.readFrom(in);
return result;
}
};
public static void registerStreams() {
PipelineAggregatorStreams.registerStream(STREAM, TYPE.stream());
}
private ValueFormatter formatter;
private GapPolicy gapPolicy;
private Double xAxisUnits;
public DerivativePipelineAggregator() {
}
public DerivativePipelineAggregator(String name, String[] bucketsPaths, ValueFormatter formatter, GapPolicy gapPolicy, Long xAxisUnits,
Map<String, Object> metadata) {
super(name, bucketsPaths, metadata);
this.formatter = formatter;
this.gapPolicy = gapPolicy;
this.xAxisUnits = xAxisUnits == null ? null : (double) xAxisUnits;
}
@Override
public Type type() {
return TYPE;
}
@Override
public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext reduceContext) {
InternalHistogram histo = (InternalHistogram) aggregation;
List<? extends InternalHistogram.Bucket> buckets = histo.getBuckets();
InternalHistogram.Factory<? extends InternalHistogram.Bucket> factory = histo.getFactory();
List newBuckets = new ArrayList<>();
Long lastBucketKey = null;
Double lastBucketValue = null;
for (InternalHistogram.Bucket bucket : buckets) {
Long thisBucketKey = resolveBucketKeyAsLong(bucket);
Double thisBucketValue = resolveBucketValue(histo, bucket, bucketsPaths()[0], gapPolicy);
if (lastBucketValue != null && thisBucketValue != null) {
double gradient = thisBucketValue - lastBucketValue;
double xDiff = -1;
if (xAxisUnits != null) {
xDiff = (thisBucketKey - lastBucketKey) / xAxisUnits;
}
List<InternalAggregation> aggs = new ArrayList<>(eagerTransform(bucket.getAggregations().asList(),
AGGREGATION_TRANFORM_FUNCTION));
aggs.add(new InternalDerivative(name(), gradient, xDiff, formatter, new ArrayList<PipelineAggregator>(), metaData()));
InternalHistogram.Bucket newBucket = factory.createBucket(bucket.getKey(), bucket.getDocCount(), new InternalAggregations(
aggs), bucket.getKeyed(), bucket.getFormatter());
newBuckets.add(newBucket);
} else {
newBuckets.add(bucket);
}
lastBucketKey = thisBucketKey;
lastBucketValue = thisBucketValue;
}
return factory.create(newBuckets, histo);
}
private Long resolveBucketKeyAsLong(InternalHistogram.Bucket bucket) {
Object key = bucket.getKey();
if (key instanceof DateTime) {
return ((DateTime) key).getMillis();
} else if (key instanceof Number) {
return ((Number) key).longValue();
} else {
throw new AggregationExecutionException("Bucket keys must be either a Number or a DateTime for aggregation " + name()
+ ". Found bucket with key " + key);
}
}
@Override
public void doReadFrom(StreamInput in) throws IOException {
formatter = ValueFormatterStreams.readOptional(in);
gapPolicy = GapPolicy.readFrom(in);
if (in.readBoolean()) {
xAxisUnits = in.readDouble();
} else {
xAxisUnits = null;
}
}
@Override
public void doWriteTo(StreamOutput out) throws IOException {
ValueFormatterStreams.writeOptional(formatter, out);
gapPolicy.writeTo(out);
boolean hasXAxisUnitsValue = xAxisUnits != null;
out.writeBoolean(hasXAxisUnitsValue);
if (hasXAxisUnitsValue) {
out.writeDouble(xAxisUnits);
}
}
public static class Factory extends PipelineAggregatorFactory {
private final ValueFormatter formatter;
private GapPolicy gapPolicy;
private Long xAxisUnits;
public Factory(String name, String[] bucketsPaths, ValueFormatter formatter, GapPolicy gapPolicy, Long xAxisUnits) {
super(name, TYPE.name(), bucketsPaths);
this.formatter = formatter;
this.gapPolicy = gapPolicy;
this.xAxisUnits = xAxisUnits;
}
@Override
protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
return new DerivativePipelineAggregator(name, bucketsPaths, formatter, gapPolicy, xAxisUnits, metaData);
}
@Override
public void doValidate(AggregatorFactory parent, AggregatorFactory[] aggFactories, List<PipelineAggregatorFactory> pipelineAggregatorFactories) {
if (bucketsPaths.length != 1) {
throw new IllegalStateException(PipelineAggregator.Parser.BUCKETS_PATH.getPreferredName()
+ " must contain a single entry for aggregation [" + name + "]");
}
if (!(parent instanceof HistogramAggregator.Factory)) {
throw new IllegalStateException("derivative aggregation [" + name
+ "] must have a histogram or date_histogram as parent");
} else {
HistogramAggregator.Factory histoParent = (HistogramAggregator.Factory) parent;
if (histoParent.minDocCount() != 0) {
throw new IllegalStateException("parent histogram of derivative aggregation [" + name
+ "] must have min_doc_count of 0");
}
}
}
}
}