org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogram Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :core
/*
* 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.histogram;
import org.apache.lucene.util.CollectionUtil;
import org.apache.lucene.util.PriorityQueue;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.InternalAggregations;
import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
import org.elasticsearch.search.aggregations.bucket.MultiBucketsAggregation;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
/**
* Imelementation of {@link Histogram}.
*/
public final class InternalHistogram extends InternalMultiBucketAggregation
implements Histogram, HistogramFactory {
static final Type TYPE = new Type("histogram");
public static class Bucket extends InternalMultiBucketAggregation.InternalBucket implements Histogram.Bucket {
final double key;
final long docCount;
final InternalAggregations aggregations;
private final transient boolean keyed;
protected final transient DocValueFormat format;
public Bucket(double key, long docCount, boolean keyed, DocValueFormat format,
InternalAggregations aggregations) {
this.format = format;
this.keyed = keyed;
this.key = key;
this.docCount = docCount;
this.aggregations = aggregations;
}
/**
* Read from a stream.
*/
public Bucket(StreamInput in, boolean keyed, DocValueFormat format) throws IOException {
this.format = format;
this.keyed = keyed;
key = in.readDouble();
docCount = in.readVLong();
aggregations = InternalAggregations.readAggregations(in);
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeDouble(key);
out.writeVLong(docCount);
aggregations.writeTo(out);
}
@Override
public String getKeyAsString() {
return format.format(key);
}
@Override
public Object getKey() {
return key;
}
@Override
public long getDocCount() {
return docCount;
}
@Override
public Aggregations getAggregations() {
return aggregations;
}
Bucket reduce(List buckets, ReduceContext context) {
List aggregations = new ArrayList<>(buckets.size());
long docCount = 0;
for (Bucket bucket : buckets) {
docCount += bucket.docCount;
aggregations.add((InternalAggregations) bucket.getAggregations());
}
InternalAggregations aggs = InternalAggregations.reduce(aggregations, context);
return new InternalHistogram.Bucket(key, docCount, keyed, format, aggs);
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
String keyAsString = format.format(key);
if (keyed) {
builder.startObject(keyAsString);
} else {
builder.startObject();
}
if (format != DocValueFormat.RAW) {
builder.field(CommonFields.KEY_AS_STRING, keyAsString);
}
builder.field(CommonFields.KEY, key);
builder.field(CommonFields.DOC_COUNT, docCount);
aggregations.toXContentInternal(builder, params);
builder.endObject();
return builder;
}
public DocValueFormat getFormatter() {
return format;
}
public boolean getKeyed() {
return keyed;
}
}
static class EmptyBucketInfo {
final double interval, offset, minBound, maxBound;
final InternalAggregations subAggregations;
EmptyBucketInfo(double interval, double offset, double minBound, double maxBound, InternalAggregations subAggregations) {
this.interval = interval;
this.offset = offset;
this.minBound = minBound;
this.maxBound = maxBound;
this.subAggregations = subAggregations;
}
EmptyBucketInfo(StreamInput in) throws IOException {
this(in.readDouble(), in.readDouble(), in.readDouble(), in.readDouble(), InternalAggregations.readAggregations(in));
}
public void writeTo(StreamOutput out) throws IOException {
out.writeDouble(interval);
out.writeDouble(offset);
out.writeDouble(minBound);
out.writeDouble(maxBound);
subAggregations.writeTo(out);
}
}
private final List buckets;
private final InternalOrder order;
private final DocValueFormat format;
private final boolean keyed;
private final long minDocCount;
private final EmptyBucketInfo emptyBucketInfo;
InternalHistogram(String name, List buckets, InternalOrder order, long minDocCount, EmptyBucketInfo emptyBucketInfo,
DocValueFormat formatter, boolean keyed, List pipelineAggregators,
Map metaData) {
super(name, pipelineAggregators, metaData);
this.buckets = buckets;
this.order = order;
assert (minDocCount == 0) == (emptyBucketInfo != null);
this.minDocCount = minDocCount;
this.emptyBucketInfo = emptyBucketInfo;
this.format = formatter;
this.keyed = keyed;
}
/**
* Stream from a stream.
*/
public InternalHistogram(StreamInput in) throws IOException {
super(in);
order = InternalOrder.Streams.readOrder(in);
minDocCount = in.readVLong();
if (minDocCount == 0) {
emptyBucketInfo = new EmptyBucketInfo(in);
} else {
emptyBucketInfo = null;
}
format = in.readNamedWriteable(DocValueFormat.class);
keyed = in.readBoolean();
buckets = in.readList(stream -> new Bucket(stream, keyed, format));
}
@Override
protected void doWriteTo(StreamOutput out) throws IOException {
InternalOrder.Streams.writeOrder(order, out);
out.writeVLong(minDocCount);
if (minDocCount == 0) {
emptyBucketInfo.writeTo(out);
}
out.writeNamedWriteable(format);
out.writeBoolean(keyed);
out.writeList(buckets);
}
@Override
public String getWriteableName() {
return HistogramAggregationBuilder.NAME;
}
@Override
public List getBuckets() {
return Collections.unmodifiableList(buckets);
}
@Override
public InternalHistogram create(List buckets) {
return new InternalHistogram(name, buckets, order, minDocCount, emptyBucketInfo, format, keyed, pipelineAggregators(), metaData);
}
@Override
public Bucket createBucket(InternalAggregations aggregations, Bucket prototype) {
return new Bucket(prototype.key, prototype.docCount, prototype.keyed, prototype.format, aggregations);
}
private static class IteratorAndCurrent {
private final Iterator iterator;
private Bucket current;
IteratorAndCurrent(Iterator iterator) {
this.iterator = iterator;
current = iterator.next();
}
}
private List reduceBuckets(List aggregations, ReduceContext reduceContext) {
final PriorityQueue pq = new PriorityQueue(aggregations.size()) {
@Override
protected boolean lessThan(IteratorAndCurrent a, IteratorAndCurrent b) {
return a.current.key < b.current.key;
}
};
for (InternalAggregation aggregation : aggregations) {
InternalHistogram histogram = (InternalHistogram) aggregation;
if (histogram.buckets.isEmpty() == false) {
pq.add(new IteratorAndCurrent(histogram.buckets.iterator()));
}
}
List reducedBuckets = new ArrayList<>();
if (pq.size() > 0) {
// list of buckets coming from different shards that have the same key
List currentBuckets = new ArrayList<>();
double key = pq.top().current.key;
do {
final IteratorAndCurrent top = pq.top();
if (top.current.key != key) {
// the key changes, reduce what we already buffered and reset the buffer for current buckets
final Bucket reduced = currentBuckets.get(0).reduce(currentBuckets, reduceContext);
if (reduced.getDocCount() >= minDocCount) {
reducedBuckets.add(reduced);
}
currentBuckets.clear();
key = top.current.key;
}
currentBuckets.add(top.current);
if (top.iterator.hasNext()) {
final Bucket next = top.iterator.next();
assert next.key > top.current.key : "shards must return data sorted by key";
top.current = next;
pq.updateTop();
} else {
pq.pop();
}
} while (pq.size() > 0);
if (currentBuckets.isEmpty() == false) {
final Bucket reduced = currentBuckets.get(0).reduce(currentBuckets, reduceContext);
if (reduced.getDocCount() >= minDocCount) {
reducedBuckets.add(reduced);
}
}
}
return reducedBuckets;
}
private double nextKey(double key) {
return round(key + emptyBucketInfo.interval + emptyBucketInfo.interval / 2);
}
private double round(double key) {
return Math.floor((key - emptyBucketInfo.offset) / emptyBucketInfo.interval) * emptyBucketInfo.interval + emptyBucketInfo.offset;
}
private void addEmptyBuckets(List list, ReduceContext reduceContext) {
ListIterator iter = list.listIterator();
// first adding all the empty buckets *before* the actual data (based on th extended_bounds.min the user requested)
InternalAggregations reducedEmptySubAggs = InternalAggregations.reduce(
Collections.singletonList(emptyBucketInfo.subAggregations),
reduceContext);
if (iter.hasNext() == false) {
// fill with empty buckets
for (double key = round(emptyBucketInfo.minBound); key <= emptyBucketInfo.maxBound; key = nextKey(key)) {
iter.add(new Bucket(key, 0, keyed, format, reducedEmptySubAggs));
}
} else {
Bucket first = list.get(iter.nextIndex());
if (Double.isFinite(emptyBucketInfo.minBound)) {
// fill with empty buckets until the first key
for (double key = round(emptyBucketInfo.minBound); key < first.key; key = nextKey(key)) {
iter.add(new Bucket(key, 0, keyed, format, reducedEmptySubAggs));
}
}
// now adding the empty buckets within the actual data,
// e.g. if the data series is [1,2,3,7] there're 3 empty buckets that will be created for 4,5,6
Bucket lastBucket = null;
do {
Bucket nextBucket = list.get(iter.nextIndex());
if (lastBucket != null) {
double key = nextKey(lastBucket.key);
while (key < nextBucket.key) {
iter.add(new Bucket(key, 0, keyed, format, reducedEmptySubAggs));
key = nextKey(key);
}
assert key == nextBucket.key;
}
lastBucket = iter.next();
} while (iter.hasNext());
// finally, adding the empty buckets *after* the actual data (based on the extended_bounds.max requested by the user)
for (double key = nextKey(lastBucket.key); key <= emptyBucketInfo.maxBound; key = nextKey(key)) {
iter.add(new Bucket(key, 0, keyed, format, reducedEmptySubAggs));
}
}
}
@Override
public InternalAggregation doReduce(List aggregations, ReduceContext reduceContext) {
List reducedBuckets = reduceBuckets(aggregations, reduceContext);
// adding empty buckets if needed
if (minDocCount == 0) {
addEmptyBuckets(reducedBuckets, reduceContext);
}
if (order == InternalOrder.KEY_ASC) {
// nothing to do, data are already sorted since shards return
// sorted buckets and the merge-sort performed by reduceBuckets
// maintains order
} else if (order == InternalOrder.KEY_DESC) {
// we just need to reverse here...
List reverse = new ArrayList<>(reducedBuckets);
Collections.reverse(reverse);
reducedBuckets = reverse;
} else {
// sorted by sub-aggregation, need to fall back to a costly n*log(n) sort
CollectionUtil.introSort(reducedBuckets, order.comparator());
}
return new InternalHistogram(getName(), reducedBuckets, order, minDocCount, emptyBucketInfo, format, keyed, pipelineAggregators(),
getMetaData());
}
@Override
public XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
if (keyed) {
builder.startObject(CommonFields.BUCKETS);
} else {
builder.startArray(CommonFields.BUCKETS);
}
for (Bucket bucket : buckets) {
bucket.toXContent(builder, params);
}
if (keyed) {
builder.endObject();
} else {
builder.endArray();
}
return builder;
}
// HistogramFactory method impls
@Override
public Number getKey(MultiBucketsAggregation.Bucket bucket) {
return ((Bucket) bucket).key;
}
@Override
public Number nextKey(Number key) {
return nextKey(key.doubleValue());
}
@Override
public InternalAggregation createAggregation(List buckets) {
// convert buckets to the right type
List buckets2 = new ArrayList<>(buckets.size());
for (Object b : buckets) {
buckets2.add((Bucket) b);
}
buckets2 = Collections.unmodifiableList(buckets2);
return new InternalHistogram(name, buckets2, order, minDocCount, emptyBucketInfo, format,
keyed, pipelineAggregators(), getMetaData());
}
@Override
public Bucket createBucket(Number key, long docCount, InternalAggregations aggregations) {
return new Bucket(key.doubleValue(), docCount, keyed, format, aggregations);
}
}