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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.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.rounding.Rounding;
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 org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
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 InternalDateHistogram extends InternalMultiBucketAggregation
implements Histogram, HistogramFactory {
static final Type TYPE = new Type("date_histogram");
public static class Bucket extends InternalMultiBucketAggregation.InternalBucket implements Histogram.Bucket {
final long key;
final long docCount;
final InternalAggregations aggregations;
private final transient boolean keyed;
protected final transient DocValueFormat format;
public Bucket(long 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.readLong();
docCount = in.readVLong();
aggregations = InternalAggregations.readAggregations(in);
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeLong(key);
out.writeVLong(docCount);
aggregations.writeTo(out);
}
@Override
public String getKeyAsString() {
return format.format(key);
}
@Override
public Object getKey() {
return new DateTime(key, DateTimeZone.UTC);
}
@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 InternalDateHistogram.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 Rounding rounding;
final InternalAggregations subAggregations;
final ExtendedBounds bounds;
EmptyBucketInfo(Rounding rounding, InternalAggregations subAggregations) {
this(rounding, subAggregations, null);
}
EmptyBucketInfo(Rounding rounding, InternalAggregations subAggregations, ExtendedBounds bounds) {
this.rounding = rounding;
this.subAggregations = subAggregations;
this.bounds = bounds;
}
EmptyBucketInfo(StreamInput in) throws IOException {
rounding = Rounding.Streams.read(in);
subAggregations = InternalAggregations.readAggregations(in);
bounds = in.readOptionalWriteable(ExtendedBounds::new);
}
void writeTo(StreamOutput out) throws IOException {
Rounding.Streams.write(rounding, out);
subAggregations.writeTo(out);
out.writeOptionalWriteable(bounds);
}
}
private final List buckets;
private final InternalOrder order;
private final DocValueFormat format;
private final boolean keyed;
private final long minDocCount;
private final long offset;
private final EmptyBucketInfo emptyBucketInfo;
InternalDateHistogram(String name, List buckets, InternalOrder order, long minDocCount, long offset,
EmptyBucketInfo emptyBucketInfo,
DocValueFormat formatter, boolean keyed, List pipelineAggregators,
Map metaData) {
super(name, pipelineAggregators, metaData);
this.buckets = buckets;
this.order = order;
this.offset = offset;
assert (minDocCount == 0) == (emptyBucketInfo != null);
this.minDocCount = minDocCount;
this.emptyBucketInfo = emptyBucketInfo;
this.format = formatter;
this.keyed = keyed;
}
/**
* Stream from a stream.
*/
public InternalDateHistogram(StreamInput in) throws IOException {
super(in);
order = InternalOrder.Streams.readOrder(in);
minDocCount = in.readVLong();
if (minDocCount == 0) {
emptyBucketInfo = new EmptyBucketInfo(in);
} else {
emptyBucketInfo = null;
}
offset = in.readLong();
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.writeLong(offset);
out.writeNamedWriteable(format);
out.writeBoolean(keyed);
out.writeList(buckets);
}
@Override
public String getWriteableName() {
return DateHistogramAggregationBuilder.NAME;
}
@Override
public List getBuckets() {
return Collections.unmodifiableList(buckets);
}
@Override
public InternalDateHistogram create(List buckets) {
return new InternalDateHistogram(name, buckets, order, minDocCount, offset, 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) {
InternalDateHistogram histogram = (InternalDateHistogram) 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 void addEmptyBuckets(List list, ReduceContext reduceContext) {
Bucket lastBucket = null;
ExtendedBounds bounds = emptyBucketInfo.bounds;
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 (bounds != null) {
Bucket firstBucket = iter.hasNext() ? list.get(iter.nextIndex()) : null;
if (firstBucket == null) {
if (bounds.getMin() != null && bounds.getMax() != null) {
long key = bounds.getMin();
long max = bounds.getMax();
while (key <= max) {
iter.add(new InternalDateHistogram.Bucket(key, 0, keyed, format, reducedEmptySubAggs));
key = nextKey(key).longValue();
}
}
} else {
if (bounds.getMin() != null) {
long key = bounds.getMin();
if (key < firstBucket.key) {
while (key < firstBucket.key) {
iter.add(new InternalDateHistogram.Bucket(key, 0, keyed, format, reducedEmptySubAggs));
key = nextKey(key).longValue();
}
}
}
}
}
// 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
while (iter.hasNext()) {
Bucket nextBucket = list.get(iter.nextIndex());
if (lastBucket != null) {
long key = nextKey(lastBucket.key).longValue();
while (key < nextBucket.key) {
iter.add(new InternalDateHistogram.Bucket(key, 0, keyed, format, reducedEmptySubAggs));
key = nextKey(key).longValue();
}
assert key == nextBucket.key;
}
lastBucket = iter.next();
}
// finally, adding the empty buckets *after* the actual data (based on the extended_bounds.max requested by the user)
if (bounds != null && lastBucket != null && bounds.getMax() != null && bounds.getMax() > lastBucket.key) {
long key = emptyBucketInfo.rounding.nextRoundingValue(lastBucket.key);
long max = bounds.getMax();
while (key <= max) {
iter.add(new InternalDateHistogram.Bucket(key, 0, keyed, format, reducedEmptySubAggs));
key = emptyBucketInfo.rounding.nextRoundingValue(key);
}
}
}
@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 InternalDateHistogram(getName(), reducedBuckets, order, minDocCount, offset, 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 emptyBucketInfo.rounding.nextRoundingValue(key.longValue() - offset) + offset;
}
@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 InternalDateHistogram(name, buckets2, order, minDocCount, offset, emptyBucketInfo, format,
keyed, pipelineAggregators(), getMetaData());
}
@Override
public Bucket createBucket(Number key, long docCount, InternalAggregations aggregations) {
return new Bucket(key.longValue(), docCount, keyed, format, aggregations);
}
}