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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;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.Scorer;
import org.elasticsearch.common.lease.Releasables;
import org.elasticsearch.common.util.BigArrays;
import org.elasticsearch.common.util.ObjectArray;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import org.elasticsearch.search.aggregations.support.AggregationContext;
import org.elasticsearch.search.internal.SearchContext.Lifetime;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/**
* A factory that knows how to create an {@link Aggregator} of a specific type.
*/
public abstract class AggregatorFactory {
protected String name;
protected String type;
protected AggregatorFactory parent;
protected AggregatorFactories factories = AggregatorFactories.EMPTY;
protected Map metaData;
/**
* Constructs a new aggregator factory.
*
* @param name The aggregation name
* @param type The aggregation type
*/
public AggregatorFactory(String name, String type) {
this.name = name;
this.type = type;
}
/**
* Registers sub-factories with this factory. The sub-factory will be responsible for the creation of sub-aggregators under the
* aggregator created by this factory.
*
* @param subFactories The sub-factories
* @return this factory (fluent interface)
*/
public AggregatorFactory subFactories(AggregatorFactories subFactories) {
this.factories = subFactories;
this.factories.setParent(this);
return this;
}
public String name() {
return name;
}
/**
* Validates the state of this factory (makes sure the factory is properly configured)
*/
public final void validate() {
doValidate();
factories.validate();
}
/**
* @return The parent factory if one exists (will always return {@code null} for top level aggregator factories).
*/
public AggregatorFactory parent() {
return parent;
}
protected abstract Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
List pipelineAggregators, Map metaData) throws IOException;
/**
* Creates the aggregator
*
* @param context The aggregation context
* @param parent The parent aggregator (if this is a top level factory, the parent will be {@code null})
* @param collectsFromSingleBucket If true then the created aggregator will only be collected with 0 as a bucket ordinal.
* Some factories can take advantage of this in order to return more optimized implementations.
*
* @return The created aggregator
*/
public final Aggregator create(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket) throws IOException {
return createInternal(context, parent, collectsFromSingleBucket, this.factories.createPipelineAggregators(), this.metaData);
}
public void doValidate() {
}
public void setMetaData(Map metaData) {
this.metaData = metaData;
}
/**
* Utility method. Given an {@link AggregatorFactory} that creates {@link Aggregator}s that only know how
* to collect bucket 0, this returns an aggregator that can collect any bucket.
*/
protected static Aggregator asMultiBucketAggregator(final AggregatorFactory factory, final AggregationContext context, final Aggregator parent) throws IOException {
final Aggregator first = factory.create(context, parent, true);
final BigArrays bigArrays = context.bigArrays();
return new Aggregator() {
ObjectArray aggregators;
ObjectArray collectors;
{
context.searchContext().addReleasable(this, Lifetime.PHASE);
aggregators = bigArrays.newObjectArray(1);
aggregators.set(0, first);
collectors = bigArrays.newObjectArray(1);
}
@Override
public String name() {
return first.name();
}
@Override
public AggregationContext context() {
return first.context();
}
@Override
public Aggregator parent() {
return first.parent();
}
@Override
public boolean needsScores() {
return first.needsScores();
}
@Override
public Aggregator subAggregator(String name) {
throw new UnsupportedOperationException();
}
@Override
public void preCollection() throws IOException {
for (long i = 0; i < aggregators.size(); ++i) {
final Aggregator aggregator = aggregators.get(i);
if (aggregator != null) {
aggregator.preCollection();
}
}
}
@Override
public void postCollection() throws IOException {
for (long i = 0; i < aggregators.size(); ++i) {
final Aggregator aggregator = aggregators.get(i);
if (aggregator != null) {
aggregator.postCollection();
}
}
}
@Override
public LeafBucketCollector getLeafCollector(final LeafReaderContext ctx) {
for (long i = 0; i < collectors.size(); ++i) {
collectors.set(i, null);
}
return new LeafBucketCollector() {
Scorer scorer;
@Override
public void setScorer(Scorer scorer) throws IOException {
this.scorer = scorer;
}
@Override
public void collect(int doc, long bucket) throws IOException {
aggregators = bigArrays.grow(aggregators, bucket + 1);
collectors = bigArrays.grow(collectors, bucket + 1);
LeafBucketCollector collector = collectors.get(bucket);
if (collector == null) {
Aggregator aggregator = aggregators.get(bucket);
if (aggregator == null) {
aggregator = factory.create(context, parent, true);
aggregator.preCollection();
aggregators.set(bucket, aggregator);
}
collector = aggregator.getLeafCollector(ctx);
collector.setScorer(scorer);
collectors.set(bucket, collector);
}
collector.collect(doc, 0);
}
};
}
@Override
public InternalAggregation buildAggregation(long bucket) throws IOException {
if (bucket < aggregators.size()) {
Aggregator aggregator = aggregators.get(bucket);
if (aggregator != null) {
return aggregator.buildAggregation(0);
}
}
return buildEmptyAggregation();
}
@Override
public InternalAggregation buildEmptyAggregation() {
return first.buildEmptyAggregation();
}
@Override
public void close() {
Releasables.close(aggregators, collectors);
}
};
}
}