path: root/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java

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 * 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
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package org.elasticsearch.search.aggregations.bucket.terms;

import org.apache.lucene.search.IndexSearcher;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.AggregationExecutionException;
import org.elasticsearch.search.aggregations.Aggregator;
import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
import org.elasticsearch.search.aggregations.AggregatorFactories;
import org.elasticsearch.search.aggregations.AggregatorFactory;
import org.elasticsearch.search.aggregations.BucketOrder;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.InternalOrder;
import org.elasticsearch.search.aggregations.NonCollectingAggregator;
import org.elasticsearch.search.aggregations.bucket.BucketUtils;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import org.elasticsearch.search.aggregations.support.ValuesSource;
import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
import org.elasticsearch.search.internal.SearchContext;

import java.io.IOException;
import java.util.List;
import java.util.Map;

public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<ValuesSource, TermsAggregatorFactory> {

    private final BucketOrder order;
    private final IncludeExclude includeExclude;
    private final String executionHint;
    private final SubAggCollectionMode collectMode;
    private final TermsAggregator.BucketCountThresholds bucketCountThresholds;
    private boolean showTermDocCountError;

    TermsAggregatorFactory(String name,
                                  ValuesSourceConfig<ValuesSource> config,
                                  BucketOrder order,
                                  IncludeExclude includeExclude,
                                  String executionHint,
                                  SubAggCollectionMode collectMode,
                                  TermsAggregator.BucketCountThresholds bucketCountThresholds,
                                  boolean showTermDocCountError,
                                  SearchContext context,
                                  AggregatorFactory<?> parent,
                                  AggregatorFactories.Builder subFactoriesBuilder,
                                  Map<String, Object> metaData) throws IOException {
        super(name, config, context, parent, subFactoriesBuilder, metaData);
        this.order = order;
        this.includeExclude = includeExclude;
        this.executionHint = executionHint;
        this.collectMode = collectMode;
        this.bucketCountThresholds = bucketCountThresholds;
        this.showTermDocCountError = showTermDocCountError;
    }

    @Override
    protected Aggregator createUnmapped(Aggregator parent, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData)
            throws IOException {
        final InternalAggregation aggregation = new UnmappedTerms(name, order, bucketCountThresholds.getRequiredSize(),
                bucketCountThresholds.getMinDocCount(), pipelineAggregators, metaData);
        return new NonCollectingAggregator(name, context, parent, factories, pipelineAggregators, metaData) {
            {
                // even in the case of an unmapped aggregator, validate the
                // order
                InternalOrder.validate(order, this);
            }

            @Override
            public InternalAggregation buildEmptyAggregation() {
                return aggregation;
            }
        };
    }

    @Override
    protected Aggregator doCreateInternal(ValuesSource valuesSource, Aggregator parent, boolean collectsFromSingleBucket,
            List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
        if (collectsFromSingleBucket == false) {
            return asMultiBucketAggregator(this, context, parent);
        }
        BucketCountThresholds bucketCountThresholds = new BucketCountThresholds(this.bucketCountThresholds);
        if (InternalOrder.isKeyOrder(order) == false
                && bucketCountThresholds.getShardSize() == TermsAggregationBuilder.DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
            // The user has not made a shardSize selection. Use default
            // heuristic to avoid any wrong-ranking caused by distributed
            // counting
            bucketCountThresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize(),
                    context.numberOfShards()));
        }
        bucketCountThresholds.ensureValidity();
        if (valuesSource instanceof ValuesSource.Bytes) {
            ExecutionMode execution = null;
            if (executionHint != null) {
                execution = ExecutionMode.fromString(executionHint);
            }

            // In some cases, using ordinals is just not supported: override it
            if (!(valuesSource instanceof ValuesSource.Bytes.WithOrdinals)) {
                execution = ExecutionMode.MAP;
            }

            final long maxOrd;
            final double ratio;
            if (execution == null || execution.needsGlobalOrdinals()) {
                ValuesSource.Bytes.WithOrdinals valueSourceWithOrdinals = (ValuesSource.Bytes.WithOrdinals) valuesSource;
                IndexSearcher indexSearcher = context.searcher();
                maxOrd = valueSourceWithOrdinals.globalMaxOrd(indexSearcher);
                ratio = maxOrd / ((double) indexSearcher.getIndexReader().numDocs());
            } else {
                maxOrd = -1;
                ratio = -1;
            }

            // Let's try to use a good default
            if (execution == null) {
                // if there is a parent bucket aggregator the number of
                // instances of this aggregator is going
                // to be unbounded and most instances may only aggregate few
                // documents, so use hashed based
                // global ordinals to keep the bucket ords dense.
                // Additionally, if using partitioned terms the regular global
                // ordinals would be sparse so we opt for hash
                if (Aggregator.descendsFromBucketAggregator(parent) ||
                        (includeExclude != null && includeExclude.isPartitionBased())) {
                    execution = ExecutionMode.GLOBAL_ORDINALS_HASH;
                } else {
                    if (factories == AggregatorFactories.EMPTY) {
                        if (ratio <= 0.5 && maxOrd <= 2048) {
                            // 0.5: At least we need reduce the number of global
                            // ordinals look-ups by half
                            // 2048: GLOBAL_ORDINALS_LOW_CARDINALITY has
                            // additional memory usage, which directly linked to
                            // maxOrd, so we need to limit.
                            execution = ExecutionMode.GLOBAL_ORDINALS_LOW_CARDINALITY;
                        } else {
                            execution = ExecutionMode.GLOBAL_ORDINALS;
                        }
                    } else {
                        execution = ExecutionMode.GLOBAL_ORDINALS;
                    }
                }
            }
            SubAggCollectionMode cm = collectMode;
            if (cm == null) {
                cm = SubAggCollectionMode.DEPTH_FIRST;
                if (factories != AggregatorFactories.EMPTY) {
                    cm = subAggCollectionMode(bucketCountThresholds.getShardSize(), maxOrd);
                }
            }

            DocValueFormat format = config.format();
            if ((includeExclude != null) && (includeExclude.isRegexBased()) && format != DocValueFormat.RAW) {
                throw new AggregationExecutionException("Aggregation [" + name + "] cannot support regular expression style include/exclude "
                        + "settings as they can only be applied to string fields. Use an array of values for include/exclude clauses");
            }

            return execution.create(name, factories, valuesSource, order, format, bucketCountThresholds, includeExclude, context, parent,
                    cm, showTermDocCountError, pipelineAggregators, metaData);
        }

        if ((includeExclude != null) && (includeExclude.isRegexBased())) {
            throw new AggregationExecutionException("Aggregation [" + name + "] cannot support regular expression style include/exclude "
                    + "settings as they can only be applied to string fields. Use an array of numeric values for include/exclude clauses used to filter numeric fields");
        }

        if (valuesSource instanceof ValuesSource.Numeric) {
            IncludeExclude.LongFilter longFilter = null;
            SubAggCollectionMode cm = collectMode;
            if (cm == null) {
                if (factories != AggregatorFactories.EMPTY) {
                    cm = subAggCollectionMode(bucketCountThresholds.getShardSize(), -1);
                } else {
                    cm = SubAggCollectionMode.DEPTH_FIRST;
                }
            }
            if (((ValuesSource.Numeric) valuesSource).isFloatingPoint()) {
                if (includeExclude != null) {
                    longFilter = includeExclude.convertToDoubleFilter();
                }
                return new DoubleTermsAggregator(name, factories, (ValuesSource.Numeric) valuesSource, config.format(), order,
                        bucketCountThresholds, context, parent, cm, showTermDocCountError, longFilter,
                        pipelineAggregators, metaData);
            }
            if (includeExclude != null) {
                longFilter = includeExclude.convertToLongFilter(config.format());
            }
            return new LongTermsAggregator(name, factories, (ValuesSource.Numeric) valuesSource, config.format(), order,
                    bucketCountThresholds, context, parent, cm, showTermDocCountError, longFilter, pipelineAggregators,
                    metaData);
        }

        throw new AggregationExecutionException("terms aggregation cannot be applied to field [" + config.fieldContext().field()
                + "]. It can only be applied to numeric or string fields.");
    }

    // return the SubAggCollectionMode that this aggregation should use based on the expected size
    // and the cardinality of the field
    static SubAggCollectionMode subAggCollectionMode(int expectedSize, long maxOrd) {
        if (expectedSize == Integer.MAX_VALUE) {
            // return all buckets
            return SubAggCollectionMode.DEPTH_FIRST;
        }
        if (maxOrd == -1 || maxOrd > expectedSize) {
            // use breadth_first if the cardinality is bigger than the expected size or unknown (-1)
            return SubAggCollectionMode.BREADTH_FIRST;
        }
        return SubAggCollectionMode.DEPTH_FIRST;
    }

    public enum ExecutionMode {

        MAP(new ParseField("map")) {

            @Override
            Aggregator create(String name,
                              AggregatorFactories factories,
                              ValuesSource valuesSource,
                              BucketOrder order,
                              DocValueFormat format,
                              TermsAggregator.BucketCountThresholds bucketCountThresholds,
                              IncludeExclude includeExclude,
                              SearchContext context,
                              Aggregator parent,
                              SubAggCollectionMode subAggCollectMode,
                              boolean showTermDocCountError,
                              List<PipelineAggregator> pipelineAggregators,
                              Map<String, Object> metaData) throws IOException {

                final IncludeExclude.StringFilter filter = includeExclude == null ? null : includeExclude.convertToStringFilter(format);
                return new StringTermsAggregator(name, factories, valuesSource, order, format, bucketCountThresholds, filter,
                        context, parent, subAggCollectMode, showTermDocCountError, pipelineAggregators, metaData);

            }

            @Override
            boolean needsGlobalOrdinals() {
                return false;
            }

        },
        GLOBAL_ORDINALS(new ParseField("global_ordinals")) {

            @Override
            Aggregator create(String name,
                              AggregatorFactories factories,
                              ValuesSource valuesSource,
                              BucketOrder order,
                              DocValueFormat format,
                              TermsAggregator.BucketCountThresholds bucketCountThresholds,
                              IncludeExclude includeExclude,
                              SearchContext context, Aggregator parent,
                              SubAggCollectionMode subAggCollectMode,
                              boolean showTermDocCountError,
                              List<PipelineAggregator> pipelineAggregators,
                              Map<String, Object> metaData) throws IOException {

                final IncludeExclude.OrdinalsFilter filter = includeExclude == null ? null : includeExclude.convertToOrdinalsFilter(format);
                return new GlobalOrdinalsStringTermsAggregator(name, factories, (ValuesSource.Bytes.WithOrdinals) valuesSource, order,
                        format, bucketCountThresholds, filter, context, parent, false, subAggCollectMode, showTermDocCountError,
                        pipelineAggregators, metaData);

            }

            @Override
            boolean needsGlobalOrdinals() {
                return true;
            }

        },
        GLOBAL_ORDINALS_HASH(new ParseField("global_ordinals_hash")) {

            @Override
            Aggregator create(String name,
                              AggregatorFactories factories,
                              ValuesSource valuesSource,
                              BucketOrder order,
                              DocValueFormat format,
                              TermsAggregator.BucketCountThresholds bucketCountThresholds,
                              IncludeExclude includeExclude,
                              SearchContext context,
                              Aggregator parent,
                              SubAggCollectionMode subAggCollectMode,
                              boolean showTermDocCountError,
                              List<PipelineAggregator> pipelineAggregators,
                              Map<String, Object> metaData) throws IOException {

                final IncludeExclude.OrdinalsFilter filter = includeExclude == null ? null : includeExclude.convertToOrdinalsFilter(format);
                return new GlobalOrdinalsStringTermsAggregator(name, factories, (ValuesSource.Bytes.WithOrdinals) valuesSource,
                    order, format, bucketCountThresholds, filter, context, parent, true, subAggCollectMode,
                    showTermDocCountError, pipelineAggregators, metaData);

            }

            @Override
            boolean needsGlobalOrdinals() {
                return true;
            }
        },
        GLOBAL_ORDINALS_LOW_CARDINALITY(new ParseField("global_ordinals_low_cardinality")) {

            @Override
            Aggregator create(String name,
                              AggregatorFactories factories,
                              ValuesSource valuesSource,
                              BucketOrder order,
                              DocValueFormat format,
                              TermsAggregator.BucketCountThresholds bucketCountThresholds,
                              IncludeExclude includeExclude,
                              SearchContext context,
                              Aggregator parent,
                              SubAggCollectionMode subAggCollectMode,
                              boolean showTermDocCountError,
                              List<PipelineAggregator> pipelineAggregators,
                              Map<String, Object> metaData) throws IOException {

                if (includeExclude != null || factories.countAggregators() > 0
                        // we need the FieldData impl to be able to extract the
                        // segment to global ord mapping
                        || valuesSource.getClass() != ValuesSource.Bytes.FieldData.class) {
                    return GLOBAL_ORDINALS.create(name, factories, valuesSource, order, format, bucketCountThresholds, includeExclude,
                            context, parent, subAggCollectMode, showTermDocCountError, pipelineAggregators, metaData);
                }
                return new GlobalOrdinalsStringTermsAggregator.LowCardinality(name, factories,
                        (ValuesSource.Bytes.WithOrdinals) valuesSource, order, format, bucketCountThresholds, context, parent,
                        false, subAggCollectMode, showTermDocCountError, pipelineAggregators, metaData);

            }

            @Override
            boolean needsGlobalOrdinals() {
                return true;
            }
        };

        public static ExecutionMode fromString(String value) {
            for (ExecutionMode mode : values()) {
                if (mode.parseField.match(value)) {
                    return mode;
                }
            }
            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + values());
        }

        private final ParseField parseField;

        ExecutionMode(ParseField parseField) {
            this.parseField = parseField;
        }

        abstract Aggregator create(String name,
                                   AggregatorFactories factories,
                                   ValuesSource valuesSource,
                                   BucketOrder order,
                                   DocValueFormat format,
                                   TermsAggregator.BucketCountThresholds bucketCountThresholds,
                                   IncludeExclude includeExclude,
                                   SearchContext context,
                                   Aggregator parent,
                                   SubAggCollectionMode subAggCollectMode,
                                   boolean showTermDocCountError,
                                   List<PipelineAggregator> pipelineAggregators,
                                   Map<String, Object> metaData) throws IOException;

        abstract boolean needsGlobalOrdinals();

        @Override
        public String toString() {
            return parseField.getPreferredName();
        }
    }

}