- All Implemented Interfaces:
Nested Class Summary
Nested classes/interfaces inherited from class org.elasticsearch.search.aggregations.bucket.BucketsAggregator
BucketsAggregator.BucketBuilderForFixedCount<B>, BucketsAggregator.BucketBuilderForVariable<B>, BucketsAggregator.ResultBuilderForVariable<B>, BucketsAggregator.SingleBucketResultBuilder
Nested classes/interfaces inherited from class org.elasticsearch.search.aggregations.Aggregator
Aggregator.BucketComparator, Aggregator.Parser, Aggregator.SubAggCollectionMode
Fields inherited from class org.elasticsearch.search.aggregations.bucket.BucketsAggregator
Fields inherited from class org.elasticsearch.search.aggregations.AggregatorBase
collectableSubAggregators, DEFAULT_WEIGHT, name, parent, subAggregators
Fields inherited from class org.elasticsearch.search.aggregations.BucketCollector
Method SummaryModifier and TypeMethodDescription
(long owningBucketOrds)Build the results of this aggregation.Build an empty aggregation.
protected voidCan be overridden by aggregator implementation to be called back when the collection phase ends.
(org.apache.lucene.index.LeafReaderContext ctx, LeafBucketCollector sub)Collect results for this leaf.
(org.apache.lucene.index.LeafReaderContext ctx)Can be overridden by aggregator implementations that like the perform an operation before the leaf collectors of children aggregators are instantiated for the next segment.
Methods inherited from class org.elasticsearch.search.aggregations.bucket.BucketsAggregator
bucketComparator, bucketDocCount, buildAggregationsForFixedBucketCount, buildAggregationsForSingleBucket, buildAggregationsForVariableBuckets, buildSubAggsForAllBuckets, buildSubAggsForBuckets, buildSubAggsForBuckets, close, collectBucket, collectExistingBucket, descendsFromGlobalAggregator, getDocCounts, grow, incrementBucketDocCount, maxBucketOrd, prepareSubAggs, resolveSortPath, rewriteBuckets
Methods inherited from class org.elasticsearch.search.aggregations.AggregatorBase
addRequestCircuitBreakerBytes, bigArrays, buildEmptySubAggregations, doClose, doPreCollection, getLeafCollector, metadata, name, parent, pointReaderIfAvailable, postCollection, preCollection, scoreMode, searcher, subAggregator, subAggregators, topLevelQuery, toString
Methods inherited from class org.elasticsearch.search.aggregations.Aggregator
buildTopLevel, collectDebugInfo, resolveSortPathOnValidAgg
getLeafCollectorpublic LeafBucketCollector getLeafCollector
(org.apache.lucene.index.LeafReaderContext ctx, LeafBucketCollector sub) throws IOExceptionCollect results for this leaf.
Most Aggregators will return a custom
LeafBucketCollectorthat collects document information for every hit. Callers of this method will make sure to call
collectfor every hit. So any
Aggregatorthat returns a customer LeafBucketCollector from this method runs at best
O(hits)time. See the
sumAggregator for a fairly strait forward example of this.
Some Aggregators are able to correctly collect results on their own, without being iterated by the top level query or the rest of the aggregations framework. These aggregations collect what they need by calling methods on
LeafReaderContextand then they return
LeafBucketCollector.NO_OP_COLLECTORto signal that they've done their own collection. These aggregations can do better than
O(hits). See the
minAggregator for an example of an aggregation that does this. It happens to run in constant time in some cases.
In other cases
MinAggregatorcan't get correct results by taking the constant time path so instead it returns a custom
LeafBucketCollector. This is fairly common for aggregations that have these fast paths because most of these fast paths are only possible when the aggregation is at the root of the tree.
Its also useful to look at the
filtersAggregator chooses whether or not it can use the fast path before building the Aggregator rather than on each leaf. Either is fine.
- Specified by:
preGetSubLeafCollectorsprotected void preGetSubLeafCollectors
(org.apache.lucene.index.LeafReaderContext ctx) throws IOExceptionCan be overridden by aggregator implementations that like the perform an operation before the leaf collectors of children aggregators are instantiated for the next segment.
doPostCollectionprotected void doPostCollection() throws IOExceptionCan be overridden by aggregator implementation to be called back when the collection phase ends.
buildAggregationspublic InternalAggregation buildAggregations
(long owningBucketOrds) throws IOExceptionDescription copied from class:
AggregatorBuild the results of this aggregation.
- Specified by:
owningBucketOrds- the ordinals of the buckets that we want to collect from this aggregation
- the results for each ordinal, in the same order as the array of ordinals
buildEmptyAggregationpublic InternalAggregation buildEmptyAggregation()Description copied from class:
AggregatorBuild an empty aggregation.
- Specified by: