Class StandardFacetsAccumulator
- java.lang.Object
-
- org.apache.lucene.facet.search.FacetsAccumulator
-
- org.apache.lucene.facet.search.StandardFacetsAccumulator
-
- Direct Known Subclasses:
AdaptiveFacetsAccumulator
,SamplingAccumulator
public class StandardFacetsAccumulator extends FacetsAccumulator
Standard implementation forFacetsAccumulator
, utilizing partitions to save on memory.Why partitions? Because if there are say 100M categories out of which only top K are required, we must first compute value for all 100M categories (going over all documents) and only then could we select top K. This is made easier on memory by working in partitions of distinct categories: Once a values for a partition are found, we take the top K for that partition and work on the next partition, them merge the top K of both, and so forth, thereby computing top K with RAM needs for the size of a single partition rather than for the size of all the 100M categories.
Decision on partitions size is done at indexing time, and the facet information for each partition is maintained separately.
Implementation detail: Since facets information of each partition is maintained in a separate "category list", we can be more efficient at search time, because only the facet info for a single partition need to be read while processing that partition.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
-
-
Field Summary
Fields Modifier and Type Field Description protected FloatArrayAllocator
floatArrayAllocator
protected IntArrayAllocator
intArrayAllocator
protected boolean
isUsingComplements
protected int
maxPartitions
protected int
partitionSize
-
Fields inherited from class org.apache.lucene.facet.search.FacetsAccumulator
DEFAULT_COMPLEMENT_THRESHOLD, DISABLE_COMPLEMENT, FORCE_COMPLEMENT, indexReader, searchParams, taxonomyReader
-
-
Constructor Summary
Constructors Constructor Description StandardFacetsAccumulator(FacetSearchParams searchParams, org.apache.lucene.index.IndexReader indexReader, TaxonomyReader taxonomyReader)
StandardFacetsAccumulator(FacetSearchParams searchParams, org.apache.lucene.index.IndexReader indexReader, TaxonomyReader taxonomyReader, IntArrayAllocator intArrayAllocator, FloatArrayAllocator floatArrayAllocator)
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description List<FacetResult>
accumulate(ScoredDocIDs docids)
Accumulate facets over given documents, according to facet requests in effect.protected ScoredDocIDs
actualDocsToAccumulate(ScoredDocIDs docids)
Set the actual set of documents over which accumulation should take place.protected HashMap<CategoryListIterator,Aggregator>
getCategoryListMap(FacetArrays facetArrays, int partition)
protected double
getTotalCountsFactor()
Expert: factor by which counts should be multiplied when initializing the count arrays from total counts.protected boolean
shouldComplement(ScoredDocIDs docids)
Check if it is worth to use complements-
Methods inherited from class org.apache.lucene.facet.search.FacetsAccumulator
getComplementThreshold, isAllowLabeling, mayComplement, setAllowLabeling, setComplementThreshold
-
-
-
-
Field Detail
-
intArrayAllocator
protected final IntArrayAllocator intArrayAllocator
-
floatArrayAllocator
protected final FloatArrayAllocator floatArrayAllocator
-
partitionSize
protected int partitionSize
-
maxPartitions
protected int maxPartitions
-
isUsingComplements
protected boolean isUsingComplements
-
-
Constructor Detail
-
StandardFacetsAccumulator
public StandardFacetsAccumulator(FacetSearchParams searchParams, org.apache.lucene.index.IndexReader indexReader, TaxonomyReader taxonomyReader, IntArrayAllocator intArrayAllocator, FloatArrayAllocator floatArrayAllocator)
-
StandardFacetsAccumulator
public StandardFacetsAccumulator(FacetSearchParams searchParams, org.apache.lucene.index.IndexReader indexReader, TaxonomyReader taxonomyReader)
-
-
Method Detail
-
accumulate
public List<FacetResult> accumulate(ScoredDocIDs docids) throws IOException
Description copied from class:FacetsAccumulator
Accumulate facets over given documents, according to facet requests in effect.- Specified by:
accumulate
in classFacetsAccumulator
- Parameters:
docids
- documents (and their scores) for which facets are Accumulated.- Returns:
- Accumulated facets.
- Throws:
IOException
- on error.
-
actualDocsToAccumulate
protected ScoredDocIDs actualDocsToAccumulate(ScoredDocIDs docids) throws IOException
Set the actual set of documents over which accumulation should take place.Allows to override the set of documents to accumulate for. Invoked just before actual accumulating starts. From this point that set of documents remains unmodified. Default implementation just returns the input unchanged.
- Parameters:
docids
- candidate documents to accumulate for- Returns:
- actual documents to accumulate for
- Throws:
IOException
-
shouldComplement
protected boolean shouldComplement(ScoredDocIDs docids)
Check if it is worth to use complements
-
getTotalCountsFactor
protected double getTotalCountsFactor()
Expert: factor by which counts should be multiplied when initializing the count arrays from total counts. Default implementation for this returns 1, which is a no op.- Returns:
- a factor by which total counts should be multiplied
-
getCategoryListMap
protected HashMap<CategoryListIterator,Aggregator> getCategoryListMap(FacetArrays facetArrays, int partition) throws IOException
Create anAggregator
and aCategoryListIterator
for each and everyFacetRequest
. Generating a map, matching each categoryListIterator to its matching aggregator.If two CategoryListIterators are served by the same aggregator, a single aggregator is returned for both. NOTE: If a given category list iterator is needed with two different aggregators (e.g counting and association) - an exception is thrown as this functionality is not supported at this time.
- Throws:
IOException
-
-