org.apache.lucene.facet.search.params
Class CountFacetRequest

java.lang.Object
  org.apache.lucene.facet.search.params.FacetRequest
      org.apache.lucene.facet.search.params.CountFacetRequest

All Implemented Interfaces:

Cloneable

public class CountFacetRequest
extends FacetRequest

Facet request for counting facets.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.facet.search.params.FacetRequest

FacetRequest.ResultMode, FacetRequest.SortBy, FacetRequest.SortOrder

Field Summary

Fields inherited from class org.apache.lucene.facet.search.params.FacetRequest

DEFAULT_DEPTH, DEFAULT_RESULT_MODE, DEFAULT_SORT_BY

Constructor Summary

CountFacetRequest(CategoryPath path, int num)
Create a count facet request for a given node in the taxonomy.

Method Summary

Aggregator	createAggregator(boolean useComplements, FacetArrays arrays, IndexReader reader, TaxonomyReader taxonomy) Create an aggregator for this facet request.
double	getValueOf(FacetArrays arrays, int ordinal) Return the value of a category used for facets computations for this request.
boolean	requireDocumentScore() Indicates whether the results of this request depends on each result document's score
boolean	supportsComplements() Indicates whether this facet request is eligible for applying the complements optimization.

Methods inherited from class org.apache.lucene.facet.search.params.FacetRequest

clone, createCategoryListIterator, createFacetResultsHandler, equals, getCategoryPath, getDepth, getNumLabel, getNumResults, getResultMode, getSortBy, getSortOrder, hashCode, setDepth, setNumLabel, setResultMode, setSortBy, setSortOrder, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CountFacetRequest

public CountFacetRequest(CategoryPath path,
                         int num)

Create a count facet request for a given node in the taxonomy.

Parameters:

path - category path of the category of interest.

num - number of child categories for which count info is requeted. reqiested. Default implementation will find top categories, - this behavior can be overridden by overriding FacetRequest.createFacetResultsHandler(TaxonomyReader).

Method Detail

createAggregator

public Aggregator createAggregator(boolean useComplements,
                                   FacetArrays arrays,
                                   IndexReader reader,
                                   TaxonomyReader taxonomy)

Description copied from class: FacetRequest

Create an aggregator for this facet request. Aggregator action depends on request definition. For a count request, it will usually increment the count for that facet.

Specified by:

createAggregator in class FacetRequest

Parameters:

useComplements - whether the complements optimization is being used for current computation.

arrays - provider for facet arrays in use for current computation.

reader - index reader in effect.

taxonomy - reader of taxonomy in effect.

getValueOf

public double getValueOf(FacetArrays arrays,
                         int ordinal)

Description copied from class: FacetRequest

Return the value of a category used for facets computations for this request. For a count request this would be the count for that facet, i.e. an integer number. but for other requests this can be the result of a more complex operation, and the result can be any double precision number. Having this method with a general name value which is double precision allows to have more compact API and code for handling counts and perhaps other requests (such as for associations) very similarly, and by the same code and API, avoiding code duplication.

Specified by:

getValueOf in class FacetRequest

Parameters:

arrays - provider for facet arrays in use for current computation.

ordinal - an index into the count arrays now in effect in arrays. E.g., for ordinal number n, with partition, of size partitionSize, now covering n, getValueOf would be invoked with idx being n % partitionSize.

supportsComplements

public boolean supportsComplements()

Description copied from class: FacetRequest

Indicates whether this facet request is eligible for applying the complements optimization.

Overrides:

supportsComplements in class FacetRequest

requireDocumentScore

public boolean requireDocumentScore()

Description copied from class: FacetRequest

Indicates whether the results of this request depends on each result document's score

Specified by:

requireDocumentScore in class FacetRequest