# Uses of Package
org.apache.lucene.facet.taxonomy

Packages that use org.apache.lucene.facet.taxonomy
org.apache.lucene.facet: Faceted search.
org.apache.lucene.facet.taxonomy: Taxonomy of Categories.
org.apache.lucene.facet.taxonomy.directory: Taxonomy index implementation using on top of a Directory.
org.apache.lucene.facet.taxonomy.writercache: Improves indexing time by caching a map of CategoryPath to their Ordinal.

Classes in org.apache.lucene.facet.taxonomy used by org.apache.lucene.facet
Class and Description
TaxonomyReader TaxonomyReader is the read-only interface with which the faceted-search library uses the taxonomy during search time.
TaxonomyWriter TaxonomyWriter is the interface which the faceted-search library uses to dynamically build the taxonomy at indexing time.

Classes in org.apache.lucene.facet.taxonomy used by org.apache.lucene.facet.taxonomy
Class and Description
AssociationFacetField Add an instance of this to your `Document` to add a facet label associated with an arbitrary byte[].
FacetLabel Holds a sequence of string components, specifying the hierarchical name of a category.
FloatTaxonomyFacets Base class for all taxonomy-based facets that aggregate to a per-ords float[].
IntTaxonomyFacets Base class for all taxonomy-based facets that aggregate to a per-ords int[].
LRUHashMap LRUHashMap is an extension of Java's HashMap, which has a bounded size(); When it reaches that size, each time a new element is added, the least recently used (LRU) entry is removed.
OrdinalsReader Provides per-document ordinals.
OrdinalsReader.OrdinalsSegmentReader Returns ordinals for documents in one segment.

ParallelTaxonomyArrays
Returns 3 arrays for traversing the taxonomy: `parents`: `parents[i]` denotes the parent of category ordinal `i`. `children`: `children[i]` denotes a child of category ordinal `i`. `siblings`: `siblings[i]` denotes the sibling of category ordinal `i`. To traverse the taxonomy tree, you typically start with `children[0]` (ordinal 0 is reserved for ROOT), and then depends if you want to do DFS or BFS, you call `children[children[0]]` or `siblings[children[0]]` and so forth, respectively.

SearcherTaxonomyManager.SearcherAndTaxonomy Holds a matched pair of `IndexSearcher` and `TaxonomyReader`
TaxonomyFacets Base class for all taxonomy-based facets impls.
TaxonomyReader TaxonomyReader is the read-only interface with which the faceted-search library uses the taxonomy during search time.
TaxonomyReader.ChildrenIterator An iterator over a category's children.

Classes in org.apache.lucene.facet.taxonomy used by org.apache.lucene.facet.taxonomy.directory
Class and Description
FacetLabel Holds a sequence of string components, specifying the hierarchical name of a category.

ParallelTaxonomyArrays
Returns 3 arrays for traversing the taxonomy: `parents`: `parents[i]` denotes the parent of category ordinal `i`. `children`: `children[i]` denotes a child of category ordinal `i`. `siblings`: `siblings[i]` denotes the sibling of category ordinal `i`. To traverse the taxonomy tree, you typically start with `children[0]` (ordinal 0 is reserved for ROOT), and then depends if you want to do DFS or BFS, you call `children[children[0]]` or `siblings[children[0]]` and so forth, respectively.

TaxonomyReader TaxonomyReader is the read-only interface with which the faceted-search library uses the taxonomy during search time.
TaxonomyWriter TaxonomyWriter is the interface which the faceted-search library uses to dynamically build the taxonomy at indexing time.

Classes in org.apache.lucene.facet.taxonomy used by org.apache.lucene.facet.taxonomy.writercache
Class and Description
FacetLabel Holds a sequence of string components, specifying the hierarchical name of a category.