OrdinalMappingLeafReader (Lucene 10.5.0 facet API)
Description: declaration: package: org.apache.lucene.facet.taxonomy, class: OrdinalMappingLeafReader

Package org.apache.lucene.facet.taxonomy

# Class OrdinalMappingLeafReader

java.lang.Object
org.apache.lucene.index.IndexReader
org.apache.lucene.index.LeafReader
org.apache.lucene.index.FilterLeafReader
org.apache.lucene.facet.taxonomy.OrdinalMappingLeafReader

All Implemented Interfaces:
  `Closeable`, `AutoCloseable`

public class OrdinalMappingLeafReader extends FilterLeafReader
A `FilterLeafReader` for updating facets ordinal references, based on an ordinal map. You should use this code in conjunction with merging taxonomies - after you merge taxonomies, you receive an `DirectoryTaxonomyWriter.OrdinalMap` which maps the 'old' ordinals to the 'new' ones. You can use that map to re-map the doc values which contain the facets information (ordinals) either before or while merging the indexes.

For re-mapping the ordinals during index merge, do the following:

     // merge the old taxonomy with the new one.
     OrdinalMap map = new MemoryOrdinalMap();
     DirectoryTaxonomyWriter.addTaxonomy(srcTaxoDir, map);
     int[] ordmap = map.getMap();

     // Add the index and re-map ordinals on the go
     DirectoryReader reader = DirectoryReader.open(oldDir);
     IndexWriterConfig conf = new IndexWriterConfig(VER, ANALYZER);
     IndexWriter writer = new IndexWriter(newDir, conf);
     List<LeafReaderContext> leaves = reader.leaves();
     LeafReader wrappedLeaves[] = new LeafReader[leaves.size()];
     for (int i = 0; i < leaves.size(); i++) {
       wrappedLeaves[i] = new OrdinalMappingLeafReader(leaves.get(i).reader(), ordmap);
     }
     writer.addIndexes(new MultiReader(wrappedLeaves));
     writer.commit();

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.index.FilterLeafReader

  `FilterLeafReader.FilterFields, FilterLeafReader.FilterPostingsEnum, FilterLeafReader.FilterTerms, FilterLeafReader.FilterTermsEnum`

  ## Nested classes/interfaces inherited from class org.apache.lucene.index.IndexReader

  `IndexReader.CacheHelper, IndexReader.CacheKey, IndexReader.ClosedListener`

- ## Field Summary

  ### Fields inherited from class org.apache.lucene.index.FilterLeafReader

  `in`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `OrdinalMappingLeafReader(LeafReader in, int[] ordinalMap, FacetsConfig srcConfig)`
  Wraps an LeafReader, mapping ordinals according to the ordinalMap, using the provided `FacetsConfig` which was used to build the wrapped reader.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `IndexReader.CacheHelper`
  `getCoreCacheHelper()`
  `IndexReader.CacheHelper`
  `getReaderCacheHelper()`
  `SortedNumericDocValues`
  `getSortedNumericDocValues(String field)`

  ### Methods inherited from class org.apache.lucene.index.FilterLeafReader

  `checkIntegrity, doClose, getBinaryDocValues, getByteVectorValues, getDelegate, getDocValuesSkipper, getFieldInfos, getFloatVectorValues, getLiveDocs, getMetaData, getNormValues, getNumericDocValues, getPointValues, getSortedDocValues, getSortedSetDocValues, maxDoc, numDocs, searchNearestVectors, searchNearestVectors, storedFields, terms, termVectors, toString, unwrap`

  ### Methods inherited from class org.apache.lucene.index.LeafReader

  `docFreq, getContext, getDocCount, getLiveDocsWithDeletedIterator, getSumDocFreq, getSumTotalTermFreq, postings, postings, searchNearestVectors, searchNearestVectors, totalTermFreq`

  ### Methods inherited from class org.apache.lucene.index.IndexReader

  `close, decRef, ensureOpen, equals, getRefCount, hasDeletions, hashCode, incRef, leaves, notifyReaderClosedListeners, numDeletedDocs, registerParentReader, tryIncRef`

  ### Methods inherited from class java.lang.Object

  `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### OrdinalMappingLeafReader

    public OrdinalMappingLeafReader(LeafReader in, int[] ordinalMap, FacetsConfig srcConfig)
    Wraps an LeafReader, mapping ordinals according to the ordinalMap, using the provided `FacetsConfig` which was used to build the wrapped reader.

- ## Method Details

  - ### getSortedNumericDocValues

    public SortedNumericDocValues getSortedNumericDocValues(String field) throws IOException
    Overrides:
      `getSortedNumericDocValues` in class `FilterLeafReader`
    Throws:
      `IOException`

  - ### getCoreCacheHelper

    public IndexReader.CacheHelper getCoreCacheHelper()
    Specified by:
      `getCoreCacheHelper` in class `LeafReader`

  - ### getReaderCacheHelper

    public IndexReader.CacheHelper getReaderCacheHelper()
    Specified by:
      `getReaderCacheHelper` in class `IndexReader`