CachedOrdinalsReader (Lucene 8.5.1 API)

java.lang.Object
- org.apache.lucene.facet.taxonomy.OrdinalsReader
- - org.apache.lucene.facet.taxonomy.CachedOrdinalsReader

All Implemented Interfaces:

Accountable
```
public class CachedOrdinalsReader
extends OrdinalsReader
implements Accountable
```
A per-segment cache of documents' facet ordinals. Every CachedOrdinalsReader.CachedOrds holds the ordinals in a raw int[], and therefore consumes as much RAM as the total number of ordinals found in the segment, but saves the CPU cost of decoding ordinals during facet counting.
NOTE: every CachedOrdinalsReader.CachedOrds is limited to 2.1B total ordinals. If that is a limitation for you then consider limiting the segment size to fewer documents, or use an alternative cache which pages through the category ordinals.
NOTE: when using this cache, it is advised to use a DocValuesFormat that does not cache the data in memory, at least for the category lists fields, or otherwise you'll be doing double-caching.
NOTE: create one instance of this and re-use it for all facet implementations (the cache is per-instance, not static).

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class CachedOrdinalsReader.CachedOrds
Holds the cached ordinals in two parallel int[] arrays.
- Nested classes/interfaces inherited from class org.apache.lucene.facet.taxonomy.OrdinalsReader
  OrdinalsReader.OrdinalsSegmentReader

Constructor Summary

Constructors
Constructor Description

CachedOrdinalsReader(OrdinalsReader source)
Sole constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Collection<Accountable>`	`getChildResources()`
`String`	`getIndexFieldName()`	Returns the indexed field name this `OrdinalsReader` is reading from.
`OrdinalsReader.OrdinalsSegmentReader`	`getReader(LeafReaderContext context)`	Set current atomic reader.
`long`	`ramBytesUsed()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CachedOrdinalsReader
```
public CachedOrdinalsReader(OrdinalsReader source)
```
    Sole constructor.
- Method Detail
  - getIndexFieldName
```
public String getIndexFieldName()
```
    Description copied from class: OrdinalsReader
    
    Returns the indexed field name this OrdinalsReader is reading from.
    
    Specified by:
    
    getIndexFieldName in class OrdinalsReader
  - getReader
```
public OrdinalsReader.OrdinalsSegmentReader getReader(LeafReaderContext context)
                                               throws IOException
```
    Description copied from class: OrdinalsReader
    
    Set current atomic reader.
    
    Specified by:
    
    getReader in class OrdinalsReader
    
    Throws:
    
    IOException
  - ramBytesUsed
```
public long ramBytesUsed()
```
    Specified by:
    
    ramBytesUsed in interface Accountable
  - getChildResources
```
public Collection<Accountable> getChildResources()
```
    Specified by:
    
    getChildResources in interface Accountable