OffHeapFSTStore (Lucene 9.12.0 core API)

java.lang.Object
- org.apache.lucene.util.fst.OffHeapFSTStore

All Implemented Interfaces:

Accountable, FSTReader
```
public final class OffHeapFSTStore
extends Object
implements FSTReader
```
Provides off heap storage of finite state machine (FST), using underlying index input instead of byte store on heap

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

Field Summary
- Fields inherited from interface org.apache.lucene.util.Accountable
  NULL_ACCOUNTABLE

Constructor Summary

Constructors
Constructor Description

OffHeapFSTStore(IndexInput in, long offset, FST.FSTMetadata<?> metadata)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`FST.BytesReader`	`getReverseBytesReader()`	Get the reverse BytesReader for this FST
`long`	`ramBytesUsed()`	Return the memory usage of this object in bytes.
`long`	`size()`
`void`	`writeTo(DataOutput out)`	Write this FST to another DataOutput

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

Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources

- Constructor Detail
  - OffHeapFSTStore
```
public OffHeapFSTStore(IndexInput in,
                       long offset,
                       FST.FSTMetadata<?> metadata)
```
- Method Detail
  - ramBytesUsed
```
public long ramBytesUsed()
```
    Description copied from interface: Accountable
    
    Return the memory usage of this object in bytes. Negative values are illegal.
    
    Specified by:
    
    ramBytesUsed in interface Accountable
  - size
```
public long size()
```
  - getReverseBytesReader
```
public FST.BytesReader getReverseBytesReader()
```
    Description copied from interface: FSTReader
    
    Get the reverse BytesReader for this FST
    
    Specified by:
    
    getReverseBytesReader in interface FSTReader
    
    Returns:
    
    the reverse BytesReader
  - writeTo
```
public void writeTo(DataOutput out)
             throws IOException
```
    Description copied from interface: FSTReader
    
    Write this FST to another DataOutput
    
    Specified by:
    
    writeTo in interface FSTReader
    
    Parameters:
    
    out - the DataOutput
    
    Throws:
    
    IOException - if exception occurred during writing