OnHeapFSTStore

java.lang.Object

org.apache.lucene.util.fst.OnHeapFSTStore

All Implemented Interfaces:: Accountable, FSTReader

public final class OnHeapFSTStore extends Object implements FSTReader

Provides storage of finite state machine (FST), using byte array or byte store allocated on heap.

Field Summary

Fields

Modifier and Type

Field

Description

private static final long

BASE_RAM_BYTES_USED

private final byte[]

bytesArray

Used at read time when the FST fits into a single byte[].

private ReadWriteDataOutput

dataOutput

A ReadWriteDataOutput, used during reading when the FST is very large (more than 1 GB).

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

Constructors

Constructor

Description

OnHeapFSTStore(int maxBlockBits, DataInput in, long numBytes)
Method Summary

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.

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

Field Details
- BASE_RAM_BYTES_USED
  
  private static final long BASE_RAM_BYTES_USED
- dataOutput
  
  private ReadWriteDataOutput dataOutput
  
  A ReadWriteDataOutput, used during reading when the FST is very large (more than 1 GB). If the FST is less than 1 GB then bytesArray is set instead.
- bytesArray
  
  private final byte[] bytesArray
  
  Used at read time when the FST fits into a single byte[].
Constructor Details
- OnHeapFSTStore
  
  public OnHeapFSTStore(int maxBlockBits, DataInput in, long numBytes) throws IOException
  
  Throws:
  
  IOException
Method Details
- 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
- 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