org.apache.lucene.util.fst
Class BytesRefFSTEnum<T>

java.lang.Object
  org.apache.lucene.util.fst.BytesRefFSTEnum<T>

public final class BytesRefFSTEnum<T>
extends Object

Enumerates all input (BytesRef) + output pairs in an FST.

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

Nested Class Summary

static class

BytesRefFSTEnum.InputOutput<T> Holds a single input (BytesRef) + output pair.

Field Summary

protected FST.Arc<T>[]	arcs
protected FST<T>	fst
protected T	NO_OUTPUT
protected T[]	output
protected FST.Arc<T>	scratchArc
protected int	targetLength
protected int	upto

Constructor Summary

BytesRefFSTEnum(FST<T> fst)
doFloor controls the behavior of advance: if it's true doFloor is true, advance positions to the biggest term before target.

Method Summary

BytesRefFSTEnum.InputOutput<T>	current()
protected void	doNext()
protected void	doSeekCeil() Seeks to smallest term that's >= target.
protected boolean	doSeekExact() Seeks to exactly target term.
protected void	doSeekFloor() Seeks to largest term that's <= target.
protected int	getCurrentLabel()
protected int	getTargetLabel()
protected void	grow()
BytesRefFSTEnum.InputOutput<T>	next()
protected void	rewindPrefix() Rewinds enum state to match the shared prefix between current term and target term
BytesRefFSTEnum.InputOutput<T>	seekCeil(BytesRef target) Seeks to smallest term that's >= target.
BytesRefFSTEnum.InputOutput<T>	seekExact(BytesRef target) Seeks to exactly this term, returning null if the term doesn't exist.
BytesRefFSTEnum.InputOutput<T>	seekFloor(BytesRef target) Seeks to biggest term that's <= target.
protected void	setCurrentLabel(int label)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

fst

protected final FST<T> fst

arcs

protected FST.Arc<T>[] arcs

output

protected T[] output

NO_OUTPUT

protected final T NO_OUTPUT

scratchArc

protected final FST.Arc<T> scratchArc

upto

protected int upto

targetLength

protected int targetLength

Constructor Detail

BytesRefFSTEnum

public BytesRefFSTEnum(FST<T> fst)

doFloor controls the behavior of advance: if it's true doFloor is true, advance positions to the biggest term before target.

Method Detail

current

public BytesRefFSTEnum.InputOutput<T> current()

next

public BytesRefFSTEnum.InputOutput<T> next()
                                    throws IOException

Throws:

IOException

seekCeil

public BytesRefFSTEnum.InputOutput<T> seekCeil(BytesRef target)
                                        throws IOException

Seeks to smallest term that's >= target.

Throws:

IOException

seekFloor

public BytesRefFSTEnum.InputOutput<T> seekFloor(BytesRef target)
                                         throws IOException

Seeks to biggest term that's <= target.

Throws:

IOException

seekExact

public BytesRefFSTEnum.InputOutput<T> seekExact(BytesRef target)
                                         throws IOException

Seeks to exactly this term, returning null if the term doesn't exist. This is faster than using seekFloor(org.apache.lucene.util.BytesRef) or seekCeil(org.apache.lucene.util.BytesRef) because it short-circuits as soon the match is not found.

Throws:

IOException

getTargetLabel

protected int getTargetLabel()

getCurrentLabel

protected int getCurrentLabel()

setCurrentLabel

protected void setCurrentLabel(int label)

grow

protected void grow()

rewindPrefix

protected final void rewindPrefix()
                           throws IOException

Rewinds enum state to match the shared prefix between current term and target term

Throws:

IOException

doNext

protected void doNext()
               throws IOException

Throws:

IOException

doSeekCeil

protected void doSeekCeil()
                   throws IOException

Seeks to smallest term that's >= target.

Throws:

IOException

doSeekFloor

protected void doSeekFloor()
                    throws IOException

Seeks to largest term that's <= target.

Throws:

IOException

doSeekExact

protected boolean doSeekExact()
                       throws IOException

Seeks to exactly target term.

Throws:

IOException