Module org.apache.lucene.misc

Package org.apache.lucene.misc.util.fst

Class UpToTwoPositiveIntOutputs

java.lang.Object

org.apache.lucene.util.fst.Outputs<Object>

org.apache.lucene.misc.util.fst.UpToTwoPositiveIntOutputs

public final class UpToTwoPositiveIntOutputs
extends Outputs<Object>

An FST Outputs implementation where each output is one or two non-negative long values. If it's a single output, Long is returned; else, TwoLongs. Order is preserved in the TwoLongs case, ie .first is the first input/output added to Builder, and .second is the second. You cannot store 0 output with this (that's reserved to mean "no output")!

NOTE: the only way to create a TwoLongs output is to add the same input to the FST twice in a row. This is how the FST maps a single input to two outputs (e.g. you cannot pass a TwoLongs to FSTCompiler.add(org.apache.lucene.util.IntsRef, T). If you need more than two then use ListOfOutputs, but if you only have at most 2 then this implementation will require fewer bytes as it steals one bit from each long value.

NOTE: the resulting FST is not guaranteed to be minimal! See FSTCompiler.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	UpToTwoPositiveIntOutputs.TwoLongs	Holds two long outputs.

Field Summary

Fields

Modifier and Type	Field	Description
private final boolean	doShare
private static final Long	NO_OUTPUT
private static final UpToTwoPositiveIntOutputs	singletonNoShare
private static final UpToTwoPositiveIntOutputs	singletonShare
private static final long	TWO_LONGS_NUM_BYTES

Constructor Summary

Constructors

Modifier	Constructor	Description
private	UpToTwoPositiveIntOutputs(boolean doShare)

Method Summary

Modifier and Type	Method	Description
Object	add(Object _prefix, Object _output)	Eg add("foo", "bar") -> "foobar"
Long	common(Object _output1, Object _output2)	Eg common("foobar", "food") -> "foo"
Long	get(long v)
UpToTwoPositiveIntOutputs.TwoLongs	get(long first, long second)
Object	getNoOutput()	NOTE: this output is compared with == so you must ensure that all methods return the single object if it's really no output
static UpToTwoPositiveIntOutputs	getSingleton(boolean doShare)
Object	merge(Object first, Object second)
String	outputToString(Object output)
long	ramBytesUsed(Object o)	Return memory usage for the provided output.
Object	read(DataInput in)	Decode an output value previously written with Outputs.write(Object, DataOutput).
Long	subtract(Object _output, Object _inc)	Eg subtract("foobar", "foo") -> "bar"
private boolean	valid(Long o)
private boolean	valid(Object _o, boolean allowDouble)
void	write(Object _output, DataOutput out)	Encode an output value into a DataOutput.

Methods inherited from class org.apache.lucene.util.fst.Outputs

readFinalOutput, skipFinalOutput, skipOutput, writeFinalOutput

Methods inherited from class java.lang.Object

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

Field Details

NO_OUTPUT

private static final Long NO_OUTPUT

doShare

private final boolean doShare

singletonShare

private static final UpToTwoPositiveIntOutputs singletonShare

singletonNoShare

private static final UpToTwoPositiveIntOutputs singletonNoShare

TWO_LONGS_NUM_BYTES

private static final long TWO_LONGS_NUM_BYTES

Constructor Details

UpToTwoPositiveIntOutputs

private UpToTwoPositiveIntOutputs(boolean doShare)

Method Details

getSingleton

public static UpToTwoPositiveIntOutputs getSingleton(boolean doShare)

get

public Long get(long v)

get

public UpToTwoPositiveIntOutputs.TwoLongs get(long first,
 long second)

common

public Long common(Object _output1,
 Object _output2)

Description copied from class: Outputs

Eg common("foobar", "food") -> "foo"

Specified by:

common in class Outputs<Object>

subtract

public Long subtract(Object _output,
 Object _inc)

Description copied from class: Outputs

Eg subtract("foobar", "foo") -> "bar"

Specified by:

subtract in class Outputs<Object>

add

public Object add(Object _prefix,
 Object _output)

Description copied from class: Outputs

Eg add("foo", "bar") -> "foobar"

Specified by:

add in class Outputs<Object>

write

public void write(Object _output,
 DataOutput out)
           throws IOException

Description copied from class: Outputs

Encode an output value into a DataOutput.

Specified by:

write in class Outputs<Object>

Throws:

IOException

read

public Object read(DataInput in)
            throws IOException

Description copied from class: Outputs

Decode an output value previously written with Outputs.write(Object, DataOutput).

Specified by:

read in class Outputs<Object>

Throws:

IOException

valid

private boolean valid(Long o)

valid

private boolean valid(Object _o,
 boolean allowDouble)

getNoOutput

public Object getNoOutput()

Description copied from class: Outputs

NOTE: this output is compared with == so you must ensure that all methods return the single object if it's really no output

Specified by:

getNoOutput in class Outputs<Object>

outputToString

public String outputToString(Object output)

Specified by:

outputToString in class Outputs<Object>

merge

public Object merge(Object first,
 Object second)

Overrides:

merge in class Outputs<Object>

ramBytesUsed

public long ramBytesUsed(Object o)

Description copied from class: Outputs

Return memory usage for the provided output.

Specified by:

ramBytesUsed in class Outputs<Object>

See Also:

• Accountable