org.apache.lucene.util.fst

Class Outputs<T>

java.lang.Object

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

Direct Known Subclasses:

ByteSequenceOutputs, CharSequenceOutputs, IntSequenceOutputs, NoOutputs, PairOutputs, PositiveIntOutputs

public abstract class Outputs<T>
extends Object

Represents the outputs for an FST, providing the basic algebra required for building and traversing the FST.

Note that any operation that returns NO_OUTPUT must return the same singleton object from getNoOutput().

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

Constructor Summary

Constructors

Constructor and Description
Outputs()

Method Summary

Modifier and Type	Method and Description
abstract T	add(T prefix, T output) Eg add("foo", "bar") -> "foobar"
abstract T	common(T output1, T output2) Eg common("foobar", "food") -> "foo"
abstract T	getNoOutput() NOTE: this output is compared with == so you must ensure that all methods return the single object if it's really no output
T	merge(T first, T second)
abstract String	outputToString(T output)
abstract long	ramBytesUsed(T output) Return memory usage for the provided output.
abstract T	read(DataInput in) Decode an output value previously written with write(Object, DataOutput).
T	readFinalOutput(DataInput in) Decode an output value previously written with writeFinalOutput(Object, DataOutput).
void	skipFinalOutput(DataInput in) Skip the output previously written with writeFinalOutput(T, org.apache.lucene.store.DataOutput); defaults to just calling readFinalOutput(org.apache.lucene.store.DataInput) and discarding the result.
void	skipOutput(DataInput in) Skip the output; defaults to just calling read(org.apache.lucene.store.DataInput) and discarding the result.
abstract T	subtract(T output, T inc) Eg subtract("foobar", "foo") -> "bar"
abstract void	write(T output, DataOutput out) Encode an output value into a DataOutput.
void	writeFinalOutput(T output, DataOutput out) Encode an final node output value into a DataOutput.

Methods inherited from class java.lang.Object

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

Constructor Detail

Outputs

public Outputs()

Method Detail

common

public abstract T common(T output1,
                         T output2)

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

subtract

public abstract T subtract(T output,
                           T inc)

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

add

public abstract T add(T prefix,
                      T output)

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

write

public abstract void write(T output,
                           DataOutput out)
                    throws IOException

Encode an output value into a DataOutput.

Throws:

IOException

writeFinalOutput

public void writeFinalOutput(T output,
                             DataOutput out)
                      throws IOException

Encode an final node output value into a DataOutput. By default this just calls write(Object, DataOutput).

Throws:

IOException

read

public abstract T read(DataInput in)
                throws IOException

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

Throws:

IOException

skipOutput

public void skipOutput(DataInput in)
                throws IOException

Skip the output; defaults to just calling read(org.apache.lucene.store.DataInput) and discarding the result.

Throws:

IOException

readFinalOutput

public T readFinalOutput(DataInput in)
                  throws IOException

Decode an output value previously written with writeFinalOutput(Object, DataOutput). By default this just calls read(DataInput).

Throws:

IOException

skipFinalOutput

public void skipFinalOutput(DataInput in)
                     throws IOException

Skip the output previously written with writeFinalOutput(T, org.apache.lucene.store.DataOutput); defaults to just calling readFinalOutput(org.apache.lucene.store.DataInput) and discarding the result.

Throws:

IOException

getNoOutput

public abstract T getNoOutput()

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

outputToString

public abstract String outputToString(T output)

merge

public T merge(T first,
               T second)

ramBytesUsed

public abstract long ramBytesUsed(T output)

Return memory usage for the provided output.

See Also:

Accountable