Package org.apache.pinot.segment.local.utils.nativefst.builder

Class FSTSerializerImpl

java.lang.Object

org.apache.pinot.segment.local.utils.nativefst.builder.FSTSerializerImpl

All Implemented Interfaces:

FSTSerializer

public final class FSTSerializerImpl
extends Object
implements FSTSerializer

Serializes a physical FST graphs to a binary format compatible with Jan Daciuk's fsa's package ImmutableFST format.

It is possible to serialize the automaton with numbers required for perfect hashing. See withNumbers() method.

See Also:

ImmutableFST, FST.read(java.io.InputStream)

Field Summary

Fields

Modifier and Type	Field	Description
byte	_annotationByte
byte	_fillerByte

Constructor Summary

Constructors

Constructor	Description
FSTSerializerImpl()

Method Summary

Modifier and Type	Method	Description
Set<FSTFlags>	getFlags()	Return supported flags.
<T extends OutputStream> T	serialize(FST fst, T os)	Serialize root state s to an output stream in ImmutableFST format.
FSTSerializerImpl	withNumbers()	Serialize the automaton with the number of right-language sequences in each node.

Methods inherited from class java.lang.Object

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

Field Detail

_fillerByte

public byte _fillerByte

See Also:

ImmutableFST._filler

_annotationByte

public byte _annotationByte

See Also:

ImmutableFST._annotation

Constructor Detail

FSTSerializerImpl

public FSTSerializerImpl()

Method Detail

withNumbers

public FSTSerializerImpl withNumbers()

Serialize the automaton with the number of right-language sequences in each node. This is required to implement perfect hashing. The numbering also preserves the order of input sequences.

Specified by:

withNumbers in interface FSTSerializer

Returns:

Returns the same object for easier call chaining.

serialize

public <T extends OutputStream> T serialize(FST fst,
                                            T os)
                                     throws IOException

Serialize root state s to an output stream in ImmutableFST format.

Specified by:

serialize in interface FSTSerializer

Type Parameters:

T - A subclass of OutputStream, returned for chaining.

Parameters:

fst - The automaton to serialize.

os - The output stream to serialize to.

Returns:

Returns os for chaining.

Throws:

IOException - Rethrown if an I/O error occurs.

See Also:

withNumbers()

getFlags

public Set<FSTFlags> getFlags()

Return supported flags.

Specified by:

getFlags in interface FSTSerializer

Returns:

Returns the set of flags supported by the serializer (and the output automaton).