morfologik.fsa

Class FSA5

java.lang.Object

morfologik.fsa.FSA

morfologik.fsa.FSA5

All Implemented Interfaces:

java.lang.Iterable<java.nio.ByteBuffer>

public final class FSA5
extends FSA

FSA binary format implementation for version 5.

Version 5 indicates the dictionary was built with these flags: FSAFlags.FLEXIBLE, FSAFlags.STOPBIT and FSAFlags.NEXTBIT. The internal representation of the FSA must therefore follow this description (please note this format describes only a single transition (arc), not the entire dictionary file).

 ---- this node header present only if automaton was compiled with NUMBERS option.
 Byte
        +-+-+-+-+-+-+-+-+\
      0 | | | | | | | | | \  LSB
        +-+-+-+-+-+-+-+-+  +
      1 | | | | | | | | |  |      number of strings recognized
        +-+-+-+-+-+-+-+-+  +----- by the automaton starting
        : : : : : : : : :  |      from this node.
        +-+-+-+-+-+-+-+-+  +
  ctl-1 | | | | | | | | | /  MSB
        +-+-+-+-+-+-+-+-+/
        
 ---- remaining part of the node
 
 Byte
       +-+-+-+-+-+-+-+-+\
     0 | | | | | | | | | +------ label
       +-+-+-+-+-+-+-+-+/
 
                  +------------- node pointed to is next
                  | +----------- the last arc of the node
                  | | +--------- the arc is final
                  | | |
             +-----------+
             |    | | |  |
         ___+___  | | |  |
        /       \ | | |  |
       MSB           LSB |
        7 6 5 4 3 2 1 0  |
       +-+-+-+-+-+-+-+-+ |
     1 | | | | | | | | | \ \
       +-+-+-+-+-+-+-+-+  \ \  LSB
       +-+-+-+-+-+-+-+-+     +
     2 | | | | | | | | |     |
       +-+-+-+-+-+-+-+-+     |
     3 | | | | | | | | |     +----- target node address (in bytes)
       +-+-+-+-+-+-+-+-+     |      (not present except for the byte
       : : : : : : : : :     |       with flags if the node pointed to
       +-+-+-+-+-+-+-+-+     +       is next)
   gtl | | | | | | | | |    /  MSB
       +-+-+-+-+-+-+-+-+   /
 gtl+1                           (gtl = gotoLength)
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	ADDRESS_OFFSET An offset in the arc structure, where the address and flags field begins.
byte	annotation Annotation character.
byte[]	arcs An array of bytes with the internal representation of the automaton.
static int	BIT_FINAL_ARC Bit indicating that an arc corresponds to the last character of a sequence available when building the automaton.
static int	BIT_LAST_ARC Bit indicating that an arc is the last one of the node's list and the following one belongs to another node.
static int	BIT_TARGET_NEXT Bit indicating that the target node of this arc follows it in the compressed automaton structure (no goto field).
static byte	DEFAULT_ANNOTATION Default annotation byte.
static byte	DEFAULT_FILLER Default filler byte.
byte	filler Filler character.
private java.util.Set<FSAFlags>	flags Flags for this automaton version.
int	gtl Number of bytes each address takes in full, expanded form (goto length).
int	nodeDataLength The length of the node header structure (if the automaton was compiled with NUMBERS option).
static byte	VERSION Automaton version as in the file header.

Constructor Summary

Constructors

Constructor and Description
FSA5(java.io.InputStream stream) Read and wrap a binary automaton in FSA version 5.

Method Summary

Modifier and Type	Method and Description
(package private) static int	decodeFromBytes(byte[] arcs, int start, int n) Returns an n-byte integer encoded in byte-packed representation.
int	getArc(int node, byte label)
byte	getArcLabel(int arc)
(package private) int	getDestinationNodeOffset(int arc) Returns the address of the node pointed to by this arc.
int	getEndNode(int arc)
int	getFirstArc(int node)
java.util.Set<FSAFlags>	getFlags()
int	getNextArc(int arc)
int	getRightLanguageCount(int node) Returns the number encoded at the given node.
int	getRootNode() Returns the start node of this automaton.
boolean	isArcFinal(int arc)
boolean	isArcLast(int arc) Returns true if this arc has NEXT bit set.
boolean	isArcTerminal(int arc)
boolean	isNextSet(int arc)
private int	skipArc(int offset) Read the arc's layout and skip as many bytes, as needed.

Methods inherited from class morfologik.fsa.FSA

getArcCount, getSequences, getSequences, iterator, read, read, readRemaining, visitAllStates, visitInPostOrder, visitInPostOrder, visitInPreOrder, visitInPreOrder

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

DEFAULT_FILLER

public static final byte DEFAULT_FILLER

Default filler byte.

See Also:

Constant Field Values

DEFAULT_ANNOTATION

public static final byte DEFAULT_ANNOTATION

Default annotation byte.

See Also:

Constant Field Values

VERSION

public static final byte VERSION

Automaton version as in the file header.

See Also:

Constant Field Values

BIT_FINAL_ARC

public static final int BIT_FINAL_ARC

Bit indicating that an arc corresponds to the last character of a sequence available when building the automaton.

See Also:

Constant Field Values

BIT_LAST_ARC

public static final int BIT_LAST_ARC

Bit indicating that an arc is the last one of the node's list and the following one belongs to another node.

See Also:

Constant Field Values

BIT_TARGET_NEXT

public static final int BIT_TARGET_NEXT

Bit indicating that the target node of this arc follows it in the compressed automaton structure (no goto field).

See Also:

Constant Field Values

ADDRESS_OFFSET

public static final int ADDRESS_OFFSET

An offset in the arc structure, where the address and flags field begins. In version 5 of FSA automata, this value is constant (1, skip label).

See Also:

Constant Field Values

arcs

public final byte[] arcs

An array of bytes with the internal representation of the automaton. Please see the documentation of this class for more information on how this structure is organized.

nodeDataLength

public final int nodeDataLength

The length of the node header structure (if the automaton was compiled with NUMBERS option). Otherwise zero.

flags

private java.util.Set<FSAFlags> flags

Flags for this automaton version.

gtl

public final int gtl

Number of bytes each address takes in full, expanded form (goto length).

filler

public final byte filler

Filler character.

annotation

public final byte annotation

Annotation character.

Constructor Detail

FSA5

FSA5(java.io.InputStream stream)
throws java.io.IOException

Read and wrap a binary automaton in FSA version 5.

Throws:

java.io.IOException

Method Detail

getRootNode

public int getRootNode()

Returns the start node of this automaton.

Specified by:

getRootNode in class FSA

Returns:

Returns the identifier of the root node of this automaton. Returns 0 if the start node is also the end node (the automaton is empty).

getFirstArc

public final int getFirstArc(int node)

Specified by:

getFirstArc in class FSA

Parameters:

node - Identifier of the node.

Returns:

Returns the identifier of the first arc leaving node or 0 if the node has no outgoing arcs.

getNextArc

public final int getNextArc(int arc)

Specified by:

getNextArc in class FSA

Parameters:

arc - The arc's identifier.

Returns:

Returns the identifier of the next arc after arc and leaving node. Zero is returned if no more arcs are available for the node.

getArc

public int getArc(int node,
                  byte label)

Specified by:

getArc in class FSA

Parameters:

node - Identifier of the node.

label - The arc's label.

Returns:

Returns the identifier of an arc leaving node and labeled with label. An identifier equal to 0 means the node has no outgoing arc labeled label.

getEndNode

public int getEndNode(int arc)

Specified by:

getEndNode in class FSA

Parameters:

arc - The arc's identifier.

Returns:

Return the end node pointed to by a given arc. Terminal arcs (those that point to a terminal state) have no end node representation and throw a runtime exception.

getArcLabel

public byte getArcLabel(int arc)

Specified by:

getArcLabel in class FSA

Parameters:

arc - The arc's identifier.

Returns:

Return the label associated with a given arc.

isArcFinal

public boolean isArcFinal(int arc)

Specified by:

isArcFinal in class FSA

Parameters:

arc - The arc's identifier.

Returns:

Returns true if the destination node at the end of this arc corresponds to an input sequence created when building this automaton.

isArcTerminal

public boolean isArcTerminal(int arc)

Specified by:

isArcTerminal in class FSA

Parameters:

arc - The arc's identifier.

Returns:

Returns true if this arc does not have a terminating node (@link FSA.getEndNode(int) will throw an exception). Implies FSA.isArcFinal(int).

getRightLanguageCount

public int getRightLanguageCount(int node)

Returns the number encoded at the given node. The number equals the count of the set of suffixes reachable from node (called its right language).

Overrides:

getRightLanguageCount in class FSA

Parameters:

node - Identifier of the node.

Returns:

Returns the number of sequences reachable from the given state if the automaton was compiled with FSAFlags.NUMBERS. The size of the right language of the state, in other words.

getFlags

public java.util.Set<FSAFlags> getFlags()

For this automaton version, an additional FSAFlags.NUMBERS flag may be set to indicate the automaton contains extra fields for each node.

Specified by:

getFlags in class FSA

Returns:

Returns a set of flags for this FSA instance.

isArcLast

public boolean isArcLast(int arc)

Returns true if this arc has NEXT bit set.

Parameters:

arc - The node's arc identifier.

Returns:

Returns true if the argument is the last arc of a node.

See Also:

BIT_LAST_ARC

isNextSet

public boolean isNextSet(int arc)

Parameters:

arc - The node's arc identifier.

Returns:

Returns true if BIT_TARGET_NEXT is set for this arc.

See Also:

BIT_TARGET_NEXT

decodeFromBytes

static final int decodeFromBytes(byte[] arcs,
                                 int start,
                                 int n)

Returns an n-byte integer encoded in byte-packed representation.

getDestinationNodeOffset

final int getDestinationNodeOffset(int arc)

Returns the address of the node pointed to by this arc.

skipArc

private int skipArc(int offset)

Read the arc's layout and skip as many bytes, as needed.