CFSA2

java.lang.Object
- morfologik.fsa.FSA
- - morfologik.fsa.CFSA2

All Implemented Interfaces:: java.lang.Iterable<java.nio.ByteBuffer>

public final class CFSA2
extends FSA

CFSA (Compact Finite State Automaton) binary format implementation, version 2:

BIT_TARGET_NEXT applicable on all arcs, not necessarily the last one.
v-coded goto field
v-coded perfect hashing numbers, if any
31 most frequent labels integrated with flags byte

The encoding of automaton body is as follows.

 ---- CFSA header
 Byte                            Description 
       +-+-+-+-+-+-+-+-+\
     0 | | | | | | | | | +------ '\'
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     1 | | | | | | | | | +------ 'f'
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     2 | | | | | | | | | +------ 's'
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     3 | | | | | | | | | +------ 'a'
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     4 | | | | | | | | | +------ version (fixed 0xc6)
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     5 | | | | | | | | | +----\
       +-+-+-+-+-+-+-+-+/      \ flags [MSB first]
       +-+-+-+-+-+-+-+-+\      /
     6 | | | | | | | | | +----/
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     7 | | | | | | | | | +------ label lookup table size
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
  8-32 | | | | | | | | | +------ label value lookup table 
       : : : : : : : : : |
       +-+-+-+-+-+-+-+-+/
 
 ---- Start of a node; only if automaton was compiled with NUMBERS option.
 
 Byte
        +-+-+-+-+-+-+-+-+\
      0 | | | | | | | | | \  
        +-+-+-+-+-+-+-+-+  +
      1 | | | | | | | | |  |      number of strings recognized
        +-+-+-+-+-+-+-+-+  +----- by the automaton starting
        : : : : : : : : :  |      from this node. v-coding
        +-+-+-+-+-+-+-+-+  +
        | | | | | | | | | /  
        +-+-+-+-+-+-+-+-+/

 ---- A vector of this node's arcs. An arc's layout depends on the combination of flags.
 
 1) NEXT bit set, mapped arc label. 
 
        +----------------------- node pointed to is next
        | +--------------------- the last arc of the node
        | | +------------------- this arc leads to a final state (acceptor)
        | | |  _______+--------- arc's label; indexed if M > 0, otherwise explicit label follows
        | | | / | | | |
       +-+-+-+-+-+-+-+-+\
     0 |N|L|F|M|M|M|M|M| +------ flags + (M) index of the mapped label.
       +-+-+-+-+-+-+-+-+/
       +-+-+-+-+-+-+-+-+\
     1 | | | | | | | | | +------ optional label if M == 0
       +-+-+-+-+-+-+-+-+/
       : : : : : : : : :
       +-+-+-+-+-+-+-+-+\
       |A|A|A|A|A|A|A|A| +------ v-coded goto address
       +-+-+-+-+-+-+-+-+/

Field Summary

Fields
Modifier and Type	Field and Description
`byte[]`	`arcs` An array of bytes with the internal representation of the automaton.
`static int`	`BIT_FINAL_ARC` The arc corresponds to the last character of a sequence available when building the automaton (acceptor transition).
`static int`	`BIT_LAST_ARC` The arc is the last one from the current node's arcs list.
`static int`	`BIT_TARGET_NEXT` The target node of this arc follows the last arc of the current state (no goto field).
`private int`	`epsilon` Epsilon node's offset.
`private java.util.EnumSet<FSAFlags>`	`flags` Flags for this automaton version.
`private boolean`	`hasNumbers` If `true` states are prepended with numbers.
`(package private) static int`	`LABEL_INDEX_BITS` The count of bits assigned to storing an indexed label.
`(package private) static int`	`LABEL_INDEX_MASK` Masks only the M bits of a flag byte.
`static int`	`LABEL_INDEX_SIZE` Maximum size of the labels index.
`byte[]`	`labelMapping` Label mapping for M-indexed labels.
`static byte`	`VERSION` Automaton header version value.

Constructor Summary

Constructors
Constructor and Description

CFSA2(java.io.InputStream stream)
Reads an automaton from a byte stream.

Constructors
Constructor and Description
`CFSA2(java.io.InputStream stream)` Reads an automaton from a byte stream.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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)`
`int`	`getRootNode()`
`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)`
`(package private) static int`	`readVInt(byte[] array, int offset)` Read a v-int.
`private int`	`skipArc(int offset)` Read the arc's layout and skip as many bytes, as needed, to skip it.
`private int`	`skipVInt(int offset)` Skip a v-int.
`(package private) static int`	`vIntLength(int value)` Return the byte-length of a v-coded int.

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
  - VERSION
```
public static final byte VERSION
```
    Automaton header version value.
    
    See Also:
    
    Constant Field Values
  - BIT_TARGET_NEXT
```
public static final int BIT_TARGET_NEXT
```
    The target node of this arc follows the last arc of the current state (no goto field).
    
    See Also:
    
    Constant Field Values
  - BIT_LAST_ARC
```
public static final int BIT_LAST_ARC
```
    The arc is the last one from the current node's arcs list.
    
    See Also:
    
    Constant Field Values
  - BIT_FINAL_ARC
```
public static final int BIT_FINAL_ARC
```
    The arc corresponds to the last character of a sequence available when building the automaton (acceptor transition).
    
    See Also:
    
    Constant Field Values
  - LABEL_INDEX_BITS
```
static final int LABEL_INDEX_BITS
```
    The count of bits assigned to storing an indexed label.
    
    See Also:
    
    Constant Field Values
  - LABEL_INDEX_MASK
```
static final int LABEL_INDEX_MASK
```
    Masks only the M bits of a flag byte.
    
    See Also:
    
    Constant Field Values
  - LABEL_INDEX_SIZE
```
public static final int LABEL_INDEX_SIZE
```
    Maximum size of the labels index.
    
    See Also:
    
    Constant Field Values
  - arcs
```
public 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.
  - flags
```
private final java.util.EnumSet<FSAFlags> flags
```
    Flags for this automaton version.
  - labelMapping
```
public final byte[] labelMapping
```
    Label mapping for M-indexed labels.
  - hasNumbers
```
private final boolean hasNumbers
```
    If true states are prepended with numbers.
  - epsilon
```
private final int epsilon
```
    Epsilon node's offset.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - CFSA2
```
CFSA2(java.io.InputStream stream)
throws java.io.IOException
```
    Reads an automaton from a byte stream.
    
    Throws:
    
    java.io.IOException
- Method Detail
  - getRootNode
```
public int getRootNode()
```
    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.
  - getRightLanguageCount
```
public int getRightLanguageCount(int node)
```
    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.
  - 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).
  - 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
  - getFlags
```
public java.util.Set<FSAFlags> getFlags()
```
    Specified by:
    
    getFlags in class FSA
    
    Returns:
    
    Returns a set of flags for this FSA instance.
  - 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, to skip it.
  - readVInt
```
static int readVInt(byte[] array,
                    int offset)
```
    Read a v-int.
  - vIntLength
```
static int vIntLength(int value)
```
    Return the byte-length of a v-coded int.
  - skipVInt
```
private int skipVInt(int offset)
```
    Skip a v-int.

Class CFSA2

Field Summary

Constructor Summary

Method Summary

Methods inherited from class morfologik.fsa.FSA

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Field Detail

VERSION

BIT_TARGET_NEXT

BIT_LAST_ARC

BIT_FINAL_ARC

LABEL_INDEX_BITS

LABEL_INDEX_MASK

LABEL_INDEX_SIZE

arcs

flags

labelMapping

hasNumbers

epsilon

Constructor Detail

CFSA2

Method Detail

getRootNode

getFirstArc

getNextArc

getArc

getEndNode

getArcLabel

getRightLanguageCount

isArcFinal

isArcTerminal

isArcLast

isNextSet

getFlags

getDestinationNodeOffset

skipArc

readVInt

vIntLength

skipVInt