de.spieleck.app.ngramj
Class NGramImpl

java.lang.Object
  de.spieleck.app.ngramj.NGramImpl

All Implemented Interfaces:

NGram

public class NGramImpl
extends java.lang.Object
implements NGram

Class to modell a concrete and simple NGram.

To make it slightly more interestion (and efficient), those NGrams follow a Flyweight pattern! I.e. of each different NGram there will only be one instance in the System. This is a bit technical, but one can safely ignore this and just deliberately call newNGram().

Version:

$Revision: 2 $ $Date: 2006-03-27 23:00:21 +0200 (Mo, 27 Mrz 2006) $ $Author: nestefan $

Author:

Christiaan Fluit, Frank S. Nestel, $Author: nestefan $

Field Summary

protected byte[]	bytes
protected static NGramImpl[]	known
protected static int	knownCount
protected static int	knownStep
protected int	size

Constructor Summary

protected

NGramImpl()

Method Summary

static int	appendCode(int h, byte b) scrambler for hashcodes...
static int	code(byte[] bytes, int start, int length) Encode a byte sequence.
boolean	equals(byte[] bytes, int start, int length) Compare a ngram to a bunch of bytes
int	getByte(int pos) Return a single byte of the NGram.
static int	getKnownCount()
NGramImpl	getNGramImpl() Hand out a special representation of yourself
static int	getNGramImplCount()
int	getSize() Return the size of the ngram.
int	hashCode() Override the hashCode by s.th. that allows to hash NGrams against tiny byte sequences.
static NGram	newNGram(byte[] bytes, int start) QuasiConstructor.
static NGram	newNGram(byte[] bytes, int start, int length) QuasiConstructor.
static NGram	newNGram(byte[] bytes, int start, int length, boolean cacheObject)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

bytes

protected byte[] bytes

size

protected int size

known

protected static NGramImpl[] known

knownCount

protected static int knownCount

knownStep

protected static int knownStep

Constructor Detail

NGramImpl

protected NGramImpl()

Method Detail

newNGram

public static NGram newNGram(byte[] bytes,
                             int start)

QuasiConstructor. FlyWeight means that we first have to look if we allready know the current beasty.

newNGram

public static NGram newNGram(byte[] bytes,
                             int start,
                             int length)

QuasiConstructor. FlyWeight means that we first have to look if we allready know the current beasty.

newNGram

public static NGram newNGram(byte[] bytes,
                             int start,
                             int length,
                             boolean cacheObject)

getSize

public int getSize()

Return the size of the ngram.

Specified by:

getSize in interface NGram

getByte

public int getByte(int pos)

Return a single byte of the NGram.

Specified by:

getByte in interface NGram

Throws:

ArrayIndexOutOfBoundException - ...

getKnownCount

public static int getKnownCount()

equals

public boolean equals(byte[] bytes,
                      int start,
                      int length)

Description copied from interface: NGram

Compare a ngram to a bunch of bytes

Specified by:

equals in interface NGram

hashCode

public int hashCode()

Override the hashCode by s.th. that allows to hash NGrams against tiny byte sequences.

Overrides:

hashCode in class java.lang.Object

code

public static int code(byte[] bytes,
                       int start,
                       int length)

Encode a byte sequence.

appendCode

public static final int appendCode(int h,
                                   byte b)

scrambler for hashcodes...

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getNGramImpl

public NGramImpl getNGramImpl()

Description copied from interface: NGram

Hand out a special representation of yourself

Specified by:

getNGramImpl in interface NGram

getNGramImplCount

public static int getNGramImplCount()