com.topologi.diffx.algorithm

Class DiffXFitWesyma

java.lang.Object

com.topologi.diffx.algorithm.DiffXAlgorithmBase

com.topologi.diffx.algorithm.DiffXFitWesyma

All Implemented Interfaces:

DiffXAlgorithm

public final class DiffXFitWesyma
extends DiffXAlgorithmBase

Performs the diff comparison using the LCS algorithm.

Implementation note: this algorithm effectively detects the correct changes in the sequences, but will not necessarily return events that can be serialised as well-formed XML as they stand.

Known problem in this implementation: elements that contain themselves tend to generate events that are harder to serialise as XML.

This class is said 'fit' because it will adapt the matrix to the sequences that it is being given in order to improve performance.

Note: The name of this class comes from a contracted version of the features of this algorithm, as explained below:

• Weighted, each token is has a given weight;
• Symmetrical, when possible, the algorithm will try to choose a path that is symmetrical in regards to the arrangement of the tokens;
• Matrix, this class uses a matrix for its internal representation;

This class is not synchronised.

Version:

7 April 2005

Author:

Christophe Lauret

Field Summary

Fields inherited from class com.topologi.diffx.algorithm.DiffXAlgorithmBase

length, length1, length2, sequence1, sequence2

Constructor Summary

Constructors

Constructor and Description
DiffXFitWesyma(EventSequence seq0, EventSequence seq1) Creates a new DiffXAlgorithmBase.

Method Summary

Modifier and Type	Method and Description
int	length() Returns the length of the longest common sequence.
void	process(DiffXFormatter formatter) Writes the diff sequence using the specified formatter.

Methods inherited from class com.topologi.diffx.algorithm.DiffXAlgorithmBase

getFirstSequence, getSecondSequence

Methods inherited from class java.lang.Object

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

Constructor Detail

DiffXFitWesyma

public DiffXFitWesyma(EventSequence seq0,
                      EventSequence seq1)

Creates a new DiffXAlgorithmBase.

Parameters:

seq0 - The first sequence to compare.

seq1 - The second sequence to compare.

Method Detail

length

public int length()

Returns the length of the longest common sequence.

Returns:

the length of the longest common sequence.

process

public void process(DiffXFormatter formatter)
             throws IOException

Writes the diff sequence using the specified formatter.

Parameters:

formatter - The formatter that will handle the output.

Throws:

IOException - If thrown by the formatter.