org.apache.commons.jrcs.diff.myers

Class MyersDiff

java.lang.Object

org.apache.commons.jrcs.diff.myers.MyersDiff

All Implemented Interfaces:

DiffAlgorithm

public class MyersDiff
extends java.lang.Object
implements DiffAlgorithm

A clean-room implementation of Eugene Myers differencing algorithm.

See the paper at http://www.cs.arizona.edu/people/gene/PAPERS/diff.ps

Version:

$Revision: 1.7 $ $Date: 2003/10/13 08:00:24 $

Author:

Juanco Anez

See Also:

Delta, Revision, Diff

Constructor Summary

Constructors

Constructor and Description
MyersDiff() Constructs an instance of the Myers differencing algorithm.

Method Summary

Methods

Modifier and Type	Method and Description
static PathNode	buildPath(java.lang.Object[] orig, java.lang.Object[] rev) Computes the minimum diffpath that expresses de differences between the original and revised sequences, according to Gene Myers differencing algorithm.
static Revision	buildRevision(PathNode path, java.lang.Object[] orig, java.lang.Object[] rev) Constructs a Revision from a difference path.
Revision	diff(java.lang.Object[] orig, java.lang.Object[] rev) Computes the difference between the original sequence and the revised sequence and returns it as a Revision object.

Methods inherited from class java.lang.Object

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

Constructor Detail

MyersDiff

public MyersDiff()

Constructs an instance of the Myers differencing algorithm.

Method Detail

diff

public Revision diff(java.lang.Object[] orig,
            java.lang.Object[] rev)
              throws DifferentiationFailedException

Computes the difference between the original sequence and the revised sequence and returns it as a Revision object.

The revision can be used to construct the revised sequence from the original sequence.

Specified by:

diff in interface DiffAlgorithm

rev - the revised text

Returns:

the revision script.

Throws:

DifferentiationFailedException - if the diff could not be computed.

buildPath

public static PathNode buildPath(java.lang.Object[] orig,
                 java.lang.Object[] rev)
                          throws DifferentiationFailedException

Computes the minimum diffpath that expresses de differences between the original and revised sequences, according to Gene Myers differencing algorithm.

Parameters:

orig - The original sequence.

rev - The revised sequence.

Returns:

A minimum Path accross the differences graph.

Throws:

DifferentiationFailedException - if a diff path could not be found.

buildRevision

public static Revision buildRevision(PathNode path,
                     java.lang.Object[] orig,
                     java.lang.Object[] rev)

Constructs a Revision from a difference path.

Parameters:

path - The path.

orig - The original sequence.

rev - The revised sequence.

Returns:

A Revision script corresponding to the path.

Throws:

DifferentiationFailedException - if a Revision could not be built from the given path.