+ * See the Visitor pattern in "Design Patterns" by the GOF4.
+ * @param visitor The visitor.
+ */
+ public abstract void accept(RevisionVisitor visitor);
+}
diff --git a/source/org/apache/commons/jrcs/diff/Diff.java b/source/org/apache/commons/jrcs/diff/Diff.java
new file mode 100644
index 0000000..0353d26
--- /dev/null
+++ b/source/org/apache/commons/jrcs/diff/Diff.java
@@ -0,0 +1,344 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ *
Within this library, the word text means a unit of information + * subject to version control. + * + *
Text is represented as Object[] because
+ * the diff engine is capable of handling more than plain ascci. In fact,
+ * arrays of any type that implements
+ * {@link java.lang.Object#hashCode hashCode()} and
+ * {@link java.lang.Object#equals equals()}
+ * correctly can be subject to differencing using this
+ * library.
This library provides a framework in which different differencing + * algorithms may be used. If no algorithm is specififed, a default + * algorithm is used.
+ * + * @version $Revision: 1.1 $ $Date: 2003/07/14 12:22:29 $ + * @author Juanco Anez + * @see Delta + * @see DiffAlgorithm + * + * modifications: + * + * 27 Apr 2003 bwm + * + * Added some comments whilst trying to figure out the algorithm + * + * 03 May 2003 bwm + * + * Factored out the algorithm implementation into a separate difference + * algorithm class to allow pluggable algorithms. + */ + +public class Diff + extends ToString +{ + /** The standard line separator. */ + public static final String NL = System.getProperty("line.separator"); + + /** The line separator to use in RCS format output. */ + public static final String RCS_EOL = "\n"; + + /** The original sequence. */ + protected final Object[] orig; + + /** The differencing algorithm to use. */ + protected DiffAlgorithm algorithm; + + /** + * Create a differencing object using the default algorithm + * + * @param the original text that will be compared + */ + public Diff(Object[] original) + { + this(original, null); + } + + /** + * Create a differencing object using the given algorithm + * + * @param o the original text which will be compared against + * @param algorithm the difference algorithm to use. + */ + public Diff(Object[] original, DiffAlgorithm algorithm) + { + if (original == null) + { + throw new IllegalArgumentException(); + } + + this.orig = original; + if (algorithm != null) + this.algorithm = algorithm; + else + this.algorithm = defaultAlgorithm(); + } + + protected DiffAlgorithm defaultAlgorithm() + { + return new MyersDiff(); + } + + /** + * compute the difference between an original and a revision. + * + * @param orig the original + * @param rev the revision to compare with the original. + * @return a Revision describing the differences + */ + public static Revision diff(Object[] orig, Object[] rev) + throws DifferentiationFailedException + { + if (orig == null || rev == null) + { + throw new IllegalArgumentException(); + } + + return diff(orig, rev, null); + } + + /** + * compute the difference between an original and a revision. + * + * @param orig the original + * @param rev the revision to compare with the original. + * @param algorithm the difference algorithm to use + * @return a Revision describing the differences + */ + public static Revision diff(Object[] orig, Object[] rev, + DiffAlgorithm algorithm) + throws DifferentiationFailedException + { + if (orig == null || rev == null) + { + throw new IllegalArgumentException(); + } + + return new Diff(orig, algorithm).diff(rev); + } + + /** + * compute the difference between the original and a revision. + * + * @param rev the revision to compare with the original. + * @return a Revision describing the differences + */ + public Revision diff(Object[] rev) + throws DifferentiationFailedException + { + return algorithm.diff(orig, rev); + } + + /** + * Compares the two input sequences. + * @param orig The original sequence. + * @param rev The revised sequence. + * @return true if the sequences are identical. False otherwise. + */ + public static boolean compare(Object[] orig, Object[] rev) + { + if (orig.length != rev.length) + { + return false; + } + else + { + for (int i = 0; i < orig.length; i++) + { + if (!orig[i].equals(rev[i])) + { + return false; + } + } + return true; + } + } + + /** + * Converts an array of {@link Object Object} to a string + * using {@link Diff#NL Diff.NL} + * as the line separator. + * @param o the array of objects. + */ + public static String arrayToString(Object[] o) + { + return arrayToString(o, Diff.NL); + } + + /** + * Edits all of the items in the input sequence. + * @param text The input sequence. + * @return A sequence of the same length with all the lines + * differing from the corresponding ones in the input. + */ + public static Object[] editAll(Object[] text) + { + Object[] result = new String[text.length]; + + for(int i = 0; i < text.length; i++) + result[i] = text[i] + "
+ * The revision can be used to construct the revised sequence
+ * from the original sequence.
+ *
+ * @param rev the revised text
+ * @return the revision script.
+ * @throws DifferentiationFailedException if the diff could not be computed.
+ */
+ public abstract Revision diff(Object[] orig, Object[] rev)
+ throws DifferentiationFailedException;
+}
\ No newline at end of file
diff --git a/source/org/apache/commons/jrcs/diff/DiffException.java b/source/org/apache/commons/jrcs/diff/DiffException.java
new file mode 100644
index 0000000..069ff59
--- /dev/null
+++ b/source/org/apache/commons/jrcs/diff/DiffException.java
@@ -0,0 +1,79 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ *
+ * + * @date $Date: 2003/07/14 12:22:29 $ + * @version $Revision: 1.1 $ + * @author Juanco Anez + * + *
Overview of Algorithm
+ * + *by bwm + *
+ * + *The algorithm is optimised for situations where the input sequences + * have few repeated objects. If it is given input with many repeated + * objects it will report sub-optimal changes. However, given appropriate + * input, it is fast, and linear in memory usage.
+ * + *The algorithm consists of the following steps:
+ *The first step is to compute a an equivalence set for the input data. + * The equivalence set is computed from objects that are in the original + * input sequence
+ *+ * eq(x) = the index of the first occurence of x in the original sequence. + *+ * + *
With this equivalence function, the algorithm can compare integers rather + * than strings, which is considerably more efficient.
+ * + *The second step is to compute the datastructure on which the + * algorithm will operate. Having computed the equivalence function + * in the previous step, we can compute two arrays where + * indx[i] = eqs(orig[i]) and jndx[i] = eqs(rev[i]). The algorithm can + * now operate on indx and jndx instead of orig and rev. Thus, comparisons + * are then on O(int == int) instead of O(Object.equals(Object)). + *
+ * + *The algorithm now matches indx and jndx. Whilst indx[i] == jndx[i] + * it skips matching objects in the sequence. In seeking to match objects + * in the input sequence it assumes that each object is likely to be unique. + * It uses the known characteristics of the unique equivalence function. It can + * tell from the eq value if this object appeared in the other sequence + * at all. If it did not, there is no point in searching for a match.
+ * + *Recall that the eq function value is the index earliest occurrence in + * the orig sequence. This information is used to search efficiently for + * the next match. The algorithm is perfect when all input objects are + * unique, but degrades when input objects are not unique. When input + * objects are not unique an optimal match may not be found, but a + * correct match will be.
+ * + *Having identified common matching objects in the orig and revised + * sequences, the differences between them are easily computed. + *
+ * + * @see Delta + * @see Revision + * Modifications: + * + * 27/Apr/2003 bwm + * Added some comments whilst trying to figure out the algorithm + * + * 03 May 2003 bwm + * Created this implementation class by refactoring it out of the Diff + * class to enable plug in difference algorithms + * + */ +public class SimpleDiff + implements DiffAlgorithm +{ + + static final int NOT_FOUND_i = -2; + static final int NOT_FOUND_j = -1; + static final int EOS = Integer.MAX_VALUE; + + public SimpleDiff() + { + } + + protected int scan(int[] ndx, int i, int target) + { + while (ndx[i] < target) + { + i++; + } + return i; + } + + /** + * Compute the difference between original and revised sequences. + * + * @param orig The original sequence. + * @param rev The revised sequence to be compared with the original. + * @return A Revision object describing the differences. + * @throws DifferenciationFailedException if the diff could not be computed. + */ + public Revision diff(Object[] orig, Object[] rev) + throws DifferentiationFailedException + { + // create map eqs, such that for each item in both orig and rev + // eqs(item) = firstOccurrence(item, orig); + Map eqs = buildEqSet(orig, rev); + + // create an array such that + // indx[i] = NOT_FOUND_i if orig[i] is not in rev + // indx[i] = firstOccurrence(orig[i], orig) + int[] indx = buildIndex(eqs, orig, NOT_FOUND_i); + + // create an array such that + // jndx[j] = NOT_FOUND_j if orig[j] is not in rev + // jndx[j] = firstOccurrence(rev[j], orig) + int[] jndx = buildIndex(eqs, rev, NOT_FOUND_j); + + // what in effect has been done is to build a unique hash + // for each item that is in both orig and rev + // and to label each item in orig and new with that hash value + // or a marker that the item is not common to both. + + eqs = null; // let gc know we're done with this + + Revision deltas = new Revision(); //!!! new Revision() + int i = 0; + int j = 0; + + // skip matching + // skip leading items that are equal + // could be written + // for (i=0; indx[i] != EOS && indx[i] == jndx[i]; i++); + // j = i; + for (; indx[i] != EOS && indx[i] == jndx[j]; i++, j++) + { + /* void */ + } + + while (indx[i] != jndx[j]) + { // only equal if both == EOS + // they are different + int ia = i; + int ja = j; + + // size of this delta + do + { + // look down rev for a match + // stop at a match + // or if the FO(rev[j]) > FO(orig[i]) + // or at the end + while (jndx[j] < 0 || jndx[j] < indx[i]) + { + j++; + } + // look down orig for a match + // stop at a match + // or if the FO(orig[i]) > FO(rev[j]) + // or at the end + while (indx[i] < 0 || indx[i] < jndx[j]) + { + i++; + } + + // this doesn't do a compare each line with each other line + // so it won't find all matching lines + } + while (indx[i] != jndx[j]); + + // on exit we have a match + + // they are equal, reverse any exedent matches + // it is possible to overshoot, so count back matching items + while (i > ia && j > ja && indx[i - 1] == jndx[j - 1]) + { + --i; + --j; + } + + deltas.addDelta(Delta.newDelta(new Chunk(orig, ia, i - ia), + new Chunk(rev, ja, j - ja))); + // skip matching + for (; indx[i] != EOS && indx[i] == jndx[j]; i++, j++) + { + /* void */ + } + } + return deltas; + } + + /** + * create aMap from each common item in orig and rev
+ * to the index of its first occurrence in orig
+ *
+ * @param orig the original sequence of items
+ * @param rev the revised sequence of items
+ */
+ protected Map buildEqSet(Object[] orig, Object[] rev)
+ {
+ // construct a set of the objects that orig and rev have in common
+
+ // first construct a set containing all the elements in orig
+ Set items = new HashSet(Arrays.asList(orig));
+
+ // then remove all those not in rev
+ items.retainAll(Arrays.asList(rev));
+
+ Map eqs = new HashMap();
+ for (int i = 0; i < orig.length; i++)
+ {
+ // if its a common item and hasn't been found before
+ if (items.contains(orig[i]))
+ {
+ // add it to the map
+ eqs.put(orig[i], new Integer(i));
+ // and make sure its not considered again
+ items.remove(orig[i]);
+ }
+ }
+ return eqs;
+ }
+
+ /**
+ * build a an array such each a[i] = eqs([i]) or NF if eqs([i]) undefined
+ *
+ * @param eqs a mapping from Object to Integer
+ * @param seq a sequence of objects
+ * @param NF the not found marker
+ */
+ protected int[] buildIndex(Map eqs, Object[] seq, int NF)
+ {
+ int[] result = new int[seq.length + 1];
+ for (int i = 0; i < seq.length; i++)
+ {
+ Integer value = (Integer) eqs.get(seq[i]);
+ if (value == null || value.intValue() < 0)
+ {
+ result[i] = NF;
+ }
+ else
+ {
+ result[i] = value.intValue();
+ }
+ }
+ result[seq.length] = EOS;
+ return result;
+ }
+
+}
diff --git a/source/org/apache/commons/jrcs/diff/myers/DiffNode.java b/source/org/apache/commons/jrcs/diff/myers/DiffNode.java
new file mode 100644
index 0000000..45fd8f0
--- /dev/null
+++ b/source/org/apache/commons/jrcs/diff/myers/DiffNode.java
@@ -0,0 +1,57 @@
+package org.apache.commons.jrcs.diff.myers;
+
+/**
+ * Title:
+ *Description:
+ *Copyright: Copyright (c) 2002
+ *Company:
+ * @author not attributable + * @version 1.0 + */ + +/** + * A diffnode in a diffpath. + *+ * A DiffNode and its previous node mark a delta between + * two input sequences, that is, two differing subsequences + * between (possibly zero length) matching sequences. + * + * {@link DiffNode DiffNodes} and {@link Snake Snakes} allow for compression + * of diffpaths, as each snake is represented by a single {@link Snake Snake} + * node and each contiguous series of insertions and deletions is represented + * by a single {@link DiffNode DiffNodes}. + * + * @version $Revision: 1.1 $ $Date: 2003/07/14 12:22:29 $ + * @author Juanco Anez + * + */ +public final class DiffNode + extends PathNode +{ + /** + * Constructs a DiffNode. + *
+ * DiffNodes are compressed. That means that
+ * the path pointed to by the prev parameter
+ * will be followed using {@link PathNode#previousSnake}
+ * until a non-diff node is found.
+ *
+ * @param the position in the original sequence
+ * @param the position in the revised sequence
+ * @param prev the previous node in the path.
+ */
+ public DiffNode(int i, int j, PathNode prev)
+ {
+ super(i, j, (prev == null ? null : prev.previousSnake()) );
+ }
+
+ /**
+ * {@inheritDoc}
+ * @return false, always
+ */
+ public boolean isSnake()
+ {
+ return false;
+ }
+
+}
\ No newline at end of file
diff --git a/source/org/apache/commons/jrcs/diff/myers/MyersDiff.java b/source/org/apache/commons/jrcs/diff/myers/MyersDiff.java
new file mode 100644
index 0000000..32ebb1f
--- /dev/null
+++ b/source/org/apache/commons/jrcs/diff/myers/MyersDiff.java
@@ -0,0 +1,222 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation. All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ *
+ * See the paper at
+ *
+ * http://www.cs.arizona.edu/people/gene/PAPERS/diff.ps
+ *
+ * @version $Revision: 1.1 $ $Date: 2003/07/14 12:22:30 $
+ * @author Juanco Anez
+ * @see Delta
+ * @see Revision
+ * @see Diff
+ */
+public class MyersDiff
+ implements DiffAlgorithm
+{
+ /**
+ * Constructs an instance of the Myers differencing algorithm.
+ */
+ public MyersDiff()
+ {
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public Revision diff(Object[] orig, Object[] rev)
+ throws DifferentiationFailedException
+ {
+ PathNode path = buildPath(orig, rev);
+ return buildRevision(path, orig, rev);
+ }
+
+ /**
+ * Computes the minimum diffpath that expresses de differences
+ * between the original and revised sequences, according
+ * to Gene Myers differencing algorithm.
+ *
+ * @param orig The original sequence.
+ * @param rev The revised sequence.
+ * @return A minimum {@link PathNode Path} accross the differences graph.
+ * @throws DifferentiationFailedException if a diff path could not be found.
+ */
+ public static PathNode buildPath(Object[] orig, Object[] rev)
+ throws DifferentiationFailedException
+ {
+ if (orig == null)
+ throw new IllegalArgumentException("original sequence is null");
+ if (rev == null)
+ throw new IllegalArgumentException("revised sequence is null");
+
+ // these are local constants
+ final int N = orig.length;
+ final int M = rev.length;
+
+ final int MAX = N + M + 1;
+ final int size = 1 + 2 * MAX;
+ final int middle = (size + 1) / 2;
+ final PathNode diagonal[] = new PathNode[size];
+
+ PathNode path = null;
+
+ diagonal[middle + 1] = new Snake(0, -1, null);
+ for (int d = 0; d < MAX; d++)
+ {
+ for (int k = -d; k <= d; k += 2)
+ {
+ final int kmiddle = middle + k;
+ final int kplus = kmiddle + 1;
+ final int kminus = kmiddle - 1;
+ PathNode prev = null;
+
+ int i;
+ if ( (k == -d) ||
+ (k != d && diagonal[kminus].i < diagonal[kplus].i))
+ {
+ i = diagonal[kplus].i;
+ prev = diagonal[kplus];
+ }
+ else
+ {
+ i = diagonal[kminus].i + 1;
+ prev = diagonal[kminus];
+ }
+
+ diagonal[kminus] = null; // no longer used
+
+ int j = i - k;
+
+ PathNode node = new DiffNode(i, j, prev);
+
+ // orig and rev are zero-based
+ // but the algorithm is one-based
+ // that's why there's no +1 when indexing the sequences
+ while (i < N && j < M && orig[i].equals(rev[j]))
+ {
+ i++;
+ j++;
+ }
+ if (i > node.i)
+ node = new Snake(i, j, node);
+
+ diagonal[kmiddle] = node;
+
+ if (i >= N && j >= M)
+ {
+ return diagonal[kmiddle];
+ }
+ }
+ diagonal[middle+d-1] = null;
+
+ }
+ // According to Myers, this cannot happen
+ throw new DifferentiationFailedException("could not find a diff path");
+ }
+
+ /**
+ * Constructs a {@link Revision} from a difference path.
+ *
+ * @param path The path.
+ * @param orig The original sequence.
+ * @param rev The revised sequence.
+ * @return A {@link Revision} script corresponding to the path.
+ * @throws DifferentiationFailedException if a {@link Revision} could
+ * not be built from the given path.
+ */
+ public static Revision buildRevision(PathNode path, Object[] orig, Object[] rev)
+ {
+ if (path == null)
+ throw new IllegalArgumentException("path is null");
+ if (orig == null)
+ throw new IllegalArgumentException("original sequence is null");
+ if (rev == null)
+ throw new IllegalArgumentException("revised sequence is null");
+
+ Revision revision = new Revision();
+ if (path.isSnake())
+ path = path.prev;
+ while (path != null && path.prev != null && path.prev.j >= 0)
+ {
+ if(path.isSnake())
+ throw new IllegalStateException("bad diffpath: found snake when looking for diff");
+ int i = path.i;
+ int j = path.j;
+
+ path = path.prev;
+ int ianchor = path.i;
+ int janchor = path.j;
+
+ Delta delta = Delta.newDelta(new Chunk(orig, ianchor, i - ianchor),
+ new Chunk(rev, janchor, j - janchor));
+ revision.insertDelta(delta);
+ if (path.isSnake())
+ path = path.prev;
+ }
+ return revision;
+ }
+
+}
diff --git a/source/org/apache/commons/jrcs/diff/myers/PathNode.java b/source/org/apache/commons/jrcs/diff/myers/PathNode.java
new file mode 100644
index 0000000..99ba15a
--- /dev/null
+++ b/source/org/apache/commons/jrcs/diff/myers/PathNode.java
@@ -0,0 +1,146 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ *
+ * In bottstrap nodes one of the two corrdinates is
+ * less than zero.
+ * @return tru if this is a bootstrap node.
+ */
+ public boolean isBootstrap()
+ {
+ return i < 0 || j < 0;
+ }
+
+ /**
+ * Skips sequences of {@link DiffNode DiffNodes} until a
+ * {@link Snake} or bootstrap node is found, or the end
+ * of the path is reached.
+ * @return The next first {@link Snake} or bootstrap node in the path, or
+ * null
+ * if none found.
+ */
+ public final PathNode previousSnake()
+ {
+ if (isBootstrap())
+ return null;
+ if (!isSnake() && prev != null)
+ return prev.previousSnake();
+ return this;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public String toString()
+ {
+ StringBuffer buf = new StringBuffer("[");
+ PathNode node = this;
+ while (node != null)
+ {
+ buf.append("(");
+ buf.append(Integer.toString(node.i));
+ buf.append(",");
+ buf.append(Integer.toString(node.j));
+ buf.append(")");
+ node = node.prev;
+ }
+ buf.append("]");
+ return buf.toString();
+ }
+}
\ No newline at end of file
diff --git a/source/org/apache/commons/jrcs/diff/myers/Snake.java b/source/org/apache/commons/jrcs/diff/myers/Snake.java
new file mode 100644
index 0000000..46c1d69
--- /dev/null
+++ b/source/org/apache/commons/jrcs/diff/myers/Snake.java
@@ -0,0 +1,97 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ *
+ *
+ * {@link DiffNode DiffNodes} and {@link Snake Snakes} allow for compression
+ * of diffpaths, as each snake is represented by a single {@link Snake Snake}
+ * node and each contiguous series of insertions and deletions is represented
+ * by a single {@link DiffNode DiffNodes}.
+ *
+ * @version $Revision: 1.1 $ $Date: 2003/07/14 12:22:30 $
+ * @author Juanco Anez
+ *
+ */
+public final class Snake
+ extends PathNode
+{
+ /**
+ * Constructs a snake node.
+ *
+ * @param the position in the original sequence
+ * @param the position in the revised sequence
+ * @param prev the previous node in the path.
+ */
+ public Snake(int i, int j, PathNode prev)
+ {
+ super(i, j, prev);
+ }
+
+ /**
+ * {@inheritDoc}
+ * @return true always
+ */
+ public boolean isSnake()
+ {
+ return true;
+ }
+
+}
\ No newline at end of file
diff --git a/source/org/apache/commons/jrcs/tools/JDiff.java b/source/org/apache/commons/jrcs/tools/JDiff.java
new file mode 100644
index 0000000..c41a847
--- /dev/null
+++ b/source/org/apache/commons/jrcs/tools/JDiff.java
@@ -0,0 +1,153 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ *
JDiff produces the deltas between the two given files in Unix diff + * format. + *
+ *The program was written as a simple test of the
+ * {@linkplain org.apache.commons.jrcs.diff diff} package.
+ */
+public class JDiff
+{
+
+ static final String[] loadFile(String name) throws IOException
+ {
+ BufferedReader data = new BufferedReader(new FileReader(name));
+ List lines = new ArrayList();
+ String s;
+ while ((s = data.readLine()) != null)
+ {
+ lines.add(s);
+ }
+ return (String[])lines.toArray(new String[lines.size()]);
+ }
+
+ static final void usage(String name)
+ {
+ System.err.println("Usage: " + name + " file1 file2");
+ }
+
+ public static void main(String[] argv) throws Exception
+ {
+ if (argv.length < 2)
+ {
+ usage("JDiff");
+ System.exit(2); // THDL modification
+ }
+ else
+ {
+ Object[] orig = loadFile(argv[0]);
+ Object[] rev = loadFile(argv[1]);
+
+ Diff df = new Diff(orig);
+ Revision r = df.diff(rev);
+ if (r.size() == 0) // THDL modification
+ System.exit(0); // THDL modification
+
+ System.err.println("------");
+ System.out.print(r.toString());
+ System.err.println("------" + new Date());
+
+ try
+ {
+ Object[] reco = r.patch(orig);
+ //String recos = Diff.arrayToString(reco);
+ if (!Diff.compare(rev, reco))
+ {
+ System.err.println("INTERNAL ERROR:"
+ + "files differ after patching!");
+ }
+ }
+ catch (Throwable o)
+ {
+ System.out.println("Patch failed");
+ }
+ System.exit(1); // THDL modification
+ }
+ }
+
+ /** THDL modification -- returns the Revision that gets you from
+ file x to file y, or null on error. */
+ public static Revision getDiff(String x, String y)
+ {
+ try {
+ Object[] orig = loadFile(x);
+ Object[] rev = loadFile(y);
+
+ Diff df = new Diff(orig);
+ return df.diff(rev);
+ } catch (Exception e) {
+ return null;
+ }
+ }
+}
+
diff --git a/source/org/apache/commons/jrcs/util/ToString.java b/source/org/apache/commons/jrcs/util/ToString.java
new file mode 100644
index 0000000..fda3240
--- /dev/null
+++ b/source/org/apache/commons/jrcs/util/ToString.java
@@ -0,0 +1,154 @@
+/*
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999-2003 The Apache Software Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ * any, must include the following acknowlegement:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowlegement may appear in the software itself,
+ * if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ * Foundation" must not be used to endorse or promote products derived
+ * from this software without prior written permission. For written
+ * permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ * nor may "Apache" appear in their names without prior written
+ * permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ * line.separator system property
+ * as the linebreak character.
+ * @param value the string to convert.
+ */
+ public static String[] stringToArray(String value)
+ {
+ BufferedReader reader = new BufferedReader(new StringReader(value));
+ List l = new LinkedList();
+ String s;
+ try
+ {
+ while ((s = reader.readLine()) != null)
+ {
+ l.add(s);
+ }
+ }
+ catch (java.io.IOException e)
+ {
+ }
+ return (String[]) l.toArray(new String[l.size()]);
+ }
+
+ /**
+ * Converts an array of {@link Object Object} to a string
+ * Use the value of the line.separator system property
+ * the line separator.
+ * @param o the array of objects.
+ */
+ public static String arrayToString(Object[] o)
+ {
+ return arrayToString(o, System.getProperty("line.separator"));
+ }
+
+ /**
+ * Converts an array of {@link Object Object} to a string
+ * using the given line separator.
+ * @param o the array of objects.
+ * @param EOL the string to use as line separator.
+ */
+ public static String arrayToString(Object[] o, String EOL)
+ {
+ StringBuffer buf = new StringBuffer();
+ for (int i = 0; i < o.length - 1; i++)
+ {
+ buf.append(o[i]);
+ buf.append(EOL);
+ }
+ buf.append(o[o.length - 1]);
+ return buf.toString();
+ }
+}
+