java/java-diff-utils
1
0
Fork 0
mirror of https://github.com/java-diff-utils/java-diff-utils.git synced 2026-03-13 10:11:17 +08:00
Code Issues Packages Projects Releases Wiki Activity

DiffRowGenerator updates:

Browse Source 
- unit tests
- ignore white spaces option implemented
- parametrize equalizer for diff algorithm
This commit is contained in:
dm.naumenko@gmail.com
2011-06-10 13:05:56 +00:00
parent 4638018277
commit 0216f2e1ef
6 changed files with 144 additions and 79 deletions
Download Patch File Download Diff File Expand all files Collapse all files

116
src/difflib/DiffRowGenerator.java
View File

@@ -16,27 +16,28 @@
package difflib;
import difflib.DiffRow.Tag;
import difflib.myers.Equalizer;
import java.util.*;
/**
* This class for generating DiffRows for side-by-sidy view.
* You can customize the way of generating. For example, show inline diffs on not, ignoring
* You can customize the way of generating. For example, show inline diffs on not, ignoring
* white spaces or/and blank lines and so on. All parameters for generating are optional. If you do
* not specify them, the class will use the default values.
*
*
* These values are:
* showInlineDiffs = false;
* ignoreWhiteSpaces = true;
* ignoreBlankLines = true;
* ...
*
*
* For instantiating the DiffRowGenerator you should use the its builder. Like in example
* <code>
* DiffRowGenerator generator = new DiffRowGenerator.Builder().showInlineDiffs(true).
* ignoreWhiteSpaces(true).columnWidth(100).build();
* </code>
*
*
* @author <a href="dm.naumenko@gmail.com">Dmitry Naumenko</a>
*/
public class DiffRowGenerator {
@@ -48,7 +49,8 @@ public class DiffRowGenerator {
private final String InlineOldCssClass;
private final String InlineNewCssClass;
private final int columnWidth;
private final Equalizer equalizer;
/**
* This class used for building the DiffRowGenerator.
* @author dmitry
@@ -56,24 +58,24 @@ public class DiffRowGenerator {
*/
public static class Builder {
private boolean showInlineDiffs = false;
private boolean ignoreWhiteSpaces = true;
private boolean ignoreBlankLines = true;
private boolean ignoreWhiteSpaces = false;
private boolean ignoreBlankLines = false;
private String InlineOldTag = "span";
private String InlineNewTag = "span";
private String InlineOldCssClass = "editOldInline";
private String InlineNewCssClass = "editNewInline";
private int columnWidth = 80;
/**
* Show inline diffs in generating diff rows or not.
* @param val the value to set. Default: false.
* @return builder with configured showInlineDiff parameter
* @return builder with configured showInlineDiff parameter
*/
public Builder showInlineDiffs(boolean val) {
showInlineDiffs = val;
return this;
}
/**
* Ignore white spaces in generating diff rows or not.
* @param val the value to set. Default: true.
@@ -83,7 +85,7 @@ public class DiffRowGenerator {
ignoreWhiteSpaces = val;
return this;
}
/**
* Ignore blank lines in generating diff rows or not.
* @param val the value to set. Default: true.
@@ -93,7 +95,7 @@ public class DiffRowGenerator {
ignoreBlankLines = val;
return this;
}
/**
* Set the tag used for displaying changes in the original text.
* @param tag the tag to set. Without angle brackets. Default: span.
@@ -103,7 +105,7 @@ public class DiffRowGenerator {
InlineOldTag = tag;
return this;
}
/**
* Set the tag used for displaying changes in the revised text.
* @param tag the tag to set. Without angle brackets. Default: span.
@@ -113,7 +115,7 @@ public class DiffRowGenerator {
InlineNewTag = tag;
return this;
}
/**
* Set the css class used for displaying changes in the original text.
* @param cssClass the tag to set. Without any quotes, just word. Default: editOldInline.
@@ -123,7 +125,7 @@ public class DiffRowGenerator {
InlineOldCssClass = cssClass;
return this;
}
/**
* Set the css class used for displaying changes in the revised text.
* @param cssClass the tag to set. Without any quotes, just word. Default: editNewInline.
@@ -133,7 +135,7 @@ public class DiffRowGenerator {
InlineNewCssClass = cssClass;
return this;
}
/**
* Set the column with of generated lines of original and revised texts.
* @param width the width to set. Making it < 0 doesn't have any sense. Default 80.
@@ -145,7 +147,7 @@ public class DiffRowGenerator {
}
return this;
}
/**
* Build the DiffRowGenerator. If some parameters is not set, the default values are used.
* @return the customized DiffRowGenerator
@@ -154,7 +156,7 @@ public class DiffRowGenerator {
return new DiffRowGenerator(this);
}
}
private DiffRowGenerator(Builder builder) {
showInlineDiffs = builder.showInlineDiffs;
ignoreWhiteSpaces = builder.ignoreWhiteSpaces; //
@@ -164,27 +166,47 @@ public class DiffRowGenerator {
InlineOldCssClass = builder.InlineOldCssClass;
InlineNewCssClass = builder.InlineNewCssClass;
columnWidth = builder.columnWidth; //
equalizer = new Equalizer() {
public boolean equals(Object original, Object revised) {
if (ignoreWhiteSpaces) {
original = ((String)original).trim().replaceAll("\\s+", " ");
revised = ((String)revised).trim().replaceAll("\\s+", " ");
}
return original.equals(revised);
}
};
}
/**
* Get the DiffRows describing the difference between original and revised texts using the
* given patch. Useful for displaying side-by-side diff.
*
*
* @param original the original text
* @param revised the revised text
* @param revised the revised text
* @return the DiffRows between original and revised texts
*/
public List<DiffRow> generateDiffRows(List<String> original, List<String> revised) {
return generateDiffRows(original, revised, DiffUtils.diff(original, revised));
return generateDiffRows(original, revised, DiffUtils.diff(original, revised, equalizer));
}
private List<String> removeBlankLines(List<String> lines) {
List<String> result = new ArrayList<String>();
for (String line: lines) {
if (line.trim().length() == 0) {
result.add("");
}
result.add(line);
}
return result;
}
/**
* Generates the DiffRows describing the difference between original and revised texts using the
* given patch. Useful for displaying side-by-side diff.
*
*
* @param original the original text
* @param revised the revised text
* @param patch the given patch
* @param patch the given patch
* @return the DiffRows between original and revised texts
*/
@SuppressWarnings("unchecked")
@@ -192,11 +214,11 @@ public class DiffRowGenerator {
// normalize the lines (expand tabs, escape html entities)
original = StringUtills.normalize(original);
revised = StringUtills.normalize(revised);
// wrap to the column width
original = StringUtills.wrapText(original, this.columnWidth);
revised = StringUtills.wrapText(revised, this.columnWidth);
List<DiffRow> diffRows = new ArrayList<DiffRow>();
int endPos = 0;
final List<Delta> deltaList = patch.getDeltas();
@@ -204,19 +226,19 @@ public class DiffRowGenerator {
Delta delta = deltaList.get(i);
Chunk orig = delta.getOriginal();
Chunk rev = delta.getRevised();
// We should normalize and wrap lines in deltas too.
orig.setLines(StringUtills.normalize((List<String>) orig.getLines()));
rev.setLines(StringUtills.normalize((List<String>) rev.getLines()));
orig.setLines(StringUtills.wrapText((List<String>) orig.getLines(), this.columnWidth));
rev.setLines(StringUtills.wrapText((List<String>) rev.getLines(), this.columnWidth));
// catch the equal prefix for each chunk
for (String line : original.subList(endPos, orig.getPosition())) {
diffRows.add(new DiffRow(Tag.EQUAL, line, line));
}
// Inserted DiffRow
if (delta.getClass().equals(InsertDelta.class)) {
endPos = orig.last() + 1;
@@ -225,7 +247,7 @@ public class DiffRowGenerator {
}
continue;
}
// Deleted DiffRow
if (delta.getClass().equals(DeleteDelta.class)) {
endPos = orig.last() + 1;
@@ -234,7 +256,7 @@ public class DiffRowGenerator {
}
continue;
}
if (showInlineDiffs) {
addInlineDiffs(delta);
}
@@ -257,14 +279,14 @@ public class DiffRowGenerator {
}
endPos = orig.last() + 1;
}
// Copy the final matching chunk if any.
for (String line : original.subList(endPos, original.size())) {
diffRows.add(new DiffRow(Tag.EQUAL, line, line));
}
return diffRows;
}
/**
* Add the inline diffs for given delta
* @param delta the given delta
@@ -313,12 +335,12 @@ public class DiffRowGenerator {
delta.getRevised().setLines(Arrays.asList(revResult.toString().split("\n")));
}
}
/**
* Wrap the elements in the sequence with the given tag
* @param startPosition the position from which tag should start. The counting start from a zero.
* @param endPosition the position before which tag should should be closed.
* @param tag the tag name without angle brackets, just a word
* @param endPosition the position before which tag should should be closed.
* @param tag the tag name without angle brackets, just a word
* @param cssClass the optional css class
*/
public static LinkedList<String> wrapInTag(LinkedList<String> sequence, int startPosition,
@@ -334,23 +356,23 @@ public class DiffRowGenerator {
}
tagBuilder.append(">");
String startTag = tagBuilder.toString();
tagBuilder.delete(0, tagBuilder.length());
tagBuilder.append("</");
tagBuilder.append(tag);
tagBuilder.append(">");
String endTag = tagBuilder.toString();
result.add(startPosition, startTag);
result.add(endPosition, endTag);
return result;
}
/**
* Wrap the given line with the given tag
* @param line the given line
* @param tag the tag name without angle brackets, just a word
* @param tag the tag name without angle brackets, just a word
* @param cssClass the optional css class
* @return the wrapped string
*/
@@ -365,17 +387,17 @@ public class DiffRowGenerator {
}
tagBuilder.append(">");
String startTag = tagBuilder.toString();
tagBuilder.delete(0, tagBuilder.length());
tagBuilder.append("</");
tagBuilder.append(tag);
tagBuilder.append(">");
String endTag = tagBuilder.toString();
return startTag + line + endTag;
}
/**
* The helper method for joining collections
* @param <T>

16
src/difflib/DiffUtils.java
View File

@@ -15,6 +15,7 @@
*/
package difflib;
import difflib.myers.Equalizer;
import difflib.myers.MyersDiff;
import java.util.ArrayList;
@@ -44,6 +45,21 @@ public class DiffUtils {
return DiffUtils.diff(original, revised, defaultDiffAlgorithm);
}
/**
* Compute the difference between the original and revised texts with default diff algorithm
*
* @param original the original text
* @param revised the revised text
* @param equalizer the equalizer object to replace the default compare algorithm (Object.equals)
* @return the patch describing the difference between the original and revised texts
*/
public static Patch diff(List<?> original, List<?> revised, Equalizer equalizer) {
if (equalizer != null) {
return DiffUtils.diff(original, revised, new MyersDiff(equalizer));
}
return DiffUtils.diff(original, revised, defaultDiffAlgorithm);
}
/**
* Compute the difference between the original and revised texts with given diff algorithm
*

5
src/difflib/myers/Equalizer.java Normal file
View File

@@ -0,0 +1,5 @@
package difflib.myers;
public interface Equalizer {
public boolean equals(Object original, Object revised);
}

75
src/difflib/myers/MyersDiff.java
View File

@@ -65,31 +65,44 @@ import java.util.List;
/**
* A clean-room implementation of <a href="http://www.cs.arizona.edu/people/gene/">
* Eugene Myers</a> differencing algorithm.
*
*
* <p> See the paper at <a href="http://www.cs.arizona.edu/people/gene/PAPERS/diff.ps">
* http://www.cs.arizona.edu/people/gene/PAPERS/diff.ps</a></p>
*
* @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a>
*/
public class MyersDiff implements DiffAlgorithm {
private static final Equalizer DEFAULT_EQUALIZER = new Equalizer() {
public boolean equals(Object original, Object revised) {
return original.equals(revised);
}
};
private Equalizer equalizer = DEFAULT_EQUALIZER;
/**
* Constructs an instance of the Myers differencing algorithm.
*/
public MyersDiff() {
}
public MyersDiff(Equalizer equalizer) {
this.equalizer = equalizer;
}
/**
* {@inheritDoc}
*
*
* Return empty diff if get the error while procession the difference.
*/
public Patch diff(List<?> original, List<?> revised) {
return diff(original.toArray(), revised.toArray());
}
/**
* {@inheritDoc}
*
*
* Return empty diff if get the error while procession the difference.
*/
public Patch diff(Object[] orig, Object[] rev) {
@@ -102,7 +115,7 @@ public class MyersDiff implements DiffAlgorithm {
}
return new Patch();
}
/**
* Computes the minimum diffpath that expresses de differences
* between the original and revised sequences, according
@@ -113,22 +126,22 @@ public class MyersDiff implements DiffAlgorithm {
* @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)
public 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 / 2;
final PathNode diagonal[] = new PathNode[size];
diagonal[middle + 1] = new Snake(0, -1, null);
for (int d = 0; d < MAX; d++) {
for (int k = -d; k <= d; k += 2) {
@@ -136,7 +149,7 @@ public class MyersDiff implements DiffAlgorithm {
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;
@@ -145,36 +158,40 @@ public class MyersDiff implements DiffAlgorithm {
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])) {
while (i < N && j < M && equals(orig[i], 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");
}
private boolean equals(Object orig, Object rev) {
return equalizer.equals(orig, rev);
}
/**
* Constructs a {@link Patch} from a difference path.
*
@@ -185,14 +202,14 @@ public class MyersDiff implements DiffAlgorithm {
* @throws DifferentiationFailedException if a {@link Patch} could
* not be built from the given path.
*/
public static Patch buildRevision(PathNode path, Object[] orig, Object[] rev) {
public Patch 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");
Patch patch = new Patch();
if (path.isSnake())
path = path.prev;
@@ -201,11 +218,11 @@ public class MyersDiff implements DiffAlgorithm {
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;
Chunk original = new Chunk(ianchor, copyOfRange(orig, ianchor, i));
Chunk revised = new Chunk(janchor, copyOfRange(rev, janchor, j));
Delta delta = null;
@@ -216,23 +233,23 @@ public class MyersDiff implements DiffAlgorithm {
} else {
delta = new ChangeDelta(original, revised);
}
patch.addDelta(delta);
if (path.isSnake())
path = path.prev;
}
return patch;
}
/**
* Copied here from JDK 1.6
*/
@SuppressWarnings("unchecked")
public static <T> T[] copyOfRange(T[] original, int from, int to) {
return copyOfRange(original, from, to, (Class<T[]>) original.getClass());
}
/**
* Copied here from JDK 1.6
*/
@@ -247,5 +264,5 @@ public class MyersDiff implements DiffAlgorithm {
System.arraycopy(original, from, copy, 0, Math.min(original.length - from, newLength));
return copy;
}
}