/*
* Copyright 2000-2009 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Class DiffFragmentBuilder
* @author Jeka
*/
package com.intellij.openapi.diff.impl;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.diff.ex.DiffFragment;
import com.intellij.openapi.util.TextRange;
import com.intellij.util.diff.Diff;
import java.util.LinkedList;
import java.util.List;
/**
Builds a sequence of DiffFragment objects thus diffing 2 files
Parses the output of CVS 'diff' command assumed to be in the RCS Normal Format
Format of the output chunks for the command: 'diff file1 file2':
change-command
< from-file-line
< from-file-line...
---
> to-file-line
> to-file-line...
Where:
Change-Command -> Line a Range
Change-Command -> Range c Range
Change-Command -> Range d Line
Range -> Line , Line
Range -> Line
Line -> number-of-line
The commands are:
a: append a range of lines from the file2 after line Line of the file1
c: change the range of lines in the file1 to the range from file2
d: Delete the lines in range Range from the file1; line Line is where they would have appeared in the file2 had they not been deleted
*/
public class DiffFragmentBuilder {
private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.diff.impl.DiffFragmentBuilder");
private final String[] mySource1;
private final String[] mySource2;
private int myLastLine1 = 1;
private int myLastLine2 = 1;
private final List<DiffFragment> myData = new LinkedList<DiffFragment>();
public DiffFragmentBuilder(String[] source1, String[] source2) {
mySource1 = source1;
mySource2 = source2;
init();
}
private List<DiffFragment> getFragments() {
return myData;
}
private void finish() {
String text1 = null;
String text2 = null;
if (myLastLine1 <= mySource1.length) {
text1 = concatenate(mySource1, myLastLine1, mySource1.length);
}
if (myLastLine2 <= mySource2.length) {
text2 = concatenate((mySource2), myLastLine2, mySource2.length);
}
if (text1 != null || text2 != null) {
myData.add(DiffFragment.unchanged(text1, text2));
}
}
private void init() {
myData.clear();
myLastLine1 = myLastLine2 = 1;
}
private void append(int line, TextRange range) {
LOG.debug("DiffFragmentBuilder.append(" + line + "," + range + "), modified:");
String text1 = null;
String text2 = null;
int start = range.getStartOffset();
int end = range.getEndOffset();
if (myLastLine1 <= line) {
text1 = concatenate(mySource1, myLastLine1, line);
}
if (myLastLine2 < start) {
text2 = concatenate(mySource2, myLastLine2, start - 1);
}
if (text1 != null || text2 != null) {
myData.add(DiffFragment.unchanged(text1, text2));
}
myData.add(new DiffFragment(null, concatenate(mySource2, start, end)));
myLastLine1 = line + 1;
myLastLine2 = end + 1;
}
private void change(TextRange range1, TextRange range2) {
LOG.debug("DiffFragmentBuilder.change(" + range1 + "," + range2 + ")");
String text1 = null, text2 = null;
int start1 = range1.getStartOffset();
int end1 = range1.getEndOffset();
int start2 = range2.getStartOffset();
int end2 = range2.getEndOffset();
if (myLastLine1 < start1) {
text1 = concatenate(mySource1, myLastLine1, start1 - 1);
}
if (myLastLine2 < start2) {
text2 = concatenate(mySource2, myLastLine2, start2 - 1);
}
if (text1 != null || text2 != null) {
myData.add(DiffFragment.unchanged(text1, text2));
}
myData.add(new DiffFragment(concatenate(mySource1, start1, end1),
concatenate(mySource2, start2, end2)));
myLastLine1 = end1 + 1;
myLastLine2 = end2 + 1;
}
private void delete(TextRange range, int line) {
LOG.debug("DiffFragmentBuilder.delete(" + range + "," + line + ")");
String text1 = null;
String text2 = null;
int start = range.getStartOffset();
int end = range.getEndOffset();
if (myLastLine1 < start) {
text1 = concatenate(mySource1, myLastLine1, start - 1);
}
if (myLastLine2 <= line) {
text2 = concatenate(mySource2, myLastLine2, line);
}
if (text1 != null || text2 != null) {
myData.add(DiffFragment.unchanged(text1, text2));
}
myData.add(new DiffFragment(concatenate(mySource1, start, end), null));
myLastLine1 = end + 1;
myLastLine2 = line + 1;
}
private static String concatenate(String[] strings, int start, int end) {
StringBuffer buffer = new StringBuffer();
for (int i = start - 1; i < end; i++) buffer.append(strings[i]);
return buffer.toString();
}
public DiffFragment[] buildFragments(Diff.Change change) {
while (change != null) {
if (change.inserted > 0 && change.deleted > 0) {
change(
new TextRange(change.line0 + 1, change.line0 + change.deleted),
new TextRange(change.line1 + 1, change.line1 + change.inserted)
);
}
else if (change.inserted > 0) {
append(change.line0, new TextRange(change.line1 + 1, change.line1 + change.inserted));
}
else if (change.deleted > 0) {
delete(new TextRange(change.line0 + 1, change.line0 + change.deleted), change.line1);
}
change = change.link;
}
finish();
final List<DiffFragment> fragments = getFragments();
return fragments.toArray(new DiffFragment[myData.size()]);
}
}