Merge "HistogramDiff: Convert stack recursion to heap managed queue"

This commit is contained in:
Robin Rosenberg 2014-08-02 05:35:18 -04:00 committed by Gerrit Code Review @ Eclipse.org
commit fd07ee54ef
1 changed files with 14 additions and 6 deletions

View File

@ -43,6 +43,9 @@
package org.eclipse.jgit.diff;
import java.util.ArrayList;
import java.util.List;
/**
* An extended form of Bram Cohen's patience diff algorithm.
* <p>
@ -130,15 +133,14 @@ public void setMaxChainLength(int maxLen) {
public <S extends Sequence> void diffNonCommon(EditList edits,
HashedSequenceComparator<S> cmp, HashedSequence<S> a,
HashedSequence<S> b, Edit region) {
new State<S>(edits, cmp, a, b).diffReplace(region);
new State<S>(edits, cmp, a, b).diffRegion(region);
}
private class State<S extends Sequence> {
private final HashedSequenceComparator<S> cmp;
private final HashedSequence<S> a;
private final HashedSequence<S> b;
private final List<Edit> queue = new ArrayList<Edit>();
/** Result edits we have determined that must be made to convert a to b. */
final EditList edits;
@ -151,7 +153,13 @@ private class State<S extends Sequence> {
this.edits = edits;
}
void diffReplace(Edit r) {
void diffRegion(Edit r) {
diffReplace(r);
while (!queue.isEmpty())
diff(queue.remove(queue.size() - 1));
}
private void diffReplace(Edit r) {
Edit lcs = new HistogramDiffIndex<S>(maxChainLength, cmp, a, b, r)
.findLongestCommonSequence();
if (lcs != null) {
@ -163,8 +171,8 @@ void diffReplace(Edit r) {
//
edits.add(r);
} else {
diff(r.before(lcs));
diff(r.after(lcs));
queue.add(r.after(lcs));
queue.add(r.before(lcs));
}
} else if (fallback instanceof LowLevelDiffAlgorithm) {