/*
* Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
* Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
* Copyright (C) 2006, Shawn O. Pearce <spearce@spearce.org>
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - 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.
*
* - Neither the name of the Git Development Community nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS 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 COPYRIGHT OWNER OR
* 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.
*/
package org.spearce.jgit.lib;
import java.io.File;
import java.io.IOException;
import org.spearce.jgit.lib.GitIndex.Entry;
/**
* A class for traversing the index and one or two trees.
*
* A visitor is invoked for executing actions, like figuring out how to merge.
*/
public class IndexTreeWalker {
private final Tree mainTree;
private final Tree newTree;
private final File root;
private final IndexTreeVisitor visitor;
private boolean threeTrees;
/**
* Construct a walker for the index and one tree.
*
* @param index
* @param tree
* @param root
* @param visitor
*/
public IndexTreeWalker(GitIndex index, Tree tree, File root, IndexTreeVisitor visitor) {
this.mainTree = tree;
this.root = root;
this.visitor = visitor;
this.newTree = null;
threeTrees = false;
indexMembers = index.getMembers();
}
/**
* Construct a walker for the index and two trees.
*
* @param index
* @param mainTree
* @param newTree
* @param root
* @param visitor
*/
public IndexTreeWalker(GitIndex index, Tree mainTree, Tree newTree, File root, IndexTreeVisitor visitor) {
this.mainTree = mainTree;
this.newTree = newTree;
this.root = root;
this.visitor = visitor;
threeTrees = true;
indexMembers = index.getMembers();
}
Entry[] indexMembers;
int indexCounter = 0;
/**
* Actually walk the index tree
*
* @throws IOException
*/
public void walk() throws IOException {
walk(mainTree, newTree);
}
private void walk(Tree tree, Tree auxTree) throws IOException {
TreeIterator mi = new TreeIterator(tree, TreeIterator.Order.POSTORDER);
TreeIterator ai = new TreeIterator(auxTree, TreeIterator.Order.POSTORDER);
TreeEntry m = mi.hasNext() ? mi.next() : null;
TreeEntry a = ai.hasNext() ? ai.next() : null;
int curIndexPos = indexCounter;
Entry i = indexCounter < indexMembers.length ? indexMembers[indexCounter++] : null;
while (m != null || a != null || i != null) {
int cmpma = compare(m, a);
int cmpmi = compare(m, i);
int cmpai = compare(a, i);
TreeEntry pm = cmpma <= 0 && cmpmi <= 0 ? m : null;
TreeEntry pa = cmpma >= 0 && cmpai <= 0 ? a : null;
Entry pi = cmpmi >= 0 && cmpai >= 0 ? i : null;
if (pi != null)
visitEntry(pm, pa, pi);
else
finishVisitTree(pm, pa, curIndexPos);
if (pm != null) m = mi.hasNext() ? mi.next() : null;
if (pa != null) a = ai.hasNext() ? ai.next() : null;
if (pi != null) i = indexCounter < indexMembers.length ? indexMembers[indexCounter++] : null;
}
}
private void visitEntry(TreeEntry t1, TreeEntry t2,
Entry i) throws IOException {
assert t1 != null || t2 != null || i != null : "Needs at least one entry";
assert root != null : "Needs workdir";
if (t1 != null && t1.getParent() == null)
t1 = null;
if (t2 != null && t2.getParent() == null)
t2 = null;
File f = null;
if (i != null)
f = new File(root, i.getName());
else if (t1 != null)
f = new File(root, t1.getFullName());
else if (t2 != null)
f = new File(root, t2.getFullName());
if (t1 != null || t2 != null || i != null)
if (threeTrees)
visitor.visitEntry(t1, t2, i, f);
else
visitor.visitEntry(t1, i, f);
}
private void finishVisitTree(TreeEntry t1, TreeEntry t2, int curIndexPos)
throws IOException {
assert t1 != null || t2 != null : "Needs at least one entry";
assert root != null : "Needs workdir";
if (t1 != null && t1.getParent() == null)
t1 = null;
if (t2 != null && t2.getParent() == null)
t2 = null;
File f = null;
String c= null;
if (t1 != null) {
c = t1.getFullName();
f = new File(root, c);
} else if (t2 != null) {
c = t2.getFullName();
f = new File(root, c);
}
if (t1 instanceof Tree || t2 instanceof Tree)
if (threeTrees)
visitor.finishVisitTree((Tree)t1, (Tree)t2, c);
else
visitor.finishVisitTree((Tree)t1, indexCounter - curIndexPos, c);
else if (t1 != null || t2 != null)
if (threeTrees)
visitor.visitEntry(t1, t2, null, f);
else
visitor.visitEntry(t1, null, f);
}
static boolean lt(TreeEntry h, Entry i) {
return compare(h, i) < 0;
}
static boolean lt(Entry i, TreeEntry t) {
return compare(t, i) > 0;
}
static boolean lt(TreeEntry h, TreeEntry m) {
return compare(h, m) < 0;
}
static boolean eq(TreeEntry t1, TreeEntry t2) {
return compare(t1, t2) == 0;
}
static boolean eq(TreeEntry t1, Entry e) {
return compare(t1, e) == 0;
}
static int compare(TreeEntry t, Entry i) {
if (t == null && i == null)
return 0;
if (t == null)
return 1;
if (i == null)
return -1;
return Tree.compareNames(t.getFullNameUTF8(), i.getNameUTF8(), TreeEntry.lastChar(t), TreeEntry.lastChar(i));
}
static int compare(TreeEntry t1, TreeEntry t2) {
if (t1 != null && t1.getParent() == null && t2 != null && t2.getParent() == null)
return 0;
if (t1 != null && t1.getParent() == null)
return -1;
if (t2 != null && t2.getParent() == null)
return 1;
if (t1 == null && t2 == null)
return 0;
if (t1 == null)
return 1;
if (t2 == null)
return -1;
return Tree.compareNames(t1.getFullNameUTF8(), t2.getFullNameUTF8(), TreeEntry.lastChar(t1), TreeEntry.lastChar(t2));
}
}