/*==========================================================================*\
| $Id: GitTreeIterator.java,v 1.2 2011/11/08 14:06:07 aallowat Exp $
|*-------------------------------------------------------------------------*|
| Copyright (C) 2011 Virginia Tech
|
| This file is part of Web-CAT.
|
| Web-CAT is free software; you can redistribute it and/or modify
| it under the terms of the GNU Affero General Public License as published
| by the Free Software Foundation; either version 3 of the License, or
| (at your option) any later version.
|
| Web-CAT is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU Affero General Public License
| along with Web-CAT; if not, see <http://www.gnu.org/licenses/>.
\*==========================================================================*/
package org.webcat.core.git;
import java.io.IOException;
import java.util.Iterator;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.CanonicalTreeParser;
import org.eclipse.jgit.treewalk.TreeWalk;
import com.webobjects.foundation.NSArray;
import com.webobjects.foundation.NSMutableArray;
//-------------------------------------------------------------------------
/**
* An iterator that iterates over a Git tree or commit object.
*
* @author Tony Allevato
* @author Last changed by $Author: aallowat $
* @version $Revision: 1.2 $, $Date: 2011/11/08 14:06:07 $
*/
public class GitTreeIterator
implements Iterator<GitTreeEntry>, Iterable<GitTreeEntry>
{
//~ Constructors ..........................................................
// ----------------------------------------------------------
/**
* Creates a new non-recursive {@code GitTreeIterator} for the specified
* tree or commit object.
*
* @param repository the repository
* @param treeOrCommitId the id of the tree or commit object
*/
public GitTreeIterator(GitRepository repository, ObjectId treeOrCommitId)
{
this(repository, treeOrCommitId, null);
}
// ----------------------------------------------------------
/**
* Creates a new non-recursive {@code GitTreeIterator} for the specified
* tree or commit object.
*
* @param repository the repository
* @param treeOrCommitId the id of the tree or commit object
* @param pathPrefix a prefix to be prepended to the paths of the returned
* entries, or null
*/
public GitTreeIterator(GitRepository repository, ObjectId treeOrCommitId,
String pathPrefix)
{
this(repository, treeOrCommitId, false);
this.pathPrefix = pathPrefix;
}
// ----------------------------------------------------------
/**
* Creates a new {@code GitTreeIterator} for the specified tree or commit
* object.
*
* @param repository the repository
* @param treeOrCommitId the id of the tree or commit object
* @param recursive true if the iterator should be recursive, otherwise
* false
*/
public GitTreeIterator(GitRepository repository, ObjectId treeOrCommitId,
boolean recursive)
{
this.repository = repository;
this.recursive = recursive;
int type = repository.typeOfObject(treeOrCommitId);
if (type == Constants.OBJ_TREE)
{
initializeFromTree(treeOrCommitId);
}
else if (type == Constants.OBJ_COMMIT || type == Constants.OBJ_TAG)
{
initializeFromCommit(treeOrCommitId);
}
else
{
treeWalk = null;
}
}
//~ Methods ...............................................................
// ----------------------------------------------------------
/**
* Gets a value indicating whether or not the iterator is recursive.
*
* @return true if the iterator is recursive, otherwise false
*/
public boolean isRecursive()
{
return recursive;
}
// ----------------------------------------------------------
/**
* Gets an array of {@link GitTreeEntry} objects that represent the entire
* contents of the tree. This method exhausts the iterator and may only be
* called on a newly-created iterator; it may not be called once
* {@link #next()} has been called.
*
* @return an {@code NSArray} containing all of the {@link GitTreeEntry}
* objects in the tree
*/
public NSArray<GitTreeEntry> allEntries()
{
if (nextWasCalled)
{
throw new IllegalStateException("allEntries() cannot be called "
+ "once next() has been called.");
}
NSMutableArray<GitTreeEntry> entries =
new NSMutableArray<GitTreeEntry>();
for (GitTreeEntry entry : this)
{
entries.addObject(entry);
}
GitUtilities.sortEntries(entries);
return entries;
}
// ----------------------------------------------------------
/**
* Releases any resources in use by the iterator.
*/
public void release()
{
if (revWalk != null)
{
revWalk.release();
}
if (treeWalk != null)
{
treeWalk.release();
}
}
// ----------------------------------------------------------
/**
* Returns this iterator. This method is provided so that the iterator
* itself can be used in a for-each loop.
*
* @return this iterator
*/
public Iterator<GitTreeEntry> iterator()
{
return this;
}
// ----------------------------------------------------------
/**
* Gets a value indicating whether or not the iterator has another entry.
*
* @return true if the iterator has another entry, or false if it does not
*/
public boolean hasNext()
{
try
{
return treeWalk != null && treeWalk.next();
}
catch (IOException e)
{
return false;
}
}
// ----------------------------------------------------------
/**
* Gets the next entry in the tree.
*
* @return a {@link GitTreeEntry} representing the next entry in the tree
*/
public GitTreeEntry next()
{
nextWasCalled = true;
return GitTreeEntry.fromTreeWalk(treeWalk, repository, pathPrefix);
}
// ----------------------------------------------------------
/**
* Removal is not supported by {@code GitTreeIterator}.
*
* @throws UnsupportedOperationException
*/
public void remove()
{
throw new UnsupportedOperationException("remove() is not supported on "
+ "GitTreeIterators.");
}
// ----------------------------------------------------------
/**
* Initializes the iterator from an object ID that represents a tree.
*
* @param treeId the tree id
*/
private void initializeFromTree(ObjectId treeId)
{
treeWalk = new TreeWalk(repository.repository());
treeWalk.setRecursive(recursive);
try
{
treeWalk.addTree(treeId);
}
catch (IOException e)
{
// Do nothing.
}
}
// ----------------------------------------------------------
/**
* Initializes the iterator from an object ID that represents a commit.
*
* @param treeId the commit id
*/
private void initializeFromCommit(ObjectId commitId)
{
revWalk = new RevWalk(repository.repository());
treeWalk = new TreeWalk(repository.repository());
treeWalk.setRecursive(recursive);
try
{
CanonicalTreeParser parser = new CanonicalTreeParser();
ObjectReader reader = repository.repository().newObjectReader();
parser.reset(reader, revWalk.parseTree(commitId));
treeWalk.addTree(parser);
}
catch (IOException e)
{
// Do nothing.
}
}
//~ Static/instance variables .............................................
private GitRepository repository;
private String pathPrefix;
private boolean recursive;
private boolean nextWasCalled;
private TreeWalk treeWalk;
private RevWalk revWalk;
}