org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheIterator.java - jgit/jgit - Gitiles

 /*
  * Copyright (C) 2008-2009, Google Inc.
  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
  * under the terms of the Eclipse Distribution License v1.0 which
  * accompanies this distribution, is reproduced below, and is
  * available at http://www.eclipse.org/org/documents/edl-v10.php
  *
  * 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 Eclipse Foundation, Inc. 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.eclipse.jgit.dircache;

 import java.io.IOException;
 import java.util.Arrays;

 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.treewalk.AbstractTreeIterator;
 import org.eclipse.jgit.treewalk.EmptyTreeIterator;

 /**
  * Iterate a {@link DirCache} as part of a <code>TreeWalk</code>.
  * <p>
  * This is an iterator to adapt a loaded <code>DirCache</code> instance (such as
  * read from an existing <code>.git/index</code> file) to the tree structure
  * used by a <code>TreeWalk</code>, making it possible for applications to walk
  * over any combination of tree objects already in the object database, index
  * files, or working directories.
  *
  * @see org.eclipse.jgit.treewalk.TreeWalk
  */
 public class DirCacheIterator extends AbstractTreeIterator {
 	/** The cache this iterator was created to walk. */
 	protected final DirCache cache;

 	/** The tree this iterator is walking. */
 	private final DirCacheTree tree;

 	/** First position in this tree. */
 	private final int treeStart;

 	/** Last position in this tree. */
 	private final int treeEnd;

 	/** Special buffer to hold the ObjectId of {@link #currentSubtree}. */
 	private final byte[] subtreeId;

 	/** Index of entry within {@link #cache}. */
 	protected int ptr;

 	/** Next subtree to consider within {@link #tree}. */
 	private int nextSubtreePos;

 	/** The current file entry from {@link #cache}. */
 	protected DirCacheEntry currentEntry;

 	/** The subtree containing {@link #currentEntry} if this is first entry. */
 	protected DirCacheTree currentSubtree;

 	/**
 	 * Create a new iterator for an already loaded DirCache instance.
 	 * <p>
 	 * The iterator implementation may copy part of the cache's data during
 	 * construction, so the cache must be read in prior to creating the
 	 * iterator.
 	 *
 	 * @param dc
 	 *            the cache to walk. It must be already loaded into memory.
 	 */
 	public DirCacheIterator(final DirCache dc) {
 		cache = dc;
 		tree = dc.getCacheTree(true);
 		treeStart = 0;
 		treeEnd = tree.getEntrySpan();
 		subtreeId = new byte[Constants.OBJECT_ID_LENGTH];
 		if (!eof())
 			parseEntry();
 	}

 	DirCacheIterator(final DirCacheIterator p, final DirCacheTree dct) {
 		super(p, p.path, p.pathLen + 1);
 		cache = p.cache;
 		tree = dct;
 		treeStart = p.ptr;
 		treeEnd = treeStart + tree.getEntrySpan();
 		subtreeId = p.subtreeId;
 		ptr = p.ptr;
 		parseEntry();
 	}

 	@Override
 	public AbstractTreeIterator createSubtreeIterator(final Repository repo)
 			throws IncorrectObjectTypeException, IOException {
 		if (currentSubtree == null)
 			throw new IncorrectObjectTypeException(getEntryObjectId(),
 					Constants.TYPE_TREE);
 		return new DirCacheIterator(this, currentSubtree);
 	}

 	@Override
 	public EmptyTreeIterator createEmptyTreeIterator() {
 		final byte[] n = new byte[Math.max(pathLen + 1, DEFAULT_PATH_SIZE)];
 		System.arraycopy(path, 0, n, 0, pathLen);
 		n[pathLen] = '/';
 		return new EmptyTreeIterator(this, n, pathLen + 1);
 	}

 	@Override
 	public byte[] idBuffer() {
 		if (currentSubtree != null)
 			return subtreeId;
 		if (currentEntry != null)
 			return currentEntry.idBuffer();
 		return zeroid;
 	}

 	@Override
 	public int idOffset() {
 		if (currentSubtree != null)
 			return 0;
 		if (currentEntry != null)
 			return currentEntry.idOffset();
 		return 0;
 	}

 	@Override
 	public boolean first() {
 		return ptr == treeStart;
 	}

 	@Override
 	public boolean eof() {
 		return ptr == treeEnd;
 	}

 	@Override
 	public void next(int delta) {
 		while (--delta >= 0) {
 			if (currentSubtree != null)
 				ptr += currentSubtree.getEntrySpan();
 			else
 				ptr++;
 			if (eof())
 				break;
 			parseEntry();
 		}
 	}

 	@Override
 	public void back(int delta) {
 		while (--delta >= 0) {
 			if (currentSubtree != null)
 				nextSubtreePos--;
 			ptr--;
 			parseEntry();
 			if (currentSubtree != null)
 				ptr -= currentSubtree.getEntrySpan() - 1;
 		}
 	}

 	private void parseEntry() {
 		currentEntry = cache.getEntry(ptr);
 		final byte[] cep = currentEntry.path;

 		if (nextSubtreePos != tree.getChildCount()) {
 			final DirCacheTree s = tree.getChild(nextSubtreePos);
 			if (s.contains(cep, pathOffset, cep.length)) {
 				// The current position is the first file of this subtree.
 				// Use the subtree instead as the current position.
 				//
 				currentSubtree = s;
 				nextSubtreePos++;

 				if (s.isValid())
 					s.getObjectId().copyRawTo(subtreeId, 0);
 				else
 					Arrays.fill(subtreeId, (byte) 0);
 				mode = FileMode.TREE.getBits();
 				path = cep;
 				pathLen = pathOffset + s.nameLength();
 				return;
 			}
 		}

 		// The current position is a file/symlink/gitlink so we
 		// do not have a subtree located here.
 		//
 		mode = currentEntry.getRawMode();
 		path = cep;
 		pathLen = cep.length;
 		currentSubtree = null;
 	}

 	/**
 	 * Get the DirCacheEntry for the current file.
 	 *
 	 * @return the current cache entry, if this iterator is positioned on a
 	 *         non-tree.
 	 */
 	public DirCacheEntry getDirCacheEntry() {
 		return currentSubtree == null ? currentEntry : null;
 	}
 }
	/*
	* Copyright (C) 2008-2009, Google Inc.
	* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
	* and other copyright owners as documented in the project's IP log.
	*
	* This program and the accompanying materials are made available
	* under the terms of the Eclipse Distribution License v1.0 which
	* accompanies this distribution, is reproduced below, and is
	* available at http://www.eclipse.org/org/documents/edl-v10.php
	*
	* 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 Eclipse Foundation, Inc. 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.eclipse.jgit.dircache;

	import java.io.IOException;
	import java.util.Arrays;

	import org.eclipse.jgit.errors.IncorrectObjectTypeException;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.FileMode;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.treewalk.AbstractTreeIterator;
	import org.eclipse.jgit.treewalk.EmptyTreeIterator;

	/**
	* Iterate a {@link DirCache} as part of a <code>TreeWalk</code>.
	* <p>
	* This is an iterator to adapt a loaded <code>DirCache</code> instance (such as
	* read from an existing <code>.git/index</code> file) to the tree structure
	* used by a <code>TreeWalk</code>, making it possible for applications to walk
	* over any combination of tree objects already in the object database, index
	* files, or working directories.
	*
	* @see org.eclipse.jgit.treewalk.TreeWalk
	*/
	public class DirCacheIterator extends AbstractTreeIterator {
	/** The cache this iterator was created to walk. */
	protected final DirCache cache;

	/** The tree this iterator is walking. */
	private final DirCacheTree tree;

	/** First position in this tree. */
	private final int treeStart;

	/** Last position in this tree. */
	private final int treeEnd;

	/** Special buffer to hold the ObjectId of {@link #currentSubtree}. */
	private final byte[] subtreeId;

	/** Index of entry within {@link #cache}. */
	protected int ptr;

	/** Next subtree to consider within {@link #tree}. */
	private int nextSubtreePos;

	/** The current file entry from {@link #cache}. */
	protected DirCacheEntry currentEntry;

	/** The subtree containing {@link #currentEntry} if this is first entry. */
	protected DirCacheTree currentSubtree;

	/**
	* Create a new iterator for an already loaded DirCache instance.
	* <p>
	* The iterator implementation may copy part of the cache's data during
	* construction, so the cache must be read in prior to creating the
	* iterator.
	*
	* @param dc
	* the cache to walk. It must be already loaded into memory.
	*/
	public DirCacheIterator(final DirCache dc) {
	cache = dc;
	tree = dc.getCacheTree(true);
	treeStart = 0;
	treeEnd = tree.getEntrySpan();
	subtreeId = new byte[Constants.OBJECT_ID_LENGTH];
	if (!eof())
	parseEntry();
	}

	DirCacheIterator(final DirCacheIterator p, final DirCacheTree dct) {
	super(p, p.path, p.pathLen + 1);
	cache = p.cache;
	tree = dct;
	treeStart = p.ptr;
	treeEnd = treeStart + tree.getEntrySpan();
	subtreeId = p.subtreeId;
	ptr = p.ptr;
	parseEntry();
	}

	@Override
	public AbstractTreeIterator createSubtreeIterator(final Repository repo)
	throws IncorrectObjectTypeException, IOException {
	if (currentSubtree == null)
	throw new IncorrectObjectTypeException(getEntryObjectId(),
	Constants.TYPE_TREE);
	return new DirCacheIterator(this, currentSubtree);
	}

	@Override
	public EmptyTreeIterator createEmptyTreeIterator() {
	final byte[] n = new byte[Math.max(pathLen + 1, DEFAULT_PATH_SIZE)];
	System.arraycopy(path, 0, n, 0, pathLen);
	n[pathLen] = '/';
	return new EmptyTreeIterator(this, n, pathLen + 1);
	}

	@Override
	public byte[] idBuffer() {
	if (currentSubtree != null)
	return subtreeId;
	if (currentEntry != null)
	return currentEntry.idBuffer();
	return zeroid;
	}

	@Override
	public int idOffset() {
	if (currentSubtree != null)
	return 0;
	if (currentEntry != null)
	return currentEntry.idOffset();
	return 0;
	}

	@Override
	public boolean first() {
	return ptr == treeStart;
	}

	@Override
	public boolean eof() {
	return ptr == treeEnd;
	}

	@Override
	public void next(int delta) {
	while (--delta >= 0) {
	if (currentSubtree != null)
	ptr += currentSubtree.getEntrySpan();
	else
	ptr++;
	if (eof())
	break;
	parseEntry();
	}
	}

	@Override
	public void back(int delta) {
	while (--delta >= 0) {
	if (currentSubtree != null)
	nextSubtreePos--;
	ptr--;
	parseEntry();
	if (currentSubtree != null)
	ptr -= currentSubtree.getEntrySpan() - 1;
	}
	}

	private void parseEntry() {
	currentEntry = cache.getEntry(ptr);
	final byte[] cep = currentEntry.path;

	if (nextSubtreePos != tree.getChildCount()) {
	final DirCacheTree s = tree.getChild(nextSubtreePos);
	if (s.contains(cep, pathOffset, cep.length)) {
	// The current position is the first file of this subtree.
	// Use the subtree instead as the current position.
	//
	currentSubtree = s;
	nextSubtreePos++;

	if (s.isValid())
	s.getObjectId().copyRawTo(subtreeId, 0);
	else
	Arrays.fill(subtreeId, (byte) 0);
	mode = FileMode.TREE.getBits();
	path = cep;
	pathLen = pathOffset + s.nameLength();
	return;
	}
	}

	// The current position is a file/symlink/gitlink so we
	// do not have a subtree located here.
	//
	mode = currentEntry.getRawMode();
	path = cep;
	pathLen = cep.length;
	currentSubtree = null;
	}

	/**
	* Get the DirCacheEntry for the current file.
	*
	* @return the current cache entry, if this iterator is positioned on a
	* non-tree.
	*/
	public DirCacheEntry getDirCacheEntry() {
	return currentSubtree == null ? currentEntry : null;
	}
	}