1 /*
2 * Copyright (C) 2008-2009, Google Inc.
3 * Copyright (C) 2009, Robin Rosenberg <robin.rosenberg@dewire.com>
4 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
5 * and other copyright owners as documented in the project's IP log.
6 *
7 * This program and the accompanying materials are made available
8 * under the terms of the Eclipse Distribution License v1.0 which
9 * accompanies this distribution, is reproduced below, and is
10 * available at http://www.eclipse.org/org/documents/edl-v10.php
11 *
12 * All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or
15 * without modification, are permitted provided that the following
16 * conditions are met:
17 *
18 * - Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 *
21 * - Redistributions in binary form must reproduce the above
22 * copyright notice, this list of conditions and the following
23 * disclaimer in the documentation and/or other materials provided
24 * with the distribution.
25 *
26 * - Neither the name of the Eclipse Foundation, Inc. nor the
27 * names of its contributors may be used to endorse or promote
28 * products derived from this software without specific prior
29 * written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
32 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
33 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
34 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
36 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
37 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
38 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
39 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
40 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
43 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 */
45
46 package org.eclipse.jgit.dircache;
47
48 import java.io.IOException;
49
50 import org.eclipse.jgit.errors.CorruptObjectException;
51 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
52 import org.eclipse.jgit.lib.Constants;
53 import org.eclipse.jgit.lib.ObjectReader;
54 import org.eclipse.jgit.treewalk.AbstractTreeIterator;
55
56 /**
57 * Iterate and update a {@link org.eclipse.jgit.dircache.DirCache} as part of a
58 * <code>TreeWalk</code>.
59 * <p>
60 * Like {@link org.eclipse.jgit.dircache.DirCacheIterator} this iterator allows
61 * a DirCache to be used in parallel with other sorts of iterators in a
62 * TreeWalk. However any entry which appears in the source DirCache and which is
63 * skipped by the TreeFilter is automatically copied into
64 * {@link org.eclipse.jgit.dircache.DirCacheBuilder}, thus retaining it in the
65 * newly updated index.
66 * <p>
67 * This iterator is suitable for update processes, or even a simple delete
68 * algorithm. For example deleting a path:
69 *
70 * <pre>
71 * final DirCache dirc = db.lockDirCache();
72 * final DirCacheBuilder edit = dirc.builder();
73 *
74 * final TreeWalk walk = new TreeWalk(db);
75 * walk.reset();
76 * walk.setRecursive(true);
77 * walk.setFilter(PathFilter.create("name/to/remove"));
78 * walk.addTree(new DirCacheBuildIterator(edit));
79 *
80 * while (walk.next())
81 * ; // do nothing on a match as we want to remove matches
82 * edit.commit();
83 * </pre>
84 */
85 public class DirCacheBuildIterator extends DirCacheIterator {
86 private final DirCacheBuilder builder;
87
88 /**
89 * Create a new iterator for an already loaded DirCache instance.
90 * <p>
91 * The iterator implementation may copy part of the cache's data during
92 * construction, so the cache must be read in prior to creating the
93 * iterator.
94 *
95 * @param dcb
96 * the cache builder for the cache to walk. The cache must be
97 * already loaded into memory.
98 */
99 public DirCacheBuildIterator(DirCacheBuilder dcb) {
100 super(dcb.getDirCache());
101 builder = dcb;
102 }
103
104 DirCacheBuildIterator(final DirCacheBuildIterator p,
105 final DirCacheTree dct) {
106 super(p, dct);
107 builder = p.builder;
108 }
109
110 /** {@inheritDoc} */
111 @Override
112 public AbstractTreeIterator createSubtreeIterator(ObjectReader reader)
113 throws IncorrectObjectTypeException, IOException {
114 if (currentSubtree == null)
115 throw new IncorrectObjectTypeException(getEntryObjectId(),
116 Constants.TYPE_TREE);
117 return new DirCacheBuildIterator(this, currentSubtree);
118 }
119
120 /** {@inheritDoc} */
121 @Override
122 public void skip() throws CorruptObjectException {
123 if (currentSubtree != null)
124 builder.keep(ptr, currentSubtree.getEntrySpan());
125 else
126 builder.keep(ptr, 1);
127 next(1);
128 }
129
130 /** {@inheritDoc} */
131 @Override
132 public void stopWalk() {
133 final int cur = ptr;
134 final int cnt = cache.getEntryCount();
135 if (cur < cnt)
136 builder.keep(cur, cnt - cur);
137 }
138
139 /** {@inheritDoc} */
140 @Override
141 protected boolean needsStopWalk() {
142 return ptr < cache.getEntryCount();
143 }
144 }