1 /**
2 * Copyright (C) 2015, Google Inc.
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43
44 package org.eclipse.jgit.revwalk.filter;
45
46 import java.io.IOException;
47
48 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
49 import org.eclipse.jgit.errors.MissingObjectException;
50 import org.eclipse.jgit.lib.AnyObjectId;
51 import org.eclipse.jgit.revwalk.ObjectWalk;
52
53 /**
54 * Selects interesting objects when walking.
55 * <p>
56 * Applications should install the filter on an ObjectWalk by
57 * {@link org.eclipse.jgit.revwalk.ObjectWalk#setObjectFilter(ObjectFilter)}
58 * prior to starting traversal.
59 *
60 * @since 4.0
61 */
62 public abstract class ObjectFilter {
63 /** Default filter that always returns true. */
64 public static final ObjectFilter ALL = new AllFilter();
65
66 private static final class AllFilter extends ObjectFilter {
67 @Override
68 public boolean include(ObjectWalk walker, AnyObjectId o) {
69 return true;
70 }
71 }
72
73 /**
74 * Determine if the named object should be included in the walk.
75 *
76 * @param walker
77 * the active walker this filter is being invoked from within.
78 * @param objid
79 * the object currently being tested.
80 * @return {@code true} if the named object should be included in the walk.
81 * @throws org.eclipse.jgit.errors.MissingObjectException
82 * an object the filter needed to consult to determine its
83 * answer was missing
84 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
85 * an object the filter needed to consult to determine its
86 * answer was of the wrong type
87 * @throws java.io.IOException
88 * an object the filter needed to consult to determine its
89 * answer could not be read.
90 */
91 public abstract boolean include(ObjectWalk walker, AnyObjectId objid)
92 throws MissingObjectException, IncorrectObjectTypeException,
93 IOException;
94 }