1 /*
2 * Copyright (C) 2017, 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.internal.storage.reftable;
45
46 import java.io.IOException;
47
48 import org.eclipse.jgit.lib.Ref;
49
50 /**
51 * Iterator over references inside a
52 * {@link org.eclipse.jgit.internal.storage.reftable.Reftable}.
53 */
54 public abstract class RefCursor implements AutoCloseable {
55 /**
56 * Check if another reference is available.
57 *
58 * @return {@code true} if there is another result.
59 * @throws java.io.IOException
60 * references cannot be read.
61 */
62 public abstract boolean next() throws IOException;
63
64 /**
65 * Get reference at the current position.
66 *
67 * @return reference at the current position.
68 */
69 public abstract Ref getRef();
70
71 /**
72 * Whether the current reference was deleted.
73 *
74 * @return {@code true} if the current reference was deleted.
75 */
76 public boolean wasDeleted() {
77 Ref r = getRef();
78 return r.getStorage() == Ref.Storage.NEW && r.getObjectId() == null;
79 }
80
81 /** {@inheritDoc} */
82 @Override
83 public abstract void close();
84 }