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.internal.storage.file;
45
46 import static java.nio.charset.StandardCharsets.UTF_8;
47
48 import java.io.BufferedReader;
49 import java.io.File;
50 import java.io.FileInputStream;
51 import java.io.IOException;
52 import java.io.InputStreamReader;
53 import java.io.Reader;
54
55 import org.eclipse.jgit.lib.AnyObjectId;
56 import org.eclipse.jgit.lib.MutableObjectId;
57 import org.eclipse.jgit.lib.ObjectIdOwnerMap;
58 import org.eclipse.jgit.lib.ObjectIdSet;
59
60 /**
61 * Lazily loads a set of ObjectIds, one per line.
62 */
63 public class LazyObjectIdSetFile implements ObjectIdSet {
64 private final File src;
65 private ObjectIdOwnerMap<Entry> set;
66
67 /**
68 * Create a new lazy set from a file.
69 *
70 * @param src
71 * the source file.
72 */
73 public LazyObjectIdSetFile(File src) {
74 this.src = src;
75 }
76
77 /** {@inheritDoc} */
78 @Override
79 public boolean contains(AnyObjectId objectId) {
80 if (set == null) {
81 set = load();
82 }
83 return set.contains(objectId);
84 }
85
86 private ObjectIdOwnerMap<Entry> load() {
87 ObjectIdOwnerMap<Entry> r = new ObjectIdOwnerMap<>();
88 try (FileInputStream fin = new FileInputStream(src);
89 Reader rin = new InputStreamReader(fin, UTF_8);
90 BufferedReader br = new BufferedReader(rin)) {
91 MutableObjectId id = new MutableObjectId();
92 for (String line; (line = br.readLine()) != null;) {
93 id.fromString(line);
94 if (!r.contains(id)) {
95 r.add(new Entry(id));
96 }
97 }
98 } catch (IOException e) {
99 // Ignore IO errors accessing the lazy set.
100 }
101 return r;
102 }
103
104 static class Entry extends ObjectIdOwnerMap.Entry {
105 Entry(AnyObjectId id) {
106 super(id);
107 }
108 }
109 }