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.dfs;
45
46 import java.io.IOException;
47 import java.util.ArrayList;
48 import java.util.Collections;
49 import java.util.List;
50
51 import org.eclipse.jgit.internal.storage.reftable.ReftableReader;
52
53 /**
54 * Tracks multiple open
55 * {@link org.eclipse.jgit.internal.storage.reftable.ReftableReader} instances.
56 */
57 public class DfsReftableStack implements AutoCloseable {
58 /**
59 * Opens a stack of tables for reading.
60 *
61 * @param ctx
62 * context to read the tables with. This {@code ctx} will be
63 * retained by the stack and each of the table readers.
64 * @param files
65 * the tables to open.
66 * @return stack reference to close the tables.
67 * @throws java.io.IOException
68 * a table could not be opened
69 */
70 public static DfsReftableStack open(DfsReader ctx, List<DfsReftable> files)
71 throws IOException {
72 DfsReftableStack stack = new DfsReftableStack(files.size());
73 boolean close = true;
74 try {
75 for (DfsReftable t : files) {
76 stack.files.add(t);
77 stack.tables.add(t.open(ctx));
78 }
79 close = false;
80 return stack;
81 } finally {
82 if (close) {
83 stack.close();
84 }
85 }
86 }
87
88 private final List<DfsReftable> files;
89 private final List<ReftableReader> tables;
90
91 private DfsReftableStack(int tableCnt) {
92 this.files = new ArrayList<>(tableCnt);
93 this.tables = new ArrayList<>(tableCnt);
94 }
95
96 /**
97 * Get unmodifiable list of DfsRefatble files
98 *
99 * @return unmodifiable list of DfsRefatble files, in the same order the
100 * files were passed to {@link #open(DfsReader, List)}.
101 */
102 public List<DfsReftable> files() {
103 return Collections.unmodifiableList(files);
104 }
105
106 /**
107 * Get unmodifiable list of tables
108 *
109 * @return unmodifiable list of tables, in the same order the files were
110 * passed to {@link #open(DfsReader, List)}.
111 */
112 public List<ReftableReader> readers() {
113 return Collections.unmodifiableList(tables);
114 }
115
116 /** {@inheritDoc} */
117 @Override
118 public void close() {
119 for (ReftableReader t : tables) {
120 try {
121 t.close();
122 } catch (IOException e) {
123 // Ignore close failures.
124 }
125 }
126 }
127 }