1 /*
2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.jrtfs;
27
28 import java.nio.file.DirectoryStream;
29 import java.nio.file.ClosedDirectoryStreamException;
30 import java.nio.file.DirectoryIteratorException;
31 import java.nio.file.NotDirectoryException;
32 import java.nio.file.Path;
33 import java.util.Iterator;
34 import java.util.NoSuchElementException;
35 import java.io.IOException;
36
37 final class JrtDirectoryStream implements DirectoryStream<Path> {
38 private final JrtFileSystem jrtfs;
39 private final byte[] path;
40 // prefix to be used for children of this directory
41 // so that child path are reported relatively (if needed)
42 private final String childPrefix;
43 private final DirectoryStream.Filter<? super Path> filter;
44 private volatile boolean isClosed;
45 private volatile Iterator<Path> itr;
46
47 JrtDirectoryStream(JrtPath jrtPath,
48 DirectoryStream.Filter<? super java.nio.file.Path> filter)
49 throws IOException
50 {
51 this.jrtfs = jrtPath.getFileSystem();
52 this.path = jrtPath.getResolvedPath();
53 // sanity check
54 if (!jrtfs.isDirectory(path, true))
55 throw new NotDirectoryException(jrtPath.toString());
56
57 // absolute path and does not have funky chars in front like /./java.base
58 if (jrtPath.isAbsolute() && (path.length == jrtPath.getPathLength())) {
59 childPrefix = null;
60 } else {
61 // cases where directory content needs to modified with prefix
62 // like ./java.base, /./java.base, java.base and so on.
63 String dirName = jrtPath.toString();
64 int idx = dirName.indexOf(JrtFileSystem.getString(path).substring(1));
65 childPrefix = dirName.substring(0, idx);
66 }
67 this.filter = filter;
68 }
69
70 @Override
71 public synchronized Iterator<Path> iterator() {
72 if (isClosed)
73 throw new ClosedDirectoryStreamException();
74 if (itr != null)
75 throw new IllegalStateException("Iterator has already been returned");
76
77 try {
78 itr = jrtfs.iteratorOf(path, childPrefix);
79 } catch (IOException e) {
80 throw new IllegalStateException(e);
81 }
82 return new Iterator<Path>() {
83 /*
84 * next Path value to return from this iterator.
85 * null value means hasNext() not called yet
86 * or last hasNext() returned false or resulted
87 * in exception. If last hasNext() returned true,
88 * then this field has non-null value.
89 */
90 private Path next;
91
92 // get-and-clear and set-next by these methods
93 private Path getAndClearNext() {
94 assert next != null;
95 Path result = this.next;
96 this.next = null;
97 return result;
98 }
99
100 private void setNext(Path path) {
101 assert path != null;
102 this.next = path;
103 }
104
105 // if hasNext() returns true, 'next' field has non-null Path
106 @Override
107 public synchronized boolean hasNext() {
108 if (next != null) {
109 return true;
110 }
111
112 if (isClosed) {
113 return false;
114 }
115
116 if (filter == null) {
117 if (itr.hasNext()) {
118 setNext(itr.next());
119 return true;
120 } else {
121 return false;
122 }
123 } else {
124 while (itr.hasNext()) {
125 Path tmpPath = itr.next();
126 try {
127 if (filter.accept(tmpPath)) {
128 setNext(tmpPath);
129 return true;
130 }
131 } catch (IOException ioe) {
132 throw new DirectoryIteratorException(ioe);
133 }
134 }
135
136 return false;
137 }
138 }
139
140 @Override
141 public synchronized Path next() {
142 if (next != null) {
143 return getAndClearNext();
144 }
145
146 if (isClosed) {
147 throw new NoSuchElementException();
148 }
149
150 if (next == null && itr.hasNext()) {
151 // missing hasNext() between next() calls.
152 if (hasNext()) {
153 return getAndClearNext();
154 }
155 }
156
157 throw new NoSuchElementException();
158 }
159
160 @Override
161 public void remove() {
162 throw new UnsupportedOperationException();
163 }
164 };
165 }
166
167 @Override
168 public synchronized void close() throws IOException {
169 isClosed = true;
170 }
171 }