1 /**
2 * This file Copyright (c) 2015-2018 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.resourceloader.file;
35
36 import static info.magnolia.resourceloader.ResourceOriginChange.Type.*;
37 import static info.magnolia.resourceloader.ResourceOriginChange.resourceChange;
38
39 import info.magnolia.dirwatch.WatcherCallback;
40 import info.magnolia.resourceloader.ResourceOriginChange;
41
42 import java.io.IOException;
43 import java.nio.file.FileVisitOption;
44 import java.nio.file.FileVisitResult;
45 import java.nio.file.Files;
46 import java.nio.file.Path;
47 import java.nio.file.SimpleFileVisitor;
48 import java.nio.file.attribute.BasicFileAttributes;
49 import java.util.Collections;
50
51 import org.slf4j.Logger;
52 import org.slf4j.LoggerFactory;
53
54 import com.google.common.base.Predicate;
55
56 /**
57 * A {@link WatcherCallback Watcher callback implementation} which dispatches the file system modification events to the {@link FileSystemResourceOrigin}.
58 */
59 class FileWatcherCallback implements WatcherCallback {
60
61 private static final Logger log = LoggerFactory.getLogger(FileWatcherCallback.class);
62
63 private final FileSystemResourceOrigin origin;
64 private final Predicate<Path> watchedPathFilter;
65
66 FileWatcherCallback(FileSystemResourceOrigin origin, Predicate<Path> watchedPathFilter) {
67 this.origin = origin;
68 this.watchedPathFilter = watchedPathFilter;
69 }
70
71 /**
72 * Contents of the added folders are recursively handled in the same fashion. This is done due to the fact
73 * that only a single event is generated by the file system when a file/folder is added.
74 *
75 * @see <a href="https://jira.magnolia-cms.com/browse/MAGNOLIA-6278">MAGNOLIA-6278</a>
76 */
77 @Override
78 public void added(Path path) {
79 dispatchResourceChange(path, ADDED, true);
80 }
81
82 /**
83 * Resource modifications are handled non-recursively since:
84 * - the case of a mere file is essentially non-recursive
85 * - most of the folder modification events are generated in addition to content structure modification (file/sub-directory removed/added).
86 * and => do not need additional care (even can be ignored)
87 */
88 @Override
89 public void modified(Path path) {
90 dispatchResourceChange(path, MODIFIED, false);
91 }
92
93 /**
94 * To be consistent with the logic of {@link #added(Path)} - contents of the removed folders have to be handled recursively as well.
95 * The bad thing is that by the time the folder deletion event is processed - its contents become non-resolvable
96 * and => cannot be easily traversed.
97 */
98 @Override
99 public void removed(Path path) {
100 dispatchResourceChange(path, REMOVED, false);
101 }
102
103 /**
104 * Communicate file system resource changes to the {@link FileSystemResource file system resource origin}.
105 *
106 * @param handleDirectoryContents indicates whether directory contents should be communicated (recursively) as well
107 */
108 private void dispatchResourceChange(Path changedResourcePath, ResourceOriginChange.Type type, boolean handleDirectoryContents) {
109 if (!watchedPathFilter.apply(changedResourcePath)) {
110 return;
111 }
112
113 final ResourceOriginChange.Builder resourceChange =
114 resourceChange().
115 ofType(type).
116 at(origin.parseResourcePath(changedResourcePath)).
117 inOrigin(origin);
118
119 origin.dispatchResourceChange(resourceChange.build());
120
121 if (handleDirectoryContents && Files.isDirectory(changedResourcePath)) {
122 try {
123 Files.walkFileTree(changedResourcePath, Collections.singleton(FileVisitOption.FOLLOW_LINKS), Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
124 @Override
125 public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
126 if (watchedPathFilter.apply(file)) {
127 origin.dispatchResourceChange(resourceChange.at(origin.parseResourcePath(file)).build());
128 }
129 return FileVisitResult.CONTINUE;
130 }
131
132 @Override
133 public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
134 if (!watchedPathFilter.apply(dir)) {
135 return FileVisitResult.SKIP_SUBTREE;
136 }
137 return FileVisitResult.CONTINUE;
138 }
139
140 @Override
141 public FileVisitResult visitFileFailed(Path file, IOException e) throws IOException {
142 log.warn("Visiting failed for {}", file);
143 return FileVisitResult.SKIP_SUBTREE;
144 }
145
146 });
147 } catch (IOException e) {
148 log.error("Failed to communicate file system resource changes recursively: {}", e.getMessage(), e);
149 }
150 }
151 }
152 }