1 /**
2 * This file Copyright (c) 2014-2015 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.classpathwatch;
35
36 import info.magnolia.init.MagnoliaConfigurationProperties;
37
38 import java.io.IOException;
39 import java.net.URL;
40 import java.util.concurrent.Executors;
41 import java.util.concurrent.Future;
42 import java.util.concurrent.ScheduledExecutorService;
43 import java.util.concurrent.TimeUnit;
44
45 import javax.inject.Inject;
46 import javax.inject.Singleton;
47
48 import org.slf4j.Logger;
49 import org.slf4j.LoggerFactory;
50
51 import com.google.common.base.Function;
52 import com.google.common.base.Predicate;
53
54 /**
55 * Service controlling execution of the @link {@link ClasspathScanner}.
56 */
57 @Singleton
58 public class ClasspathScannerService {
59
60 private static final int SCAN_INTERVAL = 10;
61
62 private static final Logger log = LoggerFactory.getLogger(ClasspathScannerService.class);
63
64 private final boolean devMode;
65 private ScheduledExecutorService executorService;
66 private ClasspathScanner scanner;
67
68 private Future<?> scannerFuture;
69
70 @Inject
71 public ClasspathScannerService(MagnoliaConfigurationProperties mcp) throws IOException {
72 this.devMode = mcp.getBooleanProperty("magnolia.develop");
73 if (!devMode) {
74 log.info("Not in dev mode, will not watch resource changes on the classpath.");
75 }
76 }
77
78 public void start() {
79 }
80
81 public boolean isEnabled() {
82 return devMode;
83 }
84
85 /**
86 * Sets up observation of classpath resource changes.
87 */
88 public synchronized void watch(Predicate<String> resourcesFilter, Predicate<? super URL> urlsFilter, Function<String, Void> callbackFunction) {
89 if (!devMode) {
90 return;
91 }
92
93 /*
94 * All ClasspathOrigins have the same resource and url exclusion filters, by implementation/design.
95 *
96 * - For now, first ClasspathResourceOrigin requesting #watchForChanges passes these on; scanner is then created accordingly.
97 * - Hence we currently don't support scanning for heterogeneous ClasspathOrigins with different filtering impl.
98 * - LegacyClasspathResourceOrigin is intentionally left out, in particular as it's not meant to host config files.
99 * - We may revise this whenever there is need for generalization.
100 */
101 if (scannerFuture == null) {
102 scanner = new ClasspathScanner(resourcesFilter, urlsFilter);
103
104 // We intentionally use a single thread executor (single ClasspathScanner with multiple callbacks)
105 executorService = Executors.newSingleThreadScheduledExecutor();
106 log.info("Scheduling execution of ClasspathScanner every {}s.", SCAN_INTERVAL);
107 scannerFuture = executorService.scheduleWithFixedDelay(scanner, SCAN_INTERVAL, SCAN_INTERVAL, TimeUnit.SECONDS);
108 }
109 scanner.watchResourceChanges(callbackFunction);
110 }
111
112 public void stop() {
113 if (executorService != null) {
114 executorService.shutdownNow();
115 boolean terminated = false;
116 try {
117 terminated = executorService.awaitTermination(1, TimeUnit.SECONDS);
118 } catch (InterruptedException e) {
119 log.error("Exception during service termination", e);
120 }
121 if (terminated) {
122 log.info("{} terminated.", getClass().getSimpleName());
123 } else {
124 log.warn("{} not terminated, some tasks are still running.", getClass().getSimpleName());
125 }
126 }
127 }
128
129 }