1 | // License: GPL. For details, see LICENSE file.
|
---|
2 | package org.openstreetmap.josm.io;
|
---|
3 |
|
---|
4 | import java.io.File;
|
---|
5 | import java.io.IOException;
|
---|
6 | import java.nio.file.FileSystems;
|
---|
7 | import java.nio.file.Path;
|
---|
8 | import java.nio.file.StandardWatchEventKinds;
|
---|
9 | import java.nio.file.WatchEvent;
|
---|
10 | import java.nio.file.WatchEvent.Kind;
|
---|
11 | import java.nio.file.WatchKey;
|
---|
12 | import java.nio.file.WatchService;
|
---|
13 | import java.util.Collections;
|
---|
14 | import java.util.HashMap;
|
---|
15 | import java.util.Map;
|
---|
16 | import java.util.concurrent.Executors;
|
---|
17 |
|
---|
18 | import org.openstreetmap.josm.data.preferences.sources.SourceEntry;
|
---|
19 | import org.openstreetmap.josm.data.validation.OsmValidator;
|
---|
20 | import org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker;
|
---|
21 | import org.openstreetmap.josm.gui.mappaint.StyleSource;
|
---|
22 | import org.openstreetmap.josm.gui.mappaint.loader.MapPaintStyleLoader;
|
---|
23 | import org.openstreetmap.josm.gui.mappaint.mapcss.parsergen.ParseException;
|
---|
24 | import org.openstreetmap.josm.tools.CheckParameterUtil;
|
---|
25 | import org.openstreetmap.josm.tools.Logging;
|
---|
26 | import org.openstreetmap.josm.tools.Utils;
|
---|
27 |
|
---|
28 | /**
|
---|
29 | * Background thread that monitors certain files and perform relevant actions when they change.
|
---|
30 | * @since 7185
|
---|
31 | */
|
---|
32 | public class FileWatcher {
|
---|
33 |
|
---|
34 | private WatchService watcher;
|
---|
35 | private Thread thread;
|
---|
36 |
|
---|
37 | private final Map<Path, StyleSource> styleMap = new HashMap<>();
|
---|
38 | private final Map<Path, SourceEntry> ruleMap = new HashMap<>();
|
---|
39 |
|
---|
40 | /**
|
---|
41 | * Constructs a new {@code FileWatcher}.
|
---|
42 | */
|
---|
43 | public FileWatcher() {
|
---|
44 | try {
|
---|
45 | watcher = FileSystems.getDefault().newWatchService();
|
---|
46 | thread = new Thread((Runnable) this::processEvents, "File Watcher");
|
---|
47 | } catch (IOException e) {
|
---|
48 | Logging.error(e);
|
---|
49 | }
|
---|
50 | }
|
---|
51 |
|
---|
52 | /**
|
---|
53 | * Starts the File Watcher thread.
|
---|
54 | */
|
---|
55 | public final void start() {
|
---|
56 | if (thread != null && !thread.isAlive()) {
|
---|
57 | thread.start();
|
---|
58 | }
|
---|
59 | }
|
---|
60 |
|
---|
61 | /**
|
---|
62 | * Registers a map paint style for local file changes, allowing dynamic reloading.
|
---|
63 | * @param style The style to watch
|
---|
64 | * @throws IllegalArgumentException if {@code style} is null or if it does not provide a local file
|
---|
65 | * @throws IllegalStateException if the watcher service failed to start
|
---|
66 | * @throws IOException if an I/O error occurs
|
---|
67 | */
|
---|
68 | public void registerStyleSource(StyleSource style) throws IOException {
|
---|
69 | register(style, styleMap);
|
---|
70 | }
|
---|
71 |
|
---|
72 | /**
|
---|
73 | * Registers a validator rule for local file changes, allowing dynamic reloading.
|
---|
74 | * @param rule The rule to watch
|
---|
75 | * @throws IllegalArgumentException if {@code rule} is null or if it does not provide a local file
|
---|
76 | * @throws IllegalStateException if the watcher service failed to start
|
---|
77 | * @throws IOException if an I/O error occurs
|
---|
78 | * @since 7276
|
---|
79 | */
|
---|
80 | public void registerValidatorRule(SourceEntry rule) throws IOException {
|
---|
81 | register(rule, ruleMap);
|
---|
82 | }
|
---|
83 |
|
---|
84 | private <T extends SourceEntry> void register(T obj, Map<Path, T> map) throws IOException {
|
---|
85 | CheckParameterUtil.ensureParameterNotNull(obj, "obj");
|
---|
86 | if (watcher == null) {
|
---|
87 | throw new IllegalStateException("File watcher is not available");
|
---|
88 | }
|
---|
89 | // Get local file, as this method is only called for local style sources
|
---|
90 | File file = new File(obj.url);
|
---|
91 | // Get parent directory as WatchService allows only to monitor directories, not single files
|
---|
92 | File dir = file.getParentFile();
|
---|
93 | if (dir == null) {
|
---|
94 | throw new IllegalArgumentException("Resource "+obj+" does not have a parent directory");
|
---|
95 | }
|
---|
96 | synchronized (this) {
|
---|
97 | // Register directory. Can be called several times for a same directory without problem
|
---|
98 | // (it returns the same key so it should not send events several times)
|
---|
99 | dir.toPath().register(watcher, StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_CREATE);
|
---|
100 | map.put(file.toPath(), obj);
|
---|
101 | }
|
---|
102 | }
|
---|
103 |
|
---|
104 | /**
|
---|
105 | * Process all events for the key queued to the watcher.
|
---|
106 | */
|
---|
107 | private void processEvents() {
|
---|
108 | Logging.debug("File watcher thread started");
|
---|
109 | while (true) {
|
---|
110 |
|
---|
111 | // wait for key to be signaled
|
---|
112 | WatchKey key;
|
---|
113 | try {
|
---|
114 | key = watcher.take();
|
---|
115 | } catch (InterruptedException ex) {
|
---|
116 | Thread.currentThread().interrupt();
|
---|
117 | return;
|
---|
118 | }
|
---|
119 |
|
---|
120 | for (WatchEvent<?> event: key.pollEvents()) {
|
---|
121 | Kind<?> kind = event.kind();
|
---|
122 |
|
---|
123 | if (StandardWatchEventKinds.OVERFLOW.equals(kind)) {
|
---|
124 | continue;
|
---|
125 | }
|
---|
126 |
|
---|
127 | // The filename is the context of the event.
|
---|
128 | @SuppressWarnings("unchecked")
|
---|
129 | WatchEvent<Path> ev = (WatchEvent<Path>) event;
|
---|
130 | Path filename = ev.context();
|
---|
131 | if (filename == null) {
|
---|
132 | continue;
|
---|
133 | }
|
---|
134 |
|
---|
135 | // Only way to get full path (http://stackoverflow.com/a/7802029/2257172)
|
---|
136 | Path fullPath = ((Path) key.watchable()).resolve(filename);
|
---|
137 |
|
---|
138 | synchronized (this) {
|
---|
139 | StyleSource style = styleMap.get(fullPath);
|
---|
140 | SourceEntry rule = ruleMap.get(fullPath);
|
---|
141 | if (style != null) {
|
---|
142 | Logging.info("Map style "+style.getDisplayString()+" has been modified. Reloading style...");
|
---|
143 | Executors.newSingleThreadExecutor(Utils.newThreadFactory("mapstyle-reload-%d", Thread.NORM_PRIORITY)).submit(
|
---|
144 | new MapPaintStyleLoader(Collections.singleton(style)));
|
---|
145 | } else if (rule != null) {
|
---|
146 | Logging.info("Validator rule "+rule.getDisplayString()+" has been modified. Reloading rule...");
|
---|
147 | MapCSSTagChecker tagChecker = OsmValidator.getTest(MapCSSTagChecker.class);
|
---|
148 | if (tagChecker != null) {
|
---|
149 | try {
|
---|
150 | tagChecker.addMapCSS(rule.url);
|
---|
151 | } catch (IOException | ParseException e) {
|
---|
152 | Logging.warn(e);
|
---|
153 | }
|
---|
154 | }
|
---|
155 | } else if (Logging.isDebugEnabled()) {
|
---|
156 | Logging.debug("Received {0} event for unregistered file: {1}", kind.name(), fullPath);
|
---|
157 | }
|
---|
158 | }
|
---|
159 | }
|
---|
160 |
|
---|
161 | // Reset the key -- this step is critical to receive
|
---|
162 | // further watch events. If the key is no longer valid, the directory
|
---|
163 | // is inaccessible so exit the loop.
|
---|
164 | if (!key.reset()) {
|
---|
165 | break;
|
---|
166 | }
|
---|
167 | }
|
---|
168 | }
|
---|
169 | }
|
---|