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1
11 package org.eclipse.core.runtime.adaptor;
12
13 import java.io.File  ;
14 import java.io.IOException ;
15 import java.net.URL ;
16 import org.eclipse.osgi.service.datalocation.Location;
17
18
21 public class BasicLocation implements Location {
22 private static class MockLocker implements Locker {
23 public boolean lock() throws IOException {
24 return true;
26 }
27 public void release() {
28 }
30
31 }
32 private boolean isReadOnly;
33 private URL location = null;
34 private Location parent;
35 private URL defaultValue;
36 private String property;
37
38 private File lockFile;
40 private Locker locker;
41 public static final String PROP_OSGI_LOCKING = "osgi.locking"; private static String LOCK_FILENAME = ".metadata/.lock"; public static boolean DEBUG;
44
45 private static boolean isRunningWithNio() {
46 try {
47 Class.forName("java.nio.channels.FileLock"); } catch (ClassNotFoundException e) {
49 return false;
50 }
51 return true;
52 }
53
54 public static Locker createLocker(File lock, String lockMode) {
55 if (lockMode == null)
56 lockMode = System.getProperties().getProperty(PROP_OSGI_LOCKING);
57
58 if ("none".equals(lockMode)) return new MockLocker();
60
61 if ("java.io".equals(lockMode)) return new Locker_JavaIo(lock);
63
64 if ("java.nio".equals(lockMode)) { if (isRunningWithNio()) {
66 return new Locker_JavaNio(lock);
67 } else {
68 return new Locker_JavaIo(lock);
70 }
71 }
72
73 if (isRunningWithNio()) {
75 return new Locker_JavaNio(lock);
76 } else {
77 return new Locker_JavaIo(lock);
78 }
79 }
80
81 public BasicLocation(String property, URL defaultValue, boolean isReadOnly) {
82 super();
83 this.property = property;
84 this.defaultValue = defaultValue;
85 this.isReadOnly = isReadOnly;
86 }
87
88 public boolean allowsDefault() {
89 return defaultValue != null;
90 }
91
92 public URL getDefault() {
93 return defaultValue;
94 }
95
96 public Location getParentLocation() {
97 return parent;
98 }
99
100 public synchronized URL getURL() {
101 if (location == null && defaultValue != null)
102 setURL(defaultValue, false);
103 return location;
104 }
105
106 public synchronized boolean isSet() {
107 return location != null;
108 }
109
110 public boolean isReadOnly() {
111 return isReadOnly;
112 }
113
114 public synchronized boolean setURL(URL value, boolean lock) throws IllegalStateException {
115 if (location != null)
116 throw new IllegalStateException (EclipseAdaptorMsg.formatter.getString("ECLIPSE_CANNOT_CHANGE_LOCATION")); File file = null;
118 if (value.getProtocol().equalsIgnoreCase("file")) file = new File (value.getFile(), LOCK_FILENAME);
120 lock = lock && !isReadOnly;
121 if (lock) {
122 try {
123 if (!lock(file))
124 return false;
125 } catch (IOException e) {
126 return false;
127 }
128 }
129 lockFile = file;
130 location = LocationManager.buildURL(value.toExternalForm(), true);
131 if (property != null)
132 System.getProperties().put(property, location.toExternalForm());
133 return lock;
134 }
135
136 public synchronized void setParent(Location value) {
137 parent = value;
138 }
139
140 public synchronized boolean lock() throws IOException {
141 if (!isSet())
142 return false;
143 return lock(lockFile);
144 }
145
146 private boolean lock(File lock) throws IOException {
147 if (lock == null || isReadOnly)
148 return false;
149
150 File parentFile = new File (lock.getParent());
151 if (!parentFile.exists())
152 if (!parentFile.mkdirs())
153 return false;
154
155 setLocker(lock);
156 if (locker == null)
157 return true;
158 boolean locked = false;
159 try {
160 locked = locker.lock();
161 return locked;
162 } finally {
163 if (!locked)
164 locker = null;
165 }
166 }
167
168 private void setLocker(File lock) {
169 if (locker != null)
170 return;
171 String lockMode = System.getProperties().getProperty(PROP_OSGI_LOCKING);
172 locker = createLocker(lock, lockMode);
173 }
174
175 public synchronized void release() {
176 if (locker != null)
177 locker.release();
178 }
179 } |
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