Declare variables closer to where they’re first used.
[Sone.git] / src / main / java / net / pterodactylus / sone / freenet / wot / IdentityManager.java
1 /*
2  * Sone - IdentityManager.java - Copyright © 2010–2013 David Roden
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 3 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 package net.pterodactylus.sone.freenet.wot;
19
20 import java.util.Collections;
21 import java.util.HashMap;
22 import java.util.HashSet;
23 import java.util.Map;
24 import java.util.Map.Entry;
25 import java.util.Set;
26 import java.util.logging.Level;
27 import java.util.logging.Logger;
28
29 import net.pterodactylus.sone.freenet.plugin.PluginException;
30 import net.pterodactylus.sone.freenet.wot.event.IdentityAddedEvent;
31 import net.pterodactylus.sone.freenet.wot.event.IdentityRemovedEvent;
32 import net.pterodactylus.sone.freenet.wot.event.IdentityUpdatedEvent;
33 import net.pterodactylus.sone.freenet.wot.event.OwnIdentityAddedEvent;
34 import net.pterodactylus.sone.freenet.wot.event.OwnIdentityRemovedEvent;
35 import net.pterodactylus.util.logging.Logging;
36 import net.pterodactylus.util.service.AbstractService;
37
38 import com.google.common.eventbus.EventBus;
39 import com.google.inject.Inject;
40 import com.google.inject.name.Named;
41
42 /**
43  * The identity manager takes care of loading and storing identities, their
44  * contexts, and properties. It does so in a way that does not expose errors via
45  * exceptions but it only logs them and tries to return sensible defaults.
46  * <p>
47  * It is also responsible for polling identities from the Web of Trust plugin
48  * and sending events to the {@link EventBus} when {@link Identity}s and
49  * {@link OwnIdentity}s are discovered or disappearing.
50  *
51  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
52  */
53 public class IdentityManager extends AbstractService {
54
55         /** Object used for synchronization. */
56         @SuppressWarnings("hiding")
57         private final Object syncObject = new Object() {
58                 /* inner class for better lock names. */
59         };
60
61         /** The logger. */
62         private static final Logger logger = Logging.getLogger(IdentityManager.class);
63
64         /** The event bus. */
65         private final EventBus eventBus;
66
67         /** The Web of Trust connector. */
68         private final WebOfTrustConnector webOfTrustConnector;
69
70         /** The context to filter for. */
71         private final String context;
72
73         /** The currently known own identities. */
74         /* synchronize access on syncObject. */
75         private final Map<String, OwnIdentity> currentOwnIdentities = new HashMap<String, OwnIdentity>();
76
77         /** The last time all identities were loaded. */
78         private volatile long identitiesLastLoaded;
79
80         /**
81          * Creates a new identity manager.
82          *
83          * @param eventBus
84          *            The event bus
85          * @param webOfTrustConnector
86          *            The Web of Trust connector
87          * @param context
88          *            The context to focus on (may be {@code null} to ignore
89          *            contexts)
90          */
91         @Inject
92         public IdentityManager(EventBus eventBus, WebOfTrustConnector webOfTrustConnector, @Named("WebOfTrustContext") String context) {
93                 super("Sone Identity Manager", false);
94                 this.eventBus = eventBus;
95                 this.webOfTrustConnector = webOfTrustConnector;
96                 this.context = context;
97         }
98
99         //
100         // ACCESSORS
101         //
102
103         /**
104          * Returns the last time all identities were loaded.
105          *
106          * @return The last time all identities were loaded (in milliseconds since
107          *         Jan 1, 1970 UTC)
108          */
109         public long getIdentitiesLastLoaded() {
110                 return identitiesLastLoaded;
111         }
112
113         /**
114          * Returns whether the Web of Trust plugin could be reached during the last
115          * try.
116          *
117          * @return {@code true} if the Web of Trust plugin is connected,
118          *         {@code false} otherwise
119          */
120         public boolean isConnected() {
121                 try {
122                         webOfTrustConnector.ping();
123                         return true;
124                 } catch (PluginException pe1) {
125                         /* not connected, ignore. */
126                         return false;
127                 }
128         }
129
130         /**
131          * Returns the own identity with the given ID.
132          *
133          * @param id
134          *            The ID of the own identity
135          * @return The own identity, or {@code null} if there is no such identity
136          */
137         public OwnIdentity getOwnIdentity(String id) {
138                 Set<OwnIdentity> allOwnIdentities = getAllOwnIdentities();
139                 for (OwnIdentity ownIdentity : allOwnIdentities) {
140                         if (ownIdentity.getId().equals(id)) {
141                                 return new DefaultOwnIdentity(ownIdentity);
142                         }
143                 }
144                 return null;
145         }
146
147         /**
148          * Returns all own identities.
149          *
150          * @return All own identities
151          */
152         public Set<OwnIdentity> getAllOwnIdentities() {
153                 return new HashSet<OwnIdentity>(currentOwnIdentities.values());
154         }
155
156         //
157         // SERVICE METHODS
158         //
159
160         /**
161          * {@inheritDoc}
162          */
163         @Override
164         protected void serviceRun() {
165                 Map<OwnIdentity, Map<String, Identity>> oldIdentities = Collections.emptyMap();
166                 while (!shouldStop()) {
167                         Map<OwnIdentity, Map<String, Identity>> currentIdentities = new HashMap<OwnIdentity, Map<String, Identity>>();
168                         Map<String, OwnIdentity> currentOwnIdentities = new HashMap<String, OwnIdentity>();
169
170                         boolean identitiesLoaded = false;
171                         try {
172                                 /* get all identities with the wanted context from WoT. */
173                                 logger.finer("Getting all Own Identities from WoT...");
174                                 Set<OwnIdentity> ownIdentities = webOfTrustConnector.loadAllOwnIdentities();
175                                 logger.finest(String.format("Loaded %d Own Identities.", ownIdentities.size()));
176
177                                 /* load trusted identities. */
178                                 for (OwnIdentity ownIdentity : ownIdentities) {
179                                         currentOwnIdentities.put(ownIdentity.getId(), ownIdentity);
180                                         Map<String, Identity> identities = new HashMap<String, Identity>();
181                                         currentIdentities.put(ownIdentity, identities);
182
183                                         /*
184                                          * if the context doesn’t match, skip getting trusted
185                                          * identities.
186                                          */
187                                         if ((context != null) && !ownIdentity.hasContext(context)) {
188                                                 continue;
189                                         }
190
191                                         /* load trusted identities. */
192                                         logger.finer(String.format("Getting trusted identities for %s...", ownIdentity.getId()));
193                                         Set<Identity> trustedIdentities = webOfTrustConnector.loadTrustedIdentities(ownIdentity, context);
194                                         logger.finest(String.format("Got %d trusted identities.", trustedIdentities.size()));
195                                         for (Identity identity : trustedIdentities) {
196                                                 identities.put(identity.getId(), identity);
197                                         }
198                                 }
199                                 identitiesLoaded = true;
200                                 identitiesLastLoaded = System.currentTimeMillis();
201                         } catch (WebOfTrustException wote1) {
202                                 logger.log(Level.WARNING, "WoT has disappeared!", wote1);
203                         }
204
205                         if (identitiesLoaded) {
206
207                                 /* check for changes. */
208                                 checkOwnIdentities(currentOwnIdentities);
209
210                                 /* now check for changes in remote identities. */
211                                 for (OwnIdentity ownIdentity : currentOwnIdentities.values()) {
212
213                                         /* find new identities. */
214                                         for (Identity currentIdentity : currentIdentities.get(ownIdentity).values()) {
215                                                 if (!oldIdentities.containsKey(ownIdentity) || !oldIdentities.get(ownIdentity).containsKey(currentIdentity.getId())) {
216                                                         logger.finest(String.format("Identity added for %s: %s", ownIdentity.getId(), currentIdentity));
217                                                         eventBus.post(new IdentityAddedEvent(ownIdentity, currentIdentity));
218                                                 }
219                                         }
220
221                                         /* find removed identities. */
222                                         if (oldIdentities.containsKey(ownIdentity)) {
223                                                 for (Identity oldIdentity : oldIdentities.get(ownIdentity).values()) {
224                                                         if (!currentIdentities.get(ownIdentity).containsKey(oldIdentity.getId())) {
225                                                                 logger.finest(String.format("Identity removed for %s: %s", ownIdentity.getId(), oldIdentity));
226                                                                 eventBus.post(new IdentityRemovedEvent(ownIdentity, oldIdentity));
227                                                         }
228                                                 }
229
230                                                 /* check for changes in the contexts. */
231                                                 for (Identity oldIdentity : oldIdentities.get(ownIdentity).values()) {
232                                                         if (!currentIdentities.get(ownIdentity).containsKey(oldIdentity.getId())) {
233                                                                 continue;
234                                                         }
235                                                         Identity newIdentity = currentIdentities.get(ownIdentity).get(oldIdentity.getId());
236                                                         Set<String> oldContexts = oldIdentity.getContexts();
237                                                         Set<String> newContexts = newIdentity.getContexts();
238                                                         if (oldContexts.size() != newContexts.size()) {
239                                                                 logger.finest(String.format("Contexts changed for %s: was: %s, is now: %s", ownIdentity.getId(), oldContexts, newContexts));
240                                                                 eventBus.post(new IdentityUpdatedEvent(ownIdentity, newIdentity));
241                                                                 continue;
242                                                         }
243                                                         for (String oldContext : oldContexts) {
244                                                                 if (!newContexts.contains(oldContext)) {
245                                                                         logger.finest(String.format("Context was removed for %s: %s", ownIdentity.getId(), oldContext));
246                                                                         eventBus.post(new IdentityUpdatedEvent(ownIdentity, newIdentity));
247                                                                         break;
248                                                                 }
249                                                         }
250                                                 }
251
252                                                 /* check for changes in the properties. */
253                                                 for (Identity oldIdentity : oldIdentities.get(ownIdentity).values()) {
254                                                         if (!currentIdentities.get(ownIdentity).containsKey(oldIdentity.getId())) {
255                                                                 continue;
256                                                         }
257                                                         Identity newIdentity = currentIdentities.get(ownIdentity).get(oldIdentity.getId());
258                                                         Map<String, String> oldProperties = oldIdentity.getProperties();
259                                                         Map<String, String> newProperties = newIdentity.getProperties();
260                                                         if (oldProperties.size() != newProperties.size()) {
261                                                                 logger.finest(String.format("Properties changed for %s: was: %s, is now: %s", ownIdentity.getId(), oldProperties, newProperties));
262                                                                 eventBus.post(new IdentityUpdatedEvent(ownIdentity, newIdentity));
263                                                                 continue;
264                                                         }
265                                                         for (Entry<String, String> oldProperty : oldProperties.entrySet()) {
266                                                                 if (!newProperties.containsKey(oldProperty.getKey()) || !newProperties.get(oldProperty.getKey()).equals(oldProperty.getValue())) {
267                                                                         logger.finest(String.format("Property was removed for %s: %s", ownIdentity.getId(), oldProperty));
268                                                                         eventBus.post(new IdentityUpdatedEvent(ownIdentity, newIdentity));
269                                                                         break;
270                                                                 }
271                                                         }
272                                                 }
273                                         }
274                                 }
275
276                                 /* remember the current set of identities. */
277                                 oldIdentities = currentIdentities;
278                         }
279
280                         /* wait a minute before checking again. */
281                         sleep(60 * 1000);
282                 }
283         }
284
285         //
286         // PRIVATE METHODS
287         //
288
289         /**
290          * Checks the given new list of own identities for added or removed own
291          * identities, as compared to {@link #currentOwnIdentities}.
292          *
293          * @param newOwnIdentities
294          *            The new own identities
295          */
296         private void checkOwnIdentities(Map<String, OwnIdentity> newOwnIdentities) {
297                 synchronized (syncObject) {
298
299                         /* find removed own identities: */
300                         for (OwnIdentity oldOwnIdentity : currentOwnIdentities.values()) {
301                                 OwnIdentity newOwnIdentity = newOwnIdentities.get(oldOwnIdentity.getId());
302                                 if ((newOwnIdentity == null) || ((context != null) && oldOwnIdentity.hasContext(context) && !newOwnIdentity.hasContext(context))) {
303                                         logger.finest(String.format("Own Identity removed: %s", oldOwnIdentity));
304                                         eventBus.post(new OwnIdentityRemovedEvent(new DefaultOwnIdentity(oldOwnIdentity)));
305                                 }
306                         }
307
308                         /* find added own identities. */
309                         for (OwnIdentity currentOwnIdentity : newOwnIdentities.values()) {
310                                 OwnIdentity oldOwnIdentity = currentOwnIdentities.get(currentOwnIdentity.getId());
311                                 if (((oldOwnIdentity == null) && ((context == null) || currentOwnIdentity.hasContext(context))) || ((oldOwnIdentity != null) && (context != null) && (!oldOwnIdentity.hasContext(context) && currentOwnIdentity.hasContext(context)))) {
312                                         logger.finest(String.format("Own Identity added: %s", currentOwnIdentity));
313                                         eventBus.post(new OwnIdentityAddedEvent(new DefaultOwnIdentity(currentOwnIdentity)));
314                                 }
315                         }
316
317                         currentOwnIdentities.clear();
318                         currentOwnIdentities.putAll(newOwnIdentities);
319                 }
320         }
321
322 }