Use a static import.
[Sone.git] / src / main / java / net / pterodactylus / sone / core / SoneInserter.java
1 /*
2  * Sone - SoneInserter.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.core;
19
20 import static com.google.common.base.Preconditions.checkArgument;
21 import static net.pterodactylus.sone.data.Album.NOT_EMPTY;
22 import static net.pterodactylus.sone.data.Sone.TO_FREENET_URI;
23
24 import java.io.InputStreamReader;
25 import java.io.StringWriter;
26 import java.nio.charset.Charset;
27 import java.util.HashMap;
28 import java.util.HashSet;
29 import java.util.Map;
30 import java.util.logging.Level;
31 import java.util.logging.Logger;
32
33 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
34 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
35 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
36 import net.pterodactylus.sone.data.Album;
37 import net.pterodactylus.sone.data.Post;
38 import net.pterodactylus.sone.data.Reply;
39 import net.pterodactylus.sone.data.Sone;
40 import net.pterodactylus.sone.data.Sone.SoneStatus;
41 import net.pterodactylus.sone.freenet.StringBucket;
42 import net.pterodactylus.sone.main.SonePlugin;
43 import net.pterodactylus.util.io.Closer;
44 import net.pterodactylus.util.logging.Logging;
45 import net.pterodactylus.util.service.AbstractService;
46 import net.pterodactylus.util.template.HtmlFilter;
47 import net.pterodactylus.util.template.ReflectionAccessor;
48 import net.pterodactylus.util.template.Template;
49 import net.pterodactylus.util.template.TemplateContext;
50 import net.pterodactylus.util.template.TemplateContextFactory;
51 import net.pterodactylus.util.template.TemplateException;
52 import net.pterodactylus.util.template.TemplateParser;
53 import net.pterodactylus.util.template.XmlFilter;
54
55 import freenet.client.async.ManifestElement;
56 import freenet.keys.FreenetURI;
57
58 import com.google.common.collect.FluentIterable;
59 import com.google.common.collect.Ordering;
60 import com.google.common.eventbus.EventBus;
61
62 /**
63  * A Sone inserter is responsible for inserting a Sone if it has changed.
64  *
65  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
66  */
67 public class SoneInserter extends AbstractService {
68
69         /** The logger. */
70         private static final Logger logger = Logging.getLogger(SoneInserter.class);
71
72         /** The insertion delay (in seconds). */
73         private static volatile int insertionDelay = 60;
74
75         /** The template factory used to create the templates. */
76         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
77
78         static {
79                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
80                 templateContextFactory.addFilter("xml", new XmlFilter());
81                 templateContextFactory.addFilter("html", new HtmlFilter());
82         }
83
84         /** The UTF-8 charset. */
85         private static final Charset utf8Charset = Charset.forName("UTF-8");
86
87         /** The core. */
88         private final Core core;
89
90         /** The event bus. */
91         private final EventBus eventBus;
92
93         /** The Freenet interface. */
94         private final FreenetInterface freenetInterface;
95
96         /** The Sone to insert. */
97         private volatile Sone sone;
98
99         /** Whether a modification has been detected. */
100         private volatile boolean modified = false;
101
102         /** The fingerprint of the last insert. */
103         private volatile String lastInsertFingerprint;
104
105         /**
106          * Creates a new Sone inserter.
107          *
108          * @param core
109          *            The core
110          * @param eventBus
111          *            The event bus
112          * @param freenetInterface
113          *            The freenet interface
114          * @param sone
115          *            The Sone to insert
116          */
117         public SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, Sone sone) {
118                 super("Sone Inserter for “" + sone.getName() + "”", false);
119                 this.core = core;
120                 this.eventBus = eventBus;
121                 this.freenetInterface = freenetInterface;
122                 this.sone = sone;
123         }
124
125         //
126         // ACCESSORS
127         //
128
129         /**
130          * Sets the Sone to insert.
131          *
132          * @param sone
133          *              The Sone to insert
134          * @return This Sone inserter
135          */
136         public SoneInserter setSone(Sone sone) {
137                 checkArgument((this.sone == null) || sone.equals(this.sone), "Sone to insert can not be set to a different Sone");
138                 this.sone = sone;
139                 return this;
140         }
141
142         /**
143          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
144          * has noticed a Sone modification before it starts the insert.
145          *
146          * @param insertionDelay
147          *            The insertion delay (in seconds)
148          */
149         public static void setInsertionDelay(int insertionDelay) {
150                 SoneInserter.insertionDelay = insertionDelay;
151         }
152
153         /**
154          * Returns the fingerprint of the last insert.
155          *
156          * @return The fingerprint of the last insert
157          */
158         public String getLastInsertFingerprint() {
159                 return lastInsertFingerprint;
160         }
161
162         /**
163          * Sets the fingerprint of the last insert.
164          *
165          * @param lastInsertFingerprint
166          *            The fingerprint of the last insert
167          */
168         public void setLastInsertFingerprint(String lastInsertFingerprint) {
169                 this.lastInsertFingerprint = lastInsertFingerprint;
170         }
171
172         /**
173          * Returns whether the Sone inserter has detected a modification of the
174          * Sone.
175          *
176          * @return {@code true} if the Sone has been modified, {@code false}
177          *         otherwise
178          */
179         public boolean isModified() {
180                 return modified;
181         }
182
183         //
184         // SERVICE METHODS
185         //
186
187         @Override
188         protected void serviceRun() {
189                 long lastModificationTime = 0;
190                 String lastInsertedFingerprint = lastInsertFingerprint;
191                 String lastFingerprint = "";
192                 Sone sone;
193                 while (!shouldStop()) {
194                         try {
195                                 /* check every seconds. */
196                                 sleep(1000);
197
198                                 /* don’t insert locked Sones. */
199                                 sone = this.sone;
200                                 if (core.isLocked(sone)) {
201                                         /* trigger redetection when the Sone is unlocked. */
202                                         synchronized (sone) {
203                                                 modified = !sone.getFingerprint().equals(lastInsertedFingerprint);
204                                         }
205                                         lastFingerprint = "";
206                                         lastModificationTime = 0;
207                                         continue;
208                                 }
209
210                                 InsertInformation insertInformation = null;
211                                 synchronized (sone) {
212                                         String fingerprint = sone.getFingerprint();
213                                         if (!fingerprint.equals(lastFingerprint)) {
214                                                 if (fingerprint.equals(lastInsertedFingerprint)) {
215                                                         modified = false;
216                                                         lastModificationTime = 0;
217                                                         logger.log(Level.FINE, String.format("Sone %s has been reverted to last insert state.", sone));
218                                                 } else {
219                                                         lastModificationTime = System.currentTimeMillis();
220                                                         modified = true;
221                                                         logger.log(Level.FINE, String.format("Sone %s has been modified, waiting %d seconds before inserting.", sone.getName(), insertionDelay));
222                                                 }
223                                                 lastFingerprint = fingerprint;
224                                         }
225                                         if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
226                                                 lastInsertedFingerprint = fingerprint;
227                                                 insertInformation = new InsertInformation(sone);
228                                         }
229                                 }
230
231                                 if (insertInformation != null) {
232                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
233
234                                         boolean success = false;
235                                         try {
236                                                 sone.setStatus(SoneStatus.inserting);
237                                                 long insertTime = System.currentTimeMillis();
238                                                 insertInformation.setTime(insertTime);
239                                                 eventBus.post(new SoneInsertingEvent(sone));
240                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
241                                                 eventBus.post(new SoneInsertedEvent(sone, System.currentTimeMillis() - insertTime));
242                                                 /* at this point we might already be stopped. */
243                                                 if (shouldStop()) {
244                                                         /* if so, bail out, don’t change anything. */
245                                                         break;
246                                                 }
247                                                 sone.setTime(insertTime);
248                                                 sone.modify().setLatestEdition(finalUri.getEdition()).update();
249                                                 core.touchConfiguration();
250                                                 success = true;
251                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
252                                         } catch (SoneException se1) {
253                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
254                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
255                                         } finally {
256                                                 sone.setStatus(SoneStatus.idle);
257                                         }
258
259                                         /*
260                                          * reset modification counter if Sone has not been modified
261                                          * while it was inserted.
262                                          */
263                                         if (success) {
264                                                 synchronized (sone) {
265                                                         if (lastInsertedFingerprint.equals(sone.getFingerprint())) {
266                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
267                                                                 lastModificationTime = 0;
268                                                                 lastInsertFingerprint = lastInsertedFingerprint;
269                                                                 core.touchConfiguration();
270                                                                 modified = false;
271                                                         }
272                                                 }
273                                         }
274                                 }
275                         } catch (Throwable t1) {
276                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
277                         }
278                 }
279         }
280
281         /**
282          * Container for information that are required to insert a Sone. This
283          * container merely exists to copy all relevant data without holding a lock
284          * on the {@link Sone} object for too long.
285          *
286          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
287          */
288         private class InsertInformation {
289
290                 /** All properties of the Sone, copied for thread safety. */
291                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
292
293                 /**
294                  * Creates a new insert information container.
295                  *
296                  * @param sone
297                  *            The sone to insert
298                  */
299                 public InsertInformation(Sone sone) {
300                         soneProperties.put("id", sone.getId());
301                         soneProperties.put("name", sone.getName());
302                         soneProperties.put("time", sone.getTime());
303                         soneProperties.put("requestUri", TO_FREENET_URI.apply(sone));
304                         soneProperties.put("profile", sone.getProfile());
305                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
306                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
307                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
308                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
309                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
310                 }
311
312                 //
313                 // ACCESSORS
314                 //
315
316                 /**
317                  * Returns the insert URI of the Sone.
318                  *
319                  * @return The insert URI of the Sone
320                  */
321                 public FreenetURI getInsertUri() {
322                         return (FreenetURI) soneProperties.get("insertUri");
323                 }
324
325                 /**
326                  * Sets the time of the Sone at the time of the insert.
327                  *
328                  * @param time
329                  *            The time of the Sone
330                  */
331                 public void setTime(long time) {
332                         soneProperties.put("time", time);
333                 }
334
335                 //
336                 // ACTIONS
337                 //
338
339                 /**
340                  * Generates all manifest entries required to insert this Sone.
341                  *
342                  * @return The manifest entries for the Sone insert
343                  */
344                 public HashMap<String, Object> generateManifestEntries() {
345                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
346
347                         /* first, create an index.html. */
348                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
349
350                         /* now, store the sone. */
351                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
352
353                         return manifestEntries;
354                 }
355
356                 //
357                 // PRIVATE METHODS
358                 //
359
360                 /**
361                  * Creates a new manifest element.
362                  *
363                  * @param name
364                  *            The name of the file
365                  * @param contentType
366                  *            The content type of the file
367                  * @param templateName
368                  *            The name of the template to render
369                  * @return The manifest element
370                  */
371                 @SuppressWarnings("synthetic-access")
372                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
373                         InputStreamReader templateInputStreamReader = null;
374                         Template template;
375                         try {
376                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
377                                 template = TemplateParser.parse(templateInputStreamReader);
378                         } catch (TemplateException te1) {
379                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
380                                 return null;
381                         } finally {
382                                 Closer.close(templateInputStreamReader);
383                         }
384
385                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
386                         templateContext.set("core", core);
387                         templateContext.set("currentSone", soneProperties);
388                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
389                         templateContext.set("version", SonePlugin.VERSION);
390                         StringWriter writer = new StringWriter();
391                         StringBucket bucket = null;
392                         try {
393                                 template.render(templateContext, writer);
394                                 bucket = new StringBucket(writer.toString(), utf8Charset);
395                                 return new ManifestElement(name, bucket, contentType, bucket.size());
396                         } catch (TemplateException te1) {
397                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
398                                 return null;
399                         } finally {
400                                 Closer.close(writer);
401                                 if (bucket != null) {
402                                         bucket.free();
403                                 }
404                         }
405                 }
406
407         }
408
409 }