Deduplicate functionality.
[Sone.git] / src / main / java / net / pterodactylus / sone / core / SoneInserter.java
1 /*
2  * FreenetSone - SoneInserter.java - Copyright © 2010 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 java.io.InputStreamReader;
21 import java.io.StringWriter;
22 import java.nio.charset.Charset;
23 import java.util.ArrayList;
24 import java.util.HashMap;
25 import java.util.HashSet;
26 import java.util.Map;
27 import java.util.logging.Level;
28 import java.util.logging.Logger;
29
30 import net.pterodactylus.sone.core.Core.SoneStatus;
31 import net.pterodactylus.sone.data.Post;
32 import net.pterodactylus.sone.data.Reply;
33 import net.pterodactylus.sone.data.Sone;
34 import net.pterodactylus.sone.freenet.StringBucket;
35 import net.pterodactylus.sone.main.SonePlugin;
36 import net.pterodactylus.util.io.Closer;
37 import net.pterodactylus.util.logging.Logging;
38 import net.pterodactylus.util.service.AbstractService;
39 import net.pterodactylus.util.template.DefaultTemplateFactory;
40 import net.pterodactylus.util.template.ReflectionAccessor;
41 import net.pterodactylus.util.template.Template;
42 import net.pterodactylus.util.template.TemplateException;
43 import net.pterodactylus.util.template.XmlFilter;
44 import freenet.client.async.ManifestElement;
45 import freenet.keys.FreenetURI;
46
47 /**
48  * A Sone inserter is responsible for inserting a Sone if it has changed.
49  *
50  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
51  */
52 public class SoneInserter extends AbstractService {
53
54         /** The logger. */
55         private static final Logger logger = Logging.getLogger(SoneInserter.class);
56
57         /** The insertion delay (in seconds). */
58         private static volatile int insertionDelay = 60;
59
60         /** The template factory used to create the templates. */
61         private static final DefaultTemplateFactory templateFactory = new DefaultTemplateFactory();
62
63         static {
64                 templateFactory.addAccessor(Object.class, new ReflectionAccessor());
65                 templateFactory.addFilter("xml", new XmlFilter());
66         }
67
68         /** The UTF-8 charset. */
69         private static final Charset utf8Charset = Charset.forName("UTF-8");
70
71         /** The core. */
72         private final Core core;
73
74         /** The Freenet interface. */
75         private final FreenetInterface freenetInterface;
76
77         /** The Sone to insert. */
78         private final Sone sone;
79
80         /** Whether a modification has been detected. */
81         private volatile boolean modified = false;
82
83         /** The fingerprint of the last insert. */
84         private volatile String lastInsertFingerprint;
85
86         /**
87          * Creates a new Sone inserter.
88          *
89          * @param core
90          *            The core
91          * @param freenetInterface
92          *            The freenet interface
93          * @param sone
94          *            The Sone to insert
95          */
96         public SoneInserter(Core core, FreenetInterface freenetInterface, Sone sone) {
97                 super("Sone Inserter for “" + sone.getName() + "”", false);
98                 this.core = core;
99                 this.freenetInterface = freenetInterface;
100                 this.sone = sone;
101         }
102
103         //
104         // ACCESSORS
105         //
106
107         /**
108          * Changes the insertion delay, i.e. the time the Sone inserter waits after
109          * it has noticed a Sone modification before it starts the insert.
110          *
111          * @param insertionDelay
112          *            The insertion delay (in seconds)
113          */
114         public static void setInsertionDelay(int insertionDelay) {
115                 SoneInserter.insertionDelay = insertionDelay;
116         }
117
118         /**
119          * Returns the fingerprint of the last insert.
120          *
121          * @return The fingerprint of the last insert
122          */
123         public String getLastInsertFingerprint() {
124                 return lastInsertFingerprint;
125         }
126
127         /**
128          * Sets the fingerprint of the last insert.
129          *
130          * @param lastInsertFingerprint
131          *            The fingerprint of the last insert
132          */
133         public void setLastInsertFingerprint(String lastInsertFingerprint) {
134                 this.lastInsertFingerprint = lastInsertFingerprint;
135         }
136
137         /**
138          * Returns whether the Sone inserter has detected a modification of the
139          * Sone.
140          *
141          * @return {@code true} if the Sone has been modified, {@code false}
142          *         otherwise
143          */
144         public boolean isModified() {
145                 return modified;
146         }
147
148         //
149         // SERVICE METHODS
150         //
151
152         /**
153          * {@inheritDoc}
154          */
155         @Override
156         protected void serviceRun() {
157                 long lastModificationTime = 0;
158                 String lastFingerprint = "";
159                 while (!shouldStop()) {
160                         /* check every seconds. */
161                         sleep(1000);
162
163                         /* don’t insert locked Sones. */
164                         if (core.isLocked(sone)) {
165                                 /* trigger redetection when the Sone is unlocked. */
166                                 synchronized (sone) {
167                                         modified = !sone.getFingerprint().equals(lastInsertFingerprint);
168                                 }
169                                 lastFingerprint = "";
170                                 lastModificationTime = 0;
171                                 continue;
172                         }
173
174                         InsertInformation insertInformation = null;
175                         synchronized (sone) {
176                                 String fingerprint = sone.getFingerprint();
177                                 if (!fingerprint.equals(lastFingerprint)) {
178                                         if (fingerprint.equals(lastInsertFingerprint)) {
179                                                 modified = false;
180                                                 lastModificationTime = 0;
181                                                 logger.log(Level.FINE, "Sone %s has been reverted to last insert state.", sone);
182                                         } else {
183                                                 lastModificationTime = System.currentTimeMillis();
184                                                 modified = true;
185                                                 sone.setTime(lastModificationTime);
186                                                 logger.log(Level.FINE, "Sone %s has been modified, waiting %d seconds before inserting.", new Object[] { sone.getName(), insertionDelay });
187                                         }
188                                         lastFingerprint = fingerprint;
189                                 }
190                                 if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
191                                         lastInsertFingerprint = fingerprint;
192                                         insertInformation = new InsertInformation(sone);
193                                 }
194                         }
195
196                         if (insertInformation != null) {
197                                 logger.log(Level.INFO, "Inserting Sone “%s”…", new Object[] { sone.getName() });
198
199                                 boolean success = false;
200                                 try {
201                                         core.setSoneStatus(sone, SoneStatus.inserting);
202                                         FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri().setKeyType("USK").setSuggestedEdition(0), insertInformation.generateManifestEntries(), "index.html");
203                                         /* at this point we might already be stopped. */
204                                         if (shouldStop()) {
205                                                 /* if so, bail out, don’t change anything. */
206                                                 break;
207                                         }
208                                         sone.setLatestEdition(finalUri.getEdition());
209                                         success = true;
210                                         logger.log(Level.INFO, "Inserted Sone “%s” at %s.", new Object[] { sone.getName(), finalUri });
211                                 } catch (SoneException se1) {
212                                         logger.log(Level.WARNING, "Could not insert Sone “" + sone.getName() + "”!", se1);
213                                 } finally {
214                                         core.setSoneStatus(sone, SoneStatus.idle);
215                                 }
216
217                                 /*
218                                  * reset modification counter if Sone has not been modified
219                                  * while it was inserted.
220                                  */
221                                 if (success) {
222                                         synchronized (sone) {
223                                                 if (lastInsertFingerprint.equals(sone.getFingerprint())) {
224                                                         logger.log(Level.FINE, "Sone “%s” was not modified further, resetting counter…", new Object[] { sone });
225                                                         core.saveSone(sone);
226                                                         lastModificationTime = 0;
227                                                         modified = false;
228                                                 }
229                                         }
230                                 }
231                         }
232                 }
233         }
234
235         /**
236          * Container for information that are required to insert a Sone. This
237          * container merely exists to copy all relevant data without holding a lock
238          * on the {@link Sone} object for too long.
239          *
240          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
241          */
242         private class InsertInformation {
243
244                 /** All properties of the Sone, copied for thread safety. */
245                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
246
247                 /**
248                  * Creates a new insert information container.
249                  *
250                  * @param sone
251                  *            The sone to insert
252                  */
253                 public InsertInformation(Sone sone) {
254                         soneProperties.put("id", sone.getId());
255                         soneProperties.put("name", sone.getName());
256                         soneProperties.put("time", sone.getTime());
257                         soneProperties.put("requestUri", sone.getRequestUri());
258                         soneProperties.put("insertUri", sone.getInsertUri());
259                         soneProperties.put("profile", sone.getProfile());
260                         soneProperties.put("posts", new ArrayList<Post>(sone.getPosts()));
261                         soneProperties.put("replies", new HashSet<Reply>(sone.getReplies()));
262                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
263                         soneProperties.put("likeReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
264                 }
265
266                 //
267                 // ACCESSORS
268                 //
269
270                 /**
271                  * Returns the insert URI of the Sone.
272                  *
273                  * @return The insert URI of the Sone
274                  */
275                 public FreenetURI getInsertUri() {
276                         return (FreenetURI) soneProperties.get("insertUri");
277                 }
278
279                 //
280                 // ACTIONS
281                 //
282
283                 /**
284                  * Generates all manifest entries required to insert this Sone.
285                  *
286                  * @return The manifest entries for the Sone insert
287                  */
288                 public HashMap<String, Object> generateManifestEntries() {
289                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
290
291                         /* first, create an index.html. */
292                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
293
294                         /* now, store the sone. */
295                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
296
297                         return manifestEntries;
298                 }
299
300                 //
301                 // PRIVATE METHODS
302                 //
303
304                 /**
305                  * Creates a new manifest element.
306                  *
307                  * @param name
308                  *            The name of the file
309                  * @param contentType
310                  *            The content type of the file
311                  * @param templateName
312                  *            The name of the template to render
313                  * @return The manifest element
314                  */
315                 @SuppressWarnings("synthetic-access")
316                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
317                         InputStreamReader templateInputStreamReader;
318                         Template template = templateFactory.createTemplate(templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset));
319                         try {
320                                 template.parse();
321                         } catch (TemplateException te1) {
322                                 logger.log(Level.SEVERE, "Could not parse template “" + templateName + "”!", te1);
323                                 return null;
324                         } finally {
325                                 Closer.close(templateInputStreamReader);
326                         }
327
328                         template.set("currentSone", soneProperties);
329                         template.set("version", SonePlugin.VERSION);
330                         StringWriter writer = new StringWriter();
331                         StringBucket bucket = null;
332                         try {
333                                 template.render(writer);
334                                 bucket = new StringBucket(writer.toString(), utf8Charset);
335                                 return new ManifestElement(name, bucket, contentType, bucket.size());
336                         } catch (TemplateException te1) {
337                                 logger.log(Level.SEVERE, "Could not render template “" + templateName + "”!", te1);
338                                 return null;
339                         } finally {
340                                 Closer.close(writer);
341                                 if (bucket != null) {
342                                         bucket.free();
343                                 }
344                         }
345                 }
346
347         }
348
349 }