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