src/main/java/net/pterodactylus/sone/core/SoneDownloader.java

   1 /*
   2  * Sone - SoneDownloader.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.IOException;
  21 import java.io.InputStream;
  22 import java.net.MalformedURLException;
  23 import java.util.HashSet;
  24 import java.util.Set;
  25 import java.util.logging.Level;
  26 import java.util.logging.Logger;
  27
  28 import net.pterodactylus.sone.core.Core.SoneStatus;
  29 import net.pterodactylus.sone.data.Post;
  30 import net.pterodactylus.sone.data.Profile;
  31 import net.pterodactylus.sone.data.Reply;
  32 import net.pterodactylus.sone.data.Sone;
  33 import net.pterodactylus.util.io.Closer;
  34 import net.pterodactylus.util.logging.Logging;
  35 import net.pterodactylus.util.service.AbstractService;
  36 import net.pterodactylus.util.xml.SimpleXML;
  37 import net.pterodactylus.util.xml.XML;
  38
  39 import org.w3c.dom.Document;
  40
  41 import freenet.client.FetchResult;
  42 import freenet.keys.FreenetURI;
  43 import freenet.support.api.Bucket;
  44
  45 /**
  46  * The Sone downloader is responsible for download Sones as they are updated.
  47  *
  48  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  49  */
  50 public class SoneDownloader extends AbstractService {
  51
  52         /** The logger. */
  53         private static final Logger logger = Logging.getLogger(SoneDownloader.class);
  54
  55         /** The core. */
  56         private final Core core;
  57
  58         /** The Freenet interface. */
  59         private final FreenetInterface freenetInterface;
  60
  61         /** The sones to update. */
  62         private final Set<Sone> sones = new HashSet<Sone>();
  63
  64         /**
  65          * Creates a new Sone downloader.
  66          *
  67          * @param core
  68          *            The core
  69          * @param freenetInterface
  70          *            The Freenet interface
  71          */
  72         public SoneDownloader(Core core, FreenetInterface freenetInterface) {
  73                 super("Sone Downloader", false);
  74                 this.core = core;
  75                 this.freenetInterface = freenetInterface;
  76         }
  77
  78         //
  79         // ACTIONS
  80         //
  81
  82         /**
  83          * Adds the given Sone to the set of Sones that will be watched for updates.
  84          *
  85          * @param sone
  86          *            The Sone to add
  87          */
  88         public void addSone(Sone sone) {
  89                 if (sones.add(sone)) {
  90                         freenetInterface.registerUsk(sone, this);
  91                 }
  92         }
  93
  94         /**
  95          * Removes the given Sone from the downloader.
  96          *
  97          * @param sone
  98          *            The Sone to stop watching
  99          */
 100         public void removeSone(Sone sone) {
 101                 if (sones.remove(sone)) {
 102                         freenetInterface.unregisterUsk(sone);
 103                 }
 104         }
 105
 106         /**
 107          * Fetches the updated Sone. This method is a callback method for
 108          * {@link FreenetInterface#registerUsk(Sone, SoneDownloader)}.
 109          *
 110          * @param sone
 111          *            The Sone to fetch
 112          */
 113         public void fetchSone(Sone sone) {
 114                 if (core.getSoneStatus(sone) == SoneStatus.downloading) {
 115                         return;
 116                 }
 117                 logger.log(Level.FINE, "Starting fetch for Sone “%s” from %s…", new Object[] { sone, sone.getRequestUri().setMetaString(new String[] { "sone.xml" }) });
 118                 FreenetURI requestUri = sone.getRequestUri().setMetaString(new String[] { "sone.xml" });
 119                 core.setSoneStatus(sone, SoneStatus.downloading);
 120                 try {
 121                         FetchResult fetchResult = freenetInterface.fetchUri(requestUri);
 122                         if (fetchResult == null) {
 123                                 /* TODO - mark Sone as bad. */
 124                                 return;
 125                         }
 126                         logger.log(Level.FINEST, "Got %d bytes back.", fetchResult.size());
 127                         Sone parsedSone = parseSone(sone, fetchResult, requestUri);
 128                         if (parsedSone != null) {
 129                                 core.addSone(parsedSone);
 130                         }
 131                 } finally {
 132                         core.setSoneStatus(sone, (sone.getTime() == 0) ? SoneStatus.unknown : SoneStatus.idle);
 133                 }
 134         }
 135
 136         /**
 137          * Parses a Sone from a fetch result.
 138          *
 139          * @param originalSone
 140          *            The sone to parse, or {@code null} if the Sone is yet unknown
 141          * @param fetchResult
 142          *            The fetch result
 143          * @param requestUri
 144          *            The requested URI
 145          * @return The parsed Sone, or {@code null} if the Sone could not be parsed
 146          */
 147         public Sone parseSone(Sone originalSone, FetchResult fetchResult, FreenetURI requestUri) {
 148                 logger.log(Level.FINEST, "Persing FetchResult (%d bytes, %s) for %s…", new Object[] { fetchResult.size(), fetchResult.getMimeType(), originalSone });
 149                 /* TODO - impose a size limit? */
 150                 InputStream xmlInputStream = null;
 151                 Bucket xmlBucket = null;
 152                 Sone sone;
 153                 try {
 154                         xmlBucket = fetchResult.asBucket();
 155                         xmlInputStream = xmlBucket.getInputStream();
 156                         Document document;
 157                         /* XML parsing is not thread-safe. */
 158                         synchronized (this) {
 159                                 document = XML.transformToDocument(xmlInputStream);
 160                         }
 161                         if (document == null) {
 162                                 /* TODO - mark Sone as bad. */
 163                                 logger.log(Level.WARNING, "Could not parse XML for Sone %s at %s!", new Object[] { originalSone, requestUri });
 164                                 return null;
 165                         }
 166                         SimpleXML soneXml;
 167                         try {
 168                                 soneXml = SimpleXML.fromDocument(document);
 169                         } catch (NullPointerException npe1) {
 170                                 /* for some reason, invalid XML can cause NPEs. */
 171                                 logger.log(Level.WARNING, "XML for Sone " + originalSone + " can not be parsed!", npe1);
 172                                 return null;
 173                         }
 174
 175                         /* check ID. */
 176                         String soneId = soneXml.getValue("id", null);
 177                         if ((originalSone != null) && !originalSone.getId().equals(soneId)) {
 178                                 /* TODO - mark Sone as bad. */
 179                                 logger.log(Level.WARNING, "Downloaded ID for Sone %s (%s) does not match known ID (%s)!", new Object[] { originalSone, originalSone.getId(), soneId });
 180                                 return null;
 181                         }
 182
 183                         /* load Sone from core. */
 184                         sone = originalSone;
 185                         if (sone == null) {
 186                                 sone = core.getSone(soneId).setRequestUri(requestUri.setMetaString(new String[] {}));
 187                         }
 188
 189                         String soneName = soneXml.getValue("name", null);
 190                         if (soneName == null) {
 191                                 /* TODO - mark Sone as bad. */
 192                                 logger.log(Level.WARNING, "Downloaded name for Sone %s was null!", new Object[] { sone });
 193                                 return null;
 194                         }
 195                         sone.setName(soneName);
 196
 197                         String soneTime = soneXml.getValue("time", null);
 198                         if (soneTime == null) {
 199                                 /* TODO - mark Sone as bad. */
 200                                 logger.log(Level.WARNING, "Downloaded time for Sone %s was null!", new Object[] { sone });
 201                                 return null;
 202                         }
 203                         try {
 204                                 sone.setTime(Long.parseLong(soneTime));
 205                         } catch (NumberFormatException nfe1) {
 206                                 /* TODO - mark Sone as bad. */
 207                                 logger.log(Level.WARNING, "Downloaded Sone %s with invalid time: %s", new Object[] { sone, soneTime });
 208                                 return null;
 209                         }
 210
 211                         SimpleXML profileXml = soneXml.getNode("profile");
 212                         if (profileXml == null) {
 213                                 /* TODO - mark Sone as bad. */
 214                                 logger.log(Level.WARNING, "Downloaded Sone %s has no profile!", new Object[] { sone });
 215                                 return null;
 216                         }
 217
 218                         /* parse profile. */
 219                         String profileFirstName = profileXml.getValue("first-name", null);
 220                         String profileMiddleName = profileXml.getValue("middle-name", null);
 221                         String profileLastName = profileXml.getValue("last-name", null);
 222                         Profile profile = new Profile().setFirstName(profileFirstName).setMiddleName(profileMiddleName).setLastName(profileLastName);
 223
 224                         /* parse posts. */
 225                         SimpleXML postsXml = soneXml.getNode("posts");
 226                         if (postsXml == null) {
 227                                 /* TODO - mark Sone as bad. */
 228                                 logger.log(Level.WARNING, "Downloaded Sone %s has no posts!", new Object[] { sone });
 229                                 return null;
 230                         }
 231
 232                         Set<Post> posts = new HashSet<Post>();
 233                         for (SimpleXML postXml : postsXml.getNodes("post")) {
 234                                 String postId = postXml.getValue("id", null);
 235                                 String postTime = postXml.getValue("time", null);
 236                                 String postText = postXml.getValue("text", null);
 237                                 if ((postId == null) || (postTime == null) || (postText == null)) {
 238                                         /* TODO - mark Sone as bad. */
 239                                         logger.log(Level.WARNING, "Downloaded post for Sone %s with missing data! ID: %s, Time: %s, Text: %s", new Object[] { sone, postId, postTime, postText });
 240                                         return null;
 241                                 }
 242                                 try {
 243                                         posts.add(core.getPost(postId).setSone(sone).setTime(Long.parseLong(postTime)).setText(postText));
 244                                 } catch (NumberFormatException nfe1) {
 245                                         /* TODO - mark Sone as bad. */
 246                                         logger.log(Level.WARNING, "Downloaded post for Sone %s with invalid time: %s", new Object[] { sone, postTime });
 247                                         return null;
 248                                 }
 249                         }
 250
 251                         /* parse replies. */
 252                         SimpleXML repliesXml = soneXml.getNode("replies");
 253                         if (repliesXml == null) {
 254                                 /* TODO - mark Sone as bad. */
 255                                 logger.log(Level.WARNING, "Downloaded Sone %s has no replies!", new Object[] { sone });
 256                                 return null;
 257                         }
 258
 259                         Set<Reply> replies = new HashSet<Reply>();
 260                         for (SimpleXML replyXml : repliesXml.getNodes("reply")) {
 261                                 String replyId = replyXml.getValue("id", null);
 262                                 String replyPostId = replyXml.getValue("post-id", null);
 263                                 String replyTime = replyXml.getValue("time", null);
 264                                 String replyText = replyXml.getValue("text", null);
 265                                 if ((replyId == null) || (replyPostId == null) || (replyTime == null) || (replyText == null)) {
 266                                         /* TODO - mark Sone as bad. */
 267                                         logger.log(Level.WARNING, "Downloaded reply for Sone %s with missing data! ID: %s, Post: %s, Time: %s, Text: %s", new Object[] { sone, replyId, replyPostId, replyTime, replyText });
 268                                         return null;
 269                                 }
 270                                 try {
 271                                         replies.add(core.getReply(replyId).setSone(sone).setPost(core.getPost(replyPostId)).setTime(Long.parseLong(replyTime)).setText(replyText));
 272                                 } catch (NumberFormatException nfe1) {
 273                                         /* TODO - mark Sone as bad. */
 274                                         logger.log(Level.WARNING, "Downloaded reply for Sone %s with invalid time: %s", new Object[] { sone, replyTime });
 275                                         return null;
 276                                 }
 277                         }
 278
 279                         /* parse liked post IDs. */
 280                         SimpleXML likePostIdsXml = soneXml.getNode("post-likes");
 281                         if (likePostIdsXml == null) {
 282                                 /* TODO - mark Sone as bad. */
 283                                 logger.log(Level.WARNING, "Downloaded Sone %s has no known Sones!", new Object[] { sone });
 284                                 return null;
 285                         }
 286
 287                         Set<String> likedPostIds = new HashSet<String>();
 288                         for (SimpleXML likedPostIdXml : likePostIdsXml.getNodes("post-like")) {
 289                                 String postId = likedPostIdXml.getValue();
 290                                 likedPostIds.add(postId);
 291                         }
 292
 293                         /* parse liked reply IDs. */
 294                         SimpleXML likeReplyIdsXml = soneXml.getNode("reply-likes");
 295                         if (likeReplyIdsXml == null) {
 296                                 /* TODO - mark Sone as bad. */
 297                                 logger.log(Level.WARNING, "Downloaded Sone %s has no reply likes!", new Object[] { sone });
 298                                 return null;
 299                         }
 300
 301                         Set<String> likedReplyIds = new HashSet<String>();
 302                         for (SimpleXML likedReplyIdXml : likeReplyIdsXml.getNodes("reply-like")) {
 303                                 String replyId = likedReplyIdXml.getValue();
 304                                 likedReplyIds.add(replyId);
 305                         }
 306
 307                         /* parse known Sones. */
 308                         SimpleXML knownSonesXml = soneXml.getNode("known-sones");
 309                         if (knownSonesXml == null) {
 310                                 /* TODO - mark Sone as bad. */
 311                                 logger.log(Level.WARNING, "Downloaded Sone %s has no known Sones!", new Object[] { sone });
 312                                 return null;
 313                         }
 314
 315                         Set<Sone> knownSones = new HashSet<Sone>();
 316                         for (SimpleXML knownSoneXml : knownSonesXml.getNodes("known-sone")) {
 317                                 String knownSoneId = knownSoneXml.getValue("sone-id", null);
 318                                 String knownSoneKey = knownSoneXml.getValue("sone-key", null);
 319                                 String knownSoneName = knownSoneXml.getValue("sone-name", null);
 320                                 if ((knownSoneId == null) || (knownSoneKey == null) || (knownSoneName == null)) {
 321                                         /* TODO - mark Sone as bad. */
 322                                         logger.log(Level.WARNING, "Downloaded known Sone for Sone %s with missing data! ID: %s, Key: %s, Name: %s", new Object[] { sone, knownSoneId, knownSoneKey, knownSoneName });
 323                                         return null;
 324                                 }
 325                                 try {
 326                                         knownSones.add(core.getSone(knownSoneId).setRequestUri(new FreenetURI(knownSoneKey)).setName(knownSoneName));
 327                                 } catch (MalformedURLException mue1) {
 328                                         /* TODO - mark Sone as bad. */
 329                                         logger.log(Level.WARNING, "Downloaded known Sone for Sone %s with invalid key: %s", new Object[] { sone, knownSoneKey });
 330                                         return null;
 331                                 }
 332                         }
 333
 334                         /* okay, apparently everything was parsed correctly. Now import. */
 335                         /* atomic setter operation on the Sone. */
 336                         synchronized (sone) {
 337                                 sone.setProfile(profile);
 338                                 sone.setPosts(posts);
 339                                 sone.setReplies(replies);
 340                                 sone.setLikePostIds(likedPostIds);
 341                                 sone.setModificationCounter(0);
 342                         }
 343
 344                         /* add all known Sones to core for downloading. */
 345                         for (Sone knownSone : knownSones) {
 346                                 core.addSone(knownSone);
 347                         }
 348
 349                 } catch (IOException ioe1) {
 350                         logger.log(Level.WARNING, "Could not read XML file from " + originalSone + "!", ioe1);
 351                         return null;
 352                 } finally {
 353                         if (xmlBucket != null) {
 354                                 xmlBucket.free();
 355                         }
 356                         Closer.close(xmlInputStream);
 357                 }
 358                 return sone;
 359         }
 360
 361         //
 362         // SERVICE METHODS
 363         //
 364
 365         /**
 366          * {@inheritDoc}
 367          */
 368         @Override
 369         protected void serviceStop() {
 370                 for (Sone sone : sones) {
 371                         freenetInterface.unregisterUsk(sone);
 372                 }
 373         }
 374
 375 }