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