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