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