src/main/java/net/pterodactylus/sone/freenet/wot/WebOfTrustConnector.java

   1 /*
   2  * Sone - WebOfTrustConnector.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.freenet.wot;
  19
  20 import java.util.Collections;
  21 import java.util.HashMap;
  22 import java.util.HashSet;
  23 import java.util.Map;
  24 import java.util.Set;
  25 import java.util.logging.Level;
  26 import java.util.logging.Logger;
  27
  28 import net.pterodactylus.util.logging.Logging;
  29 import freenet.support.SimpleFieldSet;
  30 import freenet.support.api.Bucket;
  31
  32 /**
  33  * Connector for the Web of Trust plugin.
  34  *
  35  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  36  */
  37 public class WebOfTrustConnector implements ConnectorListener {
  38
  39         /** The logger. */
  40         private static final Logger logger = Logging.getLogger(WebOfTrustConnector.class);
  41
  42         /** The name of the WoT plugin. */
  43         private static final String WOT_PLUGIN_NAME = "plugins.WoT.WoT";
  44
  45         /** A random connection identifier. */
  46         private static final String PLUGIN_CONNECTION_IDENTIFIER = "Sone-WoT-Connector-" + Math.abs(Math.random());
  47
  48         /** The current replies that we wait for. */
  49         private final Map<String, Reply> replies = Collections.synchronizedMap(new HashMap<String, Reply>());
  50
  51         /** The plugin connector. */
  52         private final PluginConnector pluginConnector;
  53
  54         /**
  55          * Creates a new Web of Trust connector that uses the given plugin
  56          * connector.
  57          *
  58          * @param pluginConnector
  59          *            The plugin connector
  60          */
  61         public WebOfTrustConnector(PluginConnector pluginConnector) {
  62                 this.pluginConnector = pluginConnector;
  63                 pluginConnector.addConnectorListener(WOT_PLUGIN_NAME, PLUGIN_CONNECTION_IDENTIFIER, this);
  64         }
  65
  66         //
  67         // ACTIONS
  68         //
  69
  70         /**
  71          * Loads all own identities from the Web of Trust plugin.
  72          *
  73          * @return All own identity
  74          * @throws PluginException
  75          *             if the own identities can not be loaded
  76          */
  77         public Set<OwnIdentity> loadAllOwnIdentities() throws PluginException {
  78                 Reply reply = performRequest(SimpleFieldSetConstructor.create().put("Message", "GetOwnIdentities").get(), "OwnIdentities");
  79                 SimpleFieldSet fields = reply.getFields();
  80                 int ownIdentityCounter = -1;
  81                 Set<OwnIdentity> ownIdentities = new HashSet<OwnIdentity>();
  82                 while (true) {
  83                         String id = fields.get("Identity" + ++ownIdentityCounter);
  84                         if (id == null) {
  85                                 break;
  86                         }
  87                         String requestUri = fields.get("RequestURI" + ownIdentityCounter);
  88                         String insertUri = fields.get("InsertURI" + ownIdentityCounter);
  89                         String nickname = fields.get("Nickname" + ownIdentityCounter);
  90                         OwnIdentity ownIdentity = new OwnIdentity(id, nickname, requestUri, insertUri);
  91                         ownIdentity.setContexts(parseContexts("Contexts" + ownIdentityCounter + ".", fields));
  92                         ownIdentity.setProperties(parseProperties("Properties" + ownIdentityCounter + ".", fields));
  93                         ownIdentities.add(ownIdentity);
  94                 }
  95                 return ownIdentities;
  96         }
  97
  98         /**
  99          * Loads all identities that the given identities trusts with a score of
 100          * more than 0.
 101          *
 102          * @param ownIdentity
 103          *            The own identity
 104          * @return All trusted identities
 105          * @throws PluginException
 106          *             if an error occured talking to the Web of Trust plugin
 107          */
 108         public Set<Identity> loadTrustedIdentities(OwnIdentity ownIdentity) throws PluginException {
 109                 return loadTrustedIdentities(ownIdentity, null);
 110         }
 111
 112         /**
 113          * Loads all identities that the given identities trusts with a score of
 114          * more than 0 and the (optional) given context.
 115          *
 116          * @param ownIdentity
 117          *            The own identity
 118          * @param context
 119          *            The context to filter, or {@code null}
 120          * @return All trusted identities
 121          * @throws PluginException
 122          *             if an error occured talking to the Web of Trust plugin
 123          */
 124         public Set<Identity> loadTrustedIdentities(OwnIdentity ownIdentity, String context) throws PluginException {
 125                 Reply reply = performRequest(SimpleFieldSetConstructor.create().put("Message", "GetIdentitiesByScore").put("TreeOwner", ownIdentity.getId()).put("Selection", "+").put("Context", (context == null) ? "" : context).get(), "Identities");
 126                 SimpleFieldSet fields = reply.getFields();
 127                 Set<Identity> identities = new HashSet<Identity>();
 128                 int identityCounter = -1;
 129                 while (true) {
 130                         String id = fields.get("Identity" + ++identityCounter);
 131                         if (id == null) {
 132                                 break;
 133                         }
 134                         String nickname = fields.get("Nickname" + identityCounter);
 135                         String requestUri = fields.get("RequestURI" + identityCounter);
 136                         Identity identity = new Identity(id, nickname, requestUri);
 137                         identity.setContexts(parseContexts("Contexts" + identityCounter + ".", fields));
 138                         identity.setProperties(parseProperties("Properties" + identityCounter + ".", fields));
 139                         identities.add(identity);
 140                 }
 141                 return identities;
 142         }
 143
 144         /**
 145          * Adds the given context to the given identity.
 146          *
 147          * @param ownIdentity
 148          *            The identity to add the context to
 149          * @param context
 150          *            The context to add
 151          * @throws PluginException
 152          *             if an error occured talking to the Web of Trust plugin
 153          */
 154         public void addContext(OwnIdentity ownIdentity, String context) throws PluginException {
 155                 performRequest(SimpleFieldSetConstructor.create().put("Message", "AddContext").put("Identity", ownIdentity.getId()).put("Context", context).get(), "ContextAdded");
 156         }
 157
 158         /**
 159          * Removes the given context from the given identity.
 160          *
 161          * @param ownIdentity
 162          *            The identity to remove the context from
 163          * @param context
 164          *            The context to remove
 165          * @throws PluginException
 166          *             if an error occured talking to the Web of Trust plugin
 167          */
 168         public void removeContext(OwnIdentity ownIdentity, String context) throws PluginException {
 169                 performRequest(SimpleFieldSetConstructor.create().put("Message", "RemoveContext").put("Identity", ownIdentity.getId()).put("Context", context).get(), "ContextRemoved");
 170         }
 171
 172         /**
 173          * Returns the value of the property with the given name.
 174          *
 175          * @param identity
 176          *            The identity whose properties to check
 177          * @param name
 178          *            The name of the property to return
 179          * @return The value of the property, or {@code null} if there is no value
 180          * @throws PluginException
 181          *             if an error occured talking to the Web of Trust plugin
 182          */
 183         public String getProperty(Identity identity, String name) throws PluginException {
 184                 Reply reply = performRequest(SimpleFieldSetConstructor.create().put("Message", "GetProperty").put("Identity", identity.getId()).put("Property", name).get(), "PropertyValue");
 185                 return reply.getFields().get("Property");
 186         }
 187
 188         /**
 189          * Sets the property with the given name to the given value.
 190          *
 191          * @param ownIdentity
 192          *            The identity to set the property on
 193          * @param name
 194          *            The name of the property to set
 195          * @param value
 196          *            The value to set
 197          * @throws PluginException
 198          *             if an error occured talking to the Web of Trust plugin
 199          */
 200         public void setProperty(OwnIdentity ownIdentity, String name, String value) throws PluginException {
 201                 performRequest(SimpleFieldSetConstructor.create().put("Message", "SetProperty").put("Identity", ownIdentity.getId()).put("Property", name).put("Value", value).get(), "PropertyAdded");
 202         }
 203
 204         /**
 205          * Removes the property with the given name.
 206          *
 207          * @param ownIdentity
 208          *            The identity to remove the property from
 209          * @param name
 210          *            The name of the property to remove
 211          * @throws PluginException
 212          *             if an error occured talking to the Web of Trust plugin
 213          */
 214         public void removeProperty(OwnIdentity ownIdentity, String name) throws PluginException {
 215                 performRequest(SimpleFieldSetConstructor.create().put("Message", "RemoveProperty").put("Identity", ownIdentity.getId()).put("Property", name).get(), "PropertyRemoved");
 216         }
 217
 218         /**
 219          * Pings the Web of Trust plugin. If the plugin can not be reached, a
 220          * {@link PluginException} is thrown.
 221          *
 222          * @throws PluginException
 223          *             if the plugin is not loaded
 224          */
 225         public void ping() throws PluginException {
 226                 performRequest(SimpleFieldSetConstructor.create().put("Message", "Ping").get(), "Pong");
 227         }
 228
 229         //
 230         // PRIVATE ACTIONS
 231         //
 232
 233         /**
 234          * Parses the contexts from the given fields.
 235          *
 236          * @param prefix
 237          *            The prefix to use to access the contexts
 238          * @param fields
 239          *            The fields to parse the contexts from
 240          * @return The parsed contexts
 241          */
 242         private Set<String> parseContexts(String prefix, SimpleFieldSet fields) {
 243                 Set<String> contexts = new HashSet<String>();
 244                 int contextCounter = -1;
 245                 while (true) {
 246                         String context = fields.get(prefix + "Context" + ++contextCounter);
 247                         if (context == null) {
 248                                 break;
 249                         }
 250                         contexts.add(context);
 251                 }
 252                 return contexts;
 253         }
 254
 255         /**
 256          * Parses the properties from the given fields.
 257          *
 258          * @param prefix
 259          *            The prefix to use to access the properties
 260          * @param fields
 261          *            The fields to parse the properties from
 262          * @return The parsed properties
 263          */
 264         private Map<String, String> parseProperties(String prefix, SimpleFieldSet fields) {
 265                 Map<String, String> properties = new HashMap<String, String>();
 266                 int propertiesCounter = -1;
 267                 while (true) {
 268                         String propertyName = fields.get(prefix + "Property" + ++propertiesCounter + ".Name");
 269                         if (propertyName == null) {
 270                                 break;
 271                         }
 272                         String propertyValue = fields.get(prefix + "Property" + propertiesCounter + ".Value");
 273                         properties.put(propertyName, propertyValue);
 274                 }
 275                 return properties;
 276         }
 277
 278         /**
 279          * Sends a request containing the given fields and waits for the target
 280          * message.
 281          *
 282          * @param fields
 283          *            The fields of the message
 284          * @param targetMessages
 285          *            The messages of the reply to wait for
 286          * @return The reply message
 287          * @throws PluginException
 288          *             if the request could not be sent
 289          */
 290         private Reply performRequest(SimpleFieldSet fields, String... targetMessages) throws PluginException {
 291                 return performRequest(fields, null, targetMessages);
 292         }
 293
 294         /**
 295          * Sends a request containing the given fields and waits for the target
 296          * message.
 297          *
 298          * @param fields
 299          *            The fields of the message
 300          * @param data
 301          *            The payload of the message
 302          * @param targetMessages
 303          *            The messages of the reply to wait for
 304          * @return The reply message
 305          * @throws PluginException
 306          *             if the request could not be sent
 307          */
 308         private Reply performRequest(SimpleFieldSet fields, Bucket data, String... targetMessages) throws PluginException {
 309                 @SuppressWarnings("synthetic-access")
 310                 Reply reply = new Reply();
 311                 for (String targetMessage : targetMessages) {
 312                         replies.put(targetMessage, reply);
 313                 }
 314                 replies.put("Error", reply);
 315                 synchronized (reply) {
 316                         pluginConnector.sendRequest(WOT_PLUGIN_NAME, PLUGIN_CONNECTION_IDENTIFIER, fields, data);
 317                         try {
 318                                 long now = System.currentTimeMillis();
 319                                 while ((reply.getFields() == null) && ((System.currentTimeMillis() - now) < 60000)) {
 320                                         reply.wait(60000 - (System.currentTimeMillis() - now));
 321                                 }
 322                                 if (reply.getFields() == null) {
 323                                         for (String targetMessage : targetMessages) {
 324                                                 replies.remove(targetMessage);
 325                                         }
 326                                         replies.remove("Error");
 327                                         throw new PluginException("Timeout waiting for " + targetMessages[0] + "!");
 328                                 }
 329                         } catch (InterruptedException ie1) {
 330                                 logger.log(Level.WARNING, "Got interrupted while waiting for reply on " + targetMessages[0] + ".", ie1);
 331                         }
 332                 }
 333                 for (String targetMessage : targetMessages) {
 334                         replies.remove(targetMessage);
 335                 }
 336                 replies.remove("Error");
 337                 if ((reply.getFields() != null) && reply.getFields().get("Message").equals("Error")) {
 338                         throw new PluginException("Could not perform request for " + targetMessages[0]);
 339                 }
 340                 return reply;
 341         }
 342
 343         //
 344         // INTERFACE ConnectorListener
 345         //
 346
 347         /**
 348          * {@inheritDoc}
 349          */
 350         @Override
 351         public void receivedReply(PluginConnector pluginConnector, SimpleFieldSet fields, Bucket data) {
 352                 String messageName = fields.get("Message");
 353                 logger.log(Level.FINEST, "Received Reply from Plugin: " + messageName);
 354                 Reply reply = replies.remove(messageName);
 355                 if (reply == null) {
 356                         logger.log(Level.FINE, "Not waiting for a “%s” message.", messageName);
 357                         return;
 358                 }
 359                 synchronized (reply) {
 360                         reply.setFields(fields);
 361                         reply.setData(data);
 362                         reply.notify();
 363                 }
 364         }
 365
 366         /**
 367          * Container for the data of the reply from a plugin.
 368          *
 369          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 370          */
 371         private static class Reply {
 372
 373                 /** The fields of the reply. */
 374                 private SimpleFieldSet fields;
 375
 376                 /** The payload of the reply. */
 377                 private Bucket data;
 378
 379                 /**
 380                  * Returns the fields of the reply.
 381                  *
 382                  * @return The fields of the reply
 383                  */
 384                 public SimpleFieldSet getFields() {
 385                         return fields;
 386                 }
 387
 388                 /**
 389                  * Sets the fields of the reply.
 390                  *
 391                  * @param fields
 392                  *            The fields of the reply
 393                  */
 394                 public void setFields(SimpleFieldSet fields) {
 395                         this.fields = fields;
 396                 }
 397
 398                 /**
 399                  * Returns the payload of the reply.
 400                  *
 401                  * @return The payload of the reply (may be {@code null})
 402                  */
 403                 @SuppressWarnings("unused")
 404                 public Bucket getData() {
 405                         return data;
 406                 }
 407
 408                 /**
 409                  * Sets the payload of the reply.
 410                  *
 411                  * @param data
 412                  *            The payload of the reply (may be {@code null})
 413                  */
 414                 public void setData(Bucket data) {
 415                         this.data = data;
 416                 }
 417
 418         }
 419
 420         /**
 421          * Helper method to create {@link SimpleFieldSet}s with terser code.
 422          *
 423          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 424          */
 425         private static class SimpleFieldSetConstructor {
 426
 427                 /** The field set being created. */
 428                 private SimpleFieldSet simpleFieldSet;
 429
 430                 /**
 431                  * Creates a new simple field set constructor.
 432                  *
 433                  * @param shortLived
 434                  *            {@code true} if the resulting simple field set should be
 435                  *            short-lived, {@code false} otherwise
 436                  */
 437                 private SimpleFieldSetConstructor(boolean shortLived) {
 438                         simpleFieldSet = new SimpleFieldSet(shortLived);
 439                 }
 440
 441                 //
 442                 // ACCESSORS
 443                 //
 444
 445                 /**
 446                  * Returns the created simple field set.
 447                  *
 448                  * @return The created simple field set
 449                  */
 450                 public SimpleFieldSet get() {
 451                         return simpleFieldSet;
 452                 }
 453
 454                 /**
 455                  * Sets the field with the given name to the given value.
 456                  *
 457                  * @param name
 458                  *            The name of the fleld
 459                  * @param value
 460                  *            The value of the field
 461                  * @return This constructor (for method chaining)
 462                  */
 463                 public SimpleFieldSetConstructor put(String name, String value) {
 464                         simpleFieldSet.putOverwrite(name, value);
 465                         return this;
 466                 }
 467
 468                 //
 469                 // ACTIONS
 470                 //
 471
 472                 /**
 473                  * Creates a new simple field set constructor.
 474                  *
 475                  * @return The created simple field set constructor
 476                  */
 477                 public static SimpleFieldSetConstructor create() {
 478                         return create(true);
 479                 }
 480
 481                 /**
 482                  * Creates a new simple field set constructor.
 483                  *
 484                  * @param shortLived
 485                  *            {@code true} if the resulting simple field set should be
 486                  *            short-lived, {@code false} otherwise
 487                  * @return The created simple field set constructor
 488                  */
 489                 public static SimpleFieldSetConstructor create(boolean shortLived) {
 490                         SimpleFieldSetConstructor simpleFieldSetConstructor = new SimpleFieldSetConstructor(shortLived);
 491                         return simpleFieldSetConstructor;
 492                 }
 493
 494         }
 495
 496 }