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                                         throw new PluginException("Timeout waiting for " + targetMessages[0] + "!");
 324                                 }
 325                         } catch (InterruptedException ie1) {
 326                                 logger.log(Level.WARNING, "Got interrupted while waiting for reply on " + targetMessages[0] + ".", ie1);
 327                         }
 328                 }
 329                 for (String targetMessage : targetMessages) {
 330                         replies.remove(targetMessage);
 331                 }
 332                 replies.remove("Error");
 333                 if ((reply.getFields() != null) && reply.getFields().get("Message").equals("Error")) {
 334                         throw new PluginException("Could not perform request for " + targetMessages[0]);
 335                 }
 336                 return reply;
 337         }
 338
 339         //
 340         // INTERFACE ConnectorListener
 341         //
 342
 343         /**
 344          * {@inheritDoc}
 345          */
 346         @Override
 347         public void receivedReply(PluginConnector pluginConnector, SimpleFieldSet fields, Bucket data) {
 348                 String messageName = fields.get("Message");
 349                 logger.log(Level.FINEST, "Received Reply from Plugin: " + messageName);
 350                 Reply reply = replies.remove(messageName);
 351                 if (reply == null) {
 352                         logger.log(Level.FINE, "Not waiting for a “%s” message.", messageName);
 353                         return;
 354                 }
 355                 synchronized (reply) {
 356                         reply.setFields(fields);
 357                         reply.setData(data);
 358                         reply.notify();
 359                 }
 360         }
 361
 362         /**
 363          * Container for the data of the reply from a plugin.
 364          *
 365          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 366          */
 367         private static class Reply {
 368
 369                 /** The fields of the reply. */
 370                 private SimpleFieldSet fields;
 371
 372                 /** The payload of the reply. */
 373                 private Bucket data;
 374
 375                 /**
 376                  * Returns the fields of the reply.
 377                  *
 378                  * @return The fields of the reply
 379                  */
 380                 public SimpleFieldSet getFields() {
 381                         return fields;
 382                 }
 383
 384                 /**
 385                  * Sets the fields of the reply.
 386                  *
 387                  * @param fields
 388                  *            The fields of the reply
 389                  */
 390                 public void setFields(SimpleFieldSet fields) {
 391                         this.fields = fields;
 392                 }
 393
 394                 /**
 395                  * Returns the payload of the reply.
 396                  *
 397                  * @return The payload of the reply (may be {@code null})
 398                  */
 399                 @SuppressWarnings("unused")
 400                 public Bucket getData() {
 401                         return data;
 402                 }
 403
 404                 /**
 405                  * Sets the payload of the reply.
 406                  *
 407                  * @param data
 408                  *            The payload of the reply (may be {@code null})
 409                  */
 410                 public void setData(Bucket data) {
 411                         this.data = data;
 412                 }
 413
 414         }
 415
 416         /**
 417          * Helper method to create {@link SimpleFieldSet}s with terser code.
 418          *
 419          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 420          */
 421         private static class SimpleFieldSetConstructor {
 422
 423                 /** The field set being created. */
 424                 private SimpleFieldSet simpleFieldSet;
 425
 426                 /**
 427                  * Creates a new simple field set constructor.
 428                  *
 429                  * @param shortLived
 430                  *            {@code true} if the resulting simple field set should be
 431                  *            short-lived, {@code false} otherwise
 432                  */
 433                 private SimpleFieldSetConstructor(boolean shortLived) {
 434                         simpleFieldSet = new SimpleFieldSet(shortLived);
 435                 }
 436
 437                 //
 438                 // ACCESSORS
 439                 //
 440
 441                 /**
 442                  * Returns the created simple field set.
 443                  *
 444                  * @return The created simple field set
 445                  */
 446                 public SimpleFieldSet get() {
 447                         return simpleFieldSet;
 448                 }
 449
 450                 /**
 451                  * Sets the field with the given name to the given value.
 452                  *
 453                  * @param name
 454                  *            The name of the fleld
 455                  * @param value
 456                  *            The value of the field
 457                  * @return This constructor (for method chaining)
 458                  */
 459                 public SimpleFieldSetConstructor put(String name, String value) {
 460                         simpleFieldSet.putOverwrite(name, value);
 461                         return this;
 462                 }
 463
 464                 //
 465                 // ACTIONS
 466                 //
 467
 468                 /**
 469                  * Creates a new simple field set constructor.
 470                  *
 471                  * @return The created simple field set constructor
 472                  */
 473                 public static SimpleFieldSetConstructor create() {
 474                         return create(true);
 475                 }
 476
 477                 /**
 478                  * Creates a new simple field set constructor.
 479                  *
 480                  * @param shortLived
 481                  *            {@code true} if the resulting simple field set should be
 482                  *            short-lived, {@code false} otherwise
 483                  * @return The created simple field set constructor
 484                  */
 485                 public static SimpleFieldSetConstructor create(boolean shortLived) {
 486                         SimpleFieldSetConstructor simpleFieldSetConstructor = new SimpleFieldSetConstructor(shortLived);
 487                         return simpleFieldSetConstructor;
 488                 }
 489
 490         }
 491
 492 }