application/hub/main/database/wrapper/node/class_NodeDistributedHashTableDatabaseWrapper.php

   1 <?php
   2 /**
   3  * A database wrapper for distributed hash tables
   4  *
   5  * @author              Roland Haeder <webmaster@shipsimu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 Hub Developer Team
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.shipsimu.org
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  23  */
  24 class NodeDistributedHashTableDatabaseWrapper extends BaseDatabaseWrapper implements NodeDhtWrapper, Registerable {
  25         /**
  26          * "Cached" results for dabase for looking for unpublished entries
  27          */
  28         private $unpublishedEntriesInstance = NULL;
  29
  30         // Constants for database table names
  31         const DB_TABLE_NODE_DHT = 'node_dht';
  32
  33         // Constants for database column names
  34         const DB_COLUMN_NODE_ID            = 'node_id';
  35         const DB_COLUMN_SESSION_ID         = 'session_id';
  36         const DB_COLUMN_EXTERNAL_IP        = 'external_ip';
  37         const DB_COLUMN_LISTEN_PORT        = 'listen_port';
  38         const DB_COLUMN_PRIVATE_KEY_HASH   = 'private_key_hash';
  39         const DB_COLUMN_NODE_MODE          = 'node_mode';
  40         const DB_COLUMN_ACCEPTED_OBJECTS   = 'accepted_object_types';
  41         const DB_COLUMN_NODE_LIST          = 'node_list';
  42         const DB_COLUMN_PUBLICATION_STATUS = 'publication_status';
  43         const DB_COLUMN_ANSWER_STATUS      = 'answer_status';
  44
  45         // Publication status'
  46         const PUBLICATION_STATUS_PENDING = 'PENDING';
  47
  48         // Exception codes
  49         const EXCEPTION_NODE_ALREADY_REGISTERED = 0x800;
  50         const EXCEPTION_NODE_NOT_REGISTERED     = 0x801;
  51
  52         /**
  53          * Protected constructor
  54          *
  55          * @return      void
  56          */
  57         protected function __construct () {
  58                 // Call parent constructor
  59                 parent::__construct(__CLASS__);
  60         }
  61
  62         /**
  63          * Creates an instance of this database wrapper by a provided user class
  64          *
  65          * @return      $wrapperInstance        An instance of the created wrapper class
  66          */
  67         public static final function createNodeDistributedHashTableDatabaseWrapper () {
  68                 // Get a new instance
  69                 $wrapperInstance = new NodeDistributedHashTableDatabaseWrapper();
  70
  71                 // Set (primary!) table name
  72                 $wrapperInstance->setTableName(self::DB_TABLE_NODE_DHT);
  73
  74                 // Return the instance
  75                 return $wrapperInstance;
  76         }
  77
  78         /**
  79          * Static getter for an array of all DHT database entries
  80          *
  81          * @return      $elements       All elements for the DHT dabase
  82          */
  83         public static final function getAllElements () {
  84                 // Create array and ...
  85                 $elements = array(
  86                         self::DB_COLUMN_NODE_ID,
  87                         self::DB_COLUMN_SESSION_ID,
  88                         self::DB_COLUMN_EXTERNAL_IP,
  89                         self::DB_COLUMN_LISTEN_PORT,
  90                         self::DB_COLUMN_PRIVATE_KEY_HASH,
  91                         self::DB_COLUMN_NODE_MODE,
  92                         self::DB_COLUMN_ACCEPTED_OBJECTS,
  93                         self::DB_COLUMN_NODE_LIST
  94                 );
  95
  96                 // ... return it
  97                 return $elements;
  98         }
  99
 100         /**
 101          * Prepares a search instance for given node data
 102          *
 103          * @param       $nodeData                       An array with valid node data
 104          * @return      $searchInstance         An instance of a SearchCriteria class
 105          */
 106         private function prepareSearchInstance (array $nodeData) {
 107                 // Assert on array elements
 108                 assert(isset($nodeData[self::DB_COLUMN_NODE_ID]));
 109
 110                 // Get instance
 111                 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
 112
 113                 // Search for node id and limit it to one entry
 114                 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeData[self::DB_COLUMN_NODE_ID]);
 115                 $searchInstance->setLimit(1);
 116
 117                 // Return it
 118                 return $searchInstance;
 119         }
 120
 121         /**
 122          * Getter for result instance for unpublished entries
 123          *
 124          * @return      $unpublishedEntriesInstance             Result instance
 125          */
 126         public final function getUnpublishedEntriesInstance () {
 127                 return $this->unpublishedEntriesInstance;
 128         }
 129
 130         /**
 131          * Prepares a "local" instance of a StoreableCriteria class with all node
 132          * data for insert/update queries. This data set contains data from *this*
 133          * (local) node.
 134          *
 135          * @return      $dataSetInstance        An instance of a StoreableCriteria class
 136          */
 137         private function prepareLocalDataSetInstance () {
 138                 // Get node/request instances
 139                 $nodeInstance = NodeObjectFactory::createNodeInstance();
 140                 $requestInstance = ApplicationHelper::getSelfInstance()->getRequestInstance();
 141
 142                 // Get a dataset instance
 143                 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
 144
 145                 // Set the primary key
 146                 $dataSetInstance->setUniqueKey(self::DB_COLUMN_NODE_ID);
 147
 148                 // Get ip:port combination and "explode" it
 149                 $ipPort = $nodeInstance->getAddressPortArray();
 150
 151                 // Make sure both is valid
 152                 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
 153
 154                 // Get an array of all accepted object types
 155                 $objectList = $nodeInstance->getListFromAcceptedObjectTypes();
 156
 157                 // Make sure this is an array
 158                 assert(is_array($objectList));
 159
 160                 // Add public node data
 161                 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_MODE       , $requestInstance->getRequestElement('mode'));
 162                 $dataSetInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP     , $ipPort[0]);
 163                 $dataSetInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT     , $ipPort[1]);
 164                 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_ID         , $nodeInstance->getNodeId());
 165                 $dataSetInstance->addCriteria(self::DB_COLUMN_SESSION_ID      , $nodeInstance->getSessionId());
 166                 $dataSetInstance->addCriteria(self::DB_COLUMN_PRIVATE_KEY_HASH, $nodeInstance->getPrivateKeyHash());
 167                 $dataSetInstance->addCriteria(self::DB_COLUMN_ACCEPTED_OBJECTS, implode(BaseHubNode::OBJECT_LIST_SEPARATOR, $objectList));
 168
 169                 // Return it
 170                 return $dataSetInstance;
 171         }
 172
 173         /**
 174          * Checks whether the local (*this*) node is registered in the DHT by
 175          * checking if the external ip/port is found.
 176          *
 177          * @return      $isRegistered   Whether *this* node is registered in the DHT
 178          */
 179         public function isLocalNodeRegistered () {
 180                 // Is there cache?
 181                 if (!isset($GLOBALS[__METHOD__])) {
 182                         // Get a search criteria instance
 183                         $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
 184
 185                         // Get node instance
 186                         $nodeInstance = NodeObjectFactory::createNodeInstance();
 187
 188                         // Get ip:port combination and "explode" it
 189                         $ipPort = $nodeInstance->getAddressPortArray();
 190
 191                         /*
 192                          * Make sure both is not 'invalid' which means that the resolver
 193                          * didn't work.
 194                          */
 195                         assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
 196
 197                         // Add ip:port/node id as criteria
 198                         $searchInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP, $ipPort[0]);
 199                         $searchInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT, $ipPort[1]);
 200                         $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID    , $nodeInstance->getNodeId());
 201                         $searchInstance->setLimit(1);
 202
 203                         // Query database and get a result instance back
 204                         $resultInstance = $this->doSelectByCriteria($searchInstance);
 205
 206                         // Cache result of if there is an entry, valid() will tell us if an entry is there
 207                         $GLOBALS[__METHOD__] = $resultInstance->valid();
 208                 } // END - if
 209
 210                 // Return result
 211                 return $GLOBALS[__METHOD__];
 212         }
 213
 214         /**
 215          * Registeres the local (*this*) node with its data in the DHT.
 216          *
 217          * @return      void
 218          */
 219         public function registerLocalNode () {
 220                 // Assert to make sure this method is called with no record in DB (the actual backend of the DHT)
 221                 assert(!$this->isLocalNodeRegistered());
 222
 223                 // Get prepared data set instance
 224                 $dataSetInstance = $this->prepareLocalDataSetInstance();
 225
 226                 // "Insert" this dataset instance completely into the database
 227                 $this->queryInsertDataSet($dataSetInstance);
 228         }
 229
 230         /**
 231          * Updates local (*this*) node data in DHT, this is but not limited to the
 232          * session id, ip number (and/or hostname) and port number.
 233          *
 234          * @return      void
 235          */
 236         public function updateLocalNode () {
 237                 // Assert to make sure this method is called with one record in DB (the actual backend of the DHT)
 238                 assert($this->isLocalNodeRegistered());
 239
 240                 // Get node instance
 241                 $nodeInstance = NodeObjectFactory::createNodeInstance();
 242
 243                 // Get search criteria
 244                 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
 245
 246                 // Search for node id and limit it to one entry
 247                 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeInstance->getNodeId());
 248                 $searchInstance->setLimit(1);
 249
 250                 // Get a prepared dataset instance
 251                 $dataSetInstance = $this->prepareLocalDataSetInstance();
 252
 253                 // Set search instance
 254                 $dataSetInstance->setSearchInstance($searchInstance);
 255
 256                 // Update DHT database record
 257                 $this->queryUpdateDataSet($dataSetInstance);
 258         }
 259
 260         /**
 261          * Finds a node locally by given session id
 262          *
 263          * @param       $sessionId      Session id to lookup
 264          * @return      $nodeData       Node data array
 265          */
 266         public function findNodeLocalBySessionId ($sessionId) {
 267                 // Get search criteria
 268                 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
 269
 270                 // Search for session id and limit it to one entry
 271                 $searchInstance->addCriteria(self::DB_COLUMN_SESSION_ID, $sessionId);
 272                 $searchInstance->setLimit(1);
 273
 274                 // Query database and get a result instance back
 275                 $resultInstance = $this->doSelectByCriteria($searchInstance);
 276
 277                 // Return result instance
 278                 return $resultInstance;
 279         }
 280
 281         /**
 282          * Registeres a node by given message data.
 283          *
 284          * @param       $messageData            An array of all message data
 285          * @param       $handlerInstance        An instance of a Handleable class
 286          * @return      void
 287          */
 288         public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance) {
 289                 // Get a data set instance
 290                 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
 291
 292                 // Set primary key (session id)
 293                 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
 294
 295                 // Add all array elements
 296                 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
 297
 298                 // Remove 'node_list'
 299                 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
 300
 301                 // Run the "INSERT" query
 302                 $this->queryInsertDataSet($dataSetInstance);
 303         }
 304
 305         /**
 306          * Updates an existing entry in node list
 307          *
 308          * @param       $messageData            An array of all message data
 309          * @param       $handlerInstance        An instance of a Handleable class
 310          * @param       $searchInstance         An instance of LocalSearchCriteria class
 311          * @return      void
 312          */
 313         public function updateNodeByMessageData (array $messageData, Handleable $handlerInstance, LocalSearchCriteria $searchInstance) {
 314                 // Get a data set instance
 315                 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
 316
 317                 // Add search instance
 318                 $dataSetInstance->setSearchInstance($searchInstance);
 319
 320                 // Set primary key (session id)
 321                 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
 322
 323                 // Add all array elements
 324                 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
 325
 326                 // Remove 'node_list'
 327                 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
 328
 329                 // Run the "UPDATE" query
 330                 $this->queryUpdateDataSet($dataSetInstance);
 331         }
 332
 333         /**
 334          * Determines whether the given node data is already inserted in the DHT
 335          *
 336          * @param       $nodeData               An array with valid node data
 337          * @return      $isRegistered   Whether the given node data is already inserted
 338          */
 339         public function isNodeRegistered (array $nodeData) {
 340                 // Assert on array elements
 341                 assert(isset($nodeData[self::DB_COLUMN_NODE_ID]));
 342
 343                 // Get search criteria
 344                 $searchInstance = $this->prepareSearchInstance($nodeData);
 345
 346                 // Query database and get a result instance back
 347                 $resultInstance = $this->doSelectByCriteria(
 348                         // Search instance
 349                         $searchInstance,
 350                         // Only look for these array elements ("keys")
 351                         array(
 352                                 self::DB_COLUMN_NODE_ID     => TRUE,
 353                                 self::DB_COLUMN_EXTERNAL_IP => TRUE,
 354                                 self::DB_COLUMN_LISTEN_PORT => TRUE,
 355                         )
 356                 );
 357
 358                 // Check if there is an entry
 359                 $isRegistered = $resultInstance->valid();
 360
 361                 // Return registration status
 362                 return $isRegistered;
 363         }
 364
 365         /**
 366          * Registers a node with given data in the DHT. If the node is already
 367          * registered this method shall throw an exception.
 368          *
 369          * @param       $nodeData       An array with valid node data
 370          * @return      void
 371          * @throws      NodeAlreadyRegisteredException  If the node is already registered
 372          */
 373         public function registerNode (array $nodeData) {
 374                 // Assert on array elements
 375                 assert(isset($nodeData[self::DB_COLUMN_NODE_ID]));
 376
 377                 // Is the node registered?
 378                 if ($this->isNodeRegistered($nodeData)) {
 379                         // Throw an exception
 380                         throw new NodeAlreadyRegisteredException(array($this, $nodeData), self::EXCEPTION_NODE_ALREADY_REGISTERED);
 381                 } // END - if
 382
 383                 // @TODO Unimplemented part
 384                 $this->partialStub('nodeData=' . print_r($nodeData, TRUE));
 385         }
 386
 387         /**
 388          * Updates a node's entry in the DHT with given data. This will enrich or
 389          * just update already exsiting data. If the node is not found this method
 390          * shall throw an exception.
 391          *
 392          * @param       $nodeData       An array with valid node data
 393          * @return      void
 394          * @throws      NodeDataMissingException        If the node's data is missing
 395          */
 396         public function updateNode (array $nodeData) {
 397                 // Assert on array elements
 398                 assert(isset($nodeData[self::DB_COLUMN_NODE_ID]));
 399
 400                 // Is the node registered?
 401                 if (!$this->isNodeRegistered($nodeData)) {
 402                         // No, then throw an exception
 403                         throw new NodeDataMissingException(array($this, $nodeData), self::EXCEPTION_NODE_NOT_REGISTERED);
 404                 } // END - if
 405
 406                 // Get a search instance
 407                 $searchInstance = $this->prepareSearchInstance($nodeData);
 408
 409                 // Get a data set instance
 410                 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
 411
 412                 // Add search instance
 413                 $dataSetInstance->setSearchInstance($searchInstance);
 414
 415                 // Set primary key (session id)
 416                 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
 417
 418                 // Get node instance
 419                 $nodeInstance = NodeObjectFactory::createNodeInstance();
 420
 421                 // Add all array elements
 422                 $nodeInstance->addArrayToDataSet($dataSetInstance, $nodeData);
 423
 424                 // Remove 'node_list'
 425                 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
 426
 427                 // Run the "UPDATE" query
 428                 $this->queryUpdateDataSet($dataSetInstance);
 429         }
 430
 431         /**
 432          * Checks whether there are unpublished entries
 433          *
 434          * @return      $hasUnpublished         Whether there are unpublished entries
 435          * @todo        Add minimum/maximum age limitations
 436          */
 437         public function hasUnpublishedEntries () {
 438                 // Get search instance
 439                 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
 440
 441                 // Add exclusion key which is the publish status
 442                 $searchInstance->addExcludeCriteria(NodeDistributedHashTableDatabaseWrapper::DB_COLUMN_PUBLICATION_STATUS, NodeDistributedHashTableDatabaseWrapper::PUBLICATION_STATUS_PENDING);
 443
 444                 // Remember search instance
 445                 $this->setSearchInstance($searchInstance);
 446
 447                 // Run the query
 448                 $this->unpublishedEntriesInstance = $this->doSelectByCriteria($searchInstance);
 449
 450                 // Check pending entries
 451                 $hasUnpublished = $this->unpublishedEntriesInstance->valid();
 452
 453                 // Return it
 454                 return $hasUnpublished;
 455         }
 456
 457         /**
 458          * Initializes publication of DHT entries. This does only prepare
 459          * publication. The next step is to pickup such prepared entries and publish
 460          * them by uploading to other (recently appeared) DHT members.
 461          *
 462          * @return      void
 463          * @todo        Add timestamp to dataset instance
 464          */
 465         public function initEntryPublication () {
 466                 /*
 467                  * Make sure that hasUnpublishedEntries() has been called first by
 468                  * asserting on the "cached" object instance. This "caching" saves some
 469                  * needless queries as this method shall be called immediately after
 470                  * hasUnpublishedEntries() returns TRUE.
 471                  */
 472                 assert($this->unpublishedEntriesInstance instanceof SearchableResult);
 473
 474                 // Result is still okay?
 475                 assert($this->unpublishedEntriesInstance->valid());
 476
 477                 // Remove 'publication_status'
 478                 $this->getSearchInstance()->unsetCriteria(self::DB_COLUMN_PUBLICATION_STATUS);
 479
 480                 // Make sure all entries are marked as pending, first get a dataset instance.
 481                 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
 482
 483                 // Add search instance
 484                 $dataSetInstance->setSearchInstance($this->getSearchInstance());
 485
 486                 // Set primary key (node id)
 487                 $dataSetInstance->setUniqueKey(self::DB_COLUMN_NODE_ID);
 488
 489                 // Add criteria (that should be set)
 490                 $dataSetInstance->addCriteria(self::DB_COLUMN_PUBLICATION_STATUS, self::PUBLICATION_STATUS_PENDING);
 491
 492                 // Run the "UPDATE" query
 493                 $this->queryUpdateDataSet($dataSetInstance);
 494         }
 495
 496         /**
 497          * Removes non-public data from given array.
 498          *
 499          * @param       $data   An array with possible non-public data that needs to be removed.
 500          * @return      $data   A cleaned up array with only public data.
 501          */
 502         public function removeNonPublicDataFromArray(array $data) {
 503                 // Currently call only inner method
 504                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-WRAPPER[' . $this->__toString() . ']: Calling parent::removeNonPublicDataFromArray(data) ...');
 505                 $data = parent::removeNonPublicDataFromArray($data);
 506                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-WRAPPER[' . $this->__toString() . ']: data[]=' . gettype($data));
 507
 508                 // Return cleaned data
 509                 return $data;
 510         }
 511
 512         /**
 513          * Find recipients for given package data and exclude the sender
 514          *
 515          * @param       $packageData    An array of valid package data
 516          * @return      $recipients             An indexed array with DHT recipients
 517          */
 518         public function getResultFromExcludedSender (array $packageData) {
 519                 // Assert on required array field
 520                 assert(isset($packageData[NetworkPackage::PACKAGE_DATA_SENDER]));
 521
 522                 // First creata a search instance
 523                 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
 524
 525                 // Then exclude 'sender' field as the sender is the current (*this*) node
 526                 $searchInstance->addExcludeCriteria(NodeDistributedHashTableDatabaseWrapper::DB_COLUMN_SESSION_ID, $packageData[NetworkPackage::PACKAGE_DATA_SENDER]);
 527
 528                 // Get a result instance back from DHT database wrapper.
 529                 $resultInstance = $this->doSelectByCriteria($searchInstance);
 530
 531                 // Return result instance
 532                 return $resultInstance;
 533         }
 534 }
 535
 536 // [EOF]
 537 ?>