3 * A Node DHT facade class
5 * @author Roland Haeder <webmaster@ship-simu.org>
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.ship-simu.org
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.
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.
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/>.
24 class NodeDhtFacade extends BaseDht implements Distributable, Registerable {
26 * Protected constructor
30 protected function __construct () {
31 // Call parent constructor
32 parent::__construct(__CLASS__);
36 * Creates an instance of this class
38 * @return $dhtInstance An instance of a Distributable class
40 public final static function createNodeDhtFacade () {
42 $dhtInstance = new NodeDhtFacade();
44 // Get a database wrapper instance
45 $wrapperInstance = DatabaseWrapperFactory::createWrapperByConfiguredName('node_dht_db_wrapper_class');
47 // Set it in this class
48 $dhtInstance->setWrapperInstance($wrapperInstance);
50 // Return the prepared instance
55 * Initializes the distributed hash table (DHT)
58 * @todo Please implement this method
60 public function initDht () {
61 // Is the local node registered?
62 if ($this->getWrapperInstance()->isLocalNodeRegistered()) {
63 // Then only update session id
64 $this->getWrapperInstance()->updateLocalNode();
67 $this->getWrapperInstance()->registerLocalNode();
72 * Finds a node by given session id
74 * @param $sessionId Session id to lookup
75 * @return $nodeData Node data array
77 public function findNodeBySessionId ($sessionId) {
78 // Default is empty data array
81 // Call the wrapper to do the job and get back a result instance
82 $resultInstance = $this->getWrapperInstance()->findNodeBySessionId($sessionId);
84 // Is the next entry valid?
85 if ($resultInstance->next()) {
86 // Then load the entry
87 $nodeData = $resultInstance->current();
95 * Registers an other node with this node by given message data. The
96 * following data must always be present:
98 * - session-id (for finding the node's record together with below data)
99 * - external-ip (hostname or IP number)
100 * - listen-port (TCP/UDP listen port for inbound connections)
102 * @param $messageArray An array with all minimum message data
103 * @param $handlerInstance An instance of a Handleable class
104 * @param $forceUpdate Optionally force update, don't register (default: register if not found)
106 * @throws NodeSessionIdVerficationException If the node was not found and update is forced
108 public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance, $forceUpdate = FALSE) {
109 // Get a search criteria class
110 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
113 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: messageData=' . print_r($messageData, true));
115 // Search for the node's session id and external IP/hostname + TCP/UDP listen port
116 foreach ($handlerInstance->getSearchData() as $key) {
118 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: messageData[' . $key . ']=' . $messageData[$key]);
121 assert(isset($messageData[$key]));
124 $searchInstance->addCriteria(str_replace('my-', '', $key), $messageData[$key]);
127 // Only one entry is fine
128 $searchInstance->setLimit(1);
131 $resultInstance = $this->getWrapperInstance()->doSelectByCriteria($searchInstance);
133 // Is there already an entry?
134 if ($resultInstance->next()) {
135 // Entry found, so update it
136 $this->getWrapperInstance()->updateNodeByMessageData($messageData, $handlerInstance, $searchInstance);
137 } elseif ($forceUpdate === FALSE) {
138 // Nothing found, so register it
139 $this->getWrapperInstance()->registerNodeByMessageData($messageData, $handlerInstance);
142 * Do not register non-existent nodes here. This is maybe fatal,
143 * caused by "stolen" session id and/or not matching IP
144 * number/port combination.
146 throw new NodeSessionIdVerficationException(array($this, $messageData), BaseHubSystem::EXCEPTION_NODE_SESSION_ID_NOT_VERIFYING);
149 // Save last exception
150 $handlerInstance->setLastException($this->getWrapperInstance()->getLastException());
154 * Queries the local DHT data(base) for a node list with all supported
155 * object types except the node by given session id.
157 * @param $messageData An array with message data from a node_list request
158 * @param $excludeKey Array key which should be excluded
159 * @param $andKey Array of $separator-separated list of elements which all must match
160 * @param $separator Sepator char (1st parameter for explode() call)
161 * @return $nodeList An array with all found nodes
163 public function queryLocalNodeListExceptByMessageData (array $messageData, $excludeKey, $andKey, $separator) {
164 // Make sure both keys are there
165 assert((isset($messageData[$excludeKey])) && (isset($messageData[$andKey])));
168 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: messageData=' . print_r($messageData, true));
170 // Get a search criteria class
171 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
174 foreach (explode($separator, $messageData[$andKey]) as $criteria) {
176 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: andKey=' . $andKey . ',criteria=' . $criteria);
178 // Add it and leave any 'my-' prefix out
179 $searchInstance->addChoiceCriteria(str_replace('my-', '', $andKey), $criteria);
183 $searchInstance->addExcludeCriteria(str_replace('my-', '', $excludeKey), $messageData[$excludeKey]);
185 // Only X entries are fine
186 $searchInstance->setLimit($this->getConfigInstance()->getConfigEntry('node_dht_list_limit'));
189 $resultInstance = $this->getWrapperInstance()->doSelectByCriteria($searchInstance);
193 while ($resultInstance->next()) {
195 array_push($nodeList, $resultInstance->current());
198 // Save last exception
199 $handlerInstance->setLastException($this->getWrapperInstance()->getLastException());
201 // Return node list (array)