3 * A database wrapper for distributed hash tables
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 NodeDistributedHashTableDatabaseWrapper extends BaseDatabaseWrapper implements NodeDhtWrapper, Registerable {
25 // Constants for database table names
26 const DB_TABLE_NODE_DHT = 'node_dht';
28 // Constants for database column names
29 const DB_COLUMN_NODE_ID = 'node_id';
30 const DB_COLUMN_SESSION_ID = 'session_id';
31 const DB_COLUMN_EXTERNAL_IP = 'external_ip';
32 const DB_COLUMN_LISTEN_PORT = 'listen_port';
33 const DB_COLUMN_PRIVATE_KEY = 'private_key';
34 const DB_COLUMN_PRIVATE_KEY_HASH = 'private_key_hash';
35 const DB_COLUMN_NODE_TYPE = 'node_type';
38 * Protected constructor
42 protected function __construct () {
43 // Call parent constructor
44 parent::__construct(__CLASS__);
48 * Creates an instance of this database wrapper by a provided user class
50 * @return $wrapperInstance An instance of the created wrapper class
52 public static final function createNodeDistributedHashTableDatabaseWrapper () {
54 $wrapperInstance = new NodeDistributedHashTableDatabaseWrapper();
56 // Set (primary!) table name
57 $wrapperInstance->setTableName(self::DB_TABLE_NODE_DHT);
59 // Return the instance
60 return $wrapperInstance;
64 * Prepares a "local" instance of a StoreableCriteria class with all node
65 * data for insert/update queries. This data set contains data from *this*
68 * @return $dataSetInstance An instance of a StoreableCriteria class
70 private function prepareLocalDataSetInstance () {
71 // Get node/request instances
72 $nodeInstance = Registry::getRegistry()->getInstance('node');
73 $requestInstance = ApplicationHelper::getSelfInstance()->getRequestInstance();
75 // Get a dataset instance
76 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
78 // Set the primary key
79 $dataSetInstance->setUniqueKey(self::DB_COLUMN_NODE_ID);
81 // Get ip:port combination and "explode" it
82 $ipPort = $nodeInstance->getAddressPortArray();
84 // Make sure both is valid
85 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
87 // Add public node data
88 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_TYPE , $requestInstance->getRequestElement('mode'));
89 $dataSetInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP , $ipPort[0]);
90 $dataSetInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT , $ipPort[1]);
91 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_ID , $nodeInstance->getNodeId());
92 $dataSetInstance->addCriteria(self::DB_COLUMN_SESSION_ID , $nodeInstance->getSessionId());
93 $dataSetInstance->addCriteria(self::DB_COLUMN_PRIVATE_KEY_HASH, $nodeInstance->getPrivateKeyHash());
96 return $dataSetInstance;
100 * Checks whether the local (*this*) node is registered in the DHT by
101 * checking if the external ip/port is found.
103 * @return $isRegistered Whether *this* node is registered in the DHT
105 public function isLocalNodeRegistered () {
107 if (!isset($GLOBALS[__METHOD__])) {
108 // Get a search criteria instance
109 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
112 $nodeInstance = Registry::getRegistry()->getInstance('node');
114 // Get ip:port combination and "explode" it
115 $ipPort = $nodeInstance->getAddressPortArray());
117 // Make sure both is valid
118 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
120 // Add ip:port as criteria
121 $searchInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP, $ipPort[0]);
122 $searchInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT, $ipPort[1]);
123 $searchInstance->setLimit(1);
125 // Query database and get a result instance back
126 $resultInstance = $this->doSelectByCriteria($searchInstance);
128 // Cache result of if there is an entry, next() will tell us if the next entry is valid
129 $GLOBALS[__METHOD__] = $resultInstance->next();
133 return $GLOBALS[__METHOD__];
137 * Registeres the local (*this*) node with its data in the DHT.
141 public function registerLocalNode () {
142 // Assert to make sure this method is called with no record in DB (the actual backend of the DHT)
143 assert(!$this->isLocalNodeRegistered());
145 // Get prepared data set instance
146 $dataSetInstance = $this->prepareLocalDataSetInstance();
148 // "Insert" this dataset instance completely into the database
149 $this->queryInsertDataSet($dataSetInstance);
153 * Updates local (*this*) node data in DHT, this is but not limited to the
154 * session id, ip number (and/or hostname) and port number.
158 public function updateLocalNode () {
159 // Assert to make sure this method is called with one record in DB (the actual backend of the DHT)
160 assert($this->isLocalNodeRegistered());
163 $nodeInstance = Registry::getRegistry()->getInstance('node');
165 // Get search criteria
166 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
168 // Search for node id and limit it to one entry
169 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeInstance->getNodeId());
170 $searchInstance->setLimit(1);
172 // Get a prepared dataset instance
173 $dataSetInstance = $this->prepareLocalDataSetInstance();
175 // Set search instance
176 $dataSetInstance->setSearchInstance($searchInstance);
178 // Update DHT database record
179 $this->queryUpdateDataSet($dataSetInstance);
183 * Finds a node by given session id
185 * @param $sessionId Session id to lookup
186 * @return $nodeData Node data array
188 public function findNodeBySessionId ($sessionId) {
189 // Get search criteria
190 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
192 // Search for session id and limit it to one entry
193 $searchInstance->addCriteria(self::DB_COLUMN_SESSION_ID, $sessionId);
194 $searchInstance->setLimit(1);
196 // Query database and get a result instance back
197 $resultInstance = $this->doSelectByCriteria($searchInstance);
199 // Return result instance
200 return $resultInstance;
204 * Registeres a node by given message data.
206 * @param $messageData An array of all message data
207 * @param $handlerInstance An instance of a HandleableMessage class
210 public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance) {
211 // Get a data set instance
212 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
214 // Set primary key (session id)
215 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
217 // Add all array elements
218 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
220 // Run the "INSERT" query
221 $this->queryInsertDataSet($dataSetInstance);
225 * Updates an existing entry in node list
227 * @param $messageData An array of all message data
228 * @param $handlerInstance An instance of a HandleableMessage class
229 * @param $searchInstance An instance of LocalSearchCriteria class
232 public function updateNodeByMessageData (array $messageData, Handleable $handlerInstance, LocalSearchCriteria $searchInstance) {
233 // Get a data set instance
234 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
236 // Add search instance
237 $dataSetInstance->setSearchInstance($searchInstance);
239 // Set primary key (session id)
240 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
242 // Add all array elements
243 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
245 // Run the "UPDATE" query
246 $this->queryUpdateDataSet($dataSetInstance);