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_MODE = 'node_mode';
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_MODE , $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/node id as criteria
121 $searchInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP, $ipPort[0]);
122 $searchInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT, $ipPort[1]);
123 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID , $nodeInstance->getNodeId());
124 $searchInstance->setLimit(1);
126 // Query database and get a result instance back
127 $resultInstance = $this->doSelectByCriteria($searchInstance);
129 // Cache result of if there is an entry, next() will tell us if the next entry is valid
130 $GLOBALS[__METHOD__] = $resultInstance->next();
134 return $GLOBALS[__METHOD__];
138 * Registeres the local (*this*) node with its data in the DHT.
142 public function registerLocalNode () {
143 // Assert to make sure this method is called with no record in DB (the actual backend of the DHT)
144 assert(!$this->isLocalNodeRegistered());
146 // Get prepared data set instance
147 $dataSetInstance = $this->prepareLocalDataSetInstance();
149 // "Insert" this dataset instance completely into the database
150 $this->queryInsertDataSet($dataSetInstance);
154 * Updates local (*this*) node data in DHT, this is but not limited to the
155 * session id, ip number (and/or hostname) and port number.
159 public function updateLocalNode () {
160 // Assert to make sure this method is called with one record in DB (the actual backend of the DHT)
161 assert($this->isLocalNodeRegistered());
164 $nodeInstance = Registry::getRegistry()->getInstance('node');
166 // Get search criteria
167 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
169 // Search for node id and limit it to one entry
170 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeInstance->getNodeId());
171 $searchInstance->setLimit(1);
173 // Get a prepared dataset instance
174 $dataSetInstance = $this->prepareLocalDataSetInstance();
176 // Set search instance
177 $dataSetInstance->setSearchInstance($searchInstance);
179 // Update DHT database record
180 $this->queryUpdateDataSet($dataSetInstance);
184 * Finds a node locally by given session id
186 * @param $sessionId Session id to lookup
187 * @return $nodeData Node data array
189 public function findNodeLocalBySessionId ($sessionId) {
190 // Get search criteria
191 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
193 // Search for session id and limit it to one entry
194 $searchInstance->addCriteria(self::DB_COLUMN_SESSION_ID, $sessionId);
195 $searchInstance->setLimit(1);
197 // Query database and get a result instance back
198 $resultInstance = $this->doSelectByCriteria($searchInstance);
200 // Return result instance
201 return $resultInstance;
205 * Registeres a node by given message data.
207 * @param $messageData An array of all message data
208 * @param $handlerInstance An instance of a HandleableMessage class
211 public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance) {
212 // Get a data set instance
213 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
215 // Set primary key (session id)
216 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
218 // Add all array elements
219 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
221 // Run the "INSERT" query
222 $this->queryInsertDataSet($dataSetInstance);
226 * Updates an existing entry in node list
228 * @param $messageData An array of all message data
229 * @param $handlerInstance An instance of a HandleableMessage class
230 * @param $searchInstance An instance of LocalSearchCriteria class
233 public function updateNodeByMessageData (array $messageData, Handleable $handlerInstance, LocalSearchCriteria $searchInstance) {
234 // Get a data set instance
235 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
237 // Add search instance
238 $dataSetInstance->setSearchInstance($searchInstance);
240 // Set primary key (session id)
241 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
243 // Add all array elements
244 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
246 // Run the "UPDATE" query
247 $this->queryUpdateDataSet($dataSetInstance);