3 * A database wrapper for distributed hash tables
5 * @author Roland Haeder <webmaster@shipsimu.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.shipsimu.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';
36 const DB_COLUMN_ACCEPTED_OBJECTS = 'accepted_object_types';
37 const DB_COLUMN_NODE_LIST = 'node_list';
40 const EXCEPTION_NODE_ALREADY_REGISTERED = 0x800;
41 const EXCEPTION_NODE_NOT_REGISTERED = 0x801;
44 * Protected constructor
48 protected function __construct () {
49 // Call parent constructor
50 parent::__construct(__CLASS__);
54 * Creates an instance of this database wrapper by a provided user class
56 * @return $wrapperInstance An instance of the created wrapper class
58 public static final function createNodeDistributedHashTableDatabaseWrapper () {
60 $wrapperInstance = new NodeDistributedHashTableDatabaseWrapper();
62 // Set (primary!) table name
63 $wrapperInstance->setTableName(self::DB_TABLE_NODE_DHT);
65 // Return the instance
66 return $wrapperInstance;
70 * Prepares a "local" instance of a StoreableCriteria class with all node
71 * data for insert/update queries. This data set contains data from *this*
74 * @return $dataSetInstance An instance of a StoreableCriteria class
76 private function prepareLocalDataSetInstance () {
77 // Get node/request instances
78 $nodeInstance = Registry::getRegistry()->getInstance('node');
79 $requestInstance = ApplicationHelper::getSelfInstance()->getRequestInstance();
81 // Get a dataset instance
82 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
84 // Set the primary key
85 $dataSetInstance->setUniqueKey(self::DB_COLUMN_NODE_ID);
87 // Get ip:port combination and "explode" it
88 $ipPort = $nodeInstance->getAddressPortArray();
90 // Make sure both is valid
91 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
93 // Get an array of all accepted object types
94 $objectList = $nodeInstance->getListFromAcceptedObjectTypes();
96 // Make sure this is an array
97 assert(is_array($objectList));
99 // Add public node data
100 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_MODE , $requestInstance->getRequestElement('mode'));
101 $dataSetInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP , $ipPort[0]);
102 $dataSetInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT , $ipPort[1]);
103 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_ID , $nodeInstance->getNodeId());
104 $dataSetInstance->addCriteria(self::DB_COLUMN_SESSION_ID , $nodeInstance->getSessionId());
105 $dataSetInstance->addCriteria(self::DB_COLUMN_PRIVATE_KEY_HASH, $nodeInstance->getPrivateKeyHash());
106 $dataSetInstance->addCriteria(self::DB_COLUMN_ACCEPTED_OBJECTS, implode(BaseHubNode::OBJECT_LIST_SEPARATOR, $objectList));
109 return $dataSetInstance;
113 * Checks whether the local (*this*) node is registered in the DHT by
114 * checking if the external ip/port is found.
116 * @return $isRegistered Whether *this* node is registered in the DHT
118 public function isLocalNodeRegistered () {
120 if (!isset($GLOBALS[__METHOD__])) {
121 // Get a search criteria instance
122 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
125 $nodeInstance = Registry::getRegistry()->getInstance('node');
127 // Get ip:port combination and "explode" it
128 $ipPort = $nodeInstance->getAddressPortArray();
131 * Make sure both is not 'invalid' which means that the resolver
134 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
136 // Add ip:port/node id as criteria
137 $searchInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP, $ipPort[0]);
138 $searchInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT, $ipPort[1]);
139 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID , $nodeInstance->getNodeId());
140 $searchInstance->setLimit(1);
142 // Query database and get a result instance back
143 $resultInstance = $this->doSelectByCriteria($searchInstance);
145 // Cache result of if there is an entry, valid() will tell us if an entry is there
146 $GLOBALS[__METHOD__] = $resultInstance->valid();
150 return $GLOBALS[__METHOD__];
154 * Registeres the local (*this*) node with its data in the DHT.
158 public function registerLocalNode () {
159 // Assert to make sure this method is called with no record in DB (the actual backend of the DHT)
160 assert(!$this->isLocalNodeRegistered());
162 // Get prepared data set instance
163 $dataSetInstance = $this->prepareLocalDataSetInstance();
165 // "Insert" this dataset instance completely into the database
166 $this->queryInsertDataSet($dataSetInstance);
170 * Updates local (*this*) node data in DHT, this is but not limited to the
171 * session id, ip number (and/or hostname) and port number.
175 public function updateLocalNode () {
176 // Assert to make sure this method is called with one record in DB (the actual backend of the DHT)
177 assert($this->isLocalNodeRegistered());
180 $nodeInstance = Registry::getRegistry()->getInstance('node');
182 // Get search criteria
183 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
185 // Search for node id and limit it to one entry
186 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeInstance->getNodeId());
187 $searchInstance->setLimit(1);
189 // Get a prepared dataset instance
190 $dataSetInstance = $this->prepareLocalDataSetInstance();
192 // Set search instance
193 $dataSetInstance->setSearchInstance($searchInstance);
195 // Update DHT database record
196 $this->queryUpdateDataSet($dataSetInstance);
200 * Finds a node locally by given session id
202 * @param $sessionId Session id to lookup
203 * @return $nodeData Node data array
205 public function findNodeLocalBySessionId ($sessionId) {
206 // Get search criteria
207 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
209 // Search for session id and limit it to one entry
210 $searchInstance->addCriteria(self::DB_COLUMN_SESSION_ID, $sessionId);
211 $searchInstance->setLimit(1);
213 // Query database and get a result instance back
214 $resultInstance = $this->doSelectByCriteria($searchInstance);
216 // Return result instance
217 return $resultInstance;
221 * Registeres a node by given message data.
223 * @param $messageData An array of all message data
224 * @param $handlerInstance An instance of a HandleableMessage class
227 public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance) {
228 // Get a data set instance
229 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
231 // Set primary key (session id)
232 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
234 // Add all array elements
235 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
237 // Remove 'node_list'
238 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
240 // Run the "INSERT" query
241 $this->queryInsertDataSet($dataSetInstance);
245 * Updates an existing entry in node list
247 * @param $messageData An array of all message data
248 * @param $handlerInstance An instance of a HandleableMessage class
249 * @param $searchInstance An instance of LocalSearchCriteria class
252 public function updateNodeByMessageData (array $messageData, Handleable $handlerInstance, LocalSearchCriteria $searchInstance) {
253 // Get a data set instance
254 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
256 // Add search instance
257 $dataSetInstance->setSearchInstance($searchInstance);
259 // Set primary key (session id)
260 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
262 // Add all array elements
263 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
265 // Remove 'node_list'
266 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
268 // Run the "UPDATE" query
269 $this->queryUpdateDataSet($dataSetInstance);
273 * Determines whether the given node data is already inserted in the DHT
275 * @param $nodeData An array with valid node data
276 * @return $isRegistered Whether the given node data is already inserted
278 public function isNodeRegistered (array $nodeData) {
279 // Get search criteria
280 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
282 // Search for node id and limit it to one entry
283 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeData[self::DB_COLUMN_NODE_ID]);
284 $searchInstance->setLimit(1);
286 // Query database and get a result instance back
287 $resultInstance = $this->doSelectByCriteria(
290 // Only look for these array elements ("keys")
292 self::DB_COLUMN_NODE_ID => TRUE,
293 self::DB_COLUMN_EXTERNAL_IP => TRUE,
294 self::DB_COLUMN_LISTEN_PORT => TRUE,
298 // Check if there is an entry
299 $isRegistered = $resultInstance->valid();
301 // Return registration status
302 return $isRegistered;
306 * Registers a node with given data in the DHT. If the node is already
307 * registered this method shall throw an exception.
309 * @param $nodeData An array with valid node data
311 * @throws NodeAlreadyRegisteredException If the node is already registered
313 public function registerNode (array $nodeData) {
314 // Is the node registered?
315 if ($this->isNodeRegistered($nodeData)) {
316 // Throw an exception
317 throw new NodeAlreadyRegisteredException(array($this, $nodeData), self::EXCEPTION_NODE_ALREADY_REGISTERED);
320 // @TODO Unimplemented part
321 $this->partialStub('nodeData=' . print_r($nodeData, TRUE));
325 * Updates a node's entry in the DHT with given data. This will enrich or
326 * just update already exsiting data. If the node is not found this method
327 * shall throw an exception.
329 * @param $nodeData An array with valid node data
331 * @throws NodeDataMissingException If the node's data is missing
333 public function updateNode (array $nodeData) {
334 // Is the node registered?
335 if (!$this->isNodeRegistered($nodeData)) {
336 // No, then throw an exception
337 throw new NodeDataMissingException(array($this, $nodeData), self::EXCEPTION_NODE_NOT_REGISTERED);
340 // @TODO Unimplemented part
341 $this->partialStub('nodeData=' . print_r($nodeData, TRUE));