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_HASH = 'private_key_hash';
34 const DB_COLUMN_NODE_MODE = 'node_mode';
35 const DB_COLUMN_ACCEPTED_OBJECTS = 'accepted_object_types';
36 const DB_COLUMN_NODE_LIST = 'node_list';
39 const EXCEPTION_NODE_ALREADY_REGISTERED = 0x800;
40 const EXCEPTION_NODE_NOT_REGISTERED = 0x801;
43 * Protected constructor
47 protected function __construct () {
48 // Call parent constructor
49 parent::__construct(__CLASS__);
53 * Creates an instance of this database wrapper by a provided user class
55 * @return $wrapperInstance An instance of the created wrapper class
57 public static final function createNodeDistributedHashTableDatabaseWrapper () {
59 $wrapperInstance = new NodeDistributedHashTableDatabaseWrapper();
61 // Set (primary!) table name
62 $wrapperInstance->setTableName(self::DB_TABLE_NODE_DHT);
64 // Return the instance
65 return $wrapperInstance;
69 * Prepares a "local" instance of a StoreableCriteria class with all node
70 * data for insert/update queries. This data set contains data from *this*
73 * @return $dataSetInstance An instance of a StoreableCriteria class
75 private function prepareLocalDataSetInstance () {
76 // Get node/request instances
77 $nodeInstance = Registry::getRegistry()->getInstance('node');
78 $requestInstance = ApplicationHelper::getSelfInstance()->getRequestInstance();
80 // Get a dataset instance
81 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
83 // Set the primary key
84 $dataSetInstance->setUniqueKey(self::DB_COLUMN_NODE_ID);
86 // Get ip:port combination and "explode" it
87 $ipPort = $nodeInstance->getAddressPortArray();
89 // Make sure both is valid
90 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
92 // Get an array of all accepted object types
93 $objectList = $nodeInstance->getListFromAcceptedObjectTypes();
95 // Make sure this is an array
96 assert(is_array($objectList));
98 // Add public node data
99 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_MODE , $requestInstance->getRequestElement('mode'));
100 $dataSetInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP , $ipPort[0]);
101 $dataSetInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT , $ipPort[1]);
102 $dataSetInstance->addCriteria(self::DB_COLUMN_NODE_ID , $nodeInstance->getNodeId());
103 $dataSetInstance->addCriteria(self::DB_COLUMN_SESSION_ID , $nodeInstance->getSessionId());
104 $dataSetInstance->addCriteria(self::DB_COLUMN_PRIVATE_KEY_HASH, $nodeInstance->getPrivateKeyHash());
105 $dataSetInstance->addCriteria(self::DB_COLUMN_ACCEPTED_OBJECTS, implode(BaseHubNode::OBJECT_LIST_SEPARATOR, $objectList));
108 return $dataSetInstance;
112 * Checks whether the local (*this*) node is registered in the DHT by
113 * checking if the external ip/port is found.
115 * @return $isRegistered Whether *this* node is registered in the DHT
117 public function isLocalNodeRegistered () {
119 if (!isset($GLOBALS[__METHOD__])) {
120 // Get a search criteria instance
121 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
124 $nodeInstance = Registry::getRegistry()->getInstance('node');
126 // Get ip:port combination and "explode" it
127 $ipPort = $nodeInstance->getAddressPortArray();
130 * Make sure both is not 'invalid' which means that the resolver
133 assert(($ipPort[0] !== 'invalid') && ($ipPort[1] !== 'invalid'));
135 // Add ip:port/node id as criteria
136 $searchInstance->addCriteria(self::DB_COLUMN_EXTERNAL_IP, $ipPort[0]);
137 $searchInstance->addCriteria(self::DB_COLUMN_LISTEN_PORT, $ipPort[1]);
138 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID , $nodeInstance->getNodeId());
139 $searchInstance->setLimit(1);
141 // Query database and get a result instance back
142 $resultInstance = $this->doSelectByCriteria($searchInstance);
144 // Cache result of if there is an entry, valid() will tell us if an entry is there
145 $GLOBALS[__METHOD__] = $resultInstance->valid();
149 return $GLOBALS[__METHOD__];
153 * Registeres the local (*this*) node with its data in the DHT.
157 public function registerLocalNode () {
158 // Assert to make sure this method is called with no record in DB (the actual backend of the DHT)
159 assert(!$this->isLocalNodeRegistered());
161 // Get prepared data set instance
162 $dataSetInstance = $this->prepareLocalDataSetInstance();
164 // "Insert" this dataset instance completely into the database
165 $this->queryInsertDataSet($dataSetInstance);
169 * Updates local (*this*) node data in DHT, this is but not limited to the
170 * session id, ip number (and/or hostname) and port number.
174 public function updateLocalNode () {
175 // Assert to make sure this method is called with one record in DB (the actual backend of the DHT)
176 assert($this->isLocalNodeRegistered());
179 $nodeInstance = Registry::getRegistry()->getInstance('node');
181 // Get search criteria
182 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
184 // Search for node id and limit it to one entry
185 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeInstance->getNodeId());
186 $searchInstance->setLimit(1);
188 // Get a prepared dataset instance
189 $dataSetInstance = $this->prepareLocalDataSetInstance();
191 // Set search instance
192 $dataSetInstance->setSearchInstance($searchInstance);
194 // Update DHT database record
195 $this->queryUpdateDataSet($dataSetInstance);
199 * Finds a node locally by given session id
201 * @param $sessionId Session id to lookup
202 * @return $nodeData Node data array
204 public function findNodeLocalBySessionId ($sessionId) {
205 // Get search criteria
206 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
208 // Search for session id and limit it to one entry
209 $searchInstance->addCriteria(self::DB_COLUMN_SESSION_ID, $sessionId);
210 $searchInstance->setLimit(1);
212 // Query database and get a result instance back
213 $resultInstance = $this->doSelectByCriteria($searchInstance);
215 // Return result instance
216 return $resultInstance;
220 * Registeres a node by given message data.
222 * @param $messageData An array of all message data
223 * @param $handlerInstance An instance of a HandleableMessage class
226 public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance) {
227 // Get a data set instance
228 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
230 // Set primary key (session id)
231 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
233 // Add all array elements
234 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
236 // Remove 'node_list'
237 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
239 // Run the "INSERT" query
240 $this->queryInsertDataSet($dataSetInstance);
244 * Updates an existing entry in node list
246 * @param $messageData An array of all message data
247 * @param $handlerInstance An instance of a HandleableMessage class
248 * @param $searchInstance An instance of LocalSearchCriteria class
251 public function updateNodeByMessageData (array $messageData, Handleable $handlerInstance, LocalSearchCriteria $searchInstance) {
252 // Get a data set instance
253 $dataSetInstance = ObjectFactory::createObjectByConfiguredName('dataset_criteria_class', array(self::DB_TABLE_NODE_DHT));
255 // Add search instance
256 $dataSetInstance->setSearchInstance($searchInstance);
258 // Set primary key (session id)
259 $dataSetInstance->setUniqueKey(self::DB_COLUMN_SESSION_ID);
261 // Add all array elements
262 $handlerInstance->addArrayToDataSet($dataSetInstance, $messageData);
264 // Remove 'node_list'
265 $dataSetInstance->unsetCriteria(self::DB_COLUMN_NODE_LIST);
267 // Run the "UPDATE" query
268 $this->queryUpdateDataSet($dataSetInstance);
272 * Determines whether the given node data is already inserted in the DHT
274 * @param $nodeData An array with valid node data
275 * @return $isRegistered Whether the given node data is already inserted
277 public function isNodeRegistered (array $nodeData) {
278 // Get search criteria
279 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
281 // Search for node id and limit it to one entry
282 $searchInstance->addCriteria(self::DB_COLUMN_NODE_ID, $nodeData[self::DB_COLUMN_NODE_ID]);
283 $searchInstance->setLimit(1);
285 // Query database and get a result instance back
286 $resultInstance = $this->doSelectByCriteria(
289 // Only look for these array elements ("keys")
291 self::DB_COLUMN_NODE_ID => TRUE,
292 self::DB_COLUMN_EXTERNAL_IP => TRUE,
293 self::DB_COLUMN_LISTEN_PORT => TRUE,
297 // Check if there is an entry
298 $isRegistered = $resultInstance->valid();
300 // Return registration status
301 return $isRegistered;
305 * Registers a node with given data in the DHT. If the node is already
306 * registered this method shall throw an exception.
308 * @param $nodeData An array with valid node data
310 * @throws NodeAlreadyRegisteredException If the node is already registered
312 public function registerNode (array $nodeData) {
313 // Is the node registered?
314 if ($this->isNodeRegistered($nodeData)) {
315 // Throw an exception
316 throw new NodeAlreadyRegisteredException(array($this, $nodeData), self::EXCEPTION_NODE_ALREADY_REGISTERED);
319 // @TODO Unimplemented part
320 $this->partialStub('nodeData=' . print_r($nodeData, TRUE));
324 * Updates a node's entry in the DHT with given data. This will enrich or
325 * just update already exsiting data. If the node is not found this method
326 * shall throw an exception.
328 * @param $nodeData An array with valid node data
330 * @throws NodeDataMissingException If the node's data is missing
332 public function updateNode (array $nodeData) {
333 // Is the node registered?
334 if (!$this->isNodeRegistered($nodeData)) {
335 // No, then throw an exception
336 throw new NodeDataMissingException(array($this, $nodeData), self::EXCEPTION_NODE_NOT_REGISTERED);
339 // @TODO Unimplemented part
340 $this->partialStub('nodeData=' . print_r($nodeData, TRUE));