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 * Registers/updates an entry in the DHT with given data from $dhtData
56 * array. Different DHT implemtations may handle this differently as they
57 * may enrich the data with more meta data.
59 * @param $dhtData A valid array with DHT-related data (e.g. node/peer data)
61 * @todo Does this data need to be enriched with more meta data?
63 protected function insertDataIntoDht (array $dhtData) {
64 // Check if there is already an entry for given node_id
65 if ($this->getWrapperInstance()->isNodeRegistered($dhtData)) {
67 * Update existing record. Please note that this step is not secure
68 * (e.g. DHT poisoning) it would be good to implement some checks if
69 * the both node owner trust each other (see sub-project 'DSHT').
71 $this->getWrapperInstance()->updateNode($dhtData);
74 * Inserts given node data into the DHT. As above, this step does
75 * currently not perform any security checks.
77 $this->getWrapperInstance()->registerNode($dhtData);
82 * Initializes the distributed hash table (DHT)
86 public function initDht () {
87 // Is the local node registered?
88 if ($this->getWrapperInstance()->isLocalNodeRegistered()) {
89 // Then only update session id
90 $this->getWrapperInstance()->updateLocalNode();
93 $this->getWrapperInstance()->registerLocalNode();
97 $this->getStateInstance()->dhtHasInitialized();
101 * Bootstraps the DHT by sending out a message to all available nodes
102 * (including itself). This step helps the node to get to know more nodes
103 * which can be queried later for object distribution.
107 public function bootstrapDht () {
108 // Get a helper instance
109 $helperInstance = ObjectFactory::createObjectByConfiguredName('dht_bootstrap_helper_class');
111 // Load the announcement descriptor
112 $helperInstance->loadDescriptorXml($this);
114 // Compile all variables
115 $helperInstance->getTemplateInstance()->compileConfigInVariables();
117 // "Publish" the descriptor by sending it to the bootstrap/list nodes
118 $helperInstance->sendPackage($this);
121 $this->getStateInstance()->dhtHasBooted();
125 * Finds a node locally by given session id
127 * @param $sessionId Session id to lookup
128 * @return $nodeData Node-data array
130 public function findNodeLocalBySessionId ($sessionId) {
131 // Default is empty data array
135 * Call the wrapper to do the job and get back a result instance. There
136 * will come back zero or one entry from the wrapper.
138 $resultInstance = $this->getWrapperInstance()->findNodeLocalBySessionId($sessionId);
140 // Is the next entry valid?
141 if (($resultInstance->valid()) && ($resultInstance->next())) {
143 * Then load the first entry (more entries are being ignored and
144 * should not happen).
146 $nodeData = $resultInstance->current();
154 * Registers an other node with this node by given message data. The
155 * following data must always be present:
157 * - session-id (for finding the node's record together with below data)
158 * - external-ip (hostname or IP number)
159 * - listen-port (TCP/UDP listen port for inbound connections)
161 * @param $messageArray An array with all minimum message data
162 * @param $handlerInstance An instance of a Handleable class
163 * @param $forceUpdate Optionally force update, don't register (default: register if not found)
165 * @throws NodeSessionIdVerficationException If the node was not found and update is forced
167 public function registerNodeByMessageData (array $messageData, Handleable $handlerInstance, $forceUpdate = FALSE) {
168 // Get a search criteria class
169 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
172 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',messageData=' . print_r($messageData, TRUE) . ',handlerInstance=' . $handlerInstance->__toString() . ',forceUpdate=' . intval($forceUpdate) . ',count(getSearchData())=' . count($handlerInstance->getSearchData()));
174 // Search for the node's session id and external IP/hostname + TCP/UDP listen port
175 foreach ($handlerInstance->getSearchData() as $key) {
177 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',key=' . $key);
180 assert(isset($messageData[$key]));
183 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',messageData[' . $key . ']=' . $messageData[$key]);
186 $searchInstance->addCriteria(str_replace('my-', '', $key), $messageData[$key]);
189 // Only one entry is fine
190 $searchInstance->setLimit(1);
193 $resultInstance = $this->getWrapperInstance()->doSelectByCriteria($searchInstance);
195 // Is there already an entry?
196 if ($resultInstance->valid()) {
197 // Entry found, so update it
198 $this->getWrapperInstance()->updateNodeByMessageData($messageData, $handlerInstance, $searchInstance);
199 } elseif ($forceUpdate === FALSE) {
200 // Nothing found, so register it
201 $this->getWrapperInstance()->registerNodeByMessageData($messageData, $handlerInstance);
204 * Do not register non-existent nodes here. This is maybe fatal,
205 * caused by "stolen" session id and/or not matching IP
206 * number/port combination.
208 throw new NodeSessionIdVerficationException(array($this, $messageData), BaseHubSystem::EXCEPTION_NODE_SESSION_ID_NOT_VERIFYING);
211 // Save last exception
212 $handlerInstance->setLastException($this->getWrapperInstance()->getLastException());
216 * Queries the local DHT data(base) for a node list with all supported
217 * object types except the node by given session id.
219 * @param $messageData An array with message data from a node_list request
220 * @param $handlerInstance An instance of a Handleable class
221 * @param $excludeKey Array key which should be excluded
222 * @param $andKey Array of $separator-separated list of elements which all must match
223 * @param $separator Sepator char (1st parameter for explode() call)
224 * @return $nodeList An array with all found nodes
226 public function queryLocalNodeListExceptByMessageData (array $messageData, Handleable $handlerInstance, $excludeKey, $andKey, $separator) {
227 // Make sure both keys are there
228 assert((isset($messageData[$excludeKey])) && (isset($messageData[$andKey])));
231 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',messageData=' . print_r($messageData, TRUE));
233 // Get a search criteria class
234 $searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
237 foreach (explode($separator, $messageData[$andKey]) as $criteria) {
239 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: andKey=' . $andKey . ',criteria=' . $criteria);
241 // Add it and leave any 'my-' prefix out
242 $searchInstance->addChoiceCriteria(str_replace('my-', '', $andKey), $criteria);
246 $searchInstance->addExcludeCriteria(str_replace('my-', '', $excludeKey), $messageData[$excludeKey]);
248 // Only X entries are fine
249 $searchInstance->setLimit($this->getConfigInstance()->getConfigEntry('node_dht_list_limit'));
252 $resultInstance = $this->getWrapperInstance()->doSelectByCriteria($searchInstance);
256 while ($resultInstance->next()) {
257 // Get current element (it should be an array, and have at least 1 entry)
258 $current = $resultInstance->current();
259 assert(is_array($current));
260 assert(count($current) > 0);
263 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: current(' . count($current) . ')[' . gettype($current) . ']=' . print_r($current, TRUE));
266 * Remove some keys as they should not be published.
268 unset($current[$this->getWrapperInstance()->getIndexKey()]);
271 array_push($nodeList, $current);
274 // Save last exception
275 $handlerInstance->setLastException($this->getWrapperInstance()->getLastException());
277 // Return node list (array)
282 * Inserts given node list array (from earlier database result produced by
283 * an other node) into the DHT. This array origins from above method
284 * queryLocalNodeListExceptByMessageData().
286 * @param $nodeList An array from an earlier database result instance
289 public function insertNodeList (array $nodeList) {
290 // If no node is in the list (array), skip the rest of this method
291 if (count($nodeList) == 0) {
293 self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: No node record has been returned.');
299 // Put them all into a stack
300 foreach ($nodeList as $nodeData) {
301 // Insert all entries
302 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_INSERT_NODE, $nodeData);