return $dhtInstance;
}
+ /**
+ * Registers/updates an entry in the DHT with given data from $dhtData
+ * array. Different DHT implemtations may handle this differently as they
+ * may enrich the data with more meta data.
+ *
+ * @param $dhtData A valid array with DHT-related data (e.g. node/peer data)
+ * @return void
+ * @todo Does the data need to be enriched?
+ */
+ protected function insertDataIntoDht (array $dhtData) {
+ // Check if there is already an entry for given node_id
+ if ($this->getWrapperInstance()->isNodeRegisteredByNodeId($dhtData[NodeDistributedHashTableDatabaseWrapper::DB_COLUMN_NODE_ID])) {
+ /*
+ * Update existing record. Please note that this step is not secure
+ * (e.g. DHT poisoning) it would be good to implement some checks if
+ * the both node owner trust each other (see sub-project 'DSHT').
+ */
+ $this->getWrapperInstance()->updateNodeEntry($nodeData);
+ } else {
+ /*
+ * Inserts given node data into the DHT. As above, this step does
+ * currently not perform any security checks.
+ */
+ $this->getWrapperInstance()->registerNodeByData($nodeData);
+ }
+ }
+
/**
* Initializes the distributed hash table (DHT)
*
* @return void
- * @todo Please implement this method
*/
public function initDht () {
// Is the local node registered?
// No, so register it
$this->getWrapperInstance()->registerLocalNode();
}
+
+ // Change state
+ $this->getStateInstance()->dhtHasInitialized();
+ }
+
+ /**
+ * Bootstraps the DHT by sending out a message to all available nodes
+ * (including itself). This step helps the node to get to know more nodes
+ * which can be queried later for object distribution.
+ *
+ * @return void
+ */
+ public function bootstrapDht () {
+ // Get a helper instance
+ $helperInstance = ObjectFactory::createObjectByConfiguredName('dht_bootstrap_helper_class');
+
+ // Load the announcement descriptor
+ $helperInstance->loadDescriptorXml($this);
+
+ // Compile all variables
+ $helperInstance->getTemplateInstance()->compileConfigInVariables();
+
+ // "Publish" the descriptor by sending it to the bootstrap/list nodes
+ $helperInstance->sendPackage($this);
+
+ // Change state
+ $this->getStateInstance()->dhtHasBooted();
}
/**
* Finds a node locally by given session id
*
* @param $sessionId Session id to lookup
- * @return $nodeData Node data array
+ * @return $nodeData Node-data array
*/
public function findNodeLocalBySessionId ($sessionId) {
// Default is empty data array
$nodeData = array();
- // Call the wrapper to do the job and get back a result instance
+ /*
+ * Call the wrapper to do the job and get back a result instance. There
+ * will come back zero or one entry from the wrapper.
+ */
$resultInstance = $this->getWrapperInstance()->findNodeLocalBySessionId($sessionId);
// Is the next entry valid?
if ($resultInstance->next()) {
- // Then load the entry
+ /*
+ * Then load the first entry (more entries are being ignored and
+ * should not happen).
+ */
$nodeData = $resultInstance->current();
} // END - if
$searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
// Debug message
- /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: messageData=' . print_r($messageData, true));
+ /* 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($handlerInstance->getSearchData()));
// Search for the node's session id and external IP/hostname + TCP/UDP listen port
foreach ($handlerInstance->getSearchData() as $key) {
// Debug message
- /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: messageData[' . $key . ']=' . $messageData[$key]);
+ /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',key=' . $key);
// Is it there?
assert(isset($messageData[$key]));
+ // Debug message
+ /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',messageData[' . $key . ']=' . $messageData[$key]);
+
// Add criteria
$searchInstance->addCriteria(str_replace('my-', '', $key), $messageData[$key]);
} // END - foreach
assert((isset($messageData[$excludeKey])) && (isset($messageData[$andKey])));
// Debug message
- /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: messageData=' . print_r($messageData, true));
+ /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: state=' . $this->getPrintableState() . ',messageData=' . print_r($messageData, true));
// Get a search criteria class
$searchInstance = ObjectFactory::createObjectByConfiguredName('search_criteria_class');
// Add all keys
foreach (explode($separator, $messageData[$andKey]) as $criteria) {
// Debug message
- /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE: andKey=' . $andKey . ',criteria=' . $criteria);
+ /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: andKey=' . $andKey . ',criteria=' . $criteria);
// Add it and leave any 'my-' prefix out
$searchInstance->addChoiceCriteria(str_replace('my-', '', $andKey), $criteria);
// Get node list
$nodeList = array();
while ($resultInstance->next()) {
+ // Get current element (it should be an array, and have at least 1 entry)
+ $current = $resultInstance->current();
+ assert(is_array($current));
+ assert(count($current) > 0);
+
+ // Debug message
+ /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: current(' . count($current) . ')[' . gettype($current) . ']=' . print_r($current, TRUE));
+
+ /*
+ * Remove some keys as they should not be published.
+ */
+ unset($current[$this->getWrapperInstance()->getIndexKey()]);
+
// Add this entry
- array_push($nodeList, $resultInstance->current());
+ array_push($nodeList, $current);
} // END - while
// Save last exception
// Return node list (array)
return $nodeList;
}
+
+ /**
+ * Inserts given node list array (from earlier database result produced by
+ * an other node) into the DHT. This array origins from above method
+ * queryLocalNodeListExceptByMessageData().
+ *
+ * @param $nodeList An array from an earlier database result instance
+ * @return void
+ */
+ public function insertNodeList (array $nodeList) {
+ // If no node is in the list (array), skip the rest of this method
+ if (count($nodeList) == 0) {
+ // Debug message
+ self::createDebugInstance(__CLASS__)->debugOutput('DHT-FACADE[' . __LINE__ . ']: No node record has been returned.');
+
+ // Abort here
+ return;
+ } // END - if
+
+ // Put them all into a stack
+ foreach ($nodeList as $nodeData) {
+ // Insert all entries
+ $this->getStackerInstance()->pushNamed(self::STACKER_NAME_INSERT_NODE, $nodeData);
+ } // END - foreach
+ }
}
// [EOF]
projects / hub.git / blobdiff