3 * A NetworkPackage class. This class implements the Deliverable class because
4 * all network packages should be deliverable to other nodes. It further
5 * provides methods for reading raw content from template engines and feeding it
6 * to the stacker for undeclared packages.
8 * The factory method requires you to provide a compressor class (which must
9 * implement the Compressor interface). If you don't want any compression (not
10 * adviceable due to increased network load), please use the NullCompressor
11 * class and encode it with BASE64 for a more error-free transfer over the
14 * For performance reasons, this class should only be instantiated once and then
15 * used as a "pipe-through" class.
17 * @author Roland Haeder <webmaster@ship-simu.org>
19 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009, 2010 Hub Developer Team
20 * @license GNU GPL 3.0 or any newer version
21 * @link http://www.ship-simu.org
22 * @todo Needs to add functionality for handling the object's type
24 * This program is free software: you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation, either version 3 of the License, or
27 * (at your option) any later version.
29 * This program is distributed in the hope that it will be useful,
30 * but WITHOUT ANY WARRANTY; without even the implied warranty of
31 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
32 * GNU General Public License for more details.
34 * You should have received a copy of the GNU General Public License
35 * along with this program. If not, see <http://www.gnu.org/licenses/>.
37 class NetworkPackage extends BaseFrameworkSystem implements Deliverable, Registerable {
39 * Package mask for compressing package data:
40 * 1.) Compressor extension
41 * 2.) Raw package data
42 * 3.) Tags, seperated by semicolons, no semicolon is required if only one tag is needed
45 const PACKAGE_MASK = '%s:%s:%s:%s';
48 * Seperator for the above mask
50 const PACKAGE_MASK_SEPERATOR = ':';
53 * Array indexes for above mask, start with zero
55 const INDEX_COMPRESSOR_EXTENSION = 0;
56 const INDEX_PACKAGE_DATA = 1;
58 const INDEX_CHECKSUM = 3;
63 const PACKAGE_TAGS_SEPERATOR = ';';
66 * Stacker name for "undeclared" packages
68 const STACKER_NAME_UNDECLARED = 'undeclared';
71 * Stacker name for "declared" packages (which are ready to send out)
73 const STACKER_NAME_DECLARED = 'declared';
76 * Network target (alias): 'upper hubs'
78 const NETWORK_TARGET_UPPER_HUBS = 'upper';
81 * Protected constructor
85 protected function __construct () {
86 // Call parent constructor
87 parent::__construct(__CLASS__);
89 // We need to initialize a stack here for our packages even those
90 // which have no recipient address and stamp... ;-)
91 $stackerInstance = ObjectFactory::createObjectByConfiguredName('package_stacker_class');
93 // At last, set it in this class
94 $this->setStackerInstance($stackerInstance);
98 * Creates an instance of this class
100 * @param $compressorInstance A Compressor instance for compressing the content
101 * @return $packageInstance An instance of a Deliverable class
103 public final static function createNetworkPackage (Compressor $compressorInstance) {
105 $packageInstance = new NetworkPackage();
107 // Now set the compressor instance
108 $packageInstance->setCompressorInstance($compressorInstance);
110 // Return the prepared instance
111 return $packageInstance;
115 * "Getter" for hash from given content and helper instance
117 * @param $content Raw package content
118 * @param $helperInstance A BaseHubHelper instance
119 * @return $hash Hash for given package content
121 private function getHashFromContent ($content, BaseHubHelper $helperInstance) {
123 // @TODO crc32 is not good, but it needs to be fast
127 $helperInstance->getNodeInstance()->getSessionId() .
129 $this->getCompressorInstance()->getCompressorExtension()
137 * Delivers the given raw package data.
139 * @param $packageData Raw package data in an array
142 private function deliverPackage (array $packageData) {
144 * We need to disover every recipient, just in case we have a
145 * multi-recipient entry like 'upper' is. 'all' may be a not so good
146 * target because it causes an overload on the network and may be
147 * abused for attacking the network with large packages.
149 $discoveryInstance = PackageDiscoveryFactory::createPackageDiscoveryInstance();
151 // Discover all recipients, this may throw an exception
152 $discoveryInstance->discoverRecipients($packageData);
154 // Now get an iterator
155 $iteratorInstance = $discoveryInstance->getIterator();
157 // ... and begin iteration
158 while ($iteratorInstance->valid()) {
160 $currentRecipient = $iteratorInstance->current();
163 $this->debugOutput('PACKAGE: Package declared for recipient ' . $currentRecipient);
166 $packageData['recipient'] = $currentRecipient;
168 // And enqueue it to the writer class
169 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_DECLARED, $packageData);
171 // Skip to next entry
172 $iteratorInstance->next();
176 $discoveryInstance->clearRecipients();
180 * Sends a raw package out
182 * @param $packageData Raw package data in an array
185 private function sendRawPackage (array $packageData) {
187 * This package may become big, depending on the shared object size or
188 * delivered message size which shouldn't be so long (to save
189 * bandwidth). Because of the nature of the used protocol (TCP) we need
190 * to split it up into smaller pieces to fit it into a TCP frame.
192 * So first we need (again) a discovery class but now a protocol
193 * discovery to choose the right socket resource. The discovery class
194 * should take a look at the raw package data itself and then decide
195 * which (configurable!) protocol should be used for that type of
198 $discoveryInstance = SocketDiscoveryFactory::createSocketDiscoveryInstance();
200 // Now discover the right protocol
201 $socketResource = $discoveryInstance->discoverSocket($packageData);
202 die($socketResource);
206 * "Enqueues" raw content into this delivery class by reading the raw content
207 * from given template instance and pushing it on the 'undeclared' stack.
209 * @param $helperInstance A BaseHubHelper instance
212 public function enqueueRawDataFromTemplate (BaseHubHelper $helperInstance) {
213 // Get the raw content ...
214 $content = $helperInstance->getTemplateInstance()->getRawTemplateData();
216 // ... and compress it
217 $content = $this->getCompressorInstance()->compressStream($content);
219 // Add magic in front of it and hash behind it, including BASE64 encoding
220 $content = sprintf(self::PACKAGE_MASK,
221 // 1.) Compressor's extension
222 $this->getCompressorInstance()->getCompressorExtension(),
223 // 2.) Raw package content, encoded with BASE64
224 base64_encode($content),
226 implode(self::PACKAGE_TAGS_SEPERATOR, $helperInstance->getPackageTags()),
228 $this->getHashFromContent($content, $helperInstance)
231 // Now prepare the temporary array and push it on the 'undeclared' stack
232 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_UNDECLARED, array(
233 'sender' => $helperInstance->getNodeInstance()->getSessionId(),
234 'recipient' => self::NETWORK_TARGET_UPPER_HUBS,
235 'content' => $content,
240 * Checks wether a package has been enqueued for delivery.
242 * @return $isEnqueued Wether a package is enqueued
244 public function isPackageEnqueued () {
245 // Check wether the stacker is not empty
246 $isEnqueued = (($this->getStackerInstance()->isStackInitialized(self::STACKER_NAME_UNDECLARED)) && (!$this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_UNDECLARED)));
253 * Checks wether a package has been declared
255 * @return $isDeclared Wether a package is declared
257 public function isPackageDeclared () {
258 // Check wether the stacker is not empty
259 $isDeclared = (($this->getStackerInstance()->isStackInitialized(self::STACKER_NAME_DECLARED)) && (!$this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_DECLARED)));
266 * Delivers an enqueued package to the stated destination. If a non-session
267 * id is provided, recipient resolver is being asked (and instanced once).
268 * This allows that a single package is being delivered to multiple targets
269 * without enqueueing it for every target. If no target is provided or it
270 * can't be determined a NoTargetException is being thrown.
273 * @throws NoTargetException If no target can't be determined
275 public function declareEnqueuedPackage () {
276 // Make sure this method isn't working if there is no package enqueued
277 if (!$this->isPackageEnqueued()) {
278 // This is not fatal but should be avoided
279 // @TODO Add some logging here
283 // Now we know for sure there are packages to deliver, we can start
284 // with the first one.
285 $packageData = $this->getStackerInstance()->getNamed(self::STACKER_NAME_UNDECLARED);
287 // Finally, deliver the package
288 $this->deliverPackage($packageData);
290 // And remove it finally
291 $this->getStackerInstance()->popNamed(self::STACKER_NAME_UNDECLARED);
295 * Delivers the next declared package. Only one package per time will be sent
296 * because this may take time and slows down the whole delivery
301 public function deliverDeclaredPackage () {
302 // Sanity check if we have packages declared
303 if (!$this->isPackageDeclared()) {
304 // This is not fatal but should be avoided
305 // @TODO Add some logging here
309 // Get the package again
310 $packageData = $this->getStackerInstance()->getNamed(self::STACKER_NAME_DECLARED);
313 $this->sendRawPackage($packageData);
315 // And remove it finally
316 $this->getStackerInstance()->popNamed(self::STACKER_NAME_DECLARED);