3 * A PackageAssembler class to assemble a package content stream fragemented
4 * by PackageFragmenter back to a raw package data array.
6 * @author Roland Haeder <webmaster@shipsimu.org>
8 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 Hub Developer Team
9 * @license GNU GPL 3.0 or any newer version
10 * @link http://www.shipsimu.org
12 * This program is free software: you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation, either version 3 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program. If not, see <http://www.gnu.org/licenses/>.
25 class PackageAssembler extends BaseHubSystem implements Assembler, Registerable {
29 private $pendingData = '';
32 * Private call-back methods
34 private $callbacks = array();
37 * Protected constructor
41 protected function __construct () {
42 // Call parent constructor
43 parent::__construct(__CLASS__);
47 * Creates an instance of this class
49 * @param $packageInstance An instance of a Receivable class
50 * @return $assemblerInstance An instance of an Assembler class
52 public static final function createPackageAssembler (Receivable $packageInstance) {
54 $assemblerInstance = new PackageAssembler();
56 // Set package instance here
57 $assemblerInstance->setPackageInstance($packageInstance);
59 // Create an instance of a raw data input stream
60 $streamInstance = ObjectFactory::createObjectByConfiguredName('node_raw_data_input_stream_class');
63 $assemblerInstance->setInputStreamInstance($streamInstance);
65 // Now get a chunk handler instance
66 $handlerInstance = ChunkHandlerFactory::createChunkHandlerInstance();
68 // Set handler instance
69 $assemblerInstance->setHandlerInstance($handlerInstance);
71 // Get stacker instance
72 $stackerInstance = ObjectFactory::createObjectByConfiguredName('multiple_message_stacker_class');
75 $assemblerInstance->setStackerInstance($stackerInstance);
77 // Return the prepared instance
78 return $assemblerInstance;
82 * Checks whether the input buffer (stacker to be more preceise) is empty.
84 * @return $isInputBufferEmpty Whether the input buffer is empty
86 private function ifInputBufferIsEmpty () {
88 $isInputBufferEmpty = $this->getPackageInstance()->getStackerInstance()->isStackEmpty(NetworkPackage::STACKER_NAME_DECODED_HANDLED);
91 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': isInputBufferEmpty=' . intval($isInputBufferEmpty));
94 return $isInputBufferEmpty;
98 * Checks whether given package content is completed (start/end markers are found)
100 * @param $packageContent An array with two elements: 'raw_data' and 'error_code'
101 * @return $isCompleted Whether the given package content is completed
103 private function isPackageContentCompleted (array $packageContent) {
105 $isCompleted = $this->ifStartEndMarkersSet($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]);
112 * Assembles the content from $packageContent. This method does only
113 * initialize the whole process by creating a call-back which will then
114 * itself (99.9% of all cases) "explode" the decoded data stream and add
115 * it to a chunk assembler queue.
117 * If the call-back method or this would attempt to assemble the package
118 * chunks and (maybe) re-request some chunks from the sender, this would
119 * take to much time and therefore slow down this node again.
121 * @param $packageContent An array with two elements: 'raw_data' and 'error_code'
123 * @throws UnsupportedPackageCodeHandlerException If the package code handler is not implemented
125 public function chunkPackageContent (array $packageContent) {
126 // Validate the package content array again
128 (isset($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA])) &&
129 (isset($packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]))
132 // Construct call-back name from package error code
133 $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]] = 'handlePackageBy' . $this->convertToClassName($packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]);
135 // Abort if the call-back method is not there
136 if (!method_exists($this, $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]])) {
137 // Throw an exception
138 throw new UnsupportedPackageCodeHandlerException(array($this, $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]], $packageContent), BaseListener::EXCEPTION_UNSUPPORTED_PACKAGE_CODE_HANDLER);
142 call_user_func(array($this, $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]]), $packageContent);
145 /**************************************************************************
146 * Call-back methods for above method *
147 **************************************************************************/
150 * Call-back handler to handle unhandled package data. This method
151 * "explodes" the string with the chunk separator from PackageFragmenter
152 * class, does some low checks on it and feeds it into another queue for
153 * verification and re-request for bad chunks.
155 * @param $packageContent An array with two elements: 'raw_data' and 'error_code'
158 private function handlePackageByUnhandledPackage (array $packageContent) {
160 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ']: packageData[' . BaseRawDataHandler::PACKAGE_RAW_DATA . ']=' . $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]);
162 // Check for some conditions
163 if ((!$this->ifInputBufferIsEmpty()) || (!$this->isPackageContentCompleted($packageContent))) {
164 // Last chunk is not valid, so wait for more
165 $this->pendingData .= $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA];
168 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': Partial data received. Waiting for more ... ( ' . strlen($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]) . ' bytes)');
171 /* DEBUG */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': packageContent=' . print_r($packageContent, TRUE) . ',chunks='.print_r($chunks, TRUE));
176 * Checks whether the assembler's pending data is empty which means it has
177 * no pending data left for handling ... ;-)
179 * @return $ifPendingDataIsEmpty Whether pending data is empty
181 public function isPendingDataEmpty () {
183 $ifPendingDataIsEmpty = empty($this->pendingData);
186 return $ifPendingDataIsEmpty;
190 * Handles the assembler's pending data
194 public function handlePendingData () {
196 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': Going to decode ' . strlen($this->pendingData) . ' Bytes of pending data. pendingData=' . $this->pendingData);
198 // Assert on condition
199 assert(!$this->isPendingDataEmpty());
202 if (!$this->ifStartEndMarkersSet($this->pendingData)) {
203 // This will cause an assertition in next call, so simply wait for more data
204 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': Pending data of ' . strlen($this->pendingData) . ' Bytes are incomplete, waiting for more ...');
206 } elseif (substr_count($this->pendingData, BaseRawDataHandler::STREAM_START_MARKER) > 1) {
208 * Multiple messages found, so split off first message as the input
209 * stream can only handle one message per time.
214 $packageContent = array(
215 BaseRawDataHandler::PACKAGE_RAW_DATA => $this->getInputStreamInstance()->streamData($this->pendingData),
216 BaseRawDataHandler::PACKAGE_ERROR_CODE => BaseRawDataHandler::SOCKET_ERROR_UNHANDLED
219 // Clear pending data
220 $this->pendingData = '';
223 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': Last block of partial data received. A total of ' . strlen($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]) . ' bytes has been received.');
225 // Make sure last CHUNK_SEPARATOR is not there
226 if (substr($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA], -1, 1) == PackageFragmenter::CHUNK_SEPARATOR) {
228 $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA] = substr($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA], 0, -1);
232 * "explode" the string from 'raw_data' with chunk separator to
233 * get an array of chunks. These chunks must then be verified by
234 * their checksums. Also the final chunk must be handled.
236 $chunks = explode(PackageFragmenter::CHUNK_SEPARATOR, $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]);
238 // Add all chunks because the last final chunk is found
239 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER[' . __METHOD__ . ':' . __LINE__ . ': Going to add ' . count($chunks) . ' to chunk handler ...');
240 $this->getHandlerInstance()->addAllChunksWithFinal($chunks);