application/hub/main/package/assembler/class_PackageAssembler.php

   1 <?php
   2 /**
   3  * A PackageAssembler class to assemble a package content stream fragemented
   4  * by PackageFragmenter back to a raw package data array.
   5  *
   6  * @author              Roland Haeder <webmaster@shipsimu.org>
   7  * @version             0.0.0
   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
  11  *
  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.
  16  *
  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.
  21  *
  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/>.
  24  */
  25 class PackageAssembler extends BaseHubSystem implements Assembler, Registerable {
  26         /**
  27          * Pending data
  28          */
  29         private $pendingData = '';
  30
  31         /**
  32          * Private call-back methods
  33          */
  34         private $callbacks = array();
  35
  36         /**
  37          * Protected constructor
  38          *
  39          * @return      void
  40          */
  41         protected function __construct () {
  42                 // Call parent constructor
  43                 parent::__construct(__CLASS__);
  44         }
  45
  46         /**
  47          * Creates an instance of this class
  48          *
  49          * @param       $packageInstance        An instance of a Receivable class
  50          * @return      $assemblerInstance      An instance of an Assembler class
  51          */
  52         public static final function createPackageAssembler (Receivable $packageInstance) {
  53                 // Get new instance
  54                 $assemblerInstance = new PackageAssembler();
  55
  56                 // Set package instance here
  57                 $assemblerInstance->setPackageInstance($packageInstance);
  58
  59                 // Create an instance of a raw data input stream
  60                 $streamInstance = ObjectFactory::createObjectByConfiguredName('node_raw_data_input_stream_class');
  61
  62                 // And set it
  63                 $assemblerInstance->setInputStreamInstance($streamInstance);
  64
  65                 // Return the prepared instance
  66                 return $assemblerInstance;
  67         }
  68
  69         /**
  70          * Checks whether the input buffer (stacker to be more preceise) is empty.
  71          *
  72          * @return      $isInputBufferEmpty             Whether the input buffer is empty
  73          */
  74         private function ifInputBufferIsEmpty () {
  75                 // Check it
  76                 $isInputBufferEmpty = $this->getPackageInstance()->getStackerInstance()->isStackEmpty(NetworkPackage::STACKER_NAME_DECODED_HANDLED);
  77
  78                 // Debug message
  79                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER: isInputBufferEmpty=' . intval($isInputBufferEmpty));
  80
  81                 // Return it
  82                 return $isInputBufferEmpty;
  83         }
  84
  85         /**
  86          * Checks whether given package content is completed (start/end markers are found)
  87          *
  88          * @param       $packageContent         An array with two elements: 'raw_data' and 'error_code'
  89          * @return      $isCompleted            Whether the given package content is completed
  90          */
  91         private function isPackageContentCompleted (array $packageContent) {
  92                 // Check both
  93                 $isCompleted = $this->ifStartEndMarkersSet($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]);
  94
  95                 // Return status
  96                 return $isCompleted;
  97         }
  98
  99         /**
 100          * Assembles the content from $packageContent. This method does only
 101          * initialize the whole process by creating a call-back which will then
 102          * itself (99.9% of all cases) "explode" the decoded data stream and add
 103          * it to a chunk assembler queue.
 104          *
 105          * If the call-back method or this would attempt to assemble the package
 106          * chunks and (maybe) re-request some chunks from the sender, this would
 107          * take to much time and therefore slow down this node again.
 108          *
 109          * @param       $packageContent         An array with two elements: 'raw_data' and 'error_code'
 110          * @return      void
 111          * @throws      UnsupportedPackageCodeHandlerException  If the package code handler is not implemented
 112          */
 113         public function chunkPackageContent (array $packageContent) {
 114                 // Validate the package content array again
 115                 assert(
 116                         (isset($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA])) &&
 117                         (isset($packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]))
 118                 );
 119
 120                 // Construct call-back name from package error code
 121                 $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]] = 'handlePackageBy' . $this->convertToClassName($packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]);
 122
 123                 // Abort if the call-back method is not there
 124                 if (!method_exists($this, $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]])) {
 125                         // Throw an exception
 126                         throw new UnsupportedPackageCodeHandlerException(array($this, $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]], $packageContent), BaseListener::EXCEPTION_UNSUPPORTED_PACKAGE_CODE_HANDLER);
 127                 } // END - if
 128
 129                 // Call it back
 130                 call_user_func(array($this, $this->callbacks[$packageContent[BaseRawDataHandler::PACKAGE_ERROR_CODE]]), $packageContent);
 131         }
 132
 133         /**************************************************************************
 134          *                 Call-back methods for above method                     *
 135          **************************************************************************/
 136
 137         /**
 138          * Call-back handler to handle unhandled package data. This method
 139          * "explodes" the string with the chunk separator from PackageFragmenter
 140          * class, does some low checks on it and feeds it into another queue for
 141          * verification and re-request for bad chunks.
 142          *
 143          * @param       $packageContent         An array with two elements: 'raw_data' and 'error_code'
 144          * @return      void
 145          */
 146         private function handlePackageByUnhandledPackage (array $packageContent) {
 147                 // Debug message
 148                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER: packageData[' . BaseRawDataHandler::PACKAGE_RAW_DATA . ']=' . $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]);
 149
 150                 // Check for some conditions
 151                 if ((!$this->ifInputBufferIsEmpty()) || (!$this->isPackageContentCompleted($packageContent))) {
 152                         // Last chunk is not valid, so wait for more
 153                         $this->pendingData .= $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA];
 154
 155                         // Debug message
 156                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER: Partial data received. Waiting for more ... ( ' . strlen($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]) . ' bytes)');
 157                 } else {
 158                         // Debug message
 159                         /* DEBUG */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER: packageContent=' . print_r($packageContent, TRUE) . ',chunks='.print_r($chunks, TRUE));
 160                 }
 161         }
 162
 163         /**
 164          * Checks whether the assembler's pending data is empty which means it has
 165          * no pending data left for handling ... ;-)
 166          *
 167          * @return      $ifPendingDataIsEmpty   Whether pending data is empty
 168          */
 169         public function isPendingDataEmpty () {
 170                 // A simbple check
 171                 $ifPendingDataIsEmpty = empty($this->pendingData);
 172
 173                 // Return it
 174                 return $ifPendingDataIsEmpty;
 175         }
 176
 177         /**
 178          * Handles the assembler's pending data
 179          *
 180          * @return      void
 181          */
 182         public function handlePendingData () {
 183                 // Debug output
 184                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER: Going to decode ' . strlen($this->pendingData) . ' Bytes of pending data. pendingData=' . $this->pendingData);
 185
 186                 // Assert on condition
 187                 assert(!$this->isPendingDataEmpty());
 188
 189                 // Init fake array
 190                 $packageContent = array(
 191                         BaseRawDataHandler::PACKAGE_RAW_DATA   => $this->getInputStreamInstance()->streamData($this->pendingData),
 192                         BaseRawDataHandler::PACKAGE_ERROR_CODE => BaseRawDataHandler::SOCKET_ERROR_UNHANDLED
 193                 );
 194
 195                 // Clear pending data
 196                 $this->pendingData = '';
 197
 198                 // Debug message
 199                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('PACKAGE-ASSEMBLER: Last block of partial data received. A total of ' . strlen($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]) . ' bytes has been received.');
 200
 201                 // Make sure last CHUNK_SEPARATOR is not there
 202                 if (substr($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA], -1, 1) == PackageFragmenter::CHUNK_SEPARATOR) {
 203                         // Remove it
 204                         $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA] = substr($packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA], 0, -1);
 205                 } // END - if
 206
 207                 /*
 208                  * "explode" the string from 'raw_data' with chunk separator to
 209                  * get an array of chunks. These chunks must then be verified by
 210                  * their checksums. Also the final chunk must be handled.
 211                  */
 212                 $chunks = explode(PackageFragmenter::CHUNK_SEPARATOR, $packageContent[BaseRawDataHandler::PACKAGE_RAW_DATA]);
 213
 214                 // Now get a chunk handler instance
 215                 $handlerInstance = ChunkHandlerFactory::createChunkHandlerInstance();
 216
 217                 // Add all chunks because the last final chunk is found
 218                 $handlerInstance->addAllChunksWithFinal($chunks);
 219         }
 220 }
 221
 222 // [EOF]
 223 ?>