application/hub/main/decoder/package/class_PackageDecoder.php

   1 <?php
   2 /**
   3  * A Package decoder class
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   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
  10  *
  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.
  15  *
  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.
  20  *
  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/>.
  23  */
  24 class PackageDecoder extends BaseDecoder implements Decodeable {
  25         /**
  26          * Name for stacker for received packages
  27          */
  28         const STACKER_NAME_DECODED_PACKAGE = 'decoded_package';
  29
  30         /**
  31          * Protected constructor
  32          *
  33          * @return      void
  34          */
  35         protected function __construct () {
  36                 // Call parent constructor
  37                 parent::__construct(__CLASS__);
  38         }
  39
  40         /**
  41          * Creates an instance of this class
  42          *
  43          * @param       $stackerInstance        An instance of a Stackable class
  44          * @return      $decoderInstance        An instance of a Decodeable class
  45          */
  46         public final static function createPackageDecoder (Stackable $stackerInstance) {
  47                 // Get new instance
  48                 $decoderInstance = new PackageDecoder();
  49
  50                 // Init stacker for received packages
  51                 $stackerInstance->initStack(self::STACKER_NAME_DECODED_PACKAGE);
  52
  53                 // Set the stacker instance here
  54                 $decoderInstance->setStackerInstance($stackerInstance);
  55
  56                 // Get a singleton network package instance
  57                 $packageInstance = NetworkPackageFactory::createNetworkPackageInstance();
  58
  59                 // And set it in this decoder
  60                 $decoderInstance->setPackageInstance($packageInstance);
  61
  62                 // Return the prepared instance
  63                 return $decoderInstance;
  64         }
  65
  66         /**
  67          * Checks whether the assoziated stacker for raw package data has some entries left
  68          *
  69          * @return      $unhandledDataLeft      Whether some unhandled raw package data is left
  70          */
  71         public function ifUnhandledRawPackageDataLeft () {
  72                 // Check it
  73                 $unhandledDataLeft = (!$this->getStackerInstance()->isStackEmpty(ChunkHandler::STACKER_NAME_ASSEMBLED_RAW_DATA));
  74
  75                 // Return it
  76                 return $unhandledDataLeft;
  77         }
  78
  79         /**
  80          * Handles raw package data by decoding it
  81          *
  82          * @return      void
  83          */
  84         public function handleRawPackageData () {
  85                 // Assert on it to make sure the next popNamed() call won't throw an exception
  86                 assert($this->ifUnhandledRawPackageDataLeft());
  87
  88                 // "Pop" the next raw package content
  89                 $rawPackageContent = $this->getStackerInstance()->popNamed(ChunkHandler::STACKER_NAME_ASSEMBLED_RAW_DATA);
  90
  91                 // "Decode" the raw package content by using the NetworkPackage instance
  92                 $decodedData = $this->getPackageInstance()->decodeRawContent($rawPackageContent);
  93
  94                 // Next get a recipient-discovery instance
  95                 $discoveryInstance = PackageDiscoveryFactory::createPackageDiscoveryInstance();
  96
  97                 // ... then disover all recipient (might be only one), this package may shall be forwarded
  98                 $discoveryInstance->discoverRawRecipients($decodedData);
  99
 100                 // Check for 'recipient' field (the 'sender' field and others are ignored here)
 101                 if ($discoveryInstance->isRecipientListEmpty()) {
 102                         // The recipient is this node so next stack it on 'decoded_package'
 103                         $this->getStackerInstance()->pushNamed(self::STACKER_NAME_DECODED_PACKAGE, $decodedData);
 104                 } else {
 105                         // Forward the package to the next node
 106                         $this->getPackageInstance()->forwardRawPackage($decodedData);
 107                 }
 108         }
 109
 110         /**
 111          * Checks whether decoded packages have arrived (for this peer)
 112          *
 113          * @return      $ifRawPackagesLeft      Whether decoded packages have arrived
 114          */
 115         public function ifDeocedPackagesLeft () {
 116                 // Check it ...
 117                 $ifRawPackagesLeft = (!$this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_DECODED_PACKAGE));
 118
 119                 // ... return it
 120                 return $ifRawPackagesLeft;
 121         }
 122
 123         /**
 124          * Handles received decoded packages internally (recipient is this node)
 125          *
 126          * @return      void
 127          */
 128         public function handleDecodedPackage () {
 129                 // Assert on amount
 130                 assert($this->ifDeocedPackagesLeft());
 131
 132                 // Get the next entry (assoziative array)
 133                 $decodedData = $this->getStackerInstance()->popNamed(self::STACKER_NAME_DECODED_PACKAGE);
 134
 135                 // Handle it
 136                 $this->getPackageInstance()->handleRawData($decodedData);
 137         }
 138 }
 139
 140 // [EOF]
 141 ?>