5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2011 Hub Developer Team
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.ship-simu.org
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.
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.
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/>.
24 class ChunkHandler extends BaseHandler implements HandleableChunks, Registerable {
26 * Stacker for chunks with final EOP
28 const STACKER_NAME_CHUNKS_WITH_FINAL_EOP = 'final_chunks';
31 * Protected constructor
35 protected function __construct () {
36 // Call parent constructor
37 parent::__construct(__CLASS__);
40 $this->setHandlerName('chunk');
44 * Creates an instance of this class
46 * @return $handlerInstance An instance of a chunk Handler class
48 public final static function createChunkHandler () {
50 $handlerInstance = new ChunkHandler();
53 $stackerInstance = ObjectFactory::createObjectByConfiguredName('chunk_handler_stacker_class');
56 $stackerInstance->initStacker(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
58 // Set the stacker in this handler
59 $handlerInstance->setStackerInstance($stackerInstance);
61 // Get a crypto instance ...
62 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
64 // ... and set it in this handler
65 $handlerInstance->setCryptoInstance($cryptoInstance);
67 // Return the prepared instance
68 return $handlerInstance;
72 * Adds all chunks if the last one verifies as a 'final chunk'.
74 * @param $chunks An array with chunks, the last one should be a 'final'
76 * @throws FinalChunkVerificationException If the final chunk does not start with 'EOP:'
78 public function addAllChunksWithFinal (array $chunks) {
79 // Validate final chunk
80 if (!$this->isValidFinalChunk($chunks)) {
81 // Last chunk is not valid
82 throw new FinalChunkVerificationException(array($this, $chunks), BaseListener::EXCEPTION_FINAL_CHUNK_VERIFICATION);
85 // Add all chunks to the FIFO stacker
86 foreach ($chunks as $chunk) {
88 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP, $chunk);
93 * Checks whether unhandled chunks are available
95 * @return $unhandledChunks Whether unhandled chunks are left
97 public function ifUnhandledChunksWithFinalAvailable () {
98 // Simply check if the stacker is not empty
99 $unhandledChunks = $this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP) === false;
102 return $unhandledChunks;
106 * Handles available chunks by processing one-by-one (not all together,
107 * this would slow-down the whole application) with the help of an
112 public function handleAvailableChunksWithFinal () {
113 // First check if there are undhandled chunks available
114 assert($this->ifUnhandledChunksWithFinalAvailable());
116 // Get an entry from the stacker
117 $chunk = $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
119 // Split the string with proper separator character
120 $chunkSplits = explode(PackageFragmenter::CHUNK_DATA_HASH_SEPARATOR, $chunk);
123 * Make sure three elements are always found:
128 assert(count($chunkSplits) == 3);
130 // Now hash the raw data again
131 $chunkHash = $this->getCryptoInstance()->hashString($chunkSplits[2], $chunkSplits[0], false);
134 /* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: chunkHash=' . $chunkHash . ',chunkSplits[0]=' . $chunkSplits[0] . ',chunkSplits[1]=' . $chunkSplits[1]);
137 if ($chunkSplits[0] != $chunkHash) {
138 // Re-request this chunk (trust the hash in index # 0)
139 $this->rerequestChunkBySplitsArray($chunkSplits);
141 // Don't process this chunk
146 * It is now known that (as long as the hash algorithm has no
147 * collisions) the content is the same as the sender sends it to this
150 die('chunk=' . $chunk . chr(10));