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 * Checks whether the hash generated from package content is the same ("valid") as given
74 * @param $chunkSplits An array from a splitted chunk
75 * @return $isValid Whether the hash is "valid"
77 private function isChunkHashValid (array $chunkSplits) {
78 // Now hash the raw data again
79 $chunkHash = $this->getCryptoInstance()->hashString($chunkSplits[2], $chunkSplits[0], false);
82 //* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: chunkHash=' . $chunkHash . ',chunkSplits[0]=' . $chunkSplits[0] . ',chunkSplits[1]=' . $chunkSplits[1]);
85 $isValid = ($chunkSplits[0] === $chunkHash);
92 * Checks whether the given serial number is valid
94 * @param $serialNumber A serial number from a chunk
95 * @return $isValid Whether the serial number is valid
97 private function isSerialNumberValid ($serialNumber) {
99 $isValid = ((strlen($serialNumber) == PackageFragmenter::MAX_SERIAL_LENGTH) && ($this->bigintval($serialNumber, false) === $serialNumber));
106 * Adds all chunks if the last one verifies as a 'final chunk'.
108 * @param $chunks An array with chunks, the last one should be a 'final'
110 * @throws FinalChunkVerificationException If the final chunk does not start with 'EOP:'
112 public function addAllChunksWithFinal (array $chunks) {
113 // Validate final chunk
114 if (!$this->isValidFinalChunk($chunks)) {
115 // Last chunk is not valid
116 throw new FinalChunkVerificationException(array($this, $chunks), BaseListener::EXCEPTION_FINAL_CHUNK_VERIFICATION);
119 // Add all chunks to the FIFO stacker
120 foreach ($chunks as $chunk) {
122 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP, $chunk);
127 * Checks whether unhandled chunks are available
129 * @return $unhandledChunks Whether unhandled chunks are left
131 public function ifUnhandledChunksWithFinalAvailable () {
132 // Simply check if the stacker is not empty
133 $unhandledChunks = $this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP) === false;
136 return $unhandledChunks;
140 * Handles available chunks by processing one-by-one (not all together,
141 * this would slow-down the whole application) with the help of an
146 public function handleAvailableChunksWithFinal () {
147 // First check if there are undhandled chunks available
148 assert($this->ifUnhandledChunksWithFinalAvailable());
150 // Get an entry from the stacker
151 $chunk = $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
153 // Split the string with proper separator character
154 $chunkSplits = explode(PackageFragmenter::CHUNK_DATA_HASH_SEPARATOR, $chunk);
157 * Make sure three elements are always found:
162 assert(count($chunkSplits) == 3);
164 // Is the generated hash from data same ("valid") as given hash?
165 if (!$this->isChunkHashValid($chunkSplits)) {
167 $this->debugOutput('CHUNK-HANDLER: Chunk content is not validating against given hash.');
169 // Re-request this chunk (trust the hash in index # 0)
170 $this->rerequestChunkBySplitsArray($chunkSplits);
172 // Don't process this chunk
176 // Is the serial number valid (chars 0-9, length equals PackageFragmenter::MAX_SERIAL_LENGTH)?
177 if (!$this->isSerialNumberValid($chunkSplits[1])) {
179 $this->debugOutput('CHUNK-HANDLER: Chunk serial number is invalid.');
181 // Re-request this chunk
182 $this->rerequestChunkBySplitsArray($chunkSplits);
184 // Don't process this chunk
189 * It is now known that (as long as the hash algorithm has no
190 * collisions) the content is the same as the sender sends it to this
193 * And also the serial number is valid (basicly) at this point.
195 die('chunk=' . $chunk . chr(10));