* Stacker for chunks with final EOP
*/
const STACKER_NAME_CHUNKS_WITH_FINAL_EOP = 'final_chunks';
+ const STACKER_NAME_ASSEMBLED_RAW_DATA = 'chunk_raw_data';
/**
* Chunk splits:
/**
* The final array for assembling the original package back together
*/
- private $finalPackageChunks = array(
- // Array for package content
- 'content' => array(),
- // ... and for the hashes
- 'hashes' => array(),
- // ... marker for that the final array is complete for assembling all chunks
- 'is_complete' => false
- );
+ private $finalPackageChunks = array();
+
+ /**
+ * Array of chunk hashes
+ */
+ private $chunkHashes = array();
+
+ /**
+ * Raw EOP chunk data in an array:
+ *
+ * 0 = Final hash,
+ * 1 = Hash of last chunk
+ */
+ private $eopChunk = array();
+
+ /**
+ * Raw package data
+ */
+ private $rawPackageData = '';
/**
* Protected constructor
// Set handler name
$this->setHandlerName('chunk');
+
+ // Initialize handler
+ $this->initHandler();
}
/**
// Init all stacker
$stackerInstance->initStacker(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
+ $stackerInstance->initStacker(self::STACKER_NAME_ASSEMBLED_RAW_DATA);
// Set the stacker in this handler
$handlerInstance->setStackerInstance($stackerInstance);
// ... and set it in this handler
$handlerInstance->setCryptoInstance($cryptoInstance);
+ // Get a fragmenter instance for later verification of serial numbers (e.g. if all are received)
+ $fragmenterInstance = FragmenterFactory::createFragmenterInstance('package');
+
+ // Set it in this handler
+ $handlerInstance->setFragmenterInstance($fragmenterInstance);
+
// Return the prepared instance
return $handlerInstance;
}
+ /**
+ * Initializes the handler
+ *
+ * @return void
+ */
+ private function initHandler () {
+ // Init finalPackageChunks
+ $this->finalPackageChunks = array(
+ // Array for package content
+ 'content' => array(),
+ // ... and for the hashes
+ 'hashes' => array(),
+ // ... marker for that the final array is complete for assembling all chunks
+ 'is_complete' => false,
+ // ... steps done to assemble all chunks
+ 'assemble_steps' => 0,
+ );
+
+ // ... chunkHashes:
+ $this->chunkHashes = array();
+
+ // ... eopChunk:
+ $this->eopChunk = array(
+ 0 => 'INVALID',
+ 1 => 'INVALID',
+ );
+ }
+
/**
* Checks whether the hash generated from package content is the same ("valid") as given
*
$this->finalPackageChunks['is_complete'] = true;
}
+ /**
+ * Sorts the chunks array by using the serial number as a sorting key. In
+ * most situations a call of ksort() is enough to accomblish this. So this
+ * method may only call ksort() on the chunks array.
+ *
+ * This method sorts 'content' and 'hashes' so both must have used the
+ * serial numbers as array indexes.
+ *
+ * @return void
+ */
+ private function sortChunksArray () {
+ // Sort 'content' first
+ ksort($this->finalPackageChunks['content']);
+
+ // ... then 'hashes'
+ ksort($this->finalPackageChunks['hashes']);
+ }
+
+ /**
+ * Prepares the package assemble by removing last chunks (last shall be
+ * hash chunk, pre-last shall be EOP chunk) and verify that all serial
+ * numbers are valid (same as PackageFragmenter class would generate).
+ *
+ * @return void
+ */
+ private function preparePackageAssmble () {
+ // Make sure both arrays have same count (this however should always be true)
+ assert(count($this->finalPackageChunks['hashes']) == count($this->finalPackageChunks['content']));
+
+ /*
+ * Remove last element (hash chunk) from 'hashes'. This hash will never
+ * be needed, so ignore it.
+ */
+ array_pop($this->finalPackageChunks['hashes']);
+
+ // ... and from 'content' as well but save it for later use
+ $this->chunkHashes = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::HASH_CHUNK_IDENTIFIER)));
+
+ // Remove EOP chunk and keep a copy of it
+ array_pop($this->finalPackageChunks['hashes']);
+ $this->eopChunk = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::END_OF_PACKAGE_IDENTIFIER)));
+
+ // Verify all serial numbers
+ $this->verifyChunkSerialNumbers();
+ }
+
+ /**
+ * Verifies all chunk serial numbers by using a freshly initialized
+ * fragmenter instance. Do ALWAYS sort the array and array_pop() the hash
+ * chunk before calling this method to avoid re-requests of many chunks.
+ *
+ * @return void
+ */
+ private function verifyChunkSerialNumbers () {
+ // Reset the serial number generator
+ $this->getFragmenterInstance()->resetSerialNumber();
+
+ // "Walk" through all (content) chunks
+ foreach ($this->finalPackageChunks['content'] as $serialNumber=>$content) {
+ // Get next serial number
+ $nextSerial = $this->getFragmenterInstance()->getNextHexSerialNumber();
+
+ // Debug output
+ //* NOISY-DEBUG */ $this->debugOutput('CHUNK-HANDLER: serialNumber=' . $serialNumber . ',nextSerial=' . $nextSerial);
+
+ // Is it not the same? Then re-request it
+ if ($serialNumber != $nextSerial) {
+ // This is invalid, so remove it
+ unset($this->finalPackageChunks['content'][$serialNumber]);
+ unset($this->finalPackageChunks['hashes'][$serialNumber]);
+
+ // And re-request it with valid serial number (and hash chunk)
+ $this->rerequestChunkBySerialNumber($nextSerial);
+ } // END - if
+ } // END - foreach
+ }
+
+ /**
+ * Assembles and verifies ("final check") chunks back together to the
+ * original package (raw data for the start). This method should only be
+ * called AFTER the EOP and final-chunk chunk have been removed.
+ *
+ * @return void
+ */
+ private function assembleAllChunksToPackage () {
+ // If chunkHashes is not filled, don't continue
+ assert(count($this->chunkHashes) > 0);
+
+ // Init raw package data string
+ $this->rawPackageData = '';
+
+ // That went well, so start assembling all chunks
+ foreach ($this->finalPackageChunks['content'] as $serialNumber=>$content) {
+ // Is this chunk valid? This should be the case
+ assert($this->isChunkHashValid(array(
+ self::CHUNK_SPLITS_INDEX_HASH => $this->finalPackageChunks['hashes'][$serialNumber],
+ self::CHUNK_SPLITS_INDEX_RAW_DATA => $content
+ )));
+
+ // ... and is also in the hash chunk?
+ assert(in_array($this->finalPackageChunks['hashes'][$serialNumber], $this->chunkHashes));
+
+ // Verification okay, add it to the raw data
+ $this->rawPackageData .= $content;
+ } // END - foreach
+
+ // Debug output
+ //* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: eopChunk[1]=' . $this->eopChunk[1] . ',' . chr(10) . 'index=' . (count($this->chunkHashes) - 2) . ',' . chr(10) . 'chunkHashes='.print_r($this->chunkHashes,true));
+
+ // The last chunk hash must match with the one from eopChunk[1]
+ assert($this->eopChunk[1] == $this->chunkHashes[count($this->chunkHashes) - 2]);
+ }
+
+ /**
+ * Verifies the finally assembled raw package data by comparing it against
+ * the final hash.
+ *
+ * @return void
+ */
+ private function verifyRawPackageData () {
+ // Hash the raw package data for final verification
+ $finalHash = $this->getCryptoInstance()->hashString($this->rawPackageData, $this->eopChunk[0], false);
+
+ // Is it the same?
+ assert($finalHash == $this->eopChunk[0]);
+ }
+
/**
* Adds all chunks if the last one verifies as a 'final chunk'.
*
// Make sure the final array is really completed
assert($this->ifUnassembledChunksAvailable());
- $this->partialStub('Please implement this method.');
+ // Count up stepping
+ $this->finalPackageChunks['assemble_steps']++;
+
+ // Do the next step
+ switch ($this->finalPackageChunks['assemble_steps']) {
+ case 1: // Sort the chunks array (the serial number shall act as a sorting key)
+ $this->sortChunksArray();
+ break;
+
+ case 2: // Prepare the assemble by removing last two indexes
+ $this->preparePackageAssmble();
+ break;
+
+ case 3: // Assemble all chunks back together to the original package
+ $this->assembleAllChunksToPackage();
+ break;
+
+ case 4: // Verify the raw data by hashing it again
+ $this->verifyRawPackageData();
+ break;
+
+ case 5: // Re-initialize handler to reset it to the old state
+ $this->initHandler();
+ break;
+
+ default: // Invalid step found
+ $this->debugOutput('CHUNK-HANDLER: Invalid step ' . $this->finalPackageChunks['assemble_steps'] . ' detected.');
+ break;
+ } // END - switch
+ }
+
+ /**
+ * Checks whether the raw package data has been assembled back together.
+ * This can be safely assumed when rawPackageData is not empty and the
+ * collection of all chunks is false (because initHandler() will reset it).
+ *
+ * @return $isRawPackageDataAvailable Whether raw package data is available
+ */
+ public function ifRawPackageDataIsAvailable () {
+ // Check it
+ $isRawPackageDataAvailable = ((!empty($this->rawPackageData)) && (!$this->ifUnassembledChunksAvailable()));
+
+ // Return it
+ return $isRawPackageDataAvailable;
+ }
+
+ /**
+ * Handles the finally assembled raw package data by feeding it into another
+ * stacker for further decoding/processing.
+ *
+ * @return void
+ */
+ public function handledAssembledRawPackageData () {
+ // Assert to make sure that there is raw package data available
+ assert($this->ifRawPackageDataIsAvailable());
+
+ // Then feed it into the next stacker
+ $this->getStackerInstance()->pushNamed(self::STACKER_NAME_ASSEMBLED_RAW_DATA, $this->rawPackageData);
+
+ // ... and reset it
+ $this->rawPackageData = '';
}
}
projects / hub.git / blobdiff