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<?php |
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/* |
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* This file is part of the ManageWP Worker plugin. |
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* |
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* (c) ManageWP LLC <contact@managewp.com> |
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* |
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* For the full copyright and license information, please view the LICENSE |
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* file that was distributed with this source code. |
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*/ |
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|
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class MWP_IncrementalBackup_HashComputer |
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{ |
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|
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// 100kb default value |
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private $maxChunkByteSize = 102400; |
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|
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/** |
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* @param int $maxChunkByteSize |
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*/ |
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public function setMaxChunkByteSize($maxChunkByteSize) |
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{ |
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$this->maxChunkByteSize = $maxChunkByteSize; |
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} |
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|
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/** |
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* @return int |
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*/ |
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public function getMaxChunkByteSize() |
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{ |
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return $this->maxChunkByteSize; |
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} |
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|
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/** |
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* Compute a full md5 file hash or compute a partial hash if $limit is present. |
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* Returns null on failure. |
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* |
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* @param string $realPath |
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* @param int $offset in bytes |
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* @param int $limit in bytes |
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* @param boolean $forcePartialHashing |
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* |
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* @return null|string |
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*/ |
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public function computeMd5Hash($realPath, $offset = 0, $limit = 0, $forcePartialHashing = false) |
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{ |
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if ($limit === 0 && $offset === 0 && !$forcePartialHashing) { |
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// md5_file is always faster if we don't chunk the file |
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$hash = md5_file($realPath); |
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|
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return $hash !== false ? $hash : null; |
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} |
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|
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$ctx = hash_init('md5'); |
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if (!$ctx) { |
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// Fail to initialize file hashing |
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return null; |
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} |
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|
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// Calculate limit from file size and offset |
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if ($limit === 0) { |
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$limit = filesize($realPath) - $offset; |
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} |
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|
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$fh = @fopen($realPath, "rb"); |
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if ($fh === false) { |
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// Failed opening file, cleanup hash context |
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hash_final($ctx); |
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|
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return null; |
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} |
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|
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fseek($fh, $offset); |
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|
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while ($limit > 0) { |
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// Limit chunk size to either our remaining chunk or max chunk size |
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$chunkSize = $limit < $this->maxChunkByteSize ? $limit : $this->maxChunkByteSize; |
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$limit -= $chunkSize; |
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|
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$chunk = fread($fh, $chunkSize); |
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hash_update($ctx, $chunk); |
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} |
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|
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fclose($fh); |
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|
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return hash_final($ctx); |
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} |
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|
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/** |
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* Run md5sum process and return file hash, or null in case of error |
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* |
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* @param $realPath |
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* |
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* @return string|null |
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*/ |
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public function computeUnixMd5Sum($realPath) |
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{ |
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try { |
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$processBuilder = Symfony_Process_ProcessBuilder::create() |
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->setPrefix('md5sum') |
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->add($realPath); |
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|
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if (!mwp_is_shell_available()) { |
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throw new MWP_Worker_Exception(MWP_Worker_Exception::SHELL_NOT_AVAILABLE, "Shell is not available"); |
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} |
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|
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$process = $processBuilder->getProcess(); |
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$process->run(); |
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|
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if (!$process->isSuccessful()) { |
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throw new Symfony_Process_Exception_ProcessFailedException($process); |
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} |
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|
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// Output is in the format of "md5hash filename" |
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$output = trim($process->getOutput()); |
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$parts = explode(' ', $output); |
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|
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// Return only the first part of the output |
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return trim($parts[0]); |
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} catch (Symfony_Process_Exception_ProcessFailedException $e) { |
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mwp_logger()->error('MD5 command line sum failed', array( |
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'process' => $e->getProcess(), |
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)); |
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} catch (Exception $e) { |
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mwp_logger()->error('MD5 command line sum failed', array( |
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'exception' => $e, |
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)); |
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} |
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|
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return null; |
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} |
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} |
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|
