Downloader.php
91 lines
| 1 | <?php |
| 2 | |
| 3 | namespace JetBackup\Downloader; |
| 4 | |
| 5 | use JetBackup\Exception\DownloaderException; |
| 6 | use JetBackup\Factory; |
| 7 | use JetBackup\JetBackup; |
| 8 | |
| 9 | if (!defined( '__JETBACKUP__')) die('Direct access is not allowed'); |
| 10 | |
| 11 | class Downloader { |
| 12 | |
| 13 | const DEFAULT_CHUNK = 4096; // 4k |
| 14 | |
| 15 | private ?string $_filename; |
| 16 | private string $_source; |
| 17 | |
| 18 | /** |
| 19 | * @param string $source |
| 20 | * @param string|null $filename |
| 21 | */ |
| 22 | public function __construct(string $source, ?string $filename=null) { |
| 23 | $this->_source = $source; |
| 24 | $this->_filename = $filename; |
| 25 | } |
| 26 | |
| 27 | /** |
| 28 | * @return \stdClass |
| 29 | */ |
| 30 | private static function _getRange($filesize):object { |
| 31 | $output = new \stdClass(); |
| 32 | $output->start = 0; |
| 33 | $output->end = $filesize-1; |
| 34 | |
| 35 | if ( |
| 36 | !isset($_SERVER['HTTP_RANGE']) || |
| 37 | !preg_match('/bytes=(\d+)-(\d*)/', $_SERVER['HTTP_RANGE'], $matches) |
| 38 | ) return $output; |
| 39 | |
| 40 | $output->start = (int) $matches[1]; |
| 41 | if (!empty($matches[2])) $output->end = (int) $matches[2]; |
| 42 | |
| 43 | return $output; |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * @param int $chunk |
| 48 | * |
| 49 | * @return void |
| 50 | * @throws DownloaderException |
| 51 | */ |
| 52 | public function download(int $chunk=self::DEFAULT_CHUNK):void { |
| 53 | |
| 54 | if( !$this->_source || !file_exists($this->_source) || is_dir($this->_source)) |
| 55 | throw new DownloaderException('The provided download file not exists'); |
| 56 | |
| 57 | if (!str_starts_with(trim($this->_source), trim(Factory::getLocations()->getDataDir()))) { |
| 58 | throw new DownloaderException('Invalid download source path'); |
| 59 | } |
| 60 | |
| 61 | if(!($fd = fopen($this->_source, 'rb'))) |
| 62 | throw new DownloaderException('Unable to open download file'); |
| 63 | |
| 64 | if(!$this->_filename) $this->_filename = basename($this->_source); |
| 65 | |
| 66 | $filesize = filesize($this->_source); |
| 67 | $range = self::_getRange($filesize); |
| 68 | |
| 69 | // gzip compression may corrupt binary data |
| 70 | if (function_exists('apache_setenv')) @apache_setenv('no-gzip', 1); |
| 71 | @ini_set('zlib.output_compression', 'Off'); |
| 72 | while (ob_get_level()) @ob_end_clean(); |
| 73 | flush(); |
| 74 | |
| 75 | header("Content-Type: application/octet-stream"); |
| 76 | header("Content-Disposition: attachment; filename=\"{$this->_filename}\""); |
| 77 | header("Accept-Ranges: bytes"); |
| 78 | header("Content-Length: " . ($range->end - $range->start + 1)); |
| 79 | header("Content-Range: bytes $range->start-$range->end/".$filesize); |
| 80 | |
| 81 | if($range->start > 0) fseek($fd, $range->start); |
| 82 | |
| 83 | while (!feof($fd) && ($pos = ftell($fd)) <= $range->end) { |
| 84 | echo fread($fd, min($chunk, $range->end - $pos + 1)); |
| 85 | flush(); |
| 86 | } |
| 87 | |
| 88 | fclose($fd); |
| 89 | exit; |
| 90 | } |
| 91 | } |