Dave Jarvis' Repositories
git clone https://repo.autonoma.ca/repo/keenwrite.git
Separates range parsing into own function
| Author | DaveJarvis <email> |
|---|---|
| Date | 2023-11-11 14:20:48 GMT-0800 |
| Commit | 32d4eef4862f184b864df8b6af2afcc32b63aae9 |
| Parent | 98a9107 |
| Delta | 41 lines added, 30 lines removed, 11-line increase |
www/downloads/counter.php
| $size = $size === false || empty( $size ) ? 0 : $size; | ||
| $content_type = mime_content_type( $filename ); | ||
| - $content_length = $size; | ||
| - $seek_start = 0; | ||
| + list( $seek_start, $content_length ) = parse_range( $size ); | ||
| // Added by PHP, removed by us. | ||
| header_remove( 'x-powered-by' ); | ||
| + | ||
| + // HTTP/1.1 clients must treat invalid date formats, especially 0, as past. | ||
| + header( 'Expires: 0' ); | ||
| + | ||
| + // Prevent local caching. | ||
| + header( 'Cache-Control: public, must-revalidate, post-check=0, pre-check=0' ); | ||
| + | ||
| + // No response message portion may be cached (e.g., by a proxy server). | ||
| + header( 'Cache-Control: private', false ); | ||
| + | ||
| + // Force the browser to download, rather than displaying the file inline. | ||
| + header( "Content-Disposition: attachment; filename=\"$filename\"" ); | ||
| + header( 'Accept-Ranges: bytes' ); | ||
| + header( "Content-Length: $content_length" ); | ||
| + header( "Content-Type: $content_type" ); | ||
| + | ||
| + // Honour HTTP HEAD requests. | ||
| + return $_SERVER['REQUEST_METHOD'] === 'HEAD' | ||
| + ? false | ||
| + : transmit( $filename, $seek_start, $size ); | ||
| + } | ||
| + | ||
| + /** | ||
| + * Parses the HTTP range request header, provided one was sent by the | ||
| + * client. This provides download resume functionality. | ||
| + * | ||
| + * @param int $size The total file size (as stored on disk). | ||
| + * | ||
| + * @return int The starting offset for resuming the download, or 0 to | ||
| + * download the entire file (i.e., no offset could be parsed). | ||
| + */ | ||
| + function parse_range( $size ) { | ||
| + // By default, start transmitting at the beginning of the file. | ||
| + $seek_start = 0; | ||
| + $content_length = $size; | ||
| // Check if a range is sent by browser or download manager. | ||
 | ||
| header( "Content-Range: bytes */$size" ); | ||
| - // Return early because the range is invalid. | ||
| - return false; | ||
| + // Terminate because the range is invalid. | ||
| + exit; | ||
| } | ||
| // Multiple ranges could be specified, but only serve the first range. | ||
| $seek_start = $matches[ 1 ] + 0; | ||
| - | ||
| - if( isset( $matches[ 2 ] ) ) { | ||
| - $seek_end = $matches[ 2 ] + 0; | ||
| - } | ||
| - else { | ||
| - $seek_end = $size - 1; | ||
| - } | ||
| + $seek_end = isset( $matches[ 2 ] ) ? $matches[ 2 ] + 0 : $size - 1; | ||
| $range_bytes = $seek_start . '-' . $seek_end . '/' . $size; | ||
| $content_length = $seek_end - $seek_start + 1; | ||
| header( 'HTTP/1.1 206 Partial Content' ); | ||
| header( "Content-Range: bytes $range_bytes" ); | ||
| } | ||
| - | ||
| - // HTTP/1.1 clients must treat invalid date formats, especially 0, as past. | ||
| - header( 'Expires: 0' ); | ||
| - | ||
| - // Prevent local caching. | ||
| - header( 'Cache-Control: public, must-revalidate, post-check=0, pre-check=0' ); | ||
| - | ||
| - // No response message portion may be cached (e.g., by a proxy server). | ||
| - header( 'Cache-Control: private', false ); | ||
| - | ||
| - // Force the browser to download, rather than displaying the file inline. | ||
| - header( "Content-Disposition: attachment; filename=\"$filename\"" ); | ||
| - header( 'Accept-Ranges: bytes' ); | ||
| - header( "Content-Length: $content_length" ); | ||
| - header( "Content-Type: $content_type" ); | ||
| - // Honour HTTP HEAD requests. | ||
| - return $_SERVER['REQUEST_METHOD'] === 'HEAD' | ||
| - ? false | ||
| - : transmit( $filename, $seek_start, $size ); | ||
| + return array( $seek_start, $content_length ); | ||
| } | ||
| + | ||
| /** | ||
| * Transmits a file from the server to the client. | ||