File Content: class-wp-http-encoding.php <?php /** * HTTP API: WP_Http_Encoding class * * @package WordPress * @subpackage HTTP * @since 4.4.0 */ /** * Core class used to implement deflate and gzip transfer encoding support for HTTP requests. * * Includes RFC 1950, RFC 1951, and RFC 1952. * * @since 2.8.0 */ class WP_Http_Encoding { /** * Compress raw string using the deflate format. * * Supports the RFC 1951 standard. * * @since 2.8.0 * * @static * * @param string $raw String to compress. * @param int $level Optional, default is 9. Compression level, 9 is highest. * @param string $supports Optional, not used. When implemented it will choose the right compression based on what the server supports. * @return string|false False on failure. */ public static function compress( $raw, $level = 9, $supports = null ) { return gzdeflate( $raw, $level ); } /** * Decompression of deflated string. * * Will attempt to decompress using the RFC 1950 standard, and if that fails * then the RFC 1951 standard deflate will be attempted. Finally, the RFC * 1952 standard gzip decode will be attempted. If all fail, then the * original compressed string will be returned. * * @since 2.8.0 * * @static * * @param string $compressed String to decompress. * @param int $length The optional length of the compressed data. * @return string|bool False on failure. */ public static function decompress( $compressed, $length = null ) { if ( empty($compressed) ) return $compressed; if ( false !== ( $decompressed = @gzinflate( $compressed ) ) ) return $decompressed; if ( false !== ( $decompressed = self::compatible_gzinflate( $compressed ) ) ) return $decompressed; if ( false !== ( $decompressed = @gzuncompress( $compressed ) ) ) return $decompressed; if ( function_exists('gzdecode') ) { $decompressed = @gzdecode( $compressed ); if ( false !== $decompressed ) return $decompressed; } return $compressed; } /** * Decompression of deflated string while staying compatible with the majority of servers. * * Certain Servers will return deflated data with headers which PHP's gzinflate() * function cannot handle out of the box. The following function has been created from * various snippets on the gzinflate() PHP documentation. * * Warning: Magic numbers within. Due to the potential different formats that the compressed * data may be returned in, some "magic offsets" are needed to ensure proper decompression * takes place. For a simple progmatic way to determine the magic offset in use, see: * https://core.trac.wordpress.org/ticket/18273 * * @since 2.8.1 * @link https://core.trac.wordpress.org/ticket/18273 * @link https://secure.php.net/manual/en/function.gzinflate.php#70875 * @link https://secure.php.net/manual/en/function.gzinflate.php#77336 * * @static * * @param string $gzData String to decompress. * @return string|bool False on failure. */ public static function compatible_gzinflate($gzData) { // Compressed data might contain a full header, if so strip it for gzinflate(). if ( substr($gzData, 0, 3) == "\x1f\x8b\x08" ) { $i = 10; $flg = ord( substr($gzData, 3, 1) ); if ( $flg > 0 ) { if ( $flg & 4 ) { list($xlen) = unpack('v', substr($gzData, $i, 2) ); $i = $i + 2 + $xlen; } if ( $flg & 8 ) $i = strpos($gzData, "\0", $i) + 1; if ( $flg & 16 ) $i = strpos($gzData, "\0", $i) + 1; if ( $flg & 2 ) $i = $i + 2; } $decompressed = @gzinflate( substr($gzData, $i, -8) ); if ( false !== $decompressed ) return $decompressed; } // Compressed data from java.util.zip.Deflater amongst others. $decompressed = @gzinflate( substr($gzData, 2) ); if ( false !== $decompressed ) return $decompressed; return false; } /** * What encoding types to accept and their priority values. * * @since 2.8.0 * * @static * * @param string $url * @param array $args * @return string Types of encoding to accept. */ public static function accept_encoding( $url, $args ) { $type = array(); $compression_enabled = self::is_available(); if ( ! $args['decompress'] ) // Decompression specifically disabled. $compression_enabled = false; elseif ( $args['stream'] ) // Disable when streaming to file. $compression_enabled = false; elseif ( isset( $args['limit_response_size'] ) ) // If only partial content is being requested, we won't be able to decompress it. $compression_enabled = false; if ( $compression_enabled ) { if ( function_exists( 'gzinflate' ) ) $type[] = 'deflate;q=1.0'; if ( function_exists( 'gzuncompress' ) ) $type[] = 'compress;q=0.5'; if ( function_exists( 'gzdecode' ) ) $type[] = 'gzip;q=0.5'; } /** * Filters the allowed encoding types. * * @since 3.6.0 * * @param array $type Encoding types allowed. Accepts 'gzinflate', * 'gzuncompress', 'gzdecode'. * @param string $url URL of the HTTP request. * @param array $args HTTP request arguments. */ $type = apply_filters( 'wp_http_accept_encoding', $type, $url, $args ); return implode(', ', $type); } /** * What encoding the content used when it was compressed to send in the headers. * * @since 2.8.0 * * @static * * @return string Content-Encoding string to send in the header. */ public static function content_encoding() { return 'deflate'; } /** * Whether the content be decoded based on the headers. * * @since 2.8.0 * * @static * * @param array|string $headers All of the available headers. * @return bool */ public static function should_decode($headers) { if ( is_array( $headers ) ) { if ( array_key_exists('content-encoding', $headers) && ! empty( $headers['content-encoding'] ) ) return true; } elseif ( is_string( $headers ) ) { return ( stripos($headers, 'content-encoding:') !== false ); } return false; } /** * Whether decompression and compression are supported by the PHP version. * * Each function is tested instead of checking for the zlib extension, to * ensure that the functions all exist in the PHP version and aren't * disabled. * * @since 2.8.0 * * @static * * @return bool */ public static function is_available() { return ( function_exists('gzuncompress') || function_exists('gzdeflate') || function_exists('gzinflate') ); } } Submit