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Diffstat (limited to 'min/lib/HTTP/Encoder.php')
-rw-r--r-- | min/lib/HTTP/Encoder.php | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/min/lib/HTTP/Encoder.php b/min/lib/HTTP/Encoder.php new file mode 100644 index 0000000..05ca552 --- /dev/null +++ b/min/lib/HTTP/Encoder.php @@ -0,0 +1,326 @@ +<?php +/** + * Class HTTP_Encoder + * @package Minify + * @subpackage HTTP + */ + +/** + * Encode and send gzipped/deflated content + * + * The "Vary: Accept-Encoding" header is sent. If the client allows encoding, + * Content-Encoding and Content-Length are added. + * + * <code> + * // Send a CSS file, compressed if possible + * $he = new HTTP_Encoder(array( + * 'content' => file_get_contents($cssFile) + * ,'type' => 'text/css' + * )); + * $he->encode(); + * $he->sendAll(); + * </code> + * + * <code> + * // Shortcut to encoding output + * header('Content-Type: text/css'); // needed if not HTML + * HTTP_Encoder::output($css); + * </code> + * + * <code> + * // Just sniff for the accepted encoding + * $encoding = HTTP_Encoder::getAcceptedEncoding(); + * </code> + * + * For more control over headers, use getHeaders() and getData() and send your + * own output. + * + * Note: If you don't need header mgmt, use PHP's native gzencode, gzdeflate, + * and gzcompress functions for gzip, deflate, and compress-encoding + * respectively. + * + * @package Minify + * @subpackage HTTP + * @author Stephen Clay <steve@mrclay.org> + */ +class HTTP_Encoder { + + /** + * Should the encoder allow HTTP encoding to IE6? + * + * If you have many IE6 users and the bandwidth savings is worth troubling + * some of them, set this to true. + * + * By default, encoding is only offered to IE7+. When this is true, + * getAcceptedEncoding() will return an encoding for IE6 if its user agent + * string contains "SV1". This has been documented in many places as "safe", + * but there seem to be remaining, intermittent encoding bugs in patched + * IE6 on the wild web. + * + * @var bool + */ + public static $encodeToIe6 = false; + + + /** + * Default compression level for zlib operations + * + * This level is used if encode() is not given a $compressionLevel + * + * @var int + */ + public static $compressionLevel = 6; + + + /** + * Get an HTTP Encoder object + * + * @param array $spec options + * + * 'content': (string required) content to be encoded + * + * 'type': (string) if set, the Content-Type header will have this value. + * + * 'method: (string) only set this if you are forcing a particular encoding + * method. If not set, the best method will be chosen by getAcceptedEncoding() + * The available methods are 'gzip', 'deflate', 'compress', and '' (no + * encoding) + * + * @return null + */ + public function __construct($spec) + { + $this->_content = $spec['content']; + $this->_headers['Content-Length'] = (string)strlen($this->_content); + if (isset($spec['type'])) { + $this->_headers['Content-Type'] = $spec['type']; + } + if (isset($spec['method']) + && in_array($spec['method'], array('gzip', 'deflate', 'compress', ''))) + { + $this->_encodeMethod = array($spec['method'], $spec['method']); + } else { + $this->_encodeMethod = self::getAcceptedEncoding(); + } + } + + /** + * Get content in current form + * + * Call after encode() for encoded content. + * + * return string + */ + public function getContent() + { + return $this->_content; + } + + /** + * Get array of output headers to be sent + * + * E.g. + * <code> + * array( + * 'Content-Length' => '615' + * ,'Content-Encoding' => 'x-gzip' + * ,'Vary' => 'Accept-Encoding' + * ) + * </code> + * + * @return array + */ + public function getHeaders() + { + return $this->_headers; + } + + /** + * Send output headers + * + * You must call this before headers are sent and it probably cannot be + * used in conjunction with zlib output buffering / mod_gzip. Errors are + * not handled purposefully. + * + * @see getHeaders() + * + * @return null + */ + public function sendHeaders() + { + foreach ($this->_headers as $name => $val) { + header($name . ': ' . $val); + } + } + + /** + * Send output headers and content + * + * A shortcut for sendHeaders() and echo getContent() + * + * You must call this before headers are sent and it probably cannot be + * used in conjunction with zlib output buffering / mod_gzip. Errors are + * not handled purposefully. + * + * @return null + */ + public function sendAll() + { + $this->sendHeaders(); + echo $this->_content; + } + + /** + * Determine the client's best encoding method from the HTTP Accept-Encoding + * header. + * + * If no Accept-Encoding header is set, or the browser is IE before v6 SP2, + * this will return ('', ''), the "identity" encoding. + * + * A syntax-aware scan is done of the Accept-Encoding, so the method must + * be non 0. The methods are favored in order of gzip, deflate, then + * compress. Deflate is always smallest and generally faster, but is + * rarely sent by servers, so client support could be buggier. + * + * @param bool $allowCompress allow the older compress encoding + * + * @param bool $allowDeflate allow the more recent deflate encoding + * + * @return array two values, 1st is the actual encoding method, 2nd is the + * alias of that method to use in the Content-Encoding header (some browsers + * call gzip "x-gzip" etc.) + */ + public static function getAcceptedEncoding($allowCompress = true, $allowDeflate = true) + { + // @link http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html + + if (! isset($_SERVER['HTTP_ACCEPT_ENCODING']) + || self::_isBuggyIe()) + { + return array('', ''); + } + $ae = $_SERVER['HTTP_ACCEPT_ENCODING']; + // gzip checks (quick) + if (0 === strpos($ae, 'gzip,') // most browsers + || 0 === strpos($ae, 'deflate, gzip,') // opera + ) { + return array('gzip', 'gzip'); + } + // gzip checks (slow) + if (preg_match( + '@(?:^|,)\\s*((?:x-)?gzip)\\s*(?:$|,|;\\s*q=(?:0\\.|1))@' + ,$ae + ,$m)) { + return array('gzip', $m[1]); + } + if ($allowDeflate) { + // deflate checks + $aeRev = strrev($ae); + if (0 === strpos($aeRev, 'etalfed ,') // ie, webkit + || 0 === strpos($aeRev, 'etalfed,') // gecko + || 0 === strpos($ae, 'deflate,') // opera + // slow parsing + || preg_match( + '@(?:^|,)\\s*deflate\\s*(?:$|,|;\\s*q=(?:0\\.|1))@', $ae)) { + return array('deflate', 'deflate'); + } + } + if ($allowCompress && preg_match( + '@(?:^|,)\\s*((?:x-)?compress)\\s*(?:$|,|;\\s*q=(?:0\\.|1))@' + ,$ae + ,$m)) { + return array('compress', $m[1]); + } + return array('', ''); + } + + /** + * Encode (compress) the content + * + * If the encode method is '' (none) or compression level is 0, or the 'zlib' + * extension isn't loaded, we return false. + * + * Then the appropriate gz_* function is called to compress the content. If + * this fails, false is returned. + * + * The header "Vary: Accept-Encoding" is added. If encoding is successful, + * the Content-Length header is updated, and Content-Encoding is also added. + * + * @param int $compressionLevel given to zlib functions. If not given, the + * class default will be used. + * + * @return bool success true if the content was actually compressed + */ + public function encode($compressionLevel = null) + { + $this->_headers['Vary'] = 'Accept-Encoding'; + if (null === $compressionLevel) { + $compressionLevel = self::$compressionLevel; + } + if ('' === $this->_encodeMethod[0] + || ($compressionLevel == 0) + || !extension_loaded('zlib')) + { + return false; + } + if ($this->_encodeMethod[0] === 'deflate') { + $encoded = gzdeflate($this->_content, $compressionLevel); + } elseif ($this->_encodeMethod[0] === 'gzip') { + $encoded = gzencode($this->_content, $compressionLevel); + } else { + $encoded = gzcompress($this->_content, $compressionLevel); + } + if (false === $encoded) { + return false; + } + $this->_headers['Content-Length'] = strlen($encoded); + $this->_headers['Content-Encoding'] = $this->_encodeMethod[1]; + $this->_content = $encoded; + return true; + } + + /** + * Encode and send appropriate headers and content + * + * This is a convenience method for common use of the class + * + * @param string $content + * + * @param int $compressionLevel given to zlib functions. If not given, the + * class default will be used. + * + * @return bool success true if the content was actually compressed + */ + public static function output($content, $compressionLevel = null) + { + if (null === $compressionLevel) { + $compressionLevel = self::$compressionLevel; + } + $he = new HTTP_Encoder(array('content' => $content)); + $ret = $he->encode($compressionLevel); + $he->sendAll(); + return $ret; + } + + protected $_content = ''; + protected $_headers = array(); + protected $_encodeMethod = array('', ''); + + /** + * Is the browser an IE version earlier than 6 SP2? + */ + protected static function _isBuggyIe() + { + $ua = $_SERVER['HTTP_USER_AGENT']; + // quick escape for non-IEs + if (0 !== strpos($ua, 'Mozilla/4.0 (compatible; MSIE ') + || false !== strpos($ua, 'Opera')) { + return false; + } + // no regex = faaast + $version = (float)substr($ua, 30); + return self::$encodeToIe6 + ? ($version < 6 || ($version == 6 && false === strpos($ua, 'SV1'))) + : ($version < 7); + } +} |