diff options
Diffstat (limited to 'min/lib/HTTP')
-rw-r--r-- | min/lib/HTTP/ConditionalGet.php | 348 | ||||
-rw-r--r-- | min/lib/HTTP/Encoder.php | 326 |
2 files changed, 674 insertions, 0 deletions
diff --git a/min/lib/HTTP/ConditionalGet.php b/min/lib/HTTP/ConditionalGet.php new file mode 100644 index 0000000..823db05 --- /dev/null +++ b/min/lib/HTTP/ConditionalGet.php @@ -0,0 +1,348 @@ +<?php +/** + * Class HTTP_ConditionalGet + * @package Minify + * @subpackage HTTP + */ + +/** + * Implement conditional GET via a timestamp or hash of content + * + * E.g. Content from DB with update time: + * <code> + * list($updateTime, $content) = getDbUpdateAndContent(); + * $cg = new HTTP_ConditionalGet(array( + * 'lastModifiedTime' => $updateTime + * ,'isPublic' => true + * )); + * $cg->sendHeaders(); + * if ($cg->cacheIsValid) { + * exit(); + * } + * echo $content; + * </code> + * + * E.g. Shortcut for the above + * <code> + * HTTP_ConditionalGet::check($updateTime, true); // exits if client has cache + * echo $content; + * </code> + * + * E.g. Content from DB with no update time: + * <code> + * $content = getContentFromDB(); + * $cg = new HTTP_ConditionalGet(array( + * 'contentHash' => md5($content) + * )); + * $cg->sendHeaders(); + * if ($cg->cacheIsValid) { + * exit(); + * } + * echo $content; + * </code> + * + * E.g. Static content with some static includes: + * <code> + * // before content + * $cg = new HTTP_ConditionalGet(array( + * 'lastUpdateTime' => max( + * filemtime(__FILE__) + * ,filemtime('/path/to/header.inc') + * ,filemtime('/path/to/footer.inc') + * ) + * )); + * $cg->sendHeaders(); + * if ($cg->cacheIsValid) { + * exit(); + * } + * </code> + * @package Minify + * @subpackage HTTP + * @author Stephen Clay <steve@mrclay.org> + */ +class HTTP_ConditionalGet { + + /** + * Does the client have a valid copy of the requested resource? + * + * You'll want to check this after instantiating the object. If true, do + * not send content, just call sendHeaders() if you haven't already. + * + * @var bool + */ + public $cacheIsValid = null; + + /** + * @param array $spec options + * + * 'isPublic': (bool) if true, the Cache-Control header will contain + * "public", allowing proxies to cache the content. Otherwise "private" will + * be sent, allowing only browser caching. (default false) + * + * 'lastModifiedTime': (int) if given, both ETag AND Last-Modified headers + * will be sent with content. This is recommended. + * + * 'encoding': (string) if set, the header "Vary: Accept-Encoding" will + * always be sent and a truncated version of the encoding will be appended + * to the ETag. E.g. "pub123456;gz". This will also trigger a more lenient + * checking of the client's If-None-Match header, as the encoding portion of + * the ETag will be stripped before comparison. + * + * 'contentHash': (string) if given, only the ETag header can be sent with + * content (only HTTP1.1 clients can conditionally GET). The given string + * should be short with no quote characters and always change when the + * resource changes (recommend md5()). This is not needed/used if + * lastModifiedTime is given. + * + * 'eTag': (string) if given, this will be used as the ETag header rather + * than values based on lastModifiedTime or contentHash. Also the encoding + * string will not be appended to the given value as described above. + * + * 'invalidate': (bool) if true, the client cache will be considered invalid + * without testing. Effectively this disables conditional GET. + * (default false) + * + * 'maxAge': (int) if given, this will set the Cache-Control max-age in + * seconds, and also set the Expires header to the equivalent GMT date. + * After the max-age period has passed, the browser will again send a + * conditional GET to revalidate its cache. + * + * @return null + */ + public function __construct($spec) + { + $scope = (isset($spec['isPublic']) && $spec['isPublic']) + ? 'public' + : 'private'; + $maxAge = 0; + // backwards compatibility (can be removed later) + if (isset($spec['setExpires']) + && is_numeric($spec['setExpires']) + && ! isset($spec['maxAge'])) { + $spec['maxAge'] = $spec['setExpires'] - $_SERVER['REQUEST_TIME']; + } + if (isset($spec['maxAge'])) { + $maxAge = $spec['maxAge']; + $this->_headers['Expires'] = self::gmtDate( + $_SERVER['REQUEST_TIME'] + $spec['maxAge'] + ); + } + $etagAppend = ''; + if (isset($spec['encoding'])) { + $this->_stripEtag = true; + $this->_headers['Vary'] = 'Accept-Encoding'; + if ('' !== $spec['encoding']) { + if (0 === strpos($spec['encoding'], 'x-')) { + $spec['encoding'] = substr($spec['encoding'], 2); + } + $etagAppend = ';' . substr($spec['encoding'], 0, 2); + } + } + if (isset($spec['lastModifiedTime'])) { + $this->_setLastModified($spec['lastModifiedTime']); + if (isset($spec['eTag'])) { // Use it + $this->_setEtag($spec['eTag'], $scope); + } else { // base both headers on time + $this->_setEtag($spec['lastModifiedTime'] . $etagAppend, $scope); + } + } elseif (isset($spec['eTag'])) { // Use it + $this->_setEtag($spec['eTag'], $scope); + } elseif (isset($spec['contentHash'])) { // Use the hash as the ETag + $this->_setEtag($spec['contentHash'] . $etagAppend, $scope); + } + $this->_headers['Cache-Control'] = "max-age={$maxAge}, {$scope}"; + // invalidate cache if disabled, otherwise check + $this->cacheIsValid = (isset($spec['invalidate']) && $spec['invalidate']) + ? false + : $this->_isCacheValid(); + } + + /** + * Get array of output headers to be sent + * + * In the case of 304 responses, this array will only contain the response + * code header: array('_responseCode' => 'HTTP/1.0 304 Not Modified') + * + * Otherwise something like: + * <code> + * array( + * 'Cache-Control' => 'max-age=0, public' + * ,'ETag' => '"foobar"' + * ) + * </code> + * + * @return array + */ + public function getHeaders() + { + return $this->_headers; + } + + /** + * Set the Content-Length header in bytes + * + * With most PHP configs, as long as you don't flush() output, this method + * is not needed and PHP will buffer all output and set Content-Length for + * you. Otherwise you'll want to call this to let the client know up front. + * + * @param int $bytes + * + * @return int copy of input $bytes + */ + public function setContentLength($bytes) + { + return $this->_headers['Content-Length'] = $bytes; + } + + /** + * Send headers + * + * @see getHeaders() + * + * Note this doesn't "clear" the headers. Calling sendHeaders() will + * call header() again (but probably have not effect) and getHeaders() will + * still return the headers. + * + * @return null + */ + public function sendHeaders() + { + $headers = $this->_headers; + if (array_key_exists('_responseCode', $headers)) { + header($headers['_responseCode']); + unset($headers['_responseCode']); + } + foreach ($headers as $name => $val) { + header($name . ': ' . $val); + } + } + + /** + * Exit if the client's cache is valid for this resource + * + * This is a convenience method for common use of the class + * + * @param int $lastModifiedTime if given, both ETag AND Last-Modified headers + * will be sent with content. This is recommended. + * + * @param bool $isPublic (default false) if true, the Cache-Control header + * will contain "public", allowing proxies to cache the content. Otherwise + * "private" will be sent, allowing only browser caching. + * + * @param array $options (default empty) additional options for constructor + * + * @return null + */ + public static function check($lastModifiedTime = null, $isPublic = false, $options = array()) + { + if (null !== $lastModifiedTime) { + $options['lastModifiedTime'] = (int)$lastModifiedTime; + } + $options['isPublic'] = (bool)$isPublic; + $cg = new HTTP_ConditionalGet($options); + $cg->sendHeaders(); + if ($cg->cacheIsValid) { + exit(); + } + } + + + /** + * Get a GMT formatted date for use in HTTP headers + * + * <code> + * header('Expires: ' . HTTP_ConditionalGet::gmtdate($time)); + * </code> + * + * @param int $time unix timestamp + * + * @return string + */ + public static function gmtDate($time) + { + return gmdate('D, d M Y H:i:s \G\M\T', $time); + } + + protected $_headers = array(); + protected $_lmTime = null; + protected $_etag = null; + protected $_stripEtag = false; + + protected function _setEtag($hash, $scope) + { + $this->_etag = '"' . substr($scope, 0, 3) . $hash . '"'; + $this->_headers['ETag'] = $this->_etag; + } + + protected function _setLastModified($time) + { + $this->_lmTime = (int)$time; + $this->_headers['Last-Modified'] = self::gmtDate($time); + } + + /** + * Determine validity of client cache and queue 304 header if valid + */ + protected function _isCacheValid() + { + if (null === $this->_etag) { + // lmTime is copied to ETag, so this condition implies that the + // server sent neither ETag nor Last-Modified, so the client can't + // possibly has a valid cache. + return false; + } + $isValid = ($this->resourceMatchedEtag() || $this->resourceNotModified()); + if ($isValid) { + $this->_headers['_responseCode'] = 'HTTP/1.0 304 Not Modified'; + } + return $isValid; + } + + protected function resourceMatchedEtag() + { + if (!isset($_SERVER['HTTP_IF_NONE_MATCH'])) { + return false; + } + $clientEtagList = get_magic_quotes_gpc() + ? stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) + : $_SERVER['HTTP_IF_NONE_MATCH']; + $clientEtags = explode(',', $clientEtagList); + + $compareTo = $this->normalizeEtag($this->_etag); + foreach ($clientEtags as $clientEtag) { + if ($this->normalizeEtag($clientEtag) === $compareTo) { + // respond with the client's matched ETag, even if it's not what + // we would've sent by default + $this->_headers['ETag'] = trim($clientEtag); + return true; + } + } + return false; + } + + protected function normalizeEtag($etag) { + $etag = trim($etag); + return $this->_stripEtag + ? preg_replace('/;\\w\\w"$/', '"', $etag) + : $etag; + } + + protected function resourceNotModified() + { + if (!isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) { + return false; + } + $ifModifiedSince = $_SERVER['HTTP_IF_MODIFIED_SINCE']; + if (false !== ($semicolon = strrpos($ifModifiedSince, ';'))) { + // IE has tacked on extra data to this header, strip it + $ifModifiedSince = substr($ifModifiedSince, 0, $semicolon); + } + if ($ifModifiedSince == self::gmtDate($this->_lmTime)) { + // Apache 2.2's behavior. If there was no ETag match, send the + // non-encoded version of the ETag value. + $this->_headers['ETag'] = $this->normalizeEtag($this->_etag); + return true; + } + return false; + } +} 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); + } +} |