| 1 |
<?php |
| 2 |
/** |
| 3 |
* Class HTTP_Encoder |
| 4 |
* @package Minify |
| 5 |
* @subpackage HTTP |
| 6 |
*/ |
| 7 |
|
| 8 |
/** |
| 9 |
* Encode and send gzipped/deflated content |
| 10 |
* |
| 11 |
* The "Vary: Accept-Encoding" header is sent. If the client allows encoding, |
| 12 |
* Content-Encoding and Content-Length are added. |
| 13 |
* |
| 14 |
* <code> |
| 15 |
* // Send a CSS file, compressed if possible |
| 16 |
* $he = new HTTP_Encoder(array( |
| 17 |
* 'content' => file_get_contents($cssFile) |
| 18 |
* ,'type' => 'text/css' |
| 19 |
* )); |
| 20 |
* $he->encode(); |
| 21 |
* $he->sendAll(); |
| 22 |
* </code> |
| 23 |
* |
| 24 |
* <code> |
| 25 |
* // Shortcut to encoding output |
| 26 |
* header('Content-Type: text/css'); // needed if not HTML |
| 27 |
* HTTP_Encoder::output($css); |
| 28 |
* </code> |
| 29 |
* |
| 30 |
* <code> |
| 31 |
* // Just sniff for the accepted encoding |
| 32 |
* $encoding = HTTP_Encoder::getAcceptedEncoding(); |
| 33 |
* </code> |
| 34 |
* |
| 35 |
* For more control over headers, use getHeaders() and getData() and send your |
| 36 |
* own output. |
| 37 |
* |
| 38 |
* Note: If you don't need header mgmt, use PHP's native gzencode, gzdeflate, |
| 39 |
* and gzcompress functions for gzip, deflate, and compress-encoding |
| 40 |
* respectively. |
| 41 |
* |
| 42 |
* @package Minify |
| 43 |
* @subpackage HTTP |
| 44 |
* @author Stephen Clay <[email protected]> |
| 45 |
*/ |
| 46 |
class HTTP_Encoder |
| 47 |
{ |
| 48 |
|
| 49 |
/** |
| 50 |
* Should the encoder allow HTTP encoding to IE6? |
| 51 |
* |
| 52 |
* If you have many IE6 users and the bandwidth savings is worth troubling |
| 53 |
* some of them, set this to true. |
| 54 |
* |
| 55 |
* By default, encoding is only offered to IE7+. When this is true, |
| 56 |
* getAcceptedEncoding() will return an encoding for IE6 if its user agent |
| 57 |
* string contains "SV1". This has been documented in many places as "safe", |
| 58 |
* but there seem to be remaining, intermittent encoding bugs in patched |
| 59 |
* IE6 on the wild web. |
| 60 |
* |
| 61 |
* @var bool |
| 62 |
*/ |
| 63 |
public static $encodeToIe6 = true; |
| 64 |
|
| 65 |
/** |
| 66 |
* Default compression level for zlib operations |
| 67 |
* |
| 68 |
* This level is used if encode() is not given a $compressionLevel |
| 69 |
* |
| 70 |
* @var int |
| 71 |
*/ |
| 72 |
public static $compressionLevel = 6; |
| 73 |
|
| 74 |
/** |
| 75 |
* Get an HTTP Encoder object |
| 76 |
* |
| 77 |
* @param array $spec options |
| 78 |
* |
| 79 |
* 'content': (string required) content to be encoded |
| 80 |
* |
| 81 |
* 'type': (string) if set, the Content-Type header will have this value. |
| 82 |
* |
| 83 |
* 'method: (string) only set this if you are forcing a particular encoding |
| 84 |
* method. If not set, the best method will be chosen by getAcceptedEncoding() |
| 85 |
* The available methods are 'gzip', 'deflate', 'compress', and '' (no |
| 86 |
* encoding) |
| 87 |
*/ |
| 88 |
public function __construct($spec) |
| 89 |
{ |
| 90 |
$this->_useMbStrlen = (function_exists('mb_strlen') |
| 91 |
&& (ini_get('mbstring.func_overload') !== '') |
| 92 |
&& ((int)ini_get('mbstring.func_overload') & 2)); |
| 93 |
$this->_content = $spec['content']; |
| 94 |
$this->_headers['Content-Length'] = $this->_useMbStrlen |
| 95 |
? (string)mb_strlen($this->_content, '8bit') |
| 96 |
: (string)strlen($this->_content); |
| 97 |
if (isset($spec['type'])) { |
| 98 |
$this->_headers['Content-Type'] = $spec['type']; |
| 99 |
} |
| 100 |
if (isset($spec['method']) |
| 101 |
&& in_array($spec['method'], array('gzip', 'deflate', 'compress', ''))) { |
| 102 |
$this->_encodeMethod = array($spec['method'], $spec['method']); |
| 103 |
} else { |
| 104 |
$this->_encodeMethod = self::getAcceptedEncoding(); |
| 105 |
} |
| 106 |
} |
| 107 |
|
| 108 |
/** |
| 109 |
* Get content in current form |
| 110 |
* |
| 111 |
* Call after encode() for encoded content. |
| 112 |
* |
| 113 |
* @return string |
| 114 |
*/ |
| 115 |
public function getContent() |
| 116 |
{ |
| 117 |
return $this->_content; |
| 118 |
} |
| 119 |
|
| 120 |
/** |
| 121 |
* Get array of output headers to be sent |
| 122 |
* |
| 123 |
* E.g. |
| 124 |
* <code> |
| 125 |
* array( |
| 126 |
* 'Content-Length' => '615' |
| 127 |
* ,'Content-Encoding' => 'x-gzip' |
| 128 |
* ,'Vary' => 'Accept-Encoding' |
| 129 |
* ) |
| 130 |
* </code> |
| 131 |
* |
| 132 |
* @return array |
| 133 |
*/ |
| 134 |
public function getHeaders() |
| 135 |
{ |
| 136 |
return $this->_headers; |
| 137 |
} |
| 138 |
|
| 139 |
/** |
| 140 |
* Send output headers |
| 141 |
* |
| 142 |
* You must call this before headers are sent and it probably cannot be |
| 143 |
* used in conjunction with zlib output buffering / mod_gzip. Errors are |
| 144 |
* not handled purposefully. |
| 145 |
* |
| 146 |
* @see getHeaders() |
| 147 |
*/ |
| 148 |
public function sendHeaders() |
| 149 |
{ |
| 150 |
foreach ($this->_headers as $name => $val) { |
| 151 |
header($name . ': ' . $val); |
| 152 |
} |
| 153 |
} |
| 154 |
|
| 155 |
/** |
| 156 |
* Send output headers and content |
| 157 |
* |
| 158 |
* A shortcut for sendHeaders() and echo getContent() |
| 159 |
* |
| 160 |
* You must call this before headers are sent and it probably cannot be |
| 161 |
* used in conjunction with zlib output buffering / mod_gzip. Errors are |
| 162 |
* not handled purposefully. |
| 163 |
*/ |
| 164 |
public function sendAll() |
| 165 |
{ |
| 166 |
$this->sendHeaders(); |
| 167 |
echo $this->_content; |
| 168 |
} |
| 169 |
|
| 170 |
/** |
| 171 |
* Determine the client's best encoding method from the HTTP Accept-Encoding |
| 172 |
* header. |
| 173 |
* |
| 174 |
* If no Accept-Encoding header is set, or the browser is IE before v6 SP2, |
| 175 |
* this will return ('', ''), the "identity" encoding. |
| 176 |
* |
| 177 |
* A syntax-aware scan is done of the Accept-Encoding, so the method must |
| 178 |
* be non 0. The methods are favored in order of gzip, deflate, then |
| 179 |
* compress. Deflate is always smallest and generally faster, but is |
| 180 |
* rarely sent by servers, so client support could be buggier. |
| 181 |
* |
| 182 |
* @param bool $allowCompress allow the older compress encoding |
| 183 |
* |
| 184 |
* @param bool $allowDeflate allow the more recent deflate encoding |
| 185 |
* |
| 186 |
* @return array two values, 1st is the actual encoding method, 2nd is the |
| 187 |
* alias of that method to use in the Content-Encoding header (some browsers |
| 188 |
* call gzip "x-gzip" etc.) |
| 189 |
*/ |
| 190 |
public static function getAcceptedEncoding($allowCompress = true, $allowDeflate = true) |
| 191 |
{ |
| 192 |
// @link http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html |
| 193 |
|
| 194 |
if (! isset($_SERVER['HTTP_ACCEPT_ENCODING']) |
| 195 |
|| self::isBuggyIe()) { |
| 196 |
return array('', ''); |
| 197 |
} |
| 198 |
$ae = $_SERVER['HTTP_ACCEPT_ENCODING']; |
| 199 |
// gzip checks (quick) |
| 200 |
if (0 === strpos($ae, 'gzip,') // most browsers |
| 201 |
|| 0 === strpos($ae, 'deflate, gzip,') // opera |
| 202 |
) { |
| 203 |
return array('gzip', 'gzip'); |
| 204 |
} |
| 205 |
// gzip checks (slow) |
| 206 |
if (preg_match( |
| 207 |
'@(?:^|,)\\s*((?:x-)?gzip)\\s*(?:$|,|;\\s*q=(?:0\\.|1))@', |
| 208 |
$ae, |
| 209 |
$m |
| 210 |
)) { |
| 211 |
return array('gzip', $m[1]); |
| 212 |
} |
| 213 |
if ($allowDeflate) { |
| 214 |
// deflate checks |
| 215 |
$aeRev = strrev($ae); |
| 216 |
if (0 === strpos($aeRev, 'etalfed ,') // ie, webkit |
| 217 |
|| 0 === strpos($aeRev, 'etalfed,') // gecko |
| 218 |
|| 0 === strpos($ae, 'deflate,') // opera |
| 219 |
// slow parsing |
| 220 |
|| preg_match( |
| 221 |
'@(?:^|,)\\s*deflate\\s*(?:$|,|;\\s*q=(?:0\\.|1))@', |
| 222 |
$ae |
| 223 |
)) { |
| 224 |
return array('deflate', 'deflate'); |
| 225 |
} |
| 226 |
} |
| 227 |
if ($allowCompress && preg_match( |
| 228 |
'@(?:^|,)\\s*((?:x-)?compress)\\s*(?:$|,|;\\s*q=(?:0\\.|1))@', |
| 229 |
$ae, |
| 230 |
$m |
| 231 |
)) { |
| 232 |
return array('compress', $m[1]); |
| 233 |
} |
| 234 |
|
| 235 |
return array('', ''); |
| 236 |
} |
| 237 |
|
| 238 |
/** |
| 239 |
* Encode (compress) the content |
| 240 |
* |
| 241 |
* If the encode method is '' (none) or compression level is 0, or the 'zlib' |
| 242 |
* extension isn't loaded, we return false. |
| 243 |
* |
| 244 |
* Then the appropriate gz_* function is called to compress the content. If |
| 245 |
* this fails, false is returned. |
| 246 |
* |
| 247 |
* The header "Vary: Accept-Encoding" is added. If encoding is successful, |
| 248 |
* the Content-Length header is updated, and Content-Encoding is also added. |
| 249 |
* |
| 250 |
* @param int $compressionLevel given to zlib functions. If not given, the |
| 251 |
* class default will be used. |
| 252 |
* |
| 253 |
* @return bool success true if the content was actually compressed |
| 254 |
*/ |
| 255 |
public function encode($compressionLevel = null) |
| 256 |
{ |
| 257 |
if (! self::isBuggyIe()) { |
| 258 |
$this->_headers['Vary'] = 'Accept-Encoding'; |
| 259 |
} |
| 260 |
if (null === $compressionLevel) { |
| 261 |
$compressionLevel = self::$compressionLevel; |
| 262 |
} |
| 263 |
if ('' === $this->_encodeMethod[0] |
| 264 |
|| ($compressionLevel == 0) |
| 265 |
|| !extension_loaded('zlib')) { |
| 266 |
return false; |
| 267 |
} |
| 268 |
if ($this->_encodeMethod[0] === 'deflate') { |
| 269 |
$encoded = gzdeflate($this->_content, $compressionLevel); |
| 270 |
} elseif ($this->_encodeMethod[0] === 'gzip') { |
| 271 |
$encoded = gzencode($this->_content, $compressionLevel); |
| 272 |
} else { |
| 273 |
$encoded = gzcompress($this->_content, $compressionLevel); |
| 274 |
} |
| 275 |
if (false === $encoded) { |
| 276 |
return false; |
| 277 |
} |
| 278 |
$this->_headers['Content-Length'] = $this->_useMbStrlen |
| 279 |
? (string)mb_strlen($encoded, '8bit') |
| 280 |
: (string)strlen($encoded); |
| 281 |
$this->_headers['Content-Encoding'] = $this->_encodeMethod[1]; |
| 282 |
$this->_content = $encoded; |
| 283 |
|
| 284 |
return true; |
| 285 |
} |
| 286 |
|
| 287 |
/** |
| 288 |
* Encode and send appropriate headers and content |
| 289 |
* |
| 290 |
* This is a convenience method for common use of the class |
| 291 |
* |
| 292 |
* @param string $content |
| 293 |
* |
| 294 |
* @param int $compressionLevel given to zlib functions. If not given, the |
| 295 |
* class default will be used. |
| 296 |
* |
| 297 |
* @return bool success true if the content was actually compressed |
| 298 |
*/ |
| 299 |
public static function output($content, $compressionLevel = null) |
| 300 |
{ |
| 301 |
if (null === $compressionLevel) { |
| 302 |
$compressionLevel = self::$compressionLevel; |
| 303 |
} |
| 304 |
$he = new HTTP_Encoder(array('content' => $content)); |
| 305 |
$ret = $he->encode($compressionLevel); |
| 306 |
$he->sendAll(); |
| 307 |
|
| 308 |
return $ret; |
| 309 |
} |
| 310 |
|
| 311 |
/** |
| 312 |
* Is the browser an IE version earlier than 6 SP2? |
| 313 |
* |
| 314 |
* @return bool |
| 315 |
*/ |
| 316 |
public static function isBuggyIe() |
| 317 |
{ |
| 318 |
if (empty($_SERVER['HTTP_USER_AGENT'])) { |
| 319 |
return false; |
| 320 |
} |
| 321 |
$ua = $_SERVER['HTTP_USER_AGENT']; |
| 322 |
// quick escape for non-IEs |
| 323 |
if (0 !== strpos($ua, 'Mozilla/4.0 (compatible; MSIE ') |
| 324 |
|| false !== strpos($ua, 'Opera')) { |
| 325 |
return false; |
| 326 |
} |
| 327 |
// no regex = faaast |
| 328 |
$version = (float)substr($ua, 30); |
| 329 |
|
| 330 |
return self::$encodeToIe6 |
| 331 |
? ($version < 6 || ($version == 6 && false === strpos($ua, 'SV1'))) |
| 332 |
: ($version < 7); |
| 333 |
} |
| 334 |
|
| 335 |
protected $_content = ''; |
| 336 |
protected $_headers = array(); |
| 337 |
protected $_encodeMethod = array('', ''); |
| 338 |
protected $_useMbStrlen = false; |
| 339 |
} |
| 340 |
|
