Fixed bug #10266: No user authentication for >1 TYPO3 installation under one domain...
[Packages/TYPO3.CMS.git] / t3lib / class.gzip_encode.php
1 <?php
2 /**
3 * News: I had once said that when PHP 4.0.5 comes out I will reccomend the built in
4 * ob_gzhandler over my code unless you are generating flash or images on the fly.
5 *
6 * I was wrong. PHP 4.0.5 is out and ob_gzhandler doesn't work for me.
7 *
8 * Note: This is rather cool: http://leknor.com/code/gziped.php
9 * It will calculate the effects of this class on a page.
10 * compression level, cpu time, download time, etc
11 *
12 * Note: this may be better for some sites:
13 * http://www.remotecommunications.com/apache/mod_gzip/
14 * I've read that the above doesn't work with PHP output.
15 *
16 * Changes compared to the upstream version:
17 *
18 * 2007-03-27 Oliver Hader <oh@inpublica.de>
19 * - Fixed bug #4623: Content encoding with x-gzip not allowed
20 * - Fixed missing comments and line formats (cleaner)
21 * 2005-12-09 Peter Niederlag <peter@niederlag.de>
22 * - Fixed bug #1976: PHP5 type-conversion of string 'true' and boolean
23 *
24 * $Id$
25 *
26 * @author Sandy McArthur, Jr. <leknor@leknor.com>
27 */
28 /**
29 * [CLASS/FUNCTION INDEX of SCRIPT]
30 *
31 *
32 *
33 * 53: class gzip_encode
34 * 193: function gzip_encode($level = 3, $debug=false, $outputCompressedSizes=false)
35 * 268: function gzip_accepted()
36 * 317: function get_complevel()
37 * 342: function linux_loadavg()
38 * 363: function freebsd_loadavg()
39 *
40 * TOTAL FUNCTIONS: 5
41 * (This index is automatically created/updated by the extension "extdeveval")
42 *
43 */
44
45
46
47 /**
48 * gzip_encode - a class to gzip encode php output
49 *
50 * @author Sandy McArthur, Jr. <Leknor@Leknor.com>
51 * @package TYPO3
52 * @subpackage t3lib
53 */
54 class gzip_encode {
55 /**
56 * gzip_encode - a class to gzip encode php output
57 *
58 * By Sandy McArthur, Jr. <Leknor@Leknor.com>
59 *
60 * Copyright 2001 (c) All Rights Reserved, All Responsibility Yours.
61 * One very slight modification 2005 for PHP5 compatibility reasons for TYPO3 port by Peter Niederlag
62 *
63 * This code is released under the GNU LGPL Go read it over here:
64 * http://www.gnu.org/copyleft/lesser.html
65 *
66 * I do make one optional request, I would like an account on or a
67 * copy of where this code is used. If that is not possible then
68 * an email would be cool.
69 *
70 * How to use:
71 * 1. Output buffering has to be turned on. You can do this with ob_start()
72 * <http://php.net/manual/function.ob-start.php> or in the php config
73 * file. Nothing bad happens if output buffering isn't turned on, your
74 * page just won't get compressed.
75 * 2. Include the class file.
76 * 3. At the _very_ end of your script create an instance of the encode
77 * class.
78 *
79 * eg:
80 * ------------Start of file----------
81 * |<?php
82 * | ob_start();
83 * | include('class.gzip_encode.php');
84 * |?>
85 * |<HTML>
86 * |... the page ...
87 * |</HTML>
88 * |<?php
89 * | new gzip_encode();
90 * |?>
91 * -------------End of file-----------
92 *
93 * Things to note:
94 * 1. There is no space before the beginning of the file and the '<?php ' tag
95 * 2. The ob_start() line is optional if output buffering is turned on in
96 * the main config file.
97 * 3. Turning on and off output buffering just won't work.
98 * 4. There must be nothing after the last '?>' tag at the end of the file.
99 * Be careful of a space hiding there.
100 * 5. There are better ways to compress served content but I think this is
101 * the only way to compress php output.
102 * 6. Your auto_prepend_file is a good place for the ob_start() and
103 * your auto_append_file is a good place for new gzip_encode().
104 * 7. If you put new gzip_encode() in your auto.append file then you can
105 * call ob_end_flush() in your script to disable compression.
106 *
107 * This was written from scratch from info freely available on the web.
108 *
109 * These site(s) were useful to me:
110 * http://www.php.net/manual/
111 * http://www.ietf.org/rfc/rfc2616.txt (Sections: 3.5, 14.3, 14.11)
112 *
113 * Requirments:
114 * PHP 4.0.1+: I use the '===' operator, and output buffering, crc32();
115 * zlib: Needed for the gzip encoding. (Odds are you have it)
116 *
117 * Benchmarks:
118 * Take a look at http://Leknor.com/code/gziped.php and feed it a page to
119 * get an idea of how it will preform on your data or page.
120 *
121 * To Do:
122 * 1. I have reports of no content errors. I can't seem to duplicate this.
123 * Please visit my discussion boards if you think you may be able to help
124 * 2. The Accept-Encoding isn't handled to spec. Check out 14.3 in RFC 2616
125 * to see how it should be done.
126 *
127 * Change Log:
128 * 0.66: Big bug fix. It wouldn't compress when it should.
129 * 0.65: Fix for PHP-4.0.5 suddenly removing the connection_timeout() function.
130 * 0.62: Fixed a typo
131 * 0.61: Detect file types more like described in the magic number files, also
132 * added detection for gzip and pk zip files.
133 * 0.6: Detect common file types that shouldn't be compressed, mainly
134 * for images and swf (Shockwave Flash doesn't really accept gzip)
135 * 0.53: Made gzip_accepted() method so everyone can detect if a page
136 * will be gzip'ed with ease.
137 * 0.52: Detection and graceful handling of improper install/missing libs
138 * 0.51: Added FreeBSD load average detection.
139 * 0.5: Passing true as the first parameter will try to calculate the
140 * compression level from the server's load average. Passing true
141 * as the second parameter will turn on debugging.
142 * 0.4: No longer uses a temp file to compress the output. Should speed
143 * thing up a bit and reduce wear on your hard disk. Also test if
144 * the http headers have been sent.
145 * 0.31: Made a small change to the tempnam() line to hopefully be more
146 * portable.
147 * 0.3: Added code for the 'x-gzip'. This is untested, I don't know of
148 * any browser that uses it but the RFC said to look out for it.
149 * 0.2: Checks for 'gzip' in the Accept-Encoding header
150 * 0.1: First working version.
151 *
152 * Thanks To (Suggestions and stuff):
153 * ?@boas.anthro.mnsu.edu http://php.net/manual/function.gzcompress.php
154 * Kaoslord <kaoslord@chaos-productions.com>
155 * Michael R. Gile <gilem@wsg.net>
156 * Christian Hamm <chh@admaster.de>
157 *
158 * The most recent version is available at:
159 * http://Leknor.com/code/
160 *
161 */
162
163 var $_version = 0.66; // Version of the gzip_encode class
164
165 var $level; // Compression level
166 var $encoding; // Encoding type
167 var $crc; // crc of the output
168 var $size; // size of the uncompressed content
169 var $gzsize; // size of the compressed content
170
171 /**
172 * gzip_encode constructor - gzip encodes the current output buffer
173 * if the browser supports it.
174 *
175 * Note: all arguments are optionial.
176 *
177 * You can specify one of the following for the first argument:
178 * 0: No compression
179 * 1: Min compression
180 * ... Some compression (integer from 1 to 9)
181 * 9: Max compression
182 * true: Determin the compression level from the system load. The
183 * higher the load the less the compression.
184 *
185 * You can specify one of the following for the second argument:
186 * true: Don't actully output the compressed form but run as if it
187 * had. Used for debugging.
188 *
189 * @param integer $level: Define the level of compression between 0 (none) and 9 (best compression)
190 * @param boolean $debug: If true, no data will be outputted (default: false)
191 * @param boolean $outputCompressedSizes: If true, the original and compressed size appended as HTML (default: false)
192 * @return void
193 */
194 function gzip_encode($level=3, $debug=false, $outputCompressedSizes=false) {
195 if (!function_exists('gzcompress')) {
196 trigger_error('gzcompress not found, ' .
197 'zlib needs to be installed for gzip_encode',
198 E_USER_WARNING);
199 return;
200 }
201 if (!function_exists('crc32')) {
202 trigger_error('crc32() not found, ' .
203 'PHP >= 4.0.1 needed for gzip_encode', E_USER_WARNING);
204 return;
205 }
206 if (headers_sent()) return;
207 if (connection_status() !== 0) return;
208 $encoding = $this->gzip_accepted();
209 if (!$encoding) return;
210 $this->encoding = $encoding;
211
212 if (strtolower($level) == 'true' || $level === true) {
213 $level = $this->get_complevel();
214 }
215 $this->level = $level;
216
217 $contents = ob_get_contents();
218 if ($contents === false) return;
219
220 $gzdata = "\x1f\x8b\x08\x00\x00\x00\x00\x00"; // gzip header
221
222 // By Kasper Skaarhoj, start
223 if ($outputCompressedSizes) {
224 $contents.=chr(10)."<!-- Compressed, level ".$level.", original size was ".strlen($contents)." bytes. New size is ".strlen(gzcompress($contents, $level))." bytes -->";
225 $size = strlen($contents); // Must set again!
226 }
227 // By Kasper Skaarhoj, end
228
229 $size = strlen($contents);
230 $crc = crc32($contents);
231 $gzdata .= gzcompress($contents, $level);
232 $gzdata = substr($gzdata, 0, strlen($gzdata) - 4); // fix crc bug
233 $gzdata .= pack("V",$crc) . pack("V", $size);
234
235 $this->size = $size;
236 $this->crc = $crc;
237 $this->gzsize = strlen($gzdata);
238
239 if ($debug) {
240 return;
241 }
242
243 ob_end_clean();
244 Header('Content-Encoding: ' . $encoding);
245 Header('Content-Length: ' . strlen($gzdata));
246 Header('X-Content-Encoded-By: class.gzip_encode '.$this->_version);
247
248 echo $gzdata;
249 }
250
251
252 /**
253 * gzip_accepted() - Test headers for Accept-Encoding: gzip
254 * Returns: if proper headers aren't found: false
255 * if proper headers are found: 'gzip' or 'x-gzip'
256 *
257 * Tip: using this function you can test if the class will gzip the output
258 * without actually compressing it yet, eg:
259 * if (gzip_encode::gzip_accepted()) {
260 * echo "Page will be gziped";
261 * }
262 * note the double colon syntax, I don't know where it is documented but
263 * somehow it got in my brain.
264 *
265 * @return mixed Returns 'gzip' if the client browser accepts gzip encoding, otherwise false
266 */
267 function gzip_accepted() {
268 // Checks, if the accepted encoding supports gzip or x-gzip.
269 // Furthermore a qvalue check is done. "gzip;q=0" means no gzip accepted at all.
270 $acceptEncoding = t3lib_div::getIndpEnv('HTTP_ACCEPT_ENCODING');
271 if (preg_match('/(^|,\s*)(x-)?gzip(;q=(\d(\.\d+)?))?(,|$)/i', $acceptEncoding, $match) && ($match[4] === '' || $match[4] > 0)) {
272 $encoding = 'gzip';
273 } else {
274 return false;
275 }
276
277 // Test file type. I wish I could get HTTP response headers.
278 $magic = substr(ob_get_contents(),0,4);
279 if (substr($magic,0,2) === '^_') {
280 // gzip data
281 $encoding = false;
282 } else if (substr($magic,0,3) === 'GIF') {
283 // gif images
284 $encoding = false;
285 } else if (substr($magic,0,2) === "\xFF\xD8") {
286 // jpeg images
287 $encoding = false;
288 } else if (substr($magic,0,4) === "\x89PNG") {
289 // png images
290 $encoding = false;
291 } else if (substr($magic,0,3) === 'FWS') {
292 // Don't gzip Shockwave Flash files. Flash on windows incorrectly
293 // claims it accepts gzip'd content.
294 $encoding = false;
295 } else if (substr($magic,0,2) === 'PK') {
296 // pk zip file
297 $encoding = false;
298 }
299
300 return $encoding;
301 }
302
303 /**
304 * get_complevel() - The level of compression we should use.
305 *
306 * Returns an int between 0 and 9 inclusive.
307 *
308 * Tip: $gzleve = gzip_encode::get_complevel(); to get the compression level
309 * that will be used with out actually compressing the output.
310 *
311 * Help: if you use an OS other then linux please send me code to make
312 * this work with your OS - Thanks
313 *
314 * @return integer Suggests a level of compression (0..9) for the current situation
315 */
316 function get_complevel() {
317 $uname = posix_uname();
318 switch ($uname['sysname']) {
319 case 'Linux':
320 $cl = (1 - $this->linux_loadavg()) * 10;
321 $level = (int)max(min(9, $cl), 0);
322 break;
323 case 'FreeBSD':
324 $cl = (1 - $this->freebsd_loadavg()) * 10;
325 $level = (int)max(min(9, $cl), 0);
326 break;
327 default:
328 $level = 3;
329 break;
330 }
331 return $level;
332 }
333
334 /**
335 * linux_loadavg() - Gets the max() system load average from /proc/loadavg
336 *
337 * The max() Load Average will be returned
338 *
339 * @return float Returns the current load average
340 */
341 function linux_loadavg() {
342 $buffer = '0 0 0';
343 $f = @fopen('/proc/loadavg', 'rb');
344 if ($f) {
345 if (!feof($f)) {
346 $buffer = fgets($f, 1024);
347 }
348 fclose($f);
349 }
350 $load = explode(' ', $buffer);
351 return max((float)$load[0], (float)$load[1], (float)$load[2]);
352 }
353
354 /**
355 * freebsd_loadavg() - Gets the max() system load average from uname(1)
356 *
357 * The max() Load Average will be returned
358 *
359 * I've been told the code below will work on solaris too, anyone wanna
360 * test it?
361 *
362 * @return float Returns the current load average
363 */
364 function freebsd_loadavg() {
365 $buffer= `uptime`;
366 $load = array();
367 ereg("averag(es|e): ([0-9][.][0-9][0-9]), ([0-9][.][0-9][0-9]), ([0-9][.][0-9][0-9]*)", $buffer, $load);
368
369 return max((float)$load[2], (float)$load[3], (float)$load[4]);
370 }
371 }
372
373 ?>