theme/image.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * This file is responsible for serving the one theme and plugin images.
  19  *
  20  * @package   core
  21  * @copyright 2009 Petr Skoda (skodak)  {@link http://skodak.org}
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25
  26 // disable moodle specific debug messages and any errors in output,
  27 // comment out when debugging or better look into error log!
  28 define('NO_DEBUG_DISPLAY', true);
  29
  30 // we need just the values from config.php and minlib.php
  31 define('ABORT_AFTER_CONFIG', true);
  32 require('../config.php'); // this stops immediately at the beginning of lib/setup.php
  33
  34 if ($slashargument = min_get_slash_argument()) {
  35     $slashargument = ltrim($slashargument, '/');
  36     if (substr_count($slashargument, '/') < 3) {
  37         image_not_found();
  38     }
  39     if (strpos($slashargument, '_s/') === 0) {
  40         // Can't use SVG
  41         $slashargument = substr($slashargument, 3);
  42         $usesvg = false;
  43     } else {
  44         $usesvg = true;
  45     }
  46     // image must be last because it may contain "/"
  47     list($themename, $component, $rev, $image) = explode('/', $slashargument, 4);
  48     $themename = min_clean_param($themename, 'SAFEDIR');
  49     $component = min_clean_param($component, 'SAFEDIR');
  50     $rev       = min_clean_param($rev, 'INT');
  51     $image     = min_clean_param($image, 'SAFEPATH');
  52
  53 } else {
  54     $themename = min_optional_param('theme', 'standard', 'SAFEDIR');
  55     $component = min_optional_param('component', 'core', 'SAFEDIR');
  56     $rev       = min_optional_param('rev', -1, 'INT');
  57     $image     = min_optional_param('image', '', 'SAFEPATH');
  58     $usesvg    = (bool)min_optional_param('svg', '1', 'INT');
  59 }
  60
  61 if (empty($component) or $component === 'moodle' or $component === 'core') {
  62     $component = 'moodle';
  63 }
  64
  65 if (empty($image)) {
  66     image_not_found();
  67 }
  68
  69 if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
  70     // exists
  71 } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
  72     // exists
  73 } else {
  74     image_not_found();
  75 }
  76
  77 $candidatelocation = "$CFG->cachedir/theme/$themename/pix/$component";
  78 $etag = sha1("$themename/$component/$rev/$image");
  79
  80 if ($rev > -1) {
  81     if (file_exists("$candidatelocation/$image.error")) {
  82         // this is a major speedup if there are multiple missing images,
  83         // the only problem is that random requests may pollute our cache.
  84         image_not_found();
  85     }
  86     $cacheimage = false;
  87     if ($usesvg && file_exists("$candidatelocation/$image.svg")) {
  88         $cacheimage = "$candidatelocation/$image.svg";
  89         $ext = 'svg';
  90     } else if (file_exists("$candidatelocation/$image.png")) {
  91         $cacheimage = "$candidatelocation/$image.png";
  92         $ext = 'png';
  93     } else if (file_exists("$candidatelocation/$image.gif")) {
  94         $cacheimage = "$candidatelocation/$image.gif";
  95         $ext = 'gif';
  96     } else if (file_exists("$candidatelocation/$image.jpg")) {
  97         $cacheimage = "$candidatelocation/$image.jpg";
  98         $ext = 'jpg';
  99     } else if (file_exists("$candidatelocation/$image.jpeg")) {
 100         $cacheimage = "$candidatelocation/$image.jpeg";
 101         $ext = 'jpeg';
 102     } else if (file_exists("$candidatelocation/$image.ico")) {
 103         $cacheimage = "$candidatelocation/$image.ico";
 104         $ext = 'ico';
 105     }
 106     if ($cacheimage) {
 107         if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
 108             // we do not actually need to verify the etag value because our files
 109             // never change in cache because we increment the rev parameter
 110             $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 111             $mimetype = get_contenttype_from_ext($ext);
 112             header('HTTP/1.1 304 Not Modified');
 113             header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 114             header('Cache-Control: public, max-age='.$lifetime);
 115             header('Content-Type: '.$mimetype);
 116             header('Etag: '.$etag);
 117             die;
 118         }
 119         send_cached_image($cacheimage, $etag);
 120     }
 121 }
 122
 123 //=================================================================================
 124 // ok, now we need to start normal moodle script, we need to load all libs and $DB
 125 define('ABORT_AFTER_CONFIG_CANCEL', true);
 126
 127 define('NO_MOODLE_COOKIES', true); // Session not used here
 128 define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check
 129
 130 require("$CFG->dirroot/lib/setup.php");
 131
 132 $theme = theme_config::load($themename);
 133 $rev = theme_get_revision();
 134 $etag = sha1("$themename/$component/$rev/$image");
 135
 136 // We're not using SVG and there is no cached version of this file (in any format).
 137 // As we're going to be caching a format other than svg, and because svg use is conditional we need to ensure that at the same
 138 // time we cache a version of the SVG if it exists. If we don't do this other users who ask for SVG would not ever get it as
 139 // there is a cached image already of another format.
 140 // Remember this only gets run once before any candidate exists, and only if we want a cached revision.
 141 if (!$usesvg && $rev > -1) {
 142     $imagefile = $theme->resolve_image_location($image, $component, true);
 143     if (!empty($imagefile) && is_readable($imagefile)) {
 144         $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 145         $pathinfo = pathinfo($imagefile);
 146         // There is no SVG equivilant, we've just successfully cached an image of another format.
 147         if ($pathinfo['extension'] !== 'svg') {
 148             // Serve the file as we would in a normal request.
 149             if (connection_aborted()) {
 150                 die;
 151             }
 152             // make sure nothing failed
 153             clearstatcache();
 154             if (file_exists($cacheimage)) {
 155                 send_cached_image($cacheimage, $etag);
 156             }
 157             send_uncached_image($imagefile);
 158             exit;
 159         }
 160     }
 161 }
 162
 163 // Either SVG was requested or we've cached a SVG version and are ready to serve a regular format.
 164 $imagefile = $theme->resolve_image_location($image, $component, $usesvg);
 165 if (empty($imagefile) or !is_readable($imagefile)) {
 166     if ($rev > -1) {
 167         if (!file_exists($candidatelocation)) {
 168             @mkdir($candidatelocation, $CFG->directorypermissions, true);
 169         }
 170         // make note we can not find this file
 171         $cacheimage = "$candidatelocation/$image.error";
 172         $fp = fopen($cacheimage, 'w');
 173         fclose($fp);
 174     }
 175     image_not_found();
 176 }
 177
 178 if ($rev > -1) {
 179     $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 180     if (connection_aborted()) {
 181         die;
 182     }
 183     // make sure nothing failed
 184     clearstatcache();
 185     if (file_exists($cacheimage)) {
 186         send_cached_image($cacheimage, $etag);
 187     }
 188 }
 189
 190 send_uncached_image($imagefile);
 191
 192
 193 //=================================================================================
 194 //=== utility functions ==
 195 // we are not using filelib because we need to fine tune all header
 196 // parameters to get the best performance.
 197
 198 function send_cached_image($imagepath, $etag) {
 199     global $CFG;
 200     require("$CFG->dirroot/lib/xsendfilelib.php");
 201
 202     $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 203     $pathinfo = pathinfo($imagepath);
 204     $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 205
 206     $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 207
 208     header('Etag: '.$etag);
 209     header('Content-Disposition: inline; filename="'.$imagename.'"');
 210     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
 211     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 212     header('Pragma: ');
 213     header('Cache-Control: public, max-age='.$lifetime);
 214     header('Accept-Ranges: none');
 215     header('Content-Type: '.$mimetype);
 216     header('Content-Length: '.filesize($imagepath));
 217
 218     if (xsendfile($imagepath)) {
 219         die;
 220     }
 221
 222     // no need to gzip already compressed images ;-)
 223
 224     readfile($imagepath);
 225     die;
 226 }
 227
 228 function send_uncached_image($imagepath) {
 229     $pathinfo = pathinfo($imagepath);
 230     $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 231
 232     $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 233
 234     header('Content-Disposition: inline; filename="'.$imagename.'"');
 235     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 236     header('Expires: '. gmdate('D, d M Y H:i:s', time() + 15) .' GMT');
 237     header('Pragma: ');
 238     header('Accept-Ranges: none');
 239     header('Content-Type: '.$mimetype);
 240     header('Content-Length: '.filesize($imagepath));
 241
 242     readfile($imagepath);
 243     die;
 244 }
 245
 246 function image_not_found() {
 247     header('HTTP/1.0 404 not found');
 248     die('Image was not found, sorry.');
 249 }
 250
 251 function get_contenttype_from_ext($ext) {
 252     switch ($ext) {
 253         case 'svg':
 254             return 'image/svg+xml';
 255         case 'png':
 256             return 'image/png';
 257         case 'gif':
 258             return 'image/gif';
 259         case 'jpg':
 260         case 'jpeg':
 261             return 'image/jpeg';
 262         case 'ico':
 263             return 'image/vnd.microsoft.icon';
 264     }
 265     return 'document/unknown';
 266 }
 267
 268 /**
 269  * Caches a given image file.
 270  *
 271  * @param string $image The name of the image that was requested.
 272  * @param string $imagefile The location of the image file we want to cache.
 273  * @param string $candidatelocation The location to cache it in.
 274  * @return string The path to the cached image.
 275  */
 276 function cache_image($image, $imagefile, $candidatelocation) {
 277     global $CFG;
 278     $pathinfo = pathinfo($imagefile);
 279     $cacheimage = "$candidatelocation/$image.".$pathinfo['extension'];
 280
 281     clearstatcache();
 282     if (!file_exists(dirname($cacheimage))) {
 283         @mkdir(dirname($cacheimage), $CFG->directorypermissions, true);
 284     }
 285
 286     // Prevent serving of incomplete file from concurrent request,
 287     // the rename() should be more atomic than copy().
 288     ignore_user_abort(true);
 289     if (@copy($imagefile, $cacheimage.'.tmp')) {
 290         rename($cacheimage.'.tmp', $cacheimage);
 291         @chmod($cacheimage, $CFG->filepermissions);
 292         @unlink($cacheimage.'.tmp'); // just in case anything fails
 293     }
 294     return $cacheimage;
 295 }