theme/image.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * This file is responsible for serving the one theme and plugin images.
  20  *
  21  * @package   moodlecore
  22  * @copyright 2009 Petr Skoda (skodak)  {@link http://skodak.org}
  23  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26
  27 // disable moodle specific debug messages and any errors in output,
  28 // comment out when debugging or better look into error log!
  29 define('NO_DEBUG_DISPLAY', true);
  30
  31 // we need just the values from config.php and minlib.php
  32 define('ABORT_AFTER_CONFIG', true);
  33 require('../config.php'); // this stops immediately at the beginning of lib/setup.php
  34
  35 if ($slashargument = min_get_slash_argument()) {
  36     $slashargument = ltrim($slashargument, '/');
  37     if (substr_count($slashargument, '/') < 3) {
  38         image_not_found();
  39     }
  40     if (strpos($slashargument, '_s/') === 0) {
  41         // Can't use SVG
  42         $slashargument = substr($slashargument, 3);
  43         $usesvg = false;
  44     } else {
  45         $usesvg = true;
  46     }
  47     // image must be last because it may contain "/"
  48     list($themename, $component, $rev, $image) = explode('/', $slashargument, 4);
  49     $themename = min_clean_param($themename, 'SAFEDIR');
  50     $component = min_clean_param($component, 'SAFEDIR');
  51     $rev       = min_clean_param($rev, 'INT');
  52     $image     = min_clean_param($image, 'SAFEPATH');
  53
  54 } else {
  55     $themename = min_optional_param('theme', 'standard', 'SAFEDIR');
  56     $component = min_optional_param('component', 'core', 'SAFEDIR');
  57     $rev       = min_optional_param('rev', -1, 'INT');
  58     $image     = min_optional_param('image', '', 'SAFEPATH');
  59     $usesvg    = (bool)min_optional_param('svg', '1', 'INT');
  60 }
  61
  62 if (empty($component) or $component === 'moodle' or $component === 'core') {
  63     $component = 'moodle';
  64 }
  65
  66 if (empty($image)) {
  67     image_not_found();
  68 }
  69
  70 if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
  71     // exists
  72 } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
  73     // exists
  74 } else {
  75     image_not_found();
  76 }
  77
  78 $candidatelocation = "$CFG->cachedir/theme/$themename/pix/$component";
  79 $etag = sha1("$themename/$component/$rev/$image");
  80
  81 if ($rev > -1) {
  82     if (file_exists("$candidatelocation/$image.error")) {
  83         // this is a major speedup if there are multiple missing images,
  84         // the only problem is that random requests may pollute our cache.
  85         image_not_found();
  86     }
  87     $cacheimage = false;
  88     if ($usesvg && file_exists("$candidatelocation/$image.svg")) {
  89         $cacheimage = "$candidatelocation/$image.svg";
  90         $ext = 'svg';
  91     } else if (file_exists("$candidatelocation/$image.png")) {
  92         $cacheimage = "$candidatelocation/$image.png";
  93         $ext = 'png';
  94     } else if (file_exists("$candidatelocation/$image.gif")) {
  95         $cacheimage = "$candidatelocation/$image.gif";
  96         $ext = 'gif';
  97     } else if (file_exists("$candidatelocation/$image.jpg")) {
  98         $cacheimage = "$candidatelocation/$image.jpg";
  99         $ext = 'jpg';
 100     } else if (file_exists("$candidatelocation/$image.jpeg")) {
 101         $cacheimage = "$candidatelocation/$image.jpeg";
 102         $ext = 'jpeg';
 103     } else if (file_exists("$candidatelocation/$image.ico")) {
 104         $cacheimage = "$candidatelocation/$image.ico";
 105         $ext = 'ico';
 106     }
 107     if ($cacheimage) {
 108         if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
 109             // we do not actually need to verify the etag value because our files
 110             // never change in cache because we increment the rev parameter
 111             $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 112             $mimetype = get_contenttype_from_ext($ext);
 113             header('HTTP/1.1 304 Not Modified');
 114             header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 115             header('Cache-Control: public, max-age='.$lifetime);
 116             header('Content-Type: '.$mimetype);
 117             header('Etag: '.$etag);
 118             die;
 119         }
 120         send_cached_image($cacheimage, $etag);
 121     }
 122 }
 123
 124 //=================================================================================
 125 // ok, now we need to start normal moodle script, we need to load all libs and $DB
 126 define('ABORT_AFTER_CONFIG_CANCEL', true);
 127
 128 define('NO_MOODLE_COOKIES', true); // Session not used here
 129 define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check
 130
 131 require("$CFG->dirroot/lib/setup.php");
 132
 133 $theme = theme_config::load($themename);
 134 $rev = theme_get_revision();
 135 $etag = sha1("$themename/$component/$rev/$image");
 136
 137 // We're not using SVG and there is no cached version of this file (in any format).
 138 // As we're going to be caching a format other than svg, and because svg use is conditional we need to ensure that at the same
 139 // time we cache a version of the SVG if it exists. If we don't do this other users who ask for SVG would not ever get it as
 140 // there is a cached image already of another format.
 141 // Remember this only gets run once before any candidate exists, and only if we want a cached revision.
 142 if (!$usesvg && $rev > -1) {
 143     $imagefile = $theme->resolve_image_location($image, $component, true);
 144     if (!empty($imagefile) && is_readable($imagefile)) {
 145         $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 146         $pathinfo = pathinfo($imagefile);
 147         // There is no SVG equivilant, we've just successfully cached an image of another format.
 148         if ($pathinfo['extension'] !== 'svg') {
 149             // Serve the file as we would in a normal request.
 150             if (connection_aborted()) {
 151                 die;
 152             }
 153             // make sure nothing failed
 154             clearstatcache();
 155             if (file_exists($cacheimage)) {
 156                 send_cached_image($cacheimage, $etag);
 157             }
 158             send_uncached_image($imagefile);
 159             exit;
 160         }
 161     }
 162 }
 163
 164 // Either SVG was requested or we've cached a SVG version and are ready to serve a regular format.
 165 $imagefile = $theme->resolve_image_location($image, $component, $usesvg);
 166 if (empty($imagefile) or !is_readable($imagefile)) {
 167     if ($rev > -1) {
 168         if (!file_exists($candidatelocation)) {
 169             @mkdir($candidatelocation, $CFG->directorypermissions, true);
 170         }
 171         // make note we can not find this file
 172         $cacheimage = "$candidatelocation/$image.error";
 173         $fp = fopen($cacheimage, 'w');
 174         fclose($fp);
 175     }
 176     image_not_found();
 177 }
 178
 179 if ($rev > -1) {
 180     $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 181     if (connection_aborted()) {
 182         die;
 183     }
 184     // make sure nothing failed
 185     clearstatcache();
 186     if (file_exists($cacheimage)) {
 187         send_cached_image($cacheimage, $etag);
 188     }
 189 }
 190
 191 send_uncached_image($imagefile);
 192
 193
 194 //=================================================================================
 195 //=== utility functions ==
 196 // we are not using filelib because we need to fine tune all header
 197 // parameters to get the best performance.
 198
 199 function send_cached_image($imagepath, $etag) {
 200     global $CFG;
 201     require("$CFG->dirroot/lib/xsendfilelib.php");
 202
 203     $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 204     $pathinfo = pathinfo($imagepath);
 205     $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 206
 207     $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 208
 209     header('Etag: '.$etag);
 210     header('Content-Disposition: inline; filename="'.$imagename.'"');
 211     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
 212     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 213     header('Pragma: ');
 214     header('Cache-Control: public, max-age='.$lifetime);
 215     header('Accept-Ranges: none');
 216     header('Content-Type: '.$mimetype);
 217     header('Content-Length: '.filesize($imagepath));
 218
 219     if (xsendfile($imagepath)) {
 220         die;
 221     }
 222
 223     // no need to gzip already compressed images ;-)
 224
 225     readfile($imagepath);
 226     die;
 227 }
 228
 229 function send_uncached_image($imagepath) {
 230     $pathinfo = pathinfo($imagepath);
 231     $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 232
 233     $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 234
 235     header('Content-Disposition: inline; filename="'.$imagename.'"');
 236     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 237     header('Expires: '. gmdate('D, d M Y H:i:s', time() + 15) .' GMT');
 238     header('Pragma: ');
 239     header('Accept-Ranges: none');
 240     header('Content-Type: '.$mimetype);
 241     header('Content-Length: '.filesize($imagepath));
 242
 243     readfile($imagepath);
 244     die;
 245 }
 246
 247 function image_not_found() {
 248     header('HTTP/1.0 404 not found');
 249     die('Image was not found, sorry.');
 250 }
 251
 252 function get_contenttype_from_ext($ext) {
 253     switch ($ext) {
 254         case 'svg':
 255             return 'image/svg+xml';
 256         case 'png':
 257             return 'image/png';
 258         case 'gif':
 259             return 'image/gif';
 260         case 'jpg':
 261         case 'jpeg':
 262             return 'image/jpeg';
 263         case 'ico':
 264             return 'image/vnd.microsoft.icon';
 265     }
 266     return 'document/unknown';
 267 }
 268
 269 /**
 270  * Caches a given image file.
 271  *
 272  * @param string $image The name of the image that was requested.
 273  * @param string $imagefile The location of the image file we want to cache.
 274  * @param string $candidatelocation The location to cache it in.
 275  * @return string The path to the cached image.
 276  */
 277 function cache_image($image, $imagefile, $candidatelocation) {
 278     global $CFG;
 279     $pathinfo = pathinfo($imagefile);
 280     $cacheimage = "$candidatelocation/$image.".$pathinfo['extension'];
 281
 282     clearstatcache();
 283     if (!file_exists(dirname($cacheimage))) {
 284         @mkdir(dirname($cacheimage), $CFG->directorypermissions, true);
 285     }
 286
 287     // Prevent serving of incomplete file from concurrent request,
 288     // the rename() should be more atomic than copy().
 289     ignore_user_abort(true);
 290     if (@copy($imagefile, $cacheimage.'.tmp')) {
 291         rename($cacheimage.'.tmp', $cacheimage);
 292         @chmod($cacheimage, $CFG->filepermissions);
 293         @unlink($cacheimage.'.tmp'); // just in case anything fails
 294     }
 295     return $cacheimage;
 296 }