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($slashargument, '/') < 3) {
  38         image_not_found();
  39     }
  40     // image must be last because it may contain "/"
  41     list($themename, $component, $rev, $image) = explode('/', $slashargument, 4);
  42     $themename = min_clean_param($themename, 'SAFEDIR');
  43     $component = min_clean_param($component, 'SAFEDIR');
  44     $rev       = min_clean_param($rev, 'INT');
  45     $image     = min_clean_param($image, 'SAFEPATH');
  46
  47 } else {
  48     $themename = min_optional_param('theme', 'standard', 'SAFEDIR');
  49     $component = min_optional_param('component', 'core', 'SAFEDIR');
  50     $rev       = min_optional_param('rev', -1, 'INT');
  51     $image     = min_optional_param('image', '', 'SAFEPATH');
  52 }
  53
  54 if (empty($component) or $component === 'moodle' or $component === 'core') {
  55     $component = 'moodle';
  56 }
  57
  58 if (empty($image)) {
  59     image_not_found();
  60 }
  61
  62 if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
  63     // exists
  64 } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
  65     // exists
  66 } else {
  67     image_not_found();
  68 }
  69
  70 $candidatelocation = "$CFG->cachedir/theme/$themename/pix/$component";
  71 $etag = sha1("$themename/$component/$rev/$image");
  72
  73 if ($rev > -1) {
  74     if (file_exists("$candidatelocation/$image.error")) {
  75         // this is a major speedup if there are multiple missing images,
  76         // the only problem is that random requests may pollute our cache.
  77         image_not_found();
  78     }
  79     $cacheimage = false;
  80     if (file_exists("$candidatelocation/$image.gif")) {
  81         $cacheimage = "$candidatelocation/$image.gif";
  82         $ext = 'gif';
  83     } else if (file_exists("$candidatelocation/$image.png")) {
  84         $cacheimage = "$candidatelocation/$image.png";
  85         $ext = 'png';
  86     } else if (file_exists("$candidatelocation/$image.jpg")) {
  87         $cacheimage = "$candidatelocation/$image.jpg";
  88         $ext = 'jpg';
  89     } else if (file_exists("$candidatelocation/$image.jpeg")) {
  90         $cacheimage = "$candidatelocation/$image.jpeg";
  91         $ext = 'jpeg';
  92     } else if (file_exists("$candidatelocation/$image.ico")) {
  93         $cacheimage = "$candidatelocation/$image.ico";
  94         $ext = 'ico';
  95     }
  96     if ($cacheimage) {
  97         if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
  98             // we do not actually need to verify the etag value because our files
  99             // never change in cache because we increment the rev parameter
 100             $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 101             $mimetype = get_contenttype_from_ext($ext);
 102             header('HTTP/1.1 304 Not Modified');
 103             header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 104             header('Cache-Control: public, max-age='.$lifetime);
 105             header('Content-Type: '.$mimetype);
 106             header('Etag: '.$etag);
 107             die;
 108         }
 109         send_cached_image($cacheimage, $etag);
 110     }
 111 }
 112
 113 //=================================================================================
 114 // ok, now we need to start normal moodle script, we need to load all libs and $DB
 115 define('ABORT_AFTER_CONFIG_CANCEL', true);
 116
 117 define('NO_MOODLE_COOKIES', true); // Session not used here
 118 define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check
 119
 120 require("$CFG->dirroot/lib/setup.php");
 121
 122 $theme = theme_config::load($themename);
 123 $imagefile = $theme->resolve_image_location($image, $component);
 124
 125 $rev = theme_get_revision();
 126 $etag = sha1("$themename/$component/$rev/$image");
 127
 128 if (empty($imagefile) or !is_readable($imagefile)) {
 129     if ($rev > -1) {
 130         if (!file_exists($candidatelocation)) {
 131             @mkdir($candidatelocation, $CFG->directorypermissions, true);
 132         }
 133         // make note we can not find this file
 134         $cacheimage = "$candidatelocation/$image.error";
 135         $fp = fopen($cacheimage, 'w');
 136         fclose($fp);
 137     }
 138     image_not_found();
 139 }
 140
 141 if ($rev > -1) {
 142     $pathinfo = pathinfo($imagefile);
 143     $cacheimage = "$candidatelocation/$image.".$pathinfo['extension'];
 144
 145     clearstatcache();
 146     if (!file_exists(dirname($cacheimage))) {
 147         @mkdir(dirname($cacheimage), $CFG->directorypermissions, true);
 148     }
 149
 150     // Prevent serving of incomplete file from concurrent request,
 151     // the rename() should be more atomic than copy().
 152     ignore_user_abort(true);
 153     if (@copy($imagefile, $cacheimage.'.tmp')) {
 154         rename($cacheimage.'.tmp', $cacheimage);
 155         @chmod($cacheimage, $CFG->filepermissions);
 156         @unlink($cacheimage.'.tmp'); // just in case anything fails
 157     }
 158     ignore_user_abort(false);
 159     if (connection_aborted()) {
 160         die;
 161     }
 162     // make sure nothing failed
 163     clearstatcache();
 164     if (file_exists($cacheimage)) {
 165         send_cached_image($cacheimage, $etag);
 166     }
 167 }
 168
 169 send_uncached_image($imagefile);
 170
 171
 172 //=================================================================================
 173 //=== utility functions ==
 174 // we are not using filelib because we need to fine tune all header
 175 // parameters to get the best performance.
 176
 177 function send_cached_image($imagepath, $etag) {
 178     global $CFG;
 179     require("$CFG->dirroot/lib/xsendfilelib.php");
 180
 181     $lifetime = 60*60*24*60; // 60 days only - the revision may get incremented quite often
 182     $pathinfo = pathinfo($imagepath);
 183     $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 184
 185     $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 186
 187     header('Etag: '.$etag);
 188     header('Content-Disposition: inline; filename="'.$imagename.'"');
 189     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
 190     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 191     header('Pragma: ');
 192     header('Cache-Control: public, max-age='.$lifetime);
 193     header('Accept-Ranges: none');
 194     header('Content-Type: '.$mimetype);
 195     header('Content-Length: '.filesize($imagepath));
 196
 197     if (xsendfile($imagepath)) {
 198         die;
 199     }
 200
 201     // no need to gzip already compressed images ;-)
 202
 203     readfile($imagepath);
 204     die;
 205 }
 206
 207 function send_uncached_image($imagepath) {
 208     $pathinfo = pathinfo($imagepath);
 209     $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 210
 211     $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 212
 213     header('Content-Disposition: inline; filename="'.$imagename.'"');
 214     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 215     header('Expires: '. gmdate('D, d M Y H:i:s', time() + 15) .' GMT');
 216     header('Pragma: ');
 217     header('Accept-Ranges: none');
 218     header('Content-Type: '.$mimetype);
 219     header('Content-Length: '.filesize($imagepath));
 220
 221     readfile($imagepath);
 222     die;
 223 }
 224
 225 function image_not_found() {
 226     header('HTTP/1.0 404 not found');
 227     die('Image was not found, sorry.');
 228 }
 229
 230 function get_contenttype_from_ext($ext) {
 231     switch ($ext) {
 232         case 'gif':
 233             return 'image/gif';
 234         case 'png':
 235             return 'image/png';
 236         case 'jpg':
 237         case 'jpeg':
 238             return 'image/jpeg';
 239         case 'ico':
 240             return 'image/vnd.microsoft.icon';
 241     }
 242     return 'document/unknown';
 243 }