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Differences Between: [Versions 310 and 311] [Versions 310 and 400] [Versions 310 and 401] [Versions 310 and 402] [Versions 310 and 403] [Versions 39 and 310]

   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      $component = 'core';
  63  }
  64  
  65  if (empty($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->localcachedir/theme/$rev/$themename/pix/$component";
  78  $etag = sha1("$rev/$themename/$component/$image");
  79  
  80  if ($rev > 0) {
  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              // 90 days only - based on Moodle point release cadence being every 3 months.
 111              $lifetime = 60 * 60 * 24 * 90;
 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.', no-transform');
 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  $themerev = theme_get_revision();
 135  
 136  if ($themerev <= 0 or $rev != $themerev) {
 137      // Do not send caching headers if they do not request current revision,
 138      // we do not want to pollute browser caches with outdated images.
 139      $imagefile = $theme->resolve_image_location($image, $component, $usesvg);
 140      if (empty($imagefile) or !is_readable($imagefile)) {
 141          image_not_found();
 142      }
 143      send_uncached_image($imagefile);
 144  }
 145  
 146  make_localcache_directory('theme', false);
 147  
 148  // At this stage caching is enabled, and either:
 149  // * we have no cached copy of the image in any format (either SVG, or non-SVG); or
 150  // * we have a cached copy of the SVG, but the non-SVG was requested by the browser.
 151  //
 152  // Because of the way in which the cache return code works above:
 153  // * if we are allowed to return SVG, we do not need to cache the non-SVG version; however
 154  // * if the browser has requested the non-SVG version, we *must* cache _both_ the SVG, and the non-SVG versions.
 155  
 156  // First get all copies - including, potentially, the SVG version.
 157  $imagefile = $theme->resolve_image_location($image, $component, true);
 158  
 159  if (empty($imagefile) || !is_readable($imagefile)) {
 160      // Unable to find a copy of the image file in any format.
 161      // We write a .error file for the image now - this will be used above when searching for cached copies to prevent
 162      // trying to find the image in the future.
 163      if (!file_exists($candidatelocation)) {
 164          @mkdir($candidatelocation, $CFG->directorypermissions, true);
 165      }
 166      // Make note we can not find this file.
 167      $cacheimage = "$candidatelocation/$image.error";
 168      $fp = fopen($cacheimage, 'w');
 169      fclose($fp);
 170      image_not_found();
 171  }
 172  
 173  // The image was found, and it is readable.
 174  $pathinfo = pathinfo($imagefile);
 175  
 176  // Attempt to cache it if necessary.
 177  // We don't really want to overwrite any existing cache items just for the sake of it.
 178  $cacheimage = "$candidatelocation/$image.{$pathinfo['extension']}";
 179  if (!file_exists($cacheimage)) {
 180      // We don't already hold a cached copy of this image. Cache it now.
 181      $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 182  }
 183  
 184  if (!$usesvg && $pathinfo['extension'] === 'svg') {
 185      // The browser has requested that a non-SVG version be returned.
 186      // The version found so far is the SVG version - try and find the non-SVG version.
 187      $imagefile = $theme->resolve_image_location($image, $component, false);
 188      if (empty($imagefile) || !is_readable($imagefile)) {
 189          // A non-SVG file could not be found at all.
 190          // The browser has requested a non-SVG version, so we must return image_not_found().
 191          // We must *not* write an .error file because the SVG is available.
 192          image_not_found();
 193      }
 194  
 195      // An non-SVG version of image was found - cache it.
 196      // This will be used below in the image serving code.
 197      $cacheimage = cache_image($image, $imagefile, $candidatelocation);
 198  }
 199  
 200  if (connection_aborted()) {
 201      // Request was cancelled - do not send anything.
 202      die;
 203  }
 204  
 205  // Make sure nothing failed.
 206  clearstatcache();
 207  if (file_exists($cacheimage)) {
 208      // The cached copy was found, and is accessible. Serve it.
 209      send_cached_image($cacheimage, $etag);
 210  }
 211  
 212  send_uncached_image($imagefile);
 213  
 214  //=================================================================================
 215  //=== utility functions ==
 216  // we are not using filelib because we need to fine tune all header
 217  // parameters to get the best performance.
 218  
 219  function send_cached_image($imagepath, $etag) {
 220      global $CFG;
 221      require("$CFG->dirroot/lib/xsendfilelib.php");
 222  
 223      // 90 days only - based on Moodle point release cadence being every 3 months.
 224      $lifetime = 60 * 60 * 24 * 90;
 225      $pathinfo = pathinfo($imagepath);
 226      $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 227  
 228      $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 229  
 230      header('Etag: "'.$etag.'"');
 231      header('Content-Disposition: inline; filename="'.$imagename.'"');
 232      header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
 233      header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 234      header('Pragma: ');
 235      header('Cache-Control: public, max-age='.$lifetime.', no-transform, immutable');
 236      header('Accept-Ranges: none');
 237      header('Content-Type: '.$mimetype);
 238  
 239      if (xsendfile($imagepath)) {
 240          die;
 241      }
 242  
 243      if ($mimetype === 'image/svg+xml') {
 244          // SVG format is a text file. So we can compress SVG files.
 245          if (!min_enable_zlib_compression()) {
 246              header('Content-Length: '.filesize($imagepath));
 247          }
 248      } else {
 249          // No need to compress other image formats.
 250          header('Content-Length: '.filesize($imagepath));
 251      }
 252  
 253      readfile($imagepath);
 254      die;
 255  }
 256  
 257  function send_uncached_image($imagepath) {
 258      $pathinfo = pathinfo($imagepath);
 259      $imagename = $pathinfo['filename'].'.'.$pathinfo['extension'];
 260  
 261      $mimetype = get_contenttype_from_ext($pathinfo['extension']);
 262  
 263      header('Content-Disposition: inline; filename="'.$imagename.'"');
 264      header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
 265      header('Expires: '. gmdate('D, d M Y H:i:s', time() + 15) .' GMT');
 266      header('Pragma: ');
 267      header('Accept-Ranges: none');
 268      header('Content-Type: '.$mimetype);
 269      header('Content-Length: '.filesize($imagepath));
 270  
 271      readfile($imagepath);
 272      die;
 273  }
 274  
 275  function image_not_found() {
 276      header('HTTP/1.0 404 not found');
 277      die('Image was not found, sorry.');
 278  }
 279  
 280  function get_contenttype_from_ext($ext) {
 281      switch ($ext) {
 282          case 'svg':
 283              return 'image/svg+xml';
 284          case 'png':
 285              return 'image/png';
 286          case 'gif':
 287              return 'image/gif';
 288          case 'jpg':
 289          case 'jpeg':
 290              return 'image/jpeg';
 291          case 'ico':
 292              return 'image/vnd.microsoft.icon';
 293      }
 294      return 'document/unknown';
 295  }
 296  
 297  /**
 298   * Caches a given image file.
 299   *
 300   * @param string $image The name of the image that was requested.
 301   * @param string $imagefile The location of the image file we want to cache.
 302   * @param string $candidatelocation The location to cache it in.
 303   * @return string The path to the cached image.
 304   */
 305  function cache_image($image, $imagefile, $candidatelocation) {
 306      global $CFG;
 307      $pathinfo = pathinfo($imagefile);
 308      $cacheimage = "$candidatelocation/$image.".$pathinfo['extension'];
 309  
 310      clearstatcache();
 311      if (!file_exists(dirname($cacheimage))) {
 312          @mkdir(dirname($cacheimage), $CFG->directorypermissions, true);
 313      }
 314  
 315      // Prevent serving of incomplete file from concurrent request,
 316      // the rename() should be more atomic than copy().
 317      ignore_user_abort(true);
 318      if (@copy($imagefile, $cacheimage.'.tmp')) {
 319          rename($cacheimage.'.tmp', $cacheimage);
 320          @chmod($cacheimage, $CFG->filepermissions);
 321          @unlink($cacheimage.'.tmp'); // just in case anything fails
 322      }
 323      return $cacheimage;
 324  }