[Summary view]

Differences Between: [Versions 310 and 401] [Versions 311 and 401] [Versions 39 and 401]

   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 huge CSS of each theme.
  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  // Disable moodle specific debug messages and any errors in output,
  26  // comment out when debugging or better look into error log!
  27  define('NO_DEBUG_DISPLAY', true);
  28  
  29  define('ABORT_AFTER_CONFIG', true);
  30  require('../config.php');
  31  require_once($CFG->dirroot.'/lib/csslib.php');
  32  
  33  if ($slashargument = min_get_slash_argument()) {
  34      $slashargument = ltrim($slashargument, '/');
  35      if (substr_count($slashargument, '/') < 2) {
  36          css_send_css_not_found();
  37      }
  38  
  39      if (strpos($slashargument, '_s/') === 0) {
  40          // Can't use SVG.
  41          $slashargument = substr($slashargument, 3);
  42          $usesvg = false;
  43      } else {
  44          $usesvg = true;
  45      }
  46  
  47      list($themename, $rev, $type) = explode('/', $slashargument, 3);
  48      $themename = min_clean_param($themename, 'SAFEDIR');
  49      $rev       = min_clean_param($rev, 'RAW');
  50      $type      = min_clean_param($type, 'SAFEDIR');
  51  
  52  } else {
  53      $themename = min_optional_param('theme', 'standard', 'SAFEDIR');
  54      $rev       = min_optional_param('rev', 0, 'RAW');
  55      $type      = min_optional_param('type', 'all', 'SAFEDIR');
  56      $usesvg    = (bool)min_optional_param('svg', '1', 'INT');
  57  }
  58  
  59  // Check if we received a theme sub revision which allows us
  60  // to handle local caching on a per theme basis.
  61  $values = explode('_', $rev);
  62  $rev = min_clean_param(array_shift($values), 'INT');
  63  $themesubrev = array_shift($values);
  64  
  65  if (!is_null($themesubrev)) {
  66      $themesubrev = min_clean_param($themesubrev, 'INT');
  67  }
  68  
  69  // Note: We only check validity of the revision number here, we do not check the theme sub-revision because this is
  70  // not solely based on time.
  71  if (!min_is_revision_valid_and_current($rev)) {
  72      // If the rev is invalid, normalise it to -1 to disable all caching.
  73      $rev = -1;
  74  }
  75  
  76  // Check that type fits into the expected values.
  77  if (!in_array($type, ['all', 'all-rtl', 'editor', 'editor-rtl'])) {
  78      css_send_css_not_found();
  79  }
  80  
  81  if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
  82      // The theme exists in standard location - ok.
  83  } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
  84      // Alternative theme location contains this theme - ok.
  85  } else {
  86      header('HTTP/1.0 404 not found');
  87      die('Theme was not found, sorry.');
  88  }
  89  
  90  $candidatedir = "$CFG->localcachedir/theme/$rev/$themename/css";
  91  $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg);
  92  $etag = theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg);
  93  
  94  if (file_exists($candidatesheet)) {
  95      if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
  96          // We do not actually need to verify the etag value because our files
  97          // never change in cache because we increment the rev counter.
  98          css_send_unmodified(filemtime($candidatesheet), $etag);
  99      }
 100      css_send_cached_css($candidatesheet, $etag);
 101  }
 102  
 103  // Ok, now we need to start normal moodle script, we need to load all libs and $DB.
 104  define('ABORT_AFTER_CONFIG_CANCEL', true);
 105  
 106  define('NO_MOODLE_COOKIES', true); // Session not used here.
 107  define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check.
 108  
 109  require("$CFG->dirroot/lib/setup.php");
 110  
 111  $theme = theme_config::load($themename);
 112  $theme->force_svg_use($usesvg);
 113  $theme->set_rtl_mode(substr($type, -4) === '-rtl');
 114  
 115  $themerev = theme_get_revision();
 116  $currentthemesubrev = theme_get_sub_revision_for_theme($themename);
 117  
 118  $cache = true;
 119  // If the client is requesting a revision that doesn't match both
 120  // the global theme revision and the theme specific revision then
 121  // tell the browser not to cache this style sheet because it's
 122  // likely being regenerated.
 123  if ($themerev <= 0 or $themerev != $rev or $themesubrev != $currentthemesubrev) {
 124      $rev = $themerev;
 125      $themesubrev = $currentthemesubrev;
 126      $cache = false;
 127  
 128      $candidatedir = "$CFG->localcachedir/theme/$rev/$themename/css";
 129      $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg);
 130      $etag = theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg);
 131  }
 132  
 133  make_localcache_directory('theme', false);
 134  
 135  if ($type === 'editor' || $type === 'editor-rtl') {
 136      $csscontent = $theme->get_css_content_editor();
 137  
 138      if ($cache) {
 139          css_store_css($theme, $candidatesheet, $csscontent);
 140          css_send_cached_css($candidatesheet, $etag);
 141      } else {
 142          css_send_uncached_css($csscontent);
 143      }
 144  
 145  }
 146  
 147  if (($fallbacksheet = theme_styles_fallback_content($theme)) && !$theme->has_css_cached_content()) {
 148      // The theme is not yet available and a fallback is available.
 149      // Return the fallback immediately, specifying the Content-Length, then generate in the background.
 150      $css = file_get_contents($fallbacksheet);
 151      css_send_temporary_css($css);
 152  
 153      // The fallback content has now been sent.
 154      // There will be an attempt to generate the content, but it should not be served.
 155      // The Content-Length above means that the client will disregard it anyway.
 156      $sendaftergeneration = false;
 157  
 158      // There may be another client currently holding a lock and generating the stylesheet.
 159      // Use a very low lock timeout as the connection will be ended immediately afterwards.
 160      $locktimeout = 1;
 161  } else {
 162      // There is no fallback content to be issued here, therefore the generated content must be output.
 163      $sendaftergeneration = true;
 164  
 165      // Use a realistic lock timeout as the intention is to avoid lock contention.
 166      $locktimeout = rand(90, 120);
 167  }
 168  
 169  // Attempt to fetch the lock.
 170  $lockfactory = \core\lock\lock_config::get_lock_factory('core_theme_get_css_content');
 171  $lock = $lockfactory->get_lock($themename, $locktimeout);
 172  
 173  if ($sendaftergeneration || $lock) {
 174      // Either the lock was successful, or the lock was unsuccessful but the content *must* be sent.
 175  
 176      // The content does not exist locally.
 177      // Generate and save it.
 178      $candidatesheet = theme_styles_generate_and_store($theme, $rev, $themesubrev, $candidatedir);
 179  
 180      if ($lock) {
 181          $lock->release();
 182      }
 183  
 184      if ($sendaftergeneration) {
 185          if (!$cache) {
 186              // Do not pollute browser caches if invalid revision requested,
 187              // let's ignore legacy IE breakage here too.
 188              css_send_uncached_css(file_get_contents($candidatesheet));
 189  
 190          } else {
 191              // Real browsers - this is the expected result!
 192              css_send_cached_css($candidatesheet, $etag);
 193          }
 194      }
 195  }
 196  
 197  /**
 198   * Generate the theme CSS and store it.
 199   *
 200   * @param   theme_config    $theme The theme to be generated
 201   * @param   int             $rev The theme revision
 202   * @param   int             $themesubrev The theme sub-revision
 203   * @param   string          $candidatedir The directory that it should be stored in
 204   * @return  string          The path that the primary CSS was written to
 205   */
 206  function theme_styles_generate_and_store($theme, $rev, $themesubrev, $candidatedir) {
 207      global $CFG;
 208      require_once("{$CFG->libdir}/filelib.php");
 209  
 210      // Generate the content first.
 211      if (!$csscontent = $theme->get_css_cached_content()) {
 212          $csscontent = $theme->get_css_content();
 213          $theme->set_css_content_cache($csscontent);
 214      }
 215  
 216      if ($theme->get_rtl_mode()) {
 217          $type = "all-rtl";
 218      } else {
 219          $type = "all";
 220      }
 221  
 222      // Determine the candidatesheet path.
 223      $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $theme->use_svg_icons());
 224  
 225      // Store the CSS.
 226      css_store_css($theme, $candidatesheet, $csscontent);
 227  
 228      // Store the fallback CSS in the temp directory.
 229      // This file is used as a fallback when waiting for a theme to compile and is not versioned in any way.
 230      $fallbacksheet = make_temp_directory("theme/{$theme->name}")
 231          . "/"
 232          . theme_styles_get_filename($type, 0, $theme->use_svg_icons());
 233      css_store_css($theme, $fallbacksheet, $csscontent);
 234  
 235      // Delete older revisions from localcache.
 236      $themecachedirs = glob("{$CFG->localcachedir}/theme/*", GLOB_ONLYDIR);
 237      foreach ($themecachedirs as $localcachedir) {
 238          $cachedrev = [];
 239          preg_match("/\/theme\/([0-9]+)$/", $localcachedir, $cachedrev);
 240          $cachedrev = isset($cachedrev[1]) ? intval($cachedrev[1]) : 0;
 241          if ($cachedrev > 0 && $cachedrev < $rev) {
 242              fulldelete($localcachedir);
 243          }
 244      }
 245  
 246      // Delete older theme subrevision CSS from localcache.
 247      $subrevfiles = glob("{$CFG->localcachedir}/theme/{$rev}/{$theme->name}/css/*.css");
 248      foreach ($subrevfiles as $subrevfile) {
 249          $cachedsubrev = [];
 250          preg_match("/_([0-9]+)\.([0-9]+\.)?css$/", $subrevfile, $cachedsubrev);
 251          $cachedsubrev = isset($cachedsubrev[1]) ? intval($cachedsubrev[1]) : 0;
 252          if ($cachedsubrev > 0 && $cachedsubrev < $themesubrev) {
 253              fulldelete($subrevfile);
 254          }
 255      }
 256  
 257      return $candidatesheet;
 258  }
 259  
 260  /**
 261   * Fetch the preferred fallback content location if available.
 262   *
 263   * @param   theme_config    $theme The theme to be generated
 264   * @return  string          The path to the fallback sheet on disk
 265   */
 266  function theme_styles_fallback_content($theme) {
 267      global $CFG;
 268  
 269      if (!$theme->usefallback) {
 270          // This theme does not support fallbacks.
 271          return false;
 272      }
 273  
 274      $type = $theme->get_rtl_mode() ? 'all-rtl' : 'all';
 275      $filename = theme_styles_get_filename($type);
 276  
 277      $fallbacksheet = "{$CFG->tempdir}/theme/{$theme->name}/{$filename}";
 278      if (file_exists($fallbacksheet)) {
 279          return $fallbacksheet;
 280      }
 281  
 282      return false;
 283  }
 284  
 285  /**
 286   * Get the filename for the specified configuration.
 287   *
 288   * @param   string  $type The requested sheet type
 289   * @param   int     $themesubrev The theme sub-revision
 290   * @param   bool    $usesvg Whether SVGs are allowed
 291   * @return  string  The filename for this sheet
 292   */
 293  function theme_styles_get_filename($type, $themesubrev = 0, $usesvg = true) {
 294      $filename = $type;
 295      $filename .= ($themesubrev > 0) ? "_{$themesubrev}" : '';
 296      $filename .= $usesvg ? '' : '-nosvg';
 297  
 298      return "{$filename}.css";
 299  }
 300  
 301  /**
 302   * Determine the correct etag for the specified configuration.
 303   *
 304   * @param   string  $themename The name of the theme
 305   * @param   int     $rev The revision number
 306   * @param   string  $type The requested sheet type
 307   * @param   int     $themesubrev The theme sub-revision
 308   * @param   bool    $usesvg Whether SVGs are allowed
 309   * @return  string  The etag to use for this request
 310   */
 311  function theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg) {
 312      $etag = [$rev, $themename, $type, $themesubrev];
 313  
 314      if (!$usesvg) {
 315          $etag[] = 'nosvg';
 316      }
 317  
 318      return sha1(implode('/', $etag));
 319  }