Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * This file is responsible for serving the one huge CSS of each theme.

 *

 * @package   core

 * @copyright 2009 Petr Skoda (skodak)  {@link http://skodak.org}

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

// Disable moodle specific debug messages and any errors in output,

// comment out when debugging or better look into error log!

define('NO_DEBUG_DISPLAY', true);

define('ABORT_AFTER_CONFIG', true);

require('../config.php');

require_once($CFG->dirroot.'/lib/csslib.php');

if ($slashargument = min_get_slash_argument()) {

    $slashargument = ltrim($slashargument, '/');

    if (substr_count($slashargument, '/') < 2) {

        css_send_css_not_found();

    }

    if (strpos($slashargument, '_s/') === 0) {

        // Can't use SVG.

        $slashargument = substr($slashargument, 3);

        $usesvg = false;

    } else {

        $usesvg = true;

    }

    list($themename, $rev, $type) = explode('/', $slashargument, 3);

    $themename = min_clean_param($themename, 'SAFEDIR');

    $rev       = min_clean_param($rev, 'RAW');

    $type      = min_clean_param($type, 'SAFEDIR');

} else {

    $themename = min_optional_param('theme', 'standard', 'SAFEDIR');

    $rev       = min_optional_param('rev', 0, 'RAW');

    $type      = min_optional_param('type', 'all', 'SAFEDIR');

    $usesvg    = (bool)min_optional_param('svg', '1', 'INT');

}

// Check if we received a theme sub revision which allows us

// to handle local caching on a per theme basis.

$values = explode('_', $rev);

$rev = min_clean_param(array_shift($values), 'INT');

$themesubrev = array_shift($values);

if (!is_null($themesubrev)) {

    $themesubrev = min_clean_param($themesubrev, 'INT');

}

// Note: We only check validity of the revision number here, we do not check the theme sub-revision because this is

// not solely based on time.

if (!min_is_revision_valid_and_current($rev)) {

    // If the rev is invalid, normalise it to -1 to disable all caching.

    $rev = -1;

}

// Check that type fits into the expected values.

if (!in_array($type, ['all', 'all-rtl', 'editor', 'editor-rtl'])) {

    css_send_css_not_found();

}

if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {

    // The theme exists in standard location - ok.

} else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {

    // Alternative theme location contains this theme - ok.

} else {

    header('HTTP/1.0 404 not found');

    die('Theme was not found, sorry.');

}

$candidatedir = "$CFG->localcachedir/theme/$rev/$themename/css";

$candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg);

$etag = theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg);

if (file_exists($candidatesheet)) {

    if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {

        // We do not actually need to verify the etag value because our files

        // never change in cache because we increment the rev counter.

        css_send_unmodified(filemtime($candidatesheet), $etag);

    }

    css_send_cached_css($candidatesheet, $etag);

}

// Ok, now we need to start normal moodle script, we need to load all libs and $DB.

define('ABORT_AFTER_CONFIG_CANCEL', true);

define('NO_MOODLE_COOKIES', true); // Session not used here.

define('NO_UPGRADE_CHECK', true);  // Ignore upgrade check.

require("$CFG->dirroot/lib/setup.php");

$theme = theme_config::load($themename);

$theme->force_svg_use($usesvg);

$theme->set_rtl_mode(substr($type, -4) === '-rtl');

$themerev = theme_get_revision();

$currentthemesubrev = theme_get_sub_revision_for_theme($themename);

$cache = true;

// If the client is requesting a revision that doesn't match both

// the global theme revision and the theme specific revision then

// tell the browser not to cache this style sheet because it's

// likely being regenerated.

if ($themerev <= 0 or $themerev != $rev or $themesubrev != $currentthemesubrev) {

    $rev = $themerev;

    $themesubrev = $currentthemesubrev;

    $cache = false;

    $candidatedir = "$CFG->localcachedir/theme/$rev/$themename/css";

    $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $usesvg);

    $etag = theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg);

}

make_localcache_directory('theme', false);

if ($type === 'editor' || $type === 'editor-rtl') {

    $csscontent = $theme->get_css_content_editor();

    if ($cache) {

        css_store_css($theme, $candidatesheet, $csscontent);

        css_send_cached_css($candidatesheet, $etag);

    } else {

        css_send_uncached_css($csscontent);

    }

}

if (($fallbacksheet = theme_styles_fallback_content($theme)) && !$theme->has_css_cached_content()) {

    // The theme is not yet available and a fallback is available.

    // Return the fallback immediately, specifying the Content-Length, then generate in the background.

    $css = file_get_contents($fallbacksheet);

    css_send_temporary_css($css);

    // The fallback content has now been sent.

    // There will be an attempt to generate the content, but it should not be served.

    // The Content-Length above means that the client will disregard it anyway.

    $sendaftergeneration = false;

    // There may be another client currently holding a lock and generating the stylesheet.

    // Use a very low lock timeout as the connection will be ended immediately afterwards.

    $locktimeout = 1;

} else {

    // There is no fallback content to be issued here, therefore the generated content must be output.

    $sendaftergeneration = true;

    // Use a realistic lock timeout as the intention is to avoid lock contention.

    $locktimeout = rand(90, 120);

}

// Attempt to fetch the lock.

$lockfactory = \core\lock\lock_config::get_lock_factory('core_theme_get_css_content');

$lock = $lockfactory->get_lock($themename, $locktimeout);

if ($sendaftergeneration || $lock) {

    // Either the lock was successful, or the lock was unsuccessful but the content *must* be sent.

    // The content does not exist locally.

    // Generate and save it.

    $candidatesheet = theme_styles_generate_and_store($theme, $rev, $themesubrev, $candidatedir);

    if ($lock) {

        $lock->release();

    }

    if ($sendaftergeneration) {

        if (!$cache) {

            // Do not pollute browser caches if invalid revision requested,

            // let's ignore legacy IE breakage here too.

            css_send_uncached_css(file_get_contents($candidatesheet));

        } else {

            // Real browsers - this is the expected result!

            css_send_cached_css($candidatesheet, $etag);

        }

    }

}

/**

 * Generate the theme CSS and store it.

 *

 * @param   theme_config    $theme The theme to be generated

 * @param   int             $rev The theme revision

 * @param   int             $themesubrev The theme sub-revision

 * @param   string          $candidatedir The directory that it should be stored in

 * @return  string          The path that the primary CSS was written to

 */

function theme_styles_generate_and_store($theme, $rev, $themesubrev, $candidatedir) {

    global $CFG;

    require_once("{$CFG->libdir}/filelib.php");

    // Generate the content first.

    if (!$csscontent = $theme->get_css_cached_content()) {

        $csscontent = $theme->get_css_content();

        $theme->set_css_content_cache($csscontent);

    }

    if ($theme->get_rtl_mode()) {

        $type = "all-rtl";

    } else {

        $type = "all";

    }

    // Determine the candidatesheet path.

    $candidatesheet = "{$candidatedir}/" . theme_styles_get_filename($type, $themesubrev, $theme->use_svg_icons());

    // Store the CSS.

    css_store_css($theme, $candidatesheet, $csscontent);

    // Store the fallback CSS in the temp directory.

    // This file is used as a fallback when waiting for a theme to compile and is not versioned in any way.

    $fallbacksheet = make_temp_directory("theme/{$theme->name}")

        . "/"

        . theme_styles_get_filename($type, 0, $theme->use_svg_icons());

    css_store_css($theme, $fallbacksheet, $csscontent);

    // Delete older revisions from localcache.

    $themecachedirs = glob("{$CFG->localcachedir}/theme/*", GLOB_ONLYDIR);

    foreach ($themecachedirs as $localcachedir) {

        $cachedrev = [];

        preg_match("/\/theme\/([0-9]+)$/", $localcachedir, $cachedrev);

        $cachedrev = isset($cachedrev[1]) ? intval($cachedrev[1]) : 0;

        if ($cachedrev > 0 && $cachedrev < $rev) {

            fulldelete($localcachedir);

        }

    }

    // Delete older theme subrevision CSS from localcache.

    $subrevfiles = glob("{$CFG->localcachedir}/theme/{$rev}/{$theme->name}/css/*.css");

    foreach ($subrevfiles as $subrevfile) {

        $cachedsubrev = [];

        preg_match("/_([0-9]+)\.([0-9]+\.)?css$/", $subrevfile, $cachedsubrev);

        $cachedsubrev = isset($cachedsubrev[1]) ? intval($cachedsubrev[1]) : 0;

        if ($cachedsubrev > 0 && $cachedsubrev < $themesubrev) {

            fulldelete($subrevfile);

        }

    }

    return $candidatesheet;

}

/**

 * Fetch the preferred fallback content location if available.

 *

 * @param   theme_config    $theme The theme to be generated

 * @return  string          The path to the fallback sheet on disk

 */

function theme_styles_fallback_content($theme) {

    global $CFG;

    if (!$theme->usefallback) {

        // This theme does not support fallbacks.

        return false;

    }

    $type = $theme->get_rtl_mode() ? 'all-rtl' : 'all';

    $filename = theme_styles_get_filename($type);

    $fallbacksheet = "{$CFG->tempdir}/theme/{$theme->name}/{$filename}";

    if (file_exists($fallbacksheet)) {

        return $fallbacksheet;

    }

    return false;

}

/**

 * Get the filename for the specified configuration.

 *

 * @param   string  $type The requested sheet type

 * @param   int     $themesubrev The theme sub-revision

 * @param   bool    $usesvg Whether SVGs are allowed

 * @return  string  The filename for this sheet

 */

function theme_styles_get_filename($type, $themesubrev = 0, $usesvg = true) {

    $filename = $type;

    $filename .= ($themesubrev > 0) ? "_{$themesubrev}" : '';

    $filename .= $usesvg ? '' : '-nosvg';

    return "{$filename}.css";

}

/**

 * Determine the correct etag for the specified configuration.

 *

 * @param   string  $themename The name of the theme

 * @param   int     $rev The revision number

 * @param   string  $type The requested sheet type

 * @param   int     $themesubrev The theme sub-revision

 * @param   bool    $usesvg Whether SVGs are allowed

 * @return  string  The etag to use for this request

 */

function theme_styles_get_etag($themename, $rev, $type, $themesubrev, $usesvg) {

    $etag = [$rev, $themename, $type, $themesubrev];

    if (!$usesvg) {

        $etag[] = 'nosvg';

    }

    return sha1(implode('/', $etag));

}