Search moodle.org's
Developer Documentation

See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
<?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/>.

/**
 * @package moodlecore
 * @subpackage backup-controller
 * @copyright 2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/**
 * Class implementing the controller of any restore process
 *
 * This final class is in charge of controlling all the restore architecture, for any
 * type of backup.
 *
 * TODO: Finish phpdocs
 */
class restore_controller extends base_controller {

    protected $tempdir;   // Directory under $CFG->backuptempdir awaiting restore
    protected $restoreid; // Unique identificator for this restore

    protected $courseid; // courseid where restore is going to happen

    protected $type;   // Type of backup (activity, section, course)
    protected $format; // Format of backup (moodle, imscc)
    protected $interactive; // yes/no
    protected $mode;   // Purpose of the backup (default settings)
    protected $userid; // user id executing the restore
    protected $operation; // Type of operation (backup/restore)
    protected $target;    // Restoring to new/existing/current_adding/_deleting
    protected $samesite;  // Are we restoring to the same site where the backup was generated

    protected $status; // Current status of the controller (created, planned, configured...)
    protected $precheck;    // Results of the execution of restore prechecks

    protected $info;   // Information retrieved from backup contents
    /** @var restore_plan */
    protected $plan;   // Restore execution plan

    /**
     * Immediate/delayed execution type.
     * @var integer
     */
    protected $execution;
    protected $executiontime; // epoch time when we want the restore to be executed (requires cron to run)

    protected $checksum; // Cache @checksumable results for lighter @is_checksum_correct() uses

    /** @var int Number of restore_controllers that are currently executing */
    protected static $executing = 0;

    /**
     * Holds the relevant destination information for course copy operations.
     *
     * @var \stdClass.
     */
    protected $copy;

    /**
     * Constructor.
     *
     * If you specify a progress monitor, this will be used to report progress
     * while loading the plan, as well as for future use. (You can change it
     * for a different one later using set_progress.)
     *
     * @param string $tempdir Directory under $CFG->backuptempdir awaiting restore
     * @param int $courseid Course id where restore is going to happen
     * @param bool $interactive backup::INTERACTIVE_YES[true] or backup::INTERACTIVE_NO[false]
     * @param int $mode backup::MODE_[ GENERAL | HUB | IMPORT | SAMESITE ]
     * @param int $userid
     * @param int $target backup::TARGET_[ NEW_COURSE | CURRENT_ADDING | CURRENT_DELETING | EXISTING_ADDING | EXISTING_DELETING ]
     * @param \core\progress\base $progress Optional progress monitor
     * @param \stdClass $copydata Course copy data, required when in MODE_COPY
     * @param bool $releasesession Should release the session? backup::RELEASESESSION_YES or backup::RELEASESESSION_NO
     */
    public function __construct($tempdir, $courseid, $interactive, $mode, $userid, $target,
            \core\progress\base $progress = null, $releasesession = backup::RELEASESESSION_NO, ?\stdClass $copydata = null) {

        if ($mode == backup::MODE_COPY && is_null($copydata)) {
            throw new restore_controller_exception('cannot_instantiate_missing_copydata');
        }

        $this->copy = $copydata;
        $this->tempdir = $tempdir;
        $this->courseid = $courseid;
        $this->interactive = $interactive;
        $this->mode = $mode;
        $this->userid = $userid;
        $this->target = $target;
        $this->releasesession = $releasesession;

        // Apply some defaults
        $this->type = '';
        $this->format = backup::FORMAT_UNKNOWN;
        $this->operation = backup::OPERATION_RESTORE;
        $this->executiontime = 0;
        $this->samesite = false;
        $this->checksum = '';
        $this->precheck = null;

        // Apply current backup version and release if necessary
        backup_controller_dbops::apply_version_and_release();

        // Check courseid is correct
        restore_check::check_courseid($this->courseid);

        // Check user is correct
        restore_check::check_user($this->userid);

        // Calculate unique $restoreid
        $this->calculate_restoreid();

        // Default logger chain (based on interactive/execution)
        $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->restoreid);

        // Set execution based on backup mode.
        if ($mode == backup::MODE_ASYNC || $mode == backup::MODE_COPY) {
            $this->execution = backup::EXECUTION_DELAYED;
        } else {
            $this->execution = backup::EXECUTION_INMEDIATE;
        }

        // By default there is no progress reporter unless you specify one so it
        // can be used during loading of the plan.
        if ($progress) {
            $this->progress = $progress;
        } else {
            $this->progress = new \core\progress\none();
        }
        $this->progress->start_progress('Constructing restore_controller');

        // Instantiate the output_controller singleton and active it if interactive and immediate.
        $oc = output_controller::get_instance();
        if ($this->interactive == backup::INTERACTIVE_YES && $this->execution == backup::EXECUTION_INMEDIATE) {
            $oc->set_active(true);
        }

        $this->log('instantiating restore controller', backup::LOG_INFO, $this->restoreid);

        // Set initial status
        $this->set_status(backup::STATUS_CREATED);

        // Calculate original restore format
        $this->format = backup_general_helper::detect_backup_format($tempdir);

        // If format is not moodle2, set to conversion needed
        if ($this->format !== backup::FORMAT_MOODLE) {
            $this->set_status(backup::STATUS_REQUIRE_CONV);

        // Else, format is moodle2, load plan, apply security and set status based on interactivity
        } else {
            // Load plan
            $this->load_plan();

            // Apply all default settings (based on type/format/mode).
            $this->apply_defaults();

            // Perform all initial security checks and apply (2nd param) them to settings automatically
            restore_check::check_security($this, true);

            if ($this->interactive == backup::INTERACTIVE_YES) {
                $this->set_status(backup::STATUS_SETTING_UI);
            } else {
                $this->set_status(backup::STATUS_NEED_PRECHECK);
            }
        }

        // Tell progress monitor that we finished loading.
        $this->progress->end_progress();
    }

    /**
     * Clean structures used by the restore_controller
     *
     * This method clean various structures used by the restore_controller,
     * destroying them in an ordered way, so their memory will be gc properly
     * by PHP (mainly circular references).
     *
     * Note that, while it's not mandatory to execute this method, it's highly
     * recommended to do so, specially in scripts performing multiple operations
     * (like the automated backups) or the system will run out of memory after
     * a few dozens of backups)
     */
    public function destroy() {
        // Only need to destroy circulars under the plan. Delegate to it.
        $this->plan->destroy();
        // Loggers may have also chained references, destroy them. Also closing resources when needed.
        $this->logger->destroy();
    }

    public function finish_ui() {
        if ($this->status != backup::STATUS_SETTING_UI) {
            throw new restore_controller_exception('cannot_finish_ui_if_not_setting_ui');
        }
        $this->set_status(backup::STATUS_NEED_PRECHECK);
    }

    public function process_ui_event() {

        // Perform security checks throwing exceptions (2nd param) if something is wrong
        restore_check::check_security($this, false);
    }

    public function set_status($status) {
        // Note: never save_controller() with the object info after STATUS_EXECUTING or the whole controller,
        // containing all the steps will be sent to DB. 100% (monster) useless.
        $this->log('setting controller status to', backup::LOG_DEBUG, $status);
        // TODO: Check it's a correct status.
        $this->status = $status;
        // Ensure that, once set to backup::STATUS_AWAITING | STATUS_NEED_PRECHECK, controller is stored in DB.
        // Also save if executing so we can better track progress.
        if ($status == backup::STATUS_AWAITING || $status == backup::STATUS_NEED_PRECHECK || $status == backup::STATUS_EXECUTING) {
            $this->save_controller();
            $tbc = self::load_controller($this->restoreid);
            $this->logger = $tbc->logger; // wakeup loggers
            $tbc->plan->destroy(); // Clean plan controller structures, keeping logger alive.

        } else if ($status == backup::STATUS_FINISHED_OK) {
            // If the operation has ended without error (backup::STATUS_FINISHED_OK)
            // proceed by cleaning the object from database. MDL-29262.
            $this->save_controller(false, true);
        } else if ($status == backup::STATUS_FINISHED_ERR) {
            // If the operation has ended with an error save the controller
            // preserving the object in the database. We may want it for debugging.
            $this->save_controller();
        }
    }

    public function set_execution($execution, $executiontime = 0) {
        $this->log('setting controller execution', backup::LOG_DEBUG);
        // TODO: Check valid execution mode.
        // TODO: Check time in future.
        // TODO: Check time = 0 if immediate.
        $this->execution = $execution;
        $this->executiontime = $executiontime;

        // Default logger chain (based on interactive/execution)
        $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->restoreid);
    }

// checksumable interface methods

    public function calculate_checksum() {
        // Reset current checksum to take it out from calculations!
        $this->checksum = '';
        // Init checksum
        $tempchecksum = md5('tempdir-'    . $this->tempdir .
                            'restoreid-'  . $this->restoreid .
                            'courseid-'   . $this->courseid .
                            'type-'       . $this->type .
                            'format-'     . $this->format .
                            'interactive-'. $this->interactive .
                            'mode-'       . $this->mode .
                            'userid-'     . $this->userid .
                            'target-'     . $this->target .
                            'samesite-'   . $this->samesite .
                            'operation-'  . $this->operation .
                            'status-'     . $this->status .
                            'precheck-'   . backup_general_helper::array_checksum_recursive(array($this->precheck)) .
                            'execution-'  . $this->execution .
                            'plan-'       . backup_general_helper::array_checksum_recursive(array($this->plan)) .
                            'info-'       . backup_general_helper::array_checksum_recursive(array($this->info)) .
                            'logger-'     . backup_general_helper::array_checksum_recursive(array($this->logger)));
        $this->log('calculating controller checksum', backup::LOG_DEBUG, $tempchecksum);
        return $tempchecksum;
    }

    public function is_checksum_correct($checksum) {
        return $this->checksum === $checksum;
    }

    public function get_tempdir() {
        return $this->tempdir;
    }

    public function get_restoreid() {
        return $this->restoreid;
    }

    public function get_type() {
        return $this->type;
    }

    public function get_operation() {
        return $this->operation;
    }

    public function get_courseid() {
        return $this->courseid;
    }

    public function get_format() {
        return $this->format;
    }

    public function get_interactive() {
        return $this->interactive;
    }

    public function get_mode() {
        return $this->mode;
    }

    public function get_userid() {
        return $this->userid;
    }

    public function get_target() {
        return $this->target;
    }

    public function is_samesite() {
        return $this->samesite;
    }

    public function get_status() {
        return $this->status;
    }

    public function get_execution() {
        return $this->execution;
    }

    public function get_executiontime() {
        return $this->executiontime;
    }

    /**
     * Returns the restore plan
     * @return restore_plan
     */
    public function get_plan() {
        return $this->plan;
    }
    /**
     * Gets the value for the requested setting
     *
     * @param string $name
     * @param bool $default
     * @return mixed
     */
    public function get_setting_value($name, $default = false) {
        try {
            return $this->get_plan()->get_setting($name)->get_value();
        } catch (Exception $e) {
            debugging('Failed to find the setting: '.$name, DEBUG_DEVELOPER);
            return $default;
        }
    }

    /**
     * For debug only. Get a simple test display of all the settings.
     *
     * @return string
     */
    public function debug_display_all_settings_values(): string {
        return $this->get_plan()->debug_display_all_settings_values();
    }

    public function get_info() {
        return $this->info;
    }

    public function execute_plan() {
        // Basic/initial prevention against time/memory limits
        core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
        raise_memory_limit(MEMORY_EXTRA);

        // Release the session so other tabs in the same session are not blocked.
        if ($this->get_releasesession() === backup::RELEASESESSION_YES) {
> // Preemptively reset the navcache before closing, so it remains the same on shutdown. \core\session\manager::write_close(); > navigation_cache::destroy_volatile_caches(); } >
// Do course cleanup precheck, if required. This was originally in restore_ui. Moved to handle async backup/restore. if ($this->get_target() == backup::TARGET_CURRENT_DELETING || $this->get_target() == backup::TARGET_EXISTING_DELETING) { $options = array(); $options['keep_roles_and_enrolments'] = $this->get_setting_value('keep_roles_and_enrolments'); $options['keep_groups_and_groupings'] = $this->get_setting_value('keep_groups_and_groupings'); $options['userid'] = $this->userid; restore_dbops::delete_course_content($this->get_courseid(), $options); } // If this is not a course restore or single activity restore (e.g. duplicate), inform the plan we are not // including all the activities for sure. This will affect any // task/step executed conditionally to stop processing information // for section and activity restore. MDL-28180. if ($this->get_type() !== backup::TYPE_1COURSE && $this->get_type() !== backup::TYPE_1ACTIVITY) { $this->log('notifying plan about excluded activities by type', backup::LOG_DEBUG); $this->plan->set_excluding_activities(); } self::$executing++; try { $this->plan->execute(); } catch (Exception $e) { self::$executing--; throw $e; } self::$executing--; } /** * Checks whether restore is currently executing. Certain parts of code that * is called during restore, but not directly part of the restore system, may * need to behave differently during restore (e.g. do not bother resetting a * cache because we know it will be reset at end of operation). * * @return bool True if any restore is currently executing */ public static function is_executing() { return self::$executing > 0; } /** * Execute the restore prechecks to detect any problem before proceed with restore * * This function checks various parts of the restore (versions, users, roles...) * returning true if everything was ok or false if any warning/error was detected. * Any warning/error is returned by the get_precheck_results() method. * Note: if any problem is found it will, automatically, drop all the restore temp * tables as far as the next step is to inform about the warning/errors. If no problem * is found, then default behaviour is to keep the temp tables so, in the same request * restore will be executed, saving a lot of checks to be executed again. * Note: If for any reason (UI to show after prechecks...) you want to force temp tables * to be dropped always, you can pass true to the $droptemptablesafter parameter */ public function execute_precheck($droptemptablesafter = false) { if (is_array($this->precheck)) { throw new restore_controller_exception('precheck_alredy_executed', $this->status); } if ($this->status != backup::STATUS_NEED_PRECHECK) { throw new restore_controller_exception('cannot_precheck_wrong_status', $this->status); } // Basic/initial prevention against time/memory limits core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted raise_memory_limit(MEMORY_EXTRA); $this->precheck = restore_prechecks_helper::execute_prechecks($this, $droptemptablesafter); if (!array_key_exists('errors', $this->precheck)) { // No errors, can be executed $this->set_status(backup::STATUS_AWAITING); } if (empty($this->precheck)) { // No errors nor warnings, return true return true; } return false; } public function get_results() { return $this->plan->get_results(); } /** * Returns true if the prechecks have been executed * @return bool */ public function precheck_executed() { return (is_array($this->precheck)); } public function get_precheck_results() { if (!is_array($this->precheck)) { throw new restore_controller_exception('precheck_not_executed'); } return $this->precheck; } /** * Save controller information * * @param bool $includeobj to decide if the object itself must be updated (true) or no (false) * @param bool $cleanobj to decide if the object itself must be cleaned (true) or no (false) */ public function save_controller($includeobj = true, $cleanobj = false) { // Going to save controller to persistent storage, calculate checksum for later checks and save it // TODO: flag the controller as NA. Any operation on it should be forbidden util loaded back $this->log('saving controller to db', backup::LOG_DEBUG); if ($includeobj ) { // Only calculate checksum if we are going to include the object. $this->checksum = $this->calculate_checksum(); } restore_controller_dbops::save_controller($this, $this->checksum, $includeobj, $cleanobj); } public static function load_controller($restoreid) { // Load controller from persistent storage // TODO: flag the controller as available. Operations on it can continue $controller = restore_controller_dbops::load_controller($restoreid); $controller->log('loading controller from db', backup::LOG_DEBUG); return $controller; } /** * class method to provide pseudo random unique "correct" tempdir names */ public static function get_tempdir_name($courseid = 0, $userid = 0) { // Current epoch time + courseid + userid + random bits return md5(time() . '-' . $courseid . '-'. $userid . '-'. random_string(20)); } /** * Converts from current format to backup::MOODLE format */ public function convert() { global $CFG; require_once($CFG->dirroot . '/backup/util/helper/convert_helper.class.php'); // Basic/initial prevention against time/memory limits core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted raise_memory_limit(MEMORY_EXTRA); $this->progress->start_progress('Backup format conversion'); if ($this->status != backup::STATUS_REQUIRE_CONV) { throw new restore_controller_exception('cannot_convert_not_required_status'); } $this->log('backup format conversion required', backup::LOG_INFO); // Run conversion to the proper format if (!convert_helper::to_moodle2_format($this->get_tempdir(), $this->format, $this->get_logger())) { // todo - unable to find the conversion path, what to do now? // throwing the exception as a temporary solution throw new restore_controller_exception('unable_to_find_conversion_path'); } $this->log('backup format conversion successful', backup::LOG_INFO); // If no exceptions were thrown, then we are in the proper format $this->format = backup::FORMAT_MOODLE; // Load plan, apply security and set status based on interactivity $this->load_plan(); // Perform all initial security checks and apply (2nd param) them to settings automatically restore_check::check_security($this, true); if ($this->interactive == backup::INTERACTIVE_YES) { $this->set_status(backup::STATUS_SETTING_UI); } else { $this->set_status(backup::STATUS_NEED_PRECHECK); } $this->progress->end_progress(); } /** * Do the necessary copy preparation actions. * This method should only be called once the backup of a copy operation is completed. * * @throws restore_controller_exception */ public function prepare_copy(): void { // Check that we are in the correct mode. if ($this->mode != backup::MODE_COPY) { throw new restore_controller_exception('cannot_prepare_copy_wrong_mode'); } $this->progress->start_progress('Prepare Copy'); // If no exceptions were thrown, then we are in the proper format. $this->format = backup::FORMAT_MOODLE; // Load plan, apply security and set status based on interactivity. $this->load_plan(); $this->set_status(backup::STATUS_NEED_PRECHECK); $this->progress->end_progress(); } /** * Get the course copy data. * * @return \stdClass */ public function get_copy(): \stdClass { if ($this->mode != backup::MODE_COPY) { throw new restore_controller_exception('cannot_get_copy_wrong_mode'); } return $this->copy; } // Protected API starts here protected function calculate_restoreid() { // Current epoch time + tempdir + courseid + interactive + mode + userid + target + operation + random bits $this->restoreid = md5(time() . '-' . $this->tempdir . '-' . $this->courseid . '-'. $this->interactive . '-' . $this->mode . '-' . $this->userid . '-'. $this->target . '-' . $this->operation . '-' . random_string(20)); } protected function load_plan() { // First of all, we need to introspect the moodle_backup.xml file // in order to detect all the required stuff. So, create the // monster $info structure where everything will be defined $this->log('loading backup info', backup::LOG_DEBUG); $this->info = backup_general_helper::get_backup_information($this->tempdir); // Set the controller type to the one found in the information $this->type = $this->info->type; // Set the controller samesite flag as needed $this->samesite = backup_general_helper::backup_is_samesite($this->info); // Now we load the plan that will be configured following the // information provided by the $info $this->log('loading controller plan', backup::LOG_DEBUG); $this->plan = new restore_plan($this); $this->plan->build(); // Build plan for this controller $this->set_status(backup::STATUS_PLANNED); } /** * Apply defaults from the global admin settings */ protected function apply_defaults() { $this->log('applying restore defaults', backup::LOG_DEBUG); restore_controller_dbops::apply_config_defaults($this); $this->set_status(backup::STATUS_CONFIGURED); } } /* * Exception class used by all the @restore_controller stuff */ class restore_controller_exception extends backup_exception { public function __construct($errorcode, $a=NULL, $debuginfo=null) { parent::__construct($errorcode, $a, $debuginfo); } }