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/>.

/**

 * @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.

            navigation_cache::destroy_volatile_caches();

            \core\session\manager::write_close();

        }

        // 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);

    }

}