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-dbops

 * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}

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

 */

/**

 * Non instantiable helper class providing DB support to the @backup_controller

 *

 * This class contains various static methods available for all the DB operations

 * performed by the backup_controller class

 *

 * TODO: Finish phpdocs

 */

abstract class backup_controller_dbops extends backup_dbops {

    /**

     * @var string Backup id for cached backup_includes_files result.

     */

    protected static $includesfilescachebackupid;

    /**

     * @var int Cached backup_includes_files result

     */

    protected static $includesfilescache;

    /**

     * Send one backup controller to DB

     *

     * @param backup_controller $controller controller to send to DB

     * @param string $checksum hash of the controller to be checked

     * @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)

     * @return int id of the controller record in the DB

     * @throws backup_controller_exception|backup_dbops_exception

     */

    public static function save_controller($controller, $checksum, $includeobj = true, $cleanobj = false) {

        global $DB;

        // Check we are going to save one backup_controller

        if (! $controller instanceof backup_controller) {

            throw new backup_controller_exception('backup_controller_expected');

        }

        // Check checksum is ok. Only if we are including object info. Sounds silly but it isn't ;-).

        if ($includeobj and !$controller->is_checksum_correct($checksum)) {

            throw new backup_dbops_exception('backup_controller_dbops_saving_checksum_mismatch');

        }

        // Cannot request to $includeobj and $cleanobj at the same time.

        if ($includeobj and $cleanobj) {

            throw new backup_dbops_exception('backup_controller_dbops_saving_cannot_include_and_delete');

        }

        // Get all the columns

        $rec = new stdclass();

        $rec->backupid     = $controller->get_backupid();

        $rec->operation    = $controller->get_operation();

        $rec->type         = $controller->get_type();

        $rec->itemid       = $controller->get_id();

        $rec->format       = $controller->get_format();

        $rec->interactive  = $controller->get_interactive();

        $rec->purpose      = $controller->get_mode();

        $rec->userid       = $controller->get_userid();

        $rec->status       = $controller->get_status();

        $rec->execution    = $controller->get_execution();

        $rec->executiontime= $controller->get_executiontime();

        $rec->checksum     = $checksum;

        // Serialize information

        if ($includeobj) {

            $rec->controller = base64_encode(serialize($controller));

        } else if ($cleanobj) {

            $rec->controller = '';

        }

        // Send it to DB

        if ($recexists = $DB->get_record('backup_controllers', array('backupid' => $rec->backupid))) {

            $rec->id = $recexists->id;

            $rec->timemodified = time();

            $DB->update_record('backup_controllers', $rec);

        } else {

            $rec->timecreated = time();

            $rec->timemodified = 0;

            $rec->id = $DB->insert_record('backup_controllers', $rec);

        }

        return $rec->id;

    }

    public static function load_controller($backupid) {

        global $DB;

        if (! $controllerrec = $DB->get_record('backup_controllers', array('backupid' => $backupid))) {

            throw new backup_dbops_exception('backup_controller_dbops_nonexisting');

        }

        $controller = unserialize(base64_decode($controllerrec->controller));

        if (!is_object($controller)) {

            // The controller field of the table did not contain a serialized object.

            // It is made empty after it has been used successfully, it is likely that

            // the user has pressed the browser back button at some point.

            throw new backup_dbops_exception('backup_controller_dbops_loading_invalid_controller');

        }

        // Check checksum is ok. Sounds silly but it isn't ;-)

        if (!$controller->is_checksum_correct($controllerrec->checksum)) {

            throw new backup_dbops_exception('backup_controller_dbops_loading_checksum_mismatch');

        }

        return $controller;

    }

    public static function create_backup_ids_temp_table($backupid) {

        global $CFG, $DB;

        $dbman = $DB->get_manager(); // We are going to use database_manager services

        $xmldb_table = new xmldb_table('backup_ids_temp');

        $xmldb_table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);

        // Set default backupid (not needed but this enforce any missing backupid). That's hackery in action!

        $xmldb_table->add_field('backupid', XMLDB_TYPE_CHAR, 32, null, XMLDB_NOTNULL, null, $backupid);

        $xmldb_table->add_field('itemname', XMLDB_TYPE_CHAR, 160, null, XMLDB_NOTNULL, null, null);

        $xmldb_table->add_field('itemid', XMLDB_TYPE_INTEGER, 10, null, XMLDB_NOTNULL, null, null);

        $xmldb_table->add_field('newitemid', XMLDB_TYPE_INTEGER, 10, null, XMLDB_NOTNULL, null, '0');

        $xmldb_table->add_field('parentitemid', XMLDB_TYPE_INTEGER, 10, null, null, null, null);

        $xmldb_table->add_field('info', XMLDB_TYPE_TEXT, null, null, null, null, null);

        $xmldb_table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));

        $xmldb_table->add_key('backupid_itemname_itemid_uk', XMLDB_KEY_UNIQUE, array('backupid','itemname','itemid'));

        $xmldb_table->add_index('backupid_parentitemid_ix', XMLDB_INDEX_NOTUNIQUE, array('backupid','itemname','parentitemid'));

        $xmldb_table->add_index('backupid_itemname_newitemid_ix', XMLDB_INDEX_NOTUNIQUE, array('backupid','itemname','newitemid'));

        $dbman->create_temp_table($xmldb_table); // And create it

    }

    public static function create_backup_files_temp_table($backupid) {

        global $CFG, $DB;

        $dbman = $DB->get_manager(); // We are going to use database_manager services

        $xmldb_table = new xmldb_table('backup_files_temp');

        $xmldb_table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);

        // Set default backupid (not needed but this enforce any missing backupid). That's hackery in action!

        $xmldb_table->add_field('backupid', XMLDB_TYPE_CHAR, 32, null, XMLDB_NOTNULL, null, $backupid);

        $xmldb_table->add_field('contextid', XMLDB_TYPE_INTEGER, 10, null, XMLDB_NOTNULL, null, null);

        $xmldb_table->add_field('component', XMLDB_TYPE_CHAR, 100, null, XMLDB_NOTNULL, null, null);

        $xmldb_table->add_field('filearea', XMLDB_TYPE_CHAR, 50, null, XMLDB_NOTNULL, null, null);

        $xmldb_table->add_field('itemid', XMLDB_TYPE_INTEGER, 10, null, XMLDB_NOTNULL, null, null);

        $xmldb_table->add_field('info', XMLDB_TYPE_TEXT, null, null, null, null, null);

        $xmldb_table->add_field('newcontextid', XMLDB_TYPE_INTEGER, 10, null, null, null, null);

        $xmldb_table->add_field('newitemid', XMLDB_TYPE_INTEGER, 10, null, null, null, null);

        $xmldb_table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));

        $xmldb_table->add_index('backupid_contextid_component_filearea_itemid_ix', XMLDB_INDEX_NOTUNIQUE, array('backupid','contextid','component','filearea','itemid'));

        $dbman->create_temp_table($xmldb_table); // And create it

    }

    public static function drop_backup_ids_temp_table($backupid) {

        global $DB;

        $dbman = $DB->get_manager(); // We are going to use database_manager services

        $targettablename = 'backup_ids_temp';

        if ($dbman->table_exists($targettablename)) {

            $table = new xmldb_table($targettablename);

            $dbman->drop_table($table); // And drop it

        }

    }

    /**

     * Decode the info field from backup_ids_temp or backup_files_temp.

     *

     * @param mixed $info The info field data to decode, may be an object or a simple integer.

     * @return mixed The decoded information.  For simple types it returns, for complex ones we decode.

     */

    public static function decode_backup_temp_info($info) {

        // We encode all data except null.

        if ($info != null) {

            return unserialize(gzuncompress(base64_decode($info)));

        }

        return $info;

    }

    /**

     * Encode the info field for backup_ids_temp or backup_files_temp.

     *

     * @param mixed $info string The info field data to encode.

     * @return string An encoded string of data or null if the input is null.

     */

    public static function encode_backup_temp_info($info) {

        // We encode if there is any information to keep the translations simpler.

        if ($info != null) {

            // We compress if possible. It reduces db, network and memory storage. The saving is greater than CPU compression cost.

            // Compression level 1 is chosen has it produces good compression with the smallest possible overhead, see MDL-40618.

            return base64_encode(gzcompress(serialize($info), 1));

        }

        return $info;

    }

    /**

     * Given one type and id from controller, return the corresponding courseid

     */

    public static function get_courseid_from_type_id($type, $id) {

        global $DB;

        if ($type == backup::TYPE_1COURSE) {

            return $id; // id is the course id

        } else if ($type == backup::TYPE_1SECTION) {

            if (! $courseid = $DB->get_field('course_sections', 'course', array('id' => $id))) {

                throw new backup_dbops_exception('course_not_found_for_section', $id);

            }

            return $courseid;

        } else if ($type == backup::TYPE_1ACTIVITY) {

            if (! $courseid = $DB->get_field('course_modules', 'course', array('id' => $id))) {

                throw new backup_dbops_exception('course_not_found_for_moduleid', $id);

            }

            return $courseid;

        }

    }

    /**

     * Given one activity task, return the activity information and related settings

     * Used by get_moodle_backup_information()

     */

    private static function get_activity_backup_information($task) {

        $contentinfo = array(

            'moduleid'   => $task->get_moduleid(),

            'sectionid'  => $task->get_sectionid(),

            'modulename' => $task->get_modulename(),

            'title'      => $task->get_name(),

            'directory'  => 'activities/' . $task->get_modulename() . '_' . $task->get_moduleid());

        // Now get activity settings

        // Calculate prefix to find valid settings

        $prefix = basename($contentinfo['directory']);

        $settingsinfo = array();

        foreach ($task->get_settings() as $setting) {

            // Discard ones without valid prefix

            if (strpos($setting->get_name(), $prefix) !== 0) {

                continue;

            }

            // Validate level is correct (activity)

            if ($setting->get_level() != backup_setting::ACTIVITY_LEVEL) {

                throw new backup_controller_exception('setting_not_activity_level', $setting);

            }

            $settinginfo = array(

                'level'    => 'activity',

                'activity' => $prefix,

                'name'     => $setting->get_name(),

                'value'    => $setting->get_value());

            $settingsinfo[$setting->get_name()] = (object)$settinginfo;

        }

        return array($contentinfo, $settingsinfo);

    }

    /**

     * Given one section task, return the section information and related settings

     * Used by get_moodle_backup_information()

     */

    private static function get_section_backup_information($task) {

        $contentinfo = array(

            'sectionid'  => $task->get_sectionid(),

            'title'      => $task->get_name(),

            'directory'  => 'sections/' . 'section_' . $task->get_sectionid());

        // Now get section settings

        // Calculate prefix to find valid settings

        $prefix = basename($contentinfo['directory']);

        $settingsinfo = array();

        foreach ($task->get_settings() as $setting) {

            // Discard ones without valid prefix

            if (strpos($setting->get_name(), $prefix) !== 0) {

                continue;

            }

            // Validate level is correct (section)

            if ($setting->get_level() != backup_setting::SECTION_LEVEL) {

                throw new backup_controller_exception('setting_not_section_level', $setting);

            }

            $settinginfo = array(

                'level'    => 'section',

                'section'  => $prefix,

                'name'     => $setting->get_name(),

                'value'    => $setting->get_value());

            $settingsinfo[$setting->get_name()] = (object)$settinginfo;

        }

        return array($contentinfo, $settingsinfo);

    }

    /**

     * Given one course task, return the course information and related settings

     * Used by get_moodle_backup_information()

     */

    private static function get_course_backup_information($task) {

        $contentinfo = array(

            'courseid'   => $task->get_courseid(),

            'title'      => $task->get_name(),

            'directory'  => 'course');

        // Now get course settings

        // Calculate prefix to find valid settings

        $prefix = basename($contentinfo['directory']);

        $settingsinfo = array();

        foreach ($task->get_settings() as $setting) {

            // Discard ones without valid prefix

            if (strpos($setting->get_name(), $prefix) !== 0) {

                continue;

            }

            // Validate level is correct (course)

            if ($setting->get_level() != backup_setting::COURSE_LEVEL) {

                throw new backup_controller_exception('setting_not_course_level', $setting);

            }

            $settinginfo = array(

                'level'    => 'course',

                'name'     => $setting->get_name(),

                'value'    => $setting->get_value());

            $settingsinfo[$setting->get_name()] = (object)$settinginfo;

        }

        return array($contentinfo, $settingsinfo);

    }

    /**

     * Given one root task, return the course information and related settings

     * Used by get_moodle_backup_information()

     */

    private static function get_root_backup_information($task) {

        // Now get root settings

        $settingsinfo = array();

        foreach ($task->get_settings() as $setting) {

            // Validate level is correct (root)

            if ($setting->get_level() != backup_setting::ROOT_LEVEL) {

                throw new backup_controller_exception('setting_not_root_level', $setting);

            }

            $settinginfo = array(

                'level'    => 'root',

                'name'     => $setting->get_name(),

                'value'    => $setting->get_value());

            $settingsinfo[$setting->get_name()] = (object)$settinginfo;

        }

        return array(null, $settingsinfo);

    }

    /**

     * Get details information for main moodle_backup.xml file, extracting it from

     * the specified controller.

     *

     * If you specify the progress monitor, this will start a new progress section

     * to track progress in processing (in case this task takes a long time).

     *

     * @param string $backupid Backup ID

     * @param \core\progress\base $progress Optional progress monitor

     */

    public static function get_moodle_backup_information($backupid,

            \core\progress\base $progress = null) {

        // Start tracking progress if required (for load_controller).

        if ($progress) {

            $progress->start_progress('get_moodle_backup_information', 2);

        }

        $detailsinfo = array(); // Information details

        $contentsinfo= array(); // Information about backup contents

        $settingsinfo= array(); // Information about backup settings

        $bc = self::load_controller($backupid); // Load controller

        // Note that we have loaded controller.

        if ($progress) {

            $progress->progress(1);

        }

        // Details info

        $detailsinfo['id'] = $bc->get_id();

        $detailsinfo['backup_id'] = $bc->get_backupid();

        $detailsinfo['type'] = $bc->get_type();

        $detailsinfo['format'] = $bc->get_format();

        $detailsinfo['interactive'] = $bc->get_interactive();

        $detailsinfo['mode'] = $bc->get_mode();

        $detailsinfo['execution'] = $bc->get_execution();

        $detailsinfo['executiontime'] = $bc->get_executiontime();

        $detailsinfo['userid'] = $bc->get_userid();

        $detailsinfo['courseid'] = $bc->get_courseid();

        // Init content placeholders

        $contentsinfo['activities'] = array();

        $contentsinfo['sections']   = array();

        $contentsinfo['course']     = array();

        // Get tasks and start nested progress.

        $tasks = $bc->get_plan()->get_tasks();

        if ($progress) {

            $progress->start_progress('get_moodle_backup_information', count($tasks));

            $done = 1;

        }

        // Contents info (extract information from tasks)

        foreach ($tasks as $task) {

            if ($task instanceof backup_activity_task) { // Activity task

                if ($task->get_setting_value('included')) { // Only return info about included activities

                    list($contentinfo, $settings) = self::get_activity_backup_information($task);

                    $contentsinfo['activities'][] = $contentinfo;

                    $settingsinfo = array_merge($settingsinfo, $settings);

                }

            } else if ($task instanceof backup_section_task) { // Section task

                if ($task->get_setting_value('included')) { // Only return info about included sections

                    list($contentinfo, $settings) = self::get_section_backup_information($task);

                    $contentsinfo['sections'][] = $contentinfo;

                    $settingsinfo = array_merge($settingsinfo, $settings);

                }

            } else if ($task instanceof backup_course_task) { // Course task

                list($contentinfo, $settings) = self::get_course_backup_information($task);

                $contentsinfo['course'][] = $contentinfo;

                $settingsinfo = array_merge($settingsinfo, $settings);

            } else if ($task instanceof backup_root_task) { // Root task

                list($contentinfo, $settings) = self::get_root_backup_information($task);

                $settingsinfo = array_merge($settingsinfo, $settings);

            }

            // Report task handled.

            if ($progress) {

                $progress->progress($done++);

            }

        }

        $bc->destroy(); // Always need to destroy controller to handle circular references

        // Finish progress reporting.

        if ($progress) {

            $progress->end_progress();

            $progress->end_progress();

        }

        return array(array((object)$detailsinfo), $contentsinfo, $settingsinfo);

    }

    /**

     * Update CFG->backup_version and CFG->backup_release if change in

     * version is detected.

     */

    public static function apply_version_and_release() {

        global $CFG;

        if ($CFG->backup_version < backup::VERSION) {

            set_config('backup_version', backup::VERSION);

            set_config('backup_release', backup::RELEASE);

        }

    }

    /**

     * Given the backupid, detect if the backup includes "mnet" remote users or no

     */

    public static function backup_includes_mnet_remote_users($backupid) {

        global $CFG, $DB;

        $sql = "SELECT COUNT(*)

                  FROM {backup_ids_temp} b

                  JOIN {user} u ON u.id = b.itemid

                 WHERE b.backupid = ?

                   AND b.itemname = 'userfinal'

                   AND u.mnethostid != ?";

        $count = $DB->count_records_sql($sql, array($backupid, $CFG->mnet_localhost_id));

        return (int)(bool)$count;

    }

    /**

     * Given the backupid, determine whether this backup should include

     * files from the moodle file storage system.

     *

     * @param string $backupid The ID of the backup.

     * @return int Indicates whether files should be included in backups.

     */

    public static function backup_includes_files($backupid) {

        // This function is called repeatedly in a backup with many files.

        // Loading the controller is a nontrivial operation (in a large test

        // backup it took 0.3 seconds), so we do a temporary cache of it within

        // this request.

        if (self::$includesfilescachebackupid === $backupid) {

            return self::$includesfilescache;

        }

        // Load controller, get value, then destroy controller and return result.

        self::$includesfilescachebackupid = $backupid;

        $bc = self::load_controller($backupid);

        self::$includesfilescache = $bc->get_include_files();

        $bc->destroy();

        return self::$includesfilescache;

    }

    /**

     * Given the backupid, detect if the backup contains references to external contents

     *

     * @copyright 2012 Dongsheng Cai {@link http://dongsheng.org}

     * @return int

     */

    public static function backup_includes_file_references($backupid) {

        global $CFG, $DB;

        $sql = "SELECT count(r.repositoryid)

                  FROM {files} f

                  LEFT JOIN {files_reference} r

                       ON r.id = f.referencefileid

                  JOIN {backup_ids_temp} bi

                       ON f.id = bi.itemid

                 WHERE bi.backupid = ?

                       AND bi.itemname = 'filefinal'";

        $count = $DB->count_records_sql($sql, array($backupid));

        return (int)(bool)$count;

    }

    /**

     * Given the courseid, return some course related information we want to transport

     *

     * @param int $course the id of the course this backup belongs to

     */

    public static function backup_get_original_course_info($courseid) {

        global $DB;

        return $DB->get_record('course', array('id' => $courseid), 'fullname, shortname, startdate, enddate, format');

    }

    /**

     * Sets the default values for the settings in a backup operation

     *

     * Based on the mode of the backup it will load proper defaults

     * using {@link apply_admin_config_defaults}.

     *

     * @param backup_controller $controller

     */

    public static function apply_config_defaults(backup_controller $controller) {

        // Based on the mode of the backup (general, automated, import, hub...)

        // decide the action to perform to get defaults loaded

        $mode = $controller->get_mode();

        switch ($mode) {

            case backup::MODE_GENERAL:

            case backup::MODE_ASYNC:

                // Load the general defaults

                $settings = array(

                        'backup_general_users'              => 'users',

                        'backup_general_anonymize'          => 'anonymize',

                        'backup_general_role_assignments'   => 'role_assignments',

                        'backup_general_activities'         => 'activities',

                        'backup_general_blocks'             => 'blocks',

                        'backup_general_filters'            => 'filters',

                        'backup_general_comments'           => 'comments',

                        'backup_general_badges'             => 'badges',

                        'backup_general_calendarevents'     => 'calendarevents',

                        'backup_general_userscompletion'    => 'userscompletion',

                        'backup_general_logs'               => 'logs',

                        'backup_general_histories'          => 'grade_histories',

                        'backup_general_questionbank'       => 'questionbank',

                        'backup_general_groups'             => 'groups',

                        'backup_general_competencies'       => 'competencies',

                        'backup_general_contentbankcontent' => 'contentbankcontent',

                        'backup_general_xapistate'          => 'xapistate',

                        'backup_general_legacyfiles'        => 'legacyfiles'

                );

                self::apply_admin_config_defaults($controller, $settings, true);

                break;

            case backup::MODE_IMPORT:

                // Load the import defaults.

                $settings = array(

                        'backup_import_activities'         => 'activities',

                        'backup_import_blocks'             => 'blocks',

                        'backup_import_filters'            => 'filters',

                        'backup_import_calendarevents'     => 'calendarevents',

                        'backup_import_permissions'        => 'permissions',

                        'backup_import_questionbank'       => 'questionbank',

                        'backup_import_groups'             => 'groups',

                        'backup_import_competencies'       => 'competencies',

                        'backup_import_contentbankcontent' => 'contentbankcontent',

                        'backup_import_legacyfiles'        => 'legacyfiles'

                );

                self::apply_admin_config_defaults($controller, $settings, true);

                if ((!$controller->get_interactive()) &&

                        $controller->get_type() == backup::TYPE_1ACTIVITY) {

                    // This is duplicate - there is no concept of defaults - these settings must be on.

                    $settings = array(

                         'activities',

                         'blocks',

                         'filters',

                         'questionbank'

                    );

                    self::force_enable_settings($controller, $settings);

                }

                break;

            case backup::MODE_AUTOMATED:

                // Load the automated defaults.

                $settings = array(

                        'backup_auto_users'              => 'users',

                        'backup_auto_role_assignments'   => 'role_assignments',

                        'backup_auto_activities'         => 'activities',

                        'backup_auto_blocks'             => 'blocks',

                        'backup_auto_filters'            => 'filters',

                        'backup_auto_comments'           => 'comments',

                        'backup_auto_badges'             => 'badges',

                        'backup_auto_calendarevents'     => 'calendarevents',

                        'backup_auto_userscompletion'    => 'userscompletion',

                        'backup_auto_logs'               => 'logs',

                        'backup_auto_histories'          => 'grade_histories',

                        'backup_auto_questionbank'       => 'questionbank',

                        'backup_auto_groups'             => 'groups',

                        'backup_auto_competencies'       => 'competencies',

                        'backup_auto_contentbankcontent' => 'contentbankcontent',

                        'backup_auto_xapistate'          => 'xapistate',

                        'backup_auto_legacyfiles'        => 'legacyfiles'

                );

                self::apply_admin_config_defaults($controller, $settings, false);

                break;

            default:

                // Nothing to do for other modes (HUB...). Some day we

                // can define defaults (admin UI...) for them if we want to

        }

    }

    /**

     * Turn these settings on. No defaults from admin settings.

     *

     * @param backup_controller $controller

     * @param array $settings a map from admin config names to setting names (Config name => Setting name)

     */

    private static function force_enable_settings(backup_controller $controller, array $settings) {

        $plan = $controller->get_plan();

        foreach ($settings as $config => $settingname) {

            $value = true;

            if ($plan->setting_exists($settingname)) {

                $setting = $plan->get_setting($settingname);

                // We do not allow this setting to be locked for a duplicate function.

                if ($setting->get_status() !== base_setting::NOT_LOCKED) {

                    $setting->set_status(base_setting::NOT_LOCKED);

                }

                $setting->set_value($value);

                $setting->set_status(base_setting::LOCKED_BY_CONFIG);

            } else {

                $controller->log('Unknown setting: ' . $setting, BACKUP::LOG_DEBUG);

            }

        }

    }

    /**

     * Sets the controller settings default values from the admin config.

     *

     * @param backup_controller $controller

     * @param array $settings a map from admin config names to setting names (Config name => Setting name)

     * @param boolean $uselocks whether "locked" admin settings should be honoured

     */

    private static function apply_admin_config_defaults(backup_controller $controller, array $settings, $uselocks) {

        $plan = $controller->get_plan();

        foreach ($settings as $config=>$settingname) {

            $value = get_config('backup', $config);

            if ($value === false) {

                // Ignore this because the config has not been set. get_config

                // returns false if a setting doesn't exist, '0' is returned when

                // the configuration is set to false.

                $controller->log('Could not find a value for the config ' . $config, BACKUP::LOG_DEBUG);

                continue;

            }

            $locked = $uselocks && (get_config('backup', $config.'_locked') == true);

            if ($plan->setting_exists($settingname)) {

                $setting = $plan->get_setting($settingname);

                // We can only update the setting if it isn't already locked by config or permission.

                if ($setting->get_status() !== base_setting::LOCKED_BY_CONFIG

                        && $setting->get_status() !== base_setting::LOCKED_BY_PERMISSION) {

                    $setting->set_value($value);

                    if ($locked) {

                        $setting->set_status(base_setting::LOCKED_BY_CONFIG);

                    }

                }

            } else {

                $controller->log('Unknown setting: ' . $setting, BACKUP::LOG_DEBUG);

            }

        }

    }

    /**

     * Get the progress details of a backup operation.

     * Get backup records directly from database, if the backup has successfully completed

     * there will be no controller object to load.

     *

     * @param string $backupid The backup id to query.

     * @return array $progress The backup progress details.

     */

    public static function get_progress($backupid) {

        global $DB;

        $progress = array();

        $backuprecord = $DB->get_record(

            'backup_controllers',

            array('backupid' => $backupid),

            'status, progress, operation',

            MUST_EXIST);

        $status = $backuprecord->status;

        $progress = $backuprecord->progress;

        $operation = $backuprecord->operation;

        $progress = array('status' => $status, 'progress' => $progress, 'backupid' => $backupid, 'operation' => $operation);

        return $progress;

    }

}