Search moodle.org's
Developer Documentation

See Release Notes

  • Bug fixes for general core bugs in 4.0.x will end 8 May 2023 (12 months).
  • Bug fixes for security issues in 4.0.x will end 13 November 2023 (18 months).
  • PHP version: minimum PHP 7.3.0 Note: the minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is also supported.

Differences Between: [Versions 310 and 400] [Versions 39 and 400] [Versions 400 and 402] [Versions 400 and 403]

   1  <?php
   2  
   3  // This file is part of Moodle - http://moodle.org/
   4  //
   5  // Moodle is free software: you can redistribute it and/or modify
   6  // it under the terms of the GNU General Public License as published by
   7  // the Free Software Foundation, either version 3 of the License, or
   8  // (at your option) any later version.
   9  //
  10  // Moodle is distributed in the hope that it will be useful,
  11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  // GNU General Public License for more details.
  14  //
  15  // You should have received a copy of the GNU General Public License
  16  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17  
  18  /**
  19   * @package moodlecore
  20   * @subpackage backup-controller
  21   * @copyright 2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  22   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  /**
  26   * Class implementing the controller of any restore process
  27   *
  28   * This final class is in charge of controlling all the restore architecture, for any
  29   * type of backup.
  30   *
  31   * TODO: Finish phpdocs
  32   */
  33  class restore_controller extends base_controller {
  34  
  35      protected $tempdir;   // Directory under $CFG->backuptempdir awaiting restore
  36      protected $restoreid; // Unique identificator for this restore
  37  
  38      protected $courseid; // courseid where restore is going to happen
  39  
  40      protected $type;   // Type of backup (activity, section, course)
  41      protected $format; // Format of backup (moodle, imscc)
  42      protected $interactive; // yes/no
  43      protected $mode;   // Purpose of the backup (default settings)
  44      protected $userid; // user id executing the restore
  45      protected $operation; // Type of operation (backup/restore)
  46      protected $target;    // Restoring to new/existing/current_adding/_deleting
  47      protected $samesite;  // Are we restoring to the same site where the backup was generated
  48  
  49      protected $status; // Current status of the controller (created, planned, configured...)
  50      protected $precheck;    // Results of the execution of restore prechecks
  51  
  52      protected $info;   // Information retrieved from backup contents
  53      /** @var restore_plan */
  54      protected $plan;   // Restore execution plan
  55  
  56      /**
  57       * Immediate/delayed execution type.
  58       * @var integer
  59       */
  60      protected $execution;
  61      protected $executiontime; // epoch time when we want the restore to be executed (requires cron to run)
  62  
  63      protected $checksum; // Cache @checksumable results for lighter @is_checksum_correct() uses
  64  
  65      /** @var int Number of restore_controllers that are currently executing */
  66      protected static $executing = 0;
  67  
  68      /**
  69       * Holds the relevant destination information for course copy operations.
  70       *
  71       * @var \stdClass.
  72       */
  73      protected $copy;
  74  
  75      /**
  76       * Constructor.
  77       *
  78       * If you specify a progress monitor, this will be used to report progress
  79       * while loading the plan, as well as for future use. (You can change it
  80       * for a different one later using set_progress.)
  81       *
  82       * @param string $tempdir Directory under $CFG->backuptempdir awaiting restore
  83       * @param int $courseid Course id where restore is going to happen
  84       * @param bool $interactive backup::INTERACTIVE_YES[true] or backup::INTERACTIVE_NO[false]
  85       * @param int $mode backup::MODE_[ GENERAL | HUB | IMPORT | SAMESITE ]
  86       * @param int $userid
  87       * @param int $target backup::TARGET_[ NEW_COURSE | CURRENT_ADDING | CURRENT_DELETING | EXISTING_ADDING | EXISTING_DELETING ]
  88       * @param \core\progress\base $progress Optional progress monitor
  89       * @param \stdClass $copydata Course copy data, required when in MODE_COPY
  90       * @param bool $releasesession Should release the session? backup::RELEASESESSION_YES or backup::RELEASESESSION_NO
  91       */
  92      public function __construct($tempdir, $courseid, $interactive, $mode, $userid, $target,
  93              \core\progress\base $progress = null, $releasesession = backup::RELEASESESSION_NO, ?\stdClass $copydata = null) {
  94  
  95          if ($mode == backup::MODE_COPY && is_null($copydata)) {
  96              throw new restore_controller_exception('cannot_instantiate_missing_copydata');
  97          }
  98  
  99          $this->copy = $copydata;
 100          $this->tempdir = $tempdir;
 101          $this->courseid = $courseid;
 102          $this->interactive = $interactive;
 103          $this->mode = $mode;
 104          $this->userid = $userid;
 105          $this->target = $target;
 106          $this->releasesession = $releasesession;
 107  
 108          // Apply some defaults
 109          $this->type = '';
 110          $this->format = backup::FORMAT_UNKNOWN;
 111          $this->operation = backup::OPERATION_RESTORE;
 112          $this->executiontime = 0;
 113          $this->samesite = false;
 114          $this->checksum = '';
 115          $this->precheck = null;
 116  
 117          // Apply current backup version and release if necessary
 118          backup_controller_dbops::apply_version_and_release();
 119  
 120          // Check courseid is correct
 121          restore_check::check_courseid($this->courseid);
 122  
 123          // Check user is correct
 124          restore_check::check_user($this->userid);
 125  
 126          // Calculate unique $restoreid
 127          $this->calculate_restoreid();
 128  
 129          // Default logger chain (based on interactive/execution)
 130          $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->restoreid);
 131  
 132          // Set execution based on backup mode.
 133          if ($mode == backup::MODE_ASYNC || $mode == backup::MODE_COPY) {
 134              $this->execution = backup::EXECUTION_DELAYED;
 135          } else {
 136              $this->execution = backup::EXECUTION_INMEDIATE;
 137          }
 138  
 139          // By default there is no progress reporter unless you specify one so it
 140          // can be used during loading of the plan.
 141          if ($progress) {
 142              $this->progress = $progress;
 143          } else {
 144              $this->progress = new \core\progress\none();
 145          }
 146          $this->progress->start_progress('Constructing restore_controller');
 147  
 148          // Instantiate the output_controller singleton and active it if interactive and immediate.
 149          $oc = output_controller::get_instance();
 150          if ($this->interactive == backup::INTERACTIVE_YES && $this->execution == backup::EXECUTION_INMEDIATE) {
 151              $oc->set_active(true);
 152          }
 153  
 154          $this->log('instantiating restore controller', backup::LOG_INFO, $this->restoreid);
 155  
 156          // Set initial status
 157          $this->set_status(backup::STATUS_CREATED);
 158  
 159          // Calculate original restore format
 160          $this->format = backup_general_helper::detect_backup_format($tempdir);
 161  
 162          // If format is not moodle2, set to conversion needed
 163          if ($this->format !== backup::FORMAT_MOODLE) {
 164              $this->set_status(backup::STATUS_REQUIRE_CONV);
 165  
 166          // Else, format is moodle2, load plan, apply security and set status based on interactivity
 167          } else {
 168              // Load plan
 169              $this->load_plan();
 170  
 171              // Apply all default settings (based on type/format/mode).
 172              $this->apply_defaults();
 173  
 174              // Perform all initial security checks and apply (2nd param) them to settings automatically
 175              restore_check::check_security($this, true);
 176  
 177              if ($this->interactive == backup::INTERACTIVE_YES) {
 178                  $this->set_status(backup::STATUS_SETTING_UI);
 179              } else {
 180                  $this->set_status(backup::STATUS_NEED_PRECHECK);
 181              }
 182          }
 183  
 184          // Tell progress monitor that we finished loading.
 185          $this->progress->end_progress();
 186      }
 187  
 188      /**
 189       * Clean structures used by the restore_controller
 190       *
 191       * This method clean various structures used by the restore_controller,
 192       * destroying them in an ordered way, so their memory will be gc properly
 193       * by PHP (mainly circular references).
 194       *
 195       * Note that, while it's not mandatory to execute this method, it's highly
 196       * recommended to do so, specially in scripts performing multiple operations
 197       * (like the automated backups) or the system will run out of memory after
 198       * a few dozens of backups)
 199       */
 200      public function destroy() {
 201          // Only need to destroy circulars under the plan. Delegate to it.
 202          $this->plan->destroy();
 203          // Loggers may have also chained references, destroy them. Also closing resources when needed.
 204          $this->logger->destroy();
 205      }
 206  
 207      public function finish_ui() {
 208          if ($this->status != backup::STATUS_SETTING_UI) {
 209              throw new restore_controller_exception('cannot_finish_ui_if_not_setting_ui');
 210          }
 211          $this->set_status(backup::STATUS_NEED_PRECHECK);
 212      }
 213  
 214      public function process_ui_event() {
 215  
 216          // Perform security checks throwing exceptions (2nd param) if something is wrong
 217          restore_check::check_security($this, false);
 218      }
 219  
 220      public function set_status($status) {
 221          // Note: never save_controller() with the object info after STATUS_EXECUTING or the whole controller,
 222          // containing all the steps will be sent to DB. 100% (monster) useless.
 223          $this->log('setting controller status to', backup::LOG_DEBUG, $status);
 224          // TODO: Check it's a correct status.
 225          $this->status = $status;
 226          // Ensure that, once set to backup::STATUS_AWAITING | STATUS_NEED_PRECHECK, controller is stored in DB.
 227          // Also save if executing so we can better track progress.
 228          if ($status == backup::STATUS_AWAITING || $status == backup::STATUS_NEED_PRECHECK || $status == backup::STATUS_EXECUTING) {
 229              $this->save_controller();
 230              $tbc = self::load_controller($this->restoreid);
 231              $this->logger = $tbc->logger; // wakeup loggers
 232              $tbc->plan->destroy(); // Clean plan controller structures, keeping logger alive.
 233  
 234          } else if ($status == backup::STATUS_FINISHED_OK) {
 235              // If the operation has ended without error (backup::STATUS_FINISHED_OK)
 236              // proceed by cleaning the object from database. MDL-29262.
 237              $this->save_controller(false, true);
 238          } else if ($status == backup::STATUS_FINISHED_ERR) {
 239              // If the operation has ended with an error save the controller
 240              // preserving the object in the database. We may want it for debugging.
 241              $this->save_controller();
 242          }
 243      }
 244  
 245      public function set_execution($execution, $executiontime = 0) {
 246          $this->log('setting controller execution', backup::LOG_DEBUG);
 247          // TODO: Check valid execution mode.
 248          // TODO: Check time in future.
 249          // TODO: Check time = 0 if immediate.
 250          $this->execution = $execution;
 251          $this->executiontime = $executiontime;
 252  
 253          // Default logger chain (based on interactive/execution)
 254          $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->restoreid);
 255      }
 256  
 257  // checksumable interface methods
 258  
 259      public function calculate_checksum() {
 260          // Reset current checksum to take it out from calculations!
 261          $this->checksum = '';
 262          // Init checksum
 263          $tempchecksum = md5('tempdir-'    . $this->tempdir .
 264                              'restoreid-'  . $this->restoreid .
 265                              'courseid-'   . $this->courseid .
 266                              'type-'       . $this->type .
 267                              'format-'     . $this->format .
 268                              'interactive-'. $this->interactive .
 269                              'mode-'       . $this->mode .
 270                              'userid-'     . $this->userid .
 271                              'target-'     . $this->target .
 272                              'samesite-'   . $this->samesite .
 273                              'operation-'  . $this->operation .
 274                              'status-'     . $this->status .
 275                              'precheck-'   . backup_general_helper::array_checksum_recursive(array($this->precheck)) .
 276                              'execution-'  . $this->execution .
 277                              'plan-'       . backup_general_helper::array_checksum_recursive(array($this->plan)) .
 278                              'info-'       . backup_general_helper::array_checksum_recursive(array($this->info)) .
 279                              'logger-'     . backup_general_helper::array_checksum_recursive(array($this->logger)));
 280          $this->log('calculating controller checksum', backup::LOG_DEBUG, $tempchecksum);
 281          return $tempchecksum;
 282      }
 283  
 284      public function is_checksum_correct($checksum) {
 285          return $this->checksum === $checksum;
 286      }
 287  
 288      public function get_tempdir() {
 289          return $this->tempdir;
 290      }
 291  
 292      public function get_restoreid() {
 293          return $this->restoreid;
 294      }
 295  
 296      public function get_type() {
 297          return $this->type;
 298      }
 299  
 300      public function get_operation() {
 301          return $this->operation;
 302      }
 303  
 304      public function get_courseid() {
 305          return $this->courseid;
 306      }
 307  
 308      public function get_format() {
 309          return $this->format;
 310      }
 311  
 312      public function get_interactive() {
 313          return $this->interactive;
 314      }
 315  
 316      public function get_mode() {
 317          return $this->mode;
 318      }
 319  
 320      public function get_userid() {
 321          return $this->userid;
 322      }
 323  
 324      public function get_target() {
 325          return $this->target;
 326      }
 327  
 328      public function is_samesite() {
 329          return $this->samesite;
 330      }
 331  
 332      public function get_status() {
 333          return $this->status;
 334      }
 335  
 336      public function get_execution() {
 337          return $this->execution;
 338      }
 339  
 340      public function get_executiontime() {
 341          return $this->executiontime;
 342      }
 343  
 344      /**
 345       * Returns the restore plan
 346       * @return restore_plan
 347       */
 348      public function get_plan() {
 349          return $this->plan;
 350      }
 351      /**
 352       * Gets the value for the requested setting
 353       *
 354       * @param string $name
 355       * @param bool $default
 356       * @return mixed
 357       */
 358      public function get_setting_value($name, $default = false) {
 359          try {
 360              return $this->get_plan()->get_setting($name)->get_value();
 361          } catch (Exception $e) {
 362              debugging('Failed to find the setting: '.$name, DEBUG_DEVELOPER);
 363              return $default;
 364          }
 365      }
 366  
 367      /**
 368       * For debug only. Get a simple test display of all the settings.
 369       *
 370       * @return string
 371       */
 372      public function debug_display_all_settings_values(): string {
 373          return $this->get_plan()->debug_display_all_settings_values();
 374      }
 375  
 376      public function get_info() {
 377          return $this->info;
 378      }
 379  
 380      public function execute_plan() {
 381          // Basic/initial prevention against time/memory limits
 382          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 383          raise_memory_limit(MEMORY_EXTRA);
 384  
 385          // Release the session so other tabs in the same session are not blocked.
 386          if ($this->get_releasesession() === backup::RELEASESESSION_YES) {
 387              \core\session\manager::write_close();
 388          }
 389  
 390          // Do course cleanup precheck, if required. This was originally in restore_ui. Moved to handle async backup/restore.
 391          if ($this->get_target() == backup::TARGET_CURRENT_DELETING || $this->get_target() == backup::TARGET_EXISTING_DELETING) {
 392              $options = array();
 393              $options['keep_roles_and_enrolments'] = $this->get_setting_value('keep_roles_and_enrolments');
 394              $options['keep_groups_and_groupings'] = $this->get_setting_value('keep_groups_and_groupings');
 395              $options['userid'] = $this->userid;
 396              restore_dbops::delete_course_content($this->get_courseid(), $options);
 397          }
 398          // If this is not a course restore or single activity restore (e.g. duplicate), inform the plan we are not
 399          // including all the activities for sure. This will affect any
 400          // task/step executed conditionally to stop processing information
 401          // for section and activity restore. MDL-28180.
 402          if ($this->get_type() !== backup::TYPE_1COURSE && $this->get_type() !== backup::TYPE_1ACTIVITY) {
 403              $this->log('notifying plan about excluded activities by type', backup::LOG_DEBUG);
 404              $this->plan->set_excluding_activities();
 405          }
 406          self::$executing++;
 407          try {
 408              $this->plan->execute();
 409          } catch (Exception $e) {
 410              self::$executing--;
 411              throw $e;
 412          }
 413          self::$executing--;
 414      }
 415  
 416      /**
 417       * Checks whether restore is currently executing. Certain parts of code that
 418       * is called during restore, but not directly part of the restore system, may
 419       * need to behave differently during restore (e.g. do not bother resetting a
 420       * cache because we know it will be reset at end of operation).
 421       *
 422       * @return bool True if any restore is currently executing
 423       */
 424      public static function is_executing() {
 425          return self::$executing > 0;
 426      }
 427  
 428      /**
 429       * Execute the restore prechecks to detect any problem before proceed with restore
 430       *
 431       * This function checks various parts of the restore (versions, users, roles...)
 432       * returning true if everything was ok or false if any warning/error was detected.
 433       * Any warning/error is returned by the get_precheck_results() method.
 434       * Note: if any problem is found it will, automatically, drop all the restore temp
 435       * tables as far as the next step is to inform about the warning/errors. If no problem
 436       * is found, then default behaviour is to keep the temp tables so, in the same request
 437       * restore will be executed, saving a lot of checks to be executed again.
 438       * Note: If for any reason (UI to show after prechecks...) you want to force temp tables
 439       * to be dropped always, you can pass true to the $droptemptablesafter parameter
 440       */
 441      public function execute_precheck($droptemptablesafter = false) {
 442          if (is_array($this->precheck)) {
 443              throw new restore_controller_exception('precheck_alredy_executed', $this->status);
 444          }
 445          if ($this->status != backup::STATUS_NEED_PRECHECK) {
 446              throw new restore_controller_exception('cannot_precheck_wrong_status', $this->status);
 447          }
 448          // Basic/initial prevention against time/memory limits
 449          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 450          raise_memory_limit(MEMORY_EXTRA);
 451          $this->precheck = restore_prechecks_helper::execute_prechecks($this, $droptemptablesafter);
 452          if (!array_key_exists('errors', $this->precheck)) { // No errors, can be executed
 453              $this->set_status(backup::STATUS_AWAITING);
 454          }
 455          if (empty($this->precheck)) { // No errors nor warnings, return true
 456              return true;
 457          }
 458          return false;
 459      }
 460  
 461      public function get_results() {
 462          return $this->plan->get_results();
 463      }
 464  
 465      /**
 466       * Returns true if the prechecks have been executed
 467       * @return bool
 468       */
 469      public function precheck_executed() {
 470          return (is_array($this->precheck));
 471      }
 472  
 473      public function get_precheck_results() {
 474          if (!is_array($this->precheck)) {
 475              throw new restore_controller_exception('precheck_not_executed');
 476          }
 477          return $this->precheck;
 478      }
 479  
 480      /**
 481       * Save controller information
 482       *
 483       * @param bool $includeobj to decide if the object itself must be updated (true) or no (false)
 484       * @param bool $cleanobj to decide if the object itself must be cleaned (true) or no (false)
 485       */
 486      public function save_controller($includeobj = true, $cleanobj = false) {
 487          // Going to save controller to persistent storage, calculate checksum for later checks and save it
 488          // TODO: flag the controller as NA. Any operation on it should be forbidden util loaded back
 489          $this->log('saving controller to db', backup::LOG_DEBUG);
 490          if ($includeobj ) {  // Only calculate checksum if we are going to include the object.
 491              $this->checksum = $this->calculate_checksum();
 492          }
 493          restore_controller_dbops::save_controller($this, $this->checksum, $includeobj, $cleanobj);
 494      }
 495  
 496      public static function load_controller($restoreid) {
 497          // Load controller from persistent storage
 498          // TODO: flag the controller as available. Operations on it can continue
 499          $controller = restore_controller_dbops::load_controller($restoreid);
 500          $controller->log('loading controller from db', backup::LOG_DEBUG);
 501          return $controller;
 502      }
 503  
 504      /**
 505       * class method to provide pseudo random unique "correct" tempdir names
 506       */
 507      public static function get_tempdir_name($courseid = 0, $userid = 0) {
 508          // Current epoch time + courseid + userid + random bits
 509          return md5(time() . '-' . $courseid . '-'. $userid . '-'. random_string(20));
 510      }
 511  
 512      /**
 513       * Converts from current format to backup::MOODLE format
 514       */
 515      public function convert() {
 516          global $CFG;
 517          require_once($CFG->dirroot . '/backup/util/helper/convert_helper.class.php');
 518  
 519          // Basic/initial prevention against time/memory limits
 520          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 521          raise_memory_limit(MEMORY_EXTRA);
 522          $this->progress->start_progress('Backup format conversion');
 523  
 524          if ($this->status != backup::STATUS_REQUIRE_CONV) {
 525              throw new restore_controller_exception('cannot_convert_not_required_status');
 526          }
 527  
 528          $this->log('backup format conversion required', backup::LOG_INFO);
 529  
 530          // Run conversion to the proper format
 531          if (!convert_helper::to_moodle2_format($this->get_tempdir(), $this->format, $this->get_logger())) {
 532              // todo - unable to find the conversion path, what to do now?
 533              // throwing the exception as a temporary solution
 534              throw new restore_controller_exception('unable_to_find_conversion_path');
 535          }
 536  
 537          $this->log('backup format conversion successful', backup::LOG_INFO);
 538  
 539          // If no exceptions were thrown, then we are in the proper format
 540          $this->format = backup::FORMAT_MOODLE;
 541  
 542          // Load plan, apply security and set status based on interactivity
 543          $this->load_plan();
 544  
 545          // Perform all initial security checks and apply (2nd param) them to settings automatically
 546          restore_check::check_security($this, true);
 547  
 548          if ($this->interactive == backup::INTERACTIVE_YES) {
 549              $this->set_status(backup::STATUS_SETTING_UI);
 550          } else {
 551              $this->set_status(backup::STATUS_NEED_PRECHECK);
 552          }
 553          $this->progress->end_progress();
 554      }
 555  
 556      /**
 557       * Do the necessary copy preparation actions.
 558       * This method should only be called once the backup of a copy operation is completed.
 559       *
 560       * @throws restore_controller_exception
 561       */
 562      public function prepare_copy(): void {
 563          // Check that we are in the correct mode.
 564          if ($this->mode != backup::MODE_COPY) {
 565              throw new restore_controller_exception('cannot_prepare_copy_wrong_mode');
 566          }
 567  
 568          $this->progress->start_progress('Prepare Copy');
 569  
 570          // If no exceptions were thrown, then we are in the proper format.
 571          $this->format = backup::FORMAT_MOODLE;
 572  
 573          // Load plan, apply security and set status based on interactivity.
 574          $this->load_plan();
 575  
 576          $this->set_status(backup::STATUS_NEED_PRECHECK);
 577          $this->progress->end_progress();
 578      }
 579  
 580      /**
 581       * Get the course copy data.
 582       *
 583       * @return \stdClass
 584       */
 585      public function get_copy(): \stdClass {
 586          if ($this->mode != backup::MODE_COPY) {
 587              throw new restore_controller_exception('cannot_get_copy_wrong_mode');
 588          }
 589  
 590          return $this->copy;
 591      }
 592  
 593  // Protected API starts here
 594  
 595      protected function calculate_restoreid() {
 596          // Current epoch time + tempdir + courseid + interactive + mode + userid + target + operation + random bits
 597          $this->restoreid = md5(time() . '-' . $this->tempdir . '-' . $this->courseid . '-'. $this->interactive . '-' .
 598                                 $this->mode . '-' . $this->userid . '-'. $this->target . '-' . $this->operation . '-' .
 599                                 random_string(20));
 600      }
 601  
 602      protected function load_plan() {
 603          // First of all, we need to introspect the moodle_backup.xml file
 604          // in order to detect all the required stuff. So, create the
 605          // monster $info structure where everything will be defined
 606          $this->log('loading backup info', backup::LOG_DEBUG);
 607          $this->info = backup_general_helper::get_backup_information($this->tempdir);
 608  
 609          // Set the controller type to the one found in the information
 610          $this->type = $this->info->type;
 611  
 612          // Set the controller samesite flag as needed
 613          $this->samesite = backup_general_helper::backup_is_samesite($this->info);
 614  
 615          // Now we load the plan that will be configured following the
 616          // information provided by the $info
 617          $this->log('loading controller plan', backup::LOG_DEBUG);
 618          $this->plan = new restore_plan($this);
 619          $this->plan->build(); // Build plan for this controller
 620          $this->set_status(backup::STATUS_PLANNED);
 621      }
 622  
 623      /**
 624       * Apply defaults from the global admin settings
 625       */
 626      protected function apply_defaults() {
 627          $this->log('applying restore defaults', backup::LOG_DEBUG);
 628          restore_controller_dbops::apply_config_defaults($this);
 629          $this->set_status(backup::STATUS_CONFIGURED);
 630      }
 631  }
 632  
 633  /*
 634   * Exception class used by all the @restore_controller stuff
 635   */
 636  class restore_controller_exception extends backup_exception {
 637  
 638      public function __construct($errorcode, $a=NULL, $debuginfo=null) {
 639          parent::__construct($errorcode, $a, $debuginfo);
 640      }
 641  }