[Summary view] [Print] [Text view]

   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 tempdir/backup 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      protected $plan;   // Restore execution plan
  54  
  55      protected $execution;     // inmediate/delayed
  56      protected $executiontime; // epoch time when we want the restore to be executed (requires cron to run)
  57  
  58      protected $checksum; // Cache @checksumable results for lighter @is_checksum_correct() uses
  59  
  60      /** @var int Number of restore_controllers that are currently executing */
  61      protected static $executing = 0;
  62  
  63      /**
  64       * Constructor.
  65       *
  66       * If you specify a progress monitor, this will be used to report progress
  67       * while loading the plan, as well as for future use. (You can change it
  68       * for a different one later using set_progress.)
  69       *
  70       * @param string $tempdir Directory under tempdir/backup awaiting restore
  71       * @param int $courseid Course id where restore is going to happen
  72       * @param bool $interactive backup::INTERACTIVE_YES[true] or backup::INTERACTIVE_NO[false]
  73       * @param int $mode backup::MODE_[ GENERAL | HUB | IMPORT | SAMESITE ]
  74       * @param int $userid
  75       * @param int $target backup::TARGET_[ NEW_COURSE | CURRENT_ADDING | CURRENT_DELETING | EXISTING_ADDING | EXISTING_DELETING ]
  76       * @param \core\progress\base $progress Optional progress monitor
  77       */
  78      public function __construct($tempdir, $courseid, $interactive, $mode, $userid, $target,
  79              \core\progress\base $progress = null) {
  80          $this->tempdir = $tempdir;
  81          $this->courseid = $courseid;
  82          $this->interactive = $interactive;
  83          $this->mode = $mode;
  84          $this->userid = $userid;
  85          $this->target = $target;
  86  
  87          // Apply some defaults
  88          $this->type = '';
  89          $this->format = backup::FORMAT_UNKNOWN;
  90          $this->execution = backup::EXECUTION_INMEDIATE;
  91          $this->operation = backup::OPERATION_RESTORE;
  92          $this->executiontime = 0;
  93          $this->samesite = false;
  94          $this->checksum = '';
  95          $this->precheck = null;
  96  
  97          // Apply current backup version and release if necessary
  98          backup_controller_dbops::apply_version_and_release();
  99  
 100          // Check courseid is correct
 101          restore_check::check_courseid($this->courseid);
 102  
 103          // Check user is correct
 104          restore_check::check_user($this->userid);
 105  
 106          // Calculate unique $restoreid
 107          $this->calculate_restoreid();
 108  
 109          // Default logger chain (based on interactive/execution)
 110          $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->restoreid);
 111  
 112          // By default there is no progress reporter unless you specify one so it
 113          // can be used during loading of the plan.
 114          if ($progress) {
 115              $this->progress = $progress;
 116          } else {
 117              $this->progress = new \core\progress\none();
 118          }
 119          $this->progress->start_progress('Constructing restore_controller');
 120  
 121          // Instantiate the output_controller singleton and active it if interactive and inmediate
 122          $oc = output_controller::get_instance();
 123          if ($this->interactive == backup::INTERACTIVE_YES && $this->execution == backup::EXECUTION_INMEDIATE) {
 124              $oc->set_active(true);
 125          }
 126  
 127          $this->log('instantiating restore controller', backup::LOG_INFO, $this->restoreid);
 128  
 129          // Set initial status
 130          $this->set_status(backup::STATUS_CREATED);
 131  
 132          // Calculate original restore format
 133          $this->format = backup_general_helper::detect_backup_format($tempdir);
 134  
 135          // If format is not moodle2, set to conversion needed
 136          if ($this->format !== backup::FORMAT_MOODLE) {
 137              $this->set_status(backup::STATUS_REQUIRE_CONV);
 138  
 139          // Else, format is moodle2, load plan, apply security and set status based on interactivity
 140          } else {
 141              // Load plan
 142              $this->load_plan();
 143  
 144              // Perform all initial security checks and apply (2nd param) them to settings automatically
 145              restore_check::check_security($this, true);
 146  
 147              if ($this->interactive == backup::INTERACTIVE_YES) {
 148                  $this->set_status(backup::STATUS_SETTING_UI);
 149              } else {
 150                  $this->set_status(backup::STATUS_NEED_PRECHECK);
 151              }
 152          }
 153  
 154          // Tell progress monitor that we finished loading.
 155          $this->progress->end_progress();
 156      }
 157  
 158      /**
 159       * Clean structures used by the restore_controller
 160       *
 161       * This method clean various structures used by the restore_controller,
 162       * destroying them in an ordered way, so their memory will be gc properly
 163       * by PHP (mainly circular references).
 164       *
 165       * Note that, while it's not mandatory to execute this method, it's highly
 166       * recommended to do so, specially in scripts performing multiple operations
 167       * (like the automated backups) or the system will run out of memory after
 168       * a few dozens of backups)
 169       */
 170      public function destroy() {
 171          // Only need to destroy circulars under the plan. Delegate to it.
 172          $this->plan->destroy();
 173          // Loggers may have also chained references, destroy them. Also closing resources when needed.
 174          $this->logger->destroy();
 175      }
 176  
 177      public function finish_ui() {
 178          if ($this->status != backup::STATUS_SETTING_UI) {
 179              throw new restore_controller_exception('cannot_finish_ui_if_not_setting_ui');
 180          }
 181          $this->set_status(backup::STATUS_NEED_PRECHECK);
 182      }
 183  
 184      public function process_ui_event() {
 185  
 186          // Perform security checks throwing exceptions (2nd param) if something is wrong
 187          restore_check::check_security($this, false);
 188      }
 189  
 190      public function set_status($status) {
 191          // Note: never save_controller() with the object info after STATUS_EXECUTING or the whole controller,
 192          // containing all the steps will be sent to DB. 100% (monster) useless.
 193          $this->log('setting controller status to', backup::LOG_DEBUG, $status);
 194          // TODO: Check it's a correct status.
 195          $this->status = $status;
 196          // Ensure that, once set to backup::STATUS_AWAITING | STATUS_NEED_PRECHECK, controller is stored in DB.
 197          if ($status == backup::STATUS_AWAITING || $status == backup::STATUS_NEED_PRECHECK) {
 198              $this->save_controller();
 199              $tbc = self::load_controller($this->restoreid);
 200              $this->logger = $tbc->logger; // wakeup loggers
 201              $tbc->plan->destroy(); // Clean plan controller structures, keeping logger alive.
 202  
 203          } else if ($status == backup::STATUS_FINISHED_OK) {
 204              // If the operation has ended without error (backup::STATUS_FINISHED_OK)
 205              // proceed by cleaning the object from database. MDL-29262.
 206              $this->save_controller(false, true);
 207          }
 208      }
 209  
 210      public function set_execution($execution, $executiontime = 0) {
 211          $this->log('setting controller execution', backup::LOG_DEBUG);
 212          // TODO: Check valid execution mode
 213          // TODO: Check time in future
 214          // TODO: Check time = 0 if inmediate
 215          $this->execution = $execution;
 216          $this->executiontime = $executiontime;
 217  
 218          // Default logger chain (based on interactive/execution)
 219          $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->restoreid);
 220      }
 221  
 222  // checksumable interface methods
 223  
 224      public function calculate_checksum() {
 225          // Reset current checksum to take it out from calculations!
 226          $this->checksum = '';
 227          // Init checksum
 228          $tempchecksum = md5('tempdir-'    . $this->tempdir .
 229                              'restoreid-'  . $this->restoreid .
 230                              'courseid-'   . $this->courseid .
 231                              'type-'       . $this->type .
 232                              'format-'     . $this->format .
 233                              'interactive-'. $this->interactive .
 234                              'mode-'       . $this->mode .
 235                              'userid-'     . $this->userid .
 236                              'target-'     . $this->target .
 237                              'samesite-'   . $this->samesite .
 238                              'operation-'  . $this->operation .
 239                              'status-'     . $this->status .
 240                              'precheck-'   . backup_general_helper::array_checksum_recursive(array($this->precheck)) .
 241                              'execution-'  . $this->execution .
 242                              'plan-'       . backup_general_helper::array_checksum_recursive(array($this->plan)) .
 243                              'info-'       . backup_general_helper::array_checksum_recursive(array($this->info)) .
 244                              'logger-'     . backup_general_helper::array_checksum_recursive(array($this->logger)));
 245          $this->log('calculating controller checksum', backup::LOG_DEBUG, $tempchecksum);
 246          return $tempchecksum;
 247      }
 248  
 249      public function is_checksum_correct($checksum) {
 250          return $this->checksum === $checksum;
 251      }
 252  
 253      public function get_tempdir() {
 254          return $this->tempdir;
 255      }
 256  
 257      public function get_restoreid() {
 258          return $this->restoreid;
 259      }
 260  
 261      public function get_type() {
 262          return $this->type;
 263      }
 264  
 265      public function get_operation() {
 266          return $this->operation;
 267      }
 268  
 269      public function get_courseid() {
 270          return $this->courseid;
 271      }
 272  
 273      public function get_format() {
 274          return $this->format;
 275      }
 276  
 277      public function get_interactive() {
 278          return $this->interactive;
 279      }
 280  
 281      public function get_mode() {
 282          return $this->mode;
 283      }
 284  
 285      public function get_userid() {
 286          return $this->userid;
 287      }
 288  
 289      public function get_target() {
 290          return $this->target;
 291      }
 292  
 293      public function is_samesite() {
 294          return $this->samesite;
 295      }
 296  
 297      public function get_status() {
 298          return $this->status;
 299      }
 300  
 301      public function get_execution() {
 302          return $this->execution;
 303      }
 304  
 305      public function get_executiontime() {
 306          return $this->executiontime;
 307      }
 308  
 309      /**
 310       * Returns the restore plan
 311       * @return restore_plan
 312       */
 313      public function get_plan() {
 314          return $this->plan;
 315      }
 316  
 317      public function get_info() {
 318          return $this->info;
 319      }
 320  
 321      public function execute_plan() {
 322          // Basic/initial prevention against time/memory limits
 323          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 324          raise_memory_limit(MEMORY_EXTRA);
 325          // If this is not a course restore, inform the plan we are not
 326          // including all the activities for sure. This will affect any
 327          // task/step executed conditionally to stop processing information
 328          // for section and activity restore. MDL-28180.
 329          if ($this->get_type() !== backup::TYPE_1COURSE) {
 330              $this->log('notifying plan about excluded activities by type', backup::LOG_DEBUG);
 331              $this->plan->set_excluding_activities();
 332          }
 333          self::$executing++;
 334          try {
 335              $this->plan->execute();
 336          } catch (Exception $e) {
 337              self::$executing--;
 338              throw $e;
 339          }
 340          self::$executing--;
 341      }
 342  
 343      /**
 344       * Checks whether restore is currently executing. Certain parts of code that
 345       * is called during restore, but not directly part of the restore system, may
 346       * need to behave differently during restore (e.g. do not bother resetting a
 347       * cache because we know it will be reset at end of operation).
 348       *
 349       * @return bool True if any restore is currently executing
 350       */
 351      public static function is_executing() {
 352          return self::$executing > 0;
 353      }
 354  
 355      /**
 356       * Execute the restore prechecks to detect any problem before proceed with restore
 357       *
 358       * This function checks various parts of the restore (versions, users, roles...)
 359       * returning true if everything was ok or false if any warning/error was detected.
 360       * Any warning/error is returned by the get_precheck_results() method.
 361       * Note: if any problem is found it will, automatically, drop all the restore temp
 362       * tables as far as the next step is to inform about the warning/errors. If no problem
 363       * is found, then default behaviour is to keep the temp tables so, in the same request
 364       * restore will be executed, saving a lot of checks to be executed again.
 365       * Note: If for any reason (UI to show after prechecks...) you want to force temp tables
 366       * to be dropped always, you can pass true to the $droptemptablesafter parameter
 367       */
 368      public function execute_precheck($droptemptablesafter = false) {
 369          if (is_array($this->precheck)) {
 370              throw new restore_controller_exception('precheck_alredy_executed', $this->status);
 371          }
 372          if ($this->status != backup::STATUS_NEED_PRECHECK) {
 373              throw new restore_controller_exception('cannot_precheck_wrong_status', $this->status);
 374          }
 375          // Basic/initial prevention against time/memory limits
 376          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 377          raise_memory_limit(MEMORY_EXTRA);
 378          $this->precheck = restore_prechecks_helper::execute_prechecks($this, $droptemptablesafter);
 379          if (!array_key_exists('errors', $this->precheck)) { // No errors, can be executed
 380              $this->set_status(backup::STATUS_AWAITING);
 381          }
 382          if (empty($this->precheck)) { // No errors nor warnings, return true
 383              return true;
 384          }
 385          return false;
 386      }
 387  
 388      public function get_results() {
 389          return $this->plan->get_results();
 390      }
 391  
 392      /**
 393       * Returns true if the prechecks have been executed
 394       * @return bool
 395       */
 396      public function precheck_executed() {
 397          return (is_array($this->precheck));
 398      }
 399  
 400      public function get_precheck_results() {
 401          if (!is_array($this->precheck)) {
 402              throw new restore_controller_exception('precheck_not_executed');
 403          }
 404          return $this->precheck;
 405      }
 406  
 407      /**
 408       * Save controller information
 409       *
 410       * @param bool $includeobj to decide if the object itself must be updated (true) or no (false)
 411       * @param bool $cleanobj to decide if the object itself must be cleaned (true) or no (false)
 412       */
 413      public function save_controller($includeobj = true, $cleanobj = false) {
 414          // Going to save controller to persistent storage, calculate checksum for later checks and save it
 415          // TODO: flag the controller as NA. Any operation on it should be forbidden util loaded back
 416          $this->log('saving controller to db', backup::LOG_DEBUG);
 417          if ($includeobj ) {  // Only calculate checksum if we are going to include the object.
 418              $this->checksum = $this->calculate_checksum();
 419          }
 420          restore_controller_dbops::save_controller($this, $this->checksum, $includeobj, $cleanobj);
 421      }
 422  
 423      public static function load_controller($restoreid) {
 424          // Load controller from persistent storage
 425          // TODO: flag the controller as available. Operations on it can continue
 426          $controller = restore_controller_dbops::load_controller($restoreid);
 427          $controller->log('loading controller from db', backup::LOG_DEBUG);
 428          return $controller;
 429      }
 430  
 431      /**
 432       * class method to provide pseudo random unique "correct" tempdir names
 433       */
 434      public static function get_tempdir_name($courseid = 0, $userid = 0) {
 435          // Current epoch time + courseid + userid + random bits
 436          return md5(time() . '-' . $courseid . '-'. $userid . '-'. random_string(20));
 437      }
 438  
 439      /**
 440       * Converts from current format to backup::MOODLE format
 441       */
 442      public function convert() {
 443          global $CFG;
 444          require_once($CFG->dirroot . '/backup/util/helper/convert_helper.class.php');
 445  
 446          // Basic/initial prevention against time/memory limits
 447          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 448          raise_memory_limit(MEMORY_EXTRA);
 449          $this->progress->start_progress('Backup format conversion');
 450  
 451          if ($this->status != backup::STATUS_REQUIRE_CONV) {
 452              throw new restore_controller_exception('cannot_convert_not_required_status');
 453          }
 454  
 455          $this->log('backup format conversion required', backup::LOG_INFO);
 456  
 457          // Run conversion to the proper format
 458          if (!convert_helper::to_moodle2_format($this->get_tempdir(), $this->format, $this->get_logger())) {
 459              // todo - unable to find the conversion path, what to do now?
 460              // throwing the exception as a temporary solution
 461              throw new restore_controller_exception('unable_to_find_conversion_path');
 462          }
 463  
 464          $this->log('backup format conversion successful', backup::LOG_INFO);
 465  
 466          // If no exceptions were thrown, then we are in the proper format
 467          $this->format = backup::FORMAT_MOODLE;
 468  
 469          // Load plan, apply security and set status based on interactivity
 470          $this->load_plan();
 471  
 472          // Perform all initial security checks and apply (2nd param) them to settings automatically
 473          restore_check::check_security($this, true);
 474  
 475          if ($this->interactive == backup::INTERACTIVE_YES) {
 476              $this->set_status(backup::STATUS_SETTING_UI);
 477          } else {
 478              $this->set_status(backup::STATUS_NEED_PRECHECK);
 479          }
 480          $this->progress->end_progress();
 481      }
 482  
 483  // Protected API starts here
 484  
 485      protected function calculate_restoreid() {
 486          // Current epoch time + tempdir + courseid + interactive + mode + userid + target + operation + random bits
 487          $this->restoreid = md5(time() . '-' . $this->tempdir . '-' . $this->courseid . '-'. $this->interactive . '-' .
 488                                 $this->mode . '-' . $this->userid . '-'. $this->target . '-' . $this->operation . '-' .
 489                                 random_string(20));
 490      }
 491  
 492      protected function load_plan() {
 493          // First of all, we need to introspect the moodle_backup.xml file
 494          // in order to detect all the required stuff. So, create the
 495          // monster $info structure where everything will be defined
 496          $this->log('loading backup info', backup::LOG_DEBUG);
 497          $this->info = backup_general_helper::get_backup_information($this->tempdir);
 498  
 499          // Set the controller type to the one found in the information
 500          $this->type = $this->info->type;
 501  
 502          // Set the controller samesite flag as needed
 503          $this->samesite = backup_general_helper::backup_is_samesite($this->info);
 504  
 505          // Now we load the plan that will be configured following the
 506          // information provided by the $info
 507          $this->log('loading controller plan', backup::LOG_DEBUG);
 508          $this->plan = new restore_plan($this);
 509          $this->plan->build(); // Build plan for this controller
 510          $this->set_status(backup::STATUS_PLANNED);
 511      }
 512  }
 513  
 514  /*
 515   * Exception class used by all the @restore_controller stuff
 516   */
 517  class restore_controller_exception extends backup_exception {
 518  
 519      public function __construct($errorcode, $a=NULL, $debuginfo=null) {
 520          parent::__construct($errorcode, $a, $debuginfo);
 521      }
 522  }