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   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 backup process
  27   *
  28   * This final class is in charge of controlling all the backup architecture, for any
  29   * type of backup. Based in type, format, interactivity and target, it stores the
  30   * whole execution plan and settings that will be used later by the @backup_worker,
  31   * applies all the defaults, performs all the security contraints and is in charge
  32   * of handling the ui if necessary. Also logging strategy is defined here.
  33   *
  34   * Note the class is 100% neutral and usable for *any* backup. It just stores/requests
  35   * all the needed information from other backup classes in order to have everything well
  36   * structured in order to allow the @backup_worker classes to do their job.
  37   *
  38   * In other words, a mammoth class, but don't worry, practically everything is delegated/
  39   * aggregated!)
  40   *
  41   * TODO: Finish phpdocs
  42   */
  43  class backup_controller extends base_controller {
  44  
  45      protected $backupid; // Unique identificator for this backup
  46  
  47      protected $type;   // Type of backup (activity, section, course)
  48      protected $id;     // Course/section/course_module id to backup
  49      protected $courseid; // courseid where the id belongs to
  50      protected $format; // Format of backup (moodle, imscc)
  51      protected $interactive; // yes/no
  52      protected $mode;   // Purpose of the backup (default settings)
  53      protected $userid; // user id executing the backup
  54      protected $operation; // Type of operation (backup/restore)
  55  
  56      protected $status; // Current status of the controller (created, planned, configured...)
  57  
  58      protected $plan;   // Backup execution plan
  59      protected $includefiles; // Whether this backup includes files or not.
  60  
  61      protected $execution;     // inmediate/delayed
  62      protected $executiontime; // epoch time when we want the backup to be executed (requires cron to run)
  63  
  64      protected $destination; // Destination chain object (fs_moodle, fs_os, db, email...)
  65  
  66      protected $checksum; // Cache @checksumable results for lighter @is_checksum_correct() uses
  67  
  68      /**
  69       * Constructor for the backup controller class.
  70       *
  71       * @param int $type Type of the backup; One of backup::TYPE_1COURSE, TYPE_1SECTION, TYPE_1ACTIVITY
  72       * @param int $id The ID of the item to backup; e.g the course id
  73       * @param int $format The backup format to use; Most likely backup::FORMAT_MOODLE
  74       * @param bool $interactive Whether this backup will require user interaction; backup::INTERACTIVE_YES or INTERACTIVE_NO
  75       * @param int $mode One of backup::MODE_GENERAL, MODE_IMPORT, MODE_SAMESITE, MODE_HUB, MODE_AUTOMATED
  76       * @param int $userid The id of the user making the backup
  77       */
  78      public function __construct($type, $id, $format, $interactive, $mode, $userid){
  79          $this->type = $type;
  80          $this->id   = $id;
  81          $this->courseid = backup_controller_dbops::get_courseid_from_type_id($this->type, $this->id);
  82          $this->format = $format;
  83          $this->interactive = $interactive;
  84          $this->mode = $mode;
  85          $this->userid = $userid;
  86  
  87          // Apply some defaults
  88          $this->execution = backup::EXECUTION_INMEDIATE;
  89          $this->operation = backup::OPERATION_BACKUP;
  90          $this->executiontime = 0;
  91          $this->checksum = '';
  92  
  93          // Apply current backup version and release if necessary
  94          backup_controller_dbops::apply_version_and_release();
  95  
  96          // Check format and type are correct
  97          backup_check::check_format_and_type($this->format, $this->type);
  98  
  99          // Check id is correct
 100          backup_check::check_id($this->type, $this->id);
 101  
 102          // Check user is correct
 103          backup_check::check_user($this->userid);
 104  
 105          // Calculate unique $backupid
 106          $this->calculate_backupid();
 107  
 108          // Default logger chain (based on interactive/execution)
 109          $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->backupid);
 110  
 111          // By default there is no progress reporter. Interfaces that wish to
 112          // display progress must set it.
 113          $this->progress = new \core\progress\null();
 114  
 115          // Instantiate the output_controller singleton and active it if interactive and inmediate
 116          $oc = output_controller::get_instance();
 117          if ($this->interactive == backup::INTERACTIVE_YES && $this->execution == backup::EXECUTION_INMEDIATE) {
 118              $oc->set_active(true);
 119          }
 120  
 121          $this->log('instantiating backup controller', backup::LOG_INFO, $this->backupid);
 122  
 123          // Default destination chain (based on type/mode/execution)
 124          $this->destination = backup_factory::get_destination_chain($this->type, $this->id, $this->mode, $this->execution);
 125  
 126          // Set initial status
 127          $this->set_status(backup::STATUS_CREATED);
 128  
 129          // Load plan (based on type/format)
 130          $this->load_plan();
 131  
 132          // Apply all default settings (based on type/format/mode)
 133          $this->apply_defaults();
 134  
 135          // Perform all initial security checks and apply (2nd param) them to settings automatically
 136          backup_check::check_security($this, true);
 137  
 138          // Set status based on interactivity
 139          if ($this->interactive == backup::INTERACTIVE_YES) {
 140              $this->set_status(backup::STATUS_SETTING_UI);
 141          } else {
 142              $this->set_status(backup::STATUS_AWAITING);
 143          }
 144      }
 145  
 146      /**
 147       * Clean structures used by the backup_controller
 148       *
 149       * This method clean various structures used by the backup_controller,
 150       * destroying them in an ordered way, so their memory will be gc properly
 151       * by PHP (mainly circular references).
 152       *
 153       * Note that, while it's not mandatory to execute this method, it's highly
 154       * recommended to do so, specially in scripts performing multiple operations
 155       * (like the automated backups) or the system will run out of memory after
 156       * a few dozens of backups)
 157       */
 158      public function destroy() {
 159          // Only need to destroy circulars under the plan. Delegate to it.
 160          $this->plan->destroy();
 161      }
 162  
 163      public function finish_ui() {
 164          if ($this->status != backup::STATUS_SETTING_UI) {
 165              throw new backup_controller_exception('cannot_finish_ui_if_not_setting_ui');
 166          }
 167          $this->set_status(backup::STATUS_AWAITING);
 168      }
 169  
 170      public function process_ui_event() {
 171  
 172          // Perform security checks throwing exceptions (2nd param) if something is wrong
 173          backup_check::check_security($this, false);
 174      }
 175  
 176      public function set_status($status) {
 177          // Note: never save_controller() with the object info after STATUS_EXECUTING or the whole controller,
 178          // containing all the steps will be sent to DB. 100% (monster) useless.
 179          $this->log('setting controller status to', backup::LOG_DEBUG, $status);
 180          // TODO: Check it's a correct status.
 181          $this->status = $status;
 182          // Ensure that, once set to backup::STATUS_AWAITING, controller is stored in DB.
 183          if ($status == backup::STATUS_AWAITING) {
 184              $this->save_controller();
 185              $tbc = self::load_controller($this->backupid);
 186              $this->logger = $tbc->logger; // wakeup loggers
 187              $tbc->destroy(); // Clean temp controller structures
 188  
 189          } else if ($status == backup::STATUS_FINISHED_OK) {
 190              // If the operation has ended without error (backup::STATUS_FINISHED_OK)
 191              // proceed by cleaning the object from database. MDL-29262.
 192              $this->save_controller(false, true);
 193          }
 194      }
 195  
 196      public function set_execution($execution, $executiontime = 0) {
 197          $this->log('setting controller execution', backup::LOG_DEBUG);
 198          // TODO: Check valid execution mode
 199          // TODO: Check time in future
 200          // TODO: Check time = 0 if inmediate
 201          $this->execution = $execution;
 202          $this->executiontime = $executiontime;
 203  
 204          // Default destination chain (based on type/mode/execution)
 205          $this->destination = backup_factory::get_destination_chain($this->type, $this->id, $this->mode, $this->execution);
 206  
 207          // Default logger chain (based on interactive/execution)
 208          $this->logger = backup_factory::get_logger_chain($this->interactive, $this->execution, $this->backupid);
 209      }
 210  
 211  // checksumable interface methods
 212  
 213      public function calculate_checksum() {
 214          // Reset current checksum to take it out from calculations!
 215          $this->checksum = '';
 216          // Init checksum
 217          $tempchecksum = md5('backupid-'   . $this->backupid .
 218                              'type-'       . $this->type .
 219                              'id-'         . $this->id .
 220                              'format-'     . $this->format .
 221                              'interactive-'. $this->interactive .
 222                              'mode-'       . $this->mode .
 223                              'userid-'     . $this->userid .
 224                              'operation-'  . $this->operation .
 225                              'status-'     . $this->status .
 226                              'execution-'  . $this->execution .
 227                              'plan-'       . backup_general_helper::array_checksum_recursive(array($this->plan)) .
 228                              'destination-'. backup_general_helper::array_checksum_recursive(array($this->destination)) .
 229                              'logger-'     . backup_general_helper::array_checksum_recursive(array($this->logger)));
 230          $this->log('calculating controller checksum', backup::LOG_DEBUG, $tempchecksum);
 231          return $tempchecksum;
 232      }
 233  
 234      public function is_checksum_correct($checksum) {
 235          return $this->checksum === $checksum;
 236      }
 237  
 238      public function get_backupid() {
 239          return $this->backupid;
 240      }
 241  
 242      public function get_type() {
 243          return $this->type;
 244      }
 245  
 246      /**
 247       * Returns the current value of the include_files setting.
 248       * This setting is intended to ensure that files are not included in
 249       * generated backups.
 250       *
 251       * @return int Indicates whether files should be included in backups.
 252       */
 253      public function get_include_files() {
 254          return $this->includefiles;
 255      }
 256  
 257      public function get_operation() {
 258          return $this->operation;
 259      }
 260  
 261      public function get_id() {
 262          return $this->id;
 263      }
 264  
 265      public function get_courseid() {
 266          return $this->courseid;
 267      }
 268  
 269      public function get_format() {
 270          return $this->format;
 271      }
 272  
 273      public function get_interactive() {
 274          return $this->interactive;
 275      }
 276  
 277      public function get_mode() {
 278          return $this->mode;
 279      }
 280  
 281      public function get_userid() {
 282          return $this->userid;
 283      }
 284  
 285      public function get_status() {
 286          return $this->status;
 287      }
 288  
 289      public function get_execution() {
 290          return $this->execution;
 291      }
 292  
 293      public function get_executiontime() {
 294          return $this->executiontime;
 295      }
 296  
 297      /**
 298       * @return backup_plan
 299       */
 300      public function get_plan() {
 301          return $this->plan;
 302      }
 303  
 304      /**
 305       * Executes the backup
 306       * @return void Throws and exception of completes
 307       */
 308      public function execute_plan() {
 309          // Basic/initial prevention against time/memory limits
 310          core_php_time_limit::raise(1 * 60 * 60); // 1 hour for 1 course initially granted
 311          raise_memory_limit(MEMORY_EXTRA);
 312          // If this is not a course backup, inform the plan we are not
 313          // including all the activities for sure. This will affect any
 314          // task/step executed conditionally to stop including information
 315          // for section and activity backup. MDL-28180.
 316          if ($this->get_type() !== backup::TYPE_1COURSE) {
 317              $this->log('notifying plan about excluded activities by type', backup::LOG_DEBUG);
 318              $this->plan->set_excluding_activities();
 319          }
 320          return $this->plan->execute();
 321      }
 322  
 323      public function get_results() {
 324          return $this->plan->get_results();
 325      }
 326  
 327      /**
 328       * Save controller information
 329       *
 330       * @param bool $includeobj to decide if the object itself must be updated (true) or no (false)
 331       * @param bool $cleanobj to decide if the object itself must be cleaned (true) or no (false)
 332       */
 333      public function save_controller($includeobj = true, $cleanobj = false) {
 334          // Going to save controller to persistent storage, calculate checksum for later checks and save it
 335          // TODO: flag the controller as NA. Any operation on it should be forbidden util loaded back
 336          $this->log('saving controller to db', backup::LOG_DEBUG);
 337          if ($includeobj ) {  // Only calculate checksum if we are going to include the object.
 338              $this->checksum = $this->calculate_checksum();
 339          }
 340          backup_controller_dbops::save_controller($this, $this->checksum, $includeobj, $cleanobj);
 341      }
 342  
 343      public static function load_controller($backupid) {
 344          // Load controller from persistent storage
 345          // TODO: flag the controller as available. Operations on it can continue
 346          $controller = backup_controller_dbops::load_controller($backupid);
 347          $controller->log('loading controller from db', backup::LOG_DEBUG);
 348          return $controller;
 349      }
 350  
 351  // Protected API starts here
 352  
 353      protected function calculate_backupid() {
 354          // Current epoch time + type + id + format + interactive + mode + userid + operation
 355          // should be unique enough. Add one random part at the end
 356          $this->backupid = md5(time() . '-' . $this->type . '-' . $this->id . '-' . $this->format . '-' .
 357                                $this->interactive . '-' . $this->mode . '-' . $this->userid . '-' .
 358                                $this->operation . '-' . random_string(20));
 359      }
 360  
 361      protected function load_plan() {
 362          $this->log('loading controller plan', backup::LOG_DEBUG);
 363          $this->plan = new backup_plan($this);
 364          $this->plan->build(); // Build plan for this controller
 365          $this->set_status(backup::STATUS_PLANNED);
 366      }
 367  
 368      protected function apply_defaults() {
 369          $this->log('applying plan defaults', backup::LOG_DEBUG);
 370          backup_controller_dbops::apply_config_defaults($this);
 371          $this->set_status(backup::STATUS_CONFIGURED);
 372          $this->set_include_files();
 373      }
 374  
 375      /**
 376       * Set the initial value for the include_files setting.
 377       *
 378       * @see backup_controller::get_include_files for further information on the purpose of this setting.
 379       * @return int Indicates whether files should be included in backups.
 380       */
 381      protected function set_include_files() {
 382          // We normally include files.
 383          $includefiles = true;
 384  
 385          // In an import, we don't need to include files.
 386          if ($this->get_mode() === backup::MODE_IMPORT) {
 387              $includefiles = false;
 388          }
 389  
 390          // When a backup is intended for the same site, we don't need to include the files.
 391          // Note, this setting is only used for duplication of an entire course.
 392          if ($this->get_mode() === backup::MODE_SAMESITE) {
 393              $includefiles = false;
 394          }
 395  
 396          $this->includefiles = (int) $includefiles;
 397          $this->log("setting file inclusion to {$this->includefiles}", backup::LOG_DEBUG);
 398          return $this->includefiles;
 399      }
 400  }
 401  
 402  /*
 403   * Exception class used by all the @backup_controller stuff
 404   */
 405  class backup_controller_exception extends backup_exception {
 406  
 407      public function __construct($errorcode, $a=NULL, $debuginfo=null) {
 408          parent::__construct($errorcode, $a, $debuginfo);
 409      }
 410  }