framework/main/classes/handler/tasks/class_TaskHandler.php

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Handler\Task;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
   7 use Org\Mxchange\CoreFramework\Factory\ObjectFactory;
   8 use Org\Mxchange\CoreFramework\Handler\BaseHandler;
   9 use Org\Mxchange\CoreFramework\Lists\Listable;
  10 use Org\Mxchange\CoreFramework\Registry\Registerable;
  11 use Org\Mxchange\CoreFramework\Task\Taskable;
  12 use Org\Mxchange\CoreFramework\Visitor\Visitable;
  13 use Org\Mxchange\CoreFramework\Visitor\Visitor;
  14
  15 /**
  16  * A Task handler
  17  *
  18  * @author              Roland Haeder <webmaster@shipsimu.org>
  19  * @version             0.0.0
  20  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2020 Core Developer Team
  21  * @license             GNU GPL 3.0 or any newer version
  22  * @link                http://www.shipsimu.org
  23  *
  24  * This program is free software: you can redistribute it and/or modify
  25  * it under the terms of the GNU General Public License as published by
  26  * the Free Software Foundation, either version 3 of the License, or
  27  * (at your option) any later version.
  28  *
  29  * This program is distributed in the hope that it will be useful,
  30  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  31  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  32  * GNU General Public License for more details.
  33  *
  34  * You should have received a copy of the GNU General Public License
  35  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  36  */
  37 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
  38         // Exception constants
  39         const EXCEPTION_TASK_IS_INVALID = 0xb00;
  40
  41         /**
  42          * Visitor handler instance
  43          */
  44         private $visitorInstance = NULL;
  45
  46         /**
  47          * Instance of the list
  48          */
  49         private $listInstance = NULL;
  50
  51         /**
  52          * Protected constructor
  53          *
  54          * @return      void
  55          */
  56         protected function __construct () {
  57                 // Call parent constructor
  58                 parent::__construct(__CLASS__);
  59
  60                 // Set handler name
  61                 $this->setHandlerName('task');
  62         }
  63
  64         /**
  65          * Creates an instance of this class
  66          *
  67          * @return      $handlerInstance        An instance of a HandleableTask class
  68          */
  69         public static final function createTaskHandler () {
  70                 // Get new instance
  71                 $handlerInstance = new TaskHandler();
  72
  73                 // Output debug message
  74                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Initializing task handler.');
  75
  76                 // Init the task list
  77                 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
  78
  79                 // Get default instance
  80                 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
  81
  82                 // Init visitor instance for faster loop
  83                 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
  84
  85                 // Register the first (and generic) idle-loop task
  86                 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
  87                 $handlerInstance->registerTask('idle_loop', $taskInstance);
  88
  89                 // Output debug message
  90                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task handler initialized.');
  91
  92                 // Return the prepared instance
  93                 return $handlerInstance;
  94         }
  95
  96         /**
  97          * Setter for visitor instance
  98          *
  99          * @param       $visitorInstance        An instance of a Visitor class
 100          * @return      void
 101          */
 102         protected final function setVisitorInstance (Visitor $visitorInstance) {
 103                 $this->visitorInstance = $visitorInstance;
 104         }
 105
 106         /**
 107          * Getter for visitor instance
 108          *
 109          * @return      $visitorInstance        An instance of a Visitor class
 110          */
 111         protected final function getVisitorInstance () {
 112                 return $this->visitorInstance;
 113         }
 114
 115         /**
 116          * Setter for the list instance
 117          *
 118          * @param       $listInstance   A list of Listable
 119          * @return      void
 120          */
 121         protected final function setListInstance (Listable $listInstance) {
 122                 $this->listInstance = $listInstance;
 123         }
 124
 125         /**
 126          * Getter for the list instance
 127          *
 128          * @return      $listInstance   A list of Listable
 129          */
 130         protected final function getListInstance () {
 131                 return $this->listInstance;
 132         }
 133
 134         /**
 135          * Tries to execute the given task. If as task should not be started (yet)
 136          * or the interval time (see task_interval_delay) is not yet reached the
 137          * task is quietly skipped.
 138          *
 139          * @return      void
 140          * @throws      InvalidTaskException    If the current task is invalid
 141          */
 142         private function executeCurrentTask () {
 143                 // Update no task by default
 144                 $updateTask = false;
 145
 146                 // Is the current task valid?
 147                 if (!$this->getListInstance()->getIterator()->valid()) {
 148                         // Not valid!
 149                         throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
 150                 } // END - if
 151
 152                 // Get current task
 153                 $currentTask = $this->getListInstance()->getIterator()->current();
 154
 155                 // Is the task not yet started?
 156                 if ($currentTask['task_started'] === false) {
 157                         // Determine difference between current time and registration
 158                         $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
 159
 160                         // Should we start now?
 161                         if ($diff < $currentTask['task_startup_delay']) {
 162                                 // Skip this silently
 163                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' not started: diff=' . $diff . ',task_startup_delay=' . $currentTask['task_startup_delay']);
 164                                 return;
 165                         } // END - if
 166
 167                         // Launch the task and mark it as updated
 168                         $currentTask['task_started'] = true;
 169                         $updateTask = true;
 170
 171                         // Debug message
 172                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
 173                 } // END - if
 174
 175                 // Get time difference from interval delay
 176                 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
 177
 178                 // Debug message
 179                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' diff=' . $diff . ',task_interval_delay=' . $currentTask['task_interval_delay'] . ',task_max_runs=' . $currentTask['task_max_runs'] . ',task_total_runs=' . $currentTask['task_total_runs']);
 180
 181                 // Is the interval delay reached?
 182                 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_max_runs'] > 0) && ($currentTask['task_total_runs'] == $currentTask['task_max_runs']))) {
 183                         // Should we update the task from startup?
 184                         if ($updateTask === true) {
 185                                 // Update the task before leaving
 186                                 $this->updateTask($currentTask);
 187                         } // END - if
 188
 189                         // Skip this silently
 190                         return;
 191                 } // END - if
 192
 193                 // Set last activity
 194                 $currentTask['task_last_activity'] = $this->getMilliTime();
 195
 196                 // Count this run
 197                 $currentTask['task_total_runs']++;
 198
 199                 // Update the task
 200                 $this->updateTask($currentTask);
 201
 202                 // And visit/run it
 203                 // @TODO Messurement can be added around this call
 204                 $currentTask['task_instance']->accept($this->getVisitorInstance());
 205         }
 206
 207         /**
 208          * Updates given task by updating the underlaying list
 209          *
 210          * @param       $taskEntry      An array with a task
 211          * @return      void
 212          */
 213         private function updateTask (array $taskEntry) {
 214                 // Get the key from current iteration
 215                 $key = $this->getListInstance()->getIterator()->key();
 216
 217                 // Get the hash from key
 218                 $hash = $this->getListInstance()->getHash($key);
 219
 220                 // Update the entry
 221                 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
 222         }
 223
 224         /**
 225          * Unregisters the given task
 226          *
 227          * @param       $taskData       Data of the task
 228          * @return      void
 229          */
 230         private function unregisterTask (array $taskData) {
 231                 // Debug output
 232                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
 233
 234                 // Remove the entry
 235                 $this->getListInstance()->removeEntry('tasks', $taskData);
 236
 237                 // Debug output
 238                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
 239          }
 240
 241         /**
 242          * Searches a task by given instance
 243          *
 244          * @param       $taskInstanc    An instanceof a Taskable class
 245          * @return      $taskName               Name of the task as used while registration
 246          */
 247         public function searchTask (Taskable $taskInstance) {
 248                 // Default is an empty (not found) task name
 249                 $taskName = '';
 250
 251                 // Get whole list
 252                 $taskList = $this->getListInstance()->getArrayFromList('tasks');
 253
 254                 // Search all instances
 255                 foreach ($taskList as $currentTask) {
 256                         // Does it match given task instance?
 257                         if ($currentTask['task_instance']->equals($taskInstance)) {
 258                                 // Found it
 259                                 $taskName = $currentTask['id'];
 260
 261                                 // Abort here
 262                                 break;
 263                         } // END - if
 264                 } // END - foreach
 265
 266                 // Return found name
 267                 return $taskName;
 268         }
 269
 270         /**
 271          * Registers a task with a task handler.
 272          *
 273          * @param       $taskName               A task name to register the task on
 274          * @param       $taskInstance   The instance that should be registered as a task
 275          * @return      void
 276          */
 277         public function registerTask ($taskName, Visitable $taskInstance) {
 278                 // Get interval delay
 279                 $intervalDelay = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_interval_delay');
 280                 $startupDelay  = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_startup_delay');
 281
 282                 // If the task is 'idle_loop', a deplay of zero seconds is fine
 283                 assert($intervalDelay >= 0);
 284                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($intervalDelay > 0)));
 285                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($startupDelay > 0)));
 286
 287                 // Create the entry
 288                 $taskEntry = array(
 289                         // Identifier for the generateHash() method
 290                         'id'                  => $taskName,
 291                         // Whether the task is started
 292                         'task_started'        => false,
 293                         // Whether the task is paused (not yet implemented)
 294                         'task_paused'         => false,
 295                         // Whether the task can be paused (not yet implemented)
 296                         'task_pauseable'      => true,
 297                         // Timestamp of registration
 298                         'task_registered'     => $this->getMilliTime(),
 299                         // Last activity timestamp
 300                         'task_last_activity'  => 0,
 301                         // Total runs of this task
 302                         'task_total_runs'     => 0,
 303                         // Task instance itself
 304                         'task_instance'       => $taskInstance,
 305                         // Startup delay in milliseconds
 306                         'task_startup_delay'  => $startupDelay,
 307                         // Interval time (delay) in milliseconds before this task is executed again
 308                         'task_interval_delay' => $intervalDelay,
 309                         // How often should this task run?
 310                         'task_max_runs'       => FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
 311                 );
 312
 313                 // Add the entry
 314                 $this->getListInstance()->addEntry('tasks', $taskEntry);
 315
 316                 // Debug message
 317                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task registered: taskName=' . $taskName .
 318                         ' (taskInstance=' . $taskInstance->__toString() . ')' .
 319                         ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
 320                         ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
 321                         ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
 322                 );
 323         }
 324
 325         /**
 326          * Checks whether tasks are left including idle task
 327          *
 328          * @return      $tasksLeft      Whether there are tasks left to handle
 329          */
 330         public function hasTasksLeft () {
 331                 // Do we have tasks there?
 332                 $tasksLeft = ($this->getListInstance()->count() > 0);
 333
 334                 // Return result
 335                 return $tasksLeft;
 336         }
 337
 338         /**
 339          * Handles all tasks by checking if they should startup or if it is their
 340          * turn to run. You should use this method in a while() loop in conjuntion
 341          * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
 342          * which will attempt to remove all tasks from the task handler.
 343          *
 344          * @return      void
 345          */
 346         public function handleTasks () {
 347                 // Should we rewind?
 348                 if (!$this->getListInstance()->getIterator()->valid()) {
 349                         // Rewind to the beginning for next loop
 350                         $this->getListInstance()->getIterator()->rewind();
 351                 } // END - if
 352
 353                 // Try to execute the task
 354                 $this->executeCurrentTask();
 355
 356                 // Go to next entry
 357                 $this->getListInstance()->getIterator()->next();
 358         }
 359
 360         /**
 361          * Shuts down all tasks and the task handler itself. This method should be
 362          * called from a corresponding filter class.
 363          *
 364          * @return      void
 365          */
 366         public function doShutdown () {
 367                 // Always rewind to the beginning for next loop
 368                 $this->getListInstance()->getIterator()->rewind();
 369
 370                 // Debug message
 371                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
 372
 373                 // Remember all tasks that has been shutdown for removal
 374                 $tasks = [];
 375
 376                 // Instance a visitor
 377                 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
 378
 379                 // Shutdown all tasks in once go
 380                 while ($this->getListInstance()->getIterator()->valid()) {
 381                         // Get current entry
 382                         $currentTask = $this->getListInstance()->getIterator()->current();
 383
 384                         // Output debug message
 385                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
 386
 387                         // Shutdown the task
 388                         $currentTask['task_instance']->accept($this->getVisitorInstance());
 389
 390                         // Remember this task
 391                         array_push($tasks, $currentTask);
 392
 393                         // Advance to next one
 394                         $this->getListInstance()->getIterator()->next();
 395                 } // END - while
 396
 397                 // Debug message
 398                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutdown of all tasks completed.');
 399
 400                 // Remove all tasks
 401                 foreach ($tasks as $entry) {
 402                         $this->unregisterTask($entry);
 403                 } // END - foreach
 404         }
 405
 406 }