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\Traits\Iterator\IteratorTrait;
  13 use Org\Mxchange\CoreFramework\Visitor\Visitable;
  14 use Org\Mxchange\CoreFramework\Visitor\Visitor;
  15
  16 /**
  17  * A Task handler
  18  *
  19  * @author              Roland Haeder <webmaster@shipsimu.org>
  20  * @version             0.0.0
  21  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2020 Core Developer Team
  22  * @license             GNU GPL 3.0 or any newer version
  23  * @link                http://www.shipsimu.org
  24  *
  25  * This program is free software: you can redistribute it and/or modify
  26  * it under the terms of the GNU General Public License as published by
  27  * the Free Software Foundation, either version 3 of the License, or
  28  * (at your option) any later version.
  29  *
  30  * This program is distributed in the hope that it will be useful,
  31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  33  * GNU General Public License for more details.
  34  *
  35  * You should have received a copy of the GNU General Public License
  36  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  37  */
  38 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
  39         // Load traits
  40         use IteratorTrait;
  41
  42         // Exception constants
  43         const EXCEPTION_TASK_IS_INVALID = 0xb00;
  44
  45         /**
  46          * Visitor handler instance
  47          */
  48         private $visitorInstance = NULL;
  49
  50         /**
  51          * Instance of the list
  52          */
  53         private $listInstance = NULL;
  54
  55         /**
  56          * Protected constructor
  57          *
  58          * @return      void
  59          */
  60         protected function __construct () {
  61                 // Call parent constructor
  62                 parent::__construct(__CLASS__);
  63
  64                 // Set handler name
  65                 $this->setHandlerName('task');
  66         }
  67
  68         /**
  69          * Creates an instance of this class
  70          *
  71          * @return      $handlerInstance        An instance of a HandleableTask class
  72          */
  73         public static final function createTaskHandler () {
  74                 // Get new instance
  75                 $handlerInstance = new TaskHandler();
  76
  77                 // Output debug message
  78                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Initializing task handler.');
  79
  80                 // Init the task list
  81                 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
  82
  83                 // Get default instance
  84                 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
  85
  86                 // Init visitor instance for faster loop
  87                 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
  88
  89                 // Register the first (and generic) idle-loop task
  90                 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
  91                 $handlerInstance->registerTask('idle_loop', $taskInstance);
  92
  93                 // Output debug message
  94                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task handler initialized.');
  95
  96                 // Return the prepared instance
  97                 return $handlerInstance;
  98         }
  99
 100         /**
 101          * Setter for visitor instance
 102          *
 103          * @param       $visitorInstance        An instance of a Visitor class
 104          * @return      void
 105          */
 106         protected final function setVisitorInstance (Visitor $visitorInstance) {
 107                 $this->visitorInstance = $visitorInstance;
 108         }
 109
 110         /**
 111          * Getter for visitor instance
 112          *
 113          * @return      $visitorInstance        An instance of a Visitor class
 114          */
 115         protected final function getVisitorInstance () {
 116                 return $this->visitorInstance;
 117         }
 118
 119         /**
 120          * Setter for the list instance
 121          *
 122          * @param       $listInstance   A list of Listable
 123          * @return      void
 124          */
 125         protected final function setListInstance (Listable $listInstance) {
 126                 $this->listInstance = $listInstance;
 127         }
 128
 129         /**
 130          * Getter for the list instance
 131          *
 132          * @return      $listInstance   A list of Listable
 133          */
 134         protected final function getListInstance () {
 135                 return $this->listInstance;
 136         }
 137
 138         /**
 139          * Tries to execute the given task. If as task should not be started (yet)
 140          * or the interval time (see task_interval_delay) is not yet reached the
 141          * task is quietly skipped.
 142          *
 143          * @return      void
 144          * @throws      InvalidTaskException    If the current task is invalid
 145          */
 146         private function executeCurrentTask () {
 147                 // Update no task by default
 148                 $updateTask = false;
 149
 150                 // Is the current task valid?
 151                 if (!$this->getListInstance()->getIterator()->valid()) {
 152                         // Not valid!
 153                         throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
 154                 } // END - if
 155
 156                 // Get current task
 157                 $currentTask = $this->getListInstance()->getIterator()->current();
 158
 159                 // Is the task not yet started?
 160                 if ($currentTask['task_started'] === false) {
 161                         // Determine difference between current time and registration
 162                         $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
 163
 164                         // Should we start now?
 165                         if ($diff < $currentTask['task_startup_delay']) {
 166                                 // Skip this silently
 167                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' not started: diff=' . $diff . ',task_startup_delay=' . $currentTask['task_startup_delay']);
 168                                 return;
 169                         } // END - if
 170
 171                         // Launch the task and mark it as updated
 172                         $currentTask['task_started'] = true;
 173                         $updateTask = true;
 174
 175                         // Debug message
 176                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
 177                 } // END - if
 178
 179                 // Get time difference from interval delay
 180                 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
 181
 182                 // Debug message
 183                 //* 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=' . $currentTask['task_total_runs']);
 184
 185                 // Is the interval delay reached?
 186                 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_max_runs'] > 0) && ($currentTask['task_total_runs'] == $currentTask['task_max_runs']))) {
 187                         // Should we update the task from startup?
 188                         if ($updateTask === true) {
 189                                 // Update the task before leaving
 190                                 $this->updateTask($currentTask);
 191                         } // END - if
 192
 193                         // Skip this silently
 194                         return;
 195                 } // END - if
 196
 197                 // Set last activity
 198                 $currentTask['task_last_activity'] = $this->getMilliTime();
 199
 200                 // Count this run
 201                 $currentTask['task_total_runs']++;
 202
 203                 // Update the task
 204                 $this->updateTask($currentTask);
 205
 206                 // And visit/run it
 207                 // @TODO Messurement can be added around this call
 208                 $currentTask['task_instance']->accept($this->getVisitorInstance());
 209         }
 210
 211         /**
 212          * Updates given task by updating the underlaying list
 213          *
 214          * @param       $taskEntry      An array with a task
 215          * @return      void
 216          */
 217         private function updateTask (array $taskEntry) {
 218                 // Get the key from current iteration
 219                 $key = $this->getListInstance()->getIterator()->key();
 220
 221                 // Get the hash from key
 222                 $hash = $this->getListInstance()->getHash($key);
 223
 224                 // Update the entry
 225                 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
 226         }
 227
 228         /**
 229          * Unregisters the given task
 230          *
 231          * @param       $taskData       Data of the task
 232          * @return      void
 233          */
 234         private function unregisterTask (array $taskData) {
 235                 // Debug output
 236                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
 237
 238                 // Remove the entry
 239                 $this->getListInstance()->removeEntry('tasks', $taskData);
 240
 241                 // Debug output
 242                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
 243          }
 244
 245         /**
 246          * Searches a task by given instance
 247          *
 248          * @param       $taskInstanc    An instanceof a Taskable class
 249          * @return      $taskName               Name of the task as used while registration
 250          */
 251         public function searchTask (Taskable $taskInstance) {
 252                 // Default is an empty (not found) task name
 253                 $taskName = '';
 254
 255                 // Get whole list
 256                 $taskList = $this->getListInstance()->getArrayFromList('tasks');
 257
 258                 // Search all instances
 259                 foreach ($taskList as $currentTask) {
 260                         // Does it match given task instance?
 261                         if ($currentTask['task_instance']->equals($taskInstance)) {
 262                                 // Found it
 263                                 $taskName = $currentTask['id'];
 264
 265                                 // Abort here
 266                                 break;
 267                         } // END - if
 268                 } // END - foreach
 269
 270                 // Return found name
 271                 return $taskName;
 272         }
 273
 274         /**
 275          * Registers a task with a task handler.
 276          *
 277          * @param       $taskName               A task name to register the task on
 278          * @param       $taskInstance   The instance that should be registered as a task
 279          * @return      void
 280          */
 281         public function registerTask ($taskName, Visitable $taskInstance) {
 282                 // Get interval delay
 283                 $intervalDelay = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_interval_delay');
 284                 $startupDelay  = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_startup_delay');
 285
 286                 // If the task is 'idle_loop', a deplay of zero seconds is fine
 287                 assert($intervalDelay >= 0);
 288                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($intervalDelay > 0)));
 289                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($startupDelay > 0)));
 290
 291                 // Create the entry
 292                 $taskEntry = array(
 293                         // Identifier for the generateHash() method
 294                         'id'                  => $taskName,
 295                         // Whether the task is started
 296                         'task_started'        => false,
 297                         // Whether the task is paused (not yet implemented)
 298                         'task_paused'         => false,
 299                         // Whether the task can be paused (not yet implemented)
 300                         'task_pauseable'      => true,
 301                         // Timestamp of registration
 302                         'task_registered'     => $this->getMilliTime(),
 303                         // Last activity timestamp
 304                         'task_last_activity'  => 0,
 305                         // Total runs of this task
 306                         'task_total_runs'     => 0,
 307                         // Task instance itself
 308                         'task_instance'       => $taskInstance,
 309                         // Startup delay in milliseconds
 310                         'task_startup_delay'  => $startupDelay,
 311                         // Interval time (delay) in milliseconds before this task is executed again
 312                         'task_interval_delay' => $intervalDelay,
 313                         // How often should this task run?
 314                         'task_max_runs'       => FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
 315                 );
 316
 317                 // Add the entry
 318                 $this->getListInstance()->addEntry('tasks', $taskEntry);
 319
 320                 // Debug message
 321                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task registered: taskName=' . $taskName .
 322                         ' (taskInstance=' . $taskInstance->__toString() . ')' .
 323                         ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
 324                         ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
 325                         ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
 326                 );
 327         }
 328
 329         /**
 330          * Checks whether tasks are left including idle task
 331          *
 332          * @return      $tasksLeft      Whether there are tasks left to handle
 333          */
 334         public function hasTasksLeft () {
 335                 // Do we have tasks there?
 336                 $tasksLeft = ($this->getListInstance()->count() > 0);
 337
 338                 // Return result
 339                 return $tasksLeft;
 340         }
 341
 342         /**
 343          * Handles all tasks by checking if they should startup or if it is their
 344          * turn to run. You should use this method in a while() loop in conjuntion
 345          * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
 346          * which will attempt to remove all tasks from the task handler.
 347          *
 348          * @return      void
 349          */
 350         public function handleTasks () {
 351                 // Should we rewind?
 352                 if (!$this->getListInstance()->getIterator()->valid()) {
 353                         // Rewind to the beginning for next loop
 354                         $this->getListInstance()->getIterator()->rewind();
 355                 } // END - if
 356
 357                 // Try to execute the task
 358                 $this->executeCurrentTask();
 359
 360                 // Go to next entry
 361                 $this->getListInstance()->getIterator()->next();
 362         }
 363
 364         /**
 365          * Shuts down all tasks and the task handler itself. This method should be
 366          * called from a corresponding filter class.
 367          *
 368          * @return      void
 369          */
 370         public function doShutdown () {
 371                 // Always rewind to the beginning for next loop
 372                 $this->getListInstance()->getIterator()->rewind();
 373
 374                 // Debug message
 375                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
 376
 377                 // Remember all tasks that has been shutdown for removal
 378                 $tasks = [];
 379
 380                 // Instance a visitor
 381                 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
 382
 383                 // Shutdown all tasks in once go
 384                 while ($this->getListInstance()->getIterator()->valid()) {
 385                         // Get current entry
 386                         $currentTask = $this->getListInstance()->getIterator()->current();
 387
 388                         // Output debug message
 389                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
 390
 391                         // Shutdown the task
 392                         $currentTask['task_instance']->accept($this->getVisitorInstance());
 393
 394                         // Remember this task
 395                         array_push($tasks, $currentTask);
 396
 397                         // Advance to next one
 398                         $this->getListInstance()->getIterator()->next();
 399                 } // END - while
 400
 401                 // Debug message
 402                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutdown of all tasks completed.');
 403
 404                 // Remove all tasks
 405                 foreach ($tasks as $entry) {
 406                         $this->unregisterTask($entry);
 407                 } // END - foreach
 408         }
 409
 410 }