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\Factory\ObjectFactory;
   7 use Org\Mxchange\CoreFramework\Handler\BaseHandler;
   8 use Org\Mxchange\CoreFramework\Lists\Listable;
   9 use Org\Mxchange\CoreFramework\Registry\Registerable;
  10 use Org\Mxchange\CoreFramework\Task\Taskable;
  11 use Org\Mxchange\CoreFramework\Visitor\Visitable;
  12
  13 /**
  14  * A Task handler
  15  *
  16  * @author              Roland Haeder <webmaster@shipsimu.org>
  17  * @version             0.0.0
  18 <<<<<<< HEAD:framework/main/classes/handler/tasks/class_TaskHandler.php
  19  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  20 =======
  21  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2016 Core Developer Team
  22 >>>>>>> Some updates::inc/main/classes/handler/tasks/class_TaskHandler.php
  23  * @license             GNU GPL 3.0 or any newer version
  24  * @link                http://www.shipsimu.org
  25  *
  26  * This program is free software: you can redistribute it and/or modify
  27  * it under the terms of the GNU General Public License as published by
  28  * the Free Software Foundation, either version 3 of the License, or
  29  * (at your option) any later version.
  30  *
  31  * This program is distributed in the hope that it will be useful,
  32  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  33  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  34  * GNU General Public License for more details.
  35  *
  36  * You should have received a copy of the GNU General Public License
  37  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  38  */
  39 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
  40         // Exception constants
  41         const EXCEPTION_TASK_IS_INVALID = 0xb00;
  42
  43         /**
  44          * Protected constructor
  45          *
  46          * @return      void
  47          */
  48         protected function __construct () {
  49                 // Call parent constructor
  50                 parent::__construct(__CLASS__);
  51
  52                 // Set handler name
  53                 $this->setHandlerName('task');
  54         }
  55
  56         /**
  57          * Creates an instance of this class
  58          *
  59          * @return      $handlerInstance        An instance of a HandleableTask class
  60          */
  61         public static final function createTaskHandler () {
  62                 // Get new instance
  63                 $handlerInstance = new TaskHandler();
  64
  65                 // Output debug message
  66                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Initializing task handler.');
  67
  68                 // Init the task list
  69                 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
  70
  71                 // Get default instance
  72                 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
  73
  74                 // Init visitor instance for faster loop
  75                 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
  76
  77                 // Register the first (and generic) idle-loop task
  78                 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
  79                 $handlerInstance->registerTask('idle_loop', $taskInstance);
  80
  81                 // Output debug message
  82                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task handler initialized.');
  83
  84                 // Return the prepared instance
  85                 return $handlerInstance;
  86         }
  87
  88         /**
  89          * Tries to execute the given task. If as task should not be started (yet)
  90          * or the interval time (see task_interval_delay) is not yet reached the
  91          * task is quietly skipped.
  92          *
  93          * @return      void
  94          * @throws      InvalidTaskException    If the current task is invalid
  95          */
  96         private function executeCurrentTask () {
  97                 // Update no task by default
  98                 $updateTask = false;
  99
 100                 // Is the current task valid?
 101                 if (!$this->getListInstance()->getIterator()->valid()) {
 102                         // Not valid!
 103                         throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
 104                 } // END - if
 105
 106                 // Get current task
 107                 $currentTask = $this->getListInstance()->getIterator()->current();
 108
 109                 // Is the task not yet started?
 110                 if ($currentTask['task_started'] === false) {
 111                         // Determine difference between current time and registration
 112                         $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
 113
 114                         // Should we start now?
 115                         if ($diff < $currentTask['task_startup_delay']) {
 116                                 // Skip this silently
 117                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task ' . $currentTask['id'] . ' not started: diff=' . $diff . ',task_startup_delay=' . $currentTask['task_startup_delay']);
 118                                 return;
 119                         } // END - if
 120
 121                         // Launch the task and mark it as updated
 122                         $currentTask['task_started'] = true;
 123                         $updateTask = true;
 124
 125                         // Debug message
 126                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
 127                 } // END - if
 128
 129                 // Get time difference from interval delay
 130                 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
 131
 132                 // Debug message
 133                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task ' . $currentTask['id'] . ' diff=' . $diff . ',task_interval_delay=' . $currentTask['task_interval_delay'] . ',task_max_runs=' . $currentTask['task_max_runs'] . ',task_total_runs=' . $currentTask['task_total_runs']);
 134
 135                 // Is the interval delay reached?
 136                 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_max_runs'] > 0) && ($currentTask['task_total_runs'] == $currentTask['task_max_runs']))) {
 137                         // Should we update the task from startup?
 138                         if ($updateTask === true) {
 139                                 // Update the task before leaving
 140                                 $this->updateTask($currentTask);
 141                         } // END - if
 142
 143                         // Skip this silently
 144                         return;
 145                 } // END - if
 146
 147                 // Set last activity
 148                 $currentTask['task_last_activity'] = $this->getMilliTime();
 149
 150                 // Count this run
 151                 $currentTask['task_total_runs']++;
 152
 153                 // Update the task
 154                 $this->updateTask($currentTask);
 155
 156                 // And visit/run it
 157                 // @TODO Messurement can be added around this call
 158                 $currentTask['task_instance']->accept($this->getVisitorInstance());
 159         }
 160
 161         /**
 162          * Updates given task by updating the underlaying list
 163          *
 164          * @param       $taskEntry      An array with a task
 165          * @return      void
 166          */
 167         private function updateTask (array $taskEntry) {
 168                 // Get the key from current iteration
 169                 $key = $this->getListInstance()->getIterator()->key();
 170
 171                 // Get the hash from key
 172                 $hash = $this->getListInstance()->getHash($key);
 173
 174                 // Update the entry
 175                 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
 176         }
 177
 178         /**
 179          * Unregisters the given task
 180          *
 181          * @param       $taskData       Data of the task
 182          * @return      void
 183          */
 184         private function unregisterTask (array $taskData) {
 185                 // Debug output
 186                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
 187
 188                 // Remove the entry
 189                 $this->getListInstance()->removeEntry('tasks', $taskData);
 190
 191                 // Debug output
 192                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
 193          }
 194
 195         /**
 196          * Searches a task by given instance
 197          *
 198          * @param       $taskInstanc    An instanceof a Taskable class
 199          * @return      $taskName               Name of the task as used while registration
 200          */
 201         public function searchTask (Taskable $taskInstance) {
 202                 // Default is an empty (not found) task name
 203                 $taskName = '';
 204
 205                 // Get whole list
 206                 $taskList = $this->getListInstance()->getArrayFromList('tasks');
 207
 208                 // Search all instances
 209                 foreach ($taskList as $currentTask) {
 210                         // Does it match given task instance?
 211                         if ($currentTask['task_instance']->equals($taskInstance)) {
 212                                 // Found it
 213                                 $taskName = $currentTask['id'];
 214
 215                                 // Abort here
 216                                 break;
 217                         } // END - if
 218                 } // END - foreach
 219
 220                 // Return found name
 221                 return $taskName;
 222         }
 223
 224         /**
 225          * Registers a task with a task handler.
 226          *
 227          * @param       $taskName               A task name to register the task on
 228          * @param       $taskInstance   The instance that should be registered as a task
 229          * @return      void
 230          */
 231         public function registerTask ($taskName, Visitable $taskInstance) {
 232                 // Get interval delay
 233                 $intervalDelay = $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay');
 234                 $startupDelay  = $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay');
 235
 236                 // If the task is 'idle_loop', a deplay of zero seconds is fine
 237                 assert($intervalDelay >= 0);
 238                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($intervalDelay > 0)));
 239                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($startupDelay > 0)));
 240
 241                 // Create the entry
 242                 $taskEntry = array(
 243                         // Identifier for the generateHash() method
 244                         'id'                  => $taskName,
 245                         // Whether the task is started
 246                         'task_started'        => false,
 247                         // Whether the task is paused (not yet implemented)
 248                         'task_paused'         => false,
 249                         // Whether the task can be paused (not yet implemented)
 250                         'task_pauseable'      => true,
 251                         // Timestamp of registration
 252                         'task_registered'     => $this->getMilliTime(),
 253                         // Last activity timestamp
 254                         'task_last_activity'  => 0,
 255                         // Total runs of this task
 256                         'task_total_runs'     => 0,
 257                         // Task instance itself
 258                         'task_instance'       => $taskInstance,
 259                         // Startup delay in milliseconds
 260                         'task_startup_delay'  => $startupDelay,
 261                         // Interval time (delay) in milliseconds before this task is executed again
 262                         'task_interval_delay' => $intervalDelay,
 263                         // How often should this task run?
 264                         'task_max_runs'       => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
 265                 );
 266
 267                 // Add the entry
 268                 $this->getListInstance()->addEntry('tasks', $taskEntry);
 269
 270                 // Debug message
 271                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task registered: taskName=' . $taskName .
 272                         ' (taskInstance=' . $taskInstance->__toString() . ')' .
 273                         ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
 274                         ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
 275                         ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
 276                 );
 277         }
 278
 279         /**
 280          * Checks whether tasks are left including idle task
 281          *
 282          * @return      $tasksLeft      Whether there are tasks left to handle
 283          */
 284         public function hasTasksLeft () {
 285                 // Do we have tasks there?
 286                 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
 287
 288                 // Return result
 289                 return $tasksLeft;
 290         }
 291
 292         /**
 293          * Handles all tasks by checking if they should startup or if it is their
 294          * turn to run. You should use this method in a while() loop in conjuntion
 295          * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
 296          * which will attempt to remove all tasks from the task handler.
 297          *
 298          * @return      void
 299          */
 300         public function handleTasks () {
 301                 // Should we rewind?
 302                 if (!$this->getListInstance()->getIterator()->valid()) {
 303                         // Rewind to the beginning for next loop
 304                         $this->getListInstance()->getIterator()->rewind();
 305                 } // END - if
 306
 307                 // Try to execute the task
 308                 $this->executeCurrentTask();
 309
 310                 // Go to next entry
 311                 $this->getListInstance()->getIterator()->next();
 312         }
 313
 314         /**
 315          * Shuts down all tasks and the task handler itself. This method should be
 316          * called from a corresponding filter class.
 317          *
 318          * @return      void
 319          */
 320         public function doShutdown () {
 321                 // Always rewind to the beginning for next loop
 322                 $this->getListInstance()->getIterator()->rewind();
 323
 324                 // Debug message
 325                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
 326
 327                 // Remember all tasks that has been shutdown for removal
 328                 $tasks = array();
 329
 330                 // Instance a visitor
 331                 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
 332
 333                 // Shutdown all tasks in once go
 334                 while ($this->getListInstance()->getIterator()->valid()) {
 335                         // Get current entry
 336                         $currentTask = $this->getListInstance()->getIterator()->current();
 337
 338                         // Output debug message
 339                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
 340
 341                         // Shutdown the task
 342                         $currentTask['task_instance']->accept($this->getVisitorInstance());
 343
 344                         // Remember this task
 345                         array_push($tasks, $currentTask);
 346
 347                         // Advance to next one
 348                         $this->getListInstance()->getIterator()->next();
 349                 } // END - while
 350
 351                 // Debug message
 352                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutdown of all tasks completed.');
 353
 354                 // Remove all tasks
 355                 foreach ($tasks as $entry) {
 356                         $this->unregisterTask($entry);
 357                 } // END - foreach
 358         }
 359
 360 }