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