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