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