inc/main/classes/handler/tasks/class_TaskHandler.php

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Handler\Task;
   4
   5 // Import framework stuff
   6 use CoreFramework\Factory\ObjectFactory;
   7 use CoreFramework\Registry\Registerable;
   8
   9 /**
  10  * A Task handler
  11  *
  12  * @author              Roland Haeder <webmaster@shipsimu.org>
  13  * @version             0.0.0
  14  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  15  * @license             GNU GPL 3.0 or any newer version
  16  * @link                http://www.shipsimu.org
  17  *
  18  * This program is free software: you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation, either version 3 of the License, or
  21  * (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  30  */
  31 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
  32         // Exception constants
  33         const EXCEPTION_TASK_IS_INVALID = 0xb00;
  34
  35         /**
  36          * Protected constructor
  37          *
  38          * @return      void
  39          */
  40         protected function __construct () {
  41                 // Call parent constructor
  42                 parent::__construct(__CLASS__);
  43
  44                 // Set handler name
  45                 $this->setHandlerName('task');
  46         }
  47
  48         /**
  49          * Creates an instance of this class
  50          *
  51          * @return      $handlerInstance        An instance of a HandleableTask class
  52          */
  53         public static final function createTaskHandler () {
  54                 // Get new instance
  55                 $handlerInstance = new TaskHandler();
  56
  57                 // Output debug message
  58                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Initializing task handler.');
  59
  60                 // Init the task list
  61                 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
  62
  63                 // Get default instance
  64                 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
  65
  66                 // Init visitor instance for faster loop
  67                 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
  68
  69                 // Register the first (and generic) idle-loop task
  70                 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
  71                 $handlerInstance->registerTask('idle_loop', $taskInstance);
  72
  73                 // Output debug message
  74                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task handler initialized.');
  75
  76                 // Return the prepared instance
  77                 return $handlerInstance;
  78         }
  79
  80         /**
  81          * Tries to execute the given task. If as task should not be started (yet)
  82          * or the interval time (see task_interval_delay) is not yet reached the
  83          * task is quietly skipped.
  84          *
  85          * @return      void
  86          * @throws      InvalidTaskException    If the current task is invalid
  87          */
  88         private function executeCurrentTask () {
  89                 // Update no task by default
  90                 $updateTask = FALSE;
  91
  92                 // Is the current task valid?
  93                 if (!$this->getListInstance()->getIterator()->valid()) {
  94                         // Not valid!
  95                         throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
  96                 } // END - if
  97
  98                 // Get current task
  99                 $currentTask = $this->getListInstance()->getIterator()->current();
 100
 101                 // Is the task not yet started?
 102                 if ($currentTask['task_started'] === FALSE) {
 103                         // Determine difference between current time and registration
 104                         $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
 105
 106                         // Should we start now?
 107                         if ($diff < $currentTask['task_startup_delay']) {
 108                                 // Skip this silently
 109                                 //* 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']);
 110                                 return;
 111                         } // END - if
 112
 113                         // Launch the task and mark it as updated
 114                         $currentTask['task_started'] = TRUE;
 115                         $updateTask = TRUE;
 116
 117                         // Debug message
 118                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
 119                 } // END - if
 120
 121                 // Get time difference from interval delay
 122                 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
 123
 124                 // Debug message
 125                 //* 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=' . $currentTask['task_total_runs']);
 126
 127                 // Is the interval delay reached?
 128                 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_max_runs'] > 0) && ($currentTask['task_total_runs'] == $currentTask['task_max_runs']))) {
 129                         // Should we update the task from startup?
 130                         if ($updateTask === TRUE) {
 131                                 // Update the task before leaving
 132                                 $this->updateTask($currentTask);
 133                         } // END - if
 134
 135                         // Skip this silently
 136                         return;
 137                 } // END - if
 138
 139                 // Set last activity
 140                 $currentTask['task_last_activity'] = $this->getMilliTime();
 141
 142                 // Count this run
 143                 $currentTask['task_total_runs']++;
 144
 145                 // Update the task
 146                 $this->updateTask($currentTask);
 147
 148                 // And visit/run it
 149                 // @TODO Messurement can be added around this call
 150                 $currentTask['task_instance']->accept($this->getVisitorInstance());
 151         }
 152
 153         /**
 154          * Updates given task by updating the underlaying list
 155          *
 156          * @param       $taskEntry      An array with a task
 157          * @return      void
 158          */
 159         private function updateTask (array $taskEntry) {
 160                 // Get the key from current iteration
 161                 $key = $this->getListInstance()->getIterator()->key();
 162
 163                 // Get the hash from key
 164                 $hash = $this->getListInstance()->getHash($key);
 165
 166                 // Update the entry
 167                 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
 168         }
 169
 170         /**
 171          * Unregisters the given task
 172          *
 173          * @param       $taskData       Data of the task
 174          * @return      void
 175          */
 176         private function unregisterTask (array $taskData) {
 177                 // Debug output
 178                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
 179
 180                 // Remove the entry
 181                 $this->getListInstance()->removeEntry('tasks', $taskData);
 182
 183                 // Debug output
 184                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
 185          }
 186
 187         /**
 188          * Searches a task by given instance
 189          *
 190          * @param       $taskInstanc    An instanceof a Taskable class
 191          * @return      $taskName               Name of the task as used while registration
 192          */
 193         public function searchTask (Taskable $taskInstance) {
 194                 // Default is an empty (not found) task name
 195                 $taskName = '';
 196
 197                 // Get whole list
 198                 $taskList = $this->getListInstance()->getArrayFromList('tasks');
 199
 200                 // Search all instances
 201                 foreach ($taskList as $currentTask) {
 202                         // Does it match given task instance?
 203                         if ($currentTask['task_instance']->equals($taskInstance)) {
 204                                 // Found it
 205                                 $taskName = $currentTask['id'];
 206
 207                                 // Abort here
 208                                 break;
 209                         } // END - if
 210                 } // END - foreach
 211
 212                 // Return found name
 213                 return $taskName;
 214         }
 215
 216         /**
 217          * Registers a task with a task handler.
 218          *
 219          * @param       $taskName               A task name to register the task on
 220          * @param       $taskInstance   The instance we should register as a task
 221          * @return      void
 222          */
 223         public function registerTask ($taskName, Visitable $taskInstance) {
 224                 // Get interval delay
 225                 $intervalDelay = $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay');
 226                 $startupDelay  = $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay');
 227
 228                 // If the task is 'idle_loop', a deplay of zero seconds is fine
 229                 assert($intervalDelay >= 0);
 230                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($intervalDelay > 0)));
 231                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($startupDelay > 0)));
 232
 233                 // Create the entry
 234                 $taskEntry = array(
 235                         // Identifier for the generateHash() method
 236                         'id'                  => $taskName,
 237                         // Whether the task is started
 238                         'task_started'        => FALSE,
 239                         // Whether the task is paused (not yet implemented)
 240                         'task_paused'         => FALSE,
 241                         // Whether the task can be paused (not yet implemented)
 242                         'task_pauseable'      => TRUE,
 243                         // Timestamp of registration
 244                         'task_registered'     => $this->getMilliTime(),
 245                         // Last activity timestamp
 246                         'task_last_activity'  => 0,
 247                         // Total runs of this task
 248                         'task_total_runs'     => 0,
 249                         // Task instance itself
 250                         'task_instance'       => $taskInstance,
 251                         // Startup delay in milliseconds
 252                         'task_startup_delay'  => $startupDelay,
 253                         // Interval time (delay) in milliseconds before this task is executed again
 254                         'task_interval_delay' => $intervalDelay,
 255                         // How often should this task run?
 256                         'task_max_runs'       => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
 257                 );
 258
 259                 // Add the entry
 260                 $this->getListInstance()->addEntry('tasks', $taskEntry);
 261
 262                 // Debug message
 263                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task registered: taskName=' . $taskName .
 264                         ' (taskInstance=' . $taskInstance->__toString() . ')' .
 265                         ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
 266                         ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
 267                         ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
 268                 );
 269         }
 270
 271         /**
 272          * Checks whether tasks are left including idle task
 273          *
 274          * @return      $tasksLeft      Whether there are tasks left to handle
 275          */
 276         public function hasTasksLeft () {
 277                 // Do we have tasks there?
 278                 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
 279
 280                 // Return result
 281                 return $tasksLeft;
 282         }
 283
 284         /**
 285          * Handles all tasks by checking if they should startup or if it is their
 286          * turn to run. You should use this method in a while() loop in conjuntion
 287          * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
 288          * which will attempt to remove all tasks from the task handler.
 289          *
 290          * @return      void
 291          */
 292         public function handleTasks () {
 293                 // Should we rewind?
 294                 if (!$this->getListInstance()->getIterator()->valid()) {
 295                         // Rewind to the beginning for next loop
 296                         $this->getListInstance()->getIterator()->rewind();
 297                 } // END - if
 298
 299                 // Try to execute the task
 300                 $this->executeCurrentTask();
 301
 302                 // Go to next entry
 303                 $this->getListInstance()->getIterator()->next();
 304         }
 305
 306         /**
 307          * Shuts down all tasks and the task handler itself. This method should be
 308          * called from a corresponding filter class.
 309          *
 310          * @return      void
 311          */
 312         public function doShutdown () {
 313                 // Always rewind to the beginning for next loop
 314                 $this->getListInstance()->getIterator()->rewind();
 315
 316                 // Debug message
 317                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
 318
 319                 // Remember all tasks that has been shutdown for removal
 320                 $tasks = array();
 321
 322                 // Instance a visitor
 323                 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
 324
 325                 // Shutdown all tasks in once go
 326                 while ($this->getListInstance()->getIterator()->valid()) {
 327                         // Get current entry
 328                         $currentTask = $this->getListInstance()->getIterator()->current();
 329
 330                         // Output debug message
 331                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
 332
 333                         // Shutdown the task
 334                         $currentTask['task_instance']->accept($this->getVisitorInstance());
 335
 336                         // Remember this task
 337                         array_push($tasks, $currentTask);
 338
 339                         // Advance to next one
 340                         $this->getListInstance()->getIterator()->next();
 341                 } // END - while
 342
 343                 // Debug message
 344                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutdown of all tasks completed.');
 345
 346                 // Remove all tasks
 347                 foreach ($tasks as $entry) {
 348                         $this->unregisterTask($entry);
 349                 } // END - foreach
 350         }
 351
 352 }