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