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