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