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

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