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

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Handler\Task;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Factory\ObjectFactory;
   7 use Org\Mxchange\CoreFramework\Handler\BaseHandler;
   8 use Org\Mxchange\CoreFramework\Lists\Listable;
   9 use Org\Mxchange\CoreFramework\Registry\Registerable;
  10 use Org\Mxchange\CoreFramework\Task\Taskable;
  11 use Org\Mxchange\CoreFramework\Visitor\Visitable;
  12
  13 /**
  14  * A Task handler
  15  *
  16  * @author              Roland Haeder <webmaster@shipsimu.org>
  17  * @version             0.0.0
  18  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2019 Core Developer Team
  19  * @license             GNU GPL 3.0 or any newer version
  20  * @link                http://www.shipsimu.org
  21  *
  22  * This program is free software: you can redistribute it and/or modify
  23  * it under the terms of the GNU General Public License as published by
  24  * the Free Software Foundation, either version 3 of the License, or
  25  * (at your option) any later version.
  26  *
  27  * This program is distributed in the hope that it will be useful,
  28  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  29  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  30  * GNU General Public License for more details.
  31  *
  32  * You should have received a copy of the GNU General Public License
  33  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  34  */
  35 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
  36         // Exception constants
  37         const EXCEPTION_TASK_IS_INVALID = 0xb00;
  38
  39         /**
  40          * Protected constructor
  41          *
  42          * @return      void
  43          */
  44         protected function __construct () {
  45                 // Call parent constructor
  46                 parent::__construct(__CLASS__);
  47
  48                 // Set handler name
  49                 $this->setHandlerName('task');
  50         }
  51
  52         /**
  53          * Creates an instance of this class
  54          *
  55          * @return      $handlerInstance        An instance of a HandleableTask class
  56          */
  57         public static final function createTaskHandler () {
  58                 // Get new instance
  59                 $handlerInstance = new TaskHandler();
  60
  61                 // Output debug message
  62                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Initializing task handler.');
  63
  64                 // Init the task list
  65                 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
  66
  67                 // Get default instance
  68                 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
  69
  70                 // Init visitor instance for faster loop
  71                 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
  72
  73                 // Register the first (and generic) idle-loop task
  74                 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
  75                 $handlerInstance->registerTask('idle_loop', $taskInstance);
  76
  77                 // Output debug message
  78                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task handler initialized.');
  79
  80                 // Return the prepared instance
  81                 return $handlerInstance;
  82         }
  83
  84         /**
  85          * Tries to execute the given task. If as task should not be started (yet)
  86          * or the interval time (see task_interval_delay) is not yet reached the
  87          * task is quietly skipped.
  88          *
  89          * @return      void
  90          * @throws      InvalidTaskException    If the current task is invalid
  91          */
  92         private function executeCurrentTask () {
  93                 // Update no task by default
  94                 $updateTask = false;
  95
  96                 // Is the current task valid?
  97                 if (!$this->getListInstance()->getIterator()->valid()) {
  98                         // Not valid!
  99                         throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
 100                 } // END - if
 101
 102                 // Get current task
 103                 $currentTask = $this->getListInstance()->getIterator()->current();
 104
 105                 // Is the task not yet started?
 106                 if ($currentTask['task_started'] === false) {
 107                         // Determine difference between current time and registration
 108                         $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
 109
 110                         // Should we start now?
 111                         if ($diff < $currentTask['task_startup_delay']) {
 112                                 // Skip this silently
 113                                 //* 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']);
 114                                 return;
 115                         } // END - if
 116
 117                         // Launch the task and mark it as updated
 118                         $currentTask['task_started'] = true;
 119                         $updateTask = true;
 120
 121                         // Debug message
 122                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
 123                 } // END - if
 124
 125                 // Get time difference from interval delay
 126                 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
 127
 128                 // Debug message
 129                 //* 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=' . $currentTask['task_total_runs']);
 130
 131                 // Is the interval delay reached?
 132                 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_max_runs'] > 0) && ($currentTask['task_total_runs'] == $currentTask['task_max_runs']))) {
 133                         // Should we update the task from startup?
 134                         if ($updateTask === true) {
 135                                 // Update the task before leaving
 136                                 $this->updateTask($currentTask);
 137                         } // END - if
 138
 139                         // Skip this silently
 140                         return;
 141                 } // END - if
 142
 143                 // Set last activity
 144                 $currentTask['task_last_activity'] = $this->getMilliTime();
 145
 146                 // Count this run
 147                 $currentTask['task_total_runs']++;
 148
 149                 // Update the task
 150                 $this->updateTask($currentTask);
 151
 152                 // And visit/run it
 153                 // @TODO Messurement can be added around this call
 154                 $currentTask['task_instance']->accept($this->getVisitorInstance());
 155         }
 156
 157         /**
 158          * Updates given task by updating the underlaying list
 159          *
 160          * @param       $taskEntry      An array with a task
 161          * @return      void
 162          */
 163         private function updateTask (array $taskEntry) {
 164                 // Get the key from current iteration
 165                 $key = $this->getListInstance()->getIterator()->key();
 166
 167                 // Get the hash from key
 168                 $hash = $this->getListInstance()->getHash($key);
 169
 170                 // Update the entry
 171                 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
 172         }
 173
 174         /**
 175          * Unregisters the given task
 176          *
 177          * @param       $taskData       Data of the task
 178          * @return      void
 179          */
 180         private function unregisterTask (array $taskData) {
 181                 // Debug output
 182                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
 183
 184                 // Remove the entry
 185                 $this->getListInstance()->removeEntry('tasks', $taskData);
 186
 187                 // Debug output
 188                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
 189          }
 190
 191         /**
 192          * Searches a task by given instance
 193          *
 194          * @param       $taskInstanc    An instanceof a Taskable class
 195          * @return      $taskName               Name of the task as used while registration
 196          */
 197         public function searchTask (Taskable $taskInstance) {
 198                 // Default is an empty (not found) task name
 199                 $taskName = '';
 200
 201                 // Get whole list
 202                 $taskList = $this->getListInstance()->getArrayFromList('tasks');
 203
 204                 // Search all instances
 205                 foreach ($taskList as $currentTask) {
 206                         // Does it match given task instance?
 207                         if ($currentTask['task_instance']->equals($taskInstance)) {
 208                                 // Found it
 209                                 $taskName = $currentTask['id'];
 210
 211                                 // Abort here
 212                                 break;
 213                         } // END - if
 214                 } // END - foreach
 215
 216                 // Return found name
 217                 return $taskName;
 218         }
 219
 220         /**
 221          * Registers a task with a task handler.
 222          *
 223          * @param       $taskName               A task name to register the task on
 224          * @param       $taskInstance   The instance that should be registered as a task
 225          * @return      void
 226          */
 227         public function registerTask ($taskName, Visitable $taskInstance) {
 228                 // Get interval delay
 229                 $intervalDelay = $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay');
 230                 $startupDelay  = $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay');
 231
 232                 // If the task is 'idle_loop', a deplay of zero seconds is fine
 233                 assert($intervalDelay >= 0);
 234                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($intervalDelay > 0)));
 235                 assert(($taskName === 'idle_loop') || (($taskName != 'idle_loop') && ($startupDelay > 0)));
 236
 237                 // Create the entry
 238                 $taskEntry = array(
 239                         // Identifier for the generateHash() method
 240                         'id'                  => $taskName,
 241                         // Whether the task is started
 242                         'task_started'        => false,
 243                         // Whether the task is paused (not yet implemented)
 244                         'task_paused'         => false,
 245                         // Whether the task can be paused (not yet implemented)
 246                         'task_pauseable'      => true,
 247                         // Timestamp of registration
 248                         'task_registered'     => $this->getMilliTime(),
 249                         // Last activity timestamp
 250                         'task_last_activity'  => 0,
 251                         // Total runs of this task
 252                         'task_total_runs'     => 0,
 253                         // Task instance itself
 254                         'task_instance'       => $taskInstance,
 255                         // Startup delay in milliseconds
 256                         'task_startup_delay'  => $startupDelay,
 257                         // Interval time (delay) in milliseconds before this task is executed again
 258                         'task_interval_delay' => $intervalDelay,
 259                         // How often should this task run?
 260                         'task_max_runs'       => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
 261                 );
 262
 263                 // Add the entry
 264                 $this->getListInstance()->addEntry('tasks', $taskEntry);
 265
 266                 // Debug message
 267                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task registered: taskName=' . $taskName .
 268                         ' (taskInstance=' . $taskInstance->__toString() . ')' .
 269                         ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
 270                         ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
 271                         ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
 272                 );
 273         }
 274
 275         /**
 276          * Checks whether tasks are left including idle task
 277          *
 278          * @return      $tasksLeft      Whether there are tasks left to handle
 279          */
 280         public function hasTasksLeft () {
 281                 // Do we have tasks there?
 282                 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
 283
 284                 // Return result
 285                 return $tasksLeft;
 286         }
 287
 288         /**
 289          * Handles all tasks by checking if they should startup or if it is their
 290          * turn to run. You should use this method in a while() loop in conjuntion
 291          * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
 292          * which will attempt to remove all tasks from the task handler.
 293          *
 294          * @return      void
 295          */
 296         public function handleTasks () {
 297                 // Should we rewind?
 298                 if (!$this->getListInstance()->getIterator()->valid()) {
 299                         // Rewind to the beginning for next loop
 300                         $this->getListInstance()->getIterator()->rewind();
 301                 } // END - if
 302
 303                 // Try to execute the task
 304                 $this->executeCurrentTask();
 305
 306                 // Go to next entry
 307                 $this->getListInstance()->getIterator()->next();
 308         }
 309
 310         /**
 311          * Shuts down all tasks and the task handler itself. This method should be
 312          * called from a corresponding filter class.
 313          *
 314          * @return      void
 315          */
 316         public function doShutdown () {
 317                 // Always rewind to the beginning for next loop
 318                 $this->getListInstance()->getIterator()->rewind();
 319
 320                 // Debug message
 321                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
 322
 323                 // Remember all tasks that has been shutdown for removal
 324                 $tasks = array();
 325
 326                 // Instance a visitor
 327                 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
 328
 329                 // Shutdown all tasks in once go
 330                 while ($this->getListInstance()->getIterator()->valid()) {
 331                         // Get current entry
 332                         $currentTask = $this->getListInstance()->getIterator()->current();
 333
 334                         // Output debug message
 335                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
 336
 337                         // Shutdown the task
 338                         $currentTask['task_instance']->accept($this->getVisitorInstance());
 339
 340                         // Remember this task
 341                         array_push($tasks, $currentTask);
 342
 343                         // Advance to next one
 344                         $this->getListInstance()->getIterator()->next();
 345                 } // END - while
 346
 347                 // Debug message
 348                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutdown of all tasks completed.');
 349
 350                 // Remove all tasks
 351                 foreach ($tasks as $entry) {
 352                         $this->unregisterTask($entry);
 353                 } // END - foreach
 354         }
 355
 356 }