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\Bootstrap\FrameworkBootstrap;
   7 use Org\Mxchange\CoreFramework\Factory\Object\ObjectFactory;
   8 use Org\Mxchange\CoreFramework\Handler\BaseHandler;
   9 use Org\Mxchange\CoreFramework\Registry\Registerable;
  10 use Org\Mxchange\CoreFramework\Task\Taskable;
  11 use Org\Mxchange\CoreFramework\Traits\Iterator\IteratorTrait;
  12 use Org\Mxchange\CoreFramework\Traits\Lists\ListableTrait;
  13 use Org\Mxchange\CoreFramework\Traits\Visitor\VisitorTrait;
  14 use Org\Mxchange\CoreFramework\Visitor\Visitable;
  15
  16 // Import SPL stuff
  17 use \InvalidArgumentException;
  18 use \UnexpectedValueException;
  19
  20 /**
  21  * A Task handler
  22  *
  23  * @author              Roland Haeder <webmaster@shipsimu.org>
  24  * @version             0.0.0
  25  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2022 Core Developer Team
  26  * @license             GNU GPL 3.0 or any newer version
  27  * @link                http://www.shipsimu.org
  28  *
  29  * This program is free software: you can redistribute it and/or modify
  30  * it under the terms of the GNU General Public License as published by
  31  * the Free Software Foundation, either version 3 of the License, or
  32  * (at your option) any later version.
  33  *
  34  * This program is distributed in the hope that it will be useful,
  35  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  36  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  37  * GNU General Public License for more details.
  38  *
  39  * You should have received a copy of the GNU General Public License
  40  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  41  */
  42 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
  43         // Load traits
  44         use IteratorTrait;
  45         use ListableTrait;
  46         use VisitorTrait;
  47
  48         // Exception constants
  49         const EXCEPTION_TASK_IS_INVALID = 0xb00;
  50
  51         /**
  52          * Protected constructor
  53          *
  54          * @return      void
  55          */
  56         private function __construct () {
  57                 // Call parent constructor
  58                 parent::__construct(__CLASS__);
  59
  60                 // Set handler name
  61                 $this->setHandlerName('task');
  62         }
  63
  64         /**
  65          * Creates an instance of this class
  66          *
  67          * @return      $handlerInstance        An instance of a HandleableTask class
  68          */
  69         public static final function createTaskHandler () {
  70                 // Get new instance
  71                 $handlerInstance = new TaskHandler();
  72
  73                 // Output debug message
  74                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Initializing task handler.');
  75
  76                 // Init the task list
  77                 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
  78
  79                 // Get default instance
  80                 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
  81
  82                 // Init visitor instance for faster loop
  83                 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
  84
  85                 // Register the first (and generic) idle-loop task
  86                 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
  87                 $handlerInstance->registerTask('idle_loop', $taskInstance);
  88
  89                 // Output debug message
  90                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task handler initialized.');
  91
  92                 // Return the prepared instance
  93                 return $handlerInstance;
  94         }
  95
  96         /**
  97          * Tries to execute the given task. If as task should not be started (yet)
  98          * or the interval time (see task_interval_delay) is not yet reached the
  99          * task is quietly skipped.
 100          *
 101          * @return      void
 102          * @throws      InvalidTaskException    If the current task is invalid
 103          */
 104         private function executeCurrentTask () {
 105                 // Update no task by default
 106                 $updateTask = false;
 107
 108                 // Is the current task valid?
 109                 if (!$this->getListInstance()->getIterator()->valid()) {
 110                         // Not valid!
 111                         throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
 112                 }
 113
 114                 // Get current task
 115                 $currentTask = $this->getListInstance()->getIterator()->current();
 116
 117                 // Is the task not yet started?
 118                 if ($currentTask['task_started'] === false) {
 119                         // Determine difference between current time and registration
 120                         $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
 121
 122                         // Should we start now?
 123                         if ($diff < $currentTask['task_startup_delay']) {
 124                                 // Skip this silently
 125                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' not started: diff=' . $diff . ',task_startup_delay=' . $currentTask['task_startup_delay']);
 126                                 return;
 127                         }
 128
 129                         // Launch the task and mark it as updated
 130                         $currentTask['task_started'] = true;
 131                         $updateTask = true;
 132
 133                         // Debug message
 134                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
 135                 }
 136
 137                 // Get time difference from interval delay
 138                 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
 139
 140                 // Is the interval delay reached?
 141                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' diff=' . $diff . ',task_interval_delay=' . $currentTask['task_interval_delay'] . ',task_max_runs=' . $currentTask['task_max_runs'] . ',task_total_runs=' . $currentTask['task_total_runs']);
 142                 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_max_runs'] > 0) && ($currentTask['task_total_runs'] == $currentTask['task_max_runs']))) {
 143                         // Should we update the task from startup?
 144                         if ($updateTask === true) {
 145                                 // Update the task before leaving
 146                                 $this->updateTask($currentTask);
 147                         }
 148
 149                         // Skip this silently
 150                         return;
 151                 }
 152
 153                 // Set last activity
 154                 $currentTask['task_last_activity'] = $this->getMilliTime();
 155
 156                 // Count this run
 157                 $currentTask['task_total_runs']++;
 158
 159                 // Update the task
 160                 $this->updateTask($currentTask);
 161
 162                 // And visit/run it
 163                 // @TODO Messurement can be added around this call
 164                 $currentTask['task_instance']->accept($this->getVisitorInstance());
 165         }
 166
 167         /**
 168          * Updates given task by updating the underlaying list
 169          *
 170          * @param       $taskEntry      An array with a task
 171          * @return      void
 172          */
 173         private function updateTask (array $taskEntry) {
 174                 // Get the key from current iteration
 175                 $key = $this->getListInstance()->getIterator()->key();
 176
 177                 // Get the hash from key
 178                 $hash = $this->getListInstance()->getHashByIndex($key);
 179
 180                 // Update the entry
 181                 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
 182         }
 183
 184         /**
 185          * Unregisters the given task
 186          *
 187          * @param       $taskData       Data of the task
 188          * @return      void
 189          */
 190         private function unregisterTask (array $taskData) {
 191                 // Debug output
 192                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
 193
 194                 // Remove the entry
 195                 $this->getListInstance()->removeEntry('tasks', $taskData);
 196
 197                 // Debug output
 198                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
 199          }
 200
 201         /**
 202          * Searches a task by given instance
 203          *
 204          * @param       $taskInstanc    An instanceof a Taskable class
 205          * @return      $taskName               Name of the task as used while registration
 206          */
 207         public function searchTask (Taskable $taskInstance) {
 208                 // Default is an empty (not found) task name
 209                 $taskName = '';
 210
 211                 // Get whole list
 212                 $taskList = $this->getListInstance()->getArrayFromList('tasks');
 213
 214                 // Search all instances
 215                 foreach ($taskList as $currentTask) {
 216                         // Does it match given task instance?
 217                         if ($currentTask['task_instance']->equals($taskInstance)) {
 218                                 // Found it
 219                                 $taskName = $currentTask['id'];
 220
 221                                 // Abort here
 222                                 break;
 223                         }
 224                 }
 225
 226                 // Return found name
 227                 return $taskName;
 228         }
 229
 230         /**
 231          * Registers a task with a task handler.
 232          *
 233          * @param       $taskName               A task name to register the task on
 234          * @param       $taskInstance   An instance of a Taskable class
 235          * @return      void
 236          * @throws      InvalidArgumentException        If a parameter is not valid
 237          * @throws      UnexpectedValueException        If an unexpected value has been configured
 238          */
 239         public function registerTask (string $taskName, Taskable $taskInstance) {
 240                 // Is the parameter valid
 241                 if (empty($taskName)) {
 242                         // Task name cannot be empty
 243                         throw new InvalidArgumentException('Parameter "taskName" is empty');
 244                 }
 245
 246                 // Get interval delay, startup delay and max runs
 247                 $intervalDelay = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_interval_delay');
 248                 $startupDelay = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_startup_delay');
 249                 $maxRuns = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('task_' . $taskName . '_max_runs');
 250
 251                 // If the task is 'idle_loop', a deplay of zero seconds is fine
 252                 if ($intervalDelay < 0) {
 253                         // Invalid configuration value
 254                         throw new UnexpectedValueException(sprintf('taskName=%s has intervalDelay=%d below zero', $taskName, $intervalDelay));
 255                 } elseif ($startupDelay < 0) {
 256                         // Invalid configuration value
 257                         throw new UnexpectedValueException(sprintf('taskName=%s has startupDelay=%d below zero', $taskName, $startupDelay));
 258                 } elseif ($maxRuns < 0) {
 259                         // Invalid configuration value
 260                         throw new UnexpectedValueException(sprintf('taskName=%s has maxRuns=%d below zero', $taskName, $maxRuns));
 261                 } elseif ($taskName != 'idle_loop' && $intervalDelay == 0) {
 262                         // Only idle_loop can have a zero interval delay
 263                         throw new UnexpectedValueException(sprintf('taskName=%s has zero interval delay which is only valid for "idle_loop" task', $taskName));
 264                 } elseif ($taskName != 'idle_loop' && $startupDelay == 0) {
 265                         // Only idle_loop can have a zero interval delay
 266                         throw new UnexpectedValueException(sprintf('taskName=%s has zero startup delay which is only valid for "idle_loop" task', $taskName));
 267                 }
 268
 269                 // Create the entry
 270                 $taskEntry = [
 271                         // Identifier for the generateHash() method
 272                         'id'                  => $taskName,
 273                         // Whether the task is started
 274                         'task_started'        => false,
 275                         // Whether the task is paused (not yet implemented)
 276                         'task_paused'         => false,
 277                         // Whether the task can be paused (not yet implemented)
 278                         'task_pauseable'      => true,
 279                         // Timestamp of registration
 280                         'task_registered'     => $this->getMilliTime(),
 281                         // Last activity timestamp
 282                         'task_last_activity'  => 0,
 283                         // Total runs of this task
 284                         'task_total_runs'     => 0,
 285                         // Task instance itself
 286                         'task_instance'       => $taskInstance,
 287                         // Startup delay in milliseconds
 288                         'task_startup_delay'  => $startupDelay,
 289                         // Interval time (delay) in milliseconds before this task is executed again
 290                         'task_interval_delay' => $intervalDelay,
 291                         // How often should this task run?
 292                         'task_max_runs'       => $maxRuns,
 293                 ];
 294
 295                 // Add the entry
 296                 $this->getListInstance()->addEntry('tasks', $taskEntry);
 297
 298                 // Debug message
 299                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Task registered: taskName=' . $taskName .
 300                         ' (taskInstance=' . $taskInstance->__toString() . ')' .
 301                         ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
 302                         ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
 303                         ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
 304                 );
 305         }
 306
 307         /**
 308          * Checks whether tasks are left including idle task
 309          *
 310          * @return      $tasksLeft      Whether there are tasks left to handle
 311          */
 312         public function hasTasksLeft () {
 313                 // Do we have tasks there?
 314                 $tasksLeft = ($this->getListInstance()->count() > 0);
 315
 316                 // Return result
 317                 return $tasksLeft;
 318         }
 319
 320         /**
 321          * Handles all tasks by checking if they should startup or if it is their
 322          * turn to run. You should use this method in a while() loop in conjuntion
 323          * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
 324          * which will attempt to remove all tasks from the task handler.
 325          *
 326          * @return      void
 327          */
 328         public function handleTasks () {
 329                 // Should we rewind?
 330                 if (!$this->getListInstance()->getIterator()->valid()) {
 331                         // Rewind to the beginning for next loop
 332                         $this->getListInstance()->getIterator()->rewind();
 333                 }
 334
 335                 // Try to execute the task
 336                 $this->executeCurrentTask();
 337
 338                 // Go to next entry
 339                 $this->getListInstance()->getIterator()->next();
 340         }
 341
 342         /**
 343          * Shuts down all tasks and the task handler itself. This method should be
 344          * called from a corresponding filter class.
 345          *
 346          * @return      void
 347          */
 348         public function doShutdown () {
 349                 // Always rewind to the beginning for next loop
 350                 $this->getListInstance()->getIterator()->rewind();
 351
 352                 // Debug message
 353                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
 354
 355                 // Remember all tasks that has been shutdown for removal
 356                 $tasks = [];
 357
 358                 // Instance a visitor
 359                 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
 360
 361                 // Shutdown all tasks in once go
 362                 while ($this->getListInstance()->getIterator()->valid()) {
 363                         // Get current entry
 364                         $currentTask = $this->getListInstance()->getIterator()->current();
 365
 366                         // Output debug message
 367                         self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
 368
 369                         // Shutdown the task
 370                         $currentTask['task_instance']->accept($this->getVisitorInstance());
 371
 372                         // Remember this task
 373                         array_push($tasks, $currentTask);
 374
 375                         // Advance to next one
 376                         $this->getListInstance()->getIterator()->next();
 377                 }
 378
 379                 // Debug message
 380                 self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('TASK-HANDLER: Shutdown of all tasks completed.');
 381
 382                 // Remove all tasks
 383                 foreach ($tasks as $entry) {
 384                         $this->unregisterTask($entry);
 385                 }
 386         }
 387
 388 }