5 * @author Roland Haeder <webmaster@shipsimu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Hub Developer Team
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.shipsimu.org
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 class TaskHandler extends BaseHandler implements Registerable, HandleableTask {
25 // Exception constants
26 const EXCEPTION_TASK_IS_INVALID = 0xb00;
29 * Protected constructor
33 protected function __construct () {
34 // Call parent constructor
35 parent::__construct(__CLASS__);
38 $this->setHandlerName('task');
42 * Creates an instance of this class
44 * @return $handlerInstance An instance of a HandleableTask class
46 public static final function createTaskHandler () {
48 $handlerInstance = new TaskHandler();
50 // Output debug message
51 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Initializing task handler.');
54 $handlerInstance->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
56 // Get default instance
57 $handlerInstance->setIteratorInstance($handlerInstance->getListInstance()->getIterator());
59 // Init visitor instance for faster loop
60 $handlerInstance->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('active_task_visitor_class'));
62 // Register the first (and generic) idle-loop task
63 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
64 $handlerInstance->registerTask('idle_loop', $taskInstance);
66 // Output debug message
67 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task handler initialized.');
69 // Return the prepared instance
70 return $handlerInstance;
74 * Tries to execute the given task. If as task should not be started (yet)
75 * or the interval time (see task_interval_delay) is not yet reached the
76 * task is quietly skipped.
79 * @throws InvalidTaskException If the current task is invalid
81 private function executeCurrentTask () {
82 // Update no task by default
85 // Is the current task valid?
86 if (!$this->getListInstance()->getIterator()->valid()) {
88 throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
92 $currentTask = $this->getListInstance()->getIterator()->current();
94 // Is the task not yet started?
95 if ($currentTask['task_started'] === FALSE) {
96 // Determine difference between current time and registration
97 $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
99 // Should we start now?
100 if ($diff < $currentTask['task_startup_delay']) {
101 // Skip this silently
102 //* 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 // Launch the task and mark it as updated
107 $currentTask['task_started'] = TRUE;
111 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
114 // Get time difference from interval delay
115 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
117 // Is the interval delay reached?
118 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_total_runs'] == $currentTask['task_max_runs']) && ($currentTask['task_max_runs'] > 0))) {
119 // Should we update the task from startup?
120 if ($updateTask === TRUE) {
121 // Update the task before leaving
122 $this->updateTask($currentTask);
125 // Skip this silently
130 $currentTask['task_last_activity'] = $this->getMilliTime();
133 $currentTask['task_total_runs']++;
136 $this->updateTask($currentTask);
139 // @TODO Messurement can be added around this call
140 $currentTask['task_instance']->accept($this->getVisitorInstance());
144 * Updates given task by updating the underlaying list
146 * @param $taskEntry An array with a task
149 private function updateTask (array $taskEntry) {
150 // Get the key from current iteration
151 $key = $this->getListInstance()->getIterator()->key();
153 // Get the hash from key
154 $hash = $this->getListInstance()->getHash($key);
157 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
161 * Unregisters the given task
163 * @param $taskData Data of the task
166 private function unregisterTask (array $taskData) {
168 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - CALLED!');
171 $this->getListInstance()->removeEntry('tasks', $taskData);
174 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - EXIT!');
178 * Searches a task by given instance
180 * @param $taskInstanc An instanceof a Taskable class
181 * @return $taskName Name of the task as used while registration
183 public function searchTask (Taskable $taskInstance) {
184 // Default is an empty (not found) task name
188 $taskList = $this->getListInstance()->getArrayFromList('tasks');
190 // Search all instances
191 foreach ($taskList as $currentTask) {
192 // Does it match given task instance?
193 if ($currentTask['task_instance']->equals($taskInstance)) {
195 $taskName = $currentTask['id'];
207 * Registers a task with a task handler.
209 * @param $taskName A task name to register the task on
210 * @param $taskInstance The instance we should register as a task
213 public function registerTask ($taskName, Visitable $taskInstance) {
216 // Identifier for the generateHash() method
218 // Whether the task is started
219 'task_started' => FALSE,
220 // Whether the task is paused (not yet implemented)
221 'task_paused' => FALSE,
222 // Whether the task can be paused (not yet implemented)
223 'task_pauseable' => TRUE,
224 // Timestamp of registration
225 'task_registered' => $this->getMilliTime(),
226 // Last activity timestamp
227 'task_last_activity' => 0,
228 // Total runs of this task
229 'task_total_runs' => 0,
230 // Task instance itself
231 'task_instance' => $taskInstance,
232 // Startup delay in milliseconds
233 'task_startup_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay'),
234 // Interval time (delay) in milliseconds before this task is executed again
235 'task_interval_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay'),
236 // How often should this task run?
237 'task_max_runs' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
241 $this->getListInstance()->addEntry('tasks', $taskEntry);
244 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Task registered: taskName=' . $taskName .
245 ' (taskInstance=' . $taskInstance->__toString() . ')' .
246 ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
247 ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
248 ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
253 * Checks whether tasks are left including idle task
255 * @return $tasksLeft Whether there are tasks left to handle
257 public function hasTasksLeft () {
258 // Do we have tasks there?
259 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
266 * Handles all tasks by checking if they should startup or if it is their
267 * turn to run. You should use this method in a while() loop in conjuntion
268 * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
269 * which will attempt to remove all tasks from the task handler.
273 public function handleTasks () {
275 if (!$this->getListInstance()->getIterator()->valid()) {
276 // Rewind to the beginning for next loop
277 $this->getListInstance()->getIterator()->rewind();
280 // Try to execute the task
281 $this->executeCurrentTask();
284 $this->getListInstance()->getIterator()->next();
288 * Shuts down all tasks and the task handler itself. This method should be
289 * called from a corresponding filter class.
293 public function doShutdown () {
294 // Always rewind to the beginning for next loop
295 $this->getListInstance()->getIterator()->rewind();
298 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
300 // Remember all tasks that has been shutdown for removal
303 // Instance a visitor
304 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
306 // Shutdown all tasks in once go
307 while ($this->getListInstance()->getIterator()->valid()) {
309 $currentTask = $this->getListInstance()->getIterator()->current();
311 // Output debug message
312 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
315 $currentTask['task_instance']->accept($this->getVisitorInstance());
317 // Remember this task
318 array_push($tasks, $currentTask);
320 // Advance to next one
321 $this->getListInstance()->getIterator()->next();
325 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Shutdown of all tasks completed.');
328 foreach ($tasks as $entry) {
329 $this->unregisterTask($entry);