5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2011 Hub Developer Team
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.ship-simu.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 * Visitor instance for all tasks while they are active
31 private $visitorInstance = NULL;
34 * Protected constructor
38 protected function __construct () {
39 // Call parent constructor
40 parent::__construct(__CLASS__);
43 $this->setHandlerName('task');
46 $this->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
48 // Get default instance
49 $this->setIteratorInstance($this->getListInstance()->getIterator());
51 // Init visitor instance for faster loop
52 $this->visitorInstance = ObjectFactory::createObjectByConfiguredName('active_task_visitor_class');
56 * Creates an instance of this class
58 * @return $handlerInstance An instance of a HandleableTask class
60 public static final function createTaskHandler () {
62 $handlerInstance = new TaskHandler();
64 // Output debug message
65 $handlerInstance->debugOutput('TASK-HANDLER: Task handler initialized.');
67 // Register the first (and generic) idle-loop task
68 $taskInstance = ObjectFactory::createObjectByConfiguredName('idle_task_class');
69 $handlerInstance->registerTask('idle_loop', $taskInstance);
71 // Return the prepared instance
72 return $handlerInstance;
76 * Tries to execute the given task. If as task should not be started (yet)
77 * or the interval time (see task_interval_delay) is not yet reached the
78 * task is quietly skipped.
81 * @throws InvalidTaskException If the current task is invalid
83 private function executeCurrentTask () {
84 // Update no task by default
87 // Is the current task valid?
88 if (!$this->getIteratorInstance()->valid()) {
90 throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
94 $currentTask = $this->getIteratorInstance()->current();
96 // Is the task not yet started?
97 if ($currentTask['task_started'] === false) {
98 // Determine difference between current time and registration
99 $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
101 // Should we start now?
102 if ($diff < $currentTask['task_startup_delay']) {
103 // Skip this silently
107 // Launch the task and mark it as updated
108 $currentTask['task_started'] = true;
112 $this->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
115 // Get time difference from interval delay
116 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
118 // Is the interval delay reached?
119 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_total_runs'] == $currentTask['task_max_runs']) && ($currentTask['task_max_runs'] > 0))) {
120 // Should we update the task from startup?
121 if ($updateTask === true) {
122 // Update the task before leaving
123 $this->updateTask($currentTask);
126 // Skip this silently
131 $currentTask['task_last_activity'] = $this->getMilliTime();
134 $currentTask['task_total_runs']++;
137 $this->updateTask($currentTask);
140 // @TODO Messurement can be added around this call
141 $currentTask['task_instance']->accept($this->visitorInstance);
145 * Updates given task by updating the underlaying list
147 * @param $taskEntry An array with a task
150 private function updateTask (array $taskEntry) {
151 // Get the key from current iteration
152 $key = $this->getIteratorInstance()->key();
154 // Get the hash from key
155 $hash = $this->getListInstance()->getHash($key);
158 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
162 * Unregisters the given task
164 * @param $taskData Data of the task
167 private function unregisterTask (array $taskData) {
169 $this->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - START');
172 $this->getListInstance()->removeEntry('tasks', $taskData);
175 $this->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - FINISHED');
179 * Registers a task with a task handler.
181 * @param $taskName A task name to register the task on
182 * @param $taskInstance The instance we should register as a task
185 public function registerTask ($taskName, Visitable $taskInstance) {
188 // Identifier for the generateHash() method
190 // Wether the task is started
191 'task_started' => false,
192 // Wether the task is paused (not yet implemented)
193 'task_paused' => false,
194 // Wether the task can be paused (not yet implemented)
195 'task_pauseable' => true,
196 // Timestamp of registration
197 'task_registered' => $this->getMilliTime(),
198 // Last activity timestamp
199 'task_last_activity' => 0,
200 // Total runs of this task
201 'task_total_runs' => 0,
202 // Task instance itself
203 'task_instance' => $taskInstance,
204 // Startup delay in milliseconds
205 'task_startup_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay'),
206 // Interval time (delay) in milliseconds before this task is executed again
207 'task_interval_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay'),
208 // How often should this task run?
209 'task_max_runs' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
213 $this->getListInstance()->addEntry('tasks', $taskEntry);
216 $this->debugOutput('TASK-HANDLER: Task registered: taskName=' . $taskName .
217 ' (taskInstance=' . $taskInstance->__toString() . ')' .
218 ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
219 ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
220 ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
225 * Checks wether tasks are left including idle task
227 * @return $tasksLeft Wether there are tasks left to handle
229 public function hasTasksLeft () {
230 // Do we have tasks there?
231 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
238 * Handles all tasks by checking if they should startup or if it is their
239 * turn to run. You should use this method in a while() loop in conjuntion
240 * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
241 * which will attempt to remove all tasks from the task handler.
245 public function handleTasks () {
247 if (!$this->getIteratorInstance()->valid()) {
248 // Rewind to the beginning for next loop
249 $this->getIteratorInstance()->rewind();
252 // Try to execute the task
253 $this->executeCurrentTask();
256 $this->getIteratorInstance()->next();
260 * Shuts down all tasks and the task handler itself. This method should be
261 * called from a corresponding filter class.
265 public function doShutdown () {
266 // Always rewind to the beginning for next loop
267 $this->getIteratorInstance()->rewind();
270 $this->debugOutput('TASK-HANDLER: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
272 // Remember all tasks that has been shutdown for removal
275 // Instance a visitor
276 $this->visitorInstance = ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class');
278 // Shutdown all tasks in once go
279 while ($this->getIteratorInstance()->valid()) {
281 $currentTask = $this->getIteratorInstance()->current();
283 // Output debug message
284 $this->debugOutput('TASK-HANDLER: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
287 $currentTask['task_instance']->accept($this->visitorInstance);
289 // Remember this task
290 $tasks[] = $currentTask;
292 // Advance to next one
293 $this->getIteratorInstance()->next();
297 $this->debugOutput('TASK-HANDLER: Shutdown of all tasks completed.');
300 foreach ($tasks as $entry) {
301 $this->unregisterTask($entry);