5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009, 2010 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->setListInstance(ObjectFactory::createObjectByConfiguredName('task_list_class'));
45 // Get default instance
46 $this->setIteratorInstance($this->getListInstance()->getIterator());
48 // Init visitor instance for faster loop
49 $this->visitorInstance = ObjectFactory::createObjectByConfiguredName('active_task_visitor_class');
53 * Creates an instance of this class
55 * @return $handlerInstance An instance of a HandleableTask class
57 public final static function createTaskHandler () {
59 $handlerInstance = new TaskHandler();
61 // Output debug message
62 $handlerInstance->debugOutput('TASK-HANDLER: Task handler initialized.');
64 // Return the prepared instance
65 return $handlerInstance;
69 * Tries to execute the given task. If as task should not be started (yet)
70 * or the interval time (see task_interval_delay) is not yet reached the
71 * task is quietly skipped.
74 * @throws InvalidTaskException If the current task is invalid
76 private function executeCurrentTask () {
77 // Update no task by default
80 // Is the current task valid?
81 if (!$this->getIteratorInstance()->valid()) {
83 throw new InvalidTaskException($this, self::EXCEPTION_TASK_IS_INVALID);
87 $currentTask = $this->getIteratorInstance()->current();
89 // Is the task not yet started?
90 if ($currentTask['task_started'] === false) {
91 // Determine difference between current time and registration
92 $diff = ($this->getMilliTime() - $currentTask['task_registered']) * 1000;
94 // Should we start now?
95 if ($diff < $currentTask['task_startup_delay']) {
100 // Launch the task and mark it as updated
101 $currentTask['task_started'] = true;
105 $this->debugOutput('TASK-HANDLER: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
108 // Get time difference from interval delay
109 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
111 // Is the interval delay reached?
112 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_total_runs'] == $currentTask['task_max_runs']) && ($currentTask['task_max_runs'] > 0))) {
113 // Should we update the task from startup?
114 if ($updateTask === true) {
115 // Update the task before leaving
116 $this->updateTask($currentTask);
119 // Skip this silently
124 $currentTask['task_last_activity'] = $this->getMilliTime();
127 $currentTask['task_total_runs']++;
130 $this->updateTask($currentTask);
133 // @TODO Messurement can be added around this call
134 $currentTask['task_instance']->accept($this->visitorInstance);
138 * Updates given task by updating the underlaying list
140 * @param $taskEntry An array with a task
143 private function updateTask (array $taskEntry) {
144 // Get the key from current iteration
145 $key = $this->getIteratorInstance()->key();
147 // Get the hash from key
148 $hash = $this->getListInstance()->getHash($key);
151 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
155 * Unregisters the given task
157 * @param $taskData Data of the task
160 private function unregisterTask (array $taskData) {
162 $this->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - START');
165 $this->getListInstance()->removeEntry('tasks', $taskData);
168 $this->debugOutput('TASK-HANDLER: Removing task ' . $taskData['id'] . ' from queue - FINISHED');
172 * Registers a task with a task handler.
174 * @param $taskName A task name to register the task on
175 * @param $taskInstance The instance we should register as a task
178 public function registerTask ($taskName, Visitable $taskInstance) {
181 // Identifier for the generateHash() method
183 // Wether the task is started
184 'task_started' => false,
185 // Wether the task is paused (not yet implemented)
186 'task_paused' => false,
187 // Wether the task can be paused (not yet implemented)
188 'task_pauseable' => true,
189 // Timestamp of registration
190 'task_registered' => $this->getMilliTime(),
191 // Last activity timestamp
192 'task_last_activity' => 0,
193 // Total runs of this task
194 'task_total_runs' => 0,
195 // Task instance itself
196 'task_instance' => $taskInstance,
197 // Startup delay in milliseconds
198 'task_startup_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay'),
199 // Interval time (delay) in milliseconds before this task is executed again
200 'task_interval_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay'),
201 // How often should this task run?
202 'task_max_runs' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
206 $this->getListInstance()->addEntry('tasks', $taskEntry);
209 $this->debugOutput('TASK-HANDLER: Task ' . $taskName .
210 ' (taskInstance=' . $taskInstance->__toString() . ')' .
211 ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
212 ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
213 ', maxRuns=' . $taskEntry['task_max_runs'] . ' times registered.'
218 * Checks wether tasks are left including idle task
220 * @return $tasksLeft Wether there are tasks left to handle
222 public function hasTasksLeft () {
223 // Do we have tasks there?
224 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
231 * Handles all tasks by checking if they should startup or if it is their
232 * turn to run. You should use this method in a while() loop in conjuntion
233 * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
234 * which will attempt to remove all tasks from the task handler.
238 public function handleTasks () {
240 if (!$this->getIteratorInstance()->valid()) {
241 // Rewind to the beginning for next loop
242 $this->getIteratorInstance()->rewind();
245 // Try to execute the task
246 $this->executeCurrentTask();
249 $this->getIteratorInstance()->next();
253 * Shuts down all tasks and the task handler itself. This method should be
254 * called from a corresponding filter class.
258 public function doShutdown () {
260 if (!$this->getIteratorInstance()->valid()) {
261 // Rewind to the beginning for next loop
262 $this->getIteratorInstance()->rewind();
266 $this->debugOutput('TASK-HANDLER: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
268 // Remember all tasks that has been shutdown for removal
271 // Instance a visitor
272 $this->visitorInstance = ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class');
274 // Shutdown all tasks in once go
275 while ($this->getIteratorInstance()->valid()) {
277 $current = $this->getIteratorInstance()->current();
279 // Output debug message
280 $this->debugOutput('TASK-HANDLER: Shutting down task ' . $current['id'] . ' (taskInstance=' . $current['task_instance']->__toString() . ') ...');
283 $current['task_instance']->accept($this->visitorInstance);
285 // Remember this task
288 // Advance to next one
289 $this->getIteratorInstance()->next();
294 $this->debugOutput('TASK-HANDLER: Shutdown of all tasks completed.');
297 foreach ($tasks as $entry) {
298 $this->unregisterTask($entry);