5 * @author Roland Haeder <webmaster@shipsimu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 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[' . __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[' . __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
105 // Launch the task and mark it as updated
106 $currentTask['task_started'] = TRUE;
110 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Task ' . $currentTask['id'] . ' started with startup_delay=' . $currentTask['task_startup_delay'] . 'ms');
113 // Get time difference from interval delay
114 $diff = ($this->getMilliTime() - $currentTask['task_last_activity']) * 1000;
116 // Is the interval delay reached?
117 if ((($diff < $currentTask['task_interval_delay']) && ($currentTask['task_max_runs'] == 0)) || (($currentTask['task_total_runs'] == $currentTask['task_max_runs']) && ($currentTask['task_max_runs'] > 0))) {
118 // Should we update the task from startup?
119 if ($updateTask === TRUE) {
120 // Update the task before leaving
121 $this->updateTask($currentTask);
124 // Skip this silently
129 $currentTask['task_last_activity'] = $this->getMilliTime();
132 $currentTask['task_total_runs']++;
135 $this->updateTask($currentTask);
138 // @TODO Messurement can be added around this call
139 $currentTask['task_instance']->accept($this->getVisitorInstance());
143 * Updates given task by updating the underlaying list
145 * @param $taskEntry An array with a task
148 private function updateTask (array $taskEntry) {
149 // Get the key from current iteration
150 $key = $this->getListInstance()->getIterator()->key();
152 // Get the hash from key
153 $hash = $this->getListInstance()->getHash($key);
156 $this->getListInstance()->updateCurrentEntryByHash($hash, $taskEntry);
160 * Unregisters the given task
162 * @param $taskData Data of the task
165 private function unregisterTask (array $taskData) {
167 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - START');
170 $this->getListInstance()->removeEntry('tasks', $taskData);
173 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Removing task ' . $taskData['id'] . ' from queue - FINISHED');
177 * Registers a task with a task handler.
179 * @param $taskName A task name to register the task on
180 * @param $taskInstance The instance we should register as a task
183 public function registerTask ($taskName, Visitable $taskInstance) {
186 // Identifier for the generateHash() method
188 // Whether the task is started
189 'task_started' => FALSE,
190 // Whether the task is paused (not yet implemented)
191 'task_paused' => FALSE,
192 // Whether the task can be paused (not yet implemented)
193 'task_pauseable' => TRUE,
194 // Timestamp of registration
195 'task_registered' => $this->getMilliTime(),
196 // Last activity timestamp
197 'task_last_activity' => 0,
198 // Total runs of this task
199 'task_total_runs' => 0,
200 // Task instance itself
201 'task_instance' => $taskInstance,
202 // Startup delay in milliseconds
203 'task_startup_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_startup_delay'),
204 // Interval time (delay) in milliseconds before this task is executed again
205 'task_interval_delay' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_interval_delay'),
206 // How often should this task run?
207 'task_max_runs' => $this->getConfigInstance()->getConfigEntry('task_' . $taskName . '_max_runs'),
211 $this->getListInstance()->addEntry('tasks', $taskEntry);
214 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Task registered: taskName=' . $taskName .
215 ' (taskInstance=' . $taskInstance->__toString() . ')' .
216 ', startupDelay=' . $taskEntry['task_startup_delay'] . 'ms' .
217 ', intervalDelay=' . $taskEntry['task_interval_delay'] . 'ms' .
218 ', maxRuns=' . $taskEntry['task_max_runs'] . ' ...'
223 * Checks whether tasks are left including idle task
225 * @return $tasksLeft Whether there are tasks left to handle
227 public function hasTasksLeft () {
228 // Do we have tasks there?
229 $tasksLeft = (($this->getListInstance() instanceof Listable) && ($this->getListInstance()->count() > 0));
236 * Handles all tasks by checking if they should startup or if it is their
237 * turn to run. You should use this method in a while() loop in conjuntion
238 * with hasTasksLeft() so you can e.g. shutdown by adding a ShutdownTask
239 * which will attempt to remove all tasks from the task handler.
243 public function handleTasks () {
245 if (!$this->getListInstance()->getIterator()->valid()) {
246 // Rewind to the beginning for next loop
247 $this->getListInstance()->getIterator()->rewind();
250 // Try to execute the task
251 $this->executeCurrentTask();
254 $this->getListInstance()->getIterator()->next();
258 * Shuts down all tasks and the task handler itself. This method should be
259 * called from a corresponding filter class.
263 public function doShutdown () {
264 // Always rewind to the beginning for next loop
265 $this->getListInstance()->getIterator()->rewind();
268 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Shutting down all ' . $this->getListInstance()->count() . ' tasks...');
270 // Remember all tasks that has been shutdown for removal
273 // Instance a visitor
274 $this->setVisitorInstance(ObjectFactory::createObjectByConfiguredName('shutdown_task_visitor_class'));
276 // Shutdown all tasks in once go
277 while ($this->getListInstance()->getIterator()->valid()) {
279 $currentTask = $this->getListInstance()->getIterator()->current();
281 // Output debug message
282 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Shutting down task ' . $currentTask['id'] . ' (taskInstance=' . $currentTask['task_instance']->__toString() . ') ...');
285 $currentTask['task_instance']->accept($this->getVisitorInstance());
287 // Remember this task
288 array_push($tasks, $currentTask);
290 // Advance to next one
291 $this->getListInstance()->getIterator()->next();
295 self::createDebugInstance(__CLASS__)->debugOutput('TASK-HANDLER[' . __LINE__ . ']: Shutdown of all tasks completed.');
298 foreach ($tasks as $entry) {
299 $this->unregisterTask($entry);