PocketMine-MP/src/PocketMine/scheduler/ServerScheduler.php

<?php

/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team

 *
 *
*/

namespace PocketMine\Scheduler;

use PocketMine\Plugin\Plugin;

class ServerScheduler{

	/**
	 * @var \SplPriorityQueue<Task>
	 */
	protected $queue;

	/**
	 * @var TaskHandler[]
	 */
	protected $tasks = array();

	/**
	 * @var int
	 */
	private $ids = 1;

	/**
	 * @var int
	 */
	protected $currentTick = 0;

	public function __construct(){
		$this->queue = new \SplPriorityQueue();
	}

	/**
	 * @param Task $task
	 *
	 * @return null|TaskHandler
	 */
	public function scheduleTask(Task $task){
		return $this->addTask($task, -1, -1);
	}

	/**
	 * @param Task $task
	 * @param int  $delay
	 *
	 * @return null|TaskHandler
	 */
	public function scheduleDelayedTask(Task $task, $delay){
		return $this->addTask($task, (int) $delay, -1);
	}

	/**
	 * @param Task $task
	 * @param int  $period
	 *
	 * @return null|TaskHandler
	 */
	public function scheduleRepeatingTask(Task $task, $period){
		return $this->addTask($task, -1, (int) $period);
	}

	/**
	 * @param Task $task
	 * @param int  $delay
	 * @param int  $period
	 *
	 * @return null|TaskHandler
	 */
	public function scheduleDelayedRepeatingTask(Task $task, $delay, $period){
		return $this->addTask($task, (int) $delay, (int) $period);
	}

	/**
	 * @param int $taskId
	 */
	public function cancelTask($taskId){
		if(isset($this->tasks[$taskId])){
			$this->tasks[$taskId]->cancel();
			unset($this->tasks[$taskId]);
		}
	}

	/**
	 * @param Plugin $plugin
	 */
	public function cancelTasks(Plugin $plugin){
		foreach($this->tasks as $taskId => $task){
			if($task->getTask() instanceof PluginTask){
				$task->cancel();
				unset($this->tasks[$taskId]);
			}
		}
	}

	public function cancelAllTasks(){
		foreach($this->tasks as $task){
			$task->cancel();
		}
		$this->tasks = array();
	}

	/**
	 * @param int $taskId
	 *
	 * @return bool
	 */
	public function isQueued($taskId){
		return isset($this->tasks[$taskId]);
	}

	private function addTask(Task $task, $delay, $period){
		if($task instanceof PluginTask and !$task->getOwner()->isEnabled()){
			trigger_error("Plugin attempted to register a task while disabled", E_USER_WARNING);
			return null;
		}

		if($delay <= 0){
			$delay = -1;
		}

		if($period === 1){
			$period = 1;
		}elseif($period < -1){
			$period = -1;
		}

		return $this->handle(new TaskHandler($task, $this->nextId(), $delay, $period));
	}

	private function handle(TaskHandler $handler){
		if($handler->isDelayed()){
			$nextRun = $this->currentTick + $handler->getDelay();
		}else{
			$nextRun = $this->currentTick;
		}

		$handler->setNextRun($nextRun);
		$this->tasks[$handler->getTaskId()] = $handler;
		$this->queue->insert($handler, $nextRun);

		return $handler;
	}

	/**
	 * @param int $currentTick
	 */
	public function mainThreadHeartbeat($currentTick){
		$this->currentTick = $currentTick;

		while($this->isReady($this->currentTick)){
			$task = $this->queue->extract();
			if($task->isCancelled()){
				unset($this->tasks[$task->getTaskId()]);
				continue;
			}else{
				$task->run();
			}
			if($task->isRepeating()){
				$task->setNextRun($this->currentTick + $task->getPeriod());
				$this->queue->insert($task, $this->currentTick + $task->getPeriod());
			}else{
				$task->remove();
				unset($this->tasks[$task->getTaskId()]);
			}
		}
	}

	private function isReady($currentTicks){
		return count($this->tasks) > 0 and $this->queue->current()->getNextRun() <= $currentTicks;
	}

	/**
	 * @return int
	 */
	private function nextId(){
		return $this->ids++;
	}

}