runcmf/runtracy

<?php

namespace RunTracy\Helpers\Profiler;

/**
 * Singleton trait
 *
 * @author   Petr Knap <dev@petrknap.cz>
 * @since    2015-04-18
 * @category Patterns
 * @package  PetrKnap\Php\Singleton
 * @version  0.4
 * @license  https://github.com/petrknap/php-singleton/blob/master/LICENSE MIT
 */
trait SingletonTrait
{
    /**
     * @var self[]
     */
    private static $instances = [];

    /**
     * Returns instance, if instance does not exist then creates new one and returns it
     *
     * @return $this
     */
    public static function getInstance()
    {
        $self = get_called_class();
        if (!isset(self::$instances[$self])) {
            self::$instances[$self] = new $self;
        }
        return self::$instances[$self];
    }

    /**
     * @return bool true if has instance, otherwise false
     */
    public static function hasInstance()
    {
        $self = get_called_class();
        return isset(self::$instances[$self]);
    }
}