rugleb/phpgpss

Modeling of control systems

dev-master 2018-10-13 20:39 UTC

Requires

• php: ^7.2
• tightenco/collect: ^5.6

MIT

• Gleb K.

• modeling
• rugleb
• gpss
• simulation
• imitation

README

phpGPSS - a library written in PHP, is an analog of the GPSS modeling language. Using this library, you can easily simulate and analyze your system, find out how effective your processes are.

For example, create a traffic simulator.

First of all, we define the transact - Car:

use GPSS\Foundation\Transact\Transact;

/**
 * The Car class.
 */
class Car extends Transact
{
    //
}

Next, define a Generator that will generate new Transacts (in our case Car) at a certain point in time:

use GPSS\Foundation\Generator;

/**
 * The CarGenerator class.
 *
 * @package App
 */
class CarGenerator extends Generator
{

    /**
     * Get delay time.
     *
     * @return int
     */
    public function getDelayTime(): int
    {
        return rand(5, 9) * 10;
    }

    /**
     * Get transact class name.
     *
     * @return string
     */
    public function getTransactName(): string
    {
        return Car::class;
    }

}

Next, define the Service that will handle our Car transacts created by the CarGenerator.
Here we added a HasModel, which will allow us to use the Queue to enter the device: RoadService.
The most important punctuation is the definition of the handle method, which contains the logic of transaction processing by the service.
Also, we set the transaction processing time in the device, for which the method getDelayTime.

use GPSS\Foundation\Service\Service;
use GPSS\Foundation\Service\HasQueue;
use GPSS\Foundation\Transact\Transact;

/**
 * The RoadService class.
 */
class RoadService extends Service
{
    use HasQueue;

    /**
     * Handle input transact.
     *
     * @param Transact $transact
     * @return mixed
     */
    public function handle(Transact &$transact)
    {
        if ($this->isFree()) {
            return $this->seize($transact);
        }

        if ($this->isProcessing($transact)) {

            if ($this->canRelease($transact)) {
                return $this->release()->terminate($transact);
            }

            return $this;
        }
        
        return $this->queue($transact);
    }

    /**
     * Get delay time.
     *
     * @return int
     */
    public function getDelayTime(): int
    {
        return rand(2, 8) * 10;
    }

}

Now, everything is ready. It remains to create an instance of the Model and run the simulation.
Pay attention to the config that the Model accepts.
This config connects services, transactions and generators.

require_once __DIR__ . '/vendor/autoload.php';

use App\Car;
use App\RoadService;
use App\CarGenerator;
use GPSS\Foundation\Model;

$config = [
    'map' => [
        Car::class => RoadService::class,
    ],
    'services' => [
        RoadService::class,
    ],
    'generators' => [
        CarGenerator::class,
        CarGenerator::class,
    ],
];

$model = new Model($config);
$model->simulate(200);