How many users are online on the current page.

UsersOnlineService.php

<?php

namespace App\Services;

use Illuminate\Http\Request;
use Illuminate\Support\Facades\Redis;

/**
 * How many users are online on the current page.
 *
 *
 * use App\Services\UsersOnlineService;
 * 
 * class OtherClass
 * {
 *   protected $users_online;
 * 
 *   public function __construct(UsersOnlineService $users_online) {
 *     $this->users_online = $users_online;
 *   }
 * 
 *   public function anyMethod() {
 *     // Storing information about the current page
 *     $this->users_online->set();
 * 
 *     // Get the number of users on the current page.
 *     $this->users_online->get();
 * 
 *    // Count the number of users on the pages.
 *    // It is best to perform this function in the cron.
 *     $this->users_online->count();
 *   }
 * }
 */
class UsersOnlineService
{
    /**
     * @var string
     */
    protected $path = 'stats:online';

    /**
     * @var string
     */
    protected $page;

    /**
     * @var string
     */
    protected $session_id;

    /**
     * @var int
     */
    protected $ttl;

    protected $items;

    /**
     * @param \Illuminate\Http\Request $request
     */
    public function __construct(Request $request)
    {
        if ($request->hasSession()) {
            $this->session_id = $request->session()->getId() ?? null;
            $this->page       = md5($request->url());
        }

        $this->ttl   = now()->addMinutes(5)->timestamp;
        $this->items = collect([]);
    }

    public function set()
    {
        $key = $this->getKeyName($this->path, 'users', $this->page, $this->session_id);

        Redis::connection()->set($key, $this->session_id);
        Redis::connection()->expireat($key, $this->ttl);
    }

    /**
     * @return int
     */
    public function get()
    : int
    {
        $key = $this->getKeyName($this->path, 'count', $this->page);

        return (int) Redis::connection()->get($key) ?: 0;
    }

    public function count()
    {
        $name = $this->getKeyName($this->path, 'users', '*');
        $keys = Redis::connection()->keys($name);

        foreach ($keys as $key) {
            $id    = explode(':', $key)[3];
            $key   = $this->getKeyName($this->path, 'count', $id);
            $count = $this->getCount($id);

            Redis::connection()->set($key, $count);
            Redis::connection()->expireat($key, $this->ttl);
        }
    }

    /**
     * @param $id
     *
     * @return int|mixed
     */
    private function getCount($id)
    {
        if ($this->items->has($id)) {
            $count = $this->items->get($id) + 1;
        }
        else {
            $count = 1;
        }

        $this->items->put($id, $count);

        return $count;
    }

    private function getKeyName(...$params)
    : string
    {
        return implode(':', $params);
    }
}