Php7 MongoDB session handler.

MongoSessionHandler.php

<?php

class MongoSessionHandler implements \SessionHandlerInterface
{

    public $client;
    public $database;
    public $collection;

    public function __construct($uri, $uriOptions = [], $driverOptions = [])
    {
        $this->client = new \MongoDB\Client($uri, $uriOptions, $driverOptions);
    }

    public function withDatabase($database)
    {
        $new = clone $this;
        $new->database = $database;
        return $new;
    }

    public function withCollection($collection)
    {
        $new = clone $this;
        $new->collection = $collection;
        return $new;
    }

    public function open($savePath, $sessionName)
    {
        return true;
    }

    public function close()
    {
        return true;
    }

    public function read($id)
    {
        return $this
            ->client
            ->{$this->database}
            ->{$this->collection}
            ->findOne(['sessionId' => $id])
            ->data;
    }

    public function write($id, $data)
    {
        $this->destroy($id);
        $this
            ->client
            ->{$this->database}
            ->{$this->collection}
            ->insertOne(['sessionId' => $id, 'data' => $data, 'createdAt' => time()]);
        return true;
    }

    public function destroy($id)
    {
        $this
            ->client
            ->{$this->database}
            ->{$this->collection}
            ->deleteOne(['sessionId' => $id]);
        return true;
    }

    public function gc($maxlifetime)
    {
        foreach ($this->client->{$this->database}->{$this->collection}->find() as $session) {
            if ($session->createdAt + $maxlifetime < time()) {
                $this
                    ->client
                    ->{$this->database}
                    ->{$this->collection}
                    ->deleteOne(['sessionId' => $session->sessionId]);
            }
        }
        return true;
    }
}

Usage.php

<?php
$sessionHandler = (new \System\MongoSessionHandler('mongodb://localhost:27017'))
    ->withDatabase('session')
    ->withCollection('session');
session_set_save_handler($sessionHandler, true);
session_start();