PdoSessionHandler.php

<?php namespace Rakit\Session;

use SessionHandlerInterface;
use PDO;

class PdoSessionHandler implements SessionHandlerInterface {
    
    protected $connection;
    
    protected $tablename;
    
    protected $configs;
    
    public function __construct(PDO $connection, $tablename = 'sessions', array $configs = array()) {
        $this->connection = $connection;
        $this->tablename = $tablename;
        $this->configs = array_merge(array('col_sessid' => 'sess_id', 'col_data' => 'sess_data', 'col_last_activity' => 'last_activity'), $configs);
    }
    
    public function open($save_path, $sess_name) {
        return true;
    }
    
    public function read($sess_id) {
        $table = $this->tablename;
        $col_sessid = $this->configs['col_sessid'];
        $col_data = $this->configs['col_data'];
        $query = $this->connection->query("
            SELECT * FROM {$table} 
            WHERE {$col_sessid} = '$sess_id' 
            LIMIT 1
        ");
        
        $session = $query->fetch(PDO::FETCH_ASSOC);
        
        $this->exists = (false === empty($session));
        
        return $this->exists ? base64_decode($session[$col_data]) : '';
    }
    
    public function write($sess_id, $data) {
        $table = $this->tablename;
        $col_sessid = $this->configs['col_sessid'];
        $col_data = $this->configs['col_data'];
        $col_la = $this->configs['col_last_activity'];
        
        $data = base64_encode($data);
        $time = time();
        
        if ($this->exists) {
            $this->connection->query("
                UPDATE {$table} 
                SET 
                    {$col_data} = '{$data}',
                    {$col_la} = {$time}
                WHERE {$col_sessid} = '{$sess_id}'
            ");
        } 
        else {
            $this->connection->query("
                INSERT INTO {$table}
                ({$col_sessid}, {$col_data}, {$col_la})
                VALUES ('{$sess_id}','{$data}', {$time})
            ");
        }
        
        $this->exists = true;
    }
    
    public function close() {
        return true;
    }
    
    public function destroy($sess_id) {
        $table = $this->table;
        $col_sessid = $this->configs['col_sessid'];
        
        $this->connection->query("DELETE FROM {$table} WHERE {$col_sessid}='{$sess_id}'");
        
        return true;
    }
    
    public function gc($lifetime) {
        $table = $this->table;
        $col_la = $this->configs['col_last_activity'];
        $expired_time = time() - $lifetime;
        
        $this->connection->query("DELETE FROM {$table} WHERE {$col_la} <= {$expired_time}");
        
        return true;
    }
}