protected function addValue($key,$value,$expire)
{
    if ($expire == 0)
        return (bool)$this->executeCommand('SETNX',array($key,$value));

    if($this->executeCommand('SETNX',array($key,$value)))
    {
        $this->executeCommand('EXPIRE',array($key,$expire));
        return true;
    }
    else
        return false;
}

protected function connect()
{
    $this->_socket=@stream_socket_client(
        $this->hostname.':'.$this->port,
        $errorNumber,
        $errorDescription,
        $this->timeout ? $this->timeout : ini_get("default_socket_timeout"),
        $this->options
    );
    if ($this->_socket)
    {
        if($this->password!==null)
            $this->executeCommand('AUTH',array($this->password));
        $this->executeCommand('SELECT',array($this->database));
    }
    else
    {
        $this->_socket = null;
        throw new CException('Failed to connect to redis: '.$errorDescription,(int)$errorNumber);
    }
}

protected function deleteValue($key)
{
    return (bool)$this->executeCommand('DEL',array($key));
}

public function executeCommand($name,$params=array())
{
    if($this->_socket===null)
        $this->connect();

    array_unshift($params,$name);
    $command='*'.count($params)."\r\n";
    foreach($params as $arg)
        $command.='$'.$this->byteLength($arg)."\r\n".$arg."\r\n";

    fwrite($this->_socket,$command);

    return $this->parseResponse(implode(' ',$params));
}

protected function flushValues()
{
    return $this->executeCommand('FLUSHDB');
}

protected function getValue($key)
{
    return $this->executeCommand('GET',array($key));
}

protected function getValues($keys)
{
    $response=$this->executeCommand('MGET',$keys);
    $result=array();
    $i=0;
    foreach($keys as $key)
        $result[$key]=$response[$i++];
    return $result;
}

protected function setValue($key,$value,$expire)
{
    if ($expire==0)
        return (bool)$this->executeCommand('SET',array($key,$value));
    return (bool)$this->executeCommand('SETEX',array($key,$expire,$value));
}