优化功能，用于加速应用程序

Question

I use the following code to check some of the cases described in the comments. Unfortunately, it has come down page load speed. To improve the function and use them properly, what do you suggest, what do I do?

function insert() {
    if ($this - > session - > userdata('logged_in')) { //This is for test whether the user is logged in or not?
        if ($this - > siran - > access_level_active()) { //This is because the user name manager is active or not?
            if ($this - > siran - > access_level('1', '5')) { //This is for whether or not permission to access this page?
if($_POST){
                $this - > load - > view('admin/onepage');
}else{
        $this->session->set_flashdata('message_p', $this->lang->line('nopost'));
        redirect($this->session->userdata('previous_page'));
        }
            } else {
                $this - > session - > set_flashdata('message', $this - > lang - > line('notaccess'));
                redirect($this - > session - > userdata('previous_page'));
            }
        } else {
            $this - > session - > set_flashdata('message', $this - > lang - > line('noactive'));
            redirect('login', 'refresh');
        }
    } else {
        $this - > session - > set_flashdata('message', $this - > lang - > line('plslogin'));
        redirect('login', 'refresh');
    }
}

These three functions in library codeigniter:

public function access_level($mp, $access){
    //$mp = '1';
    $CI = &get_instance();
            $result = $CI->db->get_where('access_level', array('mainpage'=>$mp,'id_relation'=>$CI->session->userdata('id_relation')));
    $data = array();
    $out = array();
    foreach($result->result() as $row){
        $dv = json_decode($row->subpage);       
        $flat = array();        
        foreach ( $dv as $item ) {
            $flat = array_merge( $flat, explode( ',', $item ) );
        }       
        $out = array_merge( $out, $flat );
    }
    if(in_array($access, $out) || in_array('110', $out)){
        return  true;
    }else{
        return false;
    }
}
public function access_level_active(){
    //$mp = '1';
    $CI = &get_instance();
            $result = $CI->db->get_where('users', array('id'=>$CI->session->userdata('id')));
    if ($result->num_rows() > 0){
        $row = $result->row();
        return ($row->active == 1 ? true : false );
    }else{
        return false;
    }
}
function previous_page(){
    $CI = &get_instance();
    if ($CI->session->userdata('logged_in')) {
        if (isset($_SERVER['HTTP_REFERER']))
        {
            $CI->session->set_userdata('previous_page', $_SERVER['HTTP_REFERER']);
        }else
        {
            $CI->session->set_userdata('previous_page', base_url());
        }
    }
}

Answer 1

Your code doesn't look particularly intensive, the only thing that I would change is to limit the amount of times you nest if{}else{} statements within themselves, and move any repetition of code out to another function. For example I would personally rewrite your insert() code as follows (mainly because it just looks a lot cleaner).

Insert function:

function insert() {

    if (!$this->session->userdata('logged_in')) {
        $this->_flashRedirect('login', $this->lang->line('plslogin'));  
    }

    if (!$this->siran->access_level_active()) {
        $this->_flashRedirect('login', $this->lang->line('noactive'));  
    }

    if (!$this->siran->access_level('1', '5')) {
        $this->_flashRedirect($this->session->userdata('previous_page'), $this->lang->line('notaccess'));       
    }

    if($_POST){
        $this->load->view('admin/onepage');
    } else {
        $this->_flashRedirect($this->session->userdata('previous_page'), $this->lang->line('nopost'), 'message_p'); 
    }

}

Create a new function _flashRedirect() in your controller:

public function _flashRedirect($page, $message, $message_type = 'message') {
    $this->session->set_flashdata('message', $message);
    redirect($page, 'refresh');
}

As for speed, it sounds a lot more likely that your queries (mysql) are the cause of your performance issues. How many rows are you returning, how big are your tables?