Custom Session Handler

<?php 

// config 
$m_host = ""; //MySQL Host 
$m_user = ""; //MySQL User 
$m_pass = ""; //MySQL Pass 
$m_db   = ""; //MySQL Database 

$session_expire = 600; // Session expire time, in seconds (minutes * 60 = seconds) 

$gc_probability = 50; // Probability that the garbage collection function will be called. 50% chance by default 

ini_set("session.gc_probability",$gc_probability); 

/* Open function; Opens/starts session 

   Opens a connection to the database and stays open until specifically closed 
   This function is called first and with each page load */ 

function open ($s,$n) // do not modify function parameters 
{ 
  global $session_connection, $m_host, $m_user, $m_pass, $m_db; 
  $session_connection = mysql_pconnect($m_host,$m_user,$m_pass); 
  mysql_select_db($m_db,$session_connection); 
  return true; 
} 

/* Read function; downloads data from repository to current session 

   Queries the mysql database, unencrypts data, and returns it. 
   This function is called after 'open' with each page load. */ 
function read ($id) // do not modify function parameters 
{ 
  global $session_connection,$session_read; 
  $query = "SELECT data FROM sess_data WHERE id=\"{$id}\""; 
  $res = mysql_query($query,$session_connection); 
  if(mysql_num_rows($res) != 1) return ""; // must return string, not 'false' 
  else 
  { 
    $session_read = mysql_fetch_assoc($res); 
    $session_read["data"] = base64_decode($session_read["data"]); 
    return $session_read["data"]; 
  } 
} 


/* Write function; uploads data from current session to repository 

   Inserts/updates mysql records of current session. Called after 'read' 
   with each page load */ 
function write ($id,$data) // do not modify function parameters 
{ 
  if(!$data) { return false; } 
  global $session_connection, $session_read, $session_expire; 
  $expire = time() + $session_expire; 
  $data = mysql_real_escape_string(base64_encode($data)); 
  if($session_read) $query = "UPDATE sess_data SET data=\"{$data}\", expire=\"{$expire}\" WHERE id=\"{$id}\""; 
  else $query = "INSERT INTO sess_data SET id=\"{$id}\", data=\"{$data}\""; 
  mysql_query($query,$session_connection); 
  return true; 
} 

/*Close function; closes session 

  closes mysql connection */ 
function close () 
{ 
  global $session_connection; 
  mysql_close($session_connection); 
  return true; 
} 


/* destroy function; deletes session data 

   deletes records of current session. called ONLY when function 'session_destroy()' 
   is called */ 
function destroy ($id) // do not modify function parameters 
{ 
  global $session_connection; 
  $query = "DELETE FROM sess_data WHERE id=\"{$id}\""; 
  mysql_query($query,$session_connection); 
  return true; 
} 

/* gc function; cleans expired sessions 

   deletes all rows where expire < time(); called with a $gc_probability chance of executing */ 
function gc ($expire) 
{ 
  global $session_connection; 
  $query = "DELETE FROM sess_data WHERE expire < ".time(); 
  mysql_query($query,$session_connection); 
} 


// Set custom handlers 
session_set_save_handler ("open", "close", "read", "write", "destroy", "gc"); 

// Start session 
session_start(); 
?>

// MySQL Database Description

create table sess_data (
id2 int not null auto_increment,
id text not null,
data text,
expire int not null,
primary key(id2)
);