Database Reference
In-Depth Information
<?
php
# Cookbook_Session.php: MySQL-based session storage module
require_once
"Cookbook.php"
;
# Define the handler routines
function
mysql_sess_open
(
$save_path
,
$sess_name
)
...
function
mysql_sess_close
()
...
function
mysql_sess_read
(
$sess_id
)
...
function
mysql_sess_write
(
$sess_id
,
$sess_data
)
...
function
mysql_sess_destroy
(
$sess_id
)
...
function
mysql_sess_gc
(
$gc_maxlife
)
...
# Initialize the connection identifier, select user-defined
# session handling, and register the handler routines
$mysql_sess_dbh
=
NULL
;
ini_set
(
"session.save_handler"
,
"user"
);
session_set_save_handler
(
"mysql_sess_open"
,
"mysql_sess_close"
,
"mysql_sess_read"
,
"mysql_sess_write"
,
"mysql_sess_destroy"
,
"mysql_sess_gc"
);
?>
The library file includes
Cookbook.php
so that it can access the connection routine for
opening a connection to the
cookbook
database. Then it defines the handler routines
(we'll get to the details of these functions shortly). Finally, it initializes the connection
identifier, tells PHP to get ready to use a user-defined session storage manager, and
registers the handler functions. Thus, a PHP script that wants to store sessions in MySQL
performs all the necessary setup simply by including the
Cookbook_Session.php
file:
require_once
"Cookbook_Session.php"
;
The interface provided by the
Cookbook_Session.php
library file ex‐
poses a global database connection identifier variable
(
$mysql_sess_conn
) and a set of handler routines named
mysql_sess_open()
,
mysql_sess_close()
, and so forth. Scripts that
use the library should avoid using these global names for other pur‐
poses.
Now let's implement each handler routine.
Opening a session.
PHP passes two arguments to this function: the save path and the
session name. The save path applies to file-based storage, and we don't need the session
