Support functions
The MySQL-based session handlers use the showerror( ) function implemented in the error.inc include file, and the $hostName, $username, and $password variables set in the db.inc include file. The showerror( ) function is used by the handler implementations to display details about MySQL errors. The db.inc file provides a central location for maintaining connection details. The error.inc and db.inc files are described in Chapter 4.
Example D-2 shows the function getMicroTime( ), which generates a timestamp. The timestamp records the last session access in the sessionWrite( ) handler and creates a query that identifies idle sessions in the sessionGC( ) handler. The sessionWrite( ) handler and the sessionGC( ) handler are developed later in this section.
Example D-2. The support function getMicroTime( )
include("error.inc");
include("db.inc");
// Returns current time as a number.
// Used for recording the last session access.
function getMicroTime( )
{
// microtime( ) returns the number of seconds
// since 0:00:00 January 1, 1970 GMT as a
// microsecond part and a second part.
// e.g.: 0.08344800 1000952237
// Convert the two parts into an array
$mtime = explode(" ", microtime( ));
// Return the addition of the two parts
// e.g.: 1000952237.08344800
return($mtime[1] + $mtime[0]);
}