#
# constructor
#
sub new {
	my $class = shift;
	my (%args) = @_;
	my $sessions = {};
	my $session = {};
	
	# settings / defaults
	my $session_id = $args{SESSION_ID} || "";
	my $full_db_path = $args{FILE} || die "session db filename not defined";
	my $timeout = ( $args{TIMEOUT} || $DEFAULT_TIMEOUT ) * 60; # and convert to seconds
	
	$sync_dbm_obj = tie(%{$sessions}, 'MLDBM::Sync', $full_db_path, O_CREAT|O_RDWR, 0640)
		or die "could not create / open db file $full_db_path: $!";

	for ( $session_id ) {

		if( $session_id ) {
			$sync_dbm_obj->Lock;
			my $aref = $sessions->{$session_id};

			if( $aref ) {
				my $timestamp = $aref->{timestamp};
				if( time() - $timestamp > $timeout ) {
					# session expired and has to be removed
					delete( $sessions->{$session_id} );
					$sync_dbm_obj->UnLock;
					$session_id = "";
					redo;
				}
				else {
					# update last access timestamp
					$aref->{timestamp} = time();
					$aref->{a_session}->{_timestamp} = time(); #debug only
					$sessions->{$session_id} = $aref;
					$sync_dbm_obj->UnLock;
					$session = $aref->{a_session};
				}
			}
			else {
				$sync_dbm_obj->UnLock;
				$session_id = "";
				redo;
			}
		}
		else {
			$session_id = create_session_id();
			$sync_dbm_obj->Lock;
			$sessions->{$session_id} = {
										a_session => { _session_id => $session_id,
													   _timestamp  => time() },   # debug only
										timestamp => time()
									};
			$session = $sessions->{$session_id}->{a_session};
			$sync_dbm_obj->UnLock;
		}
	}
	
	return bless $session, $class;
}

#
#
#
sub add_key {
	my $self = shift;
	my ($key, $value) = @_;
	
	$sync_dbm_obj->Lock;
	my $aref = $self;
	$aref->{$key} = $value;
	$self = $aref;
	$sync_dbm_obj->UnLock;
}

#
# general destructor
#
sub DESTROY {
	my $self = shift;
	
	undef $sync_dbm_obj;
	untie(%{$self});
};

##</code><code>##

my $session = MLDBMSession->new(FILE => "c:\\perl_user\sessions.db", SESSION_ID => $session_id, TIMEOUT => 100);
$session->add_key( value1 => 20 );

##</code><code>##

$VAR1 = bless( {
                 '_timestamp' => 1034001952,
                 'value1' => 20,
                 '_session_id' => '1ca9437eec103d4d533dc22b5b2c45ab'
               }, 'MLDBMSession' );
Time now: Mon Oct  7 10:45:52 2002

$VAR1 = {
          'a_session' => {
                           '_timestamp' => 1034001952,
                           '_session_id' => '1ca9437eec103d4d533dc22b5b2c45ab'
                         },
          'timestamp' => 1034001952
        };
Created/Last Accessed: Mon Oct  7 10:45:52 2002