The IDM_State module offers loadable modules a means of keeping state between invocations — this is necessary should Cheesewire be run periodically via cron rather than by its own daemon. State-related data is stored in DBM files via Perl ties.

20.1. New Instance of a Loadable Module

Creation of an instance of a loadable module calls upon IDM_State:

    sub IDM_Template::new_template() {
        .
        .
        my $state = IDM_State->new(STATEMODE => $self->{SIDSCONFIG}->daemon_mode(),
                                   DBMFILE   => $self->{CLASS});

        $self->{STATE} = $state;
        $self->{STATE}->init_state(FIELD           => "LAST_RUN_TIME", 
                                   DEFLT_FIELD_VAL => $args{LAST_RUN_TIME});

        $self->{LOG} = Log->new(PREFIX    => $self->{CLASS}, 
                                MODULE    => $self->{CLASS},
                                STATE     => $self->{STATE}, 
                                .
                                .
      }

20.2. New Instance of the Log Class

Instance of the Log class need to know when to rotate:

    sub Log::new() {
        .
        .
        $self->{STATE}->init_state(FIELD => "LOG_LASTTIME", DEFLT_FIELD_VAL => time);
        .        
        .        
      }

    sub Log::append() {
        .
        .
        if (time > $self->{STATE}->get_state(FIELD => "LOG_LASTTIME") 
                 + $self->{MODSCFG}->module_rot_prd($self->{MODULE})) {

            $self->{STATE}->set_state(FIELD => "LOG_LASTTIME", FIELDVALUE => time);
            $self->rotate_log();
          }
        .
        .
      }