driver.input

Example of input commands for the driver of the forwarding table. The syntax of commands is somehow similar to the syntax of C, especially that of literal values.

// 
// C-style and C++-style comments are allowed.
//
ifconfig 2      price < 500,
                dest = "MXP",
                classes ** "Y"                          // ** means substring
        |
                alert = "connection refused",
                host = "www.example.com",
                port = 23
        |
                auction_group =* "guitars/electric",    // =* means prefix
                maker = "PRS",
                price < 2000 
;
                
//
// interface numbers do not have to be consecutive, 
// nor they have to always increasing.  However, they have to be *unique*!
//
ifconfig 10     dest = "LGA",
                price < 300
        |
                system = "Siena",
                new_release = true
        |
                team > "d",
                team < "s",
                score > 0
;

//
// you can specify constaints for any value and/or any type.
//
ifconfig 20     dest any string,
                price < 300
        |
                system = "Siena",
                release any any
;

//
// if an attribute name starts with a digit, or if it contains special
// characters, you can quote it as a string.
//
ifconfig 30     dest = "LUG",
                price < 500,
                "30-day-cancellation" = true
;

//
// you can specify constaints for any value and/or any type.
//

//
// before using the forwarding table to process messages, 
// we *must* consolidate its data structures.  
//
%consolidate

//
// the driver has the ability to collect statistics regarding the
// forwarding table, including the amount of processing (user) time
//
%timer_start

select          carrier = "UA"
                orig = "DEN"
                dest = "MXP"
                price = 700
                stops = 1
                classes = "Q,Y,P,F" 
;

select          carrier = "UA"
                orig = "DEN"
                dest = "LGA"
                price = 200
                stops = 0
                classes = "Y,P"
;

%timer_stop
%print_statistics
//
// we can also change the number of pre-processing rounds here...
//
%pre_process_limit = 20
%timer_start

select          carrier = "UA"
                orig = "DEN"
                dest = "MXP"
                price = 700
                stops = 1
                classes = "Q,Y,P,QF" ;

select          carrier = "UA"
                orig = "DEN"
                dest = "LGA"
                price = 200
                stops = 0
                classes = "Y,P" ;
%timer_stop
//
// we can clear the forwarding table using this command
//
%clear
//
// %clear also deallocates all the memory used by the forwarding table
// in order to clear the table maintaining (i.e., recycling) the
// allocated memory, we could use this:
// 
// %clear_recycle
//

//
// The following directives are supported:
//
// %print_statistics [format-string]
// prints the current statistics using the given format string, or the
// preconfigured format string if none is given
//
// %statistics_only 
// only reads and counts the input predicates and messages, without
// compiling or a forwarding table.  This might be useful to count the
// number of filters, predicates, constraints, etc. in a particular
// file.
//
// %timer_start
// starts the performance timers
//
// %timer_stop
// stops the performance timers
//
// %output_on
// activates the normal output of the matcher 
//
// %output_off
// suppresses the normal output of the matcher
//
// %output_to [filename]
// redirects the output of the matcher to the given file, or to
// standard output if a name is not given
//
// %pre_process_limit = <N>
// sets the number of preprocessing rounds for the FwdTable algorithm.
//
// %clear
// clears the forwarding table.  This is necessary to reconstruct the
// table (from scratch).  This operation also releases the memory allocated
// for the forwwarding table.
//
// %clear_recycle
// clears the forwarding table without releasing the allocated memory.
// This means that the memory will be recycled for the new content of
// the table.
//
// %consolidate
// consolidates the current value of the forwarding table.  This is
// *necessary* before the forwarding table can be used for matching.
//