implementation of a forwarding table based on an improved "counting" algorithm. More...

#include <fwdtable.h>

Inheritance diagram for siena::FwdTable:

Collaboration diagram for siena::FwdTable:

Public Member Functions
virtual void	ifconfig (if_t, const predicate &)
	Associates a predicate to an interface. More...

virtual void	consolidate ()
	Prepares the forwarding table for matching. More...

virtual void	match (const message &, MatchHandler &) const
	Processes a message, calling the output() function on the given MatchHandler object for each matching interface. More...

virtual void	match (const message &, MatchMessageHandler &) const
	Processes a message, calling the output() function on the given MatchMessageHandler object for each matching interface. More...

virtual void	clear ()
	Clears the forwarding table. More...

virtual void	clear_recycle ()
	Clears the forwarding table. More...

virtual size_t	allocated_bytesize () const
	Memory allocated by the forwarding table. More...

virtual size_t	bytesize () const
	Memory used by the forwarding table. More...

void	set_preprocess_rounds (unsigned int)
	Determines the number of pre-processing rounds applied to every message.

unsigned int	get_preprocess_rounds () const
	Returns the current number of pre-processing rounds.

Public Member Functions inherited from siena::ForwardingTable
virtual	~ForwardingTable ()
	Destroys the forwarding including all its internal data structures.

Detailed Description

implementation of a forwarding table based on an improved "counting" algorithm.

This class implements the index structure and matching algorithm described in "Forwarding in a Content-Based Network", Proceedings of ACM SIGCOMM 2003. p. 163-174. Karlsruhe, Germany. August, 2003.

In addition, this algorithm includes a number of improvements. The most notable one uses a fast containment check between the set of attribute names in the message and the constraint names of a candidate filter. If the check is negative, that is, if the set of attribute names is not a superset of the set of names of a candidate filter, then the algorithm does not even bother to "count" the number of matched constraints for that filter. The test is based on a representation of the set of names consisting of a Bloom filter.

Another improvement uses static counters to implement a faster but non-reentrant counting algorithm. This variant can be selected with the –with-non-reentrant-counters option at configure-time.

Examples:: forwarding_messages.cc.

Member Function Documentation

virtual size_t siena::FwdTable::allocated_bytesize ( ) const

virtual

Memory allocated by the forwarding table.

returns the number of bytes of memory allocated by the forwarding table. This value is always greater than or equal to the value returned by bytesize().

Implements siena::ForwardingTable.

virtual size_t siena::FwdTable::bytesize ( ) const

virtual

Memory used by the forwarding table.

returns the number of bytes of memory used by the forwarding table. This value is always less than or equal to the value returned by allocated_bytesize().

Implements siena::ForwardingTable.

virtual void siena::FwdTable::clear ( )

virtual

Clears the forwarding table.

This method removes all the associations from the forwarding table and releases allocated memory. After a call to this method, the forwarding table is ready to be configured with ifconfig().

See Also: ifconfig(); consolidate()

Implements siena::ForwardingTable.

virtual void siena::FwdTable::clear_recycle ( )

virtual

Clears the forwarding table.

This method removes all the associations from the forwarding table recycling the allocated memory. After a call to this method, the forwarding table is ready to be configured with ifconfig().

See Also: ifconfig(); consolidate()

Implements siena::ForwardingTable.

virtual void siena::FwdTable::consolidate ( )

virtual

Prepares the forwarding table for matching.

This function processes the forwarding table, packing some of its internal data structures and preparing them to be used to match events. This function must therefore be called after all the necessary calls to ifconfig and before matching messages with match().

The forwarding table can be reset by calling clear or clear_recycle.

See Also: clear(); recycle_clear()

Reimplemented from siena::ForwardingTable.

virtual void siena::FwdTable::ifconfig	(	if_t	,
		const predicate &
	)

virtual

Associates a predicate to an interface.

This is the method that constructs the forwarding table. This method must be called once for each interface, after the forwarding table is constructed or after it has been cleared. Using this method twice on the same interface without clearing the forwarding table has undefined effects.

See Also: consolidate()

Implements siena::ForwardingTable.

virtual void siena::FwdTable::match	(	const message &	,
		MatchHandler &
	)		const

virtual

Processes a message, calling the output() function on the given MatchHandler object for each matching interface.

Matches a message against the predicates stored in the forwarding table. The result is processed through the MatchHandler passed as a parameter to this function.

Notice that the forwarding table must be consolidated by calling siena::ForwardingTable::consolidate() before this function is called.

See Also: consolidate()

Implements siena::ForwardingTable.

Examples:: forwarding_messages.cc.

virtual void siena::FwdTable::match	(	const message &	,
		MatchMessageHandler &
	)		const

virtual

Processes a message, calling the output() function on the given MatchMessageHandler object for each matching interface.

See Also: consolidate(); ifconfig()

Implements siena::ForwardingTable.

Public Member Functions

Detailed Description

Member Function Documentation