Dispatcher Class Reference

Link between elements and operations. More...

#include <dispatcher.hh>

List of all members.

Classes
class	OpNotFound
	Exception thrown if no operation is found for given arguments. More...
union	Value
Public Types
typedef vector< const Element * >	ArgList
Public Member Functions
template<class L , class R , Element *(*)(const L &, const R &) funct>
void	add (const BinOper &op)
	Method to register a binary operation callback with dispatcher.
template<class T , Element *(*)(const T &) funct>
void	add (const UnOper &op)
	Method to register a unary operation callback with dispatcher.
Element *	run (const Oper &op, unsigned argc, const Element **argv) const
	Execute an n-ary operation.
Element *	run (const UnOper &op, const Element &arg) const
	Execute an unary operation.
Element *	run (const BinOper &op, const Element &left, const Element &right) const
	Execute a binary operation.
Private Types
typedef Element *(*	CB_bin )(const Element &, const Element &)
typedef Element *(*	CB_un )(const Element &)
typedef unsigned	Key
typedef map< Key, Value >	Map
Private Member Functions
Key	makeKey (const Oper &op, unsigned argc, const Element **argv) const
	Create a key for the callback table based on operation and arguments.
Value	lookup (const Oper &op, unsigned argc, const Element **argv) const
	Lookup a callback for the requested operation and elements.
Static Private Attributes
static Value	_map [32768]

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Detailed Description

Link between elements and operations.

Executes operations on elments.

Implementation of multimethods. Insipred/copied from Alexandrescu [Modern C++ Design].

By taking base element arguments and an operation, it will execute the correct operation based on the concrete type of the arguments.

Similar to an ElementFactory.

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Member Function Documentation

template<class L , class R , Element *(*)(const L &, const R &) funct>

void Dispatcher::add

(

const BinOper &

op

)

[inline]

Method to register a binary operation callback with dispatcher.

Parameters:

L	concrete class of first argument
R	concrete class of second argument
funct	function to be called to perform operation.
op	binary operation to be registered.

template<class T , Element *(*)(const T &) funct>

void Dispatcher::add

(

const UnOper &

op

)

[inline]

Method to register a unary operation callback with dispatcher.

Parameters:

T	concrete class of argument
funct	function to be called to perform operation.
op	unary operation to be registered.

Value Dispatcher::lookup	(	const Oper &	op,
		unsigned	argc,
		const Element **	argv
	)		const [inline, private]

Lookup a callback for the requested operation and elements.

Throws exception if none is found.

Returns:

callback which will perform requested operation.

Parameters:

op	operation to perform.
args	the arguments of the operation.

Key Dispatcher::makeKey	(	const Oper &	op,
		unsigned	argc,
		const Element **	argv
	)		const [inline, private]

Create a key for the callback table based on operation and arguments.

Returns:

key used for callback lookup.

Parameters:

op	requested operation.
args	the arguments for the operation.

Element * Dispatcher::run	(	const UnOper &	op,
		const Element &	arg
	)		const

Execute an unary operation.

Returns:

Result of operation. Caller is responsible for delete.

Parameters:

op	Operation to perform.
arg	Argument of operation.

Element * Dispatcher::run	(	const Oper &	op,
		unsigned	argc,
		const Element **	argv
	)		const

Execute an n-ary operation.

Throws an exception on failure.

Returns:

result of operation.

Parameters:

op	operation to dispatch.
args	arguments of operation.

Element * Dispatcher::run	(	const BinOper &	op,
		const Element &	left,
		const Element &	right
	)		const

Execute a binary operation.

Returns:

result of operation. Caller is responsible for delete.

Parameters:

op	Operation to perform.
left	first argument.
right	second argument.

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The documentation for this class was generated from the following files:

• /home/greearb/git/xorp.ct.github/xorp/policy/common/dispatcher.hh
• /home/greearb/git/xorp.ct.github/xorp/policy/common/dispatcher.cc