ElementCastTracker Class Reference

Router configuration visitor that collects elements that match a certain cast. More...

#include <routervisitor.hh>

Inheritance diagram for ElementCastTracker:

Public Member Functions
	ElementCastTracker (Router *router, const String &name, bool stopAtFirst=true)
	Construct an ElementCastTracker.
bool	visit (Element *e, bool isoutput, int port, Element *from_e, int from_port, int distance)
	Visit an element.
Public Member Functions inherited from ElementTracker
	ElementTracker (Router *router)
	Construct an ElementTracker.
const Vector< Element * > &	elements () const
	Return the elements that matched.
int	size () const
	Return the number of matching elements.
Element *	operator[] (int i) const
	Return the i'th matching element.
const_iterator	begin () const
	Return an iterator for the first matching element.
const_iterator	end () const
	Return an iterator for the end of the container.
bool	contains (const Element *e) const
	Return true iff element e is a matching element.
void	insert (Element *e)
	Add element e to the set of matching elements.
void	clear ()
	Clear the set of matching elements.
Public Member Functions inherited from RouterVisitor
	RouterVisitor ()
	Construct an RouterVisitor.
virtual	~RouterVisitor ()
	Destroy an RouterVisitor.
virtual int	distance (Element *e, Element *from_e)
	return the distance between two neighbour elements

Additional Inherited Members
Public Types inherited from ElementTracker
typedef Vector< Element * >::const_iterator	const_iterator
	Iterator type.

Detailed Description

Router configuration visitor that collects elements that match a certain cast.

When passed to Router::visit_upstream() or Router::visit_downstream(), ElementCastTracker collects the closest elements that successfully cast to name. For instance, this code will find the closest Storage elements upstream of [0]e:

ElementCastTracker tracker(e->router(), "Storage");
e->router()->visit_upstream(e, 0, &tracker);
tracker.elements();  // a Vector<Element *> containing the Storage elements

Graph traversal stops at each matching element, so in the above example, a Storage element that is "behind" another Storage element won't be returned.

Constructor & Destructor Documentation

ElementCastTracker()

ElementCastTracker::ElementCastTracker ( Router *  router, const String &  name, bool  stopAtFirst = true  )

inline

Construct an ElementCastTracker.

Parameters

router	the router to be traversed
name	the cast of interest

Member Function Documentation

visit()

bool ElementCastTracker::visit ( Element *  e, bool  isoutput, int  port, Element *  from_e, int  from_port, int  distance  )

virtual

Visit an element.

Parameters

e	element being visited
isoutput	true for output ports, false for input ports
port	port number being visited
from_e	element by which e was reached
from_port	port by which e/port was reached
distance	connection distance in breadth-first search

Returns

true to continue traversing, false to stop

A Router configuration traversal calls this function once on each reached port. Configuration traversal is breadth-first; distance is the minimum connection distance from the traversal's start point to e/port. A traversal will call a port's visit() function at most once. from_e and from_port specify one port that is connected to e and port (there may be more than one). If isoutput is true, then e/port is an output port and from_e/from_port is an input port; if isoutput is false, the opposite holds.

The return value specifies whether traversal should continue through the e element. If it is true, then the traversal will continue based on e's packet flow specifier, via ports that connect to e/port (see Element::flow_code() for more).

The default implementation always returns true.

Reimplemented from RouterVisitor.

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

• include/click/routervisitor.hh
• lib/routervisitor.cc