CRcSubscriber Class Reference

Description

Subscriber to follow an arbitrary set of resources.

A subscriber monitors any number of resources. The resources can be specified by their real URIs or alias names. Wildcards as well as presently unkown resources are allowed. Events can be fetched using the CRcEventProcessor mechanisms, typically Select() and PollEvent().

Note: All public methods must be called from the same thread. Subscribers are generally managed by the user/owner object. Internally, each remote host object owns one subscriber to serve subscriptions from the remote host to local resources.

Definition at line 1880 of file resources.H.

#include "resources.H"

Inheritance diagram for CRcSubscriber:

Friends
class	CResource

Registration ...
bool	Register (const char *_lid)
	Enable the subscriber, set its LID and GID. Caller remains owner of object. If '_lid' refers to an invalid string, 'false' is returned and a warning is emitted.
void	Unregister ()
	Clear and unregister the subscriber.

Properties and stringification ...
const char *	Lid ()
const char *	Gid ()
virtual const char *	TypeId ()
	(optional) Hint for the main event loop: object type
virtual const char *	InstId ()
	(optional) Hint for the main event loop: object instance
const char *	ToStr (CString *ret)
bool	IsEmpty ()

Adding/removing resources ...
CResource *	AddResource (CResource *rc)
CResource *	AddResources (const char *pattern)
	Add new resources by pattern. The pattern is also stored internally to catch possible resources added in the future. More...
void	DelResource (CResource *rc)
void	DelResources (const char *pattern)
	Remove resources by pattern. See AddResources() for details on possible patterns. More...
void	Clear ()
	Remove all resources.

Synonyms for adding/removing resources (mainly for the Python wrappers) ...
CResource *	Subscribe (CResource *rc)
CResource *	Subscribe (const char *uri)
void	Unsubscribe (CResource *rc)
void	Unsubscribe (const char *pattern)

For directory services ...
void	GetInfo (CString *ret, int verbosity=1)
	Get Info. 'verbosity == 0': single line, 1: list entries / resources.
void	GetPatternSet (CKeySet *retPatternSet)
	Get current pattern set. Patterns from the watch set are followed by a "?".
void	PrintInfo (FILE *f=stdout, int verbosity=1)
static void	GetInfoAll (CString *ret, int verbosity=1)
	Get info for all subscribers of this instance (see GetInfo() for info on 'verbosity').

Additional Inherited Members
Public Member Functions inherited from CRcEventProcessor
void	PutEvent (CRcEvent *ev)
	Enqueue/process an event; caller remains owner of 'ev'.
bool	PollEvent (CRcEvent *ev)
	Check for an event (non-blocking) and return it at '*ev'. More...
bool	WaitEvent (CRcEvent *ev, TTicks *maxTime=NULL)
	Wait for an event and return it at '*ev'. More...
void	Interrupt ()
	Request a running WaitEvent() to stop now.
void	FlushEvents ()
	Remove all presently queued events; also waits until a concurrently running OnEvent() invocation returns.
virtual bool	OnEvent (CRcEvent *ev)
	Handle an event asynchronously (may have been called from any thread) More...
void	SetCbOnEvent (FRcEventFunc *_cbEvent, void *_cbEventData=NULL)
void	ClearCbOnEvent ()
void	SetInSelectSet (bool _inSelectSet)
	Set whether or not the event processor is contained in the set of upcoming Select() operations.
bool	InSelectSet ()
const char *	ToStr (CString *ret)
Static Public Member Functions inherited from CRcEventProcessor
static CRcEventProcessor *	Select (TTicks maxTime=-1)
	Wait until any of the existing 'CRcEventProcessor' objects has an event available. More...

Member Function Documentation

AddResources()

CResource* CRcSubscriber::AddResources

(

const char *

pattern

)

Add new resources by pattern. The pattern is also stored internally to catch possible resources added in the future.

Parameters

pattern

is a single or be a comma- or whitespace-separated list of URIs (expressions).

Returns

the resource, if 'pattern' refers to a single valid URI, or 'NULL' otherwise. It is allowed to pass multiple, comma-separated URIs or patterns here.

Within the resource expressions, both MQTT-style and filename-style wildcards can be used to select multiple resources:

• '?' matches any single character except '/'.
• '*' matches 0 or more characters except '/'.
• '+' matches 1 or more characters except '/'.
• '#' matches the complete remaining string (including '/' characters) and can thus be used to select a complete subtree. If used, '#' must be the last character in the expression. Anything behind a '#' is ignored silently.

DelResources()

void CRcSubscriber::DelResources

(

const char *

pattern

)

Remove resources by pattern. See AddResources() for details on possible patterns.

Note: When using wildcards, all patterns previously passed to AddResources() must either be covered completely or be identical. Otherwise, it may happen that not all resources covered by 'pattern' here are unsuscribed. For example, in the following sequence, the DelResources() call has no effect:

sub->AddResources ("/host/z3/a+");    // may subscribe to "host/z3/ab" and others
sub->DelResources ("/host/z3/+b");    // conflict with other pattern, i.e. "host/z3/ab" may remain subscribed

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

• resources/resources.H