com::pcbsys::nirvana::client::nQueueReader Class Reference

This class is the base class for all Queue Readers and provides a generic reader interface. More...

#include <nQueueReader.h>

Inheritance diagram for com::pcbsys::nirvana::client::nQueueReader:

Public Member Functions
virtual void	close ()=0
	Close the subscription, and notify the server.
virtual void	closeLocally ()=0
	Close the subscription, but do not notify the server.
bool	hasConsumedEvents ()
	Method to see whether the reader has consumed any events. More...
bool	isClosed ()
	When a reader is closed, the physical subscription is closed at the server. More...
bool	isClosedLocally ()
	A reader can be closed, but the physical subscription queue is not closed at the server. More...
nConsumeEvent **	peek (nQueuePeekContext *pContext, int &nEvent)
	Performs a non destructive read. More...

Static Public Member Functions
static nQueuePeekContext *	createContext (int windowSize=0, const std::string &selector="")
	Creates a Queue Peek Context, which is used to traverse the queue. More...

Detailed Description

This class is the base class for all Queue Readers and provides a generic reader interface.

Member Function Documentation

static nQueuePeekContext* com::pcbsys::nirvana::client::nQueueReader::createContext ( int  windowSize = 0, const std::string &  selector = ""  )

static

Creates a Queue Peek Context, which is used to traverse the queue.

Parameters

windowSize	The size of the window over the queue to uses
selector	A message selector to be applied on the events received

Returns

A new nQueuePeekContext

bool com::pcbsys::nirvana::client::nQueueReader::hasConsumedEvents

(

)

Method to see whether the reader has consumed any events.

For transactional readers, this is reset every time commit or rollback is called.

Returns

true if any events have been consumed by the reader

bool com::pcbsys::nirvana::client::nQueueReader::isClosed

(

)

When a reader is closed, the physical subscription is closed at the server.

For Transactional readers, a close will rollback to the last committed event.

Returns

true if the reader has been closed

bool com::pcbsys::nirvana::client::nQueueReader::isClosedLocally

(

)

A reader can be closed, but the physical subscription queue is not closed at the server.

For Transactional readers, a local close will not rollback to the last committed event.

Returns

true if the reader has been closed locally but not at the server

nConsumeEvent** com::pcbsys::nirvana::client::nQueueReader::peek	(	nQueuePeekContext *	pContext,
		int &	nEvent
	)

Performs a non destructive read.

Parameters

*pContext	Peek Context to use. Used when multiple calls required to traverse a queue
nEvent	the length of the array

Returns

An Array of events

Exceptions

nSecurityException	If the client is not authorized to perform this request
nChannelNotFoundException	The queue was not found
nSessionNotConnectedException	Client is not currently connected to the server
nRequestTimedOutException	The server did not respond within the timeout
nUnexpectedResponseException	The server responded with an unexpected response
nIllegalArgumentException	Invalid parameters passed
nSessionPausedException	The session is currently paused, please resume
nIllegalStateException	The operation could not complete because of a session/connection error