RWPortal Class Reference

An access point to a reliable byte stream communication channel. More...

#include <rw/network/RWPortal.h>

Inheritance diagram for RWPortal:

Public Member Functions
	RWPortal ()
	RWPortal (const RWPortal &x)
	~RWPortal ()
RWPortal &	operator= (const RWPortal &x)
RWNetBuf	recv () const
int	recv (char *buf, int bufLen, RWNetBuf::State *state=0) const
RWNetBuf	recvAtLeast (int n) const
int	recvAtLeast (char *buf, int bufLen, int n, RWNetBuf::State *state=0) const
int	send (const RWCString &s) const
int	send (const char *buf, int buflen) const
int	sendAtLeast (const char *buf, int bufLen, int n) const
void	sendAtLeast (const char *buf, int bufLen) const
int	sendAtLeast (const RWCString &s, int n) const
void	sendAtLeast (const RWCString &s) const

Protected Member Functions
	RWPortal (RWPortalImp *impl)
const RWPortalImp *	implementation () const
RWPortalImp *	implementation ()

Friends
bool	operator== (const RWPortal &p, const RWPortal &q)

Detailed Description

RWPortal is an access point to a reliable byte stream communication channel. It is possible for more than one RWPortal to access the same communications channel. This happens, for example, when using the copy constructor and assignment operator. Unless explicitly constructed otherwise, portal classes are designed so that when the last portal into a channel disappears, the communications channel is closed.

RWPortal is a lightweight object. In addition, the copy constructor and the assignment operator copy only the RWPortal and not the underlying communications channel, which means that those operations are inexpensive. As a result, RWPortals can be returned by value from functions and used as member data in objects.

RWPortal is implemented using the interface/implementation design pattern as described in the Essential Networking Module User's Guide. The RWPortal itself is really a handle to an implementation that represents the communication channel.

Constructor & Destructor Documentation

RWPortal::RWPortal ( )

inline

Creates a portal that cannot send or receive. Trying to send or receive throws an RWNetNoChannelError exception.

RWPortal::RWPortal ( const RWPortal &  x )

inline

Copy constructor.

RWPortal::~RWPortal ( )

inline

Destroys this portal. If other portals were created from this one by assignment or copying, they are unaffected.

RWPortal::RWPortal ( RWPortalImp *  impl )

inlineprotected

Specifies the portal implementation. This constructor is used by derived classes that create specific types of portals by passing in specific types of portal implementations. The argument, like all RWPortalImp instances, must live on the heap.

Member Function Documentation

const RWPortalImp* RWPortal::implementation ( ) const

inlineprotected

Provides derived classes access to the underlying implementation.

RWPortalImp* RWPortal::implementation ( )

inlineprotected

Provides derived classes access to the underlying implementation.

RWPortal & RWPortal::operator= ( const RWPortal &  x )

inline

Assignment operator. Makes self a portal to the same channel as x. Disconnects from the current channel, if any.

RWNetBuf RWPortal::recv ( void  ) const

inline

Receives a buffer of data. The version returning an int returns the number of characters actually received. recv() makes only one call to the communications channel.

int RWPortal::recv	(	char *	buf,
		int	bufLen,
		RWNetBuf::State *	state = 0
	)		const

Receives a buffer of data. The version returning an int returns the number of characters actually received. recv() makes only one call to the communications channel.

RWNetBuf RWPortal::recvAtLeast

(

int

n

)

const

Receives at least n characters into the buffer. The second version returns the number of bytes actually received. The implementation loops over recv() until either all the data is received or, for some reason, no data is returned. If no data is returned by recv(), an RWNetCantRecvError exception is thrown. If you call recvAtLeast() on a non-blocking channel, it will probably throw this same exception.

int RWPortal::recvAtLeast	(	char *	buf,
		int	bufLen,
		int	n,
		RWNetBuf::State *	state = 0
	)		const

Receives at least n characters into the buffer. The second version returns the number of bytes actually received. The implementation loops over recv() until either all the data is received or, for some reason, no data is returned. If no data is returned by recv(), an RWNetCantRecvError exception is thrown. If you call recvAtLeast() on a non-blocking channel, it will probably throw this same exception.

int RWPortal::send ( const RWCString &  s ) const

inline

Sends a buffer of data. Returns the number of bytes actually sent. send() makes only one call to the communications channel.

int RWPortal::send ( const char *  buf, int  buflen  ) const

inline

Sends a buffer of data. Returns the number of bytes actually sent. send() makes only one call to the communications channel.

int RWPortal::sendAtLeast	(	const char *	buf,
		int	bufLen,
		int	n
	)		const

Sends at least n characters into the communications channel. If n is omitted, all data is sent where appropriate, and the number of bytes actually sent is returned. The implementation loops over send() to send the data. If any of the calls to send() cannot send any data, an RWNetCantSendError exception is thrown. If sendAtLeast() is called on a non-blocking channel, it will probably throw this same exception.

void RWPortal::sendAtLeast ( const char *  buf, int  bufLen  ) const

inline

Sends at least n characters into the communications channel. If n is omitted, all data is sent where appropriate, and the number of bytes actually sent is returned. The implementation loops over send() to send the data. If any of the calls to send() cannot send any data, an RWNetCantSendError exception is thrown. If sendAtLeast() is called on a non-blocking channel, it will probably throw this same exception.

int RWPortal::sendAtLeast ( const RWCString &  s, int  n  ) const

inline

Sends at least n characters into the communications channel. If n is omitted, all data is sent where appropriate, and the number of bytes actually sent is returned. The implementation loops over send() to send the data. If any of the calls to send() cannot send any data, an RWNetCantSendError exception is thrown. If sendAtLeast() is called on a non-blocking channel, it will probably throw this same exception.

void RWPortal::sendAtLeast

(

const RWCString &

s

)

const

Sends at least n characters into the communications channel. If n is omitted, all data is sent where appropriate, and the number of bytes actually sent is returned. The implementation loops over send() to send the data. If any of the calls to send() cannot send any data, an RWNetCantSendError exception is thrown. If sendAtLeast() is called on a non-blocking channel, it will probably throw this same exception.

Friends And Related Function Documentation

bool operator== ( const RWPortal &  p, const RWPortal &  q  )

friend

Returns true if p and q both use the same underlying portal implementation object.