A IODevice providing support for UDP and TCP sockets. More...

#include <SocketIODevice.h>

Inheritance diagram for nidas::core::SocketIODevice:

Public Member Functions
	SocketIODevice ()
	Create a SocketIODevice. More...

	~SocketIODevice ()

void	open (int flags) throw (nidas::util::IOException,nidas::util::InvalidParameterException)
	Prepare to open the socket. More...

void	ioctl (int, void *, size_t) throw (nidas::util::IOException)

virtual void	setName (const std::string &val)
	Set the device name to be opened for this sensor. More...

virtual const std::string &	getName () const

virtual int	getReadFd () const =0
	The file descriptor used when reading from this sensor. More...

virtual int	getWriteFd () const =0
	The file descriptor used when writing to this sensor. More...

virtual size_t	read (void *buf, size_t len)=0 throw (nidas::util::IOException)
	Read from the sensor. More...

virtual size_t	read (void *buf, size_t len, int msecTimeout)=0 throw (nidas::util::IOException)
	Read from the sensor with a millisecond timeout. More...

virtual size_t	getBytesAvailable () const throw (nidas::util::IOException)
	Return how many bytes are available to read on this IODevice. More...

virtual size_t	write (const void *buf, size_t len)=0 throw (nidas::util::IOException)
	Write to the sensor. More...

virtual void	close ()=0 throw (nidas::util::IOException)
	Close the device. More...

Static Public Member Functions
static void	parseAddress (const std::string &name, int &addrtype, std::string &hostname, int &port, std::string &bindaddr) throw (nidas::util::ParseException)
	Parse the getName() string to extract a socket type, destination address and optional port number. More...

Protected Attributes
int	_addrtype
	The type of the destination address, AF_INET or AF_UNIX. More...

std::string	_desthost
	Destination host name from sensor name. More...

int	_port
	Port number that is parsed from sensor name. More...

nidas::util::auto_ptr < nidas::util::SocketAddress >	_sockAddr
	The destination socket address. More...

std::string	_bindAddr
	The local bind socket address. More...

Detailed Description

A IODevice providing support for UDP and TCP sockets.

Constructor & Destructor Documentation

SocketIODevice::SocketIODevice ( )

Create a SocketIODevice.

No IO operations are performed in the constructor, hence no IOExceptions.

SocketIODevice::~SocketIODevice ( )

Member Function Documentation

virtual void nidas::core::IODevice::close	(		)
throw	(	nidas::util::IOException
	)

pure virtualinherited

Close the device.

Implemented in nidas::core::UnixIODevice, nidas::core::ServerSocketIODevice, nidas::core::UDPSocketIODevice, and nidas::core::TCPSocketIODevice.

Referenced by nidas::core::DSMSensor::close().

virtual size_t nidas::core::IODevice::getBytesAvailable	(		)	const
throw	(	nidas::util::IOException
	)

inlinevirtualinherited

Return how many bytes are available to read on this IODevice.

This method is only useful when ioctl FIONREAD is supported on this this IODevice, as for example with a UDP socket. It is not available, and not necessary, on most other devices, like serial ports, TCP sockets, or devices with nidas driver module support, in which case it will return an nidas::util::IOException. It is an optimization for use with UDP sockets, where after select determines that data is available on the socket file descriptor, a read will only read one datagram, even if there are more than one packet available, which would not be optimal if a sensor generated many small packets. Rather than returning back to select, we check if there are more datagrams to read. This is not necessary on other types of IODevices, where it is just a matter of using a big enough buffer to get all (or most) available data after a select.

According to man udp(7), FIONREAD will return 0 if the size of the next packet is 0. So, if select/poll indicate there is data available, one read at least should be done, just in case a sensor sends a datagram of length 0, otherwise it will never be consumed.

References err, nidas::core::IODevice::getName(), nidas::core::IODevice::getReadFd(), and nidas::core::IODevice::ioctl().

Referenced by nidas::core::DSMSensor::getBytesAvailable().

virtual const std::string& nidas::core::IODevice::getName ( ) const

inlinevirtualinherited

References nidas::core::IODevice::_devname.

Referenced by nidas::core::SerialPortIODevice::applyTermios(), nidas::core::TCPSocketIODevice::close(), nidas::core::UDPSocketIODevice::close(), nidas::core::ServerSocketIODevice::close(), nidas::core::UnixIODevice::close(), nidas::core::IODevice::getBytesAvailable(), ioctl(), nidas::core::ServerSocketIODevice::ioctl(), nidas::core::UnixIODevice::ioctl(), open(), nidas::core::ServerSocketIODevice::open(), nidas::core::UnixIODevice::open(), nidas::core::UnixIODevice::read(), and nidas::core::UnixIODevice::write().

virtual int nidas::core::IODevice::getReadFd ( ) const

pure virtualinherited

The file descriptor used when reading from this sensor.

Implemented in nidas::core::UnixIODevice, nidas::core::UDPSocketIODevice, nidas::core::ServerSocketIODevice, and nidas::core::TCPSocketIODevice.

Referenced by nidas::core::IODevice::getBytesAvailable(), and nidas::core::DSMSensor::getReadFd().

virtual int nidas::core::IODevice::getWriteFd ( ) const

pure virtualinherited

The file descriptor used when writing to this sensor.

Implemented in nidas::core::UnixIODevice, nidas::core::UDPSocketIODevice, nidas::core::ServerSocketIODevice, and nidas::core::TCPSocketIODevice.

Referenced by nidas::core::DSMSensor::getWriteFd().

void nidas::core::SocketIODevice::ioctl	(	int	,
		void *	,
		size_t
	)
throw	(	nidas::util::IOException
	)

inlinevirtual

Implements nidas::core::IODevice.

References nidas::core::IODevice::getName().

void SocketIODevice::open	(	int	flags	)
throw	(	nidas::util::IOException,
		nidas::util::InvalidParameterException
	)

virtual

Prepare to open the socket.

This actually just parses the address from the device name, and doesn't actually do a socket connection or bind. See parseAddress(). The connect or bind must be done in the TCPSocketIODevice or UDPSocketIODevice open method. If the name contains a IP hostname and the IP address of that host is not available, then an InvalidParameterException is thrown.

Implements nidas::core::IODevice.

Reimplemented in nidas::core::UDPSocketIODevice, and nidas::core::TCPSocketIODevice.

References _addrtype, _bindAddr, _desthost, _port, _sockAddr, nidas::util::Inet4Address::getByName(), nidas::core::IODevice::getName(), parseAddress(), and nidas::util::Exception::what().

Referenced by nidas::core::TCPSocketIODevice::open(), and nidas::core::UDPSocketIODevice::open().

void SocketIODevice::parseAddress	(	const std::string &	name,
		int &	addrtype,
		std::string &	hostname,
		int &	port,
		std::string &	bindaddr
	)
throw	(	nidas::util::ParseException
	)

static

Parse the getName() string to extract a socket type, destination address and optional port number.

The syntax of the set/getName() string is: ( "inet" | "sock" | "unix" | "blue" | "btspp" ) ':' address [:port] "inet" or "sock" indicate a TCP or UDP connection for use by derived classes implementing a TCP or UDP socket. The address field should then be a hostname which can be resolved to an IP address, or an IP address in dot notation. A port number is required for TCP/UDP socket connection. "unix" indicates a Unix socket connection, where address is the path name of the unix socket, for process to process communications. The port value is not used by unix sockets.

References port.

Referenced by nidas::dynld::raf::PSI9116_Sensor::open(), open(), and nidas::core::ServerSocketIODevice::open().