MCIOBase Class Reference

Base class for all IO classes. More...

#include <mcllib/MCIOBase.h>

Inheritance diagram for MCIOBase:

List of all members.

Public Member Functions
mcllib::mcint64	available () const
	Get the amount of data available from the IO object.
void	close ()
	Close the IO object.
void *	getHandle () const
	Get a pointer to the implementation of the IO object.
bool	isOpen () const
	Test to see if the object is open.
bool	poll (mcintn pollFlags, mcinterval_t timeout) const
	Poll the IO object.
mcllib::mcint32	read (void *buf, mcllib::mcint32 size)
	Read data from the IO object.
void	setInherit (bool inherit)
	Allow/disallow an IO object to be inherited by child processes.
MCString	toString () const
	Get representation of the IO object as string for diagnostic purposes.
mcllib::mcint32	write (const void *buf, mcllib::mcint32 size)
	Write data to the IO object.
	~MCIOBase ()
	Destructor.
Static Public Attributes
const mcintn	MCPOLLALL
	Convenience indicating all poll flags.
const mcintn	MCPOLLEX
	Flag indicating interest in knowning about exception on the IO object.
const mcintn	MCPOLLRD
	Flag indicating interest in reading the IO object.
const mcintn	MCPOLLWR
	Flag indicating interest in writing the IO object.
Protected Member Functions
	MCIOBase (void *impl)
	Constructor from an implementation handle.
	MCIOBase ()
	Default constructor.

---

Detailed Description

Base class for all IO classes.

This base class provides methods which are common to all types of IO.

Derived class constructors may provide a pointer to a private implementation class derived from mclpriv::MCIOBaseImpl which is reference counted to allow fast and simple copying. It is still better to pass as const references instead of by value to avoid the reference counting overhead.

Todo:

Implement static poll method for several IO objects at once

---

Constructor & Destructor Documentation

~MCIOBase (   )

Destructor. The close method is called to ensure resource are freed up.

MCIOBase (   )  [protected]

Default constructor. Creates an unnamed, unopen IO object.

MCIOBase (  void *  impl  )  [protected]

Constructor from an implementation handle. impl must point to an object derived from MCIOBaseImpl.

---

Member Function Documentation

mcllib::mcint64 available (   )  const

Get the amount of data available from the IO object. If the operation fails an exception is thrown. Returns: the number of bytes of data available

void close (   )

Close the IO object. Frees up any resources that may have been allocated. All calls to close() after the first one are ignored.

void* getHandle (   )  const

Get a pointer to the implementation of the IO object. Returns: a pointer to the implementation object

bool isOpen (   )  const

Test to see if the object is open. Returns: true if the IO object is open.

bool poll (  mcintn  pollFlags, mcinterval_t  timeout )  const

Poll the IO object. Poll is used to test whether it is possible to read from or write to the object, or if the object is in error. Parameters: pollFlags  indicates what to poll for. timeout  indicates how long to wait. Returns: false if the timeout elapses before the read or write can occur or before the object is in error. Otherwise returns true.

mcllib::mcint32 read (  void *  buf, mcllib::mcint32  size )

Read data from the IO object. If the read fails an exception is thrown. Parameters: buf  must point to a region of memory of at least size bytes size  the number of bytes to read into the buffer Returns: the number of bytes actually read. A return value of zero indicates that no more data is available.

void setInherit (  bool  inherit  )

Allow/disallow an IO object to be inherited by child processes. If the IO object cannot have its inherit state changed an exception will be thrown. Parameters: inherit  specifies whether the object can be inherited. If inherit is true the IO object will be inherited by child processes. If inherit is false the IO object will not be inherited by child processes. When IO objects are created they are not automatically inherited by child processes.

MCString toString (   )  const

Get representation of the IO object as string for diagnostic purposes. Returns: a string representing the IO object

mcllib::mcint32 write (  const void *  buf, mcllib::mcint32  size )

Write data to the IO object. If the write fails an exception is thrown. Parameters: buf  must point to a region of memory of at least size bytes size  the number of bytes to read into the buffer Returns: the number of bytes actually written.

---