Wefts::OSFileFuncWin Class Reference
[OS Cooperative File Function Extended Enviroment]

#include <wefts_coffee_win.h>

Inheritance diagram for Wefts::OSFileFuncWin:

[legend]Collaboration diagram for Wefts::OSFileFuncWin:

[legend]List of all members.

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Detailed Description

Implements COFFEE file specific extensions for MS-Windows.

This class is able to understand if the underlying system is capable to do asynchronous file or network operations via OVERLAPPED files; this is possible only with Windows 2000 or later, and only if the target file is not a memory-based character file (that is, a CONSOLE).

If the asynchronous file operations are available, they are used to cleanly cleanup the thread in case of cancellation. If they are not available, two actions may be taken: if cancellation is not allowed in the underlying windows specific OSTAIL, the a blocking read is performed. If cancellation is allowed, then a new thread is started, and the calling thread puts itself in wait for the I/O thread to terminate. The new thread is created with minimal resources available, and it hasn't any data to be cleaned.

In case of cancellation requests arriving while waiting for I/O thread to terminate, the target thread is canceled with TerminateThread(). This is sayed to be an unsafe method (From MSDN), but chances are for the system not allocating resources to be cleaned; this means that this cancellation scheme should be safe, but since internal documentation of ReadFile or WriteFile functions is not available, we cannot be certain.

Anyhow, whenever possible (i.e. whenever it is demonstrable that the I/O call may return data or error in a reasonable time), turn off cancellation BEFORE calling entering read or write methods.

Instead of instantiating OSFileFuncWin, use the typedef OSFileFunc, that is turned into the correct class depending on the host system.

See also:

How to use OS Cooperative File Function Extended Environment layer

Public Member Functions
	OSFileFuncWin (void *descriptor=0)
	~OSFileFuncWin ()
virtual CffStatus	open (std::string filespec, OpenMode openMode=OM_RO, LockMode lockMode=LM_SHARED)
virtual CffStatus	create (std::string filespec, CreateMode cMode=CM_ARCHIVE, LockMode lockMode=LM_EXCLUSIVE)
virtual void	getDescriptor (void *data) const
	To get the descriptor, pass a pointer to an integer where the descriptor will be placed.
virtual void	setDescriptor (void *data)
	To set the descriptor, pass a pointer to the integer.
virtual file_size_t	read (void *buffer, const file_size_t len)
virtual file_size_t	write (void *buffer, const file_size_t len)
virtual file_size_t	seek (const file_size_t position, const SeekWhence swFrom=SW_FROM_BEGIN)
virtual CffStatus	close ()
virtual void	setStdIn ()
	Use STDIN as the handle of this FileFunc object.
virtual void	setStdOut ()
	Use STDOUT as the handle of this FileFunc object.
virtual void	setStdErr ()
	Use STDERR as the handle of this FileFunc object.
Protected Member Functions
file_size_t	internal_rw (void *buffer, const file_size_t len, bool rw, bool bFile)
Protected Attributes
HANDLE	m_handle
HANDLE	m_evtComplete
LARGE_INTEGER	m_liSize
LARGE_INTEGER	m_liPos
bool	m_bOvlFiles

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Constructor & Destructor Documentation

Wefts::OSFileFuncWin::OSFileFuncWin (  void *  descriptor = 0  )

Wefts::OSFileFuncWin::~OSFileFuncWin (   )  [inline]

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Member Function Documentation

virtual CffStatus Wefts::OSFileFuncWin::close (   )  [virtual]

Implements Wefts::OSFileFuncBase.

virtual CffStatus Wefts::OSFileFuncWin::create (  std::string  filespec, CreateMode  cMode = CM_ARCHIVE, LockMode  lockMode = LM_EXCLUSIVE )  [virtual]

Implements Wefts::OSFileFuncBase.

virtual void Wefts::OSFileFuncWin::getDescriptor (  void *  data  )  const [inline, virtual]

To get the descriptor, pass a pointer to an integer where the descriptor will be placed. Implements Wefts::OSFileFuncBase.

file_size_t Wefts::OSFileFuncWin::internal_rw (  void *  buffer, const file_size_t  len, bool  rw, bool  bFile )  [protected]

virtual CffStatus Wefts::OSFileFuncWin::open (  std::string  filespec, OpenMode  openMode = OM_RO, LockMode  lockMode = LM_SHARED )  [virtual]

Implements Wefts::OSFileFuncBase.

virtual file_size_t Wefts::OSFileFuncWin::read (  void *  buffer, const file_size_t  len )  [inline, virtual]

Implements Wefts::OSFileFuncBase.

virtual file_size_t Wefts::OSFileFuncWin::seek (  const file_size_t  position, const SeekWhence  swFrom = SW_FROM_BEGIN )  [virtual]

Implements Wefts::OSFileFuncBase.

virtual void Wefts::OSFileFuncWin::setDescriptor (  void *  data  )  [inline, virtual]

To set the descriptor, pass a pointer to the integer. Implements Wefts::OSFileFuncBase.

virtual void Wefts::OSFileFuncWin::setStdErr (   )  [inline, virtual]

Use STDERR as the handle of this FileFunc object. Implements Wefts::OSFileFuncBase.

virtual void Wefts::OSFileFuncWin::setStdIn (   )  [inline, virtual]

Use STDIN as the handle of this FileFunc object. Implements Wefts::OSFileFuncBase.

virtual void Wefts::OSFileFuncWin::setStdOut (   )  [inline, virtual]

Use STDOUT as the handle of this FileFunc object. Implements Wefts::OSFileFuncBase.

virtual file_size_t Wefts::OSFileFuncWin::write (  void *  buffer, const file_size_t  len )  [inline, virtual]

Implements Wefts::OSFileFuncBase.

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Member Data Documentation

bool Wefts::OSFileFuncWin::m_bOvlFiles [protected]

HANDLE Wefts::OSFileFuncWin::m_evtComplete [protected]

HANDLE Wefts::OSFileFuncWin::m_handle [protected]

LARGE_INTEGER Wefts::OSFileFuncWin::m_liPos [protected]

LARGE_INTEGER Wefts::OSFileFuncWin::m_liSize [protected]

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

• wefts_coffee_win.h

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