AxPipe::CSinkMemFile Class Reference

A CSink implemented with a memory mapped file as the destination. More...

#include <CFileMap.h>

Inheritance diagram for AxPipe::CSinkMemFile:

[legend]Collaboration diagram for AxPipe::CSinkMemFile:

[legend]List of all members.

Public Member Functions
CSinkMemFile *	Init (const TCHAR *szFileName, size_t cbChunk=64 *1024)
	Set file and chunk size.
	CSinkMemFile ()
	Initialize member variables etc.
virtual	~CSinkMemFile ()
	Additional destruction necessary...
Protected Member Functions
HANDLE	GetHandle ()
	Get the handle to the opened file.
bool	OutClose ()
	Close the file, as well as all mappings, set end of file etc.
CSeg *	OutGetSeg (size_t cb)
	Get a writeable segment, mapped to the output file if possible.
void	Out (CSeg *pSeg)
	Write a segment to the file, optimizing the case where it already is a mapping.
bool	OutOpen ()
	Open the file named in Init() for output.
Private Attributes
HANDLE	m_hFile
	The opened file.
HANDLE	m_hMapping
	The mapping of the file.
size_t	m_cbChunk
	The chunk size we send down stream.
longlong	m_cbFileSize
	The length of the file in bytes.
longlong	m_cbStreamPos
	The next file position to read a chunk from.
_TCHAR *	m_szFileName
	The provided file name, new[]'d and delete[]'d here.
longlong	m_cbInPos
	The file pointer position to get the next segment to write to.
longlong	m_cbOutPos
	The file pointer position to write the next output to.
longlong	m_cbMappingSize
	The size of the current mapping - changed dynamically.
CRITICAL_SECTION	m_CritSect
	Threading protection for certain code sections.

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Detailed Description

A CSink implemented with a memory mapped file as the destination.

Definition at line 102 of file CFileMap.h.

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Member Function Documentation

HANDLE AxPipe::CSinkMemFile::GetHandle (   )  [protected]

Get the handle to the opened file. Returns: An operating system handle to the open file. Definition at line 232 of file CFileMap.cpp. References m_hFile.

CSinkMemFile * AxPipe::CSinkMemFile::Init (  const TCHAR *  szFileName, size_t  cbChunk = 64*1024 )

Set file and chunk size. Parameters: szFileName  The name of the file, it is copied and saved here. cbChunk  The size of the chunks we provide upon request via OutGetSeg() upstream. Returns: A pointer to 'this' CSourceMemFile Definition at line 241 of file CFileMap.cpp. References _TCHAR, m_cbChunk, and m_szFileName.

void AxPipe::CSinkMemFile::Out (  CSeg *  pSeg  )  [protected, virtual]

Write a segment to the file, optimizing the case where it already is a mapping. Write a segment to the file by copying into a memory mapped segment, unless we're already such a segment, in which case we actually need do nothing except keep track of the length of valid data 'written'. Parameters: pSeg  The segment, possibly actually a CSegMap, determined by run time type info. Implements AxPipe::CSink. Definition at line 346 of file CFileMap.cpp. References _T, AxPipe::ERROR_CODE_GENERIC, AxPipe::CSegMap::GetPos(), AxPipe::CSeg::Len(), m_cbOutPos, m_CritSect, m_hMapping, AxPipe::MapUserView(), OutGetSeg(), AxPipe::CSeg::PtrRd(), AxPipe::CSeg::PtrWr(), AxPipe::CSeg::Release(), AxPipe::CSeg::RTClassId(), and AxPipe::CError::SetError().

bool AxPipe::CSinkMemFile::OutClose (  void   )  [protected, virtual]

Close the file, as well as all mappings, set end of file etc. Check for errors with GetErrorCode() Returns: true to propagate the close. Reimplemented from AxPipe::CSink. Definition at line 253 of file CFileMap.cpp. References _T, AxPipe::ERROR_CODE_GENERIC, m_cbOutPos, m_hFile, m_hMapping, and AxPipe::CError::SetError().

CSeg * AxPipe::CSinkMemFile::OutGetSeg (  size_t  cb  )  [protected, virtual]

Get a writeable segment, mapped to the output file if possible. Map a request for an output segment directly to the output file. If necessary, re-create a mapping to a possibly extended file. For this to be useful, the upstream caller must get segments in the same sequence that they are output, and also keep them the same size, i.e. not get a segment and then change the CSeg::Len() or CSeg::Drop() bytes off it. In fact using CSeg::Drop() will cause undefined effects. Shortening is possible, but strongly recommended against, as it will make the code quite inefficient. Parameters: cb  The size in bytes of the segment to get. Returns: A (possibly memory mapped) pointer to a CSeg of the requested size. Reimplemented from AxPipe::CSink. Definition at line 300 of file CFileMap.cpp. References _T, AxPipe::ERROR_CODE_GENERIC, AxPipe::longlong, m_cbInPos, m_cbMappingSize, m_cbOutPos, m_CritSect, m_hFile, m_hMapping, AxPipe::MapUserView(), and AxPipe::CError::SetError(). Referenced by Out().

bool AxPipe::CSinkMemFile::OutOpen (   )  [protected, virtual]

Open the file named in Init() for output. Check for errors with GetErrorCode(). Returns: true to propagate the open, which we do if no error. false is not an error condition. Reimplemented from AxPipe::CSink. Definition at line 399 of file CFileMap.cpp. References _T, AxPipe::ERROR_CODE_GENERIC, m_cbInPos, m_cbMappingSize, m_cbOutPos, m_hFile, m_szFileName, and AxPipe::CError::SetError().

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

• CFileMap.h
• CFileMap.cpp

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