You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
2.3 KiB
86 lines
2.3 KiB
//Copyright (c) 1997-2000 Microsoft Corporation
|
|
|
|
// Memory mapped file routines
|
|
|
|
#include "precomp.h"
|
|
#include "mappedfile.h"
|
|
|
|
BOOL CMemMappedFile::Open(
|
|
LPCTSTR szName, // name of the mapped file
|
|
unsigned long ulMemSize // size of the mapped file
|
|
)
|
|
{
|
|
// assumption: the code isn't going to call Open twice w/different szName
|
|
if (!m_hMappedFile)
|
|
{
|
|
// Create the mapped file from system page file. If it has been created
|
|
// previously, then CreateFileMapping acts like OpenFileMapping.
|
|
|
|
m_hMappedFile = CreateFileMapping(
|
|
INVALID_HANDLE_VALUE, // Current file handle.
|
|
NULL, // Default security.
|
|
PAGE_READWRITE, // Read/write permission.
|
|
0, // Hi-order DWORD of file size
|
|
ulMemSize, // Lo-order DWORD of file size
|
|
szName); // Name of mapping object.
|
|
|
|
if (!m_hMappedFile)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
// Note if this is the first open for the file?
|
|
m_fFirstOpen = (GetLastError() == ERROR_SUCCESS)?TRUE:FALSE;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
BOOL CMemMappedFile::AccessMem(
|
|
void **ppvMappedAddr // returned pointer into memory
|
|
)
|
|
{
|
|
if (IsBadWritePtr(ppvMappedAddr, sizeof(void *)))
|
|
return FALSE;
|
|
|
|
if (!m_hMappedFile)
|
|
return FALSE;
|
|
|
|
// Get a pointer to the mapped memory if we don't already have it
|
|
|
|
if (!m_pvMappedAddr)
|
|
{
|
|
m_pvMappedAddr = MapViewOfFile(
|
|
m_hMappedFile, // Handle to mapping object.
|
|
FILE_MAP_ALL_ACCESS, // Read/write permission
|
|
0, // Max. object size.
|
|
0, // Size of hFile.
|
|
0); // Map entire file.
|
|
|
|
*ppvMappedAddr = m_pvMappedAddr;
|
|
}
|
|
|
|
if (NULL == m_pvMappedAddr)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
void CMemMappedFile::Close()
|
|
{
|
|
if (m_pvMappedAddr)
|
|
{
|
|
UnmapViewOfFile(m_pvMappedAddr);
|
|
m_pvMappedAddr = 0;
|
|
}
|
|
|
|
if (m_hMappedFile)
|
|
{
|
|
CloseHandle(m_hMappedFile);
|
|
m_hMappedFile = 0;
|
|
}
|
|
|
|
m_fFirstOpen = FALSE;
|
|
}
|