Sweden-Number/dlls/ole32/stg_bigblockfile.c

852 lines
22 KiB
C
Raw Normal View History

/******************************************************************************
*
* BigBlockFile
*
2002-06-01 01:06:46 +02:00
* This is the implementation of a file that consists of blocks of
* a predetermined size.
2002-06-01 01:06:46 +02:00
* This class is used in the Compound File implementation of the
* IStorage and IStream interfaces. It provides the functionality
* to read and write any blocks in the file as well as setting and
* obtaining the size of the file.
* The blocks are indexed sequentially from the start of the file
* starting with -1.
2002-06-01 01:06:46 +02:00
*
* TODO:
* - Support for a transacted mode
*
* Copyright 1999 Thuy Nguyen
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <assert.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#define COBJMACROS
#define NONAMELESSUNION
#define NONAMELESSSTRUCT
#include "windef.h"
1999-02-28 20:14:33 +01:00
#include "winbase.h"
#include "winuser.h"
#include "winerror.h"
#include "objbase.h"
#include "ole2.h"
#include "storage32.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(storage);
/***********************************************************
* Data structures used internally by the BigBlockFile
* class.
*/
/* We map in PAGE_SIZE-sized chunks. Must be a multiple of 4096. */
#define PAGE_SIZE 131072
#define BLOCKS_PER_PAGE (PAGE_SIZE / BIG_BLOCK_SIZE)
/* We keep a list of recently-discarded pages. This controls the
* size of that list. */
#define MAX_VICTIM_PAGES 16
/* This structure provides one bit for each block in a page.
* Use BIGBLOCKFILE_{Test,Set,Clear}Bit to manipulate it. */
typedef struct
{
unsigned int bits[BLOCKS_PER_PAGE / (CHAR_BIT * sizeof(unsigned int))];
} BlockBits;
/***
* This structure identifies the paged that are mapped
2002-06-01 01:06:46 +02:00
* from the file and their position in memory. It is
* also used to hold a reference count to those pages.
*
* page_index identifies which PAGE_SIZE chunk from the
* file this mapping represents. (The mappings are always
* PAGE_SIZE-aligned.)
*/
struct MappedPage
{
MappedPage *next;
MappedPage *prev;
DWORD page_index;
LPVOID lpBytes;
LONG refcnt;
1999-03-12 18:06:46 +01:00
BlockBits readable_blocks;
BlockBits writable_blocks;
};
/***********************************************************
* Prototypes for private methods
*/
static void* BIGBLOCKFILE_GetMappedView(LPBIGBLOCKFILE This,
DWORD page_index);
1999-03-12 18:06:46 +01:00
static void BIGBLOCKFILE_ReleaseMappedPage(LPBIGBLOCKFILE This,
MappedPage *page);
static void BIGBLOCKFILE_FreeAllMappedPages(LPBIGBLOCKFILE This);
static void BIGBLOCKFILE_UnmapAllMappedPages(LPBIGBLOCKFILE This);
static void BIGBLOCKFILE_RemapAllMappedPages(LPBIGBLOCKFILE This);
static void* BIGBLOCKFILE_GetBigBlockPointer(LPBIGBLOCKFILE This,
1999-03-12 18:06:46 +01:00
ULONG index,
DWORD desired_access);
2002-06-01 01:06:46 +02:00
static MappedPage* BIGBLOCKFILE_GetPageFromPointer(LPBIGBLOCKFILE This,
void* pBlock);
static MappedPage* BIGBLOCKFILE_CreatePage(LPBIGBLOCKFILE This,
ULONG page_index);
1999-03-12 18:06:46 +01:00
static DWORD BIGBLOCKFILE_GetProtectMode(DWORD openFlags);
static BOOL BIGBLOCKFILE_FileInit(LPBIGBLOCKFILE This, HANDLE hFile);
static BOOL BIGBLOCKFILE_MemInit(LPBIGBLOCKFILE This, ILockBytes* plkbyt);
/* Note that this evaluates a and b multiple times, so don't
* pass expressions with side effects. */
#define ROUND_UP(a, b) ((((a) + (b) - 1)/(b))*(b))
/***********************************************************
* Blockbits functions.
*/
static inline BOOL BIGBLOCKFILE_TestBit(const BlockBits *bb,
unsigned int index)
{
unsigned int array_index = index / (CHAR_BIT * sizeof(unsigned int));
unsigned int bit_index = index % (CHAR_BIT * sizeof(unsigned int));
return bb->bits[array_index] & (1 << bit_index);
}
static inline void BIGBLOCKFILE_SetBit(BlockBits *bb, unsigned int index)
{
unsigned int array_index = index / (CHAR_BIT * sizeof(unsigned int));
unsigned int bit_index = index % (CHAR_BIT * sizeof(unsigned int));
bb->bits[array_index] |= (1 << bit_index);
}
static inline void BIGBLOCKFILE_ClearBit(BlockBits *bb, unsigned int index)
{
unsigned int array_index = index / (CHAR_BIT * sizeof(unsigned int));
unsigned int bit_index = index % (CHAR_BIT * sizeof(unsigned int));
bb->bits[array_index] &= ~(1 << bit_index);
}
static inline void BIGBLOCKFILE_Zero(BlockBits *bb)
{
memset(bb->bits, 0, sizeof(bb->bits));
}
1999-02-18 16:55:53 +01:00
/******************************************************************************
* BIGBLOCKFILE_Construct
*
2002-06-01 01:06:46 +02:00
* Construct a big block file. Create the file mapping object.
* Create the read only mapped pages list, the writable mapped page list
* and the blocks in use list.
*/
BigBlockFile * BIGBLOCKFILE_Construct(
HANDLE hFile,
ILockBytes* pLkByt,
1999-03-12 18:06:46 +01:00
DWORD openFlags,
ULONG blocksize,
BOOL fileBased)
{
LPBIGBLOCKFILE This;
This = HeapAlloc(GetProcessHeap(), 0, sizeof(BigBlockFile));
if (This == NULL)
return NULL;
This->fileBased = fileBased;
1999-05-12 12:36:17 +02:00
This->flProtect = BIGBLOCKFILE_GetProtectMode(openFlags);
This->blocksize = blocksize;
This->maplist = NULL;
This->victimhead = NULL;
This->victimtail = NULL;
This->num_victim_pages = 0;
1999-05-12 12:36:17 +02:00
if (This->fileBased)
{
if (!BIGBLOCKFILE_FileInit(This, hFile))
{
HeapFree(GetProcessHeap(), 0, This);
return NULL;
}
}
else
{
if (!BIGBLOCKFILE_MemInit(This, pLkByt))
{
HeapFree(GetProcessHeap(), 0, This);
return NULL;
}
}
return This;
}
/******************************************************************************
* BIGBLOCKFILE_FileInit
*
* Initialize a big block object supported by a file.
*/
static BOOL BIGBLOCKFILE_FileInit(LPBIGBLOCKFILE This, HANDLE hFile)
{
This->pLkbyt = NULL;
This->hbytearray = 0;
This->pbytearray = NULL;
This->hfile = hFile;
if (This->hfile == INVALID_HANDLE_VALUE)
return FALSE;
This->filesize.u.LowPart = GetFileSize(This->hfile,
&This->filesize.u.HighPart);
if( This->filesize.u.LowPart || This->filesize.u.HighPart )
{
/* create the file mapping object
*/
This->hfilemap = CreateFileMappingA(This->hfile,
NULL,
This->flProtect,
0, 0,
NULL);
if (!This->hfilemap)
{
CloseHandle(This->hfile);
return FALSE;
}
}
else
This->hfilemap = NULL;
This->maplist = NULL;
TRACE("file len %lu\n", This->filesize.u.LowPart);
return TRUE;
}
/******************************************************************************
* BIGBLOCKFILE_MemInit
*
* Initialize a big block object supported by an ILockBytes on HGLOABL.
*/
static BOOL BIGBLOCKFILE_MemInit(LPBIGBLOCKFILE This, ILockBytes* plkbyt)
{
This->hfile = 0;
2000-11-25 02:40:34 +01:00
This->hfilemap = 0;
/*
* Retrieve the handle to the byte array from the LockByte object.
*/
if (GetHGlobalFromILockBytes(plkbyt, &(This->hbytearray)) != S_OK)
{
FIXME("May not be an ILockBytes on HGLOBAL\n");
return FALSE;
}
This->pLkbyt = plkbyt;
/*
* Increment the reference count of the ILockByte object since
* we're keeping a reference to it.
*/
ILockBytes_AddRef(This->pLkbyt);
This->filesize.u.LowPart = GlobalSize(This->hbytearray);
This->filesize.u.HighPart = 0;
This->pbytearray = GlobalLock(This->hbytearray);
TRACE("mem on %p len %lu\n", This->pbytearray, This->filesize.u.LowPart);
return TRUE;
}
/******************************************************************************
* BIGBLOCKFILE_Destructor
*
* Destructor. Clean up, free memory.
*/
void BIGBLOCKFILE_Destructor(
LPBIGBLOCKFILE This)
{
BIGBLOCKFILE_FreeAllMappedPages(This);
if (This->fileBased)
{
CloseHandle(This->hfilemap);
CloseHandle(This->hfile);
}
else
{
GlobalUnlock(This->hbytearray);
ILockBytes_Release(This->pLkbyt);
}
/* destroy this
*/
HeapFree(GetProcessHeap(), 0, This);
}
/******************************************************************************
* BIGBLOCKFILE_GetROBigBlock
*
* Returns the specified block in read only mode.
* Will return NULL if the block doesn't exists.
*/
void* BIGBLOCKFILE_GetROBigBlock(
LPBIGBLOCKFILE This,
ULONG index)
{
/*
* block index starts at -1
* translate to zero based index
*/
if (index == 0xffffffff)
index = 0;
else
index++;
/*
* validate the block index
2002-06-01 01:06:46 +02:00
*
*/
if (This->blocksize * (index + 1)
> ROUND_UP(This->filesize.u.LowPart, This->blocksize))
{
TRACE("out of range %lu vs %lu\n", This->blocksize * (index + 1),
This->filesize.u.LowPart);
return NULL;
}
return BIGBLOCKFILE_GetBigBlockPointer(This, index, FILE_MAP_READ);
}
/******************************************************************************
* BIGBLOCKFILE_GetBigBlock
*
* Returns the specified block.
* Will grow the file if necessary.
*/
void* BIGBLOCKFILE_GetBigBlock(LPBIGBLOCKFILE This, ULONG index)
{
/*
* block index starts at -1
* translate to zero based index
*/
if (index == 0xffffffff)
index = 0;
else
index++;
/*
* make sure that the block physically exists
*/
if ((This->blocksize * (index + 1)) > This->filesize.u.LowPart)
{
ULARGE_INTEGER newSize;
newSize.u.HighPart = 0;
newSize.u.LowPart = This->blocksize * (index + 1);
BIGBLOCKFILE_SetSize(This, newSize);
}
return BIGBLOCKFILE_GetBigBlockPointer(This, index, FILE_MAP_WRITE);
}
/******************************************************************************
* BIGBLOCKFILE_ReleaseBigBlock
*
* Releases the specified block.
*/
void BIGBLOCKFILE_ReleaseBigBlock(LPBIGBLOCKFILE This, void *pBlock)
{
MappedPage *page;
if (pBlock == NULL)
return;
page = BIGBLOCKFILE_GetPageFromPointer(This, pBlock);
if (page == NULL)
return;
BIGBLOCKFILE_ReleaseMappedPage(This, page);
}
/******************************************************************************
* BIGBLOCKFILE_SetSize
*
* Sets the size of the file.
2002-06-01 01:06:46 +02:00
*
*/
void BIGBLOCKFILE_SetSize(LPBIGBLOCKFILE This, ULARGE_INTEGER newSize)
{
if (This->filesize.u.LowPart == newSize.u.LowPart)
return;
TRACE("from %lu to %lu\n", This->filesize.u.LowPart, newSize.u.LowPart);
/*
* unmap all views, must be done before call to SetEndFile
*/
BIGBLOCKFILE_UnmapAllMappedPages(This);
2002-06-01 01:06:46 +02:00
if (This->fileBased)
{
LARGE_INTEGER newpos;
newpos.QuadPart = newSize.QuadPart;
if (SetFilePointerEx(This->hfile, newpos, NULL, FILE_BEGIN))
{
if( This->hfilemap ) CloseHandle(This->hfilemap);
SetEndOfFile(This->hfile);
/*
* re-create the file mapping object
*/
This->hfilemap = CreateFileMappingA(This->hfile,
NULL,
This->flProtect,
0, 0,
NULL);
}
}
else
{
GlobalUnlock(This->hbytearray);
/*
* Resize the byte array object.
*/
ILockBytes_SetSize(This->pLkbyt, newSize);
/*
* Re-acquire the handle, it may have changed.
*/
GetHGlobalFromILockBytes(This->pLkbyt, &This->hbytearray);
This->pbytearray = GlobalLock(This->hbytearray);
}
This->filesize.u.LowPart = newSize.u.LowPart;
This->filesize.u.HighPart = newSize.u.HighPart;
BIGBLOCKFILE_RemapAllMappedPages(This);
}
/******************************************************************************
* BIGBLOCKFILE_GetSize
*
* Returns the size of the file.
2002-06-01 01:06:46 +02:00
*
*/
ULARGE_INTEGER BIGBLOCKFILE_GetSize(LPBIGBLOCKFILE This)
{
return This->filesize;
}
/******************************************************************************
* BIGBLOCKFILE_AccessCheck [PRIVATE]
*
* block_index is the index within the page.
*/
static BOOL BIGBLOCKFILE_AccessCheck(MappedPage *page, ULONG block_index,
DWORD desired_access)
{
assert(block_index < BLOCKS_PER_PAGE);
if (desired_access == FILE_MAP_READ)
{
if (BIGBLOCKFILE_TestBit(&page->writable_blocks, block_index))
return FALSE;
BIGBLOCKFILE_SetBit(&page->readable_blocks, block_index);
}
else
{
assert(desired_access == FILE_MAP_WRITE);
if (BIGBLOCKFILE_TestBit(&page->readable_blocks, block_index))
return FALSE;
BIGBLOCKFILE_SetBit(&page->writable_blocks, block_index);
}
return TRUE;
}
/******************************************************************************
* BIGBLOCKFILE_GetBigBlockPointer [PRIVATE]
*
* Returns a pointer to the specified block.
*/
static void* BIGBLOCKFILE_GetBigBlockPointer(
2002-06-01 01:06:46 +02:00
LPBIGBLOCKFILE This,
ULONG block_index,
DWORD desired_access)
{
DWORD page_index = block_index / BLOCKS_PER_PAGE;
DWORD block_on_page = block_index % BLOCKS_PER_PAGE;
MappedPage *page = BIGBLOCKFILE_GetMappedView(This, page_index);
if (!page || !page->lpBytes) return NULL;
if (!BIGBLOCKFILE_AccessCheck(page, block_on_page, desired_access))
{
BIGBLOCKFILE_ReleaseMappedPage(This, page);
return NULL;
}
return (LPBYTE)page->lpBytes + (block_on_page * This->blocksize);
}
/******************************************************************************
* BIGBLOCKFILE_GetMappedPageFromPointer [PRIVATE]
*
* pBlock is a pointer to a block on a page.
* The page has to be on the in-use list. (As oppsed to the victim list.)
*
* Does not increment the usage count.
*/
static MappedPage *BIGBLOCKFILE_GetPageFromPointer(LPBIGBLOCKFILE This,
void *pBlock)
{
MappedPage *page;
for (page = This->maplist; page != NULL; page = page->next)
{
if ((LPBYTE)pBlock >= (LPBYTE)page->lpBytes
&& (LPBYTE)pBlock <= (LPBYTE)page->lpBytes + PAGE_SIZE)
break;
}
return page;
}
/******************************************************************************
* BIGBLOCKFILE_FindPageInList [PRIVATE]
*
*/
static MappedPage *BIGBLOCKFILE_FindPageInList(MappedPage *head,
ULONG page_index)
{
for (; head != NULL; head = head->next)
{
if (head->page_index == page_index)
{
InterlockedIncrement(&head->refcnt);
break;
}
}
return head;
}
static void BIGBLOCKFILE_UnlinkPage(MappedPage *page)
{
if (page->next) page->next->prev = page->prev;
if (page->prev) page->prev->next = page->next;
}
static void BIGBLOCKFILE_LinkHeadPage(MappedPage **head, MappedPage *page)
{
if (*head) (*head)->prev = page;
page->next = *head;
page->prev = NULL;
*head = page;
}
/******************************************************************************
* BIGBLOCKFILE_GetMappedView [PRIVATE]
*
* Gets the page requested if it is already mapped.
* If it's not already mapped, this method will map it
*/
static void * BIGBLOCKFILE_GetMappedView(
LPBIGBLOCKFILE This,
DWORD page_index)
{
MappedPage *page;
page = BIGBLOCKFILE_FindPageInList(This->maplist, page_index);
if (!page)
{
page = BIGBLOCKFILE_FindPageInList(This->victimhead, page_index);
if (page)
{
This->num_victim_pages--;
BIGBLOCKFILE_Zero(&page->readable_blocks);
BIGBLOCKFILE_Zero(&page->writable_blocks);
}
}
if (page)
{
/* If the page is not already at the head of the list, move
* it there. (Also moves pages from victim to main list.) */
if (This->maplist != page)
{
if (This->victimhead == page) This->victimhead = page->next;
if (This->victimtail == page) This->victimtail = page->prev;
1999-03-12 18:06:46 +01:00
BIGBLOCKFILE_UnlinkPage(page);
BIGBLOCKFILE_LinkHeadPage(&This->maplist, page);
}
return page;
1999-03-12 18:06:46 +01:00
}
page = BIGBLOCKFILE_CreatePage(This, page_index);
if (!page) return NULL;
BIGBLOCKFILE_LinkHeadPage(&This->maplist, page);
return page;
}
static BOOL BIGBLOCKFILE_MapPage(LPBIGBLOCKFILE This, MappedPage *page)
{
DWORD lowoffset = PAGE_SIZE * page->page_index;
if (This->fileBased)
1999-03-12 18:06:46 +01:00
{
DWORD numBytesToMap;
DWORD desired_access;
if( !This->hfilemap )
return FALSE;
if (lowoffset + PAGE_SIZE > This->filesize.u.LowPart)
numBytesToMap = This->filesize.u.LowPart - lowoffset;
else
numBytesToMap = PAGE_SIZE;
1999-03-12 18:06:46 +01:00
if (This->flProtect == PAGE_READONLY)
desired_access = FILE_MAP_READ;
else
desired_access = FILE_MAP_WRITE;
1999-03-12 18:06:46 +01:00
page->lpBytes = MapViewOfFile(This->hfilemap, desired_access, 0,
lowoffset, numBytesToMap);
}
else
{
page->lpBytes = (LPBYTE)This->pbytearray + lowoffset;
}
TRACE("mapped page %lu to %p\n", page->page_index, page->lpBytes);
1999-03-12 18:06:46 +01:00
return page->lpBytes != NULL;
}
static MappedPage *BIGBLOCKFILE_CreatePage(LPBIGBLOCKFILE This,
ULONG page_index)
{
MappedPage *page;
page = HeapAlloc(GetProcessHeap(), 0, sizeof(MappedPage));
if (page == NULL)
return NULL;
page->page_index = page_index;
page->refcnt = 1;
page->next = NULL;
page->prev = NULL;
BIGBLOCKFILE_MapPage(This, page);
1999-02-24 11:52:26 +01:00
BIGBLOCKFILE_Zero(&page->readable_blocks);
BIGBLOCKFILE_Zero(&page->writable_blocks);
1999-03-12 18:06:46 +01:00
return page;
}
static void BIGBLOCKFILE_UnmapPage(LPBIGBLOCKFILE This, MappedPage *page)
{
TRACE("%ld at %p\n", page->page_index, page->lpBytes);
if (page->refcnt > 0)
ERR("unmapping inuse page %p\n", page->lpBytes);
1999-03-12 18:06:46 +01:00
if (This->fileBased && page->lpBytes)
UnmapViewOfFile(page->lpBytes);
page->lpBytes = NULL;
}
static void BIGBLOCKFILE_DeletePage(LPBIGBLOCKFILE This, MappedPage *page)
{
BIGBLOCKFILE_UnmapPage(This, page);
1999-03-12 18:06:46 +01:00
HeapFree(GetProcessHeap(), 0, page);
}
/******************************************************************************
* BIGBLOCKFILE_ReleaseMappedPage [PRIVATE]
*
* Decrements the reference count of the mapped page.
*/
static void BIGBLOCKFILE_ReleaseMappedPage(
LPBIGBLOCKFILE This,
MappedPage *page)
{
assert(This != NULL);
assert(page != NULL);
/* If the page is no longer refenced, move it to the victim list.
* If the victim list is too long, kick somebody off. */
if (!InterlockedDecrement(&page->refcnt))
{
if (This->maplist == page) This->maplist = page->next;
BIGBLOCKFILE_UnlinkPage(page);
if (MAX_VICTIM_PAGES > 0)
{
if (This->num_victim_pages >= MAX_VICTIM_PAGES)
{
MappedPage *victim = This->victimtail;
if (victim)
{
This->victimtail = victim->prev;
if (This->victimhead == victim)
This->victimhead = victim->next;
BIGBLOCKFILE_UnlinkPage(victim);
BIGBLOCKFILE_DeletePage(This, victim);
}
}
else This->num_victim_pages++;
BIGBLOCKFILE_LinkHeadPage(&This->victimhead, page);
if (This->victimtail == NULL) This->victimtail = page;
}
else
BIGBLOCKFILE_DeletePage(This, page);
}
}
static void BIGBLOCKFILE_DeleteList(LPBIGBLOCKFILE This, MappedPage *list)
{
while (list != NULL)
{
MappedPage *next = list->next;
BIGBLOCKFILE_DeletePage(This, list);
list = next;
}
}
/******************************************************************************
* BIGBLOCKFILE_FreeAllMappedPages [PRIVATE]
*
* Unmap all currently mapped pages.
1999-03-12 18:06:46 +01:00
* Empty mapped pages list.
*/
static void BIGBLOCKFILE_FreeAllMappedPages(
LPBIGBLOCKFILE This)
{
BIGBLOCKFILE_DeleteList(This, This->maplist);
BIGBLOCKFILE_DeleteList(This, This->victimhead);
This->maplist = NULL;
This->victimhead = NULL;
This->victimtail = NULL;
This->num_victim_pages = 0;
}
static void BIGBLOCKFILE_UnmapList(LPBIGBLOCKFILE This, MappedPage *list)
{
for (; list != NULL; list = list->next)
{
BIGBLOCKFILE_UnmapPage(This, list);
}
}
static void BIGBLOCKFILE_UnmapAllMappedPages(LPBIGBLOCKFILE This)
{
BIGBLOCKFILE_UnmapList(This, This->maplist);
BIGBLOCKFILE_UnmapList(This, This->victimhead);
}
static void BIGBLOCKFILE_RemapList(LPBIGBLOCKFILE This, MappedPage *list)
{
while (list != NULL)
{
MappedPage *next = list->next;
if (list->page_index * PAGE_SIZE > This->filesize.u.LowPart)
{
TRACE("discarding %lu\n", list->page_index);
/* page is entirely outside of the file, delete it */
BIGBLOCKFILE_UnlinkPage(list);
BIGBLOCKFILE_DeletePage(This, list);
}
else
{
/* otherwise, remap it */
BIGBLOCKFILE_MapPage(This, list);
}
list = next;
}
}
static void BIGBLOCKFILE_RemapAllMappedPages(LPBIGBLOCKFILE This)
{
BIGBLOCKFILE_RemapList(This, This->maplist);
BIGBLOCKFILE_RemapList(This, This->victimhead);
}
1999-02-18 16:55:53 +01:00
/****************************************************************************
* BIGBLOCKFILE_GetProtectMode
*
* This function will return a protection mode flag for a file-mapping object
* from the open flags of a file.
*/
static DWORD BIGBLOCKFILE_GetProtectMode(DWORD openFlags)
{
switch(STGM_ACCESS_MODE(openFlags))
{
case STGM_WRITE:
case STGM_READWRITE:
return PAGE_READWRITE;
}
return PAGE_READONLY;
1999-02-18 16:55:53 +01:00
}