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Sweden-Number/dlls/ole32/stg_bigblockfile.c

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/******************************************************************************
*
* BigBlockFile
*
* This is the implementation of a file that consists of blocks of
* a predetermined size.
* 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.
*
* 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"
#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
* 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;
DWORD mapped_bytes;
LPVOID lpBytes;
LONG refcnt;
BlockBits readable_blocks;
BlockBits writable_blocks;
};
/***********************************************************
* Prototypes for private methods
*/
static void* BIGBLOCKFILE_GetMappedView(LPBIGBLOCKFILE This,
DWORD page_index);
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 MappedPage* BIGBLOCKFILE_CreatePage(LPBIGBLOCKFILE This,
ULONG page_index);
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));
}
/******************************************************************************
* BIGBLOCKFILE_Construct
*
* 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,
DWORD openFlags,
ULONG blocksize,
BOOL fileBased)
{
LPBIGBLOCKFILE This;
This = HeapAlloc(GetProcessHeap(), 0, sizeof(BigBlockFile));
if (This == NULL)
return NULL;
This->fileBased = fileBased;
This->flProtect = BIGBLOCKFILE_GetProtectMode(openFlags);
This->blocksize = blocksize;
This->maplist = NULL;
This->victimhead = NULL;
This->victimtail = NULL;
This->num_victim_pages = 0;
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 %u\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;
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 %u\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_EnsureExists
*
* Grows the file if necessary to make sure the block is valid.
*/
void BIGBLOCKFILE_EnsureExists(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);
}
}
/******************************************************************************
* BIGBLOCKFILE_SetSize
*
* Sets the size of the file.
*
*/
void BIGBLOCKFILE_SetSize(LPBIGBLOCKFILE This, ULARGE_INTEGER newSize)
{
if (This->filesize.u.LowPart == newSize.u.LowPart)
return;
TRACE("from %u to %u\n", This->filesize.u.LowPart, newSize.u.LowPart);
/*
* unmap all views, must be done before call to SetEndFile
*/
BIGBLOCKFILE_UnmapAllMappedPages(This);
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.
*
*/
ULARGE_INTEGER BIGBLOCKFILE_GetSize(LPBIGBLOCKFILE This)
{
return This->filesize;
}
/******************************************************************************
* 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;
BIGBLOCKFILE_UnlinkPage(page);
BIGBLOCKFILE_LinkHeadPage(&This->maplist, page);
}
return page;
}
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)
{
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;
if (This->flProtect == PAGE_READONLY)
desired_access = FILE_MAP_READ;
else
desired_access = FILE_MAP_WRITE;
page->lpBytes = MapViewOfFile(This->hfilemap, desired_access, 0,
lowoffset, numBytesToMap);
page->mapped_bytes = numBytesToMap;
}
else
{
page->lpBytes = (LPBYTE)This->pbytearray + lowoffset;
page->mapped_bytes = PAGE_SIZE;
}
TRACE("mapped page %u to %p\n", page->page_index, page->lpBytes);
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;
if (!BIGBLOCKFILE_MapPage(This, page))
{
HeapFree(GetProcessHeap(),0,page);
return NULL;
}
BIGBLOCKFILE_Zero(&page->readable_blocks);
BIGBLOCKFILE_Zero(&page->writable_blocks);
return page;
}
static void BIGBLOCKFILE_UnmapPage(LPBIGBLOCKFILE This, MappedPage *page)
{
TRACE("%d at %p\n", page->page_index, page->lpBytes);
if (page->refcnt > 0)
ERR("unmapping inuse page %p\n", page->lpBytes);
if (This->fileBased && page->lpBytes)
UnmapViewOfFile(page->lpBytes);
page->lpBytes = NULL;
}
static void BIGBLOCKFILE_DeletePage(LPBIGBLOCKFILE This, MappedPage *page)
{
BIGBLOCKFILE_UnmapPage(This, page);
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.
* 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 %u\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);
}
/****************************************************************************
* 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;
}
/* ILockByte Interfaces */
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* It reads a block of information from the byte array at the specified
* offset.
*
* See the documentation of ILockBytes for more info.
*/
static HRESULT WINAPI ImplBIGBLOCKFILE_ReadAt(
BigBlockFile* const This,
ULARGE_INTEGER ulOffset, /* [in] */
void* pv, /* [length_is][size_is][out] */
ULONG cb, /* [in] */
ULONG* pcbRead) /* [out] */
{
ULONG first_page = ulOffset.u.LowPart / PAGE_SIZE;
ULONG offset_in_page = ulOffset.u.LowPart % PAGE_SIZE;
ULONG bytes_left = cb;
ULONG page_index = first_page;
ULONG bytes_from_page;
LPVOID writePtr = pv;
HRESULT rc = S_OK;
TRACE("(%p)-> %i %p %i %p\n",This, ulOffset.u.LowPart, pv, cb, pcbRead);
/* verify a sane environment */
if (!This) return E_FAIL;
if (offset_in_page + bytes_left > PAGE_SIZE)
bytes_from_page = PAGE_SIZE - offset_in_page;
else
bytes_from_page = bytes_left;
if (pcbRead)
*pcbRead = 0;
while (bytes_left)
{
LPBYTE readPtr;
BOOL eof = FALSE;
MappedPage *page = BIGBLOCKFILE_GetMappedView(This, page_index);
if (!page || !page->lpBytes)
{
rc = STG_E_READFAULT;
break;
}
TRACE("page %i, offset %u, bytes_from_page %u, bytes_left %u\n",
page->page_index, offset_in_page, bytes_from_page, bytes_left);
if (page->mapped_bytes < bytes_from_page)
{
eof = TRUE;
bytes_from_page = page->mapped_bytes;
}
readPtr = (BYTE*)page->lpBytes + offset_in_page;
memcpy(writePtr,readPtr,bytes_from_page);
BIGBLOCKFILE_ReleaseMappedPage(This, page);
if (pcbRead)
*pcbRead += bytes_from_page;
bytes_left -= bytes_from_page;
if (bytes_left && !eof)
{
writePtr = (LPBYTE)writePtr + bytes_from_page;
page_index ++;
offset_in_page = 0;
if (bytes_left > PAGE_SIZE)
bytes_from_page = PAGE_SIZE;
else
bytes_from_page = bytes_left;
}
if (eof)
{
rc = STG_E_READFAULT;
break;
}
}
TRACE("finished\n");
return rc;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* It writes the specified bytes at the specified offset.
* position. If the file is too small, it will be resized.
*
* See the documentation of ILockBytes for more info.
*/
static HRESULT WINAPI ImplBIGBLOCKFILE_WriteAt(
BigBlockFile* const This,
ULARGE_INTEGER ulOffset, /* [in] */
const void* pv, /* [size_is][in] */
ULONG cb, /* [in] */
ULONG* pcbWritten) /* [out] */
{
ULONG size_needed = ulOffset.u.LowPart + cb;
ULONG first_page = ulOffset.u.LowPart / PAGE_SIZE;
ULONG offset_in_page = ulOffset.u.LowPart % PAGE_SIZE;
ULONG bytes_left = cb;
ULONG page_index = first_page;
ULONG bytes_to_page;
LPCVOID readPtr = pv;
HRESULT rc = S_OK;
TRACE("(%p)-> %i %p %i %p\n",This, ulOffset.u.LowPart, pv, cb, pcbWritten);
/* verify a sane environment */
if (!This) return E_FAIL;
if (This->flProtect != PAGE_READWRITE)
return STG_E_ACCESSDENIED;
if (size_needed > This->filesize.u.LowPart)
{
ULARGE_INTEGER newSize;
newSize.u.HighPart = 0;
newSize.u.LowPart = size_needed;
BIGBLOCKFILE_SetSize(This, newSize);
}
if (offset_in_page + bytes_left > PAGE_SIZE)
bytes_to_page = PAGE_SIZE - offset_in_page;
else
bytes_to_page = bytes_left;
if (pcbWritten)
*pcbWritten = 0;
while (bytes_left)
{
LPBYTE writePtr;
MappedPage *page = BIGBLOCKFILE_GetMappedView(This, page_index);
TRACE("page %i, offset %u, bytes_to_page %u, bytes_left %u\n",
page ? page->page_index : 0, offset_in_page, bytes_to_page, bytes_left);
if (!page)
{
ERR("Unable to get a page to write. This should never happen\n");
rc = E_FAIL;
break;
}
if (page->mapped_bytes < bytes_to_page)
{
ERR("Not enough bytes mapped to the page. This should never happen\n");
rc = E_FAIL;
break;
}
writePtr = (BYTE*)page->lpBytes + offset_in_page;
memcpy(writePtr,readPtr,bytes_to_page);
BIGBLOCKFILE_ReleaseMappedPage(This, page);
if (pcbWritten)
*pcbWritten += bytes_to_page;
bytes_left -= bytes_to_page;
if (bytes_left)
{
readPtr = (LPBYTE)readPtr + bytes_to_page;
page_index ++;
offset_in_page = 0;
if (bytes_left > PAGE_SIZE)
bytes_to_page = PAGE_SIZE;
else
bytes_to_page = bytes_left;
}
}
return rc;
}
HRESULT BIGBLOCKFILE_ReadAt(LPBIGBLOCKFILE This, ULARGE_INTEGER offset,
void* buffer, ULONG size, ULONG* bytesRead)
{
if (This->fileBased)
return ImplBIGBLOCKFILE_ReadAt(This,offset,buffer,size,bytesRead);
else
return ILockBytes_ReadAt(This->pLkbyt,offset,buffer,size,bytesRead);
}
HRESULT BIGBLOCKFILE_WriteAt(LPBIGBLOCKFILE This, ULARGE_INTEGER offset,
void* buffer, const ULONG size, ULONG* bytesRead)
{
if (This->fileBased)
return ImplBIGBLOCKFILE_WriteAt(This,offset,buffer,size,bytesRead);
else
return ILockBytes_WriteAt(This->pLkbyt,offset,buffer,size,bytesRead);
}
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