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Hey again.
Had such a great response on my last question so I thought I'd try it again.
Currently porting some C++ code into PB... but I'm kind stuck.
What the code does is to read some data from a shared memory of another program (not my program)
and also edit that programs user files.. lock it, edit and then release it.
Got the easy part ported, but I'm stuck at the point hwere I'm suppose to get data from the 'database'.
I'll post the code and if some old C++ coder could take a look at the code and help me out I'd be grateful.
I got some of the code ported.. but since I can't get it to get any info from the code it's more or less useless.
Any help would be appreciated.
(If I wasn't clear enough I'd like some help on how to read the data UID, GID, MODE, HASH and all the other info)
----------------
Dennis
------------------
Had such a great response on my last question so I thought I'd try it again.
Currently porting some C++ code into PB... but I'm kind stuck.
What the code does is to read some data from a shared memory of another program (not my program)
and also edit that programs user files.. lock it, edit and then release it.
Got the easy part ported, but I'm stuck at the point hwere I'm suppose to get data from the 'database'.
I'll post the code and if some old C++ coder could take a look at the code and help me out I'd be grateful.
Code:
#include "stdafx.h"
typedef struct _DATAITEM
{
UINT Uid;
UINT Gid;
UINT Mode;
UINT Crc32;
PCHAR FileName;
UINT l_FileName;
UINT Hash;
LPVOID Context;
UINT l_Context;
} DATAITEM, * LPDATAITEM, ** DATABASE;
HANDLE pHeap;
UINT Database_Read(HANDLE FileHandle, DATABASE *lpDataBase)
{
LPDATAITEM DataItem;
DATABASE DataBase;
DWORD Read;
PUINT Table, Offset;
UINT l_FileName, l_Context;
UINT i_Size, b_Size, db_Size, db_Version, b_Crc32, t_Size, i_Read;
t_Size = 512;
i_Read = 0;
Table = (PUINT)HeapAlloc(pHeap, NULL, t_Size * sizeof(UINT));
*lpDataBase = NULL;
if (! Table)
{
// Could not allocate memory
return 0;
}
if (! ReadFile(FileHandle, Table,2 * sizeof(UINT), &Read ,NULL))
{
// Could not read from file
goto CLEANUP;
}
db_Version = Table[0];
db_Size = Table[1];
if (db_Version != 0)
{
// Current database version is always zero
goto CLEANUP;
}
DataBase = (DATABASE)HeapAlloc(pHeap, NULL, sizeof(LPDATAITEM) * db_Size);
if (! DataBase)
{
// Could not allocate enough memory
goto CLEANUP;
}
for (; <IMG SRC="http://www.powerbasic.com/support/forums/wink.gif" ALT="wink">
{
if (! ReadFile(FileHandle, Table, 2 * sizeof(UINT), &Read, NULL) | | Read != 2 * sizeof(UINT))
{
// Could not read (enough?)
break;
}
// Get block size
b_Size = Table[0];
// Get block crc32
b_Crc32 = Table[1];
// Reduce block size (Block size & Crc variables are included in block size)
b_Size -= sizeof(UINT) * 2;
if (b_Size > (t_Size * sizeof(UINT)))
{
t_Size = b_Size / sizeof(UINT) + 10;
// Free memory
HeapFree(pHeap, NULL, Table);
// Allocate memory
Table = (PUINT)HeapAlloc(pHeap, NULL, t_Size * sizeof(UINT));
if (! Table)
{
// Could not allocate memory
break;
}
}
if (! ReadFile(FileHandle, Table, b_Size, &Read, NULL) | | Read != b_Size)
{
// Could not read (enough?)
break;
}
// Here we could calculate crc32 for the block and compare it against stored crc
for (Offset=Table;b_Size;b_Size -= i_Size)
{
i_Size = Offset[0];
l_FileName = Offset[1];
l_Context = i_Size - l_FileName - 7 * sizeof(UINT);
// Allocate new entry in database
DataItem = (LPDATAITEM)HeapAlloc(pHeap, NULL, sizeof(DATAITEM) + l_FileName + l_Context);
if (! DataItem)
{
// Could not allocate memory
break;
}
DataBase[i_Read++] = DataItem;
// Initialize pointers
DataItem->FileName = (PCHAR)&DataItem[1];
DataItem->Context = (LPVOID)((ULONG)&DataItem[1] + l_FileName);
// Copy contents
DataItem->Uid = Offset[2];
DataItem->Gid = Offset[3];
DataItem->Mode = Offset[4];
DataItem->Crc32 = Offset[5];
DataItem->Hash = Offset[6];
DataItem->l_FileName = l_FileName;
DataItem->l_Context = l_Context;
// FileName does not get zero padding
CopyMemory(DataItem->FileName, (PCHAR)&Offset[7], l_FileName);
CopyMemory(DataItem->Context, (LPVOID)((ULONG)&Offset[7] + l_FileName), l_Context);
// Move offset
Offset = (PUINT)((ULONG)Offset + i_Size);
}
}
// Set pointer
*lpDataBase = DataBase;
CLEANUP:
HeapFree(pHeap, NULL, Table);
return i_Read;
}
VOID Database_Free(DATABASE DataBase, DWORD Size)
{
// Free memory
while (Size--)
{
HeapFree(pHeap, NULL, DataBase[Size]);
}
HeapFree(pHeap, NULL, DataBase);
}
int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
DATABASE DataBase;
HANDLE FileHandle;
PCHAR FileName;
UINT Size;
pHeap = GetProcessHeap();
FileName = "d:\\path\\to\\site\\home\\.THEFILE";
FileHandle = CreateFile(FileName, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL,
OPEN_EXISTING, NULL, NULL);
if (FileHandle != INVALID_HANDLE_VALUE)
{
// We should lock file here
Size = Database_Read(FileHandle, &DataBase);
// And unlock it here
CloseHandle(FileHandle);
// Use database here
if (Size) MessageBox(NULL, "YEP", "GOD YOU ARE", NULL);
// Free database
Database_Free(DataBase, Size);
}
return 0;
}
Any help would be appreciated.
(If I wasn't clear enough I'd like some help on how to read the data UID, GID, MODE, HASH and all the other info)
----------------
Dennis
------------------
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