File Splitter

High-performance binary file splitter, I've written in 2009 with C# and C++.

⚠️ This code is legacy, not maintained and may have a lot of issues.

🌼 The main reason for publishing this project that it may be useful for someone to learn from, it has a lot of advanced concepts including Custom GDI+ Components, Threading, Memory Caching, Virtual Memory Mapping, and C++ Win32 Programming.

Requirments:

• .Net Framework 2.0
• Visual Studio 2010 or later
• Microsoft Windows SDK

Components:

1- MMH Split Project

Main C# application while handles reading source files and split the data and also joining it.

2- Q Join Project

C++ portable self-extractor, which will be included to join files into the original source file without the main application.

It has a very small memory footprint, and the join process handled in a separate thread, with the ability to detect missing files and read it on demand from different sources.

It can work also on Linux with wine.

All details about files to be joined are injected to Q Join executable it will be mapped and parsed into memory to get all details.

Mapping and extraction of stub binary data.

const HANDLE buff = 0;
HANDLE file = NULL;
DWORD buffer = 0;
char* namebuffer = new char[255];

GetModuleFileName(GetModuleHandle(0), LPCH(namebuffer), 255);
file = CreateFileA(namebuffer, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, buff);
SetFilePointer(file, realSize, 0,FILE_BEGIN);

unsigned int fSize = 0;
unsigned int stubSize = 0;
const bool fsResult = GetFileSizeEx(file, PLARGE_INTEGER(&fSize));
if (fsResult && fSize > realSize)
{
    stubSize = (fSize - realSize) + 1;
}

if (stubSize <= 0)
{
    return "";
}

const LPVOID memory = VirtualAlloc(0, stubSize, MEM_COMMIT, PAGE_READWRITE);
ReadFile(file, memory, stubSize, LPDWORD(&buffer),NULL);

TCHAR* pStub = new TCHAR[stubSize];
memcpy_s(pStub, stubSize, memory, stubSize);
VirtualFree(memory, 0, MEM_RELEASE);
CloseHandle(file);

License

MIT