Load an arbitrary file to memory using a combination of CreateFileW + ReadFile + HeapAlloc + HeapFree

win32-heap-alloc.cpp

BOOL GetFileBufferInMemory(
	LPCWSTR lpFileName, 
	LPVOID* pDestBuffer
) {
	HANDLE FileHandle = CreateFileW(lpFileName, GENERIC_READ, NULL, NULL, OPEN_EXISTING, NULL, NULL);

	if (FileHandle == INVALID_HANDLE_VALUE) {
		printf_s("CreateFileW failed to retrieve the file handle.");
		return FALSE;
	}

	DWORD FileSize = GetFileSize(FileHandle, NULL);

	if (FileSize == INVALID_FILE_SIZE) {
		printf_s("GetFileSize failed to retrieve the file size.");
		return FALSE;
	}

	LPVOID pBuffer = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, FileSize);

	if (pBuffer == NULL) {
		printf_s("HeapAlloc failed to allocate in-memory page block.");
		return FALSE;
	}
	
	DWORD TotalReadBytes = 0;
	BOOL Status = ReadFile(FileHandle, pBuffer, FileSize, &TotalReadBytes, NULL);

	if ((Status == FALSE) || (TotalReadBytes != FileSize)) {
		HeapFree(GetProcessHeap(), NULL, pBuffer);
		return FALSE;
	}

	*pDestBuffer = pBuffer;
	
	return CloseHandle(FileHandle);
}

BOOL ReleaseFileBufferInMemory(LPVOID pDestBuffer) {
	return HeapFree(GetProcessHeap(), NULL, pDestBuffer);
}