segatools/nu/nvram.c

82 lines
1.6 KiB
C
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#include <windows.h>
#include <assert.h>
#include <stddef.h>
2018-11-23 19:37:42 +00:00
#include <stdint.h>
#include "util/dprintf.h"
#include "nu/nvram.h"
HRESULT nvram_open_file(HANDLE *out, wchar_t *path, size_t size)
{
LARGE_INTEGER cur_size;
LARGE_INTEGER pos;
HANDLE file;
HRESULT hr;
BOOL ok;
assert(out != NULL);
assert(path != NULL);
*out = NULL;
file = CreateFileW(
path,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ,
NULL,
OPEN_ALWAYS,
FILE_ATTRIBUTE_NORMAL,
NULL);
if (file == INVALID_HANDLE_VALUE) {
hr = HRESULT_FROM_WIN32(GetLastError());
dprintf("%S: Error opening backing store: %x\n", path, (int) hr);
goto end;
}
ok = GetFileSizeEx(file, &cur_size);
if (!ok) {
hr = HRESULT_FROM_WIN32(GetLastError());
dprintf("%S: GetFileSizeEx failed: %x\n", path, (int) hr);
goto end;
}
if (cur_size.QuadPart != (uint64_t) size) {
pos.QuadPart = (uint64_t) size;
ok = SetFilePointerEx(file, pos, NULL, FILE_BEGIN);
if (!ok) {
hr = HRESULT_FROM_WIN32(GetLastError());
dprintf("%S: SetFilePointerEx failed: %x\n", path, (int) hr);
goto end;
}
ok = SetEndOfFile(file);
if (!ok) {
hr = HRESULT_FROM_WIN32(GetLastError());
dprintf("%S: SetEndOfFile failed: %x\n", path, (int) hr);
goto end;
}
}
*out = file;
file = INVALID_HANDLE_VALUE;
hr = S_OK;
end:
if (file != INVALID_HANDLE_VALUE) {
CloseHandle(file);
}
return hr;
}