reactos/sdk/lib/ucrt/mbstring/mbsnset_s.inl

132 lines
3.3 KiB
C++

/***
*mbsnset_s.inl - general implementation of _mbsnset_s and _mbsnbset_s
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
*Purpose:
* This file contains the general algorithm for _mbsnset_s and _mbsnbset_s.
*
****/
errno_t __cdecl _FUNC_NAME(unsigned char *_Dst, size_t _SizeInBytes, unsigned int _Value, size_t _COUNT, _LOCALE_ARG_DECL)
{
int mbcs_error = 0;
unsigned char *p;
size_t available;
unsigned char highval, lowval;
int mblead = 0;
/* validation section */
if (_COUNT == 0 && _Dst == nullptr && _SizeInBytes == 0)
{
/* this case is allowed; nothing to do */
_RETURN_NO_ERROR;
}
_VALIDATE_STRING(_Dst, _SizeInBytes);
_LOCALE_UPDATE;
if (_LOCALE_SHORTCUT_TEST)
{
return _strnset_s((char *)_Dst, _SizeInBytes, (int)_Value, _COUNT);
}
p = _Dst;
available = _SizeInBytes;
highval = (unsigned char)(_Value >> 8);
lowval = (unsigned char)(_Value & 0x00ff);
/* ensure _Value is a valid mbchar */
if ((highval != 0 && (lowval == 0 || !_ISMBBLEAD(highval))) ||
(highval == 0 && _ISMBBLEAD(lowval)))
{
_RESET_STRING(_Dst, _SizeInBytes);
_RETURN_MBCS_ERROR;
}
if (highval != 0)
{
#if _COUNT_IN_BYTES
/* if _COUNT is odd, make it even subtracting 1 */
/* divide _COUNT by 2 to have a count in chars instead of bytes */
if ((_COUNT & 1) == 1)
{
--_COUNT;
mbcs_error = 1;
}
_COUNT = _COUNT / 2;
#endif /* _COUNT_IN_BYTES */
while (*p != 0 && _COUNT > 0 && --available > 0)
{
if (p[1] == 0)
{
/* do not orphan leadbyte */
*p = 0;
++available;
mbcs_error = 1;
break;
}
/* track the mblead status in the original string */
mblead = mblead ? 0 : _ISMBBLEAD(*p);
*p++ = highval;
if (--available == 0)
{
break;
}
mblead = mblead ? 0 : _ISMBBLEAD(*p);
*p++ = lowval;
--_COUNT;
}
}
else
{
while (*p != 0 && _COUNT > 0 && --available > 0)
{
/* track the mblead status in the original string */
mblead = mblead ? 0 : _ISMBBLEAD(*p);
*p++ = lowval;
--_COUNT;
}
}
/* if the last written byte overlapps a leadbyte,
* copy a space over the corresponding trailbyte */
if (_COUNT == 0 && mblead && *p != 0 && --available > 0)
{
mbcs_error = 1;
if (p[1] == 0)
{
/* special case: if the space would be followed by 0, just put a 0 */
*p = 0;
++available;
}
else
{
*p++ = ' ';
}
}
if (_COUNT == 0)
{
/* ensure the string is null-terminated */
while (*p != 0 && --available > 0)
{
++p;
}
}
if (available == 0)
{
_RESET_STRING(_Dst, _SizeInBytes);
_RETURN_DEST_NOT_NULL_TERMINATED(_Dst, _SizeInBytes);
}
_FILL_STRING(_Dst, _SizeInBytes, _SizeInBytes - available + 1);
if (mbcs_error)
{
_RETURN_MBCS_ERROR;
}
else
{
_RETURN_NO_ERROR;
}
}