Function CVT_get_int128

src/common/cvt.cpp:3142–3293

Int128 CVT_get_int128(const dsc* desc, SSHORT scale, DecimalStatus decSt, ErrorFunction err)
{
/**************************************
 *
 *      C V T _ g e t _ d e c 1 2 8
 *
 **************************************
 *
 * Functional description
 *      Convert something arbitrary to 128 bit integer.
 *
 **************************************/
	VaryStr<1024> buffer;			// represents unreasonably long decfloat literal in ASCII
	Int128 int128;
	Decimal128 tmp;
	double d, eps;

	static const double I128_MIN_dbl = -1.701411834604692e+38;
	static const double I128_MAX_dbl =  1.701411834604692e+38;
	static const CDecimal128 I128_MIN_dcft("-1.701411834604692317316873037158841E+38", decSt);
	static const CDecimal128 I128_MAX_dcft("1.701411834604692317316873037158841E+38", decSt);
	static const CDecimal128 DecFlt_05("0.5", decSt);

	// adjust exact numeric values to same scaling
	if (DTYPE_IS_EXACT(desc->dsc_dtype))
		scale -= desc->dsc_scale;

	const char* p = reinterpret_cast<char*>(desc->dsc_address);

	try
	{
		switch (desc->dsc_dtype)
		{
		case dtype_short:
			int128.set(SLONG(*(SSHORT*) p), scale);
			break;

		case dtype_long:
			int128.set(*(SLONG*) p, scale);
			break;

		case dtype_quad:
			int128.set(CVT_get_int64(desc, 0, decSt, err), scale);
			break;

		case dtype_int64:
			int128.set(*(SINT64*) p, scale);
			break;

		case dtype_varying:
		case dtype_cstring:
		case dtype_text:
			{
				USHORT length =
					CVT_make_string(desc, ttype_ascii, &p, &buffer, sizeof(buffer), decSt, err);
				scale -= CVT_decompose(p, length, &int128, err);
				int128.setScale(scale);
			}