Method substring

src/common/CharSet.cpp:143–169

ULONG FixedWidthCharSet::substring(const ULONG srcLen, const UCHAR* src, const ULONG dstLen, UCHAR* dst,
	const ULONG startPos, const ULONG len) const
{
	ULONG result;

	if (getStruct()->charset_fn_substring)
		result = getStruct()->charset_fn_substring(getStruct(), srcLen, src, dstLen, dst, startPos, len);
	else
	{
		fb_assert(src != NULL && dst != NULL);

		result = MIN(srcLen / minBytesPerChar() - startPos, len) * minBytesPerChar();

		if (dstLen < result)
			result = INTL_BAD_STR_LENGTH;
		else if (startPos * minBytesPerChar() > srcLen)
			result = 0;
		else
			memcpy(dst, src + startPos * minBytesPerChar(), result);
	}

	if (result == INTL_BAD_STR_LENGTH)
		status_exception::raise(Arg::Gds(isc_arith_except) << Arg::Gds(isc_string_truncation) <<
			Arg::Gds(isc_trunc_limits) << Arg::Num(dstLen) << Arg::Num(len));

	return result;
}


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