Пример #1
0
/**
 * @return <0 if error
 */
TDS_INT
tds_numeric_to_string(const TDS_NUMERIC * numeric, char *s)
{
	const unsigned char *number;

	unsigned int packet[sizeof(numeric->array) / 2];
	unsigned int *pnum, *packet_start;
	unsigned int *const packet_end = packet + TDS_VECTOR_SIZE(packet);

	unsigned int packet10k[(MAXPRECISION + 3) / 4];
	unsigned int *p;

	int num_bytes;
	unsigned int remainder, n, i, m;

	/* a bit of debug */
#if ENABLE_EXTRA_CHECKS
	memset(packet, 0x55, sizeof(packet));
	memset(packet10k, 0x55, sizeof(packet10k));
#endif

	if (numeric->precision < 1 || numeric->precision > MAXPRECISION || numeric->scale > numeric->precision)
		return TDS_CONVERT_FAIL;

	/* set sign */
	if (numeric->array[0] == 1)
		*s++ = '-';

	/* put number in a 16bit array */
	number = numeric->array;
	num_bytes = tds_numeric_bytes_per_prec[numeric->precision];

	n = num_bytes - 1;
	pnum = packet_end;
	for (; n > 1; n -= 2)
		*--pnum = TDS_GET_UA2BE(&number[n - 1]);
	if (n == 1)
		*--pnum = number[n];
	while (!*pnum) {
		++pnum;
		if (pnum == packet_end) {
			*s++ = '0';
			if (numeric->scale) {
				*s++ = '.';
				i = numeric->scale;
				do {
					*s++ = '0';
				} while (--i);
			}
			*s = 0;
			return 1;
		}
	}
	packet_start = pnum;

	/* transform 2^16 base number in 10^4 base number */
	for (p = packet10k + TDS_VECTOR_SIZE(packet10k); packet_start != packet_end;) {
		pnum = packet_start;
		n = *pnum;
		remainder = n % 10000u;
		if (!(*pnum++ = (n / 10000u)))
			packet_start = pnum;
		for (; pnum != packet_end; ++pnum) {
			n = remainder * (256u * 256u) + *pnum;
			remainder = n % 10000u;
			*pnum = n / 10000u;
		}
		*--p = remainder;
	}

	/* transform to 10 base number and output */
	i = 4 * (unsigned int)((packet10k + TDS_VECTOR_SIZE(packet10k)) - p);	/* current digit */
	/* skip leading zeroes */
	n = 1000;
	remainder = *p;
	while (remainder < n)
		n /= 10, --i;
	if (i <= numeric->scale) {
		*s++ = '0';
		*s++ = '.';
		m = i;
		while (m < numeric->scale)
			*s++ = '0', ++m;
	}
	for (;;) {
		*s++ = (remainder / n) + '0';
		--i;
		remainder %= n;
		n /= 10;
		if (!n) {
			n = 1000;
			if (++p == packet10k + TDS_VECTOR_SIZE(packet10k))
				break;
			remainder = *p;
		}
		if (i == numeric->scale)
			*s++ = '.';
	}
	*s = 0;

	return 1;
}
Пример #2
0
TDS_INT
tds_numeric_change_prec_scale(TDS_NUMERIC * numeric, unsigned char new_prec, unsigned char new_scale)
{
	static const TDS_WORD factors[] = {
		1, 10, 100, 1000, 10000,
#ifdef HAVE_INT64
		100000, 1000000, 10000000, 100000000, 1000000000
#endif
	};

	TDS_WORD packet[(sizeof(numeric->array) - 1) / sizeof(TDS_WORD)];

	unsigned int i, packet_len;
	int scale_diff, bytes;

	if (numeric->precision < 1 || numeric->precision > 77 || numeric->scale > numeric->precision)
		return TDS_CONVERT_FAIL;

	if (new_prec < 1 || new_prec > 77 || new_scale > new_prec)
		return TDS_CONVERT_FAIL;

	scale_diff = new_scale - numeric->scale;
	if (scale_diff == 0 && new_prec >= numeric->precision) {
		i = tds_numeric_bytes_per_prec[new_prec] - tds_numeric_bytes_per_prec[numeric->precision];
		if (i > 0) {
			memmove(numeric->array + 1 + i, numeric->array + 1, sizeof(numeric->array) - 1 - i);
			memset(numeric->array + 1, 0, i);
		}
		numeric->precision = new_prec;
		return sizeof(TDS_NUMERIC);
	}

	/* package number */
	bytes = tds_numeric_bytes_per_prec[numeric->precision] - 1;
	i = 0;
	do {
		/*
		 * note that if bytes are smaller we have a small buffer
		 * overflow in numeric->array however is not a problem
		 * cause overflow occurs in numeric and number is fixed below
		 */
#ifndef HAVE_INT64
		packet[i] = TDS_GET_UA2BE(&numeric->array[bytes-1]);
#else
		packet[i] = TDS_GET_UA4BE(&numeric->array[bytes-3]);
#endif
		++i;
	} while ( (bytes -= sizeof(TDS_WORD)) > 0);
	/* fix last packet */
	if (bytes < 0)
		packet[i-1] &= 0xffffffffu >> (8 * -bytes);
	while (i > 1 && packet[i-1] == 0)
		--i;
	packet_len = i;

	if (scale_diff >= 0) {
		/* check overflow before multiply */
		if (tds_packet_check_overflow(packet, packet_len, new_prec - scale_diff))
			return TDS_CONVERT_OVERFLOW;

		if (scale_diff == 0) {
			i = tds_numeric_bytes_per_prec[numeric->precision] - tds_numeric_bytes_per_prec[new_prec];
			if (i > 0)
				memmove(numeric->array + 1, numeric->array + 1 + i, sizeof(numeric->array) - 1 - i);
			numeric->precision = new_prec;
			return sizeof(TDS_NUMERIC);
		}

		/* multiply */
		do {
			/* multiply by at maximun TDS_WORD_DDIGIT */
			unsigned int n = scale_diff > TDS_WORD_DDIGIT ? TDS_WORD_DDIGIT : scale_diff;
			TDS_WORD factor = factors[n];
			TDS_WORD carry = 0;
			scale_diff -= n; 
			for (i = 0; i < packet_len; ++i) {
				TDS_DWORD n = packet[i] * ((TDS_DWORD) factor) + carry;
				packet[i] = (TDS_WORD) n;
				carry = n >> (8 * sizeof(TDS_WORD));
			}
			/* here we can expand number safely cause we know that it can't overflow */
			if (carry)
				packet[packet_len++] = carry;
		} while (scale_diff > 0);
	} else {
		/* check overflow */
		if (new_prec - scale_diff < numeric->precision)