int ObNumber::div(const ObNumber &other, ObNumber &res) const
{
int ret = OB_SUCCESS;
res.set_zero();
if (other.is_zero())
{
jlog(WARNING, "divisor is zero");
ret = JD_DIVISION_BY_ZERO;
}
else if (!this->is_zero())
{
res.vscale_ = QUOTIENT_SCALE;
ObNumber dividend = *this;
ObNumber divisor = other;
ObNumber remainder;
bool res_is_neg = false;
if (dividend.is_negative())
{
negate(dividend, dividend);
res_is_neg = true;
}
if (dividend.vscale_ > DOUBLE_PRECISION_NDIGITS)
{
dividend.round_fraction_part(DOUBLE_PRECISION_NDIGITS);
}
if (divisor.vscale_ > SINGLE_PRECISION_NDIGITS)
{
divisor.round_fraction_part(SINGLE_PRECISION_NDIGITS);
}
if (dividend.vscale_ < divisor.vscale_
|| res.vscale_ > dividend.vscale_ - divisor.vscale_)
{
if (OB_SUCCESS != (ret = dividend.left_shift(static_cast<int8_t> (res.vscale_ + divisor.vscale_ - dividend.vscale_), true)))
{
jlog(WARNING, "left shift overflow, err=%d res_vscale=%hhd other_vscale=%hhd this_vscale=%hhd",
ret, res.vscale_, divisor.vscale_, dividend.vscale_);
}
}
if (OB_LIKELY(OB_SUCCESS == ret))
{
if (divisor.is_negative())
{
negate(divisor, divisor);
res_is_neg = !res_is_neg;
}
divisor.remove_leading_zeroes_unsigned();
div_words(dividend, divisor, res, remainder);
if (OB_UNLIKELY(res_is_neg))
{
negate(res, res);
}
res.remove_leading_zeroes();
}
}
return ret;
}
int ObNumber::cast_to_int64(int64_t &i64) const
{
int ret = OB_SUCCESS;
i64 = 0;
bool is_neg = is_negative();
ObNumber pos_clone = *this;
if (is_neg)
{
negate(*this, pos_clone);
}
ObNumber remainder;
int vscale = vscale_;
int digits[DOUBLE_PRECISION_NDIGITS];
int digit_idx = DOUBLE_PRECISION_NDIGITS - 1;
while (!pos_clone.is_zero())
{
div_uint32(pos_clone, 10, pos_clone, remainder);
if (vscale > 0)
{
vscale--;
}
else
{
OB_ASSERT(digit_idx >= 0);
if (remainder.is_zero())
{
digits[digit_idx--] = 0;
}
else
{
OB_ASSERT(1 == remainder.nwords_);
OB_ASSERT(remainder.words_[0] < 10 && remainder.words_[0] > 0);
digits[digit_idx--] = remainder.words_[0];
}
} // end while
}
OB_ASSERT(digit_idx >= -1);
for (int i = digit_idx + 1; i < DOUBLE_PRECISION_NDIGITS; ++i)
{
i64 = i64 * 10 + digits[i];
}
if (is_neg)
{
i64 = -i64;
}
return ret;
}
bool ObObj::is_true() const
{
bool ret = false;
switch (get_type())
{
case ObBoolType:
ret = value_.bool_val;
break;
case ObVarcharType:
ret = (val_len_ > 0);
break;
case ObIntType:
ret = (value_.int_val != 0);
break;
case ObDecimalType:
{
ObNumber dec;
bool is_add = false;
if (OB_SUCCESS == get_decimal(dec, is_add))
{
ret = !dec.is_zero();
}
break;
}
case ObFloatType:
ret = (fabsf(value_.float_val) > FLOAT_EPSINON);
break;
case ObDoubleType:
ret = (fabs(value_.double_val) > DOUBLE_EPSINON);
break;
case ObDateTimeType:
case ObPreciseDateTimeType:
case ObCreateTimeType:
case ObModifyTimeType:
{
int64_t ts1 = 0;
get_timestamp(ts1);
ret = (0 != ts1);
break;
}
default:
break;
}
return ret;
}
int ObNumber::compare(const ObNumber &other) const
{
int ret = 0;
ObNumber res;
if (OB_SUCCESS != this->sub(other, res))
{
// return 0 even if error occur
}
else if (res.is_negative())
{
ret = -1;
}
else if (!res.is_zero())
{
ret = 1;
}
return ret;
}
int ObNumber::mul(const ObNumber &other, ObNumber &res) const
{
int ret = OB_SUCCESS;
res.set_zero();
if (!this->is_zero() && !other.is_zero())
{
ObNumber multiplicand = *this;
ObNumber multiplier = other;
bool res_is_neg = false;
if (multiplicand.is_negative())
{
negate(multiplicand, multiplicand);
res_is_neg = true;
}
if (multiplier.is_negative())
{
negate(multiplier, multiplier);
res_is_neg = !res_is_neg;
}
if (multiplicand.vscale_ > SINGLE_PRECISION_NDIGITS)
{
multiplicand.round_fraction_part(SINGLE_PRECISION_NDIGITS);
}
if (multiplier.vscale_ > SINGLE_PRECISION_NDIGITS)
{
multiplier.round_fraction_part(SINGLE_PRECISION_NDIGITS);
}
res.vscale_ = static_cast<int8_t> (multiplicand.vscale_ + multiplier.vscale_);
ret = mul_words(multiplicand, multiplier, res);
res.remove_leading_zeroes();
if (res_is_neg)
{
negate(res, res);
}
}
return ret;
}
void ObNumber::knuth_div_unsigned(const uint32_t *dividend,
const ObNumber &divisor,
ObNumber "ient, int8_t qidx, ObNumber &remainder)
{
OB_ASSERT(divisor.words_[divisor.nwords_ - 1] >= HALF_BASE); // (BASE ^ divisor_n)/2 <= divisor
OB_ASSERT(0 <= qidx && qidx < MAX_NWORDS);
ObNumber cdividend;
cdividend.nwords_ = static_cast<int8_t> (divisor.nwords_ + 1);
for (int8_t i = 0; i < cdividend.nwords_; ++i)
{
cdividend.words_[i] = dividend[i];
}
ObNumber base;
base.from(BASE);
ObNumber p;
mul_words(base, divisor, p);
p.remove_leading_zeroes_unsigned();
int cmp = compare_words_unsigned(cdividend, p);
if (cmp >= 0)
{
sub_words_unsigned(cdividend, p, cdividend);
knuth_div_unsigned(cdividend.words_, divisor, quotient, qidx, remainder); // recursively called at most once
quotient.words_[qidx + 1] = 1;
}
else
{
int8_t n = divisor.nwords_;
uint64_t q = (UBASE * dividend[n] + dividend[n - 1]) / divisor.words_[n - 1];
if (q >= UBASE)
{
q = UBASE - 1;
}
ObNumber Q;
Q.from(q);
ObNumber T;
mul_words(Q, divisor, T);
T.remove_leading_zeroes_unsigned();
for (int i = 0; i < 2; ++i)
{
cmp = compare_words_unsigned(T, cdividend);
if (cmp > 0)
{
Q.from(--q);
sub_words_unsigned(T, divisor, T);
}
else
{
break;
}
} // end for
if (Q.nwords_ == 1)
{
quotient.words_[qidx] = Q.words_[0];
}
else
{
OB_ASSERT(Q.is_zero());
quotient.words_[qidx] = 0;
}
sub_words_unsigned(cdividend, T, remainder);
}
}
int64_t ObNumber::to_string(char* buf, const int64_t buf_len) const
{
int64_t pos = 0;
OB_ASSERT(nwords_ <= MAX_NWORDS);
OB_ASSERT(nwords_ > 0);
char inner_buf[MAX_PRINTABLE_SIZE];
ObNumber clone;
bool is_neg = is_negative();
if (is_neg)
{
negate(*this, clone);
}
else
{
clone = *this;
}
ObNumber remainder;
int i = MAX_PRINTABLE_SIZE;
while (!clone.is_zero())
{
div_uint32(clone, 10, clone, remainder);
if (remainder.is_zero())
{
inner_buf[--i] = '0';
}
else
{
OB_ASSERT(1 == remainder.nwords_);
OB_ASSERT(remainder.words_[0] < 10 && remainder.words_[0] > 0);
inner_buf[--i] = static_cast<char> ('0' + remainder.words_[0]);
}
OB_ASSERT(0 < i);
} // end while
int64_t dec_digits_num = MAX_PRINTABLE_SIZE - i;
if (0 == dec_digits_num)
{
databuff_printf(buf, buf_len, pos, "0");
}
else
{
if (is_neg)
{
databuff_printf(buf, buf_len, pos, "-");
}
if (clone.vscale_ >= dec_digits_num)
{
// 0.0...0xxx
databuff_printf(buf, buf_len, pos, "0.");
for (int j = 0; j < clone.vscale_ - dec_digits_num; ++j)
{
databuff_printf(buf, buf_len, pos, "0");
}
if (NULL != buf && 0 <= pos && dec_digits_num < buf_len - pos)
{
memcpy(buf + pos, inner_buf + i, dec_digits_num);
pos += dec_digits_num;
buf[pos] = '\0';
}
}
else
{
if (NULL != buf && 0 <= pos && dec_digits_num - clone.vscale_ < buf_len - pos)
{
memcpy(buf + pos, inner_buf + i, dec_digits_num - clone.vscale_); // digits before the point
pos += dec_digits_num - clone.vscale_;
}
if (clone.vscale_ > 0)
{
if (NULL != buf && 0 <= pos && 1 + clone.vscale_ < buf_len - pos)
{
buf[pos++] = '.';
memcpy(buf + pos, inner_buf + i + dec_digits_num - clone.vscale_, clone.vscale_); // digits after the point
pos += clone.vscale_;
}
}
if (NULL != buf && 0 <= pos && 0 < buf_len - pos)
{
buf[pos] = '\0';
}
}
}
OB_ASSERT(pos <= buf_len);
return pos;
}
inline void ObNumber::div_words(const ObNumber ÷nd, const ObNumber &divisor, ObNumber "ient, ObNumber &remainder)
{
OB_ASSERT(!dividend.is_zero());
OB_ASSERT(!divisor.is_zero());
OB_ASSERT(0 < dividend.nwords_ && dividend.nwords_ <= MAX_NWORDS);
OB_ASSERT(0 < divisor.nwords_ && divisor.nwords_ <= MAX_NWORDS);
if (1 == divisor.nwords_)
{
// fast algorithm
div_uint32(dividend, divisor.words_[0], quotient, remainder);
}
else
{
// Knuth's algorithm, Volumn 2, Section 4.3, Page 235
ObNumber cdivisor;
ObNumber cdividend;
if (divisor.words_[divisor.nwords_ - 1] < HALF_BASE)
{
// make sure (BASE ^ n)/2 <= divisor
uint32_t factor = static_cast<uint32_t> (BASE / (divisor.words_[divisor.nwords_ - 1] + 1));
mul_uint32(divisor, factor, cdivisor, true);
mul_uint32(dividend, factor, cdividend, true);
OB_ASSERT(cdivisor.words_[cdivisor.nwords_ - 1] >= HALF_BASE);
}
else
{
cdividend = dividend;
cdivisor = divisor;
}
if (cdividend.nwords_ < cdivisor.nwords_) // include the case when dividend is zero
{
quotient.set_zero();
remainder = dividend;
}
else if (cdividend.nwords_ == cdivisor.nwords_)
{
int cmp = compare_words_unsigned(cdividend, cdivisor);
if (cmp < 0)
{
quotient.set_zero();
remainder = dividend;
}
else
{
quotient.nwords_ = 1;
quotient.words_[0] = 1;
sub_words_unsigned(cdividend, cdivisor, remainder);
}
}
else // dividend.nwords_ >= 1 + divosor.nwords_
{
quotient.nwords_ = static_cast<int8_t> (cdividend.nwords_ - cdivisor.nwords_ + 1);
memset(quotient.words_, 0, sizeof (quotient.words_));
for (int8_t i = static_cast<int8_t> (cdividend.nwords_ - cdivisor.nwords_ - 1); i >= 0; --i)
{
knuth_div_unsigned(&cdividend.words_[i], cdivisor, quotient, i, remainder);
for (int8_t j = 0; j < cdivisor.nwords_; ++j)
{
cdividend.words_[i + j] = remainder.words_[j];
}
}
}
}
if (quotient.nwords_ > 0
&& static_cast<int64_t> (quotient.words_[quotient.nwords_ - 1]) >= HALF_BASE)
{
quotient.words_[quotient.nwords_++] = 0; // quotient is always positive
}
if (remainder.nwords_ > 0
&& static_cast<int64_t> (remainder.words_[remainder.nwords_ - 1]) >= HALF_BASE)
{
remainder.words_[remainder.nwords_++] = 0; // remainder is always positive
}
}
