1 files changed, 423 insertions, 0 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/primitive/decimal.go b/vendor/go.mongodb.org/mongo-driver/bson/primitive/decimal.go
new file mode 100644
index 000000000..ba7c9112e
--- /dev/null
+++ b/vendor/go.mongodb.org/mongo-driver/bson/primitive/decimal.go
@@ -0,0 +1,423 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+//
+// Based on gopkg.in/mgo.v2/bson by Gustavo Niemeyer
+// See THIRD-PARTY-NOTICES for original license terms.
+
+package primitive
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math/big"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// These constants are the maximum and minimum values for the exponent field in a decimal128 value.
+const (
+	MaxDecimal128Exp = 6111
+	MinDecimal128Exp = -6176
+)
+
+// These errors are returned when an invalid value is parsed as a big.Int.
+var (
+	ErrParseNaN    = errors.New("cannot parse NaN as a *big.Int")
+	ErrParseInf    = errors.New("cannot parse Infinity as a *big.Int")
+	ErrParseNegInf = errors.New("cannot parse -Infinity as a *big.Int")
+)
+
+// Decimal128 holds decimal128 BSON values.
+type Decimal128 struct {
+	h, l uint64
+}
+
+// NewDecimal128 creates a Decimal128 using the provide high and low uint64s.
+func NewDecimal128(h, l uint64) Decimal128 {
+	return Decimal128{h: h, l: l}
+}
+
+// GetBytes returns the underlying bytes of the BSON decimal value as two uint64 values. The first
+// contains the most first 8 bytes of the value and the second contains the latter.
+func (d Decimal128) GetBytes() (uint64, uint64) {
+	return d.h, d.l
+}
+
+// String returns a string representation of the decimal value.
+func (d Decimal128) String() string {
+	var posSign int      // positive sign
+	var exp int          // exponent
+	var high, low uint64 // significand high/low
+
+	if d.h>>63&1 == 0 {
+		posSign = 1
+	}
+
+	switch d.h >> 58 & (1<<5 - 1) {
+	case 0x1F:
+		return "NaN"
+	case 0x1E:
+		return "-Infinity"[posSign:]
+	}
+
+	low = d.l
+	if d.h>>61&3 == 3 {
+		// Bits: 1*sign 2*ignored 14*exponent 111*significand.
+		// Implicit 0b100 prefix in significand.
+		exp = int(d.h >> 47 & (1<<14 - 1))
+		//high = 4<<47 | d.h&(1<<47-1)
+		// Spec says all of these values are out of range.
+		high, low = 0, 0
+	} else {
+		// Bits: 1*sign 14*exponent 113*significand
+		exp = int(d.h >> 49 & (1<<14 - 1))
+		high = d.h & (1<<49 - 1)
+	}
+	exp += MinDecimal128Exp
+
+	// Would be handled by the logic below, but that's trivial and common.
+	if high == 0 && low == 0 && exp == 0 {
+		return "-0"[posSign:]
+	}
+
+	var repr [48]byte // Loop 5 times over 9 digits plus dot, negative sign, and leading zero.
+	var last = len(repr)
+	var i = len(repr)
+	var dot = len(repr) + exp
+	var rem uint32
+Loop:
+	for d9 := 0; d9 < 5; d9++ {
+		high, low, rem = divmod(high, low, 1e9)
+		for d1 := 0; d1 < 9; d1++ {
+			// Handle "-0.0", "0.00123400", "-1.00E-6", "1.050E+3", etc.
+			if i < len(repr) && (dot == i || low == 0 && high == 0 && rem > 0 && rem < 10 && (dot < i-6 || exp > 0)) {
+				exp += len(repr) - i
+				i--
+				repr[i] = '.'
+				last = i - 1
+				dot = len(repr) // Unmark.
+			}
+			c := '0' + byte(rem%10)
+			rem /= 10
+			i--
+			repr[i] = c
+			// Handle "0E+3", "1E+3", etc.
+			if low == 0 && high == 0 && rem == 0 && i == len(repr)-1 && (dot < i-5 || exp > 0) {
+				last = i
+				break Loop
+			}
+			if c != '0' {
+				last = i
+			}
+			// Break early. Works without it, but why.
+			if dot > i && low == 0 && high == 0 && rem == 0 {
+				break Loop
+			}
+		}
+	}
+	repr[last-1] = '-'
+	last--
+
+	if exp > 0 {
+		return string(repr[last+posSign:]) + "E+" + strconv.Itoa(exp)
+	}
+	if exp < 0 {
+		return string(repr[last+posSign:]) + "E" + strconv.Itoa(exp)
+	}
+	return string(repr[last+posSign:])
+}
+
+// BigInt returns significand as big.Int and exponent, bi * 10 ^ exp.
+func (d Decimal128) BigInt() (*big.Int, int, error) {
+	high, low := d.GetBytes()
+	posSign := high>>63&1 == 0 // positive sign
+
+	switch high >> 58 & (1<<5 - 1) {
+	case 0x1F:
+		return nil, 0, ErrParseNaN
+	case 0x1E:
+		if posSign {
+			return nil, 0, ErrParseInf
+		}
+		return nil, 0, ErrParseNegInf
+	}
+
+	var exp int
+	if high>>61&3 == 3 {
+		// Bits: 1*sign 2*ignored 14*exponent 111*significand.
+		// Implicit 0b100 prefix in significand.
+		exp = int(high >> 47 & (1<<14 - 1))
+		//high = 4<<47 | d.h&(1<<47-1)
+		// Spec says all of these values are out of range.
+		high, low = 0, 0
+	} else {
+		// Bits: 1*sign 14*exponent 113*significand
+		exp = int(high >> 49 & (1<<14 - 1))
+		high = high & (1<<49 - 1)
+	}
+	exp += MinDecimal128Exp
+
+	// Would be handled by the logic below, but that's trivial and common.
+	if high == 0 && low == 0 && exp == 0 {
+		if posSign {
+			return new(big.Int), 0, nil
+		}
+		return new(big.Int), 0, nil
+	}
+
+	bi := big.NewInt(0)
+	const host32bit = ^uint(0)>>32 == 0
+	if host32bit {
+		bi.SetBits([]big.Word{big.Word(low), big.Word(low >> 32), big.Word(high), big.Word(high >> 32)})
+	} else {
+		bi.SetBits([]big.Word{big.Word(low), big.Word(high)})
+	}
+
+	if !posSign {
+		return bi.Neg(bi), exp, nil
+	}
+	return bi, exp, nil
+}
+
+// IsNaN returns whether d is NaN.
+func (d Decimal128) IsNaN() bool {
+	return d.h>>58&(1<<5-1) == 0x1F
+}
+
+// IsInf returns:
+//
+//	+1 d == Infinity
+//	 0 other case
+//	-1 d == -Infinity
+func (d Decimal128) IsInf() int {
+	if d.h>>58&(1<<5-1) != 0x1E {
+		return 0
+	}
+
+	if d.h>>63&1 == 0 {
+		return 1
+	}
+	return -1
+}
+
+// IsZero returns true if d is the empty Decimal128.
+func (d Decimal128) IsZero() bool {
+	return d.h == 0 && d.l == 0
+}
+
+// MarshalJSON returns Decimal128 as a string.
+func (d Decimal128) MarshalJSON() ([]byte, error) {
+	return json.Marshal(d.String())
+}
+
+// UnmarshalJSON creates a primitive.Decimal128 from a JSON string, an extended JSON $numberDecimal value, or the string
+// "null". If b is a JSON string or extended JSON value, d will have the value of that string, and if b is "null", d will
+// be unchanged.
+func (d *Decimal128) UnmarshalJSON(b []byte) error {
+	// Ignore "null" to keep parity with the standard library. Decoding a JSON null into a non-pointer Decimal128 field
+	// will leave the field unchanged. For pointer values, encoding/json will set the pointer to nil and will not
+	// enter the UnmarshalJSON hook.
+	if string(b) == "null" {
+		return nil
+	}
+
+	var res interface{}
+	err := json.Unmarshal(b, &res)
+	if err != nil {
+		return err
+	}
+	str, ok := res.(string)
+
+	// Extended JSON
+	if !ok {
+		m, ok := res.(map[string]interface{})
+		if !ok {
+			return errors.New("not an extended JSON Decimal128: expected document")
+		}
+		d128, ok := m["$numberDecimal"]
+		if !ok {
+			return errors.New("not an extended JSON Decimal128: expected key $numberDecimal")
+		}
+		str, ok = d128.(string)
+		if !ok {
+			return errors.New("not an extended JSON Decimal128: expected decimal to be string")
+		}
+	}
+
+	*d, err = ParseDecimal128(str)
+	return err
+}
+
+func divmod(h, l uint64, div uint32) (qh, ql uint64, rem uint32) {
+	div64 := uint64(div)
+	a := h >> 32
+	aq := a / div64
+	ar := a % div64
+	b := ar<<32 + h&(1<<32-1)
+	bq := b / div64
+	br := b % div64
+	c := br<<32 + l>>32
+	cq := c / div64
+	cr := c % div64
+	d := cr<<32 + l&(1<<32-1)
+	dq := d / div64
+	dr := d % div64
+	return (aq<<32 | bq), (cq<<32 | dq), uint32(dr)
+}
+
+var dNaN = Decimal128{0x1F << 58, 0}
+var dPosInf = Decimal128{0x1E << 58, 0}
+var dNegInf = Decimal128{0x3E << 58, 0}
+
+func dErr(s string) (Decimal128, error) {
+	return dNaN, fmt.Errorf("cannot parse %q as a decimal128", s)
+}
+
+// match scientific notation number, example -10.15e-18
+var normalNumber = regexp.MustCompile(`^(?P<int>[-+]?\d*)?(?:\.(?P<dec>\d*))?(?:[Ee](?P<exp>[-+]?\d+))?$`)
+
+// ParseDecimal128 takes the given string and attempts to parse it into a valid
+// Decimal128 value.
+func ParseDecimal128(s string) (Decimal128, error) {
+	if s == "" {
+		return dErr(s)
+	}
+
+	matches := normalNumber.FindStringSubmatch(s)
+	if len(matches) == 0 {
+		orig := s
+		neg := s[0] == '-'
+		if neg || s[0] == '+' {
+			s = s[1:]
+		}
+
+		if s == "NaN" || s == "nan" || strings.EqualFold(s, "nan") {
+			return dNaN, nil
+		}
+		if s == "Inf" || s == "inf" || strings.EqualFold(s, "inf") || strings.EqualFold(s, "infinity") {
+			if neg {
+				return dNegInf, nil
+			}
+			return dPosInf, nil
+		}
+		return dErr(orig)
+	}
+
+	intPart := matches[1]
+	decPart := matches[2]
+	expPart := matches[3]
+
+	var err error
+	exp := 0
+	if expPart != "" {
+		exp, err = strconv.Atoi(expPart)
+		if err != nil {
+			return dErr(s)
+		}
+	}
+	if decPart != "" {
+		exp -= len(decPart)
+	}
+
+	if len(strings.Trim(intPart+decPart, "-0")) > 35 {
+		return dErr(s)
+	}
+
+	bi, ok := new(big.Int).SetString(intPart+decPart, 10)
+	if !ok {
+		return dErr(s)
+	}
+
+	d, ok := ParseDecimal128FromBigInt(bi, exp)
+	if !ok {
+		return dErr(s)
+	}
+
+	if bi.Sign() == 0 && s[0] == '-' {
+		d.h |= 1 << 63
+	}
+
+	return d, nil
+}
+
+var (
+	ten  = big.NewInt(10)
+	zero = new(big.Int)
+
+	maxS, _ = new(big.Int).SetString("9999999999999999999999999999999999", 10)
+)
+
+// ParseDecimal128FromBigInt attempts to parse the given significand and exponent into a valid Decimal128 value.
+func ParseDecimal128FromBigInt(bi *big.Int, exp int) (Decimal128, bool) {
+	//copy
+	bi = new(big.Int).Set(bi)
+
+	q := new(big.Int)
+	r := new(big.Int)
+
+	for bigIntCmpAbs(bi, maxS) == 1 {
+		bi, _ = q.QuoRem(bi, ten, r)
+		if r.Cmp(zero) != 0 {
+			return Decimal128{}, false
+		}
+		exp++
+		if exp > MaxDecimal128Exp {
+			return Decimal128{}, false
+		}
+	}
+
+	for exp < MinDecimal128Exp {
+		// Subnormal.
+		bi, _ = q.QuoRem(bi, ten, r)
+		if r.Cmp(zero) != 0 {
+			return Decimal128{}, false
+		}
+		exp++
+	}
+	for exp > MaxDecimal128Exp {
+		// Clamped.
+		bi.Mul(bi, ten)
+		if bigIntCmpAbs(bi, maxS) == 1 {
+			return Decimal128{}, false
+		}
+		exp--
+	}
+
+	b := bi.Bytes()
+	var h, l uint64
+	for i := 0; i < len(b); i++ {
+		if i < len(b)-8 {
+			h = h<<8 | uint64(b[i])
+			continue
+		}
+		l = l<<8 | uint64(b[i])
+	}
+
+	h |= uint64(exp-MinDecimal128Exp) & uint64(1<<14-1) << 49
+	if bi.Sign() == -1 {
+		h |= 1 << 63
+	}
+
+	return Decimal128{h: h, l: l}, true
+}
+
+// bigIntCmpAbs computes big.Int.Cmp(absoluteValue(x), absoluteValue(y)).
+func bigIntCmpAbs(x, y *big.Int) int {
+	xAbs := bigIntAbsValue(x)
+	yAbs := bigIntAbsValue(y)
+	return xAbs.Cmp(yAbs)
+}
+
+// bigIntAbsValue returns a big.Int containing the absolute value of b.
+// If b is already a non-negative number, it is returned without any changes or copies.
+func bigIntAbsValue(b *big.Int) *big.Int {
+	if b.Sign() >= 0 {
+		return b // already positive
+	}
+	return new(big.Int).Abs(b)
+}