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Merge branch 'master' of https://github.com/piyongcai/decimal

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13981712066 2021-11-23 16:18:32 +08:00
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3 changed files with 48 additions and 17 deletions
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8
CHANGELOG.md
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@ -1,3 +1,11 @@
## Decimal v1.3.1
#### ENHANCEMENTS
- Reduce memory allocation in case of initialization from big.Int [#252](https://github.com/shopspring/decimal/pull/252)
#### BUGFIXES
- Fix binary marshalling of decimal zero value [#253](https://github.com/shopspring/decimal/pull/253)
## Decimal v1.3.0 ## Decimal v1.3.0
#### FEATURES #### FEATURES

18
decimal.go
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@ -120,7 +120,7 @@ func NewFromInt32(value int32) Decimal {
// NewFromBigInt returns a new Decimal from a big.Int, value * 10 ^ exp // NewFromBigInt returns a new Decimal from a big.Int, value * 10 ^ exp
func NewFromBigInt(value *big.Int, exp int32) Decimal { func NewFromBigInt(value *big.Int, exp int32) Decimal {
return Decimal{ return Decimal{
value: big.NewInt(0).Set(value), value: new(big.Int).Set(value),
exp: exp, exp: exp,
} }
} }
@ -552,7 +552,7 @@ func (d Decimal) Div(d2 Decimal) Decimal {
return d.DivRound(d2, int32(DivisionPrecision)) return d.DivRound(d2, int32(DivisionPrecision))
} }
// QuoRem does divsion with remainder // QuoRem does division with remainder
// d.QuoRem(d2,precision) returns quotient q and remainder r such that // d.QuoRem(d2,precision) returns quotient q and remainder r such that
// d = d2 * q + r, q an integer multiple of 10^(-precision) // d = d2 * q + r, q an integer multiple of 10^(-precision)
// 0 <= r < abs(d2) * 10 ^(-precision) if d>=0 // 0 <= r < abs(d2) * 10 ^(-precision) if d>=0
@ -628,7 +628,7 @@ func (d Decimal) DivRound(d2 Decimal, precision int32) Decimal {
// Mod returns d % d2. // Mod returns d % d2.
func (d Decimal) Mod(d2 Decimal) Decimal { func (d Decimal) Mod(d2 Decimal) Decimal {
quo := d.Div(d2).Truncate(0) quo := d.DivRound(d2, -d.exp+1).Truncate(0)
return d.Sub(d2.Mul(quo)) return d.Sub(d2.Mul(quo))
} }
@ -831,7 +831,7 @@ func (d Decimal) IsInteger() bool {
// When the exponent is negative we have to check every number after the decimal place // When the exponent is negative we have to check every number after the decimal place
// If all of them are zeroes, we are sure that given decimal can be represented as an integer // If all of them are zeroes, we are sure that given decimal can be represented as an integer
var r big.Int var r big.Int
q := big.NewInt(0).Set(d.value) q := new(big.Int).Set(d.value)
for z := abs(d.exp); z > 0; z-- { for z := abs(d.exp); z > 0; z-- {
q.QuoRem(q, tenInt, &r) q.QuoRem(q, tenInt, &r)
if r.Cmp(zeroInt) != 0 { if r.Cmp(zeroInt) != 0 {
@ -949,7 +949,7 @@ func (d Decimal) Exponent() int32 {
func (d Decimal) Coefficient() *big.Int { func (d Decimal) Coefficient() *big.Int {
d.ensureInitialized() d.ensureInitialized()
// we copy the coefficient so that mutating the result does not mutate the Decimal. // we copy the coefficient so that mutating the result does not mutate the Decimal.
return big.NewInt(0).Set(d.value) return new(big.Int).Set(d.value)
} }
// CoefficientInt64 returns the coefficient of the decimal as int64. It is scaled by 10^Exponent() // CoefficientInt64 returns the coefficient of the decimal as int64. It is scaled by 10^Exponent()
@ -1353,10 +1353,10 @@ func (d Decimal) MarshalJSON() ([]byte, error) {
// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface. As a string representation // UnmarshalBinary implements the encoding.BinaryUnmarshaler interface. As a string representation
// is already used when encoding to text, this method stores that string as []byte // is already used when encoding to text, this method stores that string as []byte
func (d *Decimal) UnmarshalBinary(data []byte) error { func (d *Decimal) UnmarshalBinary(data []byte) error {
// Verify we have at least 5 bytes, 4 for the exponent and at least 1 more // Verify we have at least 4 bytes for the exponent. The GOB encoded value
// for the GOB encoded value. // may be empty.
if len(data) < 5 { if len(data) < 4 {
return fmt.Errorf("error decoding binary %v: expected at least 5 bytes, got %d", data, len(data)) return fmt.Errorf("error decoding binary %v: expected at least 4 bytes, got %d", data, len(data))
} }
// Extract the exponent // Extract the exponent

27
decimal_test.go
View file

@ -2134,8 +2134,12 @@ func TestDecimal_Mod(t *testing.T) {
inputs := map[Inp]string{ inputs := map[Inp]string{
Inp{"3", "2"}: "1", Inp{"3", "2"}: "1",
Inp{"3451204593", "2454495034"}: "996709559", Inp{"3451204593", "2454495034"}: "996709559",
Inp{"24544.95034", ".3451204593"}: "0.3283950433", Inp{"9999999999", "1275"}: "324",
Inp{".1", ".1"}: "0", Inp{"9999999999.9999998", "1275.49"}: "239.2399998",
Inp{"24544.95034", "0.3451204593"}: "0.3283950433",
Inp{"0.499999999999999999", "0.25"}: "0.249999999999999999",
Inp{"0.989512958912895912", "0.000001"}: "0.000000958912895912",
Inp{"0.1", "0.1"}: "0",
Inp{"0", "1.001"}: "0", Inp{"0", "1.001"}: "0",
Inp{"-7.5", "2"}: "-1.5", Inp{"-7.5", "2"}: "-1.5",
Inp{"7.5", "-2"}: "1.5", Inp{"7.5", "-2"}: "1.5",
@ -3003,6 +3007,25 @@ func TestBinary(t *testing.T) {
} }
} }
func TestBinary_Zero(t *testing.T) {
var d1 Decimal
b, err := d1.MarshalBinary()
if err != nil {
t.Fatalf("error marshalling %v to binary: %v", d1, err)
}
var d2 Decimal
err = (&d2).UnmarshalBinary(b)
if err != nil {
t.Errorf("error unmarshalling from binary: %v", err)
}
if !d1.Equals(d2) {
t.Errorf("expected %v when restoring, got %v", d1, d2)
}
}
func TestBinary_DataTooShort(t *testing.T) { func TestBinary_DataTooShort(t *testing.T) {
var d Decimal var d Decimal