Merge 86c2d2acf2 into 547861c49b

.github/workflows/ci.yml

@@ -1,15 +1,11 @@
 name: ci
-on:
+on: [push]
-  push:
-    branches:
-      - master
-  pull_request:
 jobs:
   ci-job:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: [ '1.10.x', '1.19', '1.20', '1.21', '1.22', '1.x' ]
+        go: [ '1.7.x', '1.18', '1.19', '1.20', '1.21', '1.x' ]
     name: Go ${{ matrix.go }}
     steps:
       - uses: actions/checkout@v4

CHANGELOG.md

@@ -1,30 +1,3 @@
-## Decimal v1.4.0
-#### BREAKING
-- Drop support for Go version older than 1.10 [#361](https://github.com/shopspring/decimal/pull/361)
-
-#### FEATURES
-- Add implementation of natural logarithm [#339](https://github.com/shopspring/decimal/pull/339) [#357](https://github.com/shopspring/decimal/pull/357)
-- Add improved implementation of power operation [#358](https://github.com/shopspring/decimal/pull/358)
-- Add Compare method which forwards calls to Cmp [#346](https://github.com/shopspring/decimal/pull/346)
-- Add NewFromBigRat constructor [#288](https://github.com/shopspring/decimal/pull/288)
-- Add NewFromUint64 constructor [#352](https://github.com/shopspring/decimal/pull/352)
-
-#### ENHANCEMENTS
-- Migrate to Github Actions [#245](https://github.com/shopspring/decimal/pull/245) [#340](https://github.com/shopspring/decimal/pull/340)
-- Fix examples for RoundDown, RoundFloor, RoundUp, and RoundCeil [#285](https://github.com/shopspring/decimal/pull/285) [#328](https://github.com/shopspring/decimal/pull/328) [#341](https://github.com/shopspring/decimal/pull/341)
-- Use Godoc standard to mark deprecated Equals and StringScaled methods [#342](https://github.com/shopspring/decimal/pull/342)
-- Removed unnecessary min function for RescalePair method [#265](https://github.com/shopspring/decimal/pull/265)
-- Avoid reallocation of initial slice in MarshalBinary (GobEncode) [#355](https://github.com/shopspring/decimal/pull/355)
-- Optimize NumDigits method [#301](https://github.com/shopspring/decimal/pull/301) [#356](https://github.com/shopspring/decimal/pull/356)
-- Optimize BigInt method [#359](https://github.com/shopspring/decimal/pull/359)
-- Support scanning uint64 [#131](https://github.com/shopspring/decimal/pull/131) [#364](https://github.com/shopspring/decimal/pull/364)
-- Add docs section with alternative libraries [#363](https://github.com/shopspring/decimal/pull/363)
-
-#### BUGFIXES
-- Fix incorrect calculation of decimal modulo [#258](https://github.com/shopspring/decimal/pull/258) [#317](https://github.com/shopspring/decimal/pull/317)
-- Allocate new(big.Int) in Copy method to deeply clone it [#278](https://github.com/shopspring/decimal/pull/278)
-- Fix overflow edge case in QuoRem method [#322](https://github.com/shopspring/decimal/pull/322)
-
 ## Decimal v1.3.1
 
 #### ENHANCEMENTS

README.md

@@ -22,12 +22,7 @@ Run `go get github.com/shopspring/decimal`
 
 ## Requirements 
 
-Decimal library requires Go version `>=1.10`
+Decimal library requires Go version `>=1.7`
-
-## Documentation
-
-http://godoc.org/github.com/shopspring/decimal
-
 
 ## Usage
 
@@ -64,16 +59,14 @@ func main() {
 }
 ```
 
-## Alternative libraries
+## Documentation
 
-When working with decimal numbers, you might face problems this library is not perfectly suited for. 
+http://godoc.org/github.com/shopspring/decimal
-Fortunately, thanks to the wonderful community we have a dozen other libraries that you can choose from.  
-Explore other alternatives to find the one that best fits your needs :)  
 
-* [cockroachdb/apd](https://github.com/cockroachdb/apd) - arbitrary precision, mutable and rich API similar to `big.Int`, more performant than this library 
+## Production Usage
-* [alpacahq/alpacadecimal](https://github.com/alpacahq/alpacadecimal) - high performance, low precision (12 digits), fully compatible API with this library 
+
-* [govalues/decimal](https://github.com/govalues/decimal) - high performance, zero-allocation, low precision (19 digits)
+* [Spring](https://shopspring.com/), since August 14, 2014.
-* [greatcloak/decimal](https://github.com/greatcloak/decimal) - fork focusing on billing and e-commerce web application related use cases, includes out-of-the-box BSON marshaling support
+* If you are using this in production, please let us know!
 
 ## FAQ
 

decimal.go

@@ -130,18 +130,6 @@ func NewFromInt32(value int32) Decimal {
 	}
 }
 
-// NewFromUint64 converts an uint64 to Decimal.
-//
-// Example:
-//
-//	NewFromUint64(123).String() // output: "123"
-func NewFromUint64(value uint64) Decimal {
-	return Decimal{
-		value: new(big.Int).SetUint64(value),
-		exp:   0,
-	}
-}
-
 // NewFromBigInt returns a new Decimal from a big.Int, value * 10 ^ exp
 func NewFromBigInt(value *big.Int, exp int32) Decimal {
 	return Decimal{
@@ -1236,33 +1224,14 @@ func (d Decimal) Ln(precision int32) (Decimal, error) {
 }
 
 // NumDigits returns the number of digits of the decimal coefficient (d.Value)
+// Note: Current implementation is extremely slow for large decimals and/or decimals with large fractional part
 func (d Decimal) NumDigits() int {
-	if d.value == nil {
+	d.ensureInitialized()
-		return 1
+	// Note(mwoss): It can be optimized, unnecessary cast of big.Int to string
+	if d.IsNegative() {
+		return len(d.value.String()) - 1
 	}
-
+	return len(d.value.String())
-	if d.value.IsInt64() {
-		i64 := d.value.Int64()
-		// restrict fast path to integers with exact conversion to float64
-		if i64 <= (1<<53) && i64 >= -(1<<53) {
-			if i64 == 0 {
-				return 1
-			}
-			return int(math.Log10(math.Abs(float64(i64)))) + 1
-		}
-	}
-
-	estimatedNumDigits := int(float64(d.value.BitLen()) / math.Log2(10))
-
-	// estimatedNumDigits (lg10) may be off by 1, need to verify
-	digitsBigInt := big.NewInt(int64(estimatedNumDigits))
-	errorCorrectionUnit := digitsBigInt.Exp(tenInt, digitsBigInt, nil)
-
-	if d.value.CmpAbs(errorCorrectionUnit) >= 0 {
-		return estimatedNumDigits + 1
-	}
-
-	return estimatedNumDigits
 }
 
 // IsInteger returns true when decimal can be represented as an integer value, otherwise, it returns false.
@@ -1418,7 +1387,9 @@ func (d Decimal) IntPart() int64 {
 // BigInt returns integer component of the decimal as a BigInt.
 func (d Decimal) BigInt() *big.Int {
 	scaledD := d.rescale(0)
-	return scaledD.value
+	i := &big.Int{}
+	i.SetString(scaledD.String(), 10)
+	return i
 }
 
 // BigFloat returns decimal as BigFloat.
@@ -1847,11 +1818,6 @@ func (d *Decimal) Scan(value interface{}) error {
 		*d = New(v, 0)
 		return nil
 
-	case uint64:
-		// while clickhouse may send 0 in db as uint64
-		*d = NewFromUint64(v)
-		return nil
-
 	default:
 		// default is trying to interpret value stored as string
 		str, err := unquoteIfQuoted(v)

decimal_bench_test.go

@@ -121,34 +121,6 @@ func BenchmarkDecimal_RoundCash_Five(b *testing.B) {
 	}
 }
 
-func numDigits(b *testing.B, want int, val Decimal) {
-	b.Helper()
-	for i := 0; i < b.N; i++ {
-		if have := val.NumDigits(); have != want {
-			b.Fatalf("\nHave: %d\nWant: %d", have, want)
-		}
-	}
-}
-
-func BenchmarkDecimal_NumDigits10(b *testing.B) {
-	numDigits(b, 10, New(3478512345, -3))
-}
-
-func BenchmarkDecimal_NumDigits100(b *testing.B) {
-	s := make([]byte, 102)
-	for i := range s {
-		s[i] = byte('0' + i%10)
-	}
-	s[0] = '-'
-	s[100] = '.'
-	d, err := NewFromString(string(s))
-	if err != nil {
-		b.Log(d)
-		b.Error(err)
-	}
-	numDigits(b, 100, d)
-}
-
 func Benchmark_Cmp(b *testing.B) {
 	decimals := DecimalSlice([]Decimal{})
 	for i := 0; i < 1000000; i++ {
@@ -160,7 +132,7 @@ func Benchmark_Cmp(b *testing.B) {
 	}
 }
 
-func BenchmarkDecimal_Add_different_precision(b *testing.B) {
+func Benchmark_decimal_Decimal_Add_different_precision(b *testing.B) {
 	d1 := NewFromFloat(1000.123)
 	d2 := NewFromFloat(500).Mul(NewFromFloat(0.12))
 
@@ -171,7 +143,7 @@ func BenchmarkDecimal_Add_different_precision(b *testing.B) {
 	}
 }
 
-func BenchmarkDecimal_Sub_different_precision(b *testing.B) {
+func Benchmark_decimal_Decimal_Sub_different_precision(b *testing.B) {
 	d1 := NewFromFloat(1000.123)
 	d2 := NewFromFloat(500).Mul(NewFromFloat(0.12))
 
@@ -182,7 +154,7 @@ func BenchmarkDecimal_Sub_different_precision(b *testing.B) {
 	}
 }
 
-func BenchmarkDecimal_Add_same_precision(b *testing.B) {
+func Benchmark_decimal_Decimal_Add_same_precision(b *testing.B) {
 	d1 := NewFromFloat(1000.123)
 	d2 := NewFromFloat(500.123)
 
@@ -193,7 +165,7 @@ func BenchmarkDecimal_Add_same_precision(b *testing.B) {
 	}
 }
 
-func BenchmarkDecimal_Sub_same_precision(b *testing.B) {
+func Benchmark_decimal_Decimal_Sub_same_precision(b *testing.B) {
 	d1 := NewFromFloat(1000.123)
 	d2 := NewFromFloat(500.123)
 

decimal_test.go

@@ -481,7 +481,6 @@ func TestNewFromInt(t *testing.T) {
 		1:                   "1",
 		323412345:           "323412345",
 		9223372036854775807: "9223372036854775807",
-		-9223372036854775808: "-9223372036854775808",
 	}
 
 	// add negatives
@@ -507,7 +506,6 @@ func TestNewFromInt32(t *testing.T) {
 		1:          "1",
 		323412345:  "323412345",
 		2147483647: "2147483647",
-		-2147483648: "-2147483648",
 	}
 
 	// add negatives
@@ -527,25 +525,6 @@ func TestNewFromInt32(t *testing.T) {
 	}
 }
 
-func TestNewFromUint64(t *testing.T) {
-	tests := map[uint64]string{
-		0:                    "0",
-		1:                    "1",
-		323412345:            "323412345",
-		9223372036854775807:  "9223372036854775807",
-		18446744073709551615: "18446744073709551615",
-	}
-
-	for input, s := range tests {
-		d := NewFromUint64(input)
-		if d.String() != s {
-			t.Errorf("expected %s, got %s (%s, %d)",
-				s, d.String(),
-				d.value.String(), d.exp)
-		}
-	}
-}
-
 func TestNewFromBigIntWithExponent(t *testing.T) {
 	type Inp struct {
 		val *big.Int
@@ -2417,57 +2396,104 @@ func TestDecimal_Max(t *testing.T) {
 	}
 }
 
-func scanHelper(t *testing.T, dbval interface{}, expected Decimal) {
+func TestDecimal_Scan(t *testing.T) {
-	t.Helper()
+	// test the Scan method that implements the
+	// sql.Scanner interface
+	// check for the for different type of values
+	// that are possible to be received from the database
+	// drivers
 
+	// in normal operations the db driver (sqlite at least)
+	// will return an int64 if you specified a numeric format
 	a := Decimal{}
-	if err := a.Scan(dbval); err != nil {
+	dbvalue := 54.33
+	expected := NewFromFloat(dbvalue)
+
+	err := a.Scan(dbvalue)
+	if err != nil {
 		// Scan failed... no need to test result value
-		t.Errorf("a.Scan(%v) failed with message: %s", dbval, err)
+		t.Errorf("a.Scan(54.33) failed with message: %s", err)
-	} else if !a.Equal(expected) {
+
+	} else {
 		// Scan succeeded... test resulting values
+		if !a.Equal(expected) {
 			t.Errorf("%s does not equal to %s", a, expected)
 		}
 	}
 
-func TestDecimal_Scan(t *testing.T) {
-	// test the Scan method that implements the sql.Scanner interface
-	// check different types received from various database drivers
-
-	dbvalue := 54.33
-	expected := NewFromFloat(dbvalue)
-	scanHelper(t, dbvalue, expected)
-
 	// apparently MySQL 5.7.16 and returns these as float32 so we need
 	// to handle these as well
 	dbvalueFloat32 := float32(54.33)
 	expected = NewFromFloat(float64(dbvalueFloat32))
-	scanHelper(t, dbvalueFloat32, expected)
+
+	err = a.Scan(dbvalueFloat32)
+	if err != nil {
+		// Scan failed... no need to test result value
+		t.Errorf("a.Scan(54.33) failed with message: %s", err)
+
+	} else {
+		// Scan succeeded... test resulting values
+		if !a.Equal(expected) {
+			t.Errorf("%s does not equal to %s", a, expected)
+		}
+	}
 
 	// at least SQLite returns an int64 when 0 is stored in the db
 	// and you specified a numeric format on the schema
 	dbvalueInt := int64(0)
 	expected = New(dbvalueInt, 0)
-	scanHelper(t, dbvalueInt, expected)
 
-	// also test uint64
+	err = a.Scan(dbvalueInt)
-	dbvalueUint64 := uint64(2)
+	if err != nil {
-	expected = New(2, 0)
+		// Scan failed... no need to test result value
-	scanHelper(t, dbvalueUint64, expected)
+		t.Errorf("a.Scan(0) failed with message: %s", err)
+
+	} else {
+		// Scan succeeded... test resulting values
+		if !a.Equal(expected) {
+			t.Errorf("%s does not equal to %s", a, expected)
+		}
+	}
 
 	// in case you specified a varchar in your SQL schema,
-	// the database driver may return either []byte or string
+	// the database driver will return byte slice []byte
 	valueStr := "535.666"
 	dbvalueStr := []byte(valueStr)
-	expected, err := NewFromString(valueStr)
+	expected, err = NewFromString(valueStr)
 	if err != nil {
 		t.Fatal(err)
 	}
-	scanHelper(t, dbvalueStr, expected)
+
-	scanHelper(t, valueStr, expected)
+	err = a.Scan(dbvalueStr)
+	if err != nil {
+		// Scan failed... no need to test result value
+		t.Errorf("a.Scan('535.666') failed with message: %s", err)
+
+	} else {
+		// Scan succeeded... test resulting values
+		if !a.Equal(expected) {
+			t.Errorf("%s does not equal to %s", a, expected)
+		}
+	}
+
+	// lib/pq can also return strings
+	expected, err = NewFromString(valueStr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = a.Scan(valueStr)
+	if err != nil {
+		// Scan failed... no need to test result value
+		t.Errorf("a.Scan('535.666') failed with message: %s", err)
+	} else {
+		// Scan succeeded... test resulting values
+		if !a.Equal(expected) {
+			t.Errorf("%s does not equal to %s", a, expected)
+		}
+	}
 
 	type foo struct{}
-	a := Decimal{}
 	err = a.Scan(foo{})
 	if err == nil {
 		t.Errorf("a.Scan(Foo{}) should have thrown an error but did not")

go.mod

@@ -1,3 +1,3 @@
 module github.com/piyongcai/decimal
 
-go 1.10
+go 1.7