core: vm: sqlvm: add shared variables (#228)

3 files changed, 19 insertions, 11 deletions

diff --git a/core/vm/sqlvm/ast/types.go b/core/vm/sqlvm/ast/types.go
index 19bcf6314..1928d2338 100644
--- a/core/vm/sqlvm/ast/types.go
+++ b/core/vm/sqlvm/ast/types.go
@@ -7,6 +7,7 @@ import (
 	"github.com/shopspring/decimal"
 
 	"github.com/dexon-foundation/dexon/common"
+	dec "github.com/dexon-foundation/dexon/core/vm/sqlvm/common/decimal"
 	se "github.com/dexon-foundation/dexon/core/vm/sqlvm/errors"
 )
 
@@ -20,11 +21,6 @@ type decPair struct {
 }
 
 var (
-	decOne = decimal.New(1, 0)
-
-	decFalse = decimal.Zero
-	decTrue  = decimal.New(1, 0)
-
 	decPairMap = make(map[DataType]decPair)
 )
 
@@ -260,18 +256,18 @@ func GetMinMax(dt DataType) (min, max decimal.Decimal, err error) {
 	major, minor := DecomposeDataType(dt)
 	switch major {
 	case DataTypeMajorBool:
-		min, max = decFalse, decTrue
+		min, max = dec.False, dec.True
 	case DataTypeMajorAddress:
 		bigUMax := new(big.Int).Lsh(bigIntOne, common.AddressLength*8)
-		max = decimal.NewFromBigInt(bigUMax, 0).Sub(decOne)
+		max = decimal.NewFromBigInt(bigUMax, 0).Sub(dec.One)
 	case DataTypeMajorInt:
 		bigMax := new(big.Int).Lsh(bigIntOne, (uint(minor)+1)*8-1)
 		decMax := decimal.NewFromBigInt(bigMax, 0)
-		min, max = decMax.Neg(), decMax.Sub(decOne)
+		min, max = decMax.Neg(), decMax.Sub(dec.One)
 	case DataTypeMajorUint,
 		DataTypeMajorFixedBytes:
 		bigUMax := new(big.Int).Lsh(bigIntOne, (uint(minor)+1)*8)
-		max = decimal.NewFromBigInt(bigUMax, 0).Sub(decOne)
+		max = decimal.NewFromBigInt(bigUMax, 0).Sub(dec.One)
 	default:
 		err = ErrGetMinMax
 		return
diff --git a/core/vm/sqlvm/ast/types_test.go b/core/vm/sqlvm/ast/types_test.go
index efdea17bc..17378d2bd 100644
--- a/core/vm/sqlvm/ast/types_test.go
+++ b/core/vm/sqlvm/ast/types_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/dexon-foundation/dexon/common"
+	dec "github.com/dexon-foundation/dexon/core/vm/sqlvm/common/decimal"
 	"github.com/shopspring/decimal"
 	"github.com/stretchr/testify/suite"
 )
@@ -154,14 +155,14 @@ func (s *TypesTestSuite) TestEncodeAndDecodeDecimal() {
 }
 
 func (s *TypesTestSuite) TestGetMinMax() {
-	decAddressMax := decimal.New(2, 0).Pow(decimal.New(common.AddressLength*8, 0)).Sub(decOne)
+	decAddressMax := decimal.New(2, 0).Pow(decimal.New(common.AddressLength*8, 0)).Sub(dec.One)
 	testcases := []struct {
 		Name     string
 		In       DataType
 		Min, Max decimal.Decimal
 		Err      error
 	}{
-		{"Bool", ComposeDataType(DataTypeMajorBool, 0), decFalse, decTrue, nil},
+		{"Bool", ComposeDataType(DataTypeMajorBool, 0), dec.False, dec.True, nil},
 		{"Address", ComposeDataType(DataTypeMajorAddress, 0), decimal.Zero, decAddressMax, nil},
 		{"Int8", ComposeDataType(DataTypeMajorInt, 0), decimal.New(-128, 0), decimal.New(127, 0), nil},
 		{"Int16", ComposeDataType(DataTypeMajorInt, 1), decimal.New(-32768, 0), decimal.New(32767, 0), nil},
diff --git a/core/vm/sqlvm/common/decimal/decimal.go b/core/vm/sqlvm/common/decimal/decimal.go
new file mode 100644
index 000000000..0c3d5971a
--- /dev/null
+++ b/core/vm/sqlvm/common/decimal/decimal.go
@@ -0,0 +1,11 @@
+package decimal
+
+import "github.com/shopspring/decimal"
+
+// Shared vars.
+var (
+	One = decimal.New(1, 0)
+
+	False = decimal.New(0, 0)
+	True  = decimal.New(1, 0)
+)