diff options
Diffstat (limited to 'core/vm/sqlvm/ast/types.go')
| -rw-r--r-- | core/vm/sqlvm/ast/types.go | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/core/vm/sqlvm/ast/types.go b/core/vm/sqlvm/ast/types.go index 48e7b1fb5..cb8c62c04 100644 --- a/core/vm/sqlvm/ast/types.go +++ b/core/vm/sqlvm/ast/types.go @@ -15,12 +15,26 @@ var ( bigIntTen = big.NewInt(10) ) +type decPair struct { + Min, Max decimal.Decimal +} + +var ( + decOne = decimal.New(1, 0) + + decFalse = decimal.Zero + decTrue = decimal.New(1, 0) + + decPairMap = make(map[DataType]decPair) +) + // Error defines. var ( ErrDataTypeEncode = errors.New("data type encode failed") ErrDataTypeDecode = errors.New("data type decode failed") ErrDecimalEncode = errors.New("decimal encode failed") ErrDecimalDecode = errors.New("decimal decode failed") + ErrGetMinMax = errors.New("get (min, max) failed") ) // DataTypeMajor defines type for high byte of DataType. @@ -272,3 +286,35 @@ func DecimalDecode(dt DataType, b []byte) (decimal.Decimal, error) { return decimal.Zero, ErrDecimalDecode } + +// GetMinMax returns min, max pair according to given data type. +func GetMinMax(dt DataType) (min, max decimal.Decimal, err error) { + cached, ok := decPairMap[dt] + if ok { + min, max = cached.Min, cached.Max + return + } + + major, minor := DecomposeDataType(dt) + switch major { + case DataTypeMajorBool: + min, max = decFalse, decTrue + case DataTypeMajorAddress: + bigUMax := new(big.Int).Lsh(bigIntOne, common.AddressLength*8) + max = decimal.NewFromBigInt(bigUMax, 0).Sub(decOne) + 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) + case DataTypeMajorUint, + DataTypeMajorFixedBytes: + bigUMax := new(big.Int).Lsh(bigIntOne, (uint(minor)+1)*8) + max = decimal.NewFromBigInt(bigUMax, 0).Sub(decOne) + default: + err = ErrGetMinMax + return + } + + decPairMap[dt] = decPair{Max: max, Min: min} + return +} |