Addition expression implementation

go/sqltypes/arithmetic.go

@@ -19,6 +19,8 @@ package sqltypes
 import (
 	"bytes"
 	"fmt"
+	"math"
+
 	"strconv"
 
 	querypb "vitess.io/vitess/go/vt/proto/query"
@@ -40,6 +42,27 @@ type numeric struct {
 
 var zeroBytes = []byte("0")
 
+//Addition adds two values together
+//if v1 or v2 is null, then it returns null
+func Addition(v1, v2 Value) (Value, error) {
+	if v1.IsNull() || v2.IsNull() {
+		return NULL, nil
+	}
+	lv1, err := newNumeric(v1)
+	if err != nil {
+		return NULL, err
+	}
+	lv2, err := newNumeric(v2)
+	if err != nil {
+		return NULL, err
+	}
+	lresult, err := addNumericWithError(lv1, lv2)
+	if err != nil {
+		return NULL, err
+	}
+	return castFromNumeric(lresult, lresult.typ), nil
+}
+
 // NullsafeAdd adds two Values in a null-safe manner. A null value
 // is treated as 0. If both values are null, then a null is returned.
 // If both values are not null, a numeric value is built
@@ -51,7 +74,7 @@ var zeroBytes = []byte("0")
 // addition, if one of the input types was Decimal, then
 // a Decimal is built. Otherwise, the final type of the
 // result is preserved.
-func NullsafeAdd(v1, v2 Value, resultType querypb.Type) (Value, error) {
+func NullsafeAdd(v1, v2 Value, resultType querypb.Type) Value {
 	if v1.IsNull() {
 		v1 = MakeTrusted(resultType, zeroBytes)
 	}
@@ -61,16 +84,14 @@ func NullsafeAdd(v1, v2 Value, resultType querypb.Type) (Value, error) {
 
 	lv1, err := newNumeric(v1)
 	if err != nil {
-		return NULL, err
+		return NULL
 	}
 	lv2, err := newNumeric(v2)
 	if err != nil {
-		return NULL, err
-	}
-	lresult, err := addNumeric(lv1, lv2)
-	if err != nil {
-		return NULL, err
+		return NULL
 	}
+	lresult := addNumeric(lv1, lv2)
+
 	return castFromNumeric(lresult, resultType)
 }
 
@@ -200,6 +221,7 @@ func ToUint64(v Value) (uint64, error) {
 	case Uint64:
 		return num.uval, nil
 	}
+
 	panic("unreachable")
 }
 
@@ -219,6 +241,7 @@ func ToInt64(v Value) (int64, error) {
 		}
 		return ival, nil
 	}
+
 	panic("unreachable")
 }
 
@@ -236,7 +259,9 @@ func ToFloat64(v Value) (float64, error) {
 	case Float64:
 		return num.fval, nil
 	}
+
 	panic("unreachable")
+
 }
 
 // ToNative converts Value to a native go type.
@@ -323,17 +348,35 @@ func newIntegralNumeric(v Value) (numeric, error) {
 	return numeric{}, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "could not parse value: '%s'", str)
 }
 
-func addNumeric(v1, v2 numeric) (numeric, error) {
+func addNumeric(v1, v2 numeric) numeric {
 	v1, v2 = prioritize(v1, v2)
 	switch v1.typ {
 	case Int64:
-		return intPlusInt(v1.ival, v2.ival), nil
+		return intPlusInt(v1.ival, v2.ival)
 	case Uint64:
 		switch v2.typ {
 		case Int64:
 			return uintPlusInt(v1.uval, v2.ival)
 		case Uint64:
-			return uintPlusUint(v1.uval, v2.uval), nil
+			return uintPlusUint(v1.uval, v2.uval)
+		}
+	case Float64:
+		return floatPlusAny(v1.fval, v2)
+	}
+	panic("unreachable")
+}
+
+func addNumericWithError(v1, v2 numeric) (numeric, error) {
+	v1, v2 = prioritize(v1, v2)
+	switch v1.typ {
+	case Int64:
+		return intPlusIntWithError(v1.ival, v2.ival)
+	case Uint64:
+		switch v2.typ {
+		case Int64:
+			return uintPlusIntWithError(v1.uval, v2.ival)
+		case Uint64:
+			return uintPlusUintWithError(v1.uval, v2.uval)
 		}
 	case Float64:
 		return floatPlusAny(v1.fval, v2), nil
@@ -371,21 +414,58 @@ overflow:
 	return numeric{typ: Float64, fval: float64(v1) + float64(v2)}
 }
 
-func uintPlusInt(v1 uint64, v2 int64) (numeric, error) {
-	if v2 < 0 {
-		return numeric{}, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "cannot add a negative number to an unsigned integer: %d, %d", v1, v2)
+func intPlusIntWithError(v1, v2 int64) (numeric, error) {
+	result := v1 + v2
+	if v1 > 0 && v2 > 0 && result < 0 {
+		goto overflow
+	}
+	if v1 < 0 && v2 < 0 && result > 0 {
+		goto overflow
+	}
+	return numeric{typ: Int64, ival: result}, nil
+
+overflow:
+	return numeric{}, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "BIGINT value is out of range in %v + %v", v1, v2)
+}
+
+func uintPlusInt(v1 uint64, v2 int64) numeric {
+	return uintPlusUint(v1, uint64(v2))
+}
+
+func uintPlusIntWithError(v1 uint64, v2 int64) (numeric, error) {
+	if v2 >= math.MaxInt64 && v1 > 0 {
+		return numeric{}, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "BIGINT value is out of range in %v + %v", v1, v2)
+	}
+
+	if v1 >= math.MaxUint64 && v2 > 0 {
+
+		return numeric{}, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "BIGINT UNSIGNED value is out of range in %v + %v", v1, v2)
 	}
-	return uintPlusUint(v1, uint64(v2)), nil
+
+	//convert to int -> uint is because for numeric operators (such as + or -)
+	//where one of the operands is an unsigned integer, the result is unsigned by default.
+	return uintPlusUintWithError(v1, uint64(v2))
 }
 
 func uintPlusUint(v1, v2 uint64) numeric {
 	result := v1 + v2
 	if result < v2 {
 		return numeric{typ: Float64, fval: float64(v1) + float64(v2)}
+
 	}
 	return numeric{typ: Uint64, uval: result}
 }
 
+func uintPlusUintWithError(v1, v2 uint64) (numeric, error) {
+	result := v1 + v2
+
+	if result < v2 {
+		return numeric{}, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "BIGINT UNSIGNED value is out of range in %v + %v", v1, v2)
+	}
+
+	return numeric{typ: Uint64, uval: result}, nil
+}
+
 func floatPlusAny(v1 float64, v2 numeric) numeric {
 	switch v2.typ {
 	case Int64:
@@ -396,37 +476,43 @@ func floatPlusAny(v1 float64, v2 numeric) numeric {
 	return numeric{typ: Float64, fval: v1 + v2.fval}
 }
 
-func castFromNumeric(v numeric, resultType querypb.Type) (Value, error) {
+func castFromNumeric(v numeric, resultType querypb.Type) Value {
 	switch {
 	case IsSigned(resultType):
 		switch v.typ {
 		case Int64:
-			return MakeTrusted(resultType, strconv.AppendInt(nil, v.ival, 10)), nil
-		case Uint64, Float64:
-			return NULL, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "unexpected type conversion: %v to %v", v.typ, resultType)
+			return MakeTrusted(resultType, strconv.AppendInt(nil, v.ival, 10))
+		case Uint64:
+			return MakeTrusted(resultType, strconv.AppendInt(nil, int64(v.uval), 10))
+		case Float64:
+			return MakeTrusted(resultType, strconv.AppendInt(nil, int64(v.fval), 10))
+
 		}
 	case IsUnsigned(resultType):
 		switch v.typ {
 		case Uint64:
-			return MakeTrusted(resultType, strconv.AppendUint(nil, v.uval, 10)), nil
-		case Int64, Float64:
-			return NULL, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "unexpected type conversion: %v to %v", v.typ, resultType)
+			return MakeTrusted(resultType, strconv.AppendUint(nil, v.uval, 10))
+		case Int64:
+			return MakeTrusted(resultType, strconv.AppendUint(nil, uint64(v.ival), 10))
+		case Float64:
+			return MakeTrusted(resultType, strconv.AppendUint(nil, uint64(v.fval), 10))
+
 		}
 	case IsFloat(resultType) || resultType == Decimal:
 		switch v.typ {
 		case Int64:
-			return MakeTrusted(resultType, strconv.AppendInt(nil, v.ival, 10)), nil
+			return MakeTrusted(resultType, strconv.AppendInt(nil, v.ival, 10))
 		case Uint64:
-			return MakeTrusted(resultType, strconv.AppendUint(nil, v.uval, 10)), nil
+			return MakeTrusted(resultType, strconv.AppendUint(nil, v.uval, 10))
 		case Float64:
 			format := byte('g')
 			if resultType == Decimal {
 				format = 'f'
 			}
-			return MakeTrusted(resultType, strconv.AppendFloat(nil, v.fval, format, -1, 64)), nil
+			return MakeTrusted(resultType, strconv.AppendFloat(nil, v.fval, format, -1, 64))
 		}
 	}
-	return NULL, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "unexpected type conversion to non-numeric: %v", resultType)
+	return NULL
 }
 
 func compareNumeric(v1, v2 numeric) int {