func arithmeticFuncFactory(op opcode.Op) BuiltinFunc {
return func(args []types.Datum, _ context.Context) (d types.Datum, err error) {
a, err := types.CoerceArithmetic(args[0])
if err != nil {
return d, errors.Trace(err)
}
b, err := types.CoerceArithmetic(args[1])
if err != nil {
return d, errors.Trace(err)
}
a, b = types.CoerceDatum(a, b)
if a.IsNull() || b.IsNull() {
return
}
switch op {
case opcode.Plus:
return types.ComputePlus(a, b)
case opcode.Minus:
return types.ComputeMinus(a, b)
case opcode.Mul:
return types.ComputeMul(a, b)
case opcode.Div:
return types.ComputeDiv(a, b)
case opcode.Mod:
return types.ComputeMod(a, b)
case opcode.IntDiv:
return types.ComputeIntDiv(a, b)
default:
return d, ErrInvalidOperation.Gen("invalid op %v in arithmetic operation", op)
}
}
}
func (e *Evaluator) handleArithmeticOp(o *ast.BinaryOperationExpr) bool {
a, err := types.CoerceArithmetic(e.sc, *o.L.GetDatum())
if err != nil {
e.err = errors.Trace(err)
return false
}
b, err := types.CoerceArithmetic(e.sc, *o.R.GetDatum())
if err != nil {
e.err = errors.Trace(err)
return false
}
a, b, err = types.CoerceDatum(e.sc, a, b)
if err != nil {
e.err = errors.Trace(err)
return false
}
if a.IsNull() || b.IsNull() {
o.SetNull()
return true
}
var result types.Datum
switch o.Op {
case opcode.Plus:
result, e.err = types.ComputePlus(a, b)
case opcode.Minus:
result, e.err = types.ComputeMinus(a, b)
case opcode.Mul:
result, e.err = types.ComputeMul(a, b)
case opcode.Div:
result, e.err = types.ComputeDiv(e.sc, a, b)
case opcode.Mod:
result, e.err = types.ComputeMod(e.sc, a, b)
case opcode.IntDiv:
result, e.err = types.ComputeIntDiv(e.sc, a, b)
default:
e.err = ErrInvalidOperation.Gen("invalid op %v in arithmetic operation", o.Op)
return false
}
o.SetDatum(result)
return e.err == nil
}
// ComputeArithmetic computes the arithmetic operation on two datums.
func ComputeArithmetic(sc *variable.StatementContext, op tipb.ExprType, left types.Datum, right types.Datum) (types.Datum, error) {
var result types.Datum
a, err := types.CoerceArithmetic(sc, left)
if err != nil {
return result, errors.Trace(err)
}
b, err := types.CoerceArithmetic(sc, right)
if err != nil {
return result, errors.Trace(err)
}
a, b, err = types.CoerceDatum(sc, a, b)
if err != nil {
return result, errors.Trace(err)
}
if a.IsNull() || b.IsNull() {
return result, nil
}
switch op {
case tipb.ExprType_Plus:
return types.ComputePlus(a, b)
case tipb.ExprType_Div:
return types.ComputeDiv(sc, a, b)
case tipb.ExprType_Minus:
return types.ComputeMinus(a, b)
case tipb.ExprType_Mul:
return types.ComputeMul(a, b)
case tipb.ExprType_IntDiv:
return types.ComputeIntDiv(sc, a, b)
case tipb.ExprType_Mod:
return types.ComputeMod(sc, a, b)
default:
return result, errors.Errorf("Unknown binop type: %v", op)
}
}