go-kosu: update scaling methods to be consistent

packages/go-kosu/abci/rebalance.go

@@ -79,15 +79,15 @@ func posterIterator(app *App, totalBalance *big.Int) func(string, *types.Poster)
 // calculates a poster's period limit based on their balance and the total poster balance
 func posterLimit(periodLimit uint64, posterBalance, totalBalance *big.Int) uint64 {
 	// copy periodLimit (pl), posterBalance (pb), totalBalance (tb)
-	var pl, pb, tb big.Int
+	pl, pb, tb := &big.Int{}, &big.Int{}, &big.Int{}
 	pl.SetUint64(periodLimit)
 	pb.Set(posterBalance)
 	tb.Set(totalBalance)
 
 	// limit = (posterBalance / totalBalance) * periodLimit
 	limit := big.NewInt(0)
-	limit.Mul(&pl, &pb)
-	limit.Div(limit, &tb)
+	limit.Mul(pl, pb)
+	limit.Div(limit, tb)
 
 	if !limit.IsUint64() {
 		return math.MaxUint64

packages/go-kosu/abci/witness.go

@@ -102,15 +102,18 @@ func scaleBalance(balance *big.Int) int64 {
 		return int64(0)
 	}
 
-	scaled := &big.Rat{}
-	divisor := &big.Int{}
+	scaled := &big.Int{}
+	ether := &big.Int{}
+	scaled.Set(balance)
 
 	// scale balance by 10**18 (base units for KOSU)
+	// linter disabled for outdated gosec rule
 	// nolint:gosec
-	divisor = divisor.Exp(big.NewInt(10), big.NewInt(18), nil)
-	scaled.SetFrac(balance, divisor)
+	ether.Exp(big.NewInt(10), big.NewInt(18), big.NewInt(0))
+	scaled.Div(balance, ether)
 
-	res, _ := scaled.Float64()
-	power := math.Floor(res)
-	return int64(power)
+	if !scaled.IsInt64() {
+		return math.MaxInt64
+	}
+	return scaled.Int64()
 }