just return the 0 to make this hotpath faster

main.go

@@ -456,16 +456,8 @@ func ParseIp(ip string, ipv4Mask, ipv6Mask int) (string, string) {
 	// For IPv4 addresses
 	if parsedIP.To4() != nil {
 		mask := net.CIDRMask(ipv4Mask, 32)
-		network := parsedIP.Mask(mask)
-		subnet := []string{}
-		for _, octet := range strings.Split(network.String(), ".") {
-			if octet == "0" {
-				break
-			}
-			subnet = append(subnet, octet)
-		}
-
-		return ip, strings.Join(subnet, ".")
+		subnet := parsedIP.Mask(mask)
+		return ip, subnet.String()
 	}
 
 	// For IPv6 addresses

main_test.go

@@ -141,35 +141,35 @@ func TestParseIp(t *testing.T) {
 			ip:         "192.168.1.1",
 			ipv4Mask:   8,
 			wantFull:   "192.168.1.1",
-			wantSubnet: "192",
+			wantSubnet: "192.0.0.0",
 		},
 		{
 			name:       "IPv4 /10",
 			ip:         "192.168.1.1",
 			ipv4Mask:   10,
 			wantFull:   "192.168.1.1",
-			wantSubnet: "192.128",
+			wantSubnet: "192.128.0.0",
 		},
 		{
 			name:       "IPv4 /16",
 			ip:         "192.168.1.1",
 			ipv4Mask:   16,
 			wantFull:   "192.168.1.1",
-			wantSubnet: "192.168",
+			wantSubnet: "192.168.0.0",
 		},
 		{
 			name:       "IPv4 /20",
 			ip:         "192.168.1.1",
 			ipv4Mask:   20,
 			wantFull:   "192.168.1.1",
-			wantSubnet: "192.168",
+			wantSubnet: "192.168.0.0",
 		},
 		{
 			name:       "IPv4 /24",
 			ip:         "192.168.1.1",
 			ipv4Mask:   24,
 			wantFull:   "192.168.1.1",
-			wantSubnet: "192.168.1",
+			wantSubnet: "192.168.1.0",
 		},
 		{
 			name:       "IPv4 /32",