attributes, stun: refactor

attributes.go

@@ -7,26 +7,20 @@ import (
 	"strconv"
 )
 
-// blank is just blank string and exists just because it is ugly to keep it
-// in code.
-const blank = ""
-
 // Attributes is list of message attributes.
 type Attributes []Attribute
 
-// BlankAttribute is attribute that is returned by
-// Attributes.Get if nothing found.
-var BlankAttribute = Attribute{}
-
-// Get returns first attribute from list which match AttrType. If nothing
-// found, it returns blank attribute.
-func (a Attributes) Get(t AttrType) Attribute {
+// Get returns first attribute from list by the type.
+// If attribute is present the Attribute is returned and the
+// boolean is true. Otherwise the returned Attribute will be
+// empty and boolean will be false.
+func (a Attributes) Get(t AttrType) (Attribute, bool) {
 	for _, candidate := range a {
 		if candidate.Type == t {
-			return candidate
+			return candidate, true
 		}
 	}
-	return BlankAttribute
+	return Attribute{}, false
 }
 
 // AttrType is attribute type.
@@ -132,11 +126,6 @@ type Attribute struct {
 	Value  []byte
 }
 
-// IsBlank returns true if attribute equals to BlankAttribute.
-func (a Attribute) IsBlank() bool {
-	return a.Equal(BlankAttribute)
-}
-
 // Equal returns true if a == b.
 func (a Attribute) Equal(b Attribute) bool {
 	if a.Type != b.Type {
@@ -164,11 +153,11 @@ func (a Attribute) String() string {
 // if there is no value attribute with shuck type,
 // ErrAttributeNotFound is returned.
 func (m *Message) getAttrValue(t AttrType) ([]byte, error) {
-	v := m.Attributes.Get(t).Value
-	if len(v) == 0 {
+	v, ok := m.Attributes.Get(t)
+	if !ok {
 		return nil, ErrAttributeNotFound
 	}
-	return v, nil
+	return v.Value, nil
 }
 
 // AddSoftwareBytes adds SOFTWARE attribute with value from byte slice.
@@ -184,18 +173,16 @@ func (m *Message) AddSoftware(software string) {
 // GetSoftwareBytes returns SOFTWARE attribute value in byte slice.
 // If not found, returns nil.
 func (m *Message) GetSoftwareBytes() []byte {
-	return m.Attributes.Get(AttrSoftware).Value
+	v, ok := m.Attributes.Get(AttrSoftware)
+	if !ok {
+		return nil
+	}
+	return v.Value
 }
 
 // GetSoftware returns SOFTWARE attribute value in string.
 // If not found, returns blank string.
-func (m *Message) GetSoftware() string {
-	v := m.GetSoftwareBytes()
-	if len(v) == 0 {
-		return blank
-	}
-	return string(v)
-}
+func (m *Message) GetSoftware() string { return string(m.GetSoftwareBytes()) }
 
 // Address family values.
 const (

attributes_test.go

@@ -27,7 +27,10 @@ func TestMessage_AddSoftware(t *testing.T) {
 		t.Errorf("Expected %s, got %s.", v, vRead)
 	}
 
-	sAttr := m.Attributes.Get(AttrSoftware)
+	sAttr, ok := m.Attributes.Get(AttrSoftware)
+	if !ok {
+		t.Error("sowfware attribute should be found")
+	}
 	s := sAttr.String()
 	if !strings.HasPrefix(s, "SOFTWARE:") {
 		t.Error("bad string representation", s)
@@ -282,20 +285,3 @@ func TestMessage_AddErrorCodeDefault(t *testing.T) {
 		t.Error("bad reason", string(reason))
 	}
 }
-
-func TestAttribute_IsBlank(t *testing.T) {
-	var tt = [...]struct {
-		in  Attribute
-		out bool
-	}{
-		{BlankAttribute, true},                     // 0
-		{Attribute{Type: AttrUseCandidate}, false}, // 1
-		{Attribute{Value: []byte{1, 2, 3}}, false}, // 2
-		{Attribute{}, true},                        // 3
-	}
-	for i, v := range tt {
-		if got := v.in.IsBlank(); got != v.out {
-			t.Errorf("tt[%d]: (%+v).IsMessage %v != %v", i, v.in, got, v.out)
-		}
-	}
-}

stun-cli/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/codegangsta/cli"
@@ -15,6 +16,16 @@ const (
 	version = "0.2"
 )
 
+func normalize(address string) string {
+	if len(address) == 0 {
+		address = "0.0.0.0"
+	}
+	if !strings.Contains(address, ":") {
+		address = fmt.Sprintf("%s:%d", address, stun.DefaultPort)
+	}
+	return address
+}
+
 // Defaults for Client fields.
 const (
 	DefaultClientRetries  = 9
@@ -179,7 +190,7 @@ func discover(c *cli.Context) error {
 
 	request := Request{
 		Message: m,
-		Target:  stun.Normalize(c.String("server")),
+		Target:  normalize(c.String("server")),
 	}
 
 	return DefaultClient.Do(request, func(r Response) error {

stun.go

@@ -28,7 +28,6 @@ import (
 	"io"
 	"net"
 	"strconv"
-	"strings"
 	"sync"
 
 	"github.com/ernado/buffer"
@@ -39,17 +38,6 @@ var (
 	bin = binary.BigEndian
 )
 
-// Normalize returns normalized address.
-func Normalize(address string) string {
-	if len(address) == 0 {
-		address = "0.0.0.0"
-	}
-	if !strings.Contains(address, ":") {
-		address = fmt.Sprintf("%s:%d", address, DefaultPort)
-	}
-	return address
-}
-
 // DefaultPort is IANA assigned port for "stun" protocol.
 const DefaultPort = 3478
 
@@ -287,7 +275,10 @@ func (m Message) Equal(b Message) bool {
 		return false
 	}
 	for _, a := range m.Attributes {
-		aB := b.Attributes.Get(a.Type)
+		aB, ok := b.Attributes.Get(a.Type)
+		if !ok {
+			return false
+		}
 		if !aB.Equal(a) {
 			return false
 		}

stund/main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"strings"
 
 	"github.com/ernado/stun"
 	"github.com/pkg/errors"
@@ -156,11 +157,21 @@ func ListenUDPAndServe(serverNet, laddr string) error {
 	return s.Serve(c)
 }
 
+func normalize(address string) string {
+	if len(address) == 0 {
+		address = "0.0.0.0"
+	}
+	if !strings.Contains(address, ":") {
+		address = fmt.Sprintf("%s:%d", address, stun.DefaultPort)
+	}
+	return address
+}
+
 func main() {
 	flag.Parse()
 	switch *network {
 	case "udp":
-		normalized := stun.Normalize(*address)
+		normalized := normalize(*address)
 		fmt.Println("cydev/stun listening on", normalized, "via", *network)
 		log.Fatal(ListenUDPAndServe(*network, normalized))
 	default:

stund/server_test.go

@@ -1,9 +1,10 @@
 package main
 
 import (
-	"github.com/ernado/stun"
 	"net"
 	"testing"
+
+	"github.com/ernado/stun"
 )
 
 func BenchmarkBasicProcess(b *testing.B) {