Fix encoding so we split across txt records

encoding.go

@@ -6,119 +6,68 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"io/ioutil"
-
+	"strings"
-	"github.com/micro/go-micro/registry"
 )
 
-func encode(buf []byte) string {
+func encode(txt *mdnsTxt) ([]string, error) {
-	var b bytes.Buffer
+	b, err := json.Marshal(txt)
-	defer b.Reset()
+	if err != nil {
+		return nil, err
+	}
 
-	w := zlib.NewWriter(&b)
+	var buf bytes.Buffer
-	if _, err := w.Write(buf); err != nil {
+	defer buf.Reset()
-		return ""
+
+	w := zlib.NewWriter(&buf)
+	if _, err := w.Write(b); err != nil {
+		return nil, err
 	}
 	w.Close()
 
-	return hex.EncodeToString(b.Bytes())
+	encoded := hex.EncodeToString(buf.Bytes())
+
+	// individual txt limit
+	if len(encoded) <= 255 {
+		return []string{encoded}, nil
+	}
+
+	// split encoded string
+	var record []string
+
+	for len(encoded) > 255 {
+		record = append(record, encoded[:255])
+		encoded = encoded[255:]
+	}
+
+	record = append(record, encoded)
+
+	return record, nil
 }
 
-func decode(d string) []byte {
+func decode(record []string) (*mdnsTxt, error) {
-	hr, err := hex.DecodeString(d)
+	encoded := strings.Join(record, "")
+
+	hr, err := hex.DecodeString(encoded)
 	if err != nil {
-		return nil
+		return nil, err
 	}
 
 	br := bytes.NewReader(hr)
 	zr, err := zlib.NewReader(br)
 	if err != nil {
-		return nil
+		return nil, err
 	}
 
 	rbuf, err := ioutil.ReadAll(zr)
 	if err != nil {
-		return nil
+		return nil, err
 	}
 
-	return rbuf
+	var txt *mdnsTxt
-}
+
-
+	if err := json.Unmarshal(rbuf, &txt); err != nil {
-func encodeEndpoints(en []*registry.Endpoint) []string {
+		return nil, err
-	var tags []string
+	}
-	for _, e := range en {
+
-		if b, err := json.Marshal(e); err == nil {
+	return txt, nil
-			tags = append(tags, "e-"+encode(b))
-		}
-	}
-	return tags
-}
-
-func decodeEndpoints(tags []string) []*registry.Endpoint {
-	var en []*registry.Endpoint
-
-	for _, tag := range tags {
-		if len(tag) == 0 || tag[0] != 'e' || tag[1] != '-' {
-			continue
-		}
-
-		buf := decode(tag[2:])
-
-		var e *registry.Endpoint
-		if err := json.Unmarshal(buf, &e); err == nil {
-			en = append(en, e)
-		}
-	}
-	return en
-}
-
-func encodeMetadata(md map[string]string) []string {
-	var tags []string
-	for k, v := range md {
-		if b, err := json.Marshal(map[string]string{
-			k: v,
-		}); err == nil {
-			// new encoding
-			tags = append(tags, "t-"+encode(b))
-		}
-	}
-	return tags
-}
-
-func decodeMetadata(tags []string) map[string]string {
-	md := make(map[string]string)
-
-	for _, tag := range tags {
-		if len(tag) == 0 || tag[0] != 't' || tag[1] != '-' {
-			continue
-		}
-
-		buf := decode(tag[2:])
-
-		var kv map[string]string
-
-		// Now unmarshal
-		if err := json.Unmarshal(buf, &kv); err == nil {
-			for k, v := range kv {
-				md[k] = v
-			}
-		}
-	}
-	return md
-}
-
-func encodeVersion(v string) []string {
-	return []string{
-		// new encoding,
-		"v-" + encode([]byte(v)),
-	}
-}
-
-func decodeVersion(tags []string) (string, bool) {
-	for _, tag := range tags {
-		if len(tag) < 2 || tag[0] != 'v' || tag[1] != '-' {
-			continue
-		}
-		return string(decode(tag[2:])), true
-	}
-	return "", false
 }

encoding_test.go

@@ -1,14 +1,19 @@
 package mdns
 
 import (
-	"encoding/json"
 	"testing"
 
 	"github.com/micro/go-micro/registry"
 )
 
-func TestEncodingEndpoints(t *testing.T) {
+func TestEncoding(t *testing.T) {
-	eps := []*registry.Endpoint{
+	testData := []*mdnsTxt{
+		&mdnsTxt{
+			Version: "1.0.0",
+			Metadata: map[string]string{
+				"foo": "bar",
+			},
+			Endpoints: []*registry.Endpoint{
 				&registry.Endpoint{
 					Name: "endpoint1",
 					Request: &registry.Value{
@@ -23,125 +28,40 @@ func TestEncodingEndpoints(t *testing.T) {
 						"foo1": "bar1",
 					},
 				},
-		&registry.Endpoint{
-			Name: "endpoint2",
-			Request: &registry.Value{
-				Name: "request",
-				Type: "request",
-			},
-			Response: &registry.Value{
-				Name: "response",
-				Type: "response",
-			},
-			Metadata: map[string]string{
-				"foo2": "bar2",
-			},
-		},
-		&registry.Endpoint{
-			Name: "endpoint3",
-			Request: &registry.Value{
-				Name: "request",
-				Type: "request",
-			},
-			Response: &registry.Value{
-				Name: "response",
-				Type: "response",
-			},
-			Metadata: map[string]string{
-				"foo3": "bar3",
 			},
 		},
 	}
 
-	testEp := func(ep *registry.Endpoint, enc string) {
+	for _, d := range testData {
-		// encode endpoint
+		encoded, err := encode(d)
-		e := encodeEndpoints([]*registry.Endpoint{ep})
-
-		// check there are two tags; old and new
-		if len(e) != 1 {
-			t.Fatalf("Expected 1 encoded tag, got %v", e)
-		}
-
-		// check old encoding
-		var seen bool
-
-		for _, en := range e {
-			if en == enc {
-				seen = true
-				break
-			}
-		}
-
-		if !seen {
-			t.Fatalf("Expected %s but not found", enc)
-		}
-
-		// decode
-		d := decodeEndpoints([]string{enc})
-		if len(d) == 0 {
-			t.Fatalf("Expected %v got %v", ep, d)
-		}
-
-		// check name
-		if d[0].Name != ep.Name {
-			t.Fatalf("Expected ep %s got %s", ep.Name, d[0].Name)
-		}
-
-		// check all the metadata exists
-		for k, v := range ep.Metadata {
-			if gv := d[0].Metadata[k]; gv != v {
-				t.Fatalf("Expected key %s val %s got val %s", k, v, gv)
-			}
-		}
-	}
-
-	for _, ep := range eps {
-		// JSON encoded
-		jencoded, err := json.Marshal(ep)
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		// HEX encoded
+		for _, txt := range encoded {
-		hencoded := encode(jencoded)
+			if len(txt) > 255 {
-		// endpoint tag
+				t.Fatalf("One of parts for txt is %d characters", len(txt))
-		hepTag := "e-" + hencoded
-		testEp(ep, hepTag)
-	}
-}
-
-func TestEncodingVersion(t *testing.T) {
-	testData := []struct {
-		decoded string
-		encoded string
-	}{
-		{"1.0.0", "v-789c32d433d03300040000ffff02ce00ee"},
-		{"latest", "v-789cca492c492d2e01040000ffff08cc028e"},
-	}
-
-	for _, data := range testData {
-		e := encodeVersion(data.decoded)
-
-		if e[0] != data.encoded {
-			t.Fatalf("Expected %s got %s", data.encoded, e)
-		}
-
-		d, ok := decodeVersion(e)
-		if !ok {
-			t.Fatalf("Unexpected %t for %s", ok, data.encoded)
-		}
-
-		if d != data.decoded {
-			t.Fatalf("Expected %s got %s", data.decoded, d)
-		}
-
-		d, ok = decodeVersion([]string{data.encoded})
-		if !ok {
-			t.Fatalf("Unexpected %t for %s", ok, data.encoded)
-		}
-
-		if d != data.decoded {
-			t.Fatalf("Expected %s got %s", data.decoded, d)
-		}
 			}
+		}
+
+		decoded, err := decode(encoded)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if decoded.Version != d.Version {
+			t.Fatalf("Expected version %s got %s", d.Version, decoded.Version)
+		}
+
+		if len(decoded.Endpoints) != len(d.Endpoints) {
+			t.Fatalf("Expected %d endpoints, got %d", len(d.Endpoints), len(decoded.Endpoints))
+		}
+
+		for k, v := range d.Metadata {
+			if val := decoded.Metadata[k]; val != v {
+				t.Fatalf("Expected %s=%s got %s=%s", k, v, k, val)
+			}
+		}
+	}
+
 }

mdns.go

@@ -18,6 +18,12 @@ import (
 	hash "github.com/mitchellh/hashstructure"
 )
 
+type mdnsTxt struct {
+	Version   string
+	Endpoints []*registry.Endpoint
+	Metadata  map[string]string
+}
+
 type mdnsEntry struct {
 	hash uint64
 	id   string
@@ -103,10 +109,16 @@ func (m *mdnsRegistry) Register(service *registry.Service, opts ...registry.Regi
 			e = &mdnsEntry{hash: h}
 		}
 
-		var txt []string
+		txt, err := encode(&mdnsTxt{
-		txt = append(txt, encodeVersion(service.Version)...)
+			Version:   service.Version,
-		txt = append(txt, encodeMetadata(node.Metadata)...)
+			Endpoints: service.Endpoints,
-		//		txt = append(txt, encodeEndpoints(service.Endpoints)...)
+			Metadata:  node.Metadata,
+		})
+
+		if err != nil {
+			gerr = err
+			continue
+		}
 
 		// we got here, new node
 		s, err := mdns.NewMDNSService(
@@ -195,17 +207,17 @@ func (m *mdnsRegistry) GetService(service string) ([]*registry.Service, error) {
 					continue
 				}
 
-				version, exists := decodeVersion(e.InfoFields)
+				txt, err := decode(e.InfoFields)
-				if !exists {
+				if err != nil {
 					continue
 				}
 
-				s, ok := serviceMap[version]
+				s, ok := serviceMap[txt.Version]
 				if !ok {
 					s = &registry.Service{
 						Name:      service,
-						Version: version,
+						Version:   txt.Version,
-						//						Endpoints: decodeEndpoints(e.InfoFields),
+						Endpoints: txt.Endpoints,
 					}
 				}
 
@@ -213,10 +225,10 @@ func (m *mdnsRegistry) GetService(service string) ([]*registry.Service, error) {
 					Id:       strings.TrimSuffix(e.Name, "."+p.Service+"."+p.Domain+"."),
 					Address:  e.AddrV4.String(),
 					Port:     e.Port,
-					Metadata: decodeMetadata(e.InfoFields),
+					Metadata: txt.Metadata,
 				})
 
-				serviceMap[version] = s
+				serviceMap[txt.Version] = s
 			case <-exit:
 				return
 			}