Adding sync around timeline, adding hooks for latency checks

app/cli/main.go

@@ -299,7 +299,8 @@ func main() {
 				if group == nil {
 					fmt.Printf("Error: group does not exist\n")
 				} else {
-					for _, m := range group.Timeline.Messages {
+					timeline := group.GetTimeline()
+					for _, m := range timeline.Messages {
 						verified := "not-verified"
 						if m.Verified {
 							verified = "verified"

model/group.go

@@ -9,6 +9,7 @@ import (
 	"golang.org/x/crypto/nacl/secretbox"
 	"io"
 	"time"
+	"sync"
 )
 
 //Group defines and encapsulates Cwtch's conception of group chat. Which are sessions
@@ -21,6 +22,7 @@ type Group struct {
 	Timeline      Timeline
 	Accepted      bool
 	Owner         string
+	lock 		  sync.Mutex
 }
 
 // NewGroup initializes a new group associated with a given CwtchServer
@@ -64,26 +66,27 @@ func (g *Group) Invite() []byte {
 }
 
 func (g *Group) AddMessage(message *protocol.DecryptedGroupMessage, verified bool) *Message {
+	g.lock.Lock()
 	timelineMessage := &Message{
 		Message:            message.GetText(),
 		Timestamp:          time.Unix(int64(message.GetTimestamp()), 0),
+		Received:			time.Now(),
 		Signature:          message.GetSignature(),
 		Verified:           verified,
 		PeerID:             message.GetOnion(),
 		PreviousMessageSig: message.GetPreviousMessageSig(),
 	}
 	g.Timeline.Insert(timelineMessage)
+	g.lock.Unlock()
 	return timelineMessage
 }
 
-// AddMember ...
+func (g *Group) GetTimeline() (t Timeline) {
-func (g *Group) AddMember() {
+	g.lock.Lock()
-	// TODO: Rotate Key
+	t = g.Timeline
-}
+	g.lock.Unlock()
+	return
 
-// RemoveMember ...
-func (g *Group) RemoveMember() {
-	// TODO: Rotate Key
 }
 
 //EncryptMessage takes a message and encrypts the message under the group key.

model/message.go

@@ -14,6 +14,7 @@ type Timeline struct {
 // Message is a local representation of a given message sent over a group chat channel.
 type Message struct {
 	Timestamp          time.Time
+	Received		   time.Time
 	PeerID             string
 	Message            string
 	Signature          []byte