Separated out the metadata about the agents and clients from the agentConnection and clientConnection objects. Now, the state does not need to be copied anymore when sending notifications.

The matchmaker uses copy on write every time a new agent or client connects or disconnects.

pkg/models/state.go

@@ -66,3 +66,15 @@ func NewState() *State {
 		Clients: collections.NewLinkedMap[ClientGuid, *Client](),
 	}
 }
+
+// for copy on write
+func (state *State) Copy() *State {
+	res := NewState()
+	for entry := range state.Agents.RangeEntries() {
+		res.Agents.Put(entry.Key, entry.Value)
+	}
+	for entry := range state.Clients.RangeEntries() {
+		res.Clients.Put(entry.Key, entry.Value)
+	}
+	return res
+}

pkg/server/admin/admin.go

@@ -16,7 +16,7 @@ import (
 )
 
 type agentConnection struct {
-	models.Agent
+	Info *models.Agent
 	// server session
 	CommChannel comms.CommChannel
 }
@@ -25,35 +25,37 @@ var agentIdGenerator = concurrency.NewAtomicCounter()
 var clientIdGenerator = concurrency.NewAtomicCounter()
 
 type ClientConnection struct {
-	models.Client
+	Info             *models.Client
 	agentConnection  net.Conn
 	clientConnection iowrappers2.ReadWriteAddrCloser
 }
 
 func newAgent(commChannel comms.CommChannel, publicId models.RendezVousId, agentInfo comms.EnvironmentInfo) *agentConnection {
-	return &agentConnection{
+	agent := models.Agent{
-		Agent: models.Agent{
 		Guid:            models.AgentGuid(strconv.Itoa(rand.Int())),
 		RemoteAddr:      models.RemoteAddr(commChannel.Session.RemoteAddr().String()),
 		PublicId:        publicId,
 		StartTime:       time.Now(),
 		EnvironmentInfo: agentInfo,
-		},
+	}
+	return &agentConnection{
+		Info:        &agent,
 		CommChannel: commChannel,
 	}
 }
 
 func newClient(publicId models.RendezVousId, clientConn iowrappers2.ReadWriteAddrCloser,
 	agentConn net.Conn, agentGuid models.AgentGuid) *ClientConnection {
-	return &ClientConnection{
+	client := models.Client{
-		Client: models.Client{
 		Guid:       models.ClientGuid(strconv.Itoa(rand.Int())),
 		RemoteAddr: models.RemoteAddr(clientConn.RemoteAddr().String()),
 		PublicId:   publicId,
 		AgentGuid:  agentGuid,
 		ClientId:   models.ClientId(strconv.Itoa(clientIdGenerator.IncrementAndGet())),
 		StartTime:  time.Now(),
-		},
+	}
+	return &ClientConnection{
+		Info:             &client,
 		agentConnection:  agentConn,
 		clientConnection: clientConn,
 	}
@@ -66,6 +68,12 @@ func (match *ClientConnection) Synchronize() {
 type Admin struct {
 	// map of public id to agent
 	mutex sync.Mutex
+	// for reporting state to webclients and prometheus and also used for
+	// logging the state. This uses copy-on-write. Every time an agent or
+	// clinet is added or removed a copy is made.
+	state *models.State
+
+	// TODO: use linked map for both of these
 	agents  map[models.RendezVousId]*agentConnection
 	clients []*ClientConnection
 }
@@ -73,6 +81,7 @@ type Admin struct {
 func NewAdmin() *Admin {
 	return &Admin{
 		mutex:   sync.Mutex{},
+		state:   models.NewState(),
 		agents:  make(map[models.RendezVousId]*agentConnection),
 		clients: make([]*ClientConnection, 0), // not strictly needed
 	}
@@ -81,30 +90,17 @@ func NewAdmin() *Admin {
 func (admin *Admin) CreateNotifification() *models.State {
 	admin.mutex.Lock()
 	defer admin.mutex.Unlock()
-	state := models.NewState()
+	return admin.state
-	for _, agent := range admin.agents {
-		state.Agents.Put(agent.Guid, &agent.Agent)
-	}
-	for _, client := range admin.clients {
-		state.Clients.Put(client.Guid, &client.Client)
-	}
-	return state
 }
 
 func (admin *Admin) getFreeId(publicId models.RendezVousId) (models.RendezVousId, error) {
-	usedIds := make(map[models.RendezVousId]bool)
+	if admin.agents[publicId] == nil {
-	for _, agent := range admin.agents {
-		usedIds[agent.PublicId] = true
-	}
-	if !usedIds[publicId] {
 		return publicId, nil
 	}
-	if usedIds[publicId] {
 	for i := 0; i < 100; i++ {
-			candidate := string(publicId) + "-" + strconv.Itoa(i)
+		candidate := models.RendezVousId(string(publicId) + "-" + strconv.Itoa(i))
-			if !usedIds[models.RendezVousId(candidate)] {
+		if admin.agents[candidate] == nil {
-				return models.RendezVousId(candidate), nil
+			return candidate, nil
-			}
 		}
 	}
 	return "", fmt.Errorf("Could not allocate agent id based on requested public id '%s'", publicId)
@@ -132,8 +128,8 @@ func (admin *Admin) AddAgent(publicId models.RendezVousId, agentInfo comms.Envir
 			Message: err.Error(),
 		})
 	}
-	agent := admin.agents[publicId]
+	agentCheck := admin.agents[publicId]
-	if agent != nil {
+	if agentCheck != nil {
 		return nil, fmt.Errorf("SHOULD NEVER GET HERE!!!, A different agent with same PublicId '%s' already registered", publicId)
 	}
 
@@ -142,7 +138,10 @@ func (admin *Admin) AddAgent(publicId models.RendezVousId, agentInfo comms.Envir
 	if err != nil {
 		return nil, err
 	}
-	agent = newAgent(commChannel, publicId, agentInfo)
+	agent := newAgent(commChannel, publicId, agentInfo)
+
+	admin.state = admin.state.Copy()
+	admin.state.Agents.Put(agent.Info.Guid, agent.Info)
 	admin.agents[publicId] = agent
 	return agent, nil
 }
@@ -165,17 +164,19 @@ func (admin *Admin) AddClient(publicId models.RendezVousId, clientConn iowrapper
 
 	log.Println("Sending connection information to agent")
 
-	client := newClient(publicId, clientConn, agentConn, agent.Guid)
+	client := newClient(publicId, clientConn, agentConn, agent.Info.Guid)
 
 	// Before using this connection for SSH we use it to send client metadata to the
 	// agent
 	err = comms.SendClientInfo(agentConn, comms.ClientInfo{
-		ClientId: string(client.ClientId),
+		ClientId: string(client.Info.ClientId),
 	})
 	if err != nil {
 		return nil, err
 	}
 
+	admin.state = admin.state.Copy()
+	admin.state.Clients.Put(client.Info.Guid, client.Info)
 	admin.clients = append(admin.clients, client)
 	return client, nil
 }
@@ -205,6 +206,8 @@ func (admin *Admin) RemoveAgent(publicId models.RendezVousId) error {
 	if err != nil {
 		log.Printf("Could not close yamux client session for '%s'\n", publicId)
 	}
+	admin.state = admin.state.Copy()
+	admin.state.Agents.Delete(agent.Info.Guid)
 	delete(admin.agents, publicId)
 	return nil
 }
@@ -213,14 +216,16 @@ func (admin *Admin) RemoveClient(client *ClientConnection) error {
 	admin.mutex.Lock()
 	defer admin.mutex.Unlock()
 
-	log.Printf("Removing client: '%s' created at %s\n", client.ClientId,
+	log.Printf("Removing client: '%s' created at %s\n", client.Info.Guid,
-		client.StartTime.Format(time.DateTime))
+		client.Info.StartTime.Format(time.DateTime))
 	// try to explicitly close connection to the agent.
 	_ = client.agentConnection.Close()
 	_ = client.clientConnection.Close()
 
 	for i, _client := range admin.clients {
-		if _client.ClientId == client.ClientId {
+		if _client.Info.ClientId == client.Info.ClientId {
+			admin.state = admin.state.Copy()
+			admin.state.Clients.Delete(client.Info.Guid)
 			admin.clients = append(admin.clients[:i], admin.clients[i+1:]...)
 			break
 		}
@@ -231,7 +236,7 @@ func (admin *Admin) RemoveClient(client *ClientConnection) error {
 func (admin *Admin) SetSessionType(clientId models.ClientId, sessionType models.SessionType) {
 	admin.mutex.Lock()
 	defer admin.mutex.Unlock()
-	for _, client := range admin.clients {
+	for client := range admin.state.Clients.RangeValues() {
 		if client.ClientId == clientId {
 			client.SessionType = sessionType
 			break

pkg/server/matchmaker/matchmaker.go

@@ -39,7 +39,7 @@ func (converge *MatchMaker) Register(publicId models.RendezVousId, conn io.ReadW
 	if err != nil {
 		return err
 	}
-	publicId = agent.PublicId
+	publicId = agent.Info.PublicId
 	defer func() {
 		converge.admin.RemoveAgent(publicId)
 		converge.logStatus()
@@ -48,7 +48,7 @@ func (converge *MatchMaker) Register(publicId models.RendezVousId, conn io.ReadW
 	go func() {
 		comms.ListenForAgentEvents(agent.CommChannel.SideChannel,
 			func(info comms.EnvironmentInfo) {
-				agent.EnvironmentInfo = info
+				agent.Info.EnvironmentInfo = info
 				converge.logStatus()
 			},
 			func(session comms.SessionInfo) {
@@ -56,7 +56,7 @@ func (converge *MatchMaker) Register(publicId models.RendezVousId, conn io.ReadW
 				converge.admin.SetSessionType(models.ClientId(session.ClientId), models.SessionType(session.SessionType))
 			},
 			func(expiry comms.ExpiryTimeUpdate) {
-				agent.SetExpiryTime(expiry.ExpiryTime)
+				agent.Info.SetExpiryTime(expiry.ExpiryTime)
 				converge.logStatus()
 			})
 	}()
@@ -114,7 +114,7 @@ func (converge *MatchMaker) Connect(wsProxyMode bool, publicId models.RendezVous
 		if err != nil {
 			return fmt.Errorf("Error receiving environment info from client: %v", err)
 		}
-		client.EnvironmentInfo = clientEnvironment
+		client.Info.EnvironmentInfo = clientEnvironment
 	}
 	converge.logStatus()
 	client.Synchronize()