Interface clean up.

command.go

@@ -31,12 +31,6 @@ type Command interface {
 	Apply(server *Server)
 }
 
-// This is a marker interface to filter out commands that are processed
-// internally by the protocol such as the "Join" command.
-type InternalCommand interface {
-	InternalCommand() bool
-}
-
 //------------------------------------------------------------------------------
 //
 // Functions
@@ -48,7 +42,7 @@ type InternalCommand interface {
 //--------------------------------------
 
 // Creates a new instance of a command by name.
-func NewCommand(name string) (Command, error) {
+func newCommand(name string) (Command, error) {
 	// Find the registered command.
 	command := commandTypes[name]
 	if command == nil {

join_command.go

@@ -22,11 +22,6 @@ type JoinCommand struct {
 //
 //------------------------------------------------------------------------------
 
-// This function marks the command as internal.
-func (c *JoinCommand) InternalCommand() bool {
-	return true
-}
-
 // The name of the command in the log.
 func (c *JoinCommand) CommandName() string {
 	return "raft:join"

log_entry.go

@@ -134,7 +134,7 @@ func (e *LogEntry) Decode(r io.Reader) (pos int, err error) {
 	}
 
 	// Instantiate command by name.
-	command, err := NewCommand(commandName)
+	command, err := newCommand(commandName)
 	if err != nil {
 		err = fmt.Errorf("raft.LogEntry: Unable to instantiate command (%s): %v", commandName, err)
 		return
@@ -184,7 +184,7 @@ func (e *LogEntry) UnmarshalJSON(data []byte) error {
 
 	// Create a command based on the name.
 	var err error
-	if e.Command, err = NewCommand(obj.Name); err != nil {
+	if e.Command, err = newCommand(obj.Name); err != nil {
 		return err
 	}
 	json.Unmarshal(obj.Command, e.Command)

server.go

@@ -36,7 +36,7 @@ var NotLeaderError = errors.New("Not current leader")
 // A server is involved in the consensus protocol and can act as a follower,
 // candidate or a leader.
 type Server struct {
-	JoinHandler          func(*Server, *Peer, Command) error
+	JoinHandler          func(*Server, *Peer, *JoinCommand) error
 	RequestVoteHandler   func(*Server, *Peer, *RequestVoteRequest) (*RequestVoteResponse, error)
 	AppendEntriesHandler func(*Server, *Peer, *AppendEntriesRequest) (*AppendEntriesResponse, error)
 	name                 string
@@ -353,7 +353,7 @@ loop:
 }
 
 // Executes the handler for doing a command on a particular peer.
-func (s *Server) executeJoinHandler(peer *Peer, command Command) error {
+func (s *Server) executeJoinHandler(peer *Peer, command *JoinCommand) error {
 	if s.JoinHandler == nil {
 		panic("raft.Server: JoinHandler not registered")
 	}

server_test.go

@@ -324,9 +324,9 @@ func TestServerMultiNode(t *testing.T) {
 	}
 	for _, name := range names {
 		server := newTestServer(name)
-		server.SetElectionTimeout(TestElectionTimeout)
-		server.SetHeartbeatTimeout(TestHeartbeatTimeout)
-		server.JoinHandler = func(server *Server, peer *Peer, command Command) error {
+		server.SetElectionTimeout(testElectionTimeout)
+		server.SetHeartbeatTimeout(testHeartbeatTimeout)
+		server.JoinHandler = func(server *Server, peer *Peer, command *JoinCommand) error {
 			mutex.Lock()
 			s := servers[peer.name]
 			mutex.Unlock()

test.go

@@ -8,8 +8,8 @@ import (
 )
 
 const (
-	TestHeartbeatTimeout = 20 * time.Millisecond
-	TestElectionTimeout  = 60 * time.Millisecond
+	testHeartbeatTimeout = 20 * time.Millisecond
+	testElectionTimeout  = 60 * time.Millisecond
 )
 
 func init() {
@@ -75,14 +75,14 @@ func newTestCluster(names []string) (Servers, map[string]*Server) {
 			panic(fmt.Sprintf("Duplicate server in test cluster! %v", name))
 		}
 		server := newTestServer(name)
-		server.SetElectionTimeout(TestElectionTimeout)
+		server.SetElectionTimeout(testElectionTimeout)
 		servers = append(servers, server)
 		lookup[name] = server
 	}
 	for _, server := range servers {
 		for _, peer := range servers {
 			if server != peer {
-				server.peers[peer.Name()] = NewPeer(server, peer.Name(), TestHeartbeatTimeout)
+				server.peers[peer.Name()] = NewPeer(server, peer.Name(), testHeartbeatTimeout)
 			}
 		}
 		server.Start()