improve performance by using less goroutines

- get rid of command channel in Client
- get rid of loginTimer; use other timers instead
- move debugging code to debug.go

irc/client.go

@@ -7,7 +7,6 @@ import (
 )
 
 const (
-	LOGIN_TIMEOUT = time.Minute / 2 // how long the client has to login
 	IDLE_TIMEOUT = time.Minute // how long before a client is considered idle
 	QUIT_TIMEOUT = time.Minute // how long after idle before a client is kicked
 )
@@ -19,14 +18,12 @@ type Client struct {
 	capabilities CapabilitySet
 	capState     CapState
 	channels     ChannelSet
-	commands     chan Command
 	ctime        time.Time
 	flags        map[UserMode]bool
 	hasQuit      bool
 	hops         uint
 	hostname     Name
 	idleTimer    *time.Timer
-	loginTimer   *time.Timer
 	nick         Name
 	quitTimer    *time.Timer
 	realname     Text
@@ -44,13 +41,12 @@ func NewClient(server *Server, conn net.Conn) *Client {
 		capState:     CapNone,
 		capabilities: make(CapabilitySet),
 		channels:     make(ChannelSet),
-		commands:     make(chan Command),
 		ctime:        now,
 		flags:        make(map[UserMode]bool),
 		server:       server,
+		socket:       NewSocket(conn),
 	}
-	client.socket = NewSocket(conn, client.commands)
-	client.loginTimer = time.AfterFunc(LOGIN_TIMEOUT, client.connectionTimeout)
+	client.Touch()
 	go client.run()
 
 	return client
@@ -61,8 +57,31 @@ func NewClient(server *Server, conn net.Conn) *Client {
 //
 
 func (client *Client) run() {
-	for command := range client.commands {
-		if checkPass, ok := command.(checkPasswordCommand); ok {
+	var command Command
+	var err error
+	var line string
+
+	// Set the hostname for this client. The client may later send a PROXY
+	// command from stunnel that sets the hostname to something more accurate.
+	client.send(NewProxyCommand(AddrLookupHostname(
+		client.socket.conn.RemoteAddr())))
+
+	for err == nil {
+		if line, err = client.socket.Read(); err != nil {
+			command = NewQuitCommand("connection closed")
+
+		} else if command, err = ParseCommand(line); err != nil {
+			switch err {
+			case ErrParseCommand:
+				client.Reply(RplNotice(client.server, client,
+					NewText("failed to parse command")))
+
+			case NotEnoughArgsError:
+				// TODO
+			}
+			continue
+
+		} else if checkPass, ok := command.(checkPasswordCommand); ok {
 			checkPass.LoadPassword(client.server)
 			// Block the client thread while handling a potentially expensive
 			// password bcrypt operation. Since the server is single-threaded
@@ -71,13 +90,20 @@ func (client *Client) run() {
 			// completes. This could be a form of DoS if handled naively.
 			checkPass.CheckPassword()
 		}
-		command.SetClient(client)
-		client.server.commands <- command
+
+		client.send(command)
 	}
 }
 
+func (client *Client) send(command Command) {
+	command.SetClient(client)
+	client.server.commands <- command
+}
+
+// quit timer goroutine
+
 func (client *Client) connectionTimeout() {
-	client.commands <- NewQuitCommand("connection timeout")
+	client.send(NewQuitCommand("connection timeout"))
 }
 
 //
@@ -109,7 +135,7 @@ func (client *Client) Touch() {
 }
 
 func (client *Client) Idle() {
-	client.Reply(RplPing(client))
+	client.Reply(RplPing(client.server))
 
 	if client.quitTimer == nil {
 		client.quitTimer = time.AfterFunc(QUIT_TIMEOUT, client.connectionTimeout)
@@ -123,7 +149,6 @@ func (client *Client) Register() {
 		return
 	}
 	client.registered = true
-	client.loginTimer.Stop()
 	client.Touch()
 }
 
@@ -140,9 +165,6 @@ func (client *Client) destroy() {
 
 	// clean up self
 
-	if client.loginTimer != nil {
-		client.loginTimer.Stop()
-	}
 	if client.idleTimer != nil {
 		client.idleTimer.Stop()
 	}

irc/commands.go

@@ -702,7 +702,6 @@ func ParseProxyCommand(args []string) (Command, error) {
 type AwayCommand struct {
 	BaseCommand
 	text Text
-	away bool
 }
 
 func ParseAwayCommand(args []string) (Command, error) {
@@ -710,7 +709,6 @@ func ParseAwayCommand(args []string) (Command, error) {
 
 	if len(args) > 0 {
 		cmd.text = NewText(args[0])
-		cmd.away = true
 	}
 
 	return cmd, nil

irc/debug.go

@@ -0,0 +1,68 @@
+package irc
+
+import (
+	"os"
+	"runtime"
+	"runtime/debug"
+	"runtime/pprof"
+	"time"
+)
+
+func (msg *DebugCommand) HandleServer(server *Server) {
+	client := msg.Client()
+	if !client.flags[Operator] {
+		return
+	}
+
+	switch msg.subCommand {
+	case "GCSTATS":
+		stats := debug.GCStats{
+			Pause:          make([]time.Duration, 10),
+			PauseQuantiles: make([]time.Duration, 5),
+		}
+		debug.ReadGCStats(&stats)
+
+		server.Replyf(client, "last GC:     %s", stats.LastGC.Format(time.RFC1123))
+		server.Replyf(client, "num GC:      %d", stats.NumGC)
+		server.Replyf(client, "pause total: %s", stats.PauseTotal)
+		server.Replyf(client, "pause quantiles min%%: %s", stats.PauseQuantiles[0])
+		server.Replyf(client, "pause quantiles 25%%:  %s", stats.PauseQuantiles[1])
+		server.Replyf(client, "pause quantiles 50%%:  %s", stats.PauseQuantiles[2])
+		server.Replyf(client, "pause quantiles 75%%:  %s", stats.PauseQuantiles[3])
+		server.Replyf(client, "pause quantiles max%%: %s", stats.PauseQuantiles[4])
+
+	case "NUMGOROUTINE":
+		count := runtime.NumGoroutine()
+		server.Replyf(client, "num goroutines: %d", count)
+
+	case "PROFILEHEAP":
+		profFile := "ergonomadic.mprof"
+		file, err := os.Create(profFile)
+		if err != nil {
+			server.Replyf(client, "error: %s", err)
+			break
+		}
+		defer file.Close()
+		pprof.Lookup("heap").WriteTo(file, 0)
+		server.Replyf(client, "written to %s", profFile)
+
+	case "STARTCPUPROFILE":
+		profFile := "ergonomadic.prof"
+		file, err := os.Create(profFile)
+		if err != nil {
+			server.Replyf(client, "error: %s", err)
+			break
+		}
+		if err := pprof.StartCPUProfile(file); err != nil {
+			defer file.Close()
+			server.Replyf(client, "error: %s", err)
+			break
+		}
+
+		server.Replyf(client, "CPU profile writing to %s", profFile)
+
+	case "STOPCPUPROFILE":
+		pprof.StopCPUProfile()
+		server.Reply(client, "CPU profiling stopped")
+	}
+}

irc/reply.go

@@ -151,8 +151,8 @@ func RplPing(target Identifiable) string {
 	return NewStringReply(nil, PING, ":%s", target.Nick())
 }
 
-func RplPong(client *Client) string {
-	return NewStringReply(nil, PONG, client.Nick().String())
+func RplPong(client *Client, msg Text) string {
+	return NewStringReply(nil, PONG, "%s :%s", client.server, msg.String())
 }
 
 func RplQuit(client *Client, message Text) string {

irc/server.go

@@ -8,9 +8,6 @@ import (
 	"net"
 	"os"
 	"os/signal"
-	"runtime"
-	"runtime/debug"
-	"runtime/pprof"
 	"strings"
 	"syscall"
 	"time"
@@ -121,7 +118,6 @@ func (server *Server) loadChannels() {
 
 func (server *Server) processCommand(cmd Command) {
 	client := cmd.Client()
-	Log.debug.Printf("%s → %+v", client, cmd)
 
 	if !client.registered {
 		regCmd, ok := cmd.(RegServerCommand)
@@ -138,6 +134,7 @@ func (server *Server) processCommand(cmd Command) {
 		client.ErrUnknownCommand(cmd.Code())
 		return
 	}
+
 	switch srvCmd.(type) {
 	case *PingCommand, *PongCommand:
 		client.Touch()
@@ -149,6 +146,7 @@ func (server *Server) processCommand(cmd Command) {
 		client.Active()
 		client.Touch()
 	}
+
 	srvCmd.HandleServer(server)
 }
 
@@ -272,6 +270,14 @@ func (s *Server) Nick() Name {
 	return s.Id()
 }
 
+func (server *Server) Reply(target *Client, message string) {
+	target.Reply(RplPrivMsg(server, target, NewText(message)))
+}
+
+func (server *Server) Replyf(target *Client, format string, args ...interface{}) {
+	server.Reply(target, fmt.Sprintf(format, args...))
+}
+
 //
 // registration commands
 //
@@ -344,7 +350,8 @@ func (m *PassCommand) HandleServer(s *Server) {
 }
 
 func (m *PingCommand) HandleServer(s *Server) {
-	m.Client().Reply(RplPong(m.Client()))
+	client := m.Client()
+	client.Reply(RplPong(client, m.server.Text()))
 }
 
 func (m *PongCommand) HandleServer(s *Server) {
@@ -514,23 +521,33 @@ func (msg *OperCommand) HandleServer(server *Server) {
 
 	client.flags[Operator] = true
 	client.RplYoureOper()
-	client.RplUModeIs(client)
+	client.Reply(RplModeChanges(client, client, ModeChanges{&ModeChange{
+		mode: Operator,
+		op:   Add,
+	}}))
 }
 
 func (msg *AwayCommand) HandleServer(server *Server) {
 	client := msg.Client()
-	if msg.away {
+	if len(msg.text) > 0 {
 		client.flags[Away] = true
 	} else {
 		delete(client.flags, Away)
 	}
 	client.awayMessage = msg.text
 
+	var op ModeOp
 	if client.flags[Away] {
+		op = Add
 		client.RplNowAway()
 	} else {
+		op = Remove
 		client.RplUnAway()
 	}
+	client.Reply(RplModeChanges(client, client, ModeChanges{&ModeChange{
+		mode: Away,
+		op:   op,
+	}}))
 }
 
 func (msg *IsOnCommand) HandleServer(server *Server) {
@@ -638,53 +655,6 @@ func (msg *NamesCommand) HandleServer(server *Server) {
 	}
 }
 
-func (server *Server) Reply(target *Client, format string, args ...interface{}) {
-	target.Reply(RplPrivMsg(server, target, NewText(fmt.Sprintf(format, args...))))
-}
-
-func (msg *DebugCommand) HandleServer(server *Server) {
-	client := msg.Client()
-	if !client.flags[Operator] {
-		return
-	}
-
-	switch msg.subCommand {
-	case "GC":
-		runtime.GC()
-		server.Reply(client, "OK")
-
-	case "GCSTATS":
-		stats := debug.GCStats{
-			Pause:          make([]time.Duration, 10),
-			PauseQuantiles: make([]time.Duration, 5),
-		}
-		debug.ReadGCStats(&stats)
-		server.Reply(client, "last GC:     %s", stats.LastGC.Format(time.RFC1123))
-		server.Reply(client, "num GC:      %d", stats.NumGC)
-		server.Reply(client, "pause total: %s", stats.PauseTotal)
-		server.Reply(client, "pause quantiles min%%: %s", stats.PauseQuantiles[0])
-		server.Reply(client, "pause quantiles 25%%:  %s", stats.PauseQuantiles[1])
-		server.Reply(client, "pause quantiles 50%%:  %s", stats.PauseQuantiles[2])
-		server.Reply(client, "pause quantiles 75%%:  %s", stats.PauseQuantiles[3])
-		server.Reply(client, "pause quantiles max%%: %s", stats.PauseQuantiles[4])
-
-	case "NUMGOROUTINE":
-		count := runtime.NumGoroutine()
-		server.Reply(client, "num goroutines: %d", count)
-
-	case "PROFILEHEAP":
-		profFile := "ergonomadic-heap.prof"
-		file, err := os.Create(profFile)
-		if err != nil {
-			log.Printf("error: %s", err)
-			break
-		}
-		defer file.Close()
-		pprof.Lookup("heap").WriteTo(file, 0)
-		server.Reply(client, "written to %s", profFile)
-	}
-}
-
 func (msg *VersionCommand) HandleServer(server *Server) {
 	client := msg.Client()
 	if (msg.target != "") && (msg.target != server.name) {

irc/socket.go

@@ -9,23 +9,20 @@ import (
 const (
 	R = '→'
 	W = '←'
-	EOF = ""
 )
 
 type Socket struct {
 	conn    net.Conn
+	scanner *bufio.Scanner
 	writer  *bufio.Writer
 }
 
-func NewSocket(conn net.Conn, commands chan<- Command) *Socket {
-	socket := &Socket{
+func NewSocket(conn net.Conn) *Socket {
+	return &Socket{
 		conn:    conn,
+		scanner: bufio.NewScanner(conn),
 		writer:  bufio.NewWriter(conn),
 	}
-
-	go socket.readLines(commands)
-
-	return socket
 }
 
 func (socket *Socket) String() string {
@@ -37,32 +34,22 @@ func (socket *Socket) Close() {
 	Log.debug.Printf("%s closed", socket)
 }
 
-func (socket *Socket) readLines(commands chan<- Command) {
-	commands <- NewProxyCommand(AddrLookupHostname(socket.conn.RemoteAddr()))
-
-	scanner := bufio.NewScanner(socket.conn)
-	for scanner.Scan() {
-		line := scanner.Text()
+func (socket *Socket) Read() (line string, err error) {
+	for socket.scanner.Scan() {
+		line = socket.scanner.Text()
 		if len(line) == 0 {
 			continue
 		}
 		Log.debug.Printf("%s → %s", socket, line)
-
-		msg, err := ParseCommand(line)
-		if err != nil {
-			// TODO error messaging to client
-			continue
-		}
-		commands <- msg
+		return
 	}
 
-	if err := scanner.Err(); err != nil {
-		Log.debug.Printf("%s error: %s", socket, err)
+	err = socket.scanner.Err()
+	socket.isError(err, R)
+	if err == nil {
+		err = io.EOF
 	}
-
-	commands <- NewQuitCommand("connection closed")
-
-	close(commands)
+	return
 }
 
 func (socket *Socket) Write(line string) (err error) {