Better loop/socket management.

main.go

@@ -6,6 +6,7 @@ import (
 	"net"
 	"os"
 	"strings"
+	"time"
 )
 
 var (
@@ -13,10 +14,16 @@ var (
 	sessionSubscription I3Session
 	workspaces []I3Workspace
 	outputIndices map[string]int
+	subscriptions []string
 )
 
 func init() {
 	outputIndices = make(map[string]int)
+	subscriptions = []string{
+		"binding",
+		"shutdown",
+	}
+
 	workspaces = []I3Workspace{
 		{ Num: 0, Name: "Development" },
 		{ Num: 1, Name: "Terminal" },
@@ -34,23 +41,7 @@ func init() {
 func main() {
 	var err error
 
-	// session is used for interactively communicating with i3,
+	go SessionLoop()
-	// like getting workspace and output data.
-	if session, err = NewI3Session(); err != nil {
-		fmt.Printf("%s\n", err)
-		os.Exit(1)
-	}
-	defer session.Close()
-
-	// sessionSubscription is used for listening to subscribed events
-	// from i3.
-	if sessionSubscription, err = NewI3Session(); err != nil {
-		fmt.Printf("%s\n", err)
-		os.Exit(1)
-	}
-	sessionSubscription.Subscribe([]string{"binding", "output"})
-	defer sessionSubscription.Close()
-	go sessionSubscription.Loop()
 
 	// Socket server reading commands and acting upon them
 	var listener net.Listener
@@ -60,13 +51,6 @@ func main() {
 		os.Exit(1)
 	}
 
-	// Find outputs and assign an index to them
-	err = session.UpdateOutputIndices()
-	if err != nil {
-		fmt.Printf("Output error: %s\n", err)
-		os.Exit(1)
-	}
-
 	// Listen for external commands
 	var conn net.Conn
 	var n int
@@ -82,13 +66,61 @@ func main() {
 		}
 
 		cmd := strings.TrimSpace(string(buf[:n]))
-		if cmd == "fix workspaces" {
+		switch(cmd) {
+		case "fix workspaces":
 			err = session.FixWorkspaces()
 			if err != nil {
 				fmt.Printf("Fix workspaces: %s\n", err)
 			}
+
+		case "outputs":
+			res, err := session.Socket.Request(GET_OUTPUTS, "")
+			if err != nil {
+				fmt.Printf("test error: %s\n", err)
+			}
+			fmt.Printf("test: %s\n", res)
 		}
 
 		conn.Close()
 	}
 }
+
+func SessionLoop() {
+	var err error
+	for {
+		fmt.Printf("-------- SessionLoop --------\n")
+
+		// session is used for interactively communicating with i3,
+		// like getting workspace and output data.
+		if err = session.Open(); err != nil {
+			fmt.Printf("%s\n", err)
+			continue
+		}
+
+		// sessionSubscription is used for listening to subscribed
+		// events from i3.
+		if err = sessionSubscription.Open(); err != nil {
+			fmt.Printf("%s\n", err)
+			continue
+		}
+
+		// i3-session-manager reacts to keybindings and i3 restarts.
+		sessionSubscription.Subscribe(subscriptions)
+
+		// Find outputs and assign an index to them
+		err = session.UpdateOutputIndices()
+		if err != nil {
+			fmt.Printf("Output error: %s\n", err)
+			os.Exit(1)
+		}
+
+
+		/* Loop will return on socket errors, for example when an i3
+		 * restart occurs. The socket will not be immediately available
+		 * then. Some connection errors can thus occur until i3 has
+		 * initialized the socket again. */
+		err = sessionSubscription.Loop()
+		fmt.Printf("Loop error: %s\n", err)
+		time.Sleep(time.Millisecond*100)
+	}
+}

session.go

@@ -4,20 +4,18 @@ import (
 	// Standard
 	"encoding/json"
 	"fmt"
-	"os"
 	"os/exec"
 	"regexp"
 	"strconv"
 	"strings"
 )
 
-// NewI3Session finds the i3 socket path and connects to it.
+func (sess *I3Session) Open() (err error) {
-func NewI3Session() (session I3Session, err error) {
 	// Find path to i3 socket
 	i3SocketPathCmd := exec.Command("i3", "--get-socketpath")
 	i3SocketPathBytes, _ := i3SocketPathCmd.CombinedOutput()
 	i3SocketPath := strings.TrimSpace(string(i3SocketPathBytes))
-	session.Socket, err = NewI3Socket(i3SocketPath)
+	sess.Socket, err = NewI3Socket(i3SocketPath)
 	return
 }
 
@@ -112,98 +110,6 @@ func (sess I3Session) Config() (config string, err error) {
 	return
 }
 
-func (sess I3Session) Loop() {
-	var msg []byte
-	var err error
-	var cmdBinding I3EventBinding
-
-	cmdOutput := regexp.MustCompile(`(?i)^\s*nop\s*output\s*(.*?)\s*$`)
-	cmdWS := regexp.MustCompile(`(?i)^\s*nop\s*workspace\s*(\d+)\s*$`)
-	cmdSession := regexp.MustCompile(`(?i)^\s*nop\s*manage\s+session`)
-	cmdMarkTag := regexp.MustCompile(`(?i)^\s*nop\s*mark\s+tag`)
-	cmdMarkMove := regexp.MustCompile(`(?i)^\s*nop\s*mark\s+move`)
-	cmdMarkClear := regexp.MustCompile(`(?i)^\s*nop\s*mark\s+clear`)
-
-	for {
-		msg, err = I3ReadMessage(sess.Socket)
-		if err != nil {
-			fmt.Printf("Loop error: %s\n", err)
-			os.Exit(1)
-		}
-
-		cmdBinding = I3EventBinding{}
-		err = json.Unmarshal(msg, &cmdBinding)
-		if err != nil {
-			fmt.Printf(
-				"Loop JSON parse: %s\n\nMessage:\n(%s)\n",
-				err,
-				msg,
-			)
-		}
-		binding := cmdBinding.Binding
-
-		// Switch output
-		m := cmdOutput.FindAllStringSubmatch(binding.Command, 1)
-		if len(m) == 1 && len(m[0]) == 2 {
-			err = sess.SwitchOutput(m[0][1])
-			if err != nil {
-				fmt.Printf("%s\n", err)
-			}
-			continue
-		}
-
-		// Switch output
-		m = cmdWS.FindAllStringSubmatch(binding.Command, 1)
-		if len(m) == 1 && len(m[0]) == 2 {
-			i, _ := strconv.Atoi(m[0][1])
-			err = sess.SwitchWorkspace(i)
-			if err != nil {
-				fmt.Printf("%s\n", err)
-			}
-			continue
-		}
-
-		// Manage session
-		if cmdSession.Match([]byte(binding.Command)) {
-			err = sess.ManageSession()
-			if err != nil {
-				fmt.Printf("Manage session: %s\n", err)
-			}
-			continue
-		}
-
-		// Mark current window with move tag
-		if cmdMarkTag.Match([]byte(binding.Command)) {
-			err = sess.MarkTag()
-			if err != nil {
-				fmt.Printf("Mark tag: %s\n", err)
-			}
-			continue
-		}
-
-		// Remove all move tags
-		if cmdMarkClear.Match([]byte(binding.Command)) {
-			err = sess.MarkClear()
-			if err != nil {
-				fmt.Printf("Mark clear: %s\n", err)
-			}
-			continue
-		}
-
-		// Move all windows with move tag
-		if cmdMarkMove.Match([]byte(binding.Command)) {
-			err = sess.MarkMove()
-			if err != nil {
-				fmt.Printf("Mark move: %s\n", err)
-			}
-			continue
-		}
-
-		fmt.Printf("%s\n", msg)
-
-	}
-}
-
 // SwitchWorkspace switches to the given workspace index on the same output
 // that has the workspace that is currently focused.
 func (sess I3Session) SwitchWorkspace(workspaceIndex int) error {
@@ -270,7 +176,7 @@ func (sess I3Session) SwitchOutput(output string) error {
 }
 
 // ManageSession runs dmenu and asks for reload, restart or exit.
-func (sess I3Session) ManageSession() error {
+func (sess *I3Session) ManageSession() error {
 	cmd := exec.Command(
 		"sh", "-c",
 		"echo \"reload\nrestart\nexit\" | dmenu -l 3 -i",
@@ -283,11 +189,14 @@ func (sess I3Session) ManageSession() error {
 
 	switch(choice) {
 	case "reload", "restart", "exit":
-		res, err := sess.Socket.Request(RUN_COMMAND, choice)
+		_, err = sess.Socket.Request(RUN_COMMAND, choice)
 		if err != nil {
 			return err
 		}
-		fmt.Printf("Management %s: %s\n", choice, res)
+
+		if choice == "restart" {
+			return fmt.Errorf("restarted")
+		}
 	default:
 		return fmt.Errorf("Unknown management command")
 	}
@@ -439,4 +348,100 @@ func (sess I3Session) FixWorkspaces() error {
 	return nil
 }
 
-// vim: foldmethod=marker
+// Loop reads the subscription socket and reacts to the implemented messages.
+func (sess *I3Session) Loop() error {
+	var msg []byte
+	var err error
+	var cmdBinding I3EventBinding
+
+	cmdOutput := regexp.MustCompile(`(?i)^\s*nop\s*output\s*(.*?)\s*$`)
+	cmdWS := regexp.MustCompile(`(?i)^\s*nop\s*workspace\s*(\d+)\s*$`)
+	cmdSession := regexp.MustCompile(`(?i)^\s*nop\s*manage\s+session`)
+	cmdMarkTag := regexp.MustCompile(`(?i)^\s*nop\s*mark\s+tag`)
+	cmdMarkMove := regexp.MustCompile(`(?i)^\s*nop\s*mark\s+move`)
+	cmdMarkClear := regexp.MustCompile(`(?i)^\s*nop\s*mark\s+clear`)
+
+	for {
+		msg, err = I3ReadMessage(sess.Socket)
+		if err != nil {
+			return err
+		}
+
+		cmdBinding = I3EventBinding{}
+		err = json.Unmarshal(msg, &cmdBinding)
+		if err != nil {
+			fmt.Printf(
+				"\nLoop JSON parse: %s\nMessage:\n(%s)\n\n",
+				err,
+				msg,
+			)
+		}
+		binding := cmdBinding.Binding
+
+		// Process is restarted
+		if cmdBinding.Change == "restart" {
+			return fmt.Errorf("restarted")
+		}
+
+		// Switch output
+		m := cmdOutput.FindAllStringSubmatch(binding.Command, 1)
+		if len(m) == 1 && len(m[0]) == 2 {
+			err = sess.SwitchOutput(m[0][1])
+			if err != nil {
+				fmt.Printf("%s\n", err)
+			}
+			continue
+		}
+
+		// Switch output
+		m = cmdWS.FindAllStringSubmatch(binding.Command, 1)
+		if len(m) == 1 && len(m[0]) == 2 {
+			i, _ := strconv.Atoi(m[0][1])
+			err = sess.SwitchWorkspace(i)
+			if err != nil {
+				fmt.Printf("%s\n", err)
+			}
+			continue
+		}
+
+		// Manage session
+		if cmdSession.Match([]byte(binding.Command)) {
+			err = sess.ManageSession()
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		// Mark current window with move tag
+		if cmdMarkTag.Match([]byte(binding.Command)) {
+			err = sess.MarkTag()
+			if err != nil {
+				fmt.Printf("Mark tag: %s\n", err)
+			}
+			continue
+		}
+
+		// Remove all move tags
+		if cmdMarkClear.Match([]byte(binding.Command)) {
+			err = sess.MarkClear()
+			if err != nil {
+				fmt.Printf("Mark clear: %s\n", err)
+			}
+			continue
+		}
+
+		// Move all windows with move tag
+		if cmdMarkMove.Match([]byte(binding.Command)) {
+			err = sess.MarkMove()
+			if err != nil {
+				fmt.Printf("Mark move: %s\n", err)
+			}
+			continue
+		}
+
+		//fmt.Printf("%s\n", msg)
+	}
+}
+
+// vim: foldmethod=syntax foldnestmax=1

socket.go

@@ -26,13 +26,18 @@ func NewI3Socket(filename string) (I3Socket, error) {
 	var i3Socket I3Socket
 	var err error
 
-	i3Socket.conn, err = net.Dial("unix", filename)
+	i3Socket.filename = filename
+	err = i3Socket.Open()
 	if err != nil {
 		return i3Socket, err
 	}
 
 	return i3Socket, nil
 }
+func (sock *I3Socket) Open() (err error) {
+	sock.conn, err = net.Dial("unix", sock.filename)
+	return
+}
 
 func (sock I3Socket) Close() error {
 	return sock.conn.Close()

types.go

@@ -7,6 +7,7 @@ import (
 
 type I3Session struct {
 	Socket I3Socket
+	filename string
 }
 
 type I3Socket struct {