Restructure handler function and move methods to clientContext

app/app.go

@@ -3,21 +3,16 @@ package app
 import (
 	"crypto/rand"
 	"encoding/base64"
-	"encoding/json"
 	"log"
 	"math/big"
 	"net/http"
-	"os"
 	"os/exec"
 	"strconv"
 	"strings"
-	"syscall"
-	"unsafe"
 
 	"github.com/elazarl/go-bindata-assetfs"
 	"github.com/gorilla/websocket"
 	"github.com/kr/pty"
-	"github.com/yudai/utf8reader"
 )
 
 type App struct {
@@ -126,108 +121,14 @@ func (app *App) handler(w http.ResponseWriter, r *http.Request) {
 	log.Printf("Command is running for client %s with PID %d", r.RemoteAddr, cmd.Process.Pid)
 
 	context := &clientContext{
+		app:        app,
 		request:    r,
 		connection: conn,
 		command:    cmd,
 		pty:        ptyIo,
 	}
 
-	app.goHandleConnection(context)
-}
-
-func (app *App) goHandleConnection(context *clientContext) {
-	exit := make(chan bool, 2)
-
-	go func() {
-		defer func() { exit <- true }()
-
-		app.processSend(context)
-	}()
-
-	go func() {
-		defer func() { exit <- true }()
-
-		app.processReceive(context)
-	}()
-
-	go func() {
-		<-exit
-		context.command.Wait()
-		context.connection.Close()
-		log.Printf("Connection closed: %s", context.request.RemoteAddr)
-	}()
-}
-
-func (app *App) processSend(context *clientContext) {
-	buf := make([]byte, 1024)
-	utf8f := utf8reader.New(context.pty)
-
-	for {
-		size, err := utf8f.Read(buf)
-		if err != nil {
-			log.Printf("Command exited for: %s", context.request.RemoteAddr)
-			return
-		}
-
-		writer, err := context.connection.NextWriter(websocket.TextMessage)
-		if err != nil {
-			return
-		}
-
-		writer.Write(buf[:size])
-		writer.Close()
-	}
-}
-
-func (app *App) processReceive(context *clientContext) {
-	for {
-		_, data, err := context.connection.ReadMessage()
-		if err != nil {
-			return
-		}
-
-		switch data[0] {
-		case Input:
-			if !app.options.PermitWrite {
-				break
-			}
-
-			_, err := context.pty.Write(data[1:])
-			if err != nil {
-				return
-			}
-
-		case ResizeTerminal:
-			var args argResizeTerminal
-			err = json.Unmarshal(data[1:], &args)
-			if err != nil {
-				log.Print("Malformed remote command")
-				return
-			}
-
-			window := struct {
-				row uint16
-				col uint16
-				x   uint16
-				y   uint16
-			}{
-				uint16(args.Rows),
-				uint16(args.Columns),
-				0,
-				0,
-			}
-			syscall.Syscall(
-				syscall.SYS_IOCTL,
-				context.pty.Fd(),
-				syscall.TIOCSWINSZ,
-				uintptr(unsafe.Pointer(&window)),
-			)
-
-		default:
-			log.Print("Unknown message type")
-			return
-		}
-	}
+	context.goHandleClient()
 }
 
 func generateRandomString(length int) string {
@@ -240,20 +141,3 @@ func generateRandomString(length int) string {
 	}
 	return string(n)
 }
-
-const (
-	Input          = '0'
-	ResizeTerminal = '1'
-)
-
-type argResizeTerminal struct {
-	Columns float64
-	Rows    float64
-}
-
-type clientContext struct {
-	request    *http.Request
-	connection *websocket.Conn
-	command    *exec.Cmd
-	pty        *os.File
-}

app/client_context.go

+package app
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"syscall"
+	"unsafe"
+
+	"github.com/gorilla/websocket"
+	"github.com/yudai/utf8reader"
+)
+
+type clientContext struct {
+	app        *App
+	request    *http.Request
+	connection *websocket.Conn
+	command    *exec.Cmd
+	pty        *os.File
+}
+
+const (
+	Input          = '0'
+	ResizeTerminal = '1'
+)
+
+type argResizeTerminal struct {
+	Columns float64
+	Rows    float64
+}
+
+func (context *clientContext) goHandleClient() {
+	exit := make(chan bool, 2)
+
+	go func() {
+		defer func() { exit <- true }()
+
+		context.processSend()
+	}()
+
+	go func() {
+		defer func() { exit <- true }()
+
+		context.processReceive()
+	}()
+
+	go func() {
+		<-exit
+		context.command.Wait()
+		context.connection.Close()
+		log.Printf("Connection closed: %s", context.request.RemoteAddr)
+	}()
+}
+
+func (context *clientContext) processSend() {
+	buf := make([]byte, 1024)
+	utf8f := utf8reader.New(context.pty)
+
+	for {
+		size, err := utf8f.Read(buf)
+		if err != nil {
+			log.Printf("Command exited for: %s", context.request.RemoteAddr)
+			return
+		}
+
+		writer, err := context.connection.NextWriter(websocket.TextMessage)
+		if err != nil {
+			return
+		}
+
+		writer.Write(buf[:size])
+		writer.Close()
+	}
+}
+
+func (context *clientContext) processReceive() {
+	for {
+		_, data, err := context.connection.ReadMessage()
+		if err != nil {
+			return
+		}
+
+		switch data[0] {
+		case Input:
+			if !context.app.options.PermitWrite {
+				break
+			}
+
+			_, err := context.pty.Write(data[1:])
+			if err != nil {
+				return
+			}
+
+		case ResizeTerminal:
+			var args argResizeTerminal
+			err = json.Unmarshal(data[1:], &args)
+			if err != nil {
+				log.Print("Malformed remote command")
+				return
+			}
+
+			window := struct {
+				row uint16
+				col uint16
+				x   uint16
+				y   uint16
+			}{
+				uint16(args.Rows),
+				uint16(args.Columns),
+				0,
+				0,
+			}
+			syscall.Syscall(
+				syscall.SYS_IOCTL,
+				context.pty.Fd(),
+				syscall.TIOCSWINSZ,
+				uintptr(unsafe.Pointer(&window)),
+			)
+
+		default:
+			log.Print("Unknown message type")
+			return
+		}
+	}
+}