Restructure handler function and move methods to clientContext

app/client_context.go

@@ -0,0 +1,127 @@
+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
+		}
+	}
+}