added tabs to terminal, split single .go to separate files

internals/session.go

@@ -0,0 +1,128 @@
+package internals
+
+import (
+	"crypto/rand"
+	"fmt"
+	"os/exec"
+	"runtime"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/creack/pty"
+	"github.com/gorilla/websocket"
+)
+
+var (
+	sessions   = map[string]*Session{}
+	sessionsMu sync.Mutex
+)
+
+func shellQuote(s string) string {
+	return "'" + strings.ReplaceAll(s, "'", `'\''`) + "'"
+}
+
+func validID(id string) bool {
+	if len(id) != 32 {
+		return false
+	}
+	for _, c := range id {
+		if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
+			return false
+		}
+	}
+	return true
+}
+
+func randHex(n int) string {
+	b := make([]byte, n)
+	rand.Read(b)
+	return fmt.Sprintf("%x", b)
+}
+
+func getOrCreate(id string) *Session {
+	sessionsMu.Lock()
+	defer sessionsMu.Unlock()
+
+	if s, ok := sessions[id]; ok {
+		select {
+		case <-s.done:
+			delete(sessions, id)
+		default:
+			return s
+		}
+	}
+
+	s := &Session{
+		id:       id,
+		clients:  make(map[*client]struct{}),
+		done:     make(chan struct{}),
+		lastSeen: time.Now(),
+	}
+
+	var cmd *exec.Cmd
+	if runtime.GOOS == "windows" {
+		cmd = exec.Command("cmd.exe")
+	} else {
+		cmd = exec.Command("/bin/bash", "-i")
+	}
+	cmd.Dir = initialCwd
+
+	ptty, err := pty.Start(cmd)
+	if err != nil {
+		return nil
+	}
+	s.ptty = ptty
+	s.cmd = cmd
+	sessions[id] = s
+	go s.readLoop()
+	return s
+}
+
+func sessionByID(id string) *Session {
+	sessionsMu.Lock()
+	defer sessionsMu.Unlock()
+	s, ok := sessions[id]
+	if !ok {
+		return nil
+	}
+	select {
+	case <-s.done:
+		return nil
+	default:
+		return s
+	}
+}
+
+func (s *Session) readLoop() {
+	chunk := make([]byte, 16*1024)
+	for {
+		n, err := s.ptty.Read(chunk)
+		if n > 0 {
+			data := make([]byte, n)
+			copy(data, chunk[:n])
+
+			s.mu.Lock()
+			s.buf = append(s.buf, data...)
+			if len(s.buf) > maxBufSize {
+				s.buf = s.buf[len(s.buf)-maxBufSize:]
+			}
+			snapshot := make([]*client, 0, len(s.clients))
+			for c := range s.clients {
+				snapshot = append(snapshot, c)
+			}
+			s.mu.Unlock()
+
+			for _, c := range snapshot {
+				c.write(websocket.BinaryMessage, data)
+			}
+		}
+		if err != nil {
+			break
+		}
+	}
+	close(s.done)
+	sessionsMu.Lock()
+	delete(sessions, s.id)
+	sessionsMu.Unlock()
+}