crocochrome: get rid of the context of session

crocochrome.go

@@ -18,7 +18,7 @@ import (
 type Supervisor struct {
 	opts        Options
 	logger      *slog.Logger
-	sessions    map[string]*Session
+	sessions    map[string]context.CancelFunc
 	sessionsMtx sync.Mutex
 }
 
@@ -55,7 +55,7 @@ func New(logger *slog.Logger, opts Options) *Supervisor {
 	return &Supervisor{
 		opts:     opts.withDefaults(),
 		logger:   logger,
-		sessions: map[string]*Session{},
+		sessions: map[string]context.CancelFunc{},
 	}
 }
 
@@ -83,12 +83,7 @@ func (s *Supervisor) Session() (SessionInfo, error) {
 	logger := s.logger.With("sessionID", id)
 
 	ctx, cancel := context.WithTimeout(context.Background(), s.opts.SessionTimeout)
-	sess := &Session{
-		ctx:       ctx,
-		cancelCtx: cancel,
-		logger:    logger,
-	}
-	s.sessions[id] = sess
+	s.sessions[id] = cancel
 
 	context.AfterFunc(ctx, func() {
 		// Ensure that we call supervisor.delete to remove the session from the map its context is cancelled by
@@ -99,9 +94,18 @@ func (s *Supervisor) Session() (SessionInfo, error) {
 
 	go func() {
 		logger.Debug("starting session")
-		err := sess.Run(s.opts.ChromiumPath, s.opts.ChromiumPort)
-		if err != nil {
-			logger.Error("session terminated with an error", "err", err)
+		cmd := exec.CommandContext(ctx,
+			s.opts.ChromiumPath,
+			"--headless",
+			"--remote-debugging-address=0.0.0.0",
+			"--remote-debugging-port="+s.opts.ChromiumPort,
+			"--no-sandbox", // TODO: Sandbox.
+		)
+		cmd.Env = []string{}
+
+		err := cmd.Run()
+		if err != nil && !errors.Is(ctx.Err(), context.Canceled) {
+			logger.Error("running chromium", "err", err)
 		}
 	}()
 
@@ -129,8 +133,8 @@ func (s *Supervisor) Delete(sessionID string) bool {
 // delete cancels a session's context and removes it from the map, without locking the mutex.
 // It must be used only inside functions that already grab the lock.
 func (s *Supervisor) delete(sessionID string) bool {
-	if session, found := s.sessions[sessionID]; found {
-		session.Cancel()
+	if cancelSession, found := s.sessions[sessionID]; found {
+		cancelSession()
 		delete(s.sessions, sessionID)
 		return true
 	}
@@ -146,41 +150,6 @@ func (s *Supervisor) killExisting() {
 	}
 }
 
-// Session is a running instance of Chromium. It uses a (light, non-chroot) sandbox to run it.
-type Session struct {
-	ctx       context.Context
-	cancelCtx context.CancelFunc
-	logger    *slog.Logger
-}
-
-// Cancel cancels the context associated with this session.
-func (s *Session) Cancel() {
-	s.cancelCtx()
-}
-
-// Run starts the chromium process, and blocks until it returns. Upon termination, it automatically calls Session.Cancel
-// to clean up any pending operations.
-// By cancelling this context, the Session is removed from the Supervisor's map.
-func (s *Session) Run(chromiumPath, chromiumPort string) error {
-	defer s.Cancel()
-
-	cmd := exec.CommandContext(s.ctx,
-		chromiumPath,
-		"--headless",
-		"--remote-debugging-address=0.0.0.0",
-		"--remote-debugging-port="+chromiumPort,
-		"--no-sandbox", // TODO: Sandbox.
-	)
-	cmd.Env = []string{}
-
-	err := cmd.Run()
-	if err != nil && !errors.Is(s.ctx.Err(), context.Canceled) {
-		return fmt.Errorf("running chromium: %w", err)
-	}
-
-	return nil
-}
-
 // randString returns 12 random hex characters.
 func randString() string {
 	const IDLen = 12