commit 25d431a6c23ee49bd0d0fe11748caa3a5e8e72ed
parent b7a49256f55c187854ff8a3ab55b47d53bdb3d19
Author: Matsuda Kenji <info@mtkn.jp>
Date: Thu, 26 Oct 2023 07:35:21 +0900
add comment
Diffstat:
| M | server.go | | | 35 | +++++++++++++++++++++++++++++++---- |
1 file changed, 31 insertions(+), 4 deletions(-)
diff --git a/server.go b/server.go
@@ -69,7 +69,8 @@ type Server struct {
Auth func(context.Context, *Req)
}
-
+// NewServer creates a Server and runs listener and speaker goroutines.
+// It reads incoming messages from r and writes responses to w.
func NewServer(fsys FS, mSize uint32, r io.Reader, w io.Writer) *Server {
s := &Server{
fs: fsys,
@@ -83,20 +84,29 @@ func NewServer(fsys FS, mSize uint32, r io.Reader, w io.Writer) *Server {
return s
}
+// Chatty enables the server's log messages of 9P messages.
func (s *Server) Chatty() { s.chatty9P = true }
+// mSize reads the maximum message size of the server.
func (s *Server) mSize() uint32 {
s.mSizeLock.Lock()
defer s.mSizeLock.Unlock()
return s.msize
}
+// setMSize changes the server's maximum message size.
func (s *Server) setMSize(mSize uint32) {
s.mSizeLock.Lock()
defer s.mSizeLock.Unlock()
s.msize = mSize
}
+// runListener runs the listener goroutine.
+// Listener goroutine reads 9P messages from r and allocats Req for each
+// of them, and sends it to the returned chan of *Req.
+// It reports any error to the returned chan of error.
+// TODO: pass context.Context and stop the goroutine with the Context being
+// canceled.
func (s *Server) runListener(r io.Reader) (<-chan *Req, <-chan error) {
rc := make(chan *Req)
ec := make(chan error)
@@ -114,12 +124,17 @@ func (s *Server) runListener(r io.Reader) (<-chan *Req, <-chan error) {
return rc, ec
}
+// runSpeaker runs the speaker goroutine.
+// Speaker goroutine wait for reply Requests from the returned channel,
+// and marshalls each of them into 9P messages and writes it to w.
+// TODO: pass context.Context and stop the goroutine with the Context being
+// canceled.
func (s *Server) runSpeaker(w io.Writer) (chan<- *Req, <-chan error) {
rc := make(chan *Req, 3) // TODO: buffer size?
ec := make(chan error)
go func() {
// TODO: close rc anywhere
- defer close(ec) // I think this will never be called.
+ defer close(ec)
for {
r := <-rc
_, err := w.Write(r.ofcall.marshal())
@@ -177,7 +192,14 @@ func getReq(r io.Reader, s *Server) (*Req, error) {
return req, nil
}
-// TODO: abort all outstanding I/O on the same connection.
+// sVersion processes Tversion message.
+// It checks if the version string is "9P2000", and if the version differs from
+// that, it replies with version string "unknown".
+// It also checks the msize of the message and if it is bigger than that of the
+// server, it replies with msize being the server's mSize, otherwise it sets the
+// server's mSize to the message's one.
+// TODO: abort all outstanding I/O on the same connection before
+// serving new Tversion.
func sVersion(ctx context.Context, s *Server, r *Req) {
ifcall := r.ifcall.(*TVersion)
version := ifcall.Version()
@@ -197,6 +219,8 @@ func sVersion(ctx context.Context, s *Server, r *Req) {
respond(ctx, r, nil)
}
+// rVersion confirms that err is nil, and sets the server's msize to the
+// appropreate one.
func rVersion(r *Req, err error) {
if err != nil {
panic(fmt.Errorf("rVersion err: %w", err))
@@ -204,10 +228,10 @@ func rVersion(r *Req, err error) {
r.srv.setMSize(r.ofcall.(*RVersion).MSize())
}
+// sAuth serves Tauth message.
func sAuth(ctx context.Context, s *Server, r *Req) {
ifcall := r.ifcall.(*TAuth)
var err error
- // TODO: this call can block. need ctx?
r.afid, err = s.fPool.add(ifcall.AFid())
if err != nil {
respond(ctx, r, ErrDupFid)
@@ -220,6 +244,8 @@ func sAuth(ctx context.Context, s *Server, r *Req) {
}
}
+// rAuth checks if err is nil, and if not, it deletes the
+// allocated fid from fPool.
func rAuth(r *Req, err error) {
if err != nil {
r.srv.fPool.delete(r.ifcall.(*TAuth).AFid())
@@ -883,6 +909,7 @@ func rWStat(r *Req, err error) {
}
}
+// Serve serves 9P conversation.
func (s *Server) Serve(ctx context.Context) {
L:
for {
