func (s *Session) handleTwalk(cx context.Context, msg styxproto.Twalk, file file) bool {
newfid := msg.Newfid()
// Cannot use "opened" (ready for IO) fids for walking; see walk(5)
// in 9P manual. However, 9pfuse does this, so we'll allow it.
//if file.rwc != nil {
// s.conn.Rerror(msg.Tag(), "walk on opened fid")
// s.conn.Flush()
// return true
//}
// newfid must be unused or equal to fid
if newfid != msg.Fid() {
if _, ok := s.conn.sessionFid.Get(newfid); ok {
s.conn.clearTag(msg.Tag())
s.conn.Rerror(msg.Tag(), "Twalk: fid %x already in use", newfid)
s.conn.Flush()
return true
}
}
// NOTE(droyo) The clone usage of Twalk is hidden from the user
// of the styx package; we assume that all clients who have procured
// a fid for a file are permitted to clone that fid, and may do so without
// side effects.
if msg.Nwname() == 0 {
if newfid != msg.Fid() {
s.files.Put(newfid, file)
s.conn.sessionFid.Put(newfid, s)
s.IncRef()
}
s.conn.clearTag(msg.Tag())
s.conn.Rwalk(msg.Tag())
s.conn.Flush()
return true
}
// see walk.go for more details
elem := make([]string, 0, msg.Nwname())
for i := 0; i < cap(elem); i++ {
elem = append(elem, string(msg.Wname(i)))
}
walker := newWalker(s, cx, msg, file.name, elem...)
for i := range elem {
fullpath := path.Join(file.name, strings.Join(elem[:i+1], "/"))
s.requests <- Twalk{
index: i,
walk: walker,
reqInfo: newReqInfo(cx, s, msg, fullpath),
}
}
return true
}
func newWalker(s *Session, cx context.Context, msg styxproto.Twalk, base string, elem ...string) *walker {
qids := make([]styxproto.Qid, len(elem))
found := qids[:0]
newpath := path.Join(base, strings.Join(elem, "/"))
w := &walker{
qids: qids,
found: found,
filled: make([]int32, len(elem)),
complete: make(chan struct{}),
collect: make(chan walkElem),
session: s,
newfid: msg.Newfid(),
path: newpath,
tag: msg.Tag(),
cx: cx,
}
go w.run()
return w
}