func (s *Session) handleTcreate(cx context.Context, msg styxproto.Tcreate, file file) bool {
qid := s.conn.qid(file.name, 0)
if qid.Type()&styxproto.QTDIR == 0 {
s.conn.clearTag(msg.Tag())
s.conn.Rerror(msg.Tag(), "not a directory: %q", file.name)
s.conn.Flush()
return true
}
s.requests <- Tcreate{
Name: string(msg.Name()),
Mode: styxfile.ModeOS(msg.Perm()),
Flag: openFlag(msg.Mode()),
reqInfo: newReqInfo(cx, s, msg, file.name),
}
return true
}
// The Ropen method signals to the client that a file has succesfully
// been opened and is ready for I/O. After Ropen returns, future reads
// and writes to the opened file handle will pass through rwc.
//
// The value rwc must implement some of the interfaces in the io package
// for reading and writing. If the type implements io.Seeker or io.ReaderAt
// and io.WriterAt, clients may read or write at arbitrary offsets within
// the file. Types that only implement Read or Write operations will return
// errors on writes and reads, respectively.
//
// If rwc implements the Stat method of os.File, that will be used to
// answer Tstat requests. Otherwise, the styx package will assemble Rstat
// responses out of default values merged with any methods rwc provides
// from the os.FileInfo interface.
//
// If a file does not implement any of the Read or Write interfaces in
// the io package, A generic error is returned to the client, and a message
// will be written to the server's ErrorLog.
func (t Topen) Ropen(rwc interface{}, err error) {
var (
file file
f styxfile.Interface
)
if err != nil {
t.Rerror("%s", err)
return
}
// The type of the file (regular or directory) will have been
// established in a previous Twalk request.
qid := t.session.conn.qid(t.Path(), 0)
mode := styxfile.ModeOS(uint32(qid.Type()) << 24)
if dir, ok := rwc.(Directory); ok && mode.IsDir() {
f = styxfile.NewDir(dir, t.Path(), t.session.conn.qidpool)
} else {
f, err = styxfile.New(rwc)
}
if err != nil {
t.session.conn.srv.logf("%s open %s failed: %s", t.path, err)
// Don't want to expose too many implementation details
// to clients.
t.Rerror("open failed")
return
}
t.session.files.Update(t.fid, &file, func() {
file.rwc = f
})
t.session.unhandled = false
if t.session.conn.clearTag(t.tag) {
t.session.conn.Ropen(t.tag, qid, 0)
}
}
func (s *Session) handleTwstat(cx context.Context, msg styxproto.Twstat, file file) bool {
// mode, atime+mtime, length, name, uid+gid, sync
// we will ignore muid
const numMutable = 6
// By convention, sending a Twstat message with a stat structure consisting
// entirely of "don't touch" values indicates that the client wants the server
// to sync the file to disk.
var haveChanges bool
var messages int
stat := msg.Stat()
// We buffer the channel so that the response
// methods for each attribute do not block.
status := make(chan error, numMutable)
info := newReqInfo(cx, s, msg, file.name)
filled := make([]int32, numMutable)
atime, mtime := stat.Atime(), stat.Mtime()
if atime != math.MaxUint32 || mtime != math.MaxUint32 {
haveChanges = true
s.requests <- Tutimes{
Atime: time.Unix(int64(atime), 0),
Mtime: time.Unix(int64(mtime), 0),
twstat: twstat{status, filled, messages, info},
}
messages++
}
if uid, gid := string(stat.Uid()), string(stat.Gid()); uid != "" || gid != "" {
haveChanges = true
s.requests <- Tchown{
User: uid,
Group: gid,
twstat: twstat{status, filled, messages, info},
}
messages++
}
if name := string(stat.Name()); name != "" && name != file.name {
haveChanges = true
s.requests <- Trename{
OldPath: file.name,
NewPath: name,
twstat: twstat{status, filled, messages, info},
}
messages++
}
if length := stat.Length(); length != -1 {
haveChanges = true
s.requests <- Ttruncate{
Size: length,
twstat: twstat{status, filled, messages, info},
}
messages++
}
if stat.Mode() != math.MaxUint32 {
haveChanges = true
s.requests <- Tchmod{
Mode: styxfile.ModeOS(stat.Mode()),
twstat: twstat{status, filled, messages, info},
}
messages++
}
if len(stat.Muid()) != 0 {
// even though we won't respond to this field, we don't
// want to needlessly stimulate a sync request
haveChanges = true
}
if !haveChanges {
s.requests <- Tsync{
twstat: twstat{status, filled, messages, info},
}
messages++
}
go func() {
var (
success bool
err error
)
for i := 0; i < messages; i++ {
if e, ok := <-status; !ok {
panic("closed Twstat channel prematurely")
} else if e != nil {
err = e
} else {
success = true
}
}
if !s.conn.clearTag(msg.Tag()) {
return
}
if success {
s.conn.Rwstat(msg.Tag())
} else {
s.conn.Rerror(msg.Tag(), "%s", err)
}
s.conn.Flush()
}()
return true
}