func (t *traverser) traverse(parent *g9pc.NsFile, path, name string, sync chan bool) {
sq, results := seq.NewSequencer()
doneWalk := make(chan bool)
go func() {
defer close(doneWalk)
if name != "" {
_, ok := <-results // SeqWalk
if !ok {
t.printf("cannot walk to %q: %v", path+"/"+name, sq.Error())
return
}
}
doneWalk <- true
<-results // readDir or readFile.
_, ok := <-results // eof.
if ok {
panic("expected closed")
}
}()
fid := parent
if name != "" {
fid = parent.SeqWalk(sq, name)
}
_, ok := <-doneWalk
if !ok {
return
}
sync <- true
t.printf("read %q, dir %v", path+"/"+name, fid.IsDir())
t.refc <- 1
go func() {
t.grab()
path += "/" + name
if fid.IsDir() {
t.readDir(sq, fid, path)
} else {
t.readFile(sq, fid, path)
}
sq.Do(nil, nil)
t.refc <- -1
t.release()
}()
}
func (t *traverser) readFile(sq *seq.Sequencer, fid *g9pc.NsFile, path string) {
t.printf("readFile %s", path)
sq, results := sq.Subsequencer("readFile")
go func() {
_, ok := <-results // open
if !ok {
t.printf("cannot open %s: %v", path, sq.Error())
return
}
<-results // stream
_, ok = <-results
if ok {
panic("expected closed")
}
sq.Result(seq.StringResult("readFile"), sq.Error())
}()
sq.Do(fid.File(), seq.OpenReq{g9p.OREAD})
rd := fid.SeqReadStream(sq, 20, 8192)
tot, _ := io.Copy(nullWriter{}, rd)
t.printf("%10d %s", tot, path)
sq.Do(nil, nil)
}
func (t *traverser) readDir(pseq *seq.Sequencer, fid *g9pc.NsFile, path string) {
t.printf("readDir %s", path)
sq, results := pseq.Subsequencer("readDir")
errc := make(chan error, 1)
go func() {
<-results // SeqWalk (clone)
_, ok := <-results // OpenReq
if !ok {
errc <- fmt.Errorf("cannot open %q: %#v", path, sq.Error())
return
}
<-results // NonseqReq
<-results // ReadStream
errc <- nil
_, ok = <-results // eof
if ok {
panic("expected closed")
}
errc <- nil
}()
rfid := fid.SeqWalk(sq)
// defer rfid.Close() TODO something better!
sq.Do(rfid.File(), seq.OpenReq{g9p.OREAD})
sq.Do(fid.File(), seq.NonseqReq{})
rd := rfid.SeqReadStream(sq, 5, 8192)
defer rd.Close()
buf, _ := ioutil.ReadAll(rd)
t.printf("read %d bytes from %q", len(buf), path)
err := <-errc
sq.Do(nil, nil)
<-errc
//we get here but fid still can be part of the sequence.
//maybe that means that subsequence has not terminated
//correctly. no it doesn't. it means that the overall sequence
//has not terminated correctly.
//
//question: should files opened as part of a subsequence be
//ratified by the subsequence finishing?
//only
if err != nil && len(buf) == 0 {
sq.Result(nil, err)
t.printf("error on %s: %v\n", path, err)
return
}
d, err := g9p.UnmarshalDirs(buf)
if err != nil {
t.printf("cannot unpack directory %s: %v\n", path, err)
return
}
sync := make(chan bool)
for i, dir := range d {
t.printf("%q[%d]: %v", path, i, dir)
go t.traverse(fid, path, dir.Name, sync)
}
for i := 0; i < len(d); i++ {
<-sync
}
t.printf("%s: %d entries", path, len(d))
sq.Result(seq.StringResult("readDir"), nil)
}