// JailTail opens a file within this worker's jail directory and prepares a
// cross-circuit pointer to the open file
func (a *Acid) JailTail(jailFile string) (circuit.X, error) {
abs := path.Join(config.Config.Deploy.JailDir(), circuit.WorkerAddr().WorkerID().String(), jailFile)
cmd := exec.Command("/bin/sh", "-c", "tail -f "+abs)
stdout, err := cmd.StdoutPipe()
if err != nil {
return nil, circuit.FlattenError(err)
}
if err = cmd.Start(); err != nil {
return nil, circuit.FlattenError(err)
}
return circuit.Ref(teleio.NewServer(&tailStdout{stdout, cmd})), nil
}
func (srv *Server) Query(spaceID vena.SpaceID, minTime, maxTime vena.Time, stat vena.Stat, velocity bool) ([]*Point, error) {
if minTime >= maxTime {
return nil, nil
}
pivot := &RowKey{SpaceID: spaceID, Time: minTime}
iter := srv.Server.DB.NewIterator(srv.Server.ReadAndCache)
defer iter.Close()
iter.Seek(pivot.Encode())
if !iter.Valid() {
return nil, nil
}
const limit = 1e4 // Maximum number of result points
result := make([]*Point, 0, limit)
for len(result) < limit && iter.Valid() {
key, err := DecodeRowKey(iter.Key())
if err != nil {
return nil, circuit.FlattenError(err)
}
if key.SpaceID != spaceID || key.Time >= maxTime {
break
}
value, err := DecodeRowValue(iter.Value())
if err != nil {
return nil, circuit.FlattenError(err)
}
result = append(result, &Point{Time: key.Time, Value: value.Value})
iter.Next()
}
srv.rlk.Lock()
srv.nquery++
srv.rlk.Unlock()
return result, nil
}
func (srv *Server) Put(time vena.Time, spaceID vena.SpaceID, value float64) error {
rowKey := &RowKey{SpaceID: spaceID, Time: time}
rowValue := &RowValue{Value: value}
srv.wlk.Lock()
wopts := srv.WriteNoSync
if srv.nwrite%100 == 0 {
wopts = srv.WriteSync
}
srv.wlk.Unlock()
if err := srv.DB.Put(wopts, rowKey.Encode(), rowValue.Encode()); err != nil {
return circuit.FlattenError(err)
}
srv.wlk.Lock()
srv.nwrite++
srv.wlk.Unlock()
return nil
}
func (t *tailStdout) Close() error {
println("CLOSING TAIL")
err := t.ReadCloser.Close()
t.cmd.Process.Kill()
return circuit.FlattenError(err)
}