func (self *httpBackendStream) Read(from uint, to uint) (stream.Stream, error) {
if from == to {
return stream.Empty(), nil
}
resp, err := self.p.Post(fmt.Sprintf(self.readUrl, from, to), nil)
if err != nil {
return nil, err
}
defer resp.Body.Close()
res := arrErrorObj{}
if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
return nil, err
}
if res.Err != "" {
return nil, errors.New(res.Err)
}
r := make([]stream.Event, len(res.Events))
for i, v := range res.Events {
r[i] = stream.Event([]byte(v))
}
return stream.List(r), nil
}
func (self *memStreamObj) Read(from uint, to uint) (stream.Stream, error) {
if from == to {
return stream.Empty(), nil
}
self.lock.Lock()
defer self.lock.Unlock()
l := len(self.data)
if _, _, err := convRange(int(from), int(to), l, "memStreamObj.Read"); err != nil {
return nil, err
}
return stream.List(self.data[from:to]), nil
}
func (self *dirStreamObj) Read(from uint, to uint) (sres stream.Stream, rerr error) {
if from == to {
return stream.Empty(), nil
}
self.lock.Lock()
defer self.lock.Unlock()
l, err := self.slen()
if err != nil {
return nil, err
}
if _, _, err := convRange(int(from), int(to), int(l), "dirStreamObj.Read"); err != nil {
return nil, err
}
res := []stream.Event{}
file, err := os.Open(self.back.dir + "/" + self.name)
if err != nil {
return nil, err
}
defer func() {
rerr = errors.List().Add(rerr).Add(file.Close()).Err()
if rerr != nil {
sres = nil
}
}()
scanner := bufio.NewScanner(file)
lineNum := uint(0)
for scanner.Scan() {
if lineNum >= from && lineNum < to {
res = append(res, scanner.Bytes())
}
lineNum++
}
if err := scanner.Err(); err != nil {
return nil, err
}
return stream.List(res), nil
}