// fetchByFetchlist fetches the messages in the supplied fetchlist and sends them to the message-channel
func (p *messagePartition) fetchByFetchlist(fetchList *indexList, req *store.FetchRequest) error {
return fetchList.mapWithPredicate(func(index *index, _ int) error {
if req.IsDone() {
return store.ErrRequestDone
}
filename := p.composeMsgFilenameForPosition(uint64(index.fileID))
file, err := os.Open(filename)
if err != nil {
return err
}
defer file.Close()
msg := make([]byte, index.size, index.size)
_, err = file.ReadAt(msg, int64(index.offset))
if err != nil {
logger.WithFields(log.Fields{
"err": err,
"offset": index.offset,
}).Error("Error ReadAt")
return err
}
req.Push(index.id, msg)
return nil
})
}
