// CompactVolume compact a super block to another file.
func (s *Store) CompactVolume(id int32) (err error) {
var (
v, nv *volume.Volume
bdir, idir string
)
// try check volume
if v = s.Volumes[id]; v != nil {
if v.Compact {
return errors.ErrVolumeInCompact
}
} else {
return errors.ErrVolumeExist
}
// find a free volume
if nv, err = s.freeVolume(id); err != nil {
return
}
log.Infof("start compact volume: (%d) %s to %s", id, v.Block.File, nv.Block.File)
// no lock here, Compact is no side-effect
if err = v.StartCompact(nv); err != nil {
nv.Destroy()
v.StopCompact(nil)
return
}
s.vlock.Lock()
if v = s.Volumes[id]; v != nil {
log.Infof("stop compact volume: (%d) %s to %s", id, v.Block.File, nv.Block.File)
if err = v.StopCompact(nv); err == nil {
// WARN no need update volumes map, use same object, only update
// zookeeper the local index cause the block and index file changed.
if err = s.saveVolumeIndex(); err == nil {
err = s.zk.SetVolume(id, v.Meta())
}
if err != nil {
log.Errorf("compact volume: %d error(%v), local index or zookeeper index may save failed", id, err)
}
}
} else {
// never happen
err = errors.ErrVolumeExist
log.Errorf("compact volume: %d not exist(may bug)", id)
}
s.vlock.Unlock()
// WARN if failed, nv is free volume, if succeed nv replace with v.
// Sleep untill anyone had old volume variables all processed.
time.Sleep(_compactSleep)
nv.Destroy()
if err == nil {
bdir, idir = filepath.Dir(nv.Block.File), filepath.Dir(nv.Indexer.File)
_, err = s.AddFreeVolume(1, bdir, idir)
}
return
}
