func applyCompaction(kv mvcc.KV, req *etcdserverpb.CompactionRequest) (*etcdserverpb.CompactionResponse, error) { resp := &etcdserverpb.CompactionResponse{} resp.Header = &etcdserverpb.ResponseHeader{} _, err := kv.Compact(req.Revision) if err != nil { return nil, err } // get the current revision. which key to get is not important. _, resp.Header.Revision, _ = kv.Range([]byte("compaction"), nil, 1, 0) return resp, err }