func (dht *IpfsDHT) checkLocalDatastore(k key.Key) (*pb.Record, error) { log.Debugf("%s handleGetValue looking into ds", dht.self) dskey := k.DsKey() iVal, err := dht.datastore.Get(dskey) log.Debugf("%s handleGetValue looking into ds GOT %v", dht.self, iVal) if err == ds.ErrNotFound { return nil, nil } // if we got an unexpected error, bail. if err != nil { return nil, err } // if we have the value, send it back log.Debugf("%s handleGetValue success!", dht.self) byts, ok := iVal.([]byte) if !ok { return nil, fmt.Errorf("datastore had non byte-slice value for %v", dskey) } rec := new(pb.Record) err = proto.Unmarshal(byts, rec) if err != nil { log.Debug("Failed to unmarshal dht record from datastore") return nil, err } // if its our record, dont bother checking the times on it if peer.ID(rec.GetAuthor()) == dht.self { return rec, nil } var recordIsBad bool recvtime, err := u.ParseRFC3339(rec.GetTimeReceived()) if err != nil { log.Info("either no receive time set on record, or it was invalid: ", err) recordIsBad = true } if time.Now().Sub(recvtime) > MaxRecordAge { log.Debug("old record found, tossing.") recordIsBad = true } // NOTE: we do not verify the record here beyond checking these timestamps. // we put the burden of checking the records on the requester as checking a record // may be computationally expensive if recordIsBad { err := dht.datastore.Delete(dskey) if err != nil { log.Error("Failed to delete bad record from datastore: ", err) } return nil, nil // can treat this as not having the record at all } return rec, nil }