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
}
