Golang Key.DsKey方法代碼示例

func (d *datastoreBlockSet) AddBlock(k key.Key) {
	err := d.dstore.Put(k.DsKey(), []byte{})
	if err != nil {
		log.Debugf("blockset put error: %s", err)
	}

	d.bset.AddBlock(k)
}

func putRoutingRecord(ds datastore.Datastore, k key.Key, value *dhtpb.Record) error {
	data, err := proto.Marshal(value)
	if err != nil {
		return err
	}
	dskey := k.DsKey()
	// TODO namespace
	if err := ds.Put(dskey, data); err != nil {
		return err
	}
	return nil
}

func getRoutingRecord(ds datastore.Datastore, k key.Key) (*dhtpb.Record, error) {
	dskey := k.DsKey()
	val, err := ds.Get(dskey)
	if err != nil {
		return nil, err
	}
	recordBytes, ok := val.([]byte)
	if !ok {
		return nil, fmt.Errorf("datastore had non byte-slice value for %v", dskey)
	}
	var record dhtpb.Record
	if err := proto.Unmarshal(recordBytes, &record); err != nil {
		return nil, errors.New("failed to unmarshal dht record from datastore")
	}
	return &record, nil
}

// getLocal attempts to retrieve the value from the datastore
func (dht *IpfsDHT) getLocal(key key.Key) (*pb.Record, error) {

	log.Debug("getLocal %s", key)
	v, err := dht.datastore.Get(key.DsKey())
	if err != nil {
		return nil, err
	}
	log.Debug("found in db")

	byt, ok := v.([]byte)
	if !ok {
		return nil, errors.New("value stored in datastore not []byte")
	}
	rec := new(pb.Record)
	err = proto.Unmarshal(byt, rec)
	if err != nil {
		return nil, err
	}

	err = dht.verifyRecordLocally(rec)
	if err != nil {
		log.Debugf("local record verify failed: %s (discarded)", err)
		return nil, err
	}

	return rec, nil
}

// putLocal stores the key value pair in the datastore
func (dht *IpfsDHT) putLocal(key key.Key, rec *pb.Record) error {
	data, err := proto.Marshal(rec)
	if err != nil {
		return err
	}

	return dht.datastore.Put(key.DsKey(), data)
}

func (p *ipnsPublisher) getPreviousSeqNo(ctx context.Context, ipnskey key.Key) (uint64, error) {
	prevrec, err := p.ds.Get(ipnskey.DsKey())
	if err != nil && err != ds.ErrNotFound {
		// None found, lets start at zero!
		return 0, err
	}
	var val []byte
	if err == nil {
		prbytes, ok := prevrec.([]byte)
		if !ok {
			return 0, fmt.Errorf("unexpected type returned from datastore: %#v", prevrec)
		}
		dhtrec := new(dhtpb.Record)
		err := proto.Unmarshal(prbytes, dhtrec)
		if err != nil {
			return 0, err
		}

		val = dhtrec.GetValue()
	} else {
		// try and check the dht for a record
		ctx, cancel := context.WithTimeout(ctx, time.Second*30)
		defer cancel()

		rv, err := p.routing.GetValue(ctx, ipnskey)
		if err != nil {
			// no such record found, start at zero!
			return 0, nil
		}

		val = rv
	}

	e := new(pb.IpnsEntry)
	err = proto.Unmarshal(val, e)
	if err != nil {
		return 0, err
	}

	return e.GetSequence(), nil
}

func (c *offlineRouting) PutValue(ctx context.Context, key key.Key, val []byte) error {
	rec, err := record.MakePutRecord(c.sk, key, val, false)
	if err != nil {
		return err
	}
	data, err := proto.Marshal(rec)
	if err != nil {
		return err
	}

	return c.datastore.Put(key.DsKey(), data)
}

// FIXME(brian): is this method meant to simulate putting a value into the network?
func (c *client) PutValue(ctx context.Context, key key.Key, val []byte) error {
	log.Debugf("PutValue: %s", key)
	rec := new(dhtpb.Record)
	rec.Value = val
	rec.Key = proto.String(string(key))
	rec.TimeReceived = proto.String(u.FormatRFC3339(time.Now()))
	data, err := proto.Marshal(rec)
	if err != nil {
		return err
	}

	return c.datastore.Put(key.DsKey(), data)
}

func (rp *Republisher) getLastVal(k key.Key) (path.Path, uint64, error) {
	ival, err := rp.ds.Get(k.DsKey())
	if err != nil {
		// not found means we dont have a previously published entry
		return "", 0, errNoEntry
	}

	val := ival.([]byte)
	dhtrec := new(dhtpb.Record)
	err = proto.Unmarshal(val, dhtrec)
	if err != nil {
		return "", 0, err
	}

	// extract published data from record
	e := new(pb.IpnsEntry)
	err = proto.Unmarshal(dhtrec.GetValue(), e)
	if err != nil {
		return "", 0, err
	}
	return path.Path(e.Value), e.GetSequence(), nil
}

func (c *offlineRouting) GetValue(ctx context.Context, key key.Key) ([]byte, error) {
	v, err := c.datastore.Get(key.DsKey())
	if err != nil {
		return nil, err
	}

	byt, ok := v.([]byte)
	if !ok {
		return nil, errors.New("value stored in datastore not []byte")
	}
	rec := new(pb.Record)
	err = proto.Unmarshal(byt, rec)
	if err != nil {
		return nil, err
	}

	return rec.GetValue(), nil
}

// FIXME(brian): is this method meant to simulate getting a value from the network?
func (c *client) GetValue(ctx context.Context, key key.Key) ([]byte, error) {
	log.Debugf("GetValue: %s", key)
	v, err := c.datastore.Get(key.DsKey())
	if err != nil {
		return nil, err
	}

	data, ok := v.([]byte)
	if !ok {
		return nil, errors.New("could not cast value from datastore")
	}

	rec := new(dhtpb.Record)
	err = proto.Unmarshal(data, rec)
	if err != nil {
		return nil, err
	}

	return rec.GetValue(), nil
}

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
}

func (d *datastoreBlockSet) RemoveBlock(k key.Key) {
	d.bset.RemoveBlock(k)
	if !d.bset.HasKey(k) {
		d.dstore.Delete(k.DsKey())
	}
}