Golang proto.Unmarshal函数代码示例

// 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
}

// NewDagReader creates a new reader object that reads the data represented by
// the given node, using the passed in DAGService for data retreival
func NewDagReader(ctx context.Context, n *mdag.Node, serv mdag.DAGService) (*DagReader, error) {
	pb := new(ftpb.Data)
	if err := proto.Unmarshal(n.Data, pb); err != nil {
		return nil, err
	}

	switch pb.GetType() {
	case ftpb.Data_Directory:
		// Dont allow reading directories
		return nil, ErrIsDir
	case ftpb.Data_Raw:
		fallthrough
	case ftpb.Data_File:
		return NewDataFileReader(ctx, n, pb, serv), nil
	case ftpb.Data_Metadata:
		if len(n.Links) == 0 {
			return nil, errors.New("incorrectly formatted metadata object")
		}
		child, err := n.Links[0].GetNode(ctx, serv)
		if err != nil {
			return nil, err
		}
		return NewDagReader(ctx, child, serv)
	case ftpb.Data_Symlink:
		return nil, ErrCantReadSymlinks
	default:
		return nil, ft.ErrUnrecognizedType
	}
}

func TestPBLinkMarshalTo(t *testing.T) {
	popr := math_rand.New(math_rand.NewSource(time.Now().UnixNano()))
	p := NewPopulatedPBLink(popr, false)
	size := p.Size()
	data := make([]byte, size)
	for i := range data {
		data[i] = byte(popr.Intn(256))
	}
	_, err := p.MarshalTo(data)
	if err != nil {
		panic(err)
	}
	msg := &PBLink{}
	if err := github_com_gogo_protobuf_proto.Unmarshal(data, msg); err != nil {
		panic(err)
	}
	for i := range data {
		data[i] = byte(popr.Intn(256))
	}
	if err := p.VerboseEqual(msg); err != nil {
		t.Fatalf("%#v !VerboseProto %#v, since %v", msg, p, err)
	}
	if !p.Equal(msg) {
		t.Fatalf("%#v !Proto %#v", msg, p)
	}
}

func readHdr(n *merkledag.ProtoNode) (*pb.Set, error) {
	hdrLenRaw, consumed := binary.Uvarint(n.Data())
	if consumed <= 0 {
		return nil, errors.New("invalid Set header length")
	}

	pbdata := n.Data()[consumed:]
	if hdrLenRaw > uint64(len(pbdata)) {
		return nil, errors.New("impossibly large Set header length")
	}
	// as hdrLenRaw was <= an int, we now know it fits in an int
	hdrLen := int(hdrLenRaw)
	var hdr pb.Set
	if err := proto.Unmarshal(pbdata[:hdrLen], &hdr); err != nil {
		return nil, err
	}

	if v := hdr.GetVersion(); v != 1 {
		return nil, fmt.Errorf("unsupported Set version: %d", v)
	}
	if uint64(hdr.GetFanout()) > uint64(len(n.Links())) {
		return nil, errors.New("impossibly large Fanout")
	}
	return &hdr, nil
}

func readMsgCtx(ctx context.Context, r msgio.Reader, p proto.Message) ([]byte, error) {
	var msg []byte

	// read in a goroutine so we can exit when our context is cancelled.
	done := make(chan error)
	go func() {
		var err error
		msg, err = r.ReadMsg()
		select {
		case done <- err:
		case <-ctx.Done():
		}
	}()

	select {
	case <-ctx.Done():
		return nil, ctx.Err()
	case e := <-done:
		if e != nil {
			return nil, e
		}
	}

	return msg, proto.Unmarshal(msg, p)
}

func TestFSNode(t *testing.T) {
	fsn := new(FSNode)
	fsn.Type = TFile
	for i := 0; i < 15; i++ {
		fsn.AddBlockSize(100)
	}

	fsn.Data = make([]byte, 128)

	b, err := fsn.GetBytes()
	if err != nil {
		t.Fatal(err)
	}

	pbn := new(pb.Data)
	err = proto.Unmarshal(b, pbn)
	if err != nil {
		t.Fatal(err)
	}

	ds, err := DataSize(b)
	if err != nil {
		t.Fatal(err)
	}

	if ds != (100*15)+128 {
		t.Fatal("Datasize calculations incorrect!")
	}
}

func FromBytes(data []byte) (*pb.Data, error) {
	pbdata := new(pb.Data)
	err := proto.Unmarshal(data, pbdata)
	if err != nil {
		return nil, err
	}
	return pbdata, nil
}

func UnwrapData(data []byte) ([]byte, error) {
	pbdata := new(pb.Data)
	err := proto.Unmarshal(data, pbdata)
	if err != nil {
		return nil, err
	}
	return pbdata.GetData(), nil
}

//MetadataFromBytes Unmarshals a protobuf message into Metadata.
func MetadataFromBytes(b []byte) (*Metadata, error) {
	pbd := new(pb.Data)
	err := proto.Unmarshal(b, pbd)
	if err != nil {
		return nil, err
	}
	if pbd.GetType() != pb.Data_Metadata {
		return nil, errors.New("incorrect node type")
	}

	pbm := new(pb.Metadata)
	err = proto.Unmarshal(pbd.Data, pbm)
	if err != nil {
		return nil, err
	}
	md := new(Metadata)
	md.MimeType = pbm.GetMimeType()
	return md, nil
}

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 (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 FSNodeFromBytes(b []byte) (*FSNode, error) {
	pbn := new(pb.Data)
	err := proto.Unmarshal(b, pbn)
	if err != nil {
		return nil, err
	}

	n := new(FSNode)
	n.Data = pbn.Data
	n.blocksizes = pbn.Blocksizes
	n.subtotal = pbn.GetFilesize() - uint64(len(n.Data))
	n.Type = pbn.GetType()
	return n, nil
}

func IpnsSelectorFunc(k key.Key, vals [][]byte) (int, error) {
	var recs []*pb.IpnsEntry
	for _, v := range vals {
		e := new(pb.IpnsEntry)
		err := proto.Unmarshal(v, e)
		if err == nil {
			recs = append(recs, e)
		} else {
			recs = append(recs, nil)
		}
	}

	return selectRecord(recs, vals)
}

func getRoutingProviders(ds datastore.Datastore, k key.Key) ([]*dhtpb.Message_Peer, error) {
	e := log.EventBegin(context.Background(), "getProviders", &k)
	defer e.Done()
	var providers []*dhtpb.Message_Peer
	if v, err := ds.Get(providerKey(k)); err == nil {
		if data, ok := v.([]byte); ok {
			var msg dhtpb.Message
			if err := proto.Unmarshal(data, &msg); err != nil {
				return nil, err
			}
			providers = append(providers, msg.GetProviderPeers()...)
		}
	}
	return providers, nil
}

func TestPBNodeVerboseEqual(t *testing.T) {
	popr := math_rand.New(math_rand.NewSource(time.Now().UnixNano()))
	p := NewPopulatedPBNode(popr, false)
	data, err := github_com_gogo_protobuf_proto.Marshal(p)
	if err != nil {
		panic(err)
	}
	msg := &PBNode{}
	if err := github_com_gogo_protobuf_proto.Unmarshal(data, msg); err != nil {
		panic(err)
	}
	if err := p.VerboseEqual(msg); err != nil {
		t.Fatalf("%#v !VerboseEqual %#v, since %v", msg, p, err)
	}
}