*: proto refactoring

etcdserver/etcdserverpb/etcdserver.pb.go

@@ -10,7 +10,7 @@
 
 	It has these top-level messages:
 		Request
-		Info
+		Metadata
 */
 package etcdserverpb
 
@@ -52,14 +52,14 @@ func (m *Request) Reset()         { *m = Request{} }
 func (m *Request) String() string { return proto.CompactTextString(m) }
 func (*Request) ProtoMessage()    {}
 
-type Info struct {
+type Metadata struct {
-	ID               uint64 `protobuf:"varint,1,req" json:"ID"`
+	NodeID           uint64 `protobuf:"varint,1,req" json:"NodeID"`
 	XXX_unrecognized []byte `json:"-"`
 }
 
-func (m *Info) Reset()         { *m = Info{} }
+func (m *Metadata) Reset()         { *m = Metadata{} }
-func (m *Info) String() string { return proto.CompactTextString(m) }
+func (m *Metadata) String() string { return proto.CompactTextString(m) }
-func (*Info) ProtoMessage()    {}
+func (*Metadata) ProtoMessage()    {}
 
 func init() {
 }
@@ -388,7 +388,7 @@ func (m *Request) Unmarshal(data []byte) error {
 	}
 	return nil
 }
-func (m *Info) Unmarshal(data []byte) error {
+func (m *Metadata) Unmarshal(data []byte) error {
 	l := len(data)
 	index := 0
 	for index < l {
@@ -417,7 +417,7 @@ func (m *Info) Unmarshal(data []byte) error {
 				}
 				b := data[index]
 				index++
-				m.ID |= (uint64(b) & 0x7F) << shift
+				m.NodeID |= (uint64(b) & 0x7F) << shift
 				if b < 0x80 {
 					break
 				}
@@ -475,10 +475,10 @@ func (m *Request) Size() (n int) {
 	}
 	return n
 }
-func (m *Info) Size() (n int) {
+func (m *Metadata) Size() (n int) {
 	var l int
 	_ = l
-	n += 1 + sovEtcdserver(uint64(m.ID))
+	n += 1 + sovEtcdserver(uint64(m.NodeID))
 	if m.XXX_unrecognized != nil {
 		n += len(m.XXX_unrecognized)
 	}
@@ -609,7 +609,7 @@ func (m *Request) MarshalTo(data []byte) (n int, err error) {
 	}
 	return i, nil
 }
-func (m *Info) Marshal() (data []byte, err error) {
+func (m *Metadata) Marshal() (data []byte, err error) {
 	size := m.Size()
 	data = make([]byte, size)
 	n, err := m.MarshalTo(data)
@@ -619,14 +619,14 @@ func (m *Info) Marshal() (data []byte, err error) {
 	return data[:n], nil
 }
 
-func (m *Info) MarshalTo(data []byte) (n int, err error) {
+func (m *Metadata) MarshalTo(data []byte) (n int, err error) {
 	var i int
 	_ = i
 	var l int
 	_ = l
 	data[i] = 0x8
 	i++
-	i = encodeVarintEtcdserver(data, i, uint64(m.ID))
+	i = encodeVarintEtcdserver(data, i, uint64(m.NodeID))
 	if m.XXX_unrecognized != nil {
 		i += copy(data[i:], m.XXX_unrecognized)
 	}

etcdserver/etcdserverpb/etcdserver.proto

@@ -26,6 +26,6 @@ message Request {
 	required bool   Stream     = 16 [(gogoproto.nullable) = false];
 }
 
-message Info {
+message Metadata {
-	required uint64 ID   = 1 [(gogoproto.nullable) = false];
+	required uint64 NodeID   = 1 [(gogoproto.nullable) = false];
 }

etcdserver/server.go

@@ -12,6 +12,7 @@ import (
 	"github.com/coreos/etcd/Godeps/_workspace/src/code.google.com/p/go.net/context"
 	"github.com/coreos/etcd/discovery"
 	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+	"github.com/coreos/etcd/pkg/pbutil"
 	"github.com/coreos/etcd/raft"
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/snap"
@@ -384,11 +385,7 @@ func (s *EtcdServer) sync(timeout time.Duration) {
 		ID:     GenID(),
 		Time:   time.Now().UnixNano(),
 	}
-	data, err := req.Marshal()
+	data := pbutil.MustMarshal(&req)
-	if err != nil {
-		log.Printf("marshal request %#v error: %v", req, err)
-		return
-	}
 	// There is no promise that node has leader when do SYNC request,
 	// so it uses goroutine to propose.
 	go func() {
@@ -447,15 +444,11 @@ func (s *EtcdServer) apply(es []raftpb.Entry) uint64 {
 		switch e.Type {
 		case raftpb.EntryNormal:
 			var r pb.Request
-			if err := r.Unmarshal(e.Data); err != nil {
+			pbutil.MustUnmarshal(&r, e.Data)
-				panic("TODO: this is bad, what do we do about it?")
-			}
 			s.w.Trigger(r.ID, s.applyRequest(r))
 		case raftpb.EntryConfChange:
 			var cc raftpb.ConfChange
-			if err := cc.Unmarshal(e.Data); err != nil {
+			pbutil.MustUnmarshal(&cc, e.Data)
-				panic("TODO: this is bad, what do we do about it?")
-			}
 			s.applyConfChange(cc)
 			s.w.Trigger(cc.ID, nil)
 		default:
@@ -541,12 +534,9 @@ func (s *EtcdServer) snapshot(snapi uint64, snapnodes []uint64) {
 }
 
 func startNode(cfg *ServerConfig) (n raft.Node, w *wal.WAL) {
-	i := pb.Info{ID: cfg.ID()}
+	var err error
-	b, err := i.Marshal()
+	metadata := pbutil.MustMarshal(&pb.Metadata{NodeID: cfg.ID()})
-	if err != nil {
+	if w, err = wal.Create(cfg.WALDir(), metadata); err != nil {
-		log.Fatal(err)
-	}
-	if w, err = wal.Create(cfg.WALDir(), b); err != nil {
 		log.Fatal(err)
 	}
 	ids := cfg.Cluster.IDs()
@@ -568,15 +558,15 @@ func restartNode(cfg *ServerConfig, index uint64, snapshot *raftpb.Snapshot) (n
 	if w, err = wal.OpenAtIndex(cfg.WALDir(), index); err != nil {
 		log.Fatal(err)
 	}
-	md, st, ents, err := w.ReadAll()
+	wmetadata, st, ents, err := w.ReadAll()
 	if err != nil {
 		log.Fatal(err)
 	}
-	var info pb.Info
+
-	if err := info.Unmarshal(md); err != nil {
+	var metadata pb.Metadata
-		log.Fatal(err)
+	pbutil.MustUnmarshal(&metadata, wmetadata)
-	}
+
-	n = raft.RestartNode(info.ID, 10, 1, snapshot, st, ents)
+	n = raft.RestartNode(metadata.NodeID, 10, 1, snapshot, st, ents)
 	return
 }
 

pkg/pbutil/pbutil.go

@@ -0,0 +1,25 @@
+package pbutil
+
+import "log"
+
+type Marshaler interface {
+	Marshal() (data []byte, err error)
+}
+
+type Unmarshaler interface {
+	Unmarshal(data []byte) error
+}
+
+func MustMarshal(m Marshaler) []byte {
+	d, err := m.Marshal()
+	if err != nil {
+		log.Panicf("pbutil: %v", err)
+	}
+	return d
+}
+
+func MustUnmarshal(um Unmarshaler, data []byte) {
+	if err := um.Unmarshal(data); err != nil {
+		log.Panicf("pbutil: %v", err)
+	}
+}

wal/decoder.go

@@ -7,6 +7,7 @@ import (
 	"io"
 
 	"github.com/coreos/etcd/pkg/crc"
+	"github.com/coreos/etcd/pkg/pbutil"
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/wal/walpb"
 )
@@ -60,19 +61,13 @@ func (d *decoder) close() error {
 
 func mustUnmarshalEntry(d []byte) raftpb.Entry {
 	var e raftpb.Entry
-	if err := e.Unmarshal(d); err != nil {
+	pbutil.MustUnmarshal(&e, d)
-		// crc matched, but we cannot unmarshal the struct?!
-		// we must be the next winner of the $1B lottery.
-		panic(err)
-	}
 	return e
 }
 
 func mustUnmarshalState(d []byte) raftpb.HardState {
 	var s raftpb.HardState
-	if err := s.Unmarshal(d); err != nil {
+	pbutil.MustUnmarshal(&s, d)
-		panic(err)
-	}
 	return s
 }
 

wal/wal.go

@@ -26,6 +26,7 @@ import (
 	"reflect"
 	"sort"
 
+	"github.com/coreos/etcd/pkg/pbutil"
 	"github.com/coreos/etcd/raft"
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/wal/walpb"
@@ -56,7 +57,7 @@ var (
 // The WAL will be ready for appending after reading out all the previous records.
 type WAL struct {
 	dir      string // the living directory of the underlay files
-	md  []byte // metadata recorded at the head of each WAL
+	metadata []byte // metadata recorded at the head of each WAL
 
 	ri      uint64   // index of entry to start reading
 	decoder *decoder // decoder to decode records
@@ -85,7 +86,7 @@ func Create(dirpath string, metadata []byte) (*WAL, error) {
 	}
 	w := &WAL{
 		dir:      dirpath,
-		md:      metadata,
+		metadata: metadata,
 		seq:      0,
 		f:        f,
 		encoder:  newEncoder(f, 0),
@@ -208,7 +209,7 @@ func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.
 	w.decoder.close()
 	w.ri = 0
 
-	w.md = metadata
+	w.metadata = metadata
 	// create encoder (chain crc with the decoder), enable appending
 	w.encoder = newEncoder(w.f, w.decoder.lastCRC())
 	w.decoder = nil
@@ -234,7 +235,7 @@ func (w *WAL) Cut() error {
 	if err := w.saveCrc(prevCrc); err != nil {
 		return err
 	}
-	return w.encoder.encode(&walpb.Record{Type: metadataType, Data: w.md})
+	return w.encoder.encode(&walpb.Record{Type: metadataType, Data: w.metadata})
 }
 
 func (w *WAL) Sync() error {
@@ -254,10 +255,7 @@ func (w *WAL) Close() {
 }
 
 func (w *WAL) SaveEntry(e *raftpb.Entry) error {
-	b, err := e.Marshal()
+	b := pbutil.MustMarshal(e)
-	if err != nil {
-		panic(err)
-	}
 	rec := &walpb.Record{Type: entryType, Data: b}
 	if err := w.encoder.encode(rec); err != nil {
 		return err
@@ -270,10 +268,7 @@ func (w *WAL) SaveState(s *raftpb.HardState) error {
 	if raft.IsEmptyHardState(*s) {
 		return nil
 	}
-	b, err := s.Marshal()
+	b := pbutil.MustMarshal(s)
-	if err != nil {
-		panic(err)
-	}
 	rec := &walpb.Record{Type: stateType, Data: b}
 	return w.encoder.encode(rec)
 }