add position to log_entry protobuf

log.go

@@ -154,21 +154,20 @@ func (l *Log) open(path string) error {
 			l.file, err = os.OpenFile(path, os.O_WRONLY|os.O_CREATE, 0600)
 			debugln("log.open.create ", path)
 			if err != nil {
-				panic(err)
+				return err
 			}
 			// set commitIndex to 0
 			_, err = fmt.Fprintf(l.file, "%8x\n", 0)
 
 			if err != nil {
 				l.file.Close()
-				panic(err)
-				return err
 			}
-
+			return err
 		}
 		return err
 	}
 	debugln("log.open.exist ", path)
+
 	// if the log file exists
 	// we read out the commitIndex and apply all the commands
 	// seek to the end of log file
@@ -192,8 +191,6 @@ func (l *Log) open(path string) error {
 		entry, _ := newLogEntry(l, 0, 0, nil)
 		n, err := entry.decode(reader)
 		if err != nil {
-			//panic(err)
-			//l.file.Close()
 			if err = os.Truncate(path, readBytes); err != nil {
 				return fmt.Errorf("raft.Log: Unable to recover: %v", err)
 			}
@@ -203,6 +200,7 @@ func (l *Log) open(path string) error {
 		// Append entry.
 		l.entries = append(l.entries, entry)
 		debugln("open.log.append log index ", entry.Index)
+
 		// if the entry index less than the known commitIndex
 		// commit it
 		if entry.Index < commitIndex {

log_entry.go

@@ -58,6 +58,7 @@ func (e *LogEntry) encode(w io.Writer) (int, error) {
 		Term:        proto.Uint64(e.Term),
 		CommandName: proto.String(e.CommandName),
 		Command:     e.Command,
+		Position:    proto.Int64(e.Position),
 	}
 
 	err := p.Marshal(pb)
@@ -106,6 +107,7 @@ func (e *LogEntry) decode(r io.Reader) (int, error) {
 	e.Index = pb.GetIndex()
 	e.CommandName = pb.GetCommandName()
 	e.Command = pb.Command
+	e.Position = pb.GetPosition()
 
 	return length, nil
 }

log_test.go

@@ -168,7 +168,7 @@ func TestLogTruncate(t *testing.T) {
 	if err := log.open(path); err != nil {
 		t.Fatalf("Unable to open log: %v", err)
 	}
-	defer log.close()
+
 	defer os.Remove(path)
 
 	entry1, _ := newLogEntry(log, 1, 1, &testCommand1{Val: "foo", I: 20})
@@ -208,4 +208,29 @@ func TestLogTruncate(t *testing.T) {
 		t.Fatalf("Truncating at last commit should work: %v\n\nEntries:\nActual: %v\nExpected: %v", err, log.entries, []*LogEntry{entry1, entry2})
 	}
 
+	// Append after truncate
+	if err := log.appendEntry(entry3); err != nil {
+		t.Fatalf("Unable to append after truncate: %v", err)
+	}
+
+	log.close()
+
+	// Recovery the truncated log
+	log = newLog()
+	if err := log.open(path); err != nil {
+		t.Fatalf("Unable to open log: %v", err)
+	}
+	// Validate existing log entries.
+	if len(log.entries) != 3 {
+		t.Fatalf("Expected 3 entries, got %d", len(log.entries))
+	}
+	if log.entries[0].Index != 1 || log.entries[0].Term != 1 {
+		t.Fatalf("Unexpected entry[0]: %v", log.entries[0])
+	}
+	if log.entries[1].Index != 2 || log.entries[1].Term != 1 {
+		t.Fatalf("Unexpected entry[1]: %v", log.entries[1])
+	}
+	if log.entries[2].Index != 3 || log.entries[2].Term != 2 {
+		t.Fatalf("Unexpected entry[2]: %v", log.entries[2])
+	}
 }

protobuf/log_entry.pb.go

@@ -18,6 +18,7 @@ type ProtoLogEntry struct {
 	Term             *uint64 `protobuf:"varint,2,req" json:"Term,omitempty"`
 	CommandName      *string `protobuf:"bytes,3,req" json:"CommandName,omitempty"`
 	Command          []byte  `protobuf:"bytes,4,opt" json:"Command,omitempty"`
+	Position         *int64  `protobuf:"varint,5,req" json:"Position,omitempty"`
 	XXX_unrecognized []byte  `json:"-"`
 }
 
@@ -53,5 +54,12 @@ func (m *ProtoLogEntry) GetCommand() []byte {
 	return nil
 }
 
+func (m *ProtoLogEntry) GetPosition() int64 {
+	if m != nil && m.Position != nil {
+		return *m.Position
+	}
+	return 0
+}
+
 func init() {
 }

protobuf/log_entry.proto

@@ -5,4 +5,5 @@ message ProtoLogEntry {
 	required uint64 Term=2;
 	required string CommandName=3;
 	optional bytes Command=4; // for nop-command
+	required int64 Position=5;
 }

protobuf/snapshot_recovery_request.pb.go

@@ -1,5 +1,5 @@
 // Code generated by protoc-gen-go.
-// source: snapshot_recovery_resquest.proto
+// source: snapshot_recovery_request.proto
 // DO NOT EDIT!
 
 package protobuf