bump(github.com/benbjohnson/go-raft): d46748244f1f1830a002b8f645342426c5d73e81

third_party/github.com/benbjohnson/go-raft/log_entry.go

@@ -0,0 +1,99 @@
+package raft
+
+import (
+	"bytes"
+	"code.google.com/p/goprotobuf/proto"
+	"encoding/json"
+	"fmt"
+	"github.com/benbjohnson/go-raft/protobuf"
+	"io"
+)
+
+// A log entry stores a single item in the log.
+type LogEntry struct {
+	log         *Log
+	Index       uint64
+	Term        uint64
+	CommandName string
+	Command     []byte
+	Position    int64 // position in the log file
+	commit      chan bool
+}
+
+// Creates a new log entry associated with a log.
+func newLogEntry(log *Log, index uint64, term uint64, command Command) (*LogEntry, error) {
+	var buf bytes.Buffer
+	var commandName string
+	if command != nil {
+		commandName = command.CommandName()
+		if encoder, ok := command.(CommandEncoder); ok {
+			if err := encoder.Encode(&buf); err != nil {
+				return nil, err
+			}
+		} else {
+			json.NewEncoder(&buf).Encode(command)
+		}
+	}
+
+	e := &LogEntry{
+		log:         log,
+		Index:       index,
+		Term:        term,
+		CommandName: commandName,
+		Command:     buf.Bytes(),
+		commit:      make(chan bool, 5),
+	}
+
+	return e, nil
+}
+
+// Encodes the log entry to a buffer. Returns the number of bytes
+// written and any error that may have occurred.
+func (e *LogEntry) encode(w io.Writer) (int, error) {
+	defer e.log.pBuffer.Reset()
+	e.log.pLogEntry.Index = proto.Uint64(e.Index)
+	e.log.pLogEntry.Term = proto.Uint64(e.Term)
+	e.log.pLogEntry.CommandName = proto.String(e.CommandName)
+	e.log.pLogEntry.Command = e.Command
+
+	err := e.log.pBuffer.Marshal(e.log.pLogEntry)
+	if err != nil {
+		return -1, err
+	}
+
+	if _, err = fmt.Fprintf(w, "%8x\n", len(e.log.pBuffer.Bytes())); err != nil {
+		return -1, err
+	}
+
+	return w.Write(e.log.pBuffer.Bytes())
+}
+
+// Decodes the log entry from a buffer. Returns the number of bytes read and
+// any error that occurs.
+func (e *LogEntry) decode(r io.Reader) (int, error) {
+
+	var length int
+	_, err := fmt.Fscanf(r, "%8x\n", &length)
+	if err != nil {
+		return -1, err
+	}
+
+	data := make([]byte, length)
+	_, err = r.Read(data)
+
+	if err != nil {
+		return -1, err
+	}
+
+	pb := &protobuf.ProtoLogEntry{}
+	if err = proto.Unmarshal(data, pb); err != nil {
+		return -1, err
+	}
+
+	e.Term = pb.GetTerm()
+	e.Index = pb.GetIndex()
+	e.CommandName = pb.GetCommandName()
+	e.Command = pb.Command
+
+	return length, nil
+}