Adding some skeletons

config.go

@@ -0,0 +1,18 @@
+package raft
+
+import (
+	"time"
+)
+
+// Config provides any necessary configuraiton to
+// the Raft server
+type Config struct {
+	// Time without a leader before we attempt an election
+	ElectionTimeout time.Duration
+}
+
+func DefaultConfig() *Config {
+	return &Config{
+		ElectionTimeout: 150 * time.Millisecond,
+	}
+}

leader.go

@@ -0,0 +1,15 @@
+package raft
+
+// LeaderState is used to track the additional state
+// needed as a leader
+type LeaderState struct {
+	followers map[string]*FollowerState
+}
+
+type FollowerState struct {
+	// This is the next index to send
+	nextIndex uint64
+
+	// This is the last known replicated index
+	replicatedIndex uint64
+}

log.go

@@ -0,0 +1,25 @@
+package raft
+
+// Log entries are replicated to all members of the Raft cluster
+// and form the heart of the replicated state machine.
+type Log struct {
+	Index uint64
+	Term  uint64
+	Data  []byte
+}
+
+// LogStore is used to provide an interface for storing
+// and retrieving logs in a durable fashion
+type LogStore interface {
+	// Returns the last index written. 0 for no entries.
+	LastIndex() (uint64, error)
+
+	// Gets a log entry at a given index
+	GetLog(index uint64, log *Log) error
+
+	// Stores a log entry
+	StoreLog(log *Log) error
+
+	// Deletes a range of log entries. The range is inclusive.
+	DeleteRange(min, max uint64) error
+}

raft.go

@@ -0,0 +1,32 @@
+package raft
+
+type RaftState uint8
+
+const (
+	Follower RaftState = iota
+	Candidate
+	Leader
+)
+
+type Raft struct {
+	// Configuration
+	conf *Config
+
+	// Current state
+	state RaftState
+
+	// stable is a StableStore implementation for durable state
+	stable StableStore
+
+	// logs is a LogStore implementation to keep our logs
+	logs LogStore
+
+	// Highest commited log entry
+	commitIndex uint64
+
+	// Last applied log to the FSM
+	lastApplied uint64
+
+	// If we are the leader, we have extra state
+	leader *LeaderState
+}

stable.go

@@ -0,0 +1,21 @@
+package raft
+
+// StableStore is used to provide stable storage
+// of key configurations to ensure safety.
+type StableStore interface {
+	// Returns the current term
+	CurrentTerm() (uint64, error)
+
+	// Returns the candidate we voted for this term
+	VotedFor() (string, error)
+
+	// Sets the current term. Clears the current vote.
+	SetCurrentTerm(uint64) error
+
+	// Sets a candidate vote for the current term
+	SetVote(string) error
+
+	// Returns our candidate ID. This should be unique
+	// and constant across runs
+	CandidateID() (string, error)
+}