move MLPR frmo log to server

log.go

@@ -9,10 +9,6 @@ import (
 	"sync"
 )
 
-const (
-	MaxLogEntriesPerRequest = 200
-)
-
 //------------------------------------------------------------------------------
 //
 // Typedefs
@@ -21,16 +17,15 @@ const (
 
 // A log is a collection of log entries that are persisted to durable storage.
 type Log struct {
-	ApplyFunc               func(Command) (interface{}, error)
-	file                    *os.File
-	path                    string
-	entries                 []*LogEntry
-	results                 []*logResult
-	commitIndex             uint64
-	mutex                   sync.RWMutex
-	startIndex              uint64 // the index before the first entry in the Log entries
-	startTerm               uint64
-	maxLogEntriesPerRequest uint64
+	ApplyFunc   func(Command) (interface{}, error)
+	file        *os.File
+	path        string
+	entries     []*LogEntry
+	results     []*logResult
+	commitIndex uint64
+	mutex       sync.RWMutex
+	startIndex  uint64 // the index before the first entry in the Log entries
+	startTerm   uint64
 }
 
 // The results of the applying a log entry.
@@ -48,8 +43,7 @@ type logResult struct {
 // Creates a new log.
 func newLog() *Log {
 	return &Log{
-		entries:                 make([]*LogEntry, 0),
-		maxLogEntriesPerRequest: MaxLogEntriesPerRequest,
+		entries: make([]*LogEntry, 0),
 	}
 }
 
@@ -239,7 +233,7 @@ func (l *Log) containsEntry(index uint64, term uint64) bool {
 // Retrieves a list of entries after a given index as well as the term of the
 // index provided. A nil list of entries is returned if the index no longer
 // exists because a snapshot was made.
-func (l *Log) getEntriesAfter(index uint64) ([]*LogEntry, uint64) {
+func (l *Log) getEntriesAfter(index uint64, maxLogEntriesPerRequest uint64) ([]*LogEntry, uint64) {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
 
@@ -265,11 +259,11 @@ func (l *Log) getEntriesAfter(index uint64) ([]*LogEntry, uint64) {
 	entries := l.entries[index-l.startIndex:]
 	length := len(entries)
 
-	if uint64(length) < l.maxLogEntriesPerRequest {
+	if uint64(length) < maxLogEntriesPerRequest {
 		// Determine the term at the given entry and return a subslice.
 		return entries, l.entries[index-1-l.startIndex].Term
 	} else {
-		return entries[:l.maxLogEntriesPerRequest], l.entries[index-1-l.startIndex].Term
+		return entries[:maxLogEntriesPerRequest], l.entries[index-1-l.startIndex].Term
 	}
 }
 

peer.go

@@ -139,7 +139,7 @@ func (p *Peer) heartbeat(c chan bool) {
 		case <-time.After(p.heartbeatTimeout):
 			debugln("peer.heartbeat.run: ", p.Name())
 			prevLogIndex := p.getPrevLogIndex()
-			entries, prevLogTerm := p.server.log.getEntriesAfter(prevLogIndex)
+			entries, prevLogTerm := p.server.log.getEntriesAfter(prevLogIndex, p.server.maxLogEntriesPerRequest)
 
 			if p.server.State() != Leader {
 				return

server.go

@@ -26,6 +26,10 @@ const (
 	Leader    = "leader"
 )
 
+const (
+	MaxLogEntriesPerRequest = 200
+)
+
 const (
 	DefaultHeartbeatTimeout = 50 * time.Millisecond
 	DefaultElectionTimeout  = 150 * time.Millisecond
@@ -70,9 +74,10 @@ type Server struct {
 	electionTimeout  time.Duration
 	heartbeatTimeout time.Duration
 
-	currentSnapshot *Snapshot
-	lastSnapshot    *Snapshot
-	stateMachine    StateMachine
+	currentSnapshot         *Snapshot
+	lastSnapshot            *Snapshot
+	stateMachine            StateMachine
+	maxLogEntriesPerRequest uint64
 }
 
 // An event to be processed by the server's event loop.
@@ -98,17 +103,18 @@ func NewServer(name string, path string, transporter Transporter, stateMachine S
 	}
 
 	s := &Server{
-		name:             name,
-		path:             path,
-		transporter:      transporter,
-		stateMachine:     stateMachine,
-		context:          context,
-		state:            Stopped,
-		peers:            make(map[string]*Peer),
-		log:              newLog(),
-		c:                make(chan *event, 256),
-		electionTimeout:  DefaultElectionTimeout,
-		heartbeatTimeout: DefaultHeartbeatTimeout,
+		name:                    name,
+		path:                    path,
+		transporter:             transporter,
+		stateMachine:            stateMachine,
+		context:                 context,
+		state:                   Stopped,
+		peers:                   make(map[string]*Peer),
+		log:                     newLog(),
+		c:                       make(chan *event, 256),
+		electionTimeout:         DefaultElectionTimeout,
+		heartbeatTimeout:        DefaultHeartbeatTimeout,
+		maxLogEntriesPerRequest: MaxLogEntriesPerRequest,
 	}
 
 	// Setup apply function.