From aa38d9e8434355f880d25abb0b30c5ef789fc58b Mon Sep 17 00:00:00 2001
From: Danny Coates <dannycoates@gmail.com>
Date: Mon, 31 Dec 2012 13:54:25 -0800
Subject: [PATCH] refactored proposer a bit

---
 proposer/propose-state.js | 29 +++++++++++++++--------------
 proposer/proposer.js      | 19 ++++++++++---------
 2 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/proposer/propose-state.js b/proposer/propose-state.js
index b646403..56e9c6c 100644
--- a/proposer/propose-state.js
+++ b/proposer/propose-state.js
@@ -1,6 +1,6 @@
 module.exports = function (assert, inherits, EventEmitter, Prepare, Proposal) {
 
-	function Paxos(proposer, instance, ballot) {
+	function ProposeState(proposer, instance, ballot) {
 		EventEmitter.call(this)
 		this.proposerId = proposer.id
 		this.instance = instance
@@ -8,22 +8,26 @@ module.exports = function (assert, inherits, EventEmitter, Prepare, Proposal) {
 		this.value = null
 		this.valueBallot = 0
 
-		this.timer = null
+		// TODO: decide where timeouts go. At this point there's arguments for
+		// here, where they become part of the state, or in the communication
+		// layer which keeps the state "time free". I think I'd prefer to keep
+		// knowledge of time out of the state, but it seems easier to implement
+		// here. So lets try to do it "there" and only come back if its too ugly.
 
 		this.promises = []
 		this.majority = proposer.majority
 	}
-	inherits(Paxos, EventEmitter)
+	inherits(ProposeState, EventEmitter)
 
-	Paxos.create = function (proposer, instance, ballot) {
-		var state = new Paxos(proposer, instance, ballot)
+	ProposeState.create = function (proposer, instance, ballot) {
+		var state = new ProposeState(proposer, instance, ballot)
 		state.on('prepare', proposer.onPrepare)
 		state.on('accept', proposer.onAccept)
 		state.on('propose', proposer.onPropose)
 		return state
 	}
 
-	Paxos.prototype.nextBallot = function (previous) {
+	ProposeState.prototype.nextBallot = function (previous) {
 		var id = previous % 100
 		var counter = (previous - id) + 100 //here's the increment
 		this.ballot = counter + this.proposerId
@@ -31,14 +35,12 @@ module.exports = function (assert, inherits, EventEmitter, Prepare, Proposal) {
 		return this.ballot
 	}
 
-	Paxos.prototype.prepare = function (previousBallot) {
-		clearTimeout(this.timer)
+	ProposeState.prototype.prepare = function (previousBallot) {
 		this.nextBallot(previousBallot || this.ballot)
 		this.emit('prepare', new Prepare(this.instance, this.ballot))
 	}
 
-	Paxos.prototype.proposal = function () {
-		clearTimeout(this.timer)
+	ProposeState.prototype.proposal = function () {
 		var proposal = new Proposal(this.instance, this.ballot, this.value, this.valueBallot)
 		var event = this.value ? 'accept' : 'propose'
 		this.emit(event, proposal)
@@ -52,7 +54,7 @@ module.exports = function (assert, inherits, EventEmitter, Prepare, Proposal) {
 		return (a.valueBallot || 0) > (b.valueBallot || 0) ? a : b
 	}
 
-	Paxos.prototype.promised = function (proposal) {
+	ProposeState.prototype.promised = function (proposal) {
 		assert.equal(this.instance, proposal.instance)
 
 		if (this.ballot < proposal.ballot) {
@@ -74,12 +76,11 @@ module.exports = function (assert, inherits, EventEmitter, Prepare, Proposal) {
 		}
 	}
 
-	Paxos.prototype.complete = function (proposer) {
-		clearTimeout(this.timer)
+	ProposeState.prototype.complete = function (proposer) {
 		this.removeListener('prepare', proposer.onPrepare)
 		this.removeListener('accept', proposer.onAccept)
 		this.removeListener('propose', proposer.onPropose)
 	}
 
-	return Paxos
+	return ProposeState
 }
diff --git a/proposer/proposer.js b/proposer/proposer.js
index 1f37d0b..ea4f2e3 100644
--- a/proposer/proposer.js
+++ b/proposer/proposer.js
@@ -1,4 +1,4 @@
-module.exports = function (assert, inherits, EventEmitter, Paxos) {
+module.exports = function (assert, inherits, EventEmitter, ProposeState) {
 
 	function Proposer(id, majority, learner) {
 		assert(id < 100, "max id is 99")
@@ -15,18 +15,19 @@ module.exports = function (assert, inherits, EventEmitter, Paxos) {
 	}
 	inherits(Proposer, EventEmitter)
 
-	Proposer.prototype.prepare = function (instanceId) {
-		instanceId = instanceId || this.instanceCounter++
-		var instance = this.instances[instanceId] || Paxos.create(this, instanceId)
+	Proposer.prototype.instance = function (instanceId, ballot) {
+		var instance = this.instances[instanceId] ||
+			ProposeState.create(this, instanceId, ballot)
 		this.instances[instanceId] = instance
-		instance.prepare()
+		return instance
+	}
+
+	Proposer.prototype.prepare = function (instanceId) {
+		this.instance(instanceId || this.instanceCounter++).prepare()
 	}
 
 	Proposer.prototype.promised = function (proposal) {
-		var instance = this.instances[proposal.instance] ||
-			Paxos.create(this, proposal.instance, proposal.ballot)
-		this.instances[proposal.instance] = instance
-		instance.promised(proposal)
+		this.instance(proposal.instance, proposal.ballot).promised(proposal)
 	}
 
 	Proposer.prototype.accept = function (proposal) {