From 2d6a9bbb1828ff5d050a8a487fc1d87e5789209d Mon Sep 17 00:00:00 2001
From: Derek Leung <derek@algorand.com>
Date: Wed, 18 Dec 2019 17:41:18 -0500
Subject: [PATCH] Support variable-delay protocol upgrades in ConsensusFuture.

Also add some unit tests for variable-delay protocol upgrades.
---
 config/config.go               |  2 ++
 data/bookkeeping/block_test.go | 57 ++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/config/config.go b/config/config.go
index d20f8d8f80..0047d54dfb 100644
--- a/config/config.go
+++ b/config/config.go
@@ -480,6 +480,8 @@ func initConsensusProtocols() {
 	// but not yet released in a production protocol version.
 	vFuture := v20
 	vFuture.ApprovedUpgrades = map[protocol.ConsensusVersion]uint64{}
+	vFuture.MinUpgradeWaitRounds = 10000
+	vFuture.MaxUpgradeWaitRounds = 150000
 	Consensus[protocol.ConsensusFuture] = vFuture
 }
 
diff --git a/data/bookkeeping/block_test.go b/data/bookkeeping/block_test.go
index 6fe6ed839b..c3e68a6112 100644
--- a/data/bookkeeping/block_test.go
+++ b/data/bookkeeping/block_test.go
@@ -35,6 +35,7 @@ var proto1 = protocol.ConsensusVersion("Test1")
 var proto2 = protocol.ConsensusVersion("Test2")
 var proto3 = protocol.ConsensusVersion("Test3")
 var protoUnsupported = protocol.ConsensusVersion("TestUnsupported")
+var protoDelay = protocol.ConsensusVersion("TestDelay")
 
 func init() {
 	params1 := config.Consensus[protocol.ConsensusCurrentVersion]
@@ -46,6 +47,14 @@ func init() {
 	params2 := config.Consensus[protocol.ConsensusCurrentVersion]
 	params2.ApprovedUpgrades = map[protocol.ConsensusVersion]uint64{}
 	config.Consensus[proto2] = params2
+
+	paramsDelay := config.Consensus[protocol.ConsensusCurrentVersion]
+	paramsDelay.MinUpgradeWaitRounds = 3
+	paramsDelay.MaxUpgradeWaitRounds = 7
+	paramsDelay.ApprovedUpgrades = map[protocol.ConsensusVersion]uint64{
+		proto1: 5,
+	}
+	config.Consensus[protoDelay] = paramsDelay
 }
 
 func TestUpgradeVote(t *testing.T) {
@@ -109,6 +118,30 @@ func TestUpgradeVote(t *testing.T) {
 	require.Equal(t, s1.NextProtocolSwitchOn, basics.Round(0))
 }
 
+func TestUpgradeVariableDelay(t *testing.T) {
+	s := UpgradeState{
+		CurrentProtocol: protoDelay,
+	}
+
+	_, err := s.applyUpgradeVote(basics.Round(10), UpgradeVote{UpgradePropose: proto1, UpgradeDelay: 2})
+	require.Error(t, err, "accepted upgrade vote with delay less than MinUpgradeWaitRounds")
+
+	_, err = s.applyUpgradeVote(basics.Round(10), UpgradeVote{UpgradePropose: proto1, UpgradeDelay: 8})
+	require.Error(t, err, "accepted upgrade vote with delay more than MaxUpgradeWaitRounds")
+
+	_, err = s.applyUpgradeVote(basics.Round(10), UpgradeVote{UpgradePropose: proto1, UpgradeDelay: 5})
+	require.NoError(t, err, "did not accept upgrade vote with in-bounds delay")
+
+	_, err = s.applyUpgradeVote(basics.Round(10), UpgradeVote{UpgradePropose: proto1, UpgradeDelay: 3})
+	require.NoError(t, err, "did not accept upgrade vote with minimal delay")
+
+	_, err = s.applyUpgradeVote(basics.Round(10), UpgradeVote{UpgradePropose: proto1, UpgradeDelay: 7})
+	require.NoError(t, err, "did not accept upgrade vote with maximal delay")
+
+	_, err = s.applyUpgradeVote(basics.Round(10), UpgradeVote{UpgradePropose: proto1, UpgradeDelay: 0})
+	require.Error(t, err, "accepted upgrade vote with zero (below minimal) delay")
+}
+
 func TestMakeBlockUpgrades(t *testing.T) {
 	var b Block
 	b.BlockHeader.GenesisID = t.Name()
@@ -133,6 +166,30 @@ func TestMakeBlockUpgrades(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, b3.UpgradePropose, protocol.ConsensusVersion(""))
 	require.Equal(t, b3.UpgradeApprove, false)
+
+	var bd Block
+	bd.BlockHeader.GenesisID = t.Name()
+	bd.CurrentProtocol = protoDelay
+	bd.BlockHeader.GenesisID = "test"
+	crypto.RandBytes(bd.BlockHeader.GenesisHash[:])
+
+	bd1 := MakeBlock(bd.BlockHeader)
+	err = bd1.PreCheck(bd.BlockHeader)
+	require.NoError(t, err)
+	require.Equal(t, bd1.UpgradePropose, proto1)
+	require.Equal(t, bd1.UpgradeApprove, true)
+	require.Equal(t, bd1.UpgradeDelay, basics.Round(5))
+	require.Equal(t, bd1.NextProtocol, proto1)
+	require.Equal(t, bd1.NextProtocolSwitchOn-bd1.NextProtocolVoteBefore, basics.Round(5))
+
+	bd2 := MakeBlock(bd1.BlockHeader)
+	err = bd2.PreCheck(bd1.BlockHeader)
+	require.NoError(t, err)
+	require.Equal(t, bd2.UpgradePropose, protocol.ConsensusVersion(""))
+	require.Equal(t, bd2.UpgradeApprove, true)
+	require.Equal(t, bd2.UpgradeDelay, basics.Round(0))
+	require.Equal(t, bd2.NextProtocol, proto1)
+	require.Equal(t, bd2.NextProtocolSwitchOn-bd2.NextProtocolVoteBefore, basics.Round(5))
 }
 
 func TestBlockUnsupported(t *testing.T) {