core: core.Lattice supports config change (#276)

Besides making core.Lattice supports config change,
This PR also include the first test for below scenario:
- Configuration changes are registered before test
   running
- Those changes are carried/broadcasted as payload
   of blocks
- Only one node would initiate these changes, however,
   all nodes would finally receive/apply those changes
   to their own test.Governance instance.

3 files changed, 50 insertions, 24 deletions

diff --git a/core/test/app.go b/core/test/app.go
index 546c9e5..4976ae0 100644
--- a/core/test/app.go
+++ b/core/test/app.go
@@ -88,22 +88,30 @@ type App struct {
 	Delivered          map[common.Hash]*AppDeliveredRecord
 	DeliverSequence    common.Hashes
 	deliveredLock      sync.RWMutex
+	blocks             map[common.Hash]*types.Block
+	blocksLock         sync.Mutex
+	state              *State
 }
 
 // NewApp constructs a TestApp instance.
-func NewApp() *App {
+func NewApp(state *State) *App {
 	return &App{
 		Acked:              make(map[common.Hash]*AppAckedRecord),
 		TotalOrdered:       []*AppTotalOrderRecord{},
 		TotalOrderedByHash: make(map[common.Hash]*AppTotalOrderRecord),
 		Delivered:          make(map[common.Hash]*AppDeliveredRecord),
 		DeliverSequence:    common.Hashes{},
+		blocks:             make(map[common.Hash]*types.Block),
+		state:              state,
 	}
 }
 
 // PreparePayload implements Application interface.
 func (app *App) PreparePayload(position types.Position) ([]byte, error) {
-	return []byte{}, nil
+	if app.state == nil {
+		return []byte{}, nil
+	}
+	return app.state.PackRequests()
 }
 
 // PrepareWitness implements Application interface.
@@ -119,7 +127,10 @@ func (app *App) VerifyBlock(block *types.Block) types.BlockVerifyStatus {
 }
 
 // BlockConfirmed implements Application interface.
-func (app *App) BlockConfirmed(_ types.Block) {
+func (app *App) BlockConfirmed(b types.Block) {
+	app.blocksLock.Lock()
+	defer app.blocksLock.Unlock()
+	app.blocks[b.Hash] = &b
 }
 
 // StronglyAcked implements Application interface.
@@ -152,15 +163,30 @@ func (app *App) TotalOrderingDelivered(blockHashes common.Hashes, mode uint32) {
 // BlockDelivered implements Application interface.
 func (app *App) BlockDelivered(
 	blockHash common.Hash, result types.FinalizationResult) {
-	app.deliveredLock.Lock()
-	defer app.deliveredLock.Unlock()
-
-	app.Delivered[blockHash] = &AppDeliveredRecord{
-		ConsensusTime:   result.Timestamp,
-		ConsensusHeight: result.Height,
-		When:            time.Now().UTC(),
-	}
-	app.DeliverSequence = append(app.DeliverSequence, blockHash)
+	func() {
+		app.deliveredLock.Lock()
+		defer app.deliveredLock.Unlock()
+		app.Delivered[blockHash] = &AppDeliveredRecord{
+			ConsensusTime:   result.Timestamp,
+			ConsensusHeight: result.Height,
+			When:            time.Now().UTC(),
+		}
+		app.DeliverSequence = append(app.DeliverSequence, blockHash)
+	}()
+	// Apply packed state change requests in payload.
+	func() {
+		if app.state == nil {
+			return
+		}
+		app.blocksLock.Lock()
+		defer app.blocksLock.Unlock()
+		b := app.blocks[blockHash]
+		if err := app.state.Apply(b.Payload); err != nil {
+			if err != ErrDuplicatedChange {
+				panic(err)
+			}
+		}
+	}()
 }
 
 // Compare performs these checks against another App instance
diff --git a/core/test/app_test.go b/core/test/app_test.go
index 823bde0..933343f 100644
--- a/core/test/app_test.go
+++ b/core/test/app_test.go
@@ -91,12 +91,12 @@ func (s *AppTestSuite) deliverBlock(
 func (s *AppTestSuite) TestCompare() {
 	req := s.Require()
 
-	app1 := NewApp()
+	app1 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app1, s.to1)
 	s.setupAppByTotalOrderDeliver(app1, s.to2)
 	s.setupAppByTotalOrderDeliver(app1, s.to3)
 	// An App with different deliver sequence.
-	app2 := NewApp()
+	app2 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app2, s.to1)
 	s.setupAppByTotalOrderDeliver(app2, s.to2)
 	hash := common.NewRandomHash()
@@ -105,7 +105,7 @@ func (s *AppTestSuite) TestCompare() {
 	s.deliverBlockWithTimeFromSequenceLength(app2, hash)
 	req.Equal(ErrMismatchBlockHashSequence, app1.Compare(app2))
 	// An App with different consensus time for the same block.
-	app3 := NewApp()
+	app3 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app3, s.to1)
 	s.setupAppByTotalOrderDeliver(app3, s.to2)
 	for _, h := range s.to3.BlockHashes {
@@ -120,7 +120,7 @@ func (s *AppTestSuite) TestCompare() {
 	req.Equal(ErrMismatchConsensusTime, app1.Compare(app3))
 	req.Equal(ErrMismatchConsensusTime, app3.Compare(app1))
 	// An App without any delivered blocks.
-	app4 := NewApp()
+	app4 := NewApp(nil)
 	req.Equal(ErrEmptyDeliverSequence, app4.Compare(app1))
 	req.Equal(ErrEmptyDeliverSequence, app1.Compare(app4))
 }
@@ -129,7 +129,7 @@ func (s *AppTestSuite) TestVerify() {
 	req := s.Require()
 
 	// An OK App instance.
-	app1 := NewApp()
+	app1 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app1, s.to1)
 	s.setupAppByTotalOrderDeliver(app1, s.to2)
 	s.setupAppByTotalOrderDeliver(app1, s.to3)
@@ -139,7 +139,7 @@ func (s *AppTestSuite) TestVerify() {
 		uint64(len(app1.DeliverSequence)))
 	req.Equal(ErrDeliveredBlockNotAcked, app1.Verify())
 	// The consensus time is out of order.
-	app2 := NewApp()
+	app2 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app2, s.to1)
 	for _, h := range s.to2.BlockHashes {
 		app2.StronglyAcked(h)
@@ -149,14 +149,14 @@ func (s *AppTestSuite) TestVerify() {
 		uint64(len(app2.DeliverSequence)+1))
 	req.Equal(ErrConsensusTimestampOutOfOrder, app2.Verify())
 	// A delivered block is not found in total ordering delivers.
-	app3 := NewApp()
+	app3 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app3, s.to1)
 	hash := common.NewRandomHash()
 	app3.StronglyAcked(hash)
 	s.deliverBlockWithTimeFromSequenceLength(app3, hash)
 	req.Equal(ErrMismatchTotalOrderingAndDelivered, app3.Verify())
 	// A delivered block is not found in total ordering delivers.
-	app4 := NewApp()
+	app4 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app4, s.to1)
 	for _, h := range s.to2.BlockHashes {
 		app4.StronglyAcked(h)
@@ -167,10 +167,10 @@ func (s *AppTestSuite) TestVerify() {
 	app4.TotalOrderingDelivered(common.Hashes{hash}, core.TotalOrderingModeNormal)
 	s.deliverBlockWithTimeFromSequenceLength(app4, hash)
 	// Witness ack on unknown block.
-	app5 := NewApp()
+	app5 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app5, s.to1)
 	// The conensus height is out of order.
-	app6 := NewApp()
+	app6 := NewApp(nil)
 	s.setupAppByTotalOrderDeliver(app6, s.to1)
 	for _, h := range s.to2.BlockHashes {
 		app6.StronglyAcked(h)
diff --git a/core/test/stopper_test.go b/core/test/stopper_test.go
index 23c0137..f54c2d1 100644
--- a/core/test/stopper_test.go
+++ b/core/test/stopper_test.go
@@ -70,7 +70,7 @@ func (s *StopperTestSuite) TestStopByConfirmedBlocks() {
 		nodes = GenerateRandomNodeIDs(2)
 	)
 	for _, nID := range nodes {
-		apps[nID] = NewApp()
+		apps[nID] = NewApp(nil)
 		db, err := blockdb.NewMemBackedBlockDB()
 		req.NoError(err)
 		dbs[nID] = db
@@ -118,7 +118,7 @@ func (s *StopperTestSuite) TestStopByRound() {
 		nodes = GenerateRandomNodeIDs(2)
 	)
 	for _, nID := range nodes {
-		apps[nID] = NewApp()
+		apps[nID] = NewApp(nil)
 		db, err := blockdb.NewMemBackedBlockDB()
 		req.NoError(err)
 		dbs[nID] = db