core: No randomness for round 0 (#198)

* No randomness for round 0
* Ignore round 0 randomness

3 files changed, 45 insertions, 1 deletions

diff --git a/core/compaction-chain.go b/core/compaction-chain.go
index c176f65..6803661 100644
--- a/core/compaction-chain.go
+++ b/core/compaction-chain.go
@@ -80,7 +80,8 @@ func (cc *compactionChain) extractBlocks() []*types.Block {
 	cc.blocksLock.Lock()
 	defer cc.blocksLock.Unlock()
 	for len(cc.pendingBlocks) != 0 &&
-		len(cc.pendingBlocks[0].Finalization.Randomness) != 0 {
+		(len(cc.pendingBlocks[0].Finalization.Randomness) != 0 ||
+			cc.pendingBlocks[0].Position.Round == 0) {
 		var block *types.Block
 		block, cc.pendingBlocks = cc.pendingBlocks[0], cc.pendingBlocks[1:]
 		delete(cc.blocks, block.Hash)
diff --git a/core/compaction-chain_test.go b/core/compaction-chain_test.go
index 3366d5f..f91f1a1 100644
--- a/core/compaction-chain_test.go
+++ b/core/compaction-chain_test.go
@@ -84,6 +84,9 @@ func (s *CompactionChainTestSuite) TestExtractBlocks() {
 	for idx := range blocks {
 		blocks[idx] = &types.Block{
 			Hash: common.NewRandomHash(),
+			Position: types.Position{
+				Round: 1,
+			},
 		}
 		s.Require().False(cc.blockRegistered(blocks[idx].Hash))
 		cc.registerBlock(blocks[idx])
@@ -155,6 +158,40 @@ func (s *CompactionChainTestSuite) TestExtractBlocks() {
 	}
 }
 
+func (s *CompactionChainTestSuite) TestExtractBlocksRound0() {
+	cc := s.newCompactionChain()
+	blocks := make([]*types.Block, 10)
+	for idx := range blocks {
+		blocks[idx] = &types.Block{
+			Hash: common.NewRandomHash(),
+			Position: types.Position{
+				Round: 0,
+			},
+		}
+		s.Require().False(cc.blockRegistered(blocks[idx].Hash))
+		cc.registerBlock(blocks[idx])
+		s.Require().True(cc.blockRegistered(blocks[idx].Hash))
+	}
+	// Round 0 should be able to be extracted without randomness.
+	for i := 0; i < 3; i++ {
+		s.Require().NoError(cc.processBlock(blocks[i]))
+	}
+	delivered := cc.extractBlocks()
+	s.Require().Len(delivered, 3)
+
+	// Round 0 should be able to be extracted without randomness.
+	for i := 3; i < 10; i++ {
+		s.Require().NoError(cc.processBlock(blocks[i]))
+	}
+	delivered = append(delivered, cc.extractBlocks()...)
+	s.Require().Len(delivered, 10)
+
+	// The delivered order should be the same as processing order.
+	for i, block := range delivered {
+		s.Equal(block.Hash, blocks[i].Hash)
+	}
+}
+
 func TestCompactionChain(t *testing.T) {
 	suite.Run(t, new(CompactionChainTestSuite))
 }
diff --git a/core/consensus.go b/core/consensus.go
index 90a8f09..b5cb445 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -553,6 +553,9 @@ func (con *Consensus) ProcessVote(vote *types.Vote) (err error) {
 // ProcessAgreementResult processes the randomness request.
 func (con *Consensus) ProcessAgreementResult(
 	rand *types.AgreementResult) error {
+	if rand.Round == 0 {
+		return nil
+	}
 	if !con.ccModule.blockRegistered(rand.BlockHash) {
 		return nil
 	}
@@ -625,6 +628,9 @@ func (con *Consensus) ProcessAgreementResult(
 // ProcessBlockRandomnessResult processes the randomness result.
 func (con *Consensus) ProcessBlockRandomnessResult(
 	rand *types.BlockRandomnessResult) error {
+	if rand.Round == 0 {
+		return nil
+	}
 	if !con.ccModule.blockRegistered(rand.BlockHash) {
 		return nil
 	}