core: fix stuffs (#250)

* fix discontinuous finalization height
* remove types.Block.Witness.Timestamp field
* add field: types.Block.Finalization.ParentHash
* fix log format of CRS
* switch round and chain in log of types.Position.

9 files changed, 33 insertions, 52 deletions

diff --git a/core/compaction-chain.go b/core/compaction-chain.go
index 5b13f7f..451cb13 100644
--- a/core/compaction-chain.go
+++ b/core/compaction-chain.go
@@ -132,6 +132,7 @@ func (cc *compactionChain) extractBlocks() []*types.Block {
 		cc.pendingBlocks = cc.pendingBlocks[1:]
 
 		block := cc.pendingBlocks[0]
+		block.Finalization.ParentHash = prevBlock.Hash
 		block.Finalization.Height = prevBlock.Finalization.Height + 1
 		deliveringBlocks = append(deliveringBlocks, block)
 		prevBlock = block
@@ -204,8 +205,7 @@ func (cc *compactionChain) extractFinalizedBlocks() []*types.Block {
 			continue
 		}
 		// Fork resolution: choose block with smaller hash.
-		if prevBlock.Finalization.Height ==
-			b.Finalization.Height {
+		if prevBlock.Finalization.Height == b.Finalization.Height {
 			//TODO(jimmy-dexon): remove this panic after test.
 			if true {
 				// workaround to `go vet` error
diff --git a/core/compaction-chain_test.go b/core/compaction-chain_test.go
index f4860fb..3e588b3 100644
--- a/core/compaction-chain_test.go
+++ b/core/compaction-chain_test.go
@@ -166,6 +166,8 @@ func (s *CompactionChainTestSuite) TestExtractBlocks() {
 		if i > 1 {
 			s.Equal(delivered[i-1].Finalization.Height+1,
 				delivered[i].Finalization.Height)
+			s.Equal(delivered[i-1].Hash,
+				delivered[i].Finalization.ParentHash)
 		}
 		s.Equal(block.Hash, blocks[i].Hash)
 	}
@@ -243,6 +245,9 @@ func (s *CompactionChainTestSuite) TestSyncFinalizedBlock() {
 			},
 		}
 		now = now.Add(100 * time.Millisecond)
+		if idx > 0 {
+			blocks[idx].Finalization.ParentHash = blocks[idx-1].Hash
+		}
 	}
 	cc.processFinalizedBlock(blocks[1])
 	cc.processFinalizedBlock(blocks[3])
@@ -330,6 +335,9 @@ func (s *CompactionChainTestSuite) TestSync() {
 			},
 		}
 		now = now.Add(100 * time.Millisecond)
+		if idx > 0 {
+			blocks[idx].Finalization.ParentHash = blocks[idx-1].Hash
+		}
 		if idx > 10 {
 			blocks[idx].Finalization.Height = 0
 		}
@@ -353,6 +361,7 @@ func (s *CompactionChainTestSuite) TestSync() {
 	confirmed := cc.extractBlocks()
 	s.Require().Len(confirmed, 1)
 	s.Equal(confirmed[0].Hash, blocks[12].Hash)
+	s.Equal(blocks[11].Hash, blocks[12].Finalization.ParentHash)
 	s.Equal(uint64(13), blocks[12].Finalization.Height)
 	for i := 13; i < 20; i++ {
 		s.Require().NoError(cc.processBlock(blocks[i]))
@@ -362,6 +371,7 @@ func (s *CompactionChainTestSuite) TestSync() {
 	offset := 13
 	for i, b := range confirmed {
 		s.Equal(blocks[offset+i].Hash, b.Hash)
+		s.Equal(blocks[offset+i-1].Hash, b.Finalization.ParentHash)
 		s.Equal(uint64(offset+i+1), b.Finalization.Height)
 	}
 }
@@ -388,6 +398,9 @@ func (s *CompactionChainTestSuite) TestBootstrapSync() {
 			},
 		}
 		now = now.Add(100 * time.Millisecond)
+		if idx > 0 {
+			blocks[idx].Finalization.ParentHash = blocks[idx-1].Hash
+		}
 		if idx > 2 {
 			blocks[idx].Finalization.Height = 0
 		}
@@ -411,6 +424,7 @@ func (s *CompactionChainTestSuite) TestBootstrapSync() {
 	confirmed = cc.extractBlocks()
 	s.Require().Len(confirmed, 1)
 	s.Equal(confirmed[0].Hash, blocks[3].Hash)
+	s.Equal(blocks[2].Hash, blocks[3].Finalization.ParentHash)
 	s.Equal(uint64(4), blocks[3].Finalization.Height)
 }
 
diff --git a/core/consensus.go b/core/consensus.go
index 0385558..a311851 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -545,7 +545,7 @@ func (con *Consensus) runCRS() {
 		} else {
 			con.logger.Debug("Calling Governance.ProposeCRS",
 				"round", con.round+1,
-				"crs", crs)
+				"crs", hex.EncodeToString(crs))
 			con.gov.ProposeCRS(con.round+1, crs)
 		}
 	}
@@ -846,7 +846,7 @@ func (con *Consensus) processBlock(block *types.Block) (err error) {
 	deliveredBlocks = con.ccModule.extractBlocks()
 	for _, b := range deliveredBlocks {
 		if err = con.db.Put(*b); err != nil {
-			return
+			panic(err)
 		}
 		// TODO(mission): clone types.FinalizationResult
 		con.app.BlockDelivered(b.Hash, b.Finalization)
diff --git a/core/crypto.go b/core/crypto.go
index f3870a5..f792c09 100644
--- a/core/crypto.go
+++ b/core/crypto.go
@@ -26,15 +26,10 @@ import (
 )
 
 func hashWitness(witness *types.Witness) (common.Hash, error) {
-	binaryTimestamp, err := witness.Timestamp.UTC().MarshalBinary()
-	if err != nil {
-		return common.Hash{}, err
-	}
 	binaryHeight := make([]byte, 8)
 	binary.LittleEndian.PutUint64(binaryHeight, witness.Height)
 	return crypto.Keccak256Hash(
 		binaryHeight,
-		binaryTimestamp,
 		witness.Data), nil
 }
 
diff --git a/core/nonblocking_test.go b/core/nonblocking_test.go
index 2ab40ea..637ec43 100644
--- a/core/nonblocking_test.go
+++ b/core/nonblocking_test.go
@@ -135,7 +135,7 @@ func (s *NonBlockingTestSuite) TestNonBlocking() {
 	for _, hash := range hashes {
 		nbModule.BlockConfirmed(types.Block{
 			Hash:    hash,
-			Witness: types.Witness{Timestamp: time.Now().UTC()},
+			Witness: types.Witness{},
 		})
 		nbModule.StronglyAcked(hash)
 		nbModule.BlockDelivered(hash, types.FinalizationResult{})
diff --git a/core/types/block.go b/core/types/block.go
index 29b1c84..e12e0d5 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -77,12 +77,14 @@ func (t *rlpTimestamp) DecodeRLP(s *rlp.Stream) error {
 
 // FinalizationResult represents the result of DEXON consensus algorithm.
 type FinalizationResult struct {
-	Randomness []byte    `json:"randomness"`
-	Timestamp  time.Time `json:"timestamp"`
-	Height     uint64    `json:"height"`
+	ParentHash common.Hash `json:"parent_hash"`
+	Randomness []byte      `json:"randomness"`
+	Timestamp  time.Time   `json:"timestamp"`
+	Height     uint64      `json:"height"`
 }
 
 type rlpFinalizationResult struct {
+	ParentHash common.Hash
 	Randomness []byte
 	Timestamp  *rlpTimestamp
 	Height     uint64
@@ -91,6 +93,7 @@ type rlpFinalizationResult struct {
 // EncodeRLP implements rlp.Encoder
 func (f *FinalizationResult) EncodeRLP(w io.Writer) error {
 	return rlp.Encode(w, &rlpFinalizationResult{
+		ParentHash: f.ParentHash,
 		Randomness: f.Randomness,
 		Timestamp:  &rlpTimestamp{f.Timestamp},
 		Height:     f.Height,
@@ -103,6 +106,7 @@ func (f *FinalizationResult) DecodeRLP(s *rlp.Stream) error {
 	err := s.Decode(&dec)
 	if err == nil {
 		*f = FinalizationResult{
+			ParentHash: dec.ParentHash,
 			Randomness: dec.Randomness,
 			Timestamp:  dec.Timestamp.Time,
 			Height:     dec.Height,
@@ -113,38 +117,8 @@ func (f *FinalizationResult) DecodeRLP(s *rlp.Stream) error {
 
 // Witness represents the consensus information on the compaction chain.
 type Witness struct {
-	Timestamp time.Time `json:"timestamp"`
-	Height    uint64    `json:"height"`
-	Data      []byte    `json:"data"`
-}
-
-type rlpWitness struct {
-	Timestamp *rlpTimestamp
-	Height    uint64
-	Data      []byte
-}
-
-// EncodeRLP implements rlp.Encoder
-func (w *Witness) EncodeRLP(writer io.Writer) error {
-	return rlp.Encode(writer, rlpWitness{
-		Timestamp: &rlpTimestamp{w.Timestamp},
-		Height:    w.Height,
-		Data:      w.Data,
-	})
-}
-
-// DecodeRLP implements rlp.Decoder
-func (w *Witness) DecodeRLP(s *rlp.Stream) error {
-	var dec rlpWitness
-	err := s.Decode(&dec)
-	if err == nil {
-		*w = Witness{
-			Timestamp: dec.Timestamp.Time,
-			Height:    dec.Height,
-			Data:      dec.Data,
-		}
-	}
-	return err
+	Height uint64 `json:"height"`
+	Data   []byte `json:"data"`
 }
 
 // RecycleBlock put unused block into cache, which might be reused if
@@ -245,9 +219,9 @@ func (b *Block) Clone() (bcopy *Block) {
 	bcopy.Position.Height = b.Position.Height
 	bcopy.Signature = b.Signature.Clone()
 	bcopy.CRSSignature = b.CRSSignature.Clone()
+	bcopy.Finalization.ParentHash = b.Finalization.ParentHash
 	bcopy.Finalization.Timestamp = b.Finalization.Timestamp
 	bcopy.Finalization.Height = b.Finalization.Height
-	bcopy.Witness.Timestamp = b.Witness.Timestamp
 	bcopy.Witness.Height = b.Witness.Height
 	bcopy.Witness.Data = make([]byte, len(b.Witness.Data))
 	copy(bcopy.Witness.Data, b.Witness.Data)
diff --git a/core/types/block_test.go b/core/types/block_test.go
index 758619d..7bf6a75 100644
--- a/core/types/block_test.go
+++ b/core/types/block_test.go
@@ -55,9 +55,8 @@ func (s *BlockTestSuite) createRandomBlock() *Block {
 		}),
 		Timestamp: time.Now().UTC(),
 		Witness: Witness{
-			Height:    rand.Uint64(),
-			Timestamp: time.Now().UTC(),
-			Data:      s.randomBytes(),
+			Height: rand.Uint64(),
+			Data:   s.randomBytes(),
 		},
 		Finalization: FinalizationResult{
 			Timestamp:  time.Now().UTC(),
diff --git a/core/types/position.go b/core/types/position.go
index 51de405..f41be32 100644
--- a/core/types/position.go
+++ b/core/types/position.go
@@ -35,7 +35,7 @@ type Position struct {
 }
 
 func (pos *Position) String() string {
-	return fmt.Sprintf("pos[%d:%d:%d]", pos.ChainID, pos.Round, pos.Height)
+	return fmt.Sprintf("pos[%d:%d:%d]", pos.Round, pos.ChainID, pos.Height)
 }
 
 // Equal checks if two positions are equal, it panics when their chainIDs
diff --git a/simulation/app.go b/simulation/app.go
index 419bb0a..f074dec 100644
--- a/simulation/app.go
+++ b/simulation/app.go
@@ -147,8 +147,7 @@ func (a *simApp) BlockDelivered(
 		a.latestWitnessReady.L.Lock()
 		defer a.latestWitnessReady.L.Unlock()
 		a.latestWitness = types.Witness{
-			Timestamp: result.Timestamp,
-			Height:    result.Height,
+			Height: result.Height,
 		}
 		a.latestWitnessReady.Broadcast()
 	}()