From: apolloww <32606824+apolloww@users.noreply.github.com>
Date: Mon, 8 Jul 2019 05:42:55 +0000 (+0800)
Subject: keep last irreversible block on the main chain (#245)
X-Git-Tag: v1.0.5~174
X-Git-Url: http://git.osdn.net/view?p=bytom%2Fvapor.git;a=commitdiff_plain;h=3bf61490e8df4a17777877b56176ce608f4ccc26

keep last irreversible block on the main chain (#245)

* keep last irreversible block on the main chain

Only update the LIB pointer when newly irreversible block is on the main
chain. Emit warning otherwise.

* save updated block header
---

diff --git a/netsync/chainmgr/block_keeper.go b/netsync/chainmgr/block_keeper.go
index d1407e95..24b4ef37 100644
--- a/netsync/chainmgr/block_keeper.go
+++ b/netsync/chainmgr/block_keeper.go
@@ -190,7 +190,7 @@ func (bk *blockKeeper) syncWorker() {
 				continue
 			}
 
-			if err := bk.peers.BroadcastNewStatus(bk.chain.BestBlockHeader(), bk.chain.BestIrreversibleHeader()); err != nil {
+			if err := bk.peers.BroadcastNewStatus(bk.chain.BestBlockHeader(), bk.chain.LastIrreversibleHeader()); err != nil {
 				log.WithFields(log.Fields{"module": logModule, "err": err}).Error("fail on syncWorker broadcast new status")
 			}
 		case <-bk.quit:
diff --git a/netsync/chainmgr/handle.go b/netsync/chainmgr/handle.go
index 2a77d013..6e373899 100644
--- a/netsync/chainmgr/handle.go
+++ b/netsync/chainmgr/handle.go
@@ -25,7 +25,7 @@ const (
 // Chain is the interface for Bytom core
 type Chain interface {
 	BestBlockHeader() *types.BlockHeader
-	BestIrreversibleHeader() *types.BlockHeader
+	LastIrreversibleHeader() *types.BlockHeader
 	BestBlockHeight() uint64
 	GetBlockByHash(*bc.Hash) (*types.Block, error)
 	GetBlockByHeight(uint64) (*types.Block, error)
@@ -351,7 +351,7 @@ func (m *Manager) SendStatus(peer peers.BasePeer) error {
 		return errors.New("invalid peer")
 	}
 
-	if err := p.SendStatus(m.chain.BestBlockHeader(), m.chain.BestIrreversibleHeader()); err != nil {
+	if err := p.SendStatus(m.chain.BestBlockHeader(), m.chain.LastIrreversibleHeader()); err != nil {
 		m.peers.RemovePeer(p.ID())
 		return err
 	}
diff --git a/protocol/bbft.go b/protocol/bbft.go
index 03337a2e..a34e7030 100644
--- a/protocol/bbft.go
+++ b/protocol/bbft.go
@@ -98,7 +98,7 @@ func (c *Chain) ProcessBlockSignature(signature, xPub []byte, blockHash *bc.Hash
 
 // validateSign verify the signatures of block, and return the number of correct signature
 // if some signature is invalid, they will be reset to nil
-// if the block has not the signature of blocker, it will return error
+// if the block does not have the signature of blocker, it will return error
 func (c *Chain) validateSign(block *types.Block) error {
 	consensusNodeMap, err := c.getConsensusNodes(&block.PreviousBlockHash)
 	if err != nil {
@@ -225,11 +225,25 @@ func (c *Chain) updateBlockSignature(blockHeader *types.BlockHeader, nodeOrder u
 		return err
 	}
 
-	if c.isIrreversible(blockHeader) && blockHeader.Height > c.bestIrrBlockHeader.Height {
+	if !c.isIrreversible(blockHeader) || blockHeader.Height <= c.lastIrrBlockHeader.Height {
+		return nil
+	}
+
+	if c.InMainChain(blockHeader.Hash()) {
 		if err := c.store.SaveChainStatus(c.bestBlockHeader, blockHeader, []*types.BlockHeader{}, state.NewUtxoViewpoint(), []*state.ConsensusResult{}); err != nil {
 			return err
 		}
-		c.bestIrrBlockHeader = blockHeader
+
+		c.lastIrrBlockHeader = blockHeader
+	} else {
+		// block is on a forked chain
+		log.WithFields(log.Fields{"module": logModule}).Info("majority votes received on forked chain")
+		tail, err := c.traceLongestChainTail(blockHeader)
+		if err != nil {
+			return err
+		}
+
+		return c.reorganizeChain(tail)
 	}
 	return nil
 }
diff --git a/protocol/block.go b/protocol/block.go
index d03497b5..c1dc2651 100644
--- a/protocol/block.go
+++ b/protocol/block.go
@@ -110,7 +110,7 @@ func (c *Chain) connectBlock(block *types.Block) (err error) {
 		return err
 	}
 
-	irrBlockHeader := c.bestIrrBlockHeader
+	irrBlockHeader := c.lastIrrBlockHeader
 	if c.isIrreversible(&block.BlockHeader) && block.Height > irrBlockHeader.Height {
 		irrBlockHeader = &block.BlockHeader
 	}
@@ -167,7 +167,7 @@ func (c *Chain) reorganizeChain(blockHeader *types.BlockHeader) error {
 		log.WithFields(log.Fields{"module": logModule, "height": blockHeader.Height, "hash": blockHash.String()}).Debug("detach from mainchain")
 	}
 
-	irrBlockHeader := c.bestIrrBlockHeader
+	irrBlockHeader := c.lastIrrBlockHeader
 	for _, attachBlockHeader := range attachBlockHeaders {
 		attachHash := attachBlockHeader.Hash()
 		b, err := c.store.GetBlock(&attachHash)
@@ -205,7 +205,9 @@ func (c *Chain) reorganizeChain(blockHeader *types.BlockHeader) error {
 		log.WithFields(log.Fields{"module": logModule, "height": blockHeader.Height, "hash": blockHash.String()}).Debug("attach from mainchain")
 	}
 
-	if len(detachBlockHeaders) > 0 && detachBlockHeaders[len(detachBlockHeaders)-1].Height <= c.bestIrrBlockHeader.Height && irrBlockHeader.Height <= c.bestIrrBlockHeader.Height {
+	if len(detachBlockHeaders) > 0 &&
+		detachBlockHeaders[len(detachBlockHeaders)-1].Height <= c.lastIrrBlockHeader.Height &&
+		irrBlockHeader.Height <= c.lastIrrBlockHeader.Height {
 		return errors.New("rollback block below the height of irreversible block")
 	}
 	consensusResults = append(consensusResults, consensusResult.Fork())
diff --git a/protocol/protocol.go b/protocol/protocol.go
index 153312ca..80cb53a1 100644
--- a/protocol/protocol.go
+++ b/protocol/protocol.go
@@ -26,8 +26,8 @@ type Chain struct {
 	eventDispatcher *event.Dispatcher
 
 	cond               sync.Cond
-	bestBlockHeader    *types.BlockHeader
-	bestIrrBlockHeader *types.BlockHeader
+	bestBlockHeader    *types.BlockHeader // the last block on current main chain
+	lastIrrBlockHeader *types.BlockHeader // the last irreversible block
 }
 
 // NewChain returns a new Chain using store as the underlying storage.
@@ -56,7 +56,7 @@ func NewChain(store Store, txPool *TxPool, eventDispatcher *event.Dispatcher) (*
 		return nil, err
 	}
 
-	c.bestIrrBlockHeader, err = c.store.GetBlockHeader(storeStatus.IrreversibleHash)
+	c.lastIrrBlockHeader, err = c.store.GetBlockHeader(storeStatus.IrreversibleHash)
 	if err != nil {
 		return nil, err
 	}
@@ -102,7 +102,7 @@ func (c *Chain) BestBlockHeight() uint64 {
 	return c.bestBlockHeader.Height
 }
 
-// BestBlockHash return the hash of the chain tail block
+// BestBlockHash return the hash of the main chain tail block
 func (c *Chain) BestBlockHash() *bc.Hash {
 	c.cond.L.Lock()
 	defer c.cond.L.Unlock()
@@ -110,11 +110,11 @@ func (c *Chain) BestBlockHash() *bc.Hash {
 	return &bestHash
 }
 
-// BestIrreversibleHeader returns the chain best irreversible block header
-func (c *Chain) BestIrreversibleHeader() *types.BlockHeader {
+// LastIrreversibleHeader returns the chain last irreversible block header
+func (c *Chain) LastIrreversibleHeader() *types.BlockHeader {
 	c.cond.L.Lock()
 	defer c.cond.L.Unlock()
-	return c.bestIrrBlockHeader
+	return c.lastIrrBlockHeader
 }
 
 // BestBlockHeader returns the chain best block header
@@ -139,6 +139,33 @@ func (c *Chain) InMainChain(hash bc.Hash) bool {
 	return *blockHash == hash
 }
 
+// trace back to the tail of the chain from the given block header
+func (c *Chain) traceLongestChainTail(blockHeader *types.BlockHeader) (*types.BlockHeader, error) {
+	longestTail, workQueue := blockHeader, []*types.BlockHeader{blockHeader}
+
+	for len(workQueue) > 0 {
+		currentHeader := workQueue[0]
+		currentHash := currentHeader.Hash()
+		workQueue = workQueue[1:]
+		hashes, err := c.store.GetBlockHashesByHeight(currentHeader.Height + 1)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, h := range hashes {
+			if header, err := c.store.GetBlockHeader(h); err != nil {
+				return nil, err
+			} else if header.PreviousBlockHash == currentHash {
+				if longestTail.Height < header.Height {
+					longestTail = header
+				}
+				workQueue = append(workQueue, header)
+			}
+		}
+	}
+	return longestTail, nil
+}
+
 // This function must be called with mu lock in above level
 func (c *Chain) setState(blockHeader, irrBlockHeader *types.BlockHeader, mainBlockHeaders []*types.BlockHeader, view *state.UtxoViewpoint, consensusResults []*state.ConsensusResult) error {
 	if err := c.store.SaveChainStatus(blockHeader, irrBlockHeader, mainBlockHeaders, view, consensusResults); err != nil {
@@ -146,7 +173,7 @@ func (c *Chain) setState(blockHeader, irrBlockHeader *types.BlockHeader, mainBlo
 	}
 
 	c.bestBlockHeader = blockHeader
-	c.bestIrrBlockHeader = irrBlockHeader
+	c.lastIrrBlockHeader = irrBlockHeader
 
 	blockHash := blockHeader.Hash()
 	log.WithFields(log.Fields{"module": logModule, "height": blockHeader.Height, "hash": blockHash.String()}).Debug("chain best status has been update")
diff --git a/test/mock/chain.go b/test/mock/chain.go
index 2b85ff03..700891f5 100644
--- a/test/mock/chain.go
+++ b/test/mock/chain.go
@@ -37,7 +37,7 @@ func (c *Chain) BestBlockHeight() uint64 {
 	return c.bestBlockHeader.Height
 }
 
-func (c *Chain) BestIrreversibleHeader() *types.BlockHeader {
+func (c *Chain) LastIrreversibleHeader() *types.BlockHeader {
 	return c.bestBlockHeader
 }