core, indexer, dex: fix DexconApp block deliver after synced (#122)

When starts a bp node to sync with the network, bc.chainLastHeight map
may not be initialized yet.
Just return error if we can not get chain last height when preparing
payload and verify block.

3 files changed, 16 insertions, 15 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index c5e2f6bf4..b4a2882dd 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -395,12 +395,13 @@ func (bc *BlockChain) GetCostInConfirmedBlocks(chainID uint32, address common.Ad
 	return cost, exist
 }
 
-func (bc *BlockChain) GetChainLastConfirmedHeight(chainID uint32) uint64 {
-	val, ok := bc.chainLastHeight.Load(chainID)
-	if !ok {
-		panic(fmt.Errorf("failed to get chain last height, chainID = %d", chainID))
+func (bc *BlockChain) GetChainLastConfirmedHeight(chainID uint32) (uint64, bool) {
+	val := uint64(0)
+	v, ok := bc.chainLastHeight.Load(chainID)
+	if ok {
+		val = v.(uint64)
 	}
-	return val.(uint64)
+	return val, ok
 }
 
 func (bc *BlockChain) GetAddressInfo(chainID uint32, address common.Address) (
diff --git a/dex/app.go b/dex/app.go
index d04b2afd6..c52a6c79b 100644
--- a/dex/app.go
+++ b/dex/app.go
@@ -177,11 +177,11 @@ func (d *DexconApp) preparePayload(ctx context.Context, position coreTypes.Posit
 
 	if position.Height != 0 {
 		// Check if chain block height is strictly increamental.
-		chainLastHeight := d.blockchain.GetChainLastConfirmedHeight(position.ChainID)
-		if chainLastHeight != position.Height-1 {
-			log.Error("Check confirmed block height fail",
-				"chain", position.ChainID, "height", position.Height-1, "cache height", chainLastHeight)
-			return nil, fmt.Errorf("check confirmed block height fail")
+		chainLastHeight, ok := d.blockchain.GetChainLastConfirmedHeight(position.ChainID)
+		if !ok || chainLastHeight != position.Height-1 {
+			log.Debug("Previous confirmed block not exists", "current pos", position.String(),
+				"prev height", chainLastHeight, "ok", ok)
+			return nil, fmt.Errorf("previous block not exists")
 		}
 	}
 
@@ -337,10 +337,10 @@ func (d *DexconApp) VerifyBlock(block *coreTypes.Block) coreTypes.BlockVerifySta
 	if block.Position.Height != 0 {
 		// Check if target block is the next height to be verified, we can only
 		// verify the next block in a given chain.
-		chainLastHeight := d.blockchain.GetChainLastConfirmedHeight(block.Position.ChainID)
-		if chainLastHeight != block.Position.Height-1 {
-			log.Error("Check confirmed block height fail", "chain", block.Position.ChainID,
-				"height", block.Position.Height-1, "cache height", chainLastHeight)
+		chainLastHeight, ok := d.blockchain.GetChainLastConfirmedHeight(block.Position.ChainID)
+		if !ok || chainLastHeight != block.Position.Height-1 {
+			log.Debug("Previous confirmed block not exists", "current pos", block.Position.String(),
+				"prev height", chainLastHeight, "ok", ok)
 			return coreTypes.VerifyRetryLater
 		}
 	}
diff --git a/indexer/blockchain.go b/indexer/blockchain.go
index 421535184..f41c05a15 100644
--- a/indexer/blockchain.go
+++ b/indexer/blockchain.go
@@ -42,7 +42,7 @@ type ReadOnlyBlockChain interface {
 	GetBlocksFromHash(common.Hash, int) (blocks []*types.Block)
 	GetBody(common.Hash) *types.Body
 	GetBodyRLP(common.Hash) rlp.RawValue
-	GetChainLastConfirmedHeight(uint32) uint64
+	GetChainLastConfirmedHeight(uint32) (uint64, bool)
 	GetConfirmedBlockByHash(uint32, coreCommon.Hash) (*coreTypes.Block, types.Transactions)
 	GetCostInConfirmedBlocks(uint32, common.Address) (*big.Int, bool)
 	GetGovStateByHash(common.Hash) (*types.GovState, error)