From 125f8a8957e7e088f2169e756ea0024c7cf9ac18 Mon Sep 17 00:00:00 2001
From: Jianrong <wjrjerome@gmail.com>
Date: Sat, 19 Feb 2022 16:17:27 +1100
Subject: [PATCH] Split initialise v2 into two scenarios

---
 consensus/XDPoS/XDPoS.go                    | 23 ++++++++++++++-------
 consensus/XDPoS/engines/engine_v2/engine.go | 10 ++++++---
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/consensus/XDPoS/XDPoS.go b/consensus/XDPoS/XDPoS.go
index df2f283a9e..3dfb9efc27 100644
--- a/consensus/XDPoS/XDPoS.go
+++ b/consensus/XDPoS/XDPoS.go
@@ -314,11 +314,15 @@ func (x *XDPoS) GetMasternodesByNumber(chain consensus.ChainReader, blockNumber
 }
 
 func (x *XDPoS) YourTurn(chain consensus.ChainReader, parent *types.Header, signer common.Address) (bool, error) {
-	if x.config.V2.SwitchBlock != nil && parent.Number.Cmp(x.config.V2.SwitchBlock) == 0 {
-		err := x.initialV2(chain, parent)
-		if err != nil {
-			log.Error("[YourTurn] Error when initialise v2", "Error", err, "ParentBlock", parent)
-			return false, err
+	if x.config.V2.SwitchBlock != nil && parent.Number.Cmp(x.config.V2.SwitchBlock) != -1 {
+		if parent.Number.Cmp(x.config.V2.SwitchBlock) == 0 {
+			err := x.initialV2FromLastV1(chain, parent)
+			if err != nil {
+				log.Error("[YourTurn] Error while initilising first v2 block from the last v1 block", "ParentBlockHash", parent.Hash(), "Error", err)
+				return false, err
+			}
+		} else if parent.Number.Cmp(x.config.V2.SwitchBlock) == 1 { // TODO: XIN-147
+			log.Info("[YourTurn] Initilising v2 after sync or restarted", "currentBlockNum", chain.CurrentHeader().Number, "currentBlockHash", chain.CurrentHeader().Hash())
 		}
 	}
 	switch x.config.BlockConsensusVersion(big.NewInt(parent.Number.Int64() + 1)) {
@@ -481,12 +485,15 @@ func (x *XDPoS) GetCachedSigningTxs(hash common.Hash) (interface{}, bool) {
 	return x.signingTxsCache.Get(hash)
 }
 
-//V2
-func (x *XDPoS) initialV2(chain consensus.ChainReader, header *types.Header) error {
+// V2 specific helper function to initilise consensus engine variables
+func (x *XDPoS) initialV2FromLastV1(chain consensus.ChainReader, header *types.Header) error {
 	checkpointBlockNumber := header.Number.Uint64() - header.Number.Uint64()%x.config.Epoch
 	checkpointHeader := chain.GetHeaderByNumber(checkpointBlockNumber)
 	masternodes := x.EngineV1.GetMasternodesFromCheckpointHeader(checkpointHeader)
-	x.EngineV2.Initial(chain, header, masternodes)
+	err := x.EngineV2.Initial(chain, header, masternodes)
+	if err != nil {
+		return err
+	}
 	return nil
 }
 
diff --git a/consensus/XDPoS/engines/engine_v2/engine.go b/consensus/XDPoS/engines/engine_v2/engine.go
index edbbc1cfae..1ed03b3633 100644
--- a/consensus/XDPoS/engines/engine_v2/engine.go
+++ b/consensus/XDPoS/engines/engine_v2/engine.go
@@ -119,7 +119,7 @@ func (x *XDPoS_v2) SignHash(header *types.Header) (hash common.Hash) {
 func (x *XDPoS_v2) Initial(chain consensus.ChainReader, header *types.Header, masternodes []common.Address) error {
 	log.Info("[Initial] initial v2 related parameters")
 
-	if x.highestQuorumCert.ProposedBlockInfo.Round != 0 { //already initialized
+	if x.highestQuorumCert.ProposedBlockInfo.Round != 0 { // already initialized
 		log.Warn("[Initial] Already initialized")
 		return nil
 	}
@@ -128,7 +128,7 @@ func (x *XDPoS_v2) Initial(chain consensus.ChainReader, header *types.Header, ma
 	defer x.lock.Unlock()
 	// Check header if it is the first consensus v2 block, if so, assign initial values to current round and highestQC
 
-	log.Info("[Initial] highest QC for consensus v2 first block", "Block Num", header.Number.String(), "BlockHash", header.Hash())
+	log.Info("[Initial] highest QC for consensus v2 first block", "BlockNum", header.Number.String(), "BlockHash", header.Hash())
 	// Generate new parent blockInfo and put it into QC
 	blockInfo := &utils.BlockInfo{
 		Hash:   header.Hash(),
@@ -148,7 +148,11 @@ func (x *XDPoS_v2) Initial(chain consensus.ChainReader, header *types.Header, ma
 
 	snap := newSnapshot(lastGapNum, lastGapHeader.Hash(), x.currentRound, x.highestQuorumCert, masternodes)
 	x.snapshots.Add(snap.Hash, snap)
-	storeSnapshot(snap, x.db)
+	err := storeSnapshot(snap, x.db)
+	if err != nil {
+		log.Error("[Initial] Error while storo snapshot", "error", err)
+		return err
+	}
 
 	// Initial timeout
 	log.Info("[Initial] miner wait period", "period", x.config.WaitPeriod)