core: more fix on light node synchronization (#32)

Fix gas calculation in governance contract.
Correctly register round height when processing pending blocks. We
should register the mapping when we get the pending block instead of
waiting for block confirmation.

3 files changed, 50 insertions, 67 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index f8d9bca9e..f4f4c425c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1596,7 +1596,7 @@ func (bc *BlockChain) processPendingBlock(
 		return nil, nil, nil, err
 	}
 
-	// Iterate over and process the individual transactions
+	// Iterate over and process the individual transactions.
 	for i, tx := range block.Transactions() {
 		pendingState.Prepare(tx.Hash(), block.Hash(), i)
 		receipt, _, err := ApplyTransaction(bc.chainConfig, bc, nil, gp, pendingState, header, tx, usedGas, bc.vmConfig)
@@ -1613,19 +1613,23 @@ func (bc *BlockChain) processPendingBlock(
 		return nil, nil, nil, fmt.Errorf("finalize error: %v", err)
 	}
 
+	if _, ok := bc.GetRoundHeight(newPendingBlock.Round()); !ok {
+		bc.storeRoundHeight(newPendingBlock.Round(), newPendingBlock.NumberU64())
+	}
+
 	proctime := time.Since(bstart)
 
-	// commit state to refresh stateCache
+	// Commit state to refresh stateCache.
 	_, err = pendingState.Commit(true)
 	if err != nil {
 		return nil, nil, nil, fmt.Errorf("pendingState commit error: %v", err)
 	}
 
-	// add into pending blocks
+	// Add into pending blocks.
 	bc.addPendingBlock(newPendingBlock, receipts)
 	events = append(events, BlockConfirmedEvent{newPendingBlock})
 
-	// start insert available pending blocks into db
+	// Start insert available pending blocks into db
 	for pendingHeight := bc.CurrentBlock().NumberU64() + 1; pendingHeight <= witness.Height; pendingHeight++ {
 		pendingIns, exist := bc.pendingBlocks[pendingHeight]
 		if !exist {
@@ -1646,8 +1650,9 @@ func (bc *BlockChain) processPendingBlock(
 
 		switch status {
 		case CanonStatTy:
-			log.Debug("Inserted new block", "number", pendingIns.block.Number(), "hash", pendingIns.block.Hash(), "uncles", len(pendingIns.block.Uncles()),
-				"txs", len(pendingIns.block.Transactions()), "gas", pendingIns.block.GasUsed(), "elapsed", common.PrettyDuration(time.Since(bstart)))
+			log.Debug("Inserted new block", "number", pendingIns.block.Number(), "hash", pendingIns.block.Hash(),
+				"uncles", len(pendingIns.block.Uncles()), "txs", len(pendingIns.block.Transactions()),
+				"gas", pendingIns.block.GasUsed(), "elapsed", common.PrettyDuration(time.Since(bstart)))
 
 			var allLogs []*types.Log
 			for _, r := range pendingIns.receipts {
@@ -1671,10 +1676,6 @@ func (bc *BlockChain) processPendingBlock(
 
 		cache, _ := bc.stateCache.TrieDB().Size()
 		stats.report([]*types.Block{pendingIns.block}, 0, cache)
-
-		if _, ok := bc.GetRoundHeight(pendingIns.block.Round()); !ok {
-			bc.storeRoundHeight(pendingIns.block.Round(), pendingHeight)
-		}
 	}
 	// Append a single chain head event if we've progressed the chain
 	if lastCanon != nil && bc.CurrentBlock().Hash() == lastCanon.Hash() {
diff --git a/core/genesis.go b/core/genesis.go
index 6eddf851d..5d8c54219 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -387,7 +387,7 @@ func DefaultGenesisBlock() *Genesis {
 		Timestamp:  1540024964,
 		Nonce:      0x42,
 		ExtraData:  hexutil.MustDecode("0x5765692d4e696e6720536f6e696320426f6a696520323031382d31302d32302e"),
-		GasLimit:   8000000,
+		GasLimit:   80000000,
 		Difficulty: big.NewInt(1),
 		Alloc:      decodePrealloc(mainnetAllocData),
 	}
@@ -399,7 +399,7 @@ func DefaultTestnetGenesisBlock() *Genesis {
 		Config:     params.TestnetChainConfig,
 		Nonce:      0x42,
 		ExtraData:  hexutil.MustDecode("0x3535353535353535353535353535353535353535353535353535353535353535"),
-		GasLimit:   8000000,
+		GasLimit:   80000000,
 		Difficulty: big.NewInt(1),
 		Alloc:      decodePrealloc(testnetAllocData),
 	}
diff --git a/core/vm/governance.go b/core/vm/governance.go
index cbc7f458f..b6a5038c5 100644
--- a/core/vm/governance.go
+++ b/core/vm/governance.go
@@ -1498,8 +1498,16 @@ func newGovernanceContract(evm *EVM, contract *Contract) *GovernanceContract {
 	}
 }
 
-func (g *GovernanceContract) penalize() {
-	g.contract.UseGas(g.contract.Gas)
+func (g *GovernanceContract) UseGas(gas uint64) ([]byte, error) {
+	if !g.contract.UseGas(gas) {
+		return nil, ErrOutOfGas
+	}
+	return nil, nil
+}
+
+func (g *GovernanceContract) penalize() ([]byte, error) {
+	g.UseGas(g.contract.Gas)
+	return nil, errExecutionReverted
 }
 
 func (g *GovernanceContract) inDKGSet(round *big.Int, nodeID coreTypes.NodeID) bool {
@@ -1532,16 +1540,14 @@ func (g *GovernanceContract) inDKGSet(round *big.Int, nodeID coreTypes.NodeID) b
 
 func (g *GovernanceContract) addDKGComplaint(round *big.Int, comp []byte) ([]byte, error) {
 	if round.Cmp(g.state.Round()) != 0 {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	caller := g.contract.Caller()
 
 	// Finalized caller is not allowed to propose complaint.
 	if g.state.DKGFinalized(round, caller) {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	// Calculate 2f
@@ -1556,34 +1562,29 @@ func (g *GovernanceContract) addDKGComplaint(round *big.Int, comp []byte) ([]byt
 
 	var dkgComplaint dkgTypes.Complaint
 	if err := rlp.DecodeBytes(comp, &dkgComplaint); err != nil {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	// DKGComplaint must belongs to someone in DKG set.
 	if !g.inDKGSet(round, dkgComplaint.ProposerID) {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	verified, _ := core.VerifyDKGComplaintSignature(&dkgComplaint)
 	if !verified {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	g.state.PushDKGComplaint(round, comp)
 
 	// Set this to relatively high to prevent spamming
-	g.contract.UseGas(10000000)
-	return nil, nil
+	return g.UseGas(5000000)
 }
 
 func (g *GovernanceContract) addDKGMasterPublicKey(round *big.Int, mpk []byte) ([]byte, error) {
 	// Can only add DKG master public key of current and next round.
 	if round.Cmp(new(big.Int).Add(g.state.Round(), big.NewInt(1))) > 0 {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	caller := g.contract.Caller()
@@ -1596,53 +1597,44 @@ func (g *GovernanceContract) addDKGMasterPublicKey(round *big.Int, mpk []byte) (
 
 	var dkgMasterPK dkgTypes.MasterPublicKey
 	if err := rlp.DecodeBytes(mpk, &dkgMasterPK); err != nil {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	// DKGMasterPublicKey must belongs to someone in DKG set.
 	if !g.inDKGSet(round, dkgMasterPK.ProposerID) {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	verified, _ := core.VerifyDKGMasterPublicKeySignature(&dkgMasterPK)
 	if !verified {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	g.state.PushDKGMasterPublicKey(round, mpk)
 
-	// DKG operation is expensive.
-	g.contract.UseGas(100000)
-	return nil, nil
+	return g.UseGas(100000)
 }
 
 func (g *GovernanceContract) addDKGFinalize(round *big.Int, finalize []byte) ([]byte, error) {
 	if round.Cmp(g.state.Round()) != 0 {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	caller := g.contract.Caller()
 
 	var dkgFinalize dkgTypes.Finalize
 	if err := rlp.DecodeBytes(finalize, &dkgFinalize); err != nil {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	// DKGFInalize must belongs to someone in DKG set.
 	if !g.inDKGSet(round, dkgFinalize.ProposerID) {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	verified, _ := core.VerifyDKGFinalizeSignature(&dkgFinalize)
 	if !verified {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	if !g.state.DKGFinalized(round, caller) {
@@ -1650,9 +1642,7 @@ func (g *GovernanceContract) addDKGFinalize(round *big.Int, finalize []byte) ([]
 		g.state.IncDKGFinalizedsCount(round)
 	}
 
-	// DKG operation is expensive.
-	g.contract.UseGas(100000)
-	return nil, nil
+	return g.UseGas(100000)
 }
 
 func (g *GovernanceContract) updateConfiguration(config *params.DexconConfig) ([]byte, error) {
@@ -1671,8 +1661,7 @@ func (g *GovernanceContract) stake(
 
 	// Reject invalid inputs.
 	if len(name) >= 32 || len(email) >= 32 || len(location) >= 32 || len(url) >= 128 {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	caller := g.contract.Caller()
@@ -1680,14 +1669,12 @@ func (g *GovernanceContract) stake(
 
 	// Need to stake at least minStake.
 	if g.contract.Value().Cmp(g.state.MinStake()) < 0 {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	// Can not stake if already staked.
 	if offset.Cmp(big.NewInt(0)) >= 0 {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	offset = g.state.NodesLength()
@@ -1702,8 +1689,7 @@ func (g *GovernanceContract) stake(
 	})
 	g.state.PutOffset(caller, offset)
 
-	g.contract.UseGas(21000)
-	return nil, nil
+	return g.UseGas(0)
 }
 
 func (g *GovernanceContract) unstake() ([]byte, error) {
@@ -1729,8 +1715,7 @@ func (g *GovernanceContract) unstake() ([]byte, error) {
 	// TODO(w): add this to debug trace so it shows up as internal transaction.
 	g.evm.Transfer(g.evm.StateDB, GovernanceContractAddress, caller, node.Staked)
 
-	g.contract.UseGas(21000)
-	return nil, nil
+	return g.UseGas(0)
 }
 
 func (g *GovernanceContract) proposeCRS(nextRound *big.Int, signedCRS []byte) ([]byte, error) {
@@ -1781,8 +1766,7 @@ func (g *GovernanceContract) proposeCRS(nextRound *big.Int, signedCRS []byte) ([
 		Signature: signedCRS,
 	}
 	if !dkgGPK.VerifySignature(coreCommon.Hash(prevCRS), signature) {
-		g.penalize()
-		return nil, errExecutionReverted
+		return g.penalize()
 	}
 
 	// Save new CRS into state and increase round.
@@ -1794,8 +1778,7 @@ func (g *GovernanceContract) proposeCRS(nextRound *big.Int, signedCRS []byte) ([
 
 	// To encourage DKG set to propose the correct value, correctly submitting
 	// this should cause nothing.
-	g.contract.UseGas(0)
-	return nil, nil
+	return g.UseGas(0)
 }
 
 func (g *GovernanceContract) transferOwnership(newOwner common.Address) ([]byte, error) {
@@ -1812,20 +1795,19 @@ func (g *GovernanceContract) snapshotRound(round, height *big.Int) ([]byte, erro
 	if g.evm.IsBlockProposer() {
 		realHeight, ok := g.evm.Context.GetRoundHeight(round.Uint64())
 		if !ok {
-			g.penalize()
-			return nil, errExecutionReverted
+			return g.penalize()
 		}
 
 		if height.Cmp(new(big.Int).SetUint64(realHeight)) != 0 {
-			g.penalize()
-			return nil, errExecutionReverted
+			return g.penalize()
 		}
 	}
 
 	// Only allow updating the next round.
 	nextRound := g.state.LenRoundHeight()
 	if round.Cmp(nextRound) != 0 {
-		g.penalize()
+		// No need to penalize, since the only possibility at this point is the
+		// round height is already snapshoted.
 		return nil, errExecutionReverted
 	}