add confirmed loopup

eth/api_backend.go

@@ -56,8 +56,9 @@ import (
 
 // EthApiBackend implements ethapi.Backend for full nodes
 type EthApiBackend struct {
-	eth *Ethereum
+	eth   *Ethereum
-	gpo *gasprice.Oracle
+	gpo   *gasprice.Oracle
+	XDPoS *XDPoS.XDPoS
 }
 
 func (b *EthApiBackend) ChainConfig() *params.ChainConfig {
@@ -81,6 +82,22 @@ func (b *EthApiBackend) HeaderByNumber(ctx context.Context, blockNr rpc.BlockNum
 	// Otherwise resolve and return the block
 	if blockNr == rpc.LatestBlockNumber {
 		return b.eth.blockchain.CurrentBlock().Header(), nil
+	} else if blockNr == rpc.ConfirmedBlockNumber {
+		if b.eth.chainConfig.XDPoS == nil {
+			return nil, errors.New("PoW does not support confirmed block loopup")
+		}
+		current := b.eth.blockchain.CurrentBlock().Header()
+		if b.eth.blockchain.Config().XDPoS.BlockConsensusVersion(
+			current.Number,
+			current.Extra,
+			XDPoS.ExtraFieldCheck,
+		) == params.ConsensusEngineVersion2 {
+			// TO CHECK: why calling config in XDPoS is blocked (not field and method)
+			confirmedHash := b.XDPoS.EngineV2.GetLatestCommittedBlockInfo().Hash
+			return b.eth.blockchain.GetHeaderByHash(confirmedHash), nil
+		} else {
+			return nil, errors.New("PoS V1 does not support confirmed block loopup")
+		}
 	}
 	return b.eth.blockchain.GetHeaderByNumber(uint64(blockNr)), nil
 }
@@ -93,6 +110,22 @@ func (b *EthApiBackend) BlockByNumber(ctx context.Context, blockNr rpc.BlockNumb
 	// Otherwise resolve and return the block
 	if blockNr == rpc.LatestBlockNumber {
 		return b.eth.blockchain.CurrentBlock(), nil
+	} else if blockNr == rpc.ConfirmedBlockNumber {
+		if b.eth.chainConfig.XDPoS == nil {
+			return nil, errors.New("PoW does not support confirmed block loopup")
+		}
+		current := b.eth.blockchain.CurrentBlock().Header()
+		if b.eth.blockchain.Config().XDPoS.BlockConsensusVersion(
+			current.Number,
+			current.Extra,
+			XDPoS.ExtraFieldCheck,
+		) == params.ConsensusEngineVersion2 {
+			// TO CHECK: why calling config in XDPoS is blocked (not field and method)
+			confirmedHash := b.XDPoS.EngineV2.GetLatestCommittedBlockInfo().Hash
+			return b.eth.blockchain.GetBlockByHash(confirmedHash), nil
+		} else {
+			return nil, errors.New("PoS V1 does not support confirmed block loopup")
+		}
 	}
 	return b.eth.blockchain.GetBlockByNumber(uint64(blockNr)), nil
 }

eth/backend.go

@@ -216,7 +216,11 @@ func New(ctx *node.ServiceContext, config *Config, XDCXServ *XDCx.XDCX, lendingS
 	eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.engine, ctx.GetConfig().AnnounceTxs)
 	eth.miner.SetExtra(makeExtraData(config.ExtraData))
 
-	eth.ApiBackend = &EthApiBackend{eth, nil}
+	if eth.chainConfig.XDPoS != nil {
+		eth.ApiBackend = &EthApiBackend{eth, nil, eth.engine.(*XDPoS.XDPoS)}
+	} else {
+		eth.ApiBackend = &EthApiBackend{eth, nil, nil}
+	}
 	gpoParams := config.GPO
 	if gpoParams.Default == nil {
 		gpoParams.Default = config.GasPrice

rpc/types.go

@@ -120,10 +120,11 @@ type BlockNumber int64
 type EpochNumber int64
 
 const (
-	PendingBlockNumber  = BlockNumber(-2)
+	ConfirmedBlockNumber = BlockNumber(-3)
-	LatestBlockNumber   = BlockNumber(-1)
+	PendingBlockNumber   = BlockNumber(-2)
-	EarliestBlockNumber = BlockNumber(0)
+	LatestBlockNumber    = BlockNumber(-1)
-	LatestEpochNumber   = EpochNumber(-1)
+	EarliestBlockNumber  = BlockNumber(0)
+	LatestEpochNumber    = EpochNumber(-1)
 )
 
 // UnmarshalJSON parses the given JSON fragment into a BlockNumber. It supports:
@@ -144,6 +145,8 @@ func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
 	case "pending":
 		*bn = PendingBlockNumber
 		return nil
+	case "confirmed":
+		*bn = ConfirmedBlockNumber
 	}
 
 	blckNum, err := hexutil.DecodeUint64(input)