XDC block producer

src/Nethermind/Nethermind.Xdc/XdcBlockProducer.cs

@@ -0,0 +1,102 @@
+// SPDX-FileCopyrightText: 2025 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using Nethermind.Blockchain;
+using Nethermind.Config;
+using Nethermind.Consensus;
+using Nethermind.Consensus.Processing;
+using Nethermind.Consensus.Producers;
+using Nethermind.Consensus.Transactions;
+using Nethermind.Core;
+using Nethermind.Core.Crypto;
+using Nethermind.Core.Specs;
+using Nethermind.Evm.State;
+using Nethermind.Evm.Tracing;
+using Nethermind.Int256;
+using Nethermind.Logging;
+using Nethermind.Xdc.RLP;
+using Nethermind.Xdc.Spec;
+using Nethermind.Xdc.Types;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Nethermind.Xdc;
+internal class XdcBlockProducer : BlockProducerBase
+{
+    private readonly IEpochSwitchManager epochSwitchManager;
+    private readonly ISnapshotManager snapshotManager;
+    private readonly XdcContext xdcContext;
+    private readonly ISealer sealer;
+    private readonly ISpecProvider specProvider;
+    private readonly ILogManager logManager;
+    private static readonly ExtraConsensusDataDecoder _extraConsensusDataDecoder = new();
+
+    public XdcBlockProducer(IEpochSwitchManager epochSwitchManager, ISnapshotManager snapshotManager, XdcContext xdcContext, ITxSource txSource, IBlockchainProcessor processor, ISealer sealer, IBlockTree blockTree, IWorldState stateProvider, IGasLimitCalculator? gasLimitCalculator, ITimestamper? timestamper, ISpecProvider specProvider, ILogManager logManager, IDifficultyCalculator? difficultyCalculator, IBlocksConfig? blocksConfig) : base(txSource, processor, sealer, blockTree, stateProvider, gasLimitCalculator, timestamper, specProvider, logManager, difficultyCalculator, blocksConfig)
+    {
+        this.epochSwitchManager = epochSwitchManager;
+        this.snapshotManager = snapshotManager;
+        this.xdcContext = xdcContext;
+        this.sealer = sealer;
+        this.specProvider = specProvider;
+        this.logManager = logManager;
+    }
+
+    protected override BlockHeader PrepareBlockHeader(BlockHeader parent, PayloadAttributes? payloadAttributes)
+    {
+        if (parent is not XdcBlockHeader xdcParent)
+            throw new ArgumentException("Only XDC header are supported.");
+
+        QuorumCertificate highestCert = xdcContext.HighestQC;
+        var currentRound = xdcContext.CurrentRound;
+
+        //TODO maybe some sanity checks here for round and hash
+
+        byte[] extra = [2, .. _extraConsensusDataDecoder.Encode(new ExtraFieldsV2(currentRound, highestCert)).Bytes];
+
+        Address blockAuthor = sealer.Address;
+        XdcBlockHeader xdcBlockHeader = new(
+            parent.Hash!,
+            Keccak.OfAnEmptySequenceRlp,
+            blockAuthor,
+            UInt256.Zero,
+            parent.Number + 1,
+            XdcConstants.TargetGasLimit,
+            0,
+            extra)
+        {
+            Author = blockAuthor,
+        };
+
+        IXdcReleaseSpec spec = specProvider.GetXdcSpec(xdcBlockHeader, currentRound);
+
+        xdcBlockHeader.Timestamp = parent.Timestamp + (ulong)spec.MinePeriod;
+
+        parent.Difficulty = 1;
+
+        xdcBlockHeader.BaseFeePerGas = BaseFeeCalculator.Calculate(parent, spec);
+
+        if (epochSwitchManager.IsEpochSwitch(xdcBlockHeader, out _))
+        {
+            (Address[] masternodes, Address[] penalties) = snapshotManager.CalculateNextEpochMasternodes(xdcBlockHeader, spec);
+
+            xdcBlockHeader.Validators = new byte[masternodes.Length * Address.Size];
+
+            for (int i = 0; i < masternodes.Length; i++)
+            {
+                Array.Copy(masternodes[i].Bytes, 0, xdcBlockHeader.Validators, i * Address.Size, Address.Size);
+            }
+
+            xdcBlockHeader.Penalties = new byte[penalties.Length * Address.Size];
+
+            for (int i = 0; i < penalties.Length; i++)
+            {
+                Array.Copy(penalties[i].Bytes, 0, xdcBlockHeader.Penalties, i * Address.Size, Address.Size);
+            }
+        }
+        return xdcBlockHeader;
+    }
+}

src/Nethermind/Nethermind.Xdc/XdcConstants.cs

@@ -26,6 +26,8 @@ internal static class XdcConstants
 
     public static readonly int InMemoryRound2Epochs = 65536;   // One epoch ~ 0.5h, 65536 epochs ~ 3.7y, ~10MB memory
 
+    public const long TargetGasLimit = 84000000; // XDC default gas limit per block
+
     // --- Compile-time constants ---
     public const int InMemorySnapshots = 128;       // Number of recent vote snapshots to keep in memory
     public const int BlockSignersCacheLimit = 9000;