*: introduce StateRootInHeader

Close #1526.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>

Author: AnnaShaleva

src/Neo/NeoSystem.cs

@@ -164,6 +164,7 @@ public NeoSystem(ProtocolSettings settings, IStoreProvider storageProvider, stri
         {
             Header = new Header
             {
+                Version = settings.IsHardforkEnabled(Hardfork.HF_Faun, 0) ? (uint)BlockVersion.V1 : (uint)BlockVersion.V0,
                 PrevHash = UInt256.Zero,
                 MerkleRoot = UInt256.Zero,
                 Timestamp = (new DateTime(2016, 7, 15, 15, 8, 21, DateTimeKind.Utc)).ToTimestampMS(),
@@ -331,5 +332,16 @@ public bool ContainsConflictHash(UInt256 hash, IEnumerable<UInt160> signers)
         {
             return NativeContract.Ledger.ContainsConflictHash(StoreView, hash, signers, this.GetMaxTraceableBlocks());
         }
+
+        /// <summary>
+        /// Returns index of the latest block persisted to native Ledger contract.
+        /// </summary>
+        /// <returns>
+        /// Index of the latest persisted block.
+        /// </returns>
+        public uint CurrentIndex()
+        {
+            return NativeContract.Ledger.CurrentIndex(StoreView);
+        }
     }
 }

src/Neo/Network/P2P/Payloads/Block.cs

@@ -80,6 +80,11 @@ public sealed class Block : IEquatable<Block>, IInventory
         /// </summary>
         public UInt160 NextConsensus => Header.NextConsensus;
 
+        /// <summary>
+        /// MPT root hash calculated after the previous block is persisted.
+        /// </summary>
+        public UInt256 PrevStateRoot => Header.PrevStateRoot;
+
         /// <summary>
         /// The witness of the block.
         /// </summary>

src/Neo/Network/P2P/Payloads/BlockVersion.cs

@@ -0,0 +1,28 @@
+// Copyright (C) 2015-2025 The Neo Project.
+//
+// BlockVersion.cs file belongs to the neo project and is free
+// software distributed under the MIT software license, see the
+// accompanying file LICENSE in the main directory of the
+// repository or http://www.opensource.org/licenses/mit-license.php
+// for more details.
+//
+// Redistribution and use in source and binary forms with or without
+// modifications are permitted.
+
+namespace Neo.Network.P2P.Payloads
+{
+    /// <summary>
+    /// Represents the block version.
+    /// </summary>
+    public enum BlockVersion : byte
+    {
+        /// <summary>
+        /// Initial block version.
+        /// </summary>
+        V0,
+        /// <summary>
+        /// Block version 1 which adds PrevStateRoot field to the header.
+        /// </summary>
+        V1,
+    }
+}

src/Neo/Network/P2P/Payloads/Header.cs

@@ -35,6 +35,7 @@ public sealed class Header : IEquatable<Header>, IVerifiable
         private uint index;
         private byte primaryIndex;
         private UInt160 nextConsensus;
+        private UInt256 prevStateRoot;
 
         /// <summary>
         /// The witness of the block.
@@ -113,6 +114,15 @@ public UInt160 NextConsensus
             set { nextConsensus = value; _hash = null; }
         }
 
+        /// <summary>
+        /// MPT root hash got after the previous block processing.
+        /// </summary>
+        public UInt256 PrevStateRoot
+        {
+            get => prevStateRoot;
+            set { prevStateRoot = value; _hash = null; }
+        }
+
         private UInt256 _hash = null;
 
         /// <inheritdoc/>
@@ -137,6 +147,7 @@ public UInt256 Hash
             sizeof(uint) +      // Index
             sizeof(byte) +      // PrimaryIndex
             UInt160.Length +    // NextConsensus
+            (version == (uint)BlockVersion.V0 ? 0 : UInt256.Length) + // PrevStateRoot
             (Witness is null ? 1 : 1 + Witness.Size); // Witness, cannot be null for valid header
 
         Witness[] IVerifiable.Witnesses
@@ -166,14 +177,16 @@ void IVerifiable.DeserializeUnsigned(ref MemoryReader reader)
         {
             _hash = null;
             version = reader.ReadUInt32();
-            if (version > 0) throw new FormatException($"`version`({version}) in Header must be 0");
+            if (version > (uint)BlockVersion.V1) throw new FormatException($"`version`({version}) in Header must be 0 or 1");
             prevHash = reader.ReadSerializable<UInt256>();
             merkleRoot = reader.ReadSerializable<UInt256>();
             timestamp = reader.ReadUInt64();
             nonce = reader.ReadUInt64();
             index = reader.ReadUInt32();
             primaryIndex = reader.ReadByte();
             nextConsensus = reader.ReadSerializable<UInt160>();
+            if (version == (uint)BlockVersion.V1)
+                prevStateRoot = reader.ReadSerializable<UInt256>();
         }
 
         public bool Equals(Header other)
@@ -217,6 +230,8 @@ void IVerifiable.SerializeUnsigned(BinaryWriter writer)
             writer.Write(index);
             writer.Write(primaryIndex);
             writer.Write(nextConsensus);
+            if (version == (uint)BlockVersion.V1)
+                writer.Write(prevStateRoot);
         }
 
         /// <summary>
@@ -238,13 +253,17 @@ public JObject ToJson(ProtocolSettings settings)
             json["primary"] = primaryIndex;
             json["nextconsensus"] = nextConsensus.ToAddress(settings.AddressVersion);
             json["witnesses"] = new JArray(Witness.ToJson());
+            if (version == (uint)BlockVersion.V1)
+                json["previousstateroot"] = prevStateRoot.ToString();
             return json;
         }
 
         internal bool Verify(ProtocolSettings settings, DataCache snapshot)
         {
             if (primaryIndex >= settings.ValidatorsCount)
                 return false;
+            if (version != (uint)GetExpectedVersion(settings))
+                return false;
             TrimmedBlock prev = NativeContract.Ledger.GetTrimmedBlock(snapshot, prevHash);
             if (prev is null) return false;
             if (prev.Index + 1 != index) return false;
@@ -258,6 +277,8 @@ internal bool Verify(ProtocolSettings settings, DataCache snapshot, HeaderCache
         {
             Header prev = headerCache.Last;
             if (prev is null) return Verify(settings, snapshot);
+            if (version != (uint)GetExpectedVersion(settings))
+                return false;
             if (primaryIndex >= settings.ValidatorsCount)
                 return false;
             if (prev.Hash != prevHash) return false;
@@ -266,6 +287,11 @@ internal bool Verify(ProtocolSettings settings, DataCache snapshot, HeaderCache
             return this.VerifyWitness(settings, snapshot, prev.nextConsensus, Witness, 3_00000000L, out _);
         }
 
+        private BlockVersion GetExpectedVersion(ProtocolSettings settings)
+        {
+            return settings.IsHardforkEnabled(Hardfork.HF_Faun, Index) ? BlockVersion.V1 : BlockVersion.V0;
+        }
+
         public Header Clone()
         {
             return new Header()
@@ -278,6 +304,7 @@ public Header Clone()
                 Index = index,
                 PrimaryIndex = primaryIndex,
                 NextConsensus = nextConsensus,
+                PrevStateRoot = prevStateRoot,
                 Witness = Witness?.Clone(),
                 _hash = _hash
             };

src/Neo/SmartContract/Native/TrimmedBlock.cs

@@ -15,6 +15,7 @@
 using Neo.VM;
 using Neo.VM.Types;
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using Array = Neo.VM.Types.Array;
@@ -110,8 +111,7 @@ void IInteroperable.FromStackItem(StackItem stackItem)
 
         StackItem IInteroperable.ToStackItem(IReferenceCounter referenceCounter)
         {
-            return new Array(referenceCounter,
-            [
+            var block = new List<StackItem>() {
                 // Computed properties
                 Header.Hash.ToArray(),
 
@@ -125,9 +125,14 @@ StackItem IInteroperable.ToStackItem(IReferenceCounter referenceCounter)
                 Header.PrimaryIndex,
                 Header.NextConsensus.ToArray(),
 
-                // Block properties
-                Hashes.Length
-            ]);
+            };
+            if (Header.Version == (uint)BlockVersion.V1)
+                block.Add(Header.PrevStateRoot.ToArray());
+
+            // Block properties
+            block.Add(Hashes.Length);
+
+            return new Array(referenceCounter, block);
         }
     }
 }

src/Plugins/DBFTPlugin/Consensus/ConsensusContext.MakePayload.cs

@@ -115,7 +115,8 @@ public ExtensiblePayload MakePrepareRequest()
                 PrevHash = Block.PrevHash,
                 Timestamp = Block.Timestamp,
                 Nonce = Block.Nonce,
-                TransactionHashes = TransactionHashes
+                TransactionHashes = TransactionHashes,
+                PrevStateRoot = Block.PrevStateRoot,
             });
         }
 
@@ -141,6 +142,7 @@ public ExtensiblePayload MakeRecoveryMessage()
                     Nonce = Block.Nonce,
                     BlockIndex = Block.Index,
                     ValidatorIndex = Block.PrimaryIndex,
+                    PrevStateRoot = Block.PrevStateRoot,
                     TransactionHashes = TransactionHashes
                 };
             }

src/Plugins/DBFTPlugin/Consensus/ConsensusContext.cs

@@ -199,16 +199,19 @@ public void Reset(byte viewNumber)
                 Snapshot?.Dispose();
                 Snapshot = neoSystem.GetSnapshotCache();
                 uint height = NativeContract.Ledger.CurrentIndex(Snapshot);
+                var isFaun = neoSystem.Settings.IsHardforkEnabled(Hardfork.HF_Faun, height + 1);
                 Block = new Block
                 {
                     Header = new Header
                     {
+                        Version = isFaun ? (uint)BlockVersion.V1 : (uint)BlockVersion.V0,
                         PrevHash = NativeContract.Ledger.CurrentHash(Snapshot),
                         Index = height + 1,
                         NextConsensus = Contract.GetBFTAddress(
                             NeoToken.ShouldRefreshCommittee(height + 1, neoSystem.Settings.CommitteeMembersCount) ?
                             NativeContract.NEO.ComputeNextBlockValidators(Snapshot, neoSystem.Settings) :
-                            NativeContract.NEO.GetNextBlockValidators(Snapshot, neoSystem.Settings.ValidatorsCount))
+                            NativeContract.NEO.GetNextBlockValidators(Snapshot, neoSystem.Settings.ValidatorsCount)),
+                        PrevStateRoot = isFaun ? StateService.StatePlugin.GetStateRootHash(height) : null
                     }
                 };
                 TimePerBlock = neoSystem.GetTimePerBlock();
@@ -294,6 +297,8 @@ public void Deserialize(ref MemoryReader reader)
             Block.Header.NextConsensus = reader.ReadSerializable<UInt160>();
             if (Block.NextConsensus.Equals(UInt160.Zero))
                 Block.Header.NextConsensus = null;
+            if (Block.Version == (uint)BlockVersion.V1)
+                Block.Header.PrevStateRoot = reader.ReadSerializable<UInt256>();
             ViewNumber = reader.ReadByte();
             TransactionHashes = reader.ReadSerializableArray<UInt256>(ushort.MaxValue);
             Transaction[] transactions = reader.ReadSerializableArray<Transaction>(ushort.MaxValue);
@@ -320,6 +325,8 @@ public void Serialize(BinaryWriter writer)
             writer.Write(Block.Nonce);
             writer.Write(Block.PrimaryIndex);
             writer.Write(Block.NextConsensus ?? UInt160.Zero);
+            if (Block.Version == (uint)BlockVersion.V1)
+                writer.Write(Block.PrevStateRoot);
             writer.Write(ViewNumber);
             writer.Write(TransactionHashes ?? Array.Empty<UInt256>());
             writer.Write(Transactions?.Values.ToArray() ?? Array.Empty<Transaction>());

src/Plugins/DBFTPlugin/Consensus/ConsensusService.OnMessage.cs

@@ -79,7 +79,7 @@ private void OnPrepareRequestReceived(ExtensiblePayload payload, PrepareRequest
         {
             if (context.RequestSentOrReceived || context.NotAcceptingPayloadsDueToViewChanging) return;
             if (message.ValidatorIndex != context.Block.PrimaryIndex || message.ViewNumber != context.ViewNumber) return;
-            if (message.Version != context.Block.Version || message.PrevHash != context.Block.PrevHash) return;
+            if (message.Version != context.Block.Version || message.PrevHash != context.Block.PrevHash || message.PrevStateRoot != context.Block.PrevStateRoot) return;
             if (message.TransactionHashes.Length > neoSystem.Settings.MaxTransactionsPerBlock) return;
             Log($"{nameof(OnPrepareRequestReceived)}: height={message.BlockIndex} view={message.ViewNumber} index={message.ValidatorIndex} tx={message.TransactionHashes.Length}");
             if (message.Timestamp <= context.PrevHeader.Timestamp || message.Timestamp > TimeProvider.Current.UtcNow.AddMilliseconds(8 * context.TimePerBlock.TotalMilliseconds).ToTimestampMS())

src/Plugins/DBFTPlugin/DBFTPlugin.csproj

@@ -12,6 +12,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\Neo.ConsoleService\Neo.ConsoleService.csproj" />
+    <ProjectReference Include="..\StateService\StateService.csproj" />
   </ItemGroup>
 
   <ItemGroup>

src/Plugins/DBFTPlugin/DBFTPlugin.json

@@ -7,5 +7,8 @@
     "MaxBlockSize": 2097152,
     "MaxBlockSystemFee": 150000000000,
     "UnhandledExceptionPolicy": "StopNode"
-  }
+  },
+  "Dependency": [
+    "StateService"
+  ]
 }