Relocate transaction verification

src/neo/Ledger/Blockchain.cs

@@ -26,6 +26,7 @@ public class Import { public IEnumerable<Block> Blocks; public bool Verify = tru
  public class ImportCompleted { }
  public class FillMemoryPool { public IEnumerable<Transaction> Transactions; }
  public class FillCompleted { }
+ internal class PreverifyCompleted { public Transaction Transaction; public VerifyResult Result; public bool Relay; }
  public class RelayResult { public IInventory Inventory; public VerifyResult Result; }
 
  public static readonly uint MillisecondsPerBlock = ProtocolSettings.Default.MillisecondsPerBlock;
@@ -58,6 +59,7 @@ public class RelayResult { public IInventory Inventory; public VerifyResult Resu
  private const int MaxTxToReverifyPerIdle = 10;
  private static readonly object lockObj = new object();
  private readonly NeoSystem system;
+ private readonly IActorRef txrouter;
  private readonly List<UInt256> header_index = new List<UInt256>();
  private uint stored_header_count = 0;
  private readonly Dictionary<UInt256, Block> block_cache = new Dictionary<UInt256, Block>();
@@ -103,6 +105,7 @@ static Blockchain()
  public Blockchain(NeoSystem system, IStore store)
  {
  this.system = system;
+ this.txrouter = Context.ActorOf(TransactionRouter.Props(system));
  this.MemPool = new MemoryPool(system, ProtocolSettings.Default.MemoryPoolMaxTransactions);
  this.Store = store;
  this.View = new ReadOnlyView(store);
@@ -302,20 +305,15 @@ private void OnFillMemoryPool(IEnumerable<Transaction> transactions)
 
  private void OnInventory(IInventory inventory, bool relay = true)
  {
- RelayResult rr = new RelayResult
+ VerifyResult result = inventory switch
  {
- Inventory = inventory,
- Result = inventory switch
- {
- Block block => OnNewBlock(block),
- Transaction transaction => OnNewTransaction(transaction),
- _ => OnNewInventory(inventory)
- }
+ Block block => OnNewBlock(block),
+ Transaction transaction => OnNewTransaction(transaction),
+ _ => OnNewInventory(inventory)
  };
- if (relay && rr.Result == VerifyResult.Succeed)
+ if (relay && result == VerifyResult.Succeed)
  system.LocalNode.Tell(new LocalNode.RelayDirectly { Inventory = inventory });
- Sender.Tell(rr);
- Context.System.EventStream.Publish(rr);
+ SendRelayResult(inventory, result);
  }
 
  private VerifyResult OnNewBlock(Block block)
@@ -360,6 +358,14 @@ private VerifyResult OnNewTransaction(Transaction transaction)
  return MemPool.TryAdd(transaction, currentSnapshot);
  }
 
+ private void OnPreverifyCompleted(PreverifyCompleted task)
+ {
+ if (task.Result == VerifyResult.Succeed)
+ OnInventory(task.Transaction, task.Relay);
+ else
+ SendRelayResult(task.Transaction, task.Result);
+ }
+
  protected override void OnReceive(object message)
  {
  switch (message)
@@ -373,22 +379,34 @@ protected override void OnReceive(object message)
  case Block block:
  OnInventory(block, false);
  break;
+ case Transaction tx:
+ OnTransaction(tx, true);
+ break;
  case Transaction[] transactions:
- {
- // This message comes from a mempool's revalidation, already relayed
- foreach (var tx in transactions) OnInventory(tx, false);
- break;
- }
+ // This message comes from a mempool's revalidation, already relayed
+ foreach (var tx in transactions) OnTransaction(tx, false);
+ break;
  case IInventory inventory:
  OnInventory(inventory);
  break;
+ case PreverifyCompleted task:
+ OnPreverifyCompleted(task);
+ break;
  case Idle _:
  if (MemPool.ReVerifyTopUnverifiedTransactionsIfNeeded(MaxTxToReverifyPerIdle, currentSnapshot))
  Self.Tell(Idle.Instance, ActorRefs.NoSender);
  break;
  }
  }
 
+ private void OnTransaction(Transaction tx, bool relay)
+ {
+ if (ContainsTransaction(tx.Hash))
+ SendRelayResult(tx, VerifyResult.AlreadyExists);
+ else
+ txrouter.Tell(new TransactionRouter.Task { Transaction = tx, Relay = relay }, Sender);
+ }
+
  private void Persist(Block block)
  {
  using (SnapshotView snapshot = GetSnapshot())
@@ -507,6 +525,17 @@ private void SaveHeaderHashList(SnapshotView snapshot = null)
  }
  }
 
+ private void SendRelayResult(IInventory inventory, VerifyResult result)
+ {
+ RelayResult rr = new RelayResult
+ {
+ Inventory = inventory,
+ Result = result
+ };
+ Sender.Tell(rr);
+ Context.System.EventStream.Publish(rr);
+ }
+
  private void UpdateCurrentSnapshot()
  {
  Interlocked.Exchange(ref currentSnapshot, GetSnapshot())?.Dispose();

src/neo/Ledger/MemoryPool.cs

@@ -271,7 +271,7 @@ internal VerifyResult TryAdd(Transaction tx, StoreView snapshot)
  _txRwLock.EnterWriteLock();
  try
  {
- VerifyResult result = tx.Verify(snapshot, VerificationContext);
+ VerifyResult result = tx.VerifyStateDependent(snapshot, VerificationContext);
  if (result != VerifyResult.Succeed) return result;
 
  _unsortedTransactions.Add(tx.Hash, poolItem);
@@ -425,7 +425,7 @@ private int ReverifyTransactions(SortedSet<PoolItem> verifiedSortedTxPool,
  // Since unverifiedSortedTxPool is ordered in an ascending manner, we take from the end.
  foreach (PoolItem item in unverifiedSortedTxPool.Reverse().Take(count))
  {
- if (item.Tx.VerifyForEachBlock(snapshot, VerificationContext) == VerifyResult.Succeed)
+ if (item.Tx.VerifyStateDependent(snapshot, VerificationContext) == VerifyResult.Succeed)
  {
  reverifiedItems.Add(item);
  VerificationContext.AddTransaction(item.Tx);

src/neo/Ledger/TransactionRouter.cs

@@ -0,0 +1,35 @@
+using Akka.Actor;
+using Akka.Routing;
+using Neo.Network.P2P.Payloads;
+using System;
+
+namespace Neo.Ledger
+{
+ internal class TransactionRouter : UntypedActor
+ {
+ public class Task { public Transaction Transaction; public bool Relay; }
+
+ private readonly IActorRef blockchain;
+
+ public TransactionRouter(NeoSystem system)
+ {
+ this.blockchain = system.Blockchain;
+ }
+
+ protected override void OnReceive(object message)
+ {
+ if (!(message is Task task)) return;
+ blockchain.Tell(new Blockchain.PreverifyCompleted
+ {
+ Transaction = task.Transaction,
+ Result = task.Transaction.VerifyStateIndependent(),
+ Relay = task.Relay
+ }, Sender);
+ }
+
+ internal static Props Props(NeoSystem system)
+ {
+ return Akka.Actor.Props.Create(() => new TransactionRouter(system)).WithRouter(new SmallestMailboxPool(Environment.ProcessorCount));
+ }
+ }
+}

src/neo/Network/P2P/Payloads/Transaction.cs

@@ -281,7 +281,7 @@ bool IInventory.Verify(StoreView snapshot)
  return Verify(snapshot, null) == VerifyResult.Succeed;
  }
 
- public virtual VerifyResult VerifyForEachBlock(StoreView snapshot, TransactionVerificationContext context)
+ public virtual VerifyResult VerifyStateDependent(StoreView snapshot, TransactionVerificationContext context)
  {
  if (ValidUntilBlock <= snapshot.Height || ValidUntilBlock > snapshot.Height + MaxValidUntilBlockIncrement)
  return VerifyResult.Expired;
@@ -294,24 +294,27 @@ public virtual VerifyResult VerifyForEachBlock(StoreView snapshot, TransactionVe
  foreach (TransactionAttribute attribute in Attributes)
  if (!attribute.Verify(snapshot, this))
  return VerifyResult.Invalid;
- if (hashes.Length != Witnesses.Length) return VerifyResult.Invalid;
- for (int i = 0; i < hashes.Length; i++)
- {
- if (Witnesses[i].VerificationScript.Length > 0) continue;
- if (snapshot.Contracts.TryGet(hashes[i]) is null) return VerifyResult.Invalid;
- }
+ long net_fee = NetworkFee - Size * NativeContract.Policy.GetFeePerByte(snapshot);
+ if (!this.VerifyWitnesses(snapshot, net_fee, WitnessFlag.StateDependent))
+ return VerifyResult.Invalid;
+ return VerifyResult.Succeed;
+ }
+
+ public virtual VerifyResult VerifyStateIndependent()
+ {
+ if (Size > MaxTransactionSize)
+ return VerifyResult.Invalid;
+ if (!this.VerifyWitnesses(null, NetworkFee, WitnessFlag.StateIndependent))
+ return VerifyResult.Invalid;
  return VerifyResult.Succeed;
  }
 
  public virtual VerifyResult Verify(StoreView snapshot, TransactionVerificationContext context)
  {
- VerifyResult result = VerifyForEachBlock(snapshot, context);
+ VerifyResult result = VerifyStateIndependent();
  if (result != VerifyResult.Succeed) return result;
- if (Size > MaxTransactionSize) return VerifyResult.Invalid;
- long net_fee = NetworkFee - Size * NativeContract.Policy.GetFeePerByte(snapshot);
- if (net_fee < 0) return VerifyResult.InsufficientFunds;
- if (!this.VerifyWitnesses(snapshot, net_fee)) return VerifyResult.Invalid;
- return VerifyResult.Succeed;
+ result = VerifyStateDependent(snapshot, context);
+ return result;
  }
 
  public StackItem ToStackItem(ReferenceCounter referenceCounter)

src/neo/Network/P2P/Payloads/Witness.cs

@@ -11,6 +11,8 @@ public class Witness : ISerializable
  public byte[] InvocationScript;
  public byte[] VerificationScript;
 
+ internal long GasConsumed { get; set; }
+
  private UInt160 _scriptHash;
  public virtual UInt160 ScriptHash
  {
@@ -24,6 +26,8 @@ public virtual UInt160 ScriptHash
  }
  }
 
+ public bool StateDependent => VerificationScript.Length == 0;
+
  public int Size => InvocationScript.GetVarSize() + VerificationScript.GetVarSize();
 
  void ISerializable.Deserialize(BinaryReader reader)

src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs

@@ -286,13 +286,19 @@ private void OnGetHeadersMessageReceived(GetBlockByIndexPayload payload)
 
  private void OnInventoryReceived(IInventory inventory)
  {
- system.TaskManager.Tell(inventory);
- if (inventory is Transaction transaction)
- system.Consensus?.Tell(transaction);
- system.Blockchain.Tell(inventory, ActorRefs.NoSender);
  pendingKnownHashes.Remove(inventory.Hash);
  knownHashes.Add(inventory.Hash);
- if (inventory is Block b) UpdateLastBlockIndex(b.Index, false);
+ system.TaskManager.Tell(inventory);
+ system.Blockchain.Tell(inventory, ActorRefs.NoSender);
+ switch (inventory)
+ {
+ case Transaction transaction:
+ system.Consensus?.Tell(transaction);
+ break;
+ case Block block:
+ UpdateLastBlockIndex(block.Index, false);
+ break;
+ }
  }
 
  private void OnInvMessageReceived(InvPayload payload)

src/neo/SmartContract/Helper.cs

@@ -129,7 +129,7 @@ public static UInt160 ToScriptHash(this ReadOnlySpan<byte> script)
  return new UInt160(Crypto.Hash160(script));
  }
 
- internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snapshot, long gas)
+ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snapshot, long gas, WitnessFlag filter = WitnessFlag.All)
  {
  if (gas < 0) return false;
  if (gas > MaxVerificationGas) gas = MaxVerificationGas;
@@ -146,6 +146,14 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
  if (hashes.Length != verifiable.Witnesses.Length) return false;
  for (int i = 0; i < hashes.Length; i++)
  {
+ WitnessFlag flag = verifiable.Witnesses[i].StateDependent ? WitnessFlag.StateDependent : WitnessFlag.StateIndependent;
+ if (!filter.HasFlag(flag))
+ {
+ gas -= verifiable.Witnesses[i].GasConsumed;
+ if (gas < 0) return false;
+ continue;
+ }
+
  int offset;
  ContractMethodDescriptor init = null;
  byte[] verification = verifiable.Witnesses[i].VerificationScript;
@@ -164,14 +172,16 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
  if (hashes[i] != verifiable.Witnesses[i].ScriptHash) return false;
  offset = 0;
  }
- using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Verification, verifiable, snapshot.Clone(), gas))
+ using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Verification, verifiable, snapshot?.Clone(), gas))
  {
- ExecutionContext context = engine.LoadScript(verification, CallFlags.None, offset);
+ CallFlags callFlags = verifiable.Witnesses[i].StateDependent ? CallFlags.AllowStates : CallFlags.None;
+ ExecutionContext context = engine.LoadScript(verification, callFlags, offset);
  if (init != null) engine.LoadContext(context.Clone(init.Offset), false);
  engine.LoadScript(verifiable.Witnesses[i].InvocationScript, CallFlags.None);
  if (engine.Execute() == VMState.FAULT) return false;
  if (engine.ResultStack.Count != 1 || !engine.ResultStack.Pop().GetBoolean()) return false;
  gas -= engine.GasConsumed;
+ verifiable.Witnesses[i].GasConsumed = engine.GasConsumed;
  }
  }
  return true;

src/neo/SmartContract/WitnessFlag.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Neo.SmartContract
+{
+ [Flags]
+ internal enum WitnessFlag : byte
+ {
+ None = 0,
+
+ StateIndependent = 0b00000001,
+ StateDependent = 0b00000010,
+
+ All = StateIndependent | StateDependent
+ }
+}