Optimize mempool message

neo/Ledger/Blockchain.cs

@@ -364,7 +364,7 @@ private void OnNewHeaders(Header[] headers)
             system.TaskManager.Tell(new TaskManager.HeaderTaskCompleted(), Sender);
         }
 
-        private RelayResultReason OnNewTransaction(Transaction transaction)
+        private RelayResultReason OnNewTransaction(Transaction transaction, bool relay)
         {
             if (ContainsTransaction(transaction.Hash))
                 return RelayResultReason.AlreadyExists;
@@ -377,8 +377,8 @@ private RelayResultReason OnNewTransaction(Transaction transaction)
 
             if (!MemPool.TryAdd(transaction.Hash, transaction))
                 return RelayResultReason.OutOfMemory;
-
-            system.LocalNode.Tell(new LocalNode.RelayDirectly { Inventory = transaction });
+            if (relay)
+                system.LocalNode.Tell(new LocalNode.RelayDirectly { Inventory = transaction });
             return RelayResultReason.Succeed;
         }
 
@@ -405,8 +405,14 @@ protected override void OnReceive(object message)
                 case Block block:
                     Sender.Tell(OnNewBlock(block));
                     break;
+                case Transaction[] transactions:
+                    {
+                        // This message comes from a mempool's revalidation, already relayed
+                        foreach (var tx in transactions) OnNewTransaction(tx, false);
+                        break;
+                    }
                 case Transaction transaction:
-                    Sender.Tell(OnNewTransaction(transaction));
+                    Sender.Tell(OnNewTransaction(transaction, true));
                     break;
                 case ConsensusPayload payload:
                     Sender.Tell(OnNewConsensus(payload));

neo/Ledger/MemoryPool.cs

@@ -360,9 +360,14 @@ internal void UpdatePoolForBlockPersisted(Block block, Snapshot snapshot)
 
                 if (policyChanged)
                 {
+                    var tx = new List<Transaction>();
                     foreach (PoolItem item in _unverifiedSortedTransactions.Reverse())
                         if (item.Tx.FeePerByte >= _feePerByte)
-                            _system.Blockchain.Tell(item.Tx, ActorRefs.NoSender);
+                            tx.Add(item.Tx);
+
+                    if (tx.Count > 0)
+                        _system.Blockchain.Tell(tx.ToArray(), ActorRefs.NoSender);
+
                     _unverifiedTransactions.Clear();
                     _unverifiedSortedTransactions.Clear();
                 }