From ff850c5e170a8a132132de9aea6168b0668125aa Mon Sep 17 00:00:00 2001
From: Shargon <shargon@gmail.com>
Date: Tue, 3 Mar 2020 07:40:06 +0100
Subject: [PATCH] Remove parallel verification (#1429)

---
 src/neo/Ledger/Blockchain.cs                | 37 +++------------------
 src/neo/Network/P2P/Payloads/Transaction.cs | 11 ++----
 2 files changed, 8 insertions(+), 40 deletions(-)

diff --git a/src/neo/Ledger/Blockchain.cs b/src/neo/Ledger/Blockchain.cs
index 9090a5b339..65bba7bee0 100644
--- a/src/neo/Ledger/Blockchain.cs
+++ b/src/neo/Ledger/Blockchain.cs
@@ -27,7 +27,6 @@ public class Import { public IEnumerable<Block> Blocks; public bool Verify = tru
         public class ImportCompleted { }
         public class FillMemoryPool { public IEnumerable<Transaction> Transactions; }
         public class FillCompleted { }
-        private class ParallelVerified { public Transaction Transaction; public bool ShouldRelay; public RelayResultReason VerifyResult; }
 
         public static readonly uint MillisecondsPerBlock = ProtocolSettings.Default.MillisecondsPerBlock;
         public const uint DecrementInterval = 2000000;
@@ -407,39 +406,16 @@ private void OnNewTransaction(Transaction transaction, bool relay)
             else if (!MemPool.CanTransactionFitInPool(transaction))
                 reason = RelayResultReason.OutOfMemory;
             else
-                reason = transaction.VerifyForEachBlock(currentSnapshot, MemPool.SendersFeeMonitor.GetSenderFee(transaction.Sender));
-            if (reason == RelayResultReason.Succeed)
-            {
-                Task.Run(() =>
-                {
-                    return new ParallelVerified
-                    {
-                        Transaction = transaction,
-                        ShouldRelay = relay,
-                        VerifyResult = transaction.VerifyParallelParts(currentSnapshot)
-                    };
-                }).PipeTo(Self, Sender);
-            }
-            else
-            {
-                Sender.Tell(reason);
-            }
-        }
+                reason = transaction.Verify(currentSnapshot, MemPool.SendersFeeMonitor.GetSenderFee(transaction.Sender));
 
-        private void OnParallelVerified(ParallelVerified parallelVerified)
-        {
-            RelayResultReason reason = parallelVerified.VerifyResult;
             if (reason == RelayResultReason.Succeed)
             {
-                if (View.ContainsTransaction(parallelVerified.Transaction.Hash))
-                    reason = RelayResultReason.AlreadyExists;
-                else if (!MemPool.CanTransactionFitInPool(parallelVerified.Transaction))
+                if (!MemPool.TryAdd(transaction.Hash, transaction))
                     reason = RelayResultReason.OutOfMemory;
-                else if (!MemPool.TryAdd(parallelVerified.Transaction.Hash, parallelVerified.Transaction))
-                    reason = RelayResultReason.OutOfMemory;
-                else if (parallelVerified.ShouldRelay)
-                    system.LocalNode.Tell(new LocalNode.RelayDirectly { Inventory = parallelVerified.Transaction });
+                else if (relay)
+                    system.LocalNode.Tell(new LocalNode.RelayDirectly { Inventory = transaction });
             }
+
             Sender.Tell(reason);
         }
 
@@ -475,9 +451,6 @@ protected override void OnReceive(object message)
                 case Transaction transaction:
                     OnNewTransaction(transaction, true);
                     break;
-                case ParallelVerified parallelVerified:
-                    OnParallelVerified(parallelVerified);
-                    break;
                 case ConsensusPayload payload:
                     Sender.Tell(OnNewConsensus(payload));
                     break;
diff --git a/src/neo/Network/P2P/Payloads/Transaction.cs b/src/neo/Network/P2P/Payloads/Transaction.cs
index 2b6523a6aa..e511e17c94 100644
--- a/src/neo/Network/P2P/Payloads/Transaction.cs
+++ b/src/neo/Network/P2P/Payloads/Transaction.cs
@@ -266,13 +266,6 @@ bool IInventory.Verify(StoreView snapshot)
             return Verify(snapshot, BigInteger.Zero) == RelayResultReason.Succeed;
         }
 
-        public virtual RelayResultReason Verify(StoreView snapshot, BigInteger totalSenderFeeFromPool)
-        {
-            RelayResultReason result = VerifyForEachBlock(snapshot, totalSenderFeeFromPool);
-            if (result != RelayResultReason.Succeed) return result;
-            return VerifyParallelParts(snapshot);
-        }
-
         public virtual RelayResultReason VerifyForEachBlock(StoreView snapshot, BigInteger totalSenderFeeFromPool)
         {
             if (ValidUntilBlock <= snapshot.Height || ValidUntilBlock > snapshot.Height + MaxValidUntilBlockIncrement)
@@ -292,8 +285,10 @@ public virtual RelayResultReason VerifyForEachBlock(StoreView snapshot, BigInteg
             return RelayResultReason.Succeed;
         }
 
-        public RelayResultReason VerifyParallelParts(StoreView snapshot)
+        public virtual RelayResultReason Verify(StoreView snapshot, BigInteger totalSenderFeeFromPool)
         {
+            RelayResultReason result = VerifyForEachBlock(snapshot, totalSenderFeeFromPool);
+            if (result != RelayResultReason.Succeed) return result;
             int size = Size;
             if (size > MaxTransactionSize) return RelayResultReason.Invalid;
             long net_fee = NetworkFee - size * NativeContract.Policy.GetFeePerByte(snapshot);