Add role designation history

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

@@ -71,7 +71,7 @@ public override bool Verify(StoreView snapshot, Transaction tx)
             OracleRequest request = NativeContract.Oracle.GetRequest(snapshot, Id);
             if (request is null) return false;
             if (tx.NetworkFee + tx.SystemFee != request.GasForResponse) return false;
-            UInt160 oracleAccount = Blockchain.GetConsensusAddress(NativeContract.Designate.GetDesignatedByRole(snapshot, Role.Oracle));
+            UInt160 oracleAccount = Blockchain.GetConsensusAddress(NativeContract.Designate.GetDesignatedByRole(snapshot, Role.Oracle, snapshot.Height + 1));
             return tx.Signers.Any(p => p.Account.Equals(oracleAccount));
         }
     }

src/neo/SmartContract/Native/Designate/DesignateContract.cs

@@ -3,6 +3,7 @@
 using Neo.Cryptography;
 using Neo.Cryptography.ECC;
 using Neo.IO;
+using Neo.IO.Caching;
 using Neo.Ledger;
 using Neo.Persistence;
 using Neo.SmartContract.Manifest;
@@ -24,20 +25,18 @@ internal DesignateContract()
             Manifest.Features = ContractFeatures.HasStorage;
         }
 
-        internal override void Initialize(ApplicationEngine engine)
-        {
-            foreach (byte role in Enum.GetValues(typeof(Role)))
-            {
-                engine.Snapshot.Storages.Add(CreateStorageKey(role), new StorageItem(new NodeList()));
-            }
-        }
-
         [ContractMethod(0_01000000, CallFlags.AllowStates)]
-        public ECPoint[] GetDesignatedByRole(StoreView snapshot, Role role)
+        public ECPoint[] GetDesignatedByRole(StoreView snapshot, Role role, uint index)
         {
             if (!Enum.IsDefined(typeof(Role), role))
                 throw new ArgumentOutOfRangeException(nameof(role));
-            return snapshot.Storages[CreateStorageKey((byte)role)].GetInteroperable<NodeList>().ToArray();
+            if (snapshot.Height + 1 < index)
+                throw new ArgumentOutOfRangeException(nameof(index));
+            byte[] key = CreateStorageKey((byte)role).AddBigEndian(index).ToArray();
+            byte[] boundary = CreateStorageKey((byte)role).ToArray();
+            return snapshot.Storages.FindRange(key, boundary, SeekDirection.Backward)
+                .Select(u => u.Value.GetInteroperable<NodeList>().ToArray())
+                .FirstOrDefault() ?? System.Array.Empty<ECPoint>();
         }
 
         [ContractMethod(0, CallFlags.AllowModifyStates)]
@@ -47,19 +46,26 @@ private void DesignateAsRole(ApplicationEngine engine, Role role, ECPoint[] node
                 throw new ArgumentException();
             if (!Enum.IsDefined(typeof(Role), role))
                 throw new ArgumentOutOfRangeException(nameof(role));
-            if (!CheckCommittee(engine)) throw new InvalidOperationException();
-            NodeList list = engine.Snapshot.Storages.GetAndChange(CreateStorageKey((byte)role)).GetInteroperable<NodeList>();
-            list.Clear();
+            if (!CheckCommittee(engine))
+                throw new InvalidOperationException(nameof(DesignateAsRole));
+            if (engine.Snapshot.PersistingBlock is null)
+                throw new InvalidOperationException(nameof(DesignateAsRole));
+            uint index = engine.Snapshot.PersistingBlock.Index + 1;
+            var key = CreateStorageKey((byte)role).AddBigEndian(index);
+            if (engine.Snapshot.Storages.Contains(key))
+                throw new InvalidOperationException();
+            NodeList list = new NodeList();
             list.AddRange(nodes);
             list.Sort();
+            engine.Snapshot.Storages.Add(key, new StorageItem(list));
         }
 
         private class NodeList : List<ECPoint>, IInteroperable
         {
             public void FromStackItem(StackItem stackItem)
             {
                 foreach (StackItem item in (VM.Types.Array)stackItem)
-                    Add(ECPoint.DecodePoint(item.GetSpan(), ECCurve.Secp256r1));
+                    Add(item.GetSpan().AsSerializable<ECPoint>());
             }
 
             public StackItem ToStackItem(ReferenceCounter referenceCounter)

src/neo/SmartContract/Native/Oracle/OracleContract.cs

@@ -107,7 +107,7 @@ protected override void PostPersist(ApplicationEngine engine)
                 if (list.Count == 0) engine.Snapshot.Storages.Delete(key);
 
                 //Mint GAS for oracle nodes
-                nodes ??= NativeContract.Designate.GetDesignatedByRole(engine.Snapshot, Role.Oracle).Select(p => (Contract.CreateSignatureRedeemScript(p).ToScriptHash(), BigInteger.Zero)).ToArray();
+                nodes ??= NativeContract.Designate.GetDesignatedByRole(engine.Snapshot, Role.Oracle, engine.Snapshot.PersistingBlock.Index).Select(p => (Contract.CreateSignatureRedeemScript(p).ToScriptHash(), BigInteger.Zero)).ToArray();
                 if (nodes.Length > 0)
                 {
                     int index = (int)(response.Id % (ulong)nodes.Length);

tests/neo.UnitTests/Extensions/NativeContractExtensions.cs

@@ -38,7 +38,9 @@ public static StackItem Call(this NativeContract contract, StoreView snapshot, I
                 throw exception ?? new InvalidOperationException();
             }
 
-            return engine.ResultStack.Pop();
+            if (0 < engine.ResultStack.Count)
+                return engine.ResultStack.Pop();
+            return null;
         }
     }
 }

tests/neo.UnitTests/SmartContract/Native/UT_DesignateContract.cs

@@ -0,0 +1,70 @@
+using FluentAssertions;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Neo.Cryptography.ECC;
+using Neo.IO;
+using Neo.Ledger;
+using Neo.Network.P2P.Payloads;
+using Neo.SmartContract;
+using Neo.SmartContract.Native;
+using Neo.SmartContract.Native.Designate;
+using Neo.UnitTests.Extensions;
+using System.Linq;
+using System.Numerics;
+
+namespace Neo.UnitTests.SmartContract.Native
+{
+    [TestClass]
+    public class UT_DesignateContract
+    {
+        [TestInitialize]
+        public void TestSetup()
+        {
+            TestBlockchain.InitializeMockNeoSystem();
+        }
+
+        [TestMethod]
+        public void TestSetAndGet()
+        {
+            using var snapshot1 = Blockchain.Singleton.GetSnapshot();
+            snapshot1.PersistingBlock = new Block
+            {
+                Index = 0,
+            };
+            UInt160 committeeMultiSigAddr = NativeContract.NEO.GetCommitteeAddress(snapshot1);
+            ECPoint[] validators = NativeContract.NEO.ComputeNextBlockValidators(snapshot1);
+            var ret = NativeContract.Designate.Call(
+                snapshot1,
+                new Nep5NativeContractExtensions.ManualWitness(committeeMultiSigAddr),
+                "designateAsRole",
+                new ContractParameter(ContractParameterType.Integer) { Value = new BigInteger((int)Role.StateValidator) },
+                new ContractParameter(ContractParameterType.Array) { Value = validators.Select(p => new ContractParameter(ContractParameterType.ByteArray) { Value = p.ToArray() }).ToList() }
+            );
+            snapshot1.Commit();
+            using var snapshot2 = Blockchain.Singleton.GetSnapshot();
+            ret = NativeContract.Designate.Call(
+                snapshot2,
+                "getDesignatedByRole",
+                new ContractParameter(ContractParameterType.Integer) { Value = new BigInteger((int)Role.StateValidator) },
+                new ContractParameter(ContractParameterType.Integer) { Value = new BigInteger(1u) }
+            );
+            ret.Should().BeOfType<VM.Types.Array>();
+            (ret as VM.Types.Array).Count.Should().Be(7);
+            (ret as VM.Types.Array)[0].GetSpan().ToHexString().Should().Be(validators[0].ToArray().ToHexString());
+            (ret as VM.Types.Array)[1].GetSpan().ToHexString().Should().Be(validators[1].ToArray().ToHexString());
+            (ret as VM.Types.Array)[2].GetSpan().ToHexString().Should().Be(validators[2].ToArray().ToHexString());
+            (ret as VM.Types.Array)[3].GetSpan().ToHexString().Should().Be(validators[3].ToArray().ToHexString());
+            (ret as VM.Types.Array)[4].GetSpan().ToHexString().Should().Be(validators[4].ToArray().ToHexString());
+            (ret as VM.Types.Array)[5].GetSpan().ToHexString().Should().Be(validators[5].ToArray().ToHexString());
+            (ret as VM.Types.Array)[6].GetSpan().ToHexString().Should().Be(validators[6].ToArray().ToHexString());
+
+            ret = NativeContract.Designate.Call(
+                snapshot2,
+                "getDesignatedByRole",
+                new ContractParameter(ContractParameterType.Integer) { Value = new BigInteger((int)Role.StateValidator) },
+                new ContractParameter(ContractParameterType.Integer) { Value = new BigInteger(0) }
+            );
+            ret.Should().BeOfType<VM.Types.Array>();
+            (ret as VM.Types.Array).Count.Should().Be(0);
+        }
+    }
+}