Add Fee Ratio

src/neo/Ledger/Blockchain.cs

@@ -446,6 +446,7 @@ private void Persist(Block block)
                     all_application_executed.Add(application_executed);
                 }
                 snapshot.Blocks.Add(block.Hash, block.Trim());
+                uint ratio = NativeContract.Policy.GetFeeRatio(snapshot);
                 StoreView clonedSnapshot = snapshot.Clone();
                 // Warning: Do not write into variable snapshot directly. Write into variable clonedSnapshot and commit instead.
                 foreach (Transaction tx in block.Transactions)
@@ -459,7 +460,7 @@ private void Persist(Block block)
                     clonedSnapshot.Transactions.Add(tx.Hash, state);
                     clonedSnapshot.Transactions.Commit();
 
-                    using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Application, tx, clonedSnapshot, tx.SystemFee))
+                    using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Application, tx, clonedSnapshot, tx.SystemFee * ratio))
                     {
                         engine.LoadScript(tx.Script);
                         state.VMState = engine.Execute();

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

@@ -294,7 +294,7 @@ public virtual VerifyResult VerifyStateDependent(StoreView snapshot, Transaction
             foreach (TransactionAttribute attribute in Attributes)
                 if (!attribute.Verify(snapshot, this))
                     return VerifyResult.Invalid;
-            long net_fee = NetworkFee - Size * NativeContract.Policy.GetFeePerByte(snapshot);
+            long net_fee = NetworkFee * NativeContract.Policy.GetFeeRatio(snapshot) - Size * NativeContract.Policy.GetFeePerByte(snapshot);
             if (!this.VerifyWitnesses(snapshot, net_fee, WitnessFlag.StateDependent))
                 return VerifyResult.Invalid;
             return VerifyResult.Succeed;

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

@@ -22,7 +22,7 @@ public class Witness : ISerializable
         public byte[] InvocationScript;
         public byte[] VerificationScript;
 
-        internal long GasConsumed { get; set; }
+        internal long GasConsumedWithRatio { get; set; }
 
         private UInt160 _scriptHash;
         public virtual UInt160 ScriptHash

src/neo/SmartContract/ApplicationEngine.cs

@@ -3,6 +3,7 @@
 using Neo.Network.P2P.Payloads;
 using Neo.Persistence;
 using Neo.Plugins;
+using Neo.SmartContract.Native;
 using Neo.VM;
 using Neo.VM.Types;
 using System;
@@ -42,7 +43,7 @@ private class InvocationState
 
         private static IApplicationEngineProvider applicationEngineProvider;
         private static Dictionary<uint, InteropDescriptor> services;
-        private readonly long gas_amount;
+        private readonly long gas_amount_with_ratio;
         private List<NotifyEventArgs> notifications;
         private List<IDisposable> disposables;
         private readonly Dictionary<UInt160, int> invocationCounter = new Dictionary<UInt160, int>();
@@ -53,8 +54,9 @@ private class InvocationState
         public TriggerType Trigger { get; }
         public IVerifiable ScriptContainer { get; }
         public StoreView Snapshot { get; }
-        public long GasConsumed { get; private set; } = 0;
-        public long GasLeft => gas_amount - GasConsumed;
+        public long GasConsumedWithRatio = 0;
+        public long GasConsumed => GasConsumedWithRatio / NativeContract.Policy.GetFeeRatio(Snapshot);
+        public long GasLeft => (gas_amount_with_ratio - GasConsumedWithRatio) / NativeContract.Policy.GetFeeRatio(Snapshot);
         public Exception FaultException { get; private set; }
         public UInt160 CurrentScriptHash => CurrentContext?.GetScriptHash();
         public UInt160 CallingScriptHash => CurrentContext?.GetState<ExecutionContextState>().CallingScriptHash;
@@ -66,13 +68,13 @@ protected ApplicationEngine(TriggerType trigger, IVerifiable container, StoreVie
             this.Trigger = trigger;
             this.ScriptContainer = container;
             this.Snapshot = snapshot;
-            this.gas_amount = gas;
+            this.gas_amount_with_ratio = gas;
         }
 
         protected internal void AddGas(long gas)
         {
-            GasConsumed = checked(GasConsumed + gas);
-            if (GasConsumed > gas_amount)
+            GasConsumedWithRatio = checked(GasConsumedWithRatio + gas);
+            if (GasConsumedWithRatio > gas_amount_with_ratio)
                 throw new InvalidOperationException("Insufficient GAS.");
         }
 

src/neo/SmartContract/Helper.cs

@@ -133,7 +133,8 @@ public static UInt160 ToScriptHash(this ReadOnlySpan<byte> script)
         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;
+            if (snapshot is null) gas = MaxVerificationGas;
+            else if (gas > MaxVerificationGas) gas = MaxVerificationGas;
 
             UInt160[] hashes;
             try
@@ -150,7 +151,7 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
                 WitnessFlag flag = verifiable.Witnesses[i].StateDependent ? WitnessFlag.StateDependent : WitnessFlag.StateIndependent;
                 if (!filter.HasFlag(flag))
                 {
-                    gas -= verifiable.Witnesses[i].GasConsumed;
+                    gas -= verifiable.Witnesses[i].GasConsumedWithRatio;
                     if (gas < 0) return false;
                     continue;
                 }
@@ -192,8 +193,8 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
                     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;
+                    gas -= engine.GasConsumedWithRatio;
+                    verifiable.Witnesses[i].GasConsumedWithRatio = engine.GasConsumedWithRatio;
                 }
             }
             return true;

src/neo/SmartContract/Native/PolicyContract.cs

@@ -20,6 +20,7 @@ public sealed class PolicyContract : NativeContract
         private const byte Prefix_BlockedAccount = 15;
         private const byte Prefix_MaxBlockSize = 12;
         private const byte Prefix_MaxBlockSystemFee = 17;
+        private const byte Prefix_FeeRatio = 34;
 
         public PolicyContract()
         {
@@ -64,6 +65,14 @@ public bool IsBlocked(StoreView snapshot, UInt160 account)
             return snapshot.Storages.Contains(CreateStorageKey(Prefix_BlockedAccount).Add(account));
         }
 
+        [ContractMethod(0_01000000, CallFlags.AllowStates)]
+        public uint GetFeeRatio(StoreView snapshot)
+        {
+            StorageItem item = snapshot.Storages.TryGet(CreateStorageKey(Prefix_FeeRatio));
+            if (item is null) return 1;
+            return (uint)(BigInteger)item;
+        }
+
         [ContractMethod(0_03000000, CallFlags.AllowModifyStates)]
         private bool SetMaxBlockSize(ApplicationEngine engine, uint value)
         {
@@ -127,5 +136,15 @@ private bool UnblockAccount(ApplicationEngine engine, UInt160 account)
             engine.Snapshot.Storages.Delete(key);
             return true;
         }
+
+        [ContractMethod(0_03000000, CallFlags.AllowModifyStates)]
+        private bool SetFeeRatio(ApplicationEngine engine, uint value)
+        {
+            if (value == 0) throw new ArgumentOutOfRangeException(nameof(value));
+            if (!CheckCommittee(engine)) return false;
+            StorageItem storage = engine.Snapshot.Storages.GetAndChange(CreateStorageKey(Prefix_FeeRatio), () => new StorageItem());
+            storage.Set(value);
+            return true;
+        }
     }
 }

src/neo/Wallets/Wallet.cs

@@ -405,7 +405,7 @@ public long CalculateNetworkFee(StoreView snapshot, Transaction tx)
                     if (engine.Execute() == VMState.FAULT) throw new ArgumentException($"Smart contract {contract.ScriptHash} verification fault.");
                     if (engine.ResultStack.Count != 1 || !engine.ResultStack.Pop().GetBoolean()) throw new ArgumentException($"Smart contract {contract.ScriptHash} returns false.");
 
-                    networkFee += engine.GasConsumed;
+                    networkFee += engine.GasConsumedWithRatio;
                 }
                 else if (witness_script.IsSignatureContract())
                 {
@@ -430,7 +430,7 @@ public long CalculateNetworkFee(StoreView snapshot, Transaction tx)
                 }
             }
             networkFee += size * NativeContract.Policy.GetFeePerByte(snapshot);
-            return networkFee;
+            return networkFee / NativeContract.Policy.GetFeeRatio(snapshot);
         }
 
         public bool Sign(ContractParametersContext context)

tests/neo.UnitTests/Network/P2P/Payloads/UT_Transaction.cs

@@ -5,6 +5,7 @@
 using Neo.IO.Json;
 using Neo.Ledger;
 using Neo.Network.P2P.Payloads;
+using Neo.Persistence;
 using Neo.SmartContract;
 using Neo.SmartContract.Native;
 using Neo.SmartContract.Native.Tokens;
@@ -1260,9 +1261,15 @@ public void Test_Verify()
                 var key = NativeContract.GAS.CreateStorageKey(20, acc.ScriptHash);
                 var entry = snapshot.Storages.GetAndChange(key, () => new StorageItem(new AccountState()));
 
-                entry.GetInteroperable<AccountState>().Balance = 10000 * NativeContract.GAS.Factor;
+                entry.GetInteroperable<AccountState>().Balance = NativeContract.GAS.Factor / 10;
+
+                snapshot.Commit();
 
+                //Change FeeRatio
+                StorageItem storage = snapshot.Storages.GetAndChange(new KeyBuilder(-3, 34), () => new StorageItem());
+                storage.Set(2);
                 snapshot.Commit();
+                NativeContract.Policy.GetFeeRatio(snapshot).Should().Be(2);
 
                 // Make transaction
 
@@ -1285,6 +1292,19 @@ public void Test_Verify()
 
                 tx.Witnesses = data.GetWitnesses();
                 tx.Verify(snapshot, new TransactionVerificationContext()).Should().Be(VerifyResult.Succeed);
+
+                using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Application, tx, snapshot, tx.SystemFee * NativeContract.Policy.GetFeeRatio(snapshot)))
+                {
+                    engine.LoadScript(tx.Script);
+                    VMState state = engine.Execute();
+                    Assert.AreEqual(state, VMState.HALT);
+                }
+
+                //Revert FeeRatio
+                storage = snapshot.Storages.GetAndChange(new KeyBuilder(-3, 34), () => new StorageItem());
+                storage.Set(1);
+                snapshot.Commit();
+                NativeContract.Policy.GetFeeRatio(snapshot).Should().Be(1);
             }
         }
     }