Oracle: Optimize the filter payment (#1610)

* Optimize the payment of the filter * Add comment * Remove foreach * Remove foreach in wallet
neo-project · Apr 25, 2020 · d9c032b · d9c032b
1 parent 04d4578
commit d9c032b
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Showing 3 changed files with 13 additions and 38 deletions.
diff --git a/src/neo/Oracle/OracleResponse.cs b/src/neo/Oracle/OracleResponse.cs
@@ -9,7 +9,6 @@ namespace Neo.Oracle
     public class OracleResponse : ISerializable
     {
         private UInt160 _hash;
-        private bool _alreadyPayed;
 
         /// <summary>
         /// Request hash
@@ -49,25 +48,6 @@ public UInt160 Hash
 
         public int Size => UInt160.Length + sizeof(byte) + Result.GetVarSize() + sizeof(long);
 
-        /// <summary>
-        /// Filter cost that it could be consumed only once
-        /// </summary>
-        public long FilterCostOnce()
-        {
-            if (_alreadyPayed) return 0;
-
-            _alreadyPayed = true;
-            return FilterCost;
-        }
-
-        /// <summary>
-        /// Reset the _alreadyPayed flag
-        /// </summary>
-        public void ResetFilterCostOnce()
-        {
-            _alreadyPayed = false;
-        }
-
         /// <summary>
         /// Create error result
         /// </summary>

diff --git a/src/neo/SmartContract/Native/Oracle/OracleContract.cs b/src/neo/SmartContract/Native/Oracle/OracleContract.cs
@@ -82,19 +82,24 @@ public bool ContainsResponse(StoreView snapshot, UInt256 txHash)
         /// <summary>
         /// Consume Oracle Response
         /// </summary>
-        /// <param name="snapshot">Snapshot</param>
+        /// <param name="engine">Engine</param>
         /// <param name="txHash">Transaction Hash</param>
-        public OracleExecutionCache ConsumeOracleResponse(StoreView snapshot, UInt256 txHash)
+        public OracleExecutionCache ConsumeOracleResponse(ApplicationEngine engine, UInt256 txHash)
         {
             StorageKey key = CreateStorageKey(Prefix_OracleResponse, txHash.ToArray());
-            StorageItem storage = snapshot.Storages.TryGet(key);
+            StorageItem storage = engine.Snapshot.Storages.TryGet(key);
             if (storage == null) return null;
 
             OracleExecutionCache ret = storage.Value.AsSerializable<OracleExecutionCache>();
 
             // It should be cached by the ApplicationEngine so we can save space removing it
 
-            snapshot.Storages.Delete(key);
+            engine.Snapshot.Storages.Delete(key);
+
+            // Pay for the filter
+
+            if (!engine.AddGas(ret.FilterCost)) throw new ArgumentException("OutOfGas");
+
             return ret;
         }
 
@@ -348,7 +353,7 @@ private StackItem Get(ApplicationEngine engine, Array args)
                 {
                     // Read Oracle Response
 
-                    engine.OracleCache = Oracle.ConsumeOracleResponse(engine.Snapshot, tx.Hash);
+                    engine.OracleCache = Oracle.ConsumeOracleResponse(engine, tx.Hash);
 
                     // If it doesn't exist, fault
 
@@ -415,8 +420,6 @@ private StackItem Get(ApplicationEngine engine, Array args)
             {
                 // Add the gas filter cost
 
-                if (!engine.AddGas(response.FilterCostOnce())) return false;
-
                 return response.Result ?? StackItem.Null;
             }
 

diff --git a/src/neo/Wallets/Wallet.cs b/src/neo/Wallets/Wallet.cs
@@ -334,17 +334,6 @@ private Transaction MakeTransaction(StoreView snapshot, byte[] script, Transacti
                     Cosigners = cosigners
                 };
 
-                if (oracleCache != null)
-                {
-                    // We need to reset if we already consumed the fiter price
-                    // otherwise we can have a wrong gas computation
-
-                    foreach (var entry in oracleCache.Responses)
-                    {
-                        entry.ResetFilterCostOnce();
-                    }
-                }
-
                 // will try to execute 'transfer' script to check if it works
                 using (ApplicationEngine engine = ApplicationEngine.Run(script, snapshot.Clone(), tx, testMode: true, oracle: oracleCache))
                 {
@@ -357,6 +346,9 @@ private Transaction MakeTransaction(StoreView snapshot, byte[] script, Transacti
 
                     if (oracleRequests?.Count > 0)
                     {
+                        // Increase filter cost
+
+                        tx.SystemFee += oracleCache.FilterCost;
                         tx.Version = TransactionVersion.OracleRequest;
 
                         if (oracle == OracleWalletBehaviour.OracleWithAssert)