Optimize: more clearer parser for parameter Signers and Witness, and fix comments

Author: Wi1l-B0t

src/Plugins/RpcServer/ParameterConverter.cs

@@ -9,11 +9,15 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
+using Neo.Cryptography.ECC;
 using Neo.Json;
+using Neo.Extensions;
+using Neo.Network.P2P.Payloads;
 using Neo.Plugins.RpcServer.Model;
 using Neo.Wallets;
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using JToken = Neo.Json.JToken;
 
 namespace Neo.Plugins.RpcServer
@@ -138,6 +142,103 @@ private static RpcError CreateInvalidParamError<T>(JToken token)
         {
             return RpcError.InvalidParams.WithData($"Invalid {typeof(T)} value: {token}");
         }
+
+        /// <summary>
+        /// Create a SignersAndWitnesses from a JSON array.
+        /// Each item in the JSON array should be a JSON object with the following properties:
+        /// - "signer": A JSON object with the following properties:
+        ///   - "account": A hex-encoded UInt160 or a Base58Check address, required.
+        ///   - "scopes": A enum string representing the scopes(WitnessScope) of the signer, required.
+        ///   - "allowedcontracts": An array of hex-encoded UInt160, optional.
+        ///   - "allowedgroups": An array of hex-encoded ECPoint, optional.
+        ///   - "rules": An array of strings representing the rules(WitnessRule) of the signer, optional.
+        /// - "witness": A JSON object with the following properties:
+        ///   - "invocation": A base64-encoded string representing the invocation script, optional.
+        ///   - "verification": A base64-encoded string representing the verification script, optional.
+        /// </summary>
+        /// <param name="json">The JSON array to create a SignersAndWitnesses from.</param>
+        /// <param name="addressVersion">The address version to use for the signers.</param>
+        /// <returns>A SignersAndWitnesses object.</returns>
+        /// <exception cref="RpcException">Thrown when the JSON array is invalid.</exception>
+        internal static (Signer[] Signers, Witness[] Witnesses) ToSignersAndWitnesses(this JArray json, byte addressVersion)
+        {
+            var signers = json.ToSigners(addressVersion);
+            var witnesses = json.ToWitnesses();
+            return new(signers, witnesses);
+        }
+
+        /// <summary>
+        /// Create a Signer array from a JSON array.
+        /// Each item in the JSON array should be a JSON object with the following properties:
+        /// - "account": A hex-encoded UInt160 or a Base58Check address, required.
+        /// - "scopes": A enum string representing the scopes(WitnessScope) of the signer, required.
+        /// - "allowedcontracts": An array of hex-encoded UInt160, optional.
+        /// - "allowedgroups": An array of hex-encoded ECPoint, optional.
+        /// - "rules": An array of strings representing the rules(WitnessRule) of the signer, optional.
+        /// </summary>
+        /// <param name="json">The JSON array to create a Signer array from.</param>
+        /// <param name="addressVersion">The address version to use for the signers.</param>
+        /// <returns>A Signer array.</returns>
+        /// <exception cref="RpcException">Thrown when the JSON array is invalid or max allowed witness exceeded.</exception>
+        internal static Signer[] ToSigners(this JArray json, byte addressVersion)
+        {
+            if (json.Count > Transaction.MaxTransactionAttributes)
+                throw new RpcException(RpcError.InvalidParams.WithData("Max allowed witness exceeded."));
+
+            var ret = json.Select(u => new Signer
+            {
+                Account = u["account"].AsString().AddressToScriptHash(addressVersion),
+                Scopes = (WitnessScope)Enum.Parse(typeof(WitnessScope), u["scopes"]?.AsString()),
+                AllowedContracts = ((JArray)u["allowedcontracts"])?.Select(p => UInt160.Parse(p.AsString())).ToArray() ?? [],
+                AllowedGroups = ((JArray)u["allowedgroups"])?.Select(p => ECPoint.Parse(p.AsString(), ECCurve.Secp256r1)).ToArray() ?? [],
+                Rules = ((JArray)u["rules"])?.Select(r => WitnessRule.FromJson((JObject)r)).ToArray() ?? [],
+            }).ToArray();
+
+            // Validate format
+            _ = ret.ToByteArray().AsSerializableArray<Signer>();
+            return ret;
+        }
+
+        /// <summary>
+        /// Create a Witness array from a JSON array.   
+        /// Each item in the JSON array should be a JSON object with the following properties:
+        /// - "invocation": A base64-encoded string representing the invocation script, optional.
+        /// - "verification": A base64-encoded string representing the verification script, optional.
+        /// </summary>
+        /// <param name="json">The JSON array to create a Witness array from.</param>
+        /// <returns>A Witness array.</returns>
+        /// <exception cref="RpcException">Thrown when the JSON array is invalid or max allowed witness exceeded.</exception>
+        internal static Witness[] ToWitnesses(this JArray json)
+        {
+            if (json.Count > Transaction.MaxTransactionAttributes)
+                throw new RpcException(RpcError.InvalidParams.WithData("Max allowed witness exceeded."));
+
+            return json.Select(u => new
+            {
+                Invocation = u["invocation"]?.AsString(),
+                Verification = u["verification"]?.AsString()
+            })
+            .Where(x => x.Invocation != null || x.Verification != null)
+            .Select(x => new Witness()
+            {
+                InvocationScript = Convert.FromBase64String(x.Invocation ?? string.Empty),
+                VerificationScript = Convert.FromBase64String(x.Verification ?? string.Empty)
+            })
+            .ToArray();
+        }
+
+        /// <summary>
+        /// Converts an hex-encoded UInt160 or a Base58Check address to a script hash.
+        /// </summary>
+        /// <param name="address">The address to convert.</param>
+        /// <param name="version">The address version to use for the conversion.</param>
+        /// <returns>The script hash corresponding to the address.</returns>
+        internal static UInt160 AddressToScriptHash(this string address, byte version)
+        {
+            if (UInt160.TryParse(address, out var scriptHash))
+                return scriptHash;
+            return address.ToScriptHash(version);
+        }
     }
 
     public static class TypeExtensions

src/Plugins/RpcServer/RpcServer.SmartContract.cs

@@ -9,7 +9,6 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-using Neo.Cryptography.ECC;
 using Neo.Extensions;
 using Neo.Json;
 using Neo.Network.P2P.Payloads;
@@ -24,7 +23,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
-using Array = System.Array;
 
 namespace Neo.Plugins.RpcServer
 {
@@ -171,47 +169,6 @@ private static JObject ToJson(StackItem item, Session session)
             return json;
         }
 
-        private static Signer[] SignersFromJson(JArray _params, ProtocolSettings settings)
-        {
-            if (_params.Count > Transaction.MaxTransactionAttributes)
-            {
-                throw new RpcException(RpcError.InvalidParams.WithData("Max allowed witness exceeded."));
-            }
-
-            var ret = _params.Select(u => new Signer
-            {
-                Account = AddressToScriptHash(u["account"].AsString(), settings.AddressVersion),
-                Scopes = (WitnessScope)Enum.Parse(typeof(WitnessScope), u["scopes"]?.AsString()),
-                AllowedContracts = ((JArray)u["allowedcontracts"])?.Select(p => UInt160.Parse(p.AsString())).ToArray() ?? Array.Empty<UInt160>(),
-                AllowedGroups = ((JArray)u["allowedgroups"])?.Select(p => ECPoint.Parse(p.AsString(), ECCurve.Secp256r1)).ToArray() ?? Array.Empty<ECPoint>(),
-                Rules = ((JArray)u["rules"])?.Select(r => WitnessRule.FromJson((JObject)r)).ToArray() ?? Array.Empty<WitnessRule>(),
-            }).ToArray();
-
-            // Validate format
-
-            _ = ret.ToByteArray().AsSerializableArray<Signer>();
-
-            return ret;
-        }
-
-        private static Witness[] WitnessesFromJson(JArray _params)
-        {
-            if (_params.Count > Transaction.MaxTransactionAttributes)
-            {
-                throw new RpcException(RpcError.InvalidParams.WithData("Max allowed witness exceeded."));
-            }
-
-            return _params.Select(u => new
-            {
-                Invocation = u["invocation"]?.AsString(),
-                Verification = u["verification"]?.AsString()
-            }).Where(x => x.Invocation != null || x.Verification != null).Select(x => new Witness()
-            {
-                InvocationScript = Convert.FromBase64String(x.Invocation ?? string.Empty),
-                VerificationScript = Convert.FromBase64String(x.Verification ?? string.Empty)
-            }).ToArray();
-        }
-
         /// <summary>
         /// Invokes a function on a contract.
         /// <para>Request format:</para>
@@ -224,13 +181,16 @@ private static Witness[] WitnessesFromJson(JArray _params)
         ///     "operation",  // the operation to invoke
         ///     [{"type": "ContractParameterType", "value": "The parameter value"}],  // ContractParameter, the arguments
         ///     [{
-        ///       "account": "An UInt160 or Base58Check address",
-        ///       "scopes": "WitnessScope", // WitnessScope
+        ///       // The part of the Signer
+        ///       "account": "An UInt160 or Base58Check address", // The account of the signer, required
+        ///       "scopes": "WitnessScope", // WitnessScope, required
         ///       "allowedcontracts": ["The contract hash(UInt160)"], // optional
         ///       "allowedgroups": ["PublicKey"], // ECPoint, i.e. ECC PublicKey, optional
         ///       "rules": [{"action": "WitnessRuleAction", "condition": {/*A json of WitnessCondition*/}}] // WitnessRule
-        ///     }], // A Signer array, optional
-        ///     [{"invocation": "A Base64-encoded string","verification": "A Base64-encoded string"}] // A Witness array, optional
+        ///       // The part of the Witness, optional
+        ///       "invocation": "A Base64-encoded string",
+        ///       "verification": "A Base64-encoded string"
+        ///     }], // A JSON array of signers and witnesses, optional
         ///     false // useDiagnostic, a bool value indicating whether to use diagnostic information, optional
         ///   ]
         /// }</code>
@@ -266,9 +226,8 @@ private static Witness[] WitnessesFromJson(JArray _params)
         /// [0]: The script hash of the contract to invoke as a string.
         /// [1]: The operation to invoke as a string.
         /// [2]: The arguments to pass to the function as an array of ContractParameter. Optional.
-        /// [3]: The signers as an array of Signer. Optional.
-        /// [4]: The witnesses as an array of Witness. Optional.
-        /// [5]: A boolean value indicating whether to use diagnostic information. Optional.
+        /// [3]: The JSON array of signers and witnesses<see cref="ParameterConverter.ToSignersAndWitnesses"/>. Optional.
+        /// [4]: A boolean value indicating whether to use diagnostic information. Optional.
         /// </param>
         /// <returns>The result of the function invocation.</returns>
         /// <exception cref="RpcException">
@@ -277,17 +236,24 @@ private static Witness[] WitnessesFromJson(JArray _params)
         [RpcMethod]
         protected internal virtual JToken InvokeFunction(JArray _params)
         {
-            UInt160 script_hash = Result.Ok_Or(() => UInt160.Parse(_params[0].AsString()), RpcError.InvalidParams.WithData($"Invalid script hash {nameof(script_hash)}"));
-            string operation = Result.Ok_Or(() => _params[1].AsString(), RpcError.InvalidParams);
-            ContractParameter[] args = _params.Count >= 3 ? ((JArray)_params[2]).Select(p => ContractParameter.FromJson((JObject)p)).ToArray() : [];
-            Signer[] signers = _params.Count >= 4 ? SignersFromJson((JArray)_params[3], system.Settings) : null;
-            Witness[] witnesses = _params.Count >= 4 ? WitnessesFromJson((JArray)_params[3]) : null;
-            bool useDiagnostic = _params.Count >= 5 && _params[4].GetBoolean();
+            var scriptHash = Result.Ok_Or(() => UInt160.Parse(_params[0].AsString()),
+                RpcError.InvalidParams.WithData($"Invalid script hash `{_params[0]}`"));
+
+            var operation = Result.Ok_Or(() => _params[1].AsString(), RpcError.InvalidParams);
+            var args = _params.Count >= 3
+                ? ((JArray)_params[2]).Select(p => ContractParameter.FromJson((JObject)p)).ToArray()
+                : [];
+
+            var (signers, witnesses) = _params.Count >= 4
+                ? ((JArray)_params[3]).ToSignersAndWitnesses(system.Settings.AddressVersion)
+                : (null, null);
+
+            var useDiagnostic = _params.Count >= 5 && _params[4].GetBoolean();
 
             byte[] script;
             using (ScriptBuilder sb = new())
             {
-                script = sb.EmitDynamicCall(script_hash, operation, args).ToArray();
+                script = sb.EmitDynamicCall(scriptHash, operation, args).ToArray();
             }
             return GetInvokeResult(script, signers, witnesses, useDiagnostic);
         }
@@ -302,13 +268,16 @@ protected internal virtual JToken InvokeFunction(JArray _params)
         ///   "params": [
         ///     "A Base64-encoded script", // the script to invoke
         ///     [{
-        ///       "account": "An UInt160 or Base58Check address",
-        ///       "scopes": "WitnessScope", // WitnessScope
+        ///       // The part of the Signer
+        ///       "account": "An UInt160 or Base58Check address", // The account of the signer, required
+        ///       "scopes": "WitnessScope", // WitnessScope, required
         ///       "allowedcontracts": ["The contract hash(UInt160)"], // optional
         ///       "allowedgroups": ["PublicKey"], // ECPoint, i.e. ECC PublicKey, optional
-        ///       "rules": [{"action": "WitnessRuleAction", "condition": {A json of WitnessCondition}}] // WitnessRule
-        ///     }], // A Signer array, optional
-        ///     [{"invocation": "A Base64-encoded string","verification": "A Base64-encoded string"}] // A Witness array, optional
+        ///       "rules": [{"action": "WitnessRuleAction", "condition": {/* A json of WitnessCondition */ }}], // WitnessRule
+        ///       // The part of the Witness, optional
+        ///       "invocation": "A Base64-encoded string",
+        ///       "verification": "A Base64-encoded string"
+        ///     }], // A JSON array of signers and witnesses, optional
         ///     false // useDiagnostic, a bool value indicating whether to use diagnostic information, optional
         ///   ]
         /// }</code>
@@ -348,8 +317,7 @@ protected internal virtual JToken InvokeFunction(JArray _params)
         /// </summary>
         /// <param name="_params">An array containing the following elements:
         /// [0]: The script as a Base64-encoded string.
-        /// [1]: The signers as an array of Signer. Optional.
-        /// [2]: The witnesses as an array of Witness. Optional.
+        /// [1]: The JSON array of signers and witnesses<see cref="ParameterConverter.ToSignersAndWitnesses"/>. Optional.
         /// [3]: A boolean value indicating whether to use diagnostic information. Optional.
         /// </param>
         /// <returns>The result of the script invocation.</returns>
@@ -359,10 +327,11 @@ protected internal virtual JToken InvokeFunction(JArray _params)
         [RpcMethod]
         protected internal virtual JToken InvokeScript(JArray _params)
         {
-            byte[] script = Result.Ok_Or(() => Convert.FromBase64String(_params[0].AsString()), RpcError.InvalidParams);
-            Signer[] signers = _params.Count >= 2 ? SignersFromJson((JArray)_params[1], system.Settings) : null;
-            Witness[] witnesses = _params.Count >= 2 ? WitnessesFromJson((JArray)_params[1]) : null;
-            bool useDiagnostic = _params.Count >= 3 && _params[2].GetBoolean();
+            var script = Result.Ok_Or(() => Convert.FromBase64String(_params[0].AsString()), RpcError.InvalidParams);
+            var (signers, witnesses) = _params.Count >= 2
+                ? ((JArray)_params[1]).ToSignersAndWitnesses(system.Settings.AddressVersion)
+                : (null, null);
+            var useDiagnostic = _params.Count >= 3 && _params[2].GetBoolean();
             return GetInvokeResult(script, signers, witnesses, useDiagnostic);
         }
 
@@ -469,9 +438,12 @@ protected internal virtual JToken TerminateSession(JArray _params)
         [RpcMethod]
         protected internal virtual JToken GetUnclaimedGas(JArray _params)
         {
-            string address = Result.Ok_Or(() => _params[0].AsString(), RpcError.InvalidParams.WithData($"Invalid address {nameof(address)}"));
+            var address = Result.Ok_Or(() => _params[0].AsString(),
+                RpcError.InvalidParams.WithData($"Invalid address `{_params[0]}`"));
             var json = new JObject();
-            UInt160 scriptHash = Result.Ok_Or(() => AddressToScriptHash(address, system.Settings.AddressVersion), RpcError.InvalidParams);
+            var scriptHash = Result.Ok_Or(
+                () => address.AddressToScriptHash(system.Settings.AddressVersion),
+                RpcError.InvalidParams.WithData($"Invalid address `{address}`"));
 
             var snapshot = system.StoreView;
             json["unclaimed"] = NativeContract.NEO.UnclaimedGas(snapshot, scriptHash, NativeContract.Ledger.CurrentIndex(snapshot) + 1).ToString();