Optimize ECPoint serialization (#3757)

* Optimize PubKey

* Rename to ISerializableSpan

* @nan01ab feedback

* clean using

src/Neo.IO/ISerializableSpan.cs

@@ -0,0 +1,32 @@
+// Copyright (C) 2015-2025 The Neo Project.
+//
+// ISerializableSpan.cs file belongs to the neo project and is free
+// software distributed under the MIT software license, see the
+// accompanying file LICENSE in the main directory of the
+// repository or http://www.opensource.org/licenses/mit-license.php
+// for more details.
+//
+// Redistribution and use in source and binary forms with or without
+// modifications are permitted.
+
+using System;
+
+namespace Neo.IO
+{
+    /// <summary>
+    /// Represents NEO objects that can be serialized.
+    /// </summary>
+    public interface ISerializableSpan
+    {
+        /// <summary>
+        /// The size of the object in bytes after serialization.
+        /// </summary>
+        int Size { get; }
+
+        /// <summary>
+        /// Gets a ReadOnlySpan that represents the current value
+        /// Requires keeping the data returned by GetSpan consistent with the data generated by <see cref="ISerializable"/>.
+        /// </summary>
+        ReadOnlySpan<byte> GetSpan();
+    }
+}

src/Neo/Cryptography/ECC/ECPoint.cs

@@ -15,13 +15,14 @@
 using System;
 using System.IO;
 using System.Numerics;
+using System.Runtime.CompilerServices;
 
 namespace Neo.Cryptography.ECC
 {
     /// <summary>
     /// Represents a (X,Y) coordinate pair for elliptic curve cryptography (ECC) structures.
     /// </summary>
-    public class ECPoint : IComparable<ECPoint>, IEquatable<ECPoint>, ISerializable
+    public class ECPoint : IComparable<ECPoint>, IEquatable<ECPoint>, ISerializable, ISerializableSpan
     {
         internal ECFieldElement X, Y;
         internal readonly ECCurve Curve;
@@ -187,10 +188,10 @@ public byte[] EncodePoint(bool commpressed)
             {
                 if (_uncompressedPoint != null) return _uncompressedPoint;
                 data = new byte[65];
-                byte[] yBytes = Y.Value.ToByteArray(isUnsigned: true, isBigEndian: true);
+                var yBytes = Y.Value.ToByteArray(isUnsigned: true, isBigEndian: true);
                 Buffer.BlockCopy(yBytes, 0, data, 65 - yBytes.Length, yBytes.Length);
             }
-            byte[] xBytes = X.Value.ToByteArray(isUnsigned: true, isBigEndian: true);
+            var xBytes = X.Value.ToByteArray(isUnsigned: true, isBigEndian: true);
             Buffer.BlockCopy(xBytes, 0, data, 33 - xBytes.Length, xBytes.Length);
             data[0] = commpressed ? Y.Value.IsEven ? (byte)0x02 : (byte)0x03 : (byte)0x04;
             if (commpressed) _compressedPoint = data;
@@ -350,6 +351,16 @@ void ISerializable.Serialize(BinaryWriter writer)
             writer.Write(EncodePoint(true));
         }
 
+        /// <summary>
+        /// Gets a ReadOnlySpan that represents the current value.
+        /// </summary>
+        /// <returns>A ReadOnlySpan that represents the current value.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public ReadOnlySpan<byte> GetSpan()
+        {
+            return EncodePoint(true).AsSpan();
+        }
+
         public override string ToString()
         {
             return EncodePoint(true).ToHexString();

src/Neo/SmartContract/KeyBuilder.cs

@@ -74,36 +74,12 @@ public KeyBuilder Add(ReadOnlySpan<byte> key)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public KeyBuilder Add(byte[] key) => Add(key.AsSpan());
 
-        /// <summary>
-        /// Adds part of the key to the builder.
-        /// </summary>
-        /// <param name="key">Part of the key represented by a <see cref="UInt160"/>.</param>
-        /// <returns>A reference to this instance after the add operation has completed.</returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public KeyBuilder Add(UInt160 key) => Add(key.GetSpan());
-
-        /// <summary>
-        /// Adds part of the key to the builder.
-        /// </summary>
-        /// <param name="key">Part of the key represented by a <see cref="UInt256"/>.</param>
-        /// <returns>A reference to this instance after the add operation has completed.</returns>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public KeyBuilder Add(UInt256 key) => Add(key.GetSpan());
-
         /// <summary>
         /// Adds part of the key to the builder.
         /// </summary>
         /// <param name="key">Part of the key.</param>
         /// <returns>A reference to this instance after the add operation has completed.</returns>
-        public KeyBuilder Add(ISerializable key)
-        {
-            using (BinaryWriter writer = new(_stream, Utility.StrictUTF8, true))
-            {
-                key.Serialize(writer);
-                writer.Flush();
-            }
-            return this;
-        }
+        public KeyBuilder Add(ISerializableSpan key) => Add(key.GetSpan());
 
         /// <summary>
         /// Adds part of the key to the builder in BigEndian.

src/Neo/UInt160.cs

@@ -22,7 +22,7 @@ namespace Neo
     /// Represents a 160-bit unsigned integer.
     /// </summary>
     [StructLayout(LayoutKind.Explicit, Size = 20)]
-    public class UInt160 : IComparable<UInt160>, IEquatable<UInt160>, ISerializable
+    public class UInt160 : IComparable<UInt160>, IEquatable<UInt160>, ISerializable, ISerializableSpan
     {
         /// <summary>
         /// The length of <see cref="UInt160"/> values.

src/Neo/UInt256.cs

@@ -22,7 +22,7 @@ namespace Neo
     /// Represents a 256-bit unsigned integer.
     /// </summary>
     [StructLayout(LayoutKind.Explicit, Size = 32)]
-    public class UInt256 : IComparable<UInt256>, IEquatable<UInt256>, ISerializable
+    public class UInt256 : IComparable<UInt256>, IEquatable<UInt256>, ISerializable, ISerializableSpan
     {
         /// <summary>
         /// The length of <see cref="UInt256"/> values.

tests/Neo.Plugins.OracleService.Tests/TestUtils.cs

@@ -30,7 +30,7 @@ public static class TestUtils
         public static readonly UInt160 MultisigScriptHash = MultisigScript.ToScriptHash();
         public static readonly string MultisigAddress = MultisigScriptHash.ToAddress(ProtocolSettings.Default.AddressVersion);
 
-        public static StorageKey CreateStorageKey(this NativeContract contract, byte prefix, ISerializable key)
+        public static StorageKey CreateStorageKey(this NativeContract contract, byte prefix, ISerializableSpan key)
         {
             var k = new KeyBuilder(contract.Id, prefix);
             if (key != null) k = k.Add(key);

tests/Neo.UnitTests/Cryptography/ECC/UT_ECPoint.cs

@@ -171,7 +171,7 @@ public void TestEncodePoint()
         [TestMethod]
         public void TestEquals()
         {
-            ECPoint point = ECCurve.Secp256k1.G;
+            var point = ECCurve.Secp256k1.G;
             Assert.IsTrue(point.Equals(point));
             Assert.IsFalse(point.Equals(null));
 
@@ -309,11 +309,15 @@ public void TestDeserialize()
         [TestMethod]
         public void TestSerialize()
         {
-            MemoryStream stream = new MemoryStream();
-            ECPoint point = new ECPoint(null, null, ECCurve.Secp256k1);
+            var stream = new MemoryStream();
+            var point = new ECPoint(null, null, ECCurve.Secp256k1);
             ISerializable serializable = point;
             serializable.Serialize(new BinaryWriter(stream));
             CollectionAssert.AreEqual(new byte[] { 0 }, stream.ToArray());
+
+            CollectionAssert.AreEqual(point.GetSpan().ToArray(), stream.ToArray());
+            point = ECCurve.Secp256r1.G;
+            CollectionAssert.AreEqual(point.GetSpan().ToArray(), point.ToArray());
         }
 
         [TestMethod]

tests/Neo.UnitTests/SmartContract/UT_KeyBuilder.cs

@@ -27,11 +27,11 @@ public void Test()
             Assert.AreEqual("0100000002", key.ToArray().ToHexString());
 
             key = new KeyBuilder(1, 2);
-            key = key.Add(new byte[] { 3, 4 });
+            key = key.Add([3, 4]);
             Assert.AreEqual("01000000020304", key.ToArray().ToHexString());
 
             key = new KeyBuilder(1, 2);
-            key = key.Add(new byte[] { 3, 4 });
+            key = key.Add([3, 4]);
             key = key.Add(UInt160.Zero);
             Assert.AreEqual("010000000203040000000000000000000000000000000000000000", key.ToArray().ToHexString());
 
@@ -91,7 +91,7 @@ public void TestAddUInt()
             Assert.AreEqual("0100000002000102030405060708090a0b0c0d0e0f10111213", key.ToArray().ToHexString());
 
             var key2 = new KeyBuilder(1, 2);
-            key2 = key2.Add((ISerializable)(new UInt160(value)));
+            key2 = key2.Add((ISerializableSpan)new UInt160(value));
 
             // It must be same before and after optimization.
             Assert.AreEqual(key.ToArray().ToHexString(), key2.ToArray().ToHexString());
@@ -104,7 +104,7 @@ public void TestAddUInt()
             Assert.AreEqual("0100000002000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", key.ToArray().ToHexString());
 
             key2 = new KeyBuilder(1, 2);
-            key2 = key2.Add((ISerializable)(new UInt256(value)));
+            key2 = key2.Add((ISerializableSpan)new UInt256(value));
 
             // It must be same before and after optimization.
             Assert.AreEqual(key.ToArray().ToHexString(), key2.ToArray().ToHexString());

tests/Neo.UnitTests/TestUtils.cs

@@ -24,23 +24,23 @@ namespace Neo.UnitTests
 {
     public static partial class TestUtils
     {
-        public static readonly Random TestRandom = new Random(1337); // use fixed seed for guaranteed determinism
+        public static readonly Random TestRandom = new(1337); // use fixed seed for guaranteed determinism
 
         public static UInt256 RandomUInt256()
         {
-            byte[] data = new byte[32];
+            var data = new byte[32];
             TestRandom.NextBytes(data);
             return new UInt256(data);
         }
 
         public static UInt160 RandomUInt160()
         {
-            byte[] data = new byte[20];
+            var data = new byte[20];
             TestRandom.NextBytes(data);
             return new UInt160(data);
         }
 
-        public static StorageKey CreateStorageKey(this NativeContract contract, byte prefix, ISerializable key = null)
+        public static StorageKey CreateStorageKey(this NativeContract contract, byte prefix, ISerializableSpan key = null)
         {
             var k = new KeyBuilder(contract.Id, prefix);
             if (key != null) k = k.Add(key);
@@ -54,9 +54,9 @@ public static StorageKey CreateStorageKey(this NativeContract contract, byte pre
 
         public static byte[] GetByteArray(int length, byte firstByte)
         {
-            byte[] array = new byte[length];
+            var array = new byte[length];
             array[0] = firstByte;
-            for (int i = 1; i < length; i++)
+            for (var i = 1; i < length; i++)
             {
                 array[i] = 0x20;
             }
@@ -65,7 +65,7 @@ public static byte[] GetByteArray(int length, byte firstByte)
 
         public static NEP6Wallet GenerateTestWallet(string password)
         {
-            JObject wallet = new JObject();
+            var wallet = new JObject();
             wallet["name"] = "noname";
             wallet["version"] = new Version("1.0").ToString();
             wallet["scrypt"] = new ScryptParameters(2, 1, 1).ToJson();
@@ -103,7 +103,7 @@ public static void StorageItemAdd(DataCache snapshot, int id, byte[] keyValue, b
 
         public static void FillMemoryPool(DataCache snapshot, NeoSystem system, NEP6Wallet wallet, WalletAccount account)
         {
-            for (int i = 0; i < system.Settings.MemoryPoolMaxTransactions; i++)
+            for (var i = 0; i < system.Settings.MemoryPoolMaxTransactions; i++)
             {
                 var tx = CreateValidTx(snapshot, wallet, account);
                 system.MemPool.TryAdd(tx, snapshot);