Merge pull request #19 from dbolin/nullablePerf

improve performance of nullables

Apex.Serialization/Internal/DynamicCode.cs

@@ -275,6 +275,13 @@ private static Expression WriteValue(ParameterExpression stream, ParameterExpres
                 return primitiveExpression;
             }
 
+            var nullableExpression = HandleNullableWrite(stream, output, declaredType, settings, visitedTypes, valueAccessExpression);
+            if (nullableExpression != null)
+            {
+                inlineWrite = true;
+                return nullableExpression;
+            }
+
             var customExpression = HandleCustomWrite(output, declaredType, valueAccessExpression, settings);
             if (customExpression != null)
             {
@@ -331,6 +338,36 @@ private static Expression WriteValue(ParameterExpression stream, ParameterExpres
             }
         }
 
+        private static Expression? HandleNullableWrite(ParameterExpression stream, ParameterExpression output,
+            Type declaredType, ImmutableSettings settings, ImmutableHashSet<Type> visitedTypes,
+            Expression valueAccessExpression)
+        {
+            if (!declaredType.IsGenericType || declaredType.GetGenericTypeDefinition() != typeof(Nullable<>))
+            {
+                return null;
+            }
+
+            var hasValueMethod = declaredType.GetProperty("HasValue")!.GetGetMethod()!;
+            var valueMethod = declaredType.GetProperty("Value")!.GetGetMethod()!;
+            var nullableType = declaredType.GenericTypeArguments[0];
+            var isPrimitive = TypeFields.IsPrimitive(nullableType);
+
+            return Expression.IfThenElse(
+                Expression.Call(valueAccessExpression, hasValueMethod),
+                Expression.Block(
+                    new[] {
+                        !isPrimitive ? (Expression)Expression.Call(stream, BinaryStreamMethods<TStream>.ReserveSizeMethodInfo, Expression.Constant(1)) : Expression.Empty(),
+                        Expression.Call(stream, BinaryStreamMethods<TStream>.GenericMethods<byte>.WriteValueMethodInfo, Expression.Constant((byte)1)),
+                    }
+                        .Concat(
+                    GetWriteStatementsForType(nullableType, settings, stream, output,
+                        Expression.Call(valueAccessExpression, valueMethod), false, Expression.Call(valueAccessExpression, valueMethod),
+                        visitedTypes, writeSize: !isPrimitive))
+                    ),
+                Expression.Call(stream, BinaryStreamMethods<TStream>.GenericMethods<byte>.WriteValueMethodInfo, Expression.Constant((byte)0))
+                );
+        }
+
         private static Expression? HandleCustomWrite(ParameterExpression output, Type declaredType,
             Expression valueAccessExpression, ImmutableSettings settings)
         {
@@ -437,7 +474,7 @@ internal static T GenerateReadMethodImpl<T>(Type type, ImmutableSettings setting
         }
 
         private static List<Expression> GetReadStatementsForType(Type type, ImmutableSettings settings, ParameterExpression stream,
-            ParameterExpression output, Expression result,List<ParameterExpression> localVariables,
+            ParameterExpression output, Expression result, List<ParameterExpression> localVariables,
             ImmutableHashSet<Type> visitedTypes, bool readMetadata = false,
             bool reserveNeededSize = true)
         {
@@ -903,6 +940,13 @@ private static Expression ReadValue(ParameterExpression stream, ParameterExpress
                 return primitiveExpression;
             }
 
+            var nullableExpression = HandleNullableRead(stream, output, declaredType, settings, localVariables, visitedTypes);
+            if (nullableExpression != null)
+            {
+                isInlineRead = true;
+                return nullableExpression;
+            }
+
             var readStructExpression = ReadStructExpression(declaredType, stream, TypeFields.GetOrderedFields(declaredType));
             if (readStructExpression != null)
             {
@@ -971,5 +1015,33 @@ private static Expression ReadValue(ParameterExpression stream, ParameterExpress
 
             return null;
         }
+
+        private static Expression? HandleNullableRead(ParameterExpression stream, ParameterExpression output, Type declaredType,
+            ImmutableSettings settings, List<ParameterExpression> localVariables, ImmutableHashSet<Type> visitedTypes)
+        {
+            if (!declaredType.IsGenericType || declaredType.GetGenericTypeDefinition() != typeof(Nullable<>))
+            {
+                return null;
+            }
+
+            var nullableType = declaredType.GenericTypeArguments[0];
+            var isPrimitive = TypeFields.IsPrimitive(nullableType);
+            var tempResult = Expression.Variable(nullableType, "tempResult");
+
+            return 
+                Expression.Block(
+                    !isPrimitive ? (Expression)Expression.Call(stream, BinaryStreamMethods<TStream>.ReserveSizeMethodInfo, Expression.Constant(1)) : Expression.Empty(),
+                    Expression.Condition(
+                        Expression.Equal(Expression.Call(stream, BinaryStreamMethods<TStream>.GenericMethods<byte>.ReadValueMethodInfo), Expression.Constant((byte)0)),
+                        Expression.Default(declaredType),
+                        Expression.Convert(
+                            Expression.Block(new[] { tempResult },
+                                GetReadStatementsForType(nullableType, settings, stream, output, tempResult, localVariables,
+                                    visitedTypes, reserveNeededSize: !isPrimitive)
+                                .Concat(new[] { tempResult })),
+                            declaredType)
+                        )
+                    );
+        }
     }
 }

Apex.Serialization/Internal/Reflection/TypeFields.cs

@@ -99,6 +99,19 @@ private static bool TryGetSizeForStruct(Type type, out int sizeForField)
             var fields = GetFields(type);
             int size;
 
+            if (type.IsGenericType && typeof(Nullable<>) == type.GetGenericTypeDefinition())
+            {
+                var (innerSize, isRef) = GetSizeForType(type.GenericTypeArguments[0]);
+                if(isRef)
+                {
+                    sizeForField = 5;
+                    return false;
+                }
+
+                sizeForField = innerSize + Unsafe.SizeOf<byte>();
+                return true;
+            }
+
             if (type.IsValueType && fields.All(f => IsPrimitive(f.FieldType)))
             {
                 if(fields.Count == 0)

Benchmark/PerformanceSuite_NullableInts.cs

@@ -0,0 +1,31 @@
+using BenchmarkDotNet.Attributes;
+using System.Collections.Generic;
+using System.Linq;
+
+#nullable disable
+
+namespace Benchmark
+{
+    public class PerformanceSuite_NullableInts : PerformanceSuiteBase
+    {
+        private readonly List<int?> _listInt = new List<int?>(Enumerable.Range(0, 1024).Select(x => (int?)x));
+
+        public PerformanceSuite_NullableInts()
+        {
+            _listInt.Capacity = 1024;
+            S_NullableInts();
+        }
+
+        [Benchmark]
+        public void S_NullableInts()
+        {
+            Serialize(_listInt);
+        }
+
+        [Benchmark]
+        public object D_NullableInts()
+        {
+            return Deserialize<List<int?>>();
+        }
+    }
+}

Benchmark/PerformanceSuite_Nullables.cs → Benchmark/PerformanceSuite_NullableWrappedStruct.cs

@@ -8,7 +8,7 @@
 
 namespace Benchmark
 {
-    public class PerformanceSuite_Nullables : PerformanceSuiteBase
+    public class PerformanceSuite_NullableWrappedStruct : PerformanceSuiteBase
     {
         [StructLayout(LayoutKind.Explicit)]
         public struct Struct1
@@ -24,21 +24,22 @@ public class Wrapper
             public Struct1? NullableField;
         }
 
-        private readonly List<Wrapper> _emptyListFull = new List<Wrapper>(Enumerable.Range(0, 1024).Select(x => new Wrapper()));
-        public PerformanceSuite_Nullables()
+        private readonly List<Wrapper> _listWrapper = new List<Wrapper>(Enumerable.Range(0, 1024).Select(x => new Wrapper()));
+
+        public PerformanceSuite_NullableWrappedStruct()
         {
-            _emptyListFull.Capacity = 1024;
-            S_Nullables();
+            _listWrapper.Capacity = 1024;
+            S_NullableWrapper();
         }
 
         [Benchmark]
-        public void S_Nullables()
+        public void S_NullableWrapper()
         {
-            Serialize(_emptyListFull);
+            Serialize(_listWrapper);
         }
 
         [Benchmark]
-        public object D_Nullables()
+        public object D_NullableWrapper()
         {
             return Deserialize<List<Wrapper>>();
         }

BenchmarkCases/PerformanceSuite.md

@@ -43,8 +43,12 @@ Internal benchmarks
 | S_SortedDictionaryOfValues | 1.351 us | 0.0048 us | 0.0045 us |      - |     - |     - |         - |
 | D_SortedDictionaryOfValues | 9.416 us | 0.1115 us | 0.0989 us | 0.4425 |     - |     - |    4936 B |
 
-|      Method |      Mean |     Error |    StdDev |  Gen 0 | Gen 1 | Gen 2 | Allocated |
-|------------ |----------:|----------:|----------:|-------:|------:|------:|----------:|
-| S_Nullables |  6.177 us | 0.0572 us | 0.0535 us |      - |     - |     - |         - |
-| D_Nullables | 15.901 us | 0.1371 us | 0.1282 us | 3.9673 |     - |     - |   49208 B |
-
+|         Method |     Mean |     Error |    StdDev |  Gen 0 | Gen 1 | Gen 2 | Allocated |
+|--------------- |---------:|----------:|----------:|-------:|------:|------:|----------:|
+| S_NullableInts | 3.582 us | 0.0100 us | 0.0093 us |      - |     - |     - |         - |
+| D_NullableInts | 5.318 us | 0.1031 us | 0.1227 us | 0.6638 |     - |     - |    8248 B |
+
+|            Method |      Mean |     Error |    StdDev |  Gen 0 | Gen 1 | Gen 2 | Allocated |
+|------------------ |----------:|----------:|----------:|-------:|------:|------:|----------:|
+| S_NullableWrapper |  3.540 us | 0.0141 us | 0.0125 us |      - |     - |     - |         - |
+| D_NullableWrapper | 10.697 us | 0.0948 us | 0.0886 us | 3.9978 |     - |     - |   49208 B |

Tests/Apex.Serialization.Tests/ArrayTests.cs

@@ -1,6 +1,7 @@
 using FluentAssertions;
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Numerics;
 using System.Runtime.InteropServices;
@@ -209,6 +210,30 @@ public void NullableDecimalArray()
             RoundTrip(x);
         }
 
+        public sealed class TestObject1
+        {
+            public decimal O { get; }
+            public string? Im { get; }
+            public string? T { get; }
+            public string? In { get; }
+            public ImmutableArray<CustomProperty>? Cu { get; }
+
+            public TestObject1(
+                ImmutableArray<CustomProperty>? cu)
+            {
+                Cu = cu;
+            }
+        }
+
+        [Fact]
+        public void NestedNullable()
+        {
+            var a = Enumerable.Range(0, 100).Select(x => new CustomProperty("", new Value { _string = "" })).ToImmutableArray();
+            var x = new TestObject1(a);
+
+            RoundTrip(x, (a,b) => true);
+        }
+
         [Fact]
         public void NullArrays()
         {

Tests/Apex.Serialization.Tests/Collections/Objects/RandomHashcode.cs

@@ -23,15 +23,13 @@ public override int GetHashCode()
         public static bool operator ==(RandomHashcode hashcode1, RandomHashcode hashcode2) => hashcode1.Equals(hashcode2);
         public static bool operator !=(RandomHashcode hashcode1, RandomHashcode hashcode2) => !(hashcode1 == hashcode2);
 
-        private static Random _random = new Random();
-
         internal static void NewRandomizer()
         {
             var old = HashCodeRandomizer;
 
             while (HashCodeRandomizer == old)
             {
-                HashCodeRandomizer = _random.Next();
+                HashCodeRandomizer = HashCodeRandomizer * 37 + 19999;
             }
         }