Small performance improvements (#1636)

* change IReflectionService to return reusable fun to generate enum values via GetEnumValueConverter
* fix inheritdoc typo
* use string interpolation and less LINQ in JsonReferenceVisitorBase

src/NJsonSchema.NewtonsoftJson/Generation/NewtonsoftJsonReflectionService.cs

@@ -15,16 +15,14 @@
 using NJsonSchema.Infrastructure;
 using System.Runtime.Serialization;
 using System.Reflection;
-using NJsonSchema;
 using NJsonSchema.Generation;
-using System.Collections.Generic;
 
 namespace NJsonSchema.NewtonsoftJson.Generation
 {
-    /// <inheritdocs />
+    /// <inheritdoc />
     public class NewtonsoftJsonReflectionService : ReflectionServiceBase<NewtonsoftJsonSchemaGeneratorSettings>
     {
-        /// <inheritdocs />
+        /// <inheritdoc />
         protected override JsonTypeDescription GetDescription(ContextualType contextualType, NewtonsoftJsonSchemaGeneratorSettings settings,
             Type originalType, bool isNullable, ReferenceTypeNullHandling defaultReferenceTypeNullHandling)
         {
@@ -38,7 +36,7 @@ public class NewtonsoftJsonReflectionService : ReflectionServiceBase<NewtonsoftJ
             return base.GetDescription(contextualType, settings, originalType, isNullable, defaultReferenceTypeNullHandling);
         }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override bool IsNullable(ContextualType contextualType, ReferenceTypeNullHandling defaultReferenceTypeNullHandling)
         {
             var jsonPropertyAttribute = contextualType.GetContextAttribute<JsonPropertyAttribute>();
@@ -50,28 +48,27 @@ public override bool IsNullable(ContextualType contextualType, ReferenceTypeNull
             return base.IsNullable(contextualType, defaultReferenceTypeNullHandling);
         }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override bool IsStringEnum(ContextualType contextualType, NewtonsoftJsonSchemaGeneratorSettings settings)
         {
             var hasGlobalStringEnumConverter = settings.SerializerSettings?.Converters.OfType<StringEnumConverter>().Any() == true;
             return hasGlobalStringEnumConverter || base.IsStringEnum(contextualType, settings);
         }
 
-        /// <inheritdocs />
-        public override string ConvertEnumValue(object value, NewtonsoftJsonSchemaGeneratorSettings settings)
+
+        /// <inheritdoc />
+        public override Func<object, string?> GetEnumValueConverter(NewtonsoftJsonSchemaGeneratorSettings settings)
         {
-            var converters = settings.SerializerSettings?.Converters.ToList() ?? new List<JsonConverter>();
+            var converters = settings.SerializerSettings.Converters.ToList();
             if (!converters.OfType<StringEnumConverter>().Any())
             {
                 converters.Add(new StringEnumConverter());
             }
 
-            var json = JsonConvert.SerializeObject(value, Formatting.None, converters.ToArray());
-            var enumString = JsonConvert.DeserializeObject<string>(json)!;
-            return enumString;
+            return x => JsonConvert.DeserializeObject<string?>(JsonConvert.SerializeObject(x, Formatting.None, converters.ToArray()));
         }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override void GenerateProperties(JsonSchema schema, ContextualType contextualType, NewtonsoftJsonSchemaGeneratorSettings settings, JsonSchemaGenerator schemaGenerator, JsonSchemaResolver schemaResolver)
         {
             var contextualAccessors = contextualType
@@ -150,7 +147,7 @@ public override void GenerateProperties(JsonSchema schema, ContextualType contex
             }
         }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override string GetPropertyName(ContextualAccessorInfo accessorInfo, JsonSchemaGeneratorSettings settings)
         {
             return GetPropertyName(null, accessorInfo, (NewtonsoftJsonSchemaGeneratorSettings)settings);
@@ -197,7 +194,7 @@ private void LoadPropertyOrField(JsonProperty jsonProperty, ContextualAccessorIn
             }
         }
 
-        private string GetPropertyName(JsonProperty? jsonProperty, ContextualAccessorInfo accessorInfo, NewtonsoftJsonSchemaGeneratorSettings settings)
+        private static string GetPropertyName(JsonProperty? jsonProperty, ContextualAccessorInfo accessorInfo, NewtonsoftJsonSchemaGeneratorSettings settings)
         {
             if (jsonProperty?.PropertyName != null)
             {
@@ -208,8 +205,7 @@ private string GetPropertyName(JsonProperty? jsonProperty, ContextualAccessorInf
             {
                 var propertyName = accessorInfo.GetName();
 
-                var contractResolver = settings.ActualContractResolver as DefaultContractResolver;
-                return contractResolver != null
+                return settings.ActualContractResolver is DefaultContractResolver contractResolver
                     ? contractResolver.GetResolvedPropertyName(propertyName)
                     : propertyName;
             }

src/NJsonSchema.NewtonsoftJson/Generation/NewtonsoftJsonSchemaGeneratorSettings.cs

@@ -15,7 +15,7 @@
 
 namespace NJsonSchema.NewtonsoftJson.Generation
 {
-    /// <inheritdocs />
+    /// <inheritdoc />
     public class NewtonsoftJsonSchemaGeneratorSettings : JsonSchemaGeneratorSettings
     {
         private Dictionary<string, JsonContract?> _cachedContracts = new Dictionary<string, JsonContract?>();

src/NJsonSchema/Annotations/JsonSchemaExtensionDataAttribute.cs

@@ -33,7 +33,7 @@ public JsonSchemaExtensionDataAttribute(string key, object value)
         /// <summary>Gets the value.</summary>
         public object Value { get; }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public IReadOnlyDictionary<string, object> ExtensionData => new Dictionary<string, object>
         {
             { Key, Value }

src/NJsonSchema/Generation/IReflectionService.cs

@@ -15,12 +15,11 @@ namespace NJsonSchema.Generation
     public interface IReflectionService
     {
         /// <summary>
-        /// Converts an enum value to a JSON string.
+        /// Get converter that converts an enum value to a JSON string.
         /// </summary>
-        /// <param name="value"></param>
         /// <param name="settings"></param>
         /// <returns></returns>
-        string ConvertEnumValue(object value, JsonSchemaGeneratorSettings settings);
+        Func<object, string?> GetEnumValueConverter(JsonSchemaGeneratorSettings settings);
 
         /// <summary>
         /// Gets the property name for the given accessor info.

src/NJsonSchema/Generation/JsonSchemaGenerator.cs

@@ -18,6 +18,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.Serialization;
 
 namespace NJsonSchema.Generation
 {
@@ -700,6 +701,7 @@ protected virtual void GenerateEnum(JsonSchema schema, JsonTypeDescription typeD
             schema.EnumerationNames.Clear();
             schema.IsFlagEnumerable = contextualType.GetInheritedAttribute<FlagsAttribute>() != null;
 
+            Func<object, string?>? enumValueConverter = null;
             var underlyingType = Enum.GetUnderlyingType(contextualType.Type);
             foreach (var enumName in Enum.GetNames(contextualType.Type))
             {
@@ -711,16 +713,16 @@ protected virtual void GenerateEnum(JsonSchema schema, JsonTypeDescription typeD
                 else
                 {
                     // EnumMember only checked if StringEnumConverter is used
-                    var attributes = contextualType.Type.GetRuntimeField(enumName)?.GetCustomAttributes();
-                    dynamic? enumMemberAttribute = attributes?.FirstAssignableToTypeNameOrDefault("System.Runtime.Serialization.EnumMemberAttribute");
-                    if (!string.IsNullOrEmpty(enumMemberAttribute?.Value))
+                    var enumMemberAttribute = contextualType.Type.GetRuntimeField(enumName)?.GetCustomAttribute<EnumMemberAttribute>();
+                    if (enumMemberAttribute != null && !string.IsNullOrEmpty(enumMemberAttribute.Value))
                     {
-                        schema.Enumeration.Add((string)enumMemberAttribute!.Value);
+                        schema.Enumeration.Add(enumMemberAttribute.Value);
                     }
                     else
                     {
+                        enumValueConverter ??= Settings.ReflectionService.GetEnumValueConverter(Settings);
                         var value = Enum.Parse(contextualType.Type, enumName);
-                        schema.Enumeration.Add(Settings.ReflectionService.ConvertEnumValue(value, Settings));
+                        schema.Enumeration.Add(enumValueConverter(value));
                     }
                 }
 

src/NJsonSchema/Generation/ReflectionServiceBase.cs

@@ -19,13 +19,13 @@ namespace NJsonSchema.Generation
     public abstract class ReflectionServiceBase<TSettings> : IReflectionService
         where TSettings : JsonSchemaGeneratorSettings
     {
-        /// <inheritdocs />
-        public abstract string ConvertEnumValue(object value, TSettings settings);
+        /// <inheritdoc />
+        public abstract Func<object, string?> GetEnumValueConverter(TSettings settings);
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public abstract void GenerateProperties(JsonSchema schema, ContextualType contextualType, TSettings settings, JsonSchemaGenerator schemaGenerator, JsonSchemaResolver schemaResolver);
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public abstract string GetPropertyName(ContextualAccessorInfo accessorInfo, JsonSchemaGeneratorSettings settings);
 
         /// <summary>Creates a <see cref="JsonTypeDescription"/> from a <see cref="Type"/>. </summary>
@@ -368,9 +368,9 @@ bool IReflectionService.IsStringEnum(ContextualType contextualType, JsonSchemaGe
             return IsStringEnum(contextualType, (TSettings)settings);
         }
 
-        string IReflectionService.ConvertEnumValue(object value, JsonSchemaGeneratorSettings settings)
+        Func<object, string?> IReflectionService.GetEnumValueConverter(JsonSchemaGeneratorSettings settings)
         {
-            return ConvertEnumValue(value, (TSettings)settings);
+            return GetEnumValueConverter((TSettings)settings);
         }
 
         void IReflectionService.GenerateProperties(JsonSchema schema, ContextualType contextualType, JsonSchemaGeneratorSettings settings, JsonSchemaGenerator schemaGenerator, JsonSchemaResolver schemaResolver)

src/NJsonSchema/Generation/SystemTextJsonReflectionService.cs

@@ -17,20 +17,16 @@
 
 namespace NJsonSchema.Generation
 {
-    /// <inheritdocs />
+    /// <inheritdoc />
     public class SystemTextJsonReflectionService : ReflectionServiceBase<SystemTextJsonSchemaGeneratorSettings>
     {
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override void GenerateProperties(JsonSchema schema, ContextualType contextualType, SystemTextJsonSchemaGeneratorSettings settings, JsonSchemaGenerator schemaGenerator, JsonSchemaResolver schemaResolver)
         {
-            foreach (var accessorInfo in contextualType
-                .Properties
-                .OfType<ContextualAccessorInfo>()
-                .Concat(contextualType.Fields)
-                .Where(p => p.MemberInfo.DeclaringType == contextualType.Type))
+            foreach (var accessorInfo in contextualType.Properties.OfType<ContextualAccessorInfo>().Concat(contextualType.Fields))
             {
-                if (accessorInfo.MemberInfo is FieldInfo fieldInfo &&
-                    (fieldInfo.IsPrivate || fieldInfo.IsStatic || !fieldInfo.IsDefined(typeof(DataMemberAttribute))))
+                if (accessorInfo.MemberInfo.DeclaringType != contextualType.Type ||
+                    (accessorInfo.MemberInfo is FieldInfo fieldInfo && (fieldInfo.IsPrivate || fieldInfo.IsStatic || !fieldInfo.IsDefined(typeof(DataMemberAttribute)))))
                 {
                     continue;
                 }
@@ -70,7 +66,7 @@ public override void GenerateProperties(JsonSchema schema, ContextualType contex
 
                 if (!ignored)
                 {
-                    var propertyTypeDescription = ((IReflectionService)this).GetDescription(accessorInfo.AccessorType, settings);
+                    var propertyTypeDescription = GetDescription(accessorInfo.AccessorType, settings.DefaultReferenceTypeNullHandling, settings);
                     var propertyName = GetPropertyName(accessorInfo, settings);
 
                     var propertyAlreadyExists = schema.Properties.ContainsKey(propertyName);
@@ -82,7 +78,7 @@ public override void GenerateProperties(JsonSchema schema, ContextualType contex
                         }
                         else
                         {
-                            throw new InvalidOperationException("The JSON property '" + propertyName + "' is defined multiple times on type '" + contextualType.Type.FullName + "'.");
+                            throw new InvalidOperationException($"The JSON property '{propertyName}' is defined multiple times on type '{contextualType.Type.FullName}'.");
                         }
                     }
 
@@ -104,17 +100,16 @@ public override void GenerateProperties(JsonSchema schema, ContextualType contex
             }
         }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override bool IsStringEnum(ContextualType contextualType, SystemTextJsonSchemaGeneratorSettings settings)
         {
             var hasGlobalStringEnumConverter = settings.SerializerOptions.Converters.OfType<JsonStringEnumConverter>().Any();
             return hasGlobalStringEnumConverter || base.IsStringEnum(contextualType, settings);
         }
 
-        /// <inheritdocs />
-        public override string ConvertEnumValue(object value, SystemTextJsonSchemaGeneratorSettings settings)
+        /// <inheritdoc />
+        public override Func<object, string?> GetEnumValueConverter(SystemTextJsonSchemaGeneratorSettings settings)
         {
-            // TODO(performance): How to improve this one here?
             var serializerOptions = new JsonSerializerOptions();
             foreach (var converter in settings.SerializerOptions.Converters)
             {
@@ -126,17 +121,16 @@ public override string ConvertEnumValue(object value, SystemTextJsonSchemaGenera
                 serializerOptions.Converters.Add(new JsonStringEnumConverter());
             }
 
-            var json = JsonSerializer.Serialize(value, value.GetType(), serializerOptions);
-            return JsonSerializer.Deserialize<string>(json)!;
+            return x => JsonSerializer.Deserialize<string?>(JsonSerializer.Serialize(x, x.GetType(), serializerOptions));
         }
 
-        /// <inheritdocs />
+        /// <inheritdoc />
         public override string GetPropertyName(ContextualAccessorInfo accessorInfo, JsonSchemaGeneratorSettings settings)
         {
             return GetPropertyName(accessorInfo, (SystemTextJsonSchemaGeneratorSettings)settings);
         }
 
-        private string GetPropertyName(ContextualAccessorInfo accessorInfo, SystemTextJsonSchemaGeneratorSettings settings)
+        private static string GetPropertyName(ContextualAccessorInfo accessorInfo, SystemTextJsonSchemaGeneratorSettings settings)
         {
             dynamic? jsonPropertyNameAttribute = accessorInfo.ContextAttributes
                 .FirstAssignableToTypeNameOrDefault("System.Text.Json.Serialization.JsonPropertyNameAttribute", TypeNameStyle.FullName);

src/NJsonSchema/JsonPathUtilities.cs

@@ -94,7 +94,7 @@ public static class JsonPathUtilities
             if (searchedObjects.ContainsKey(obj))
             {
                 searchedObjects[obj] = basePath;
-                if (searchedObjects.All(p => p.Value != null))
+                if (searchedObjects.All(static p => p.Value != null))
                 {
                     return true;
                 }