Improve ClassTemplateModel performance (#1786)

Author: lahma

src/NJsonSchema.CodeGeneration.CSharp/CSharpGenerator.cs

@@ -113,18 +113,18 @@ private CodeArtifact GenerateClass(JsonSchema schema, string typeName)
         {
             var model = new ClassTemplateModel(typeName, Settings, _resolver, schema, RootObject);
 
-            RenamePropertyWithSameNameAsClass(typeName, model.Properties);
+            RenamePropertyWithSameNameAsClass(typeName, model._properties);
 
             var template = Settings.TemplateFactory.CreateTemplate("CSharp", "Class", model);
             return new CodeArtifact(typeName, model.BaseClassName, CodeArtifactType.Class, CodeArtifactLanguage.CSharp, CodeArtifactCategory.Contract, template);
         }
 
-        private static void RenamePropertyWithSameNameAsClass(string typeName, IEnumerable<PropertyModel> properties)
+        private static void RenamePropertyWithSameNameAsClass(string typeName, List<PropertyModel> properties)
         {
-            var propertyModels = properties as PropertyModel[] ?? properties.ToArray();
             PropertyModel? propertyWithSameNameAsClass = null;
-            foreach (var p in propertyModels)
+            for (var i = 0; i < properties.Count; i++)
             {
+                var p = properties[i];
                 if (p.PropertyName == typeName)
                 {
                     propertyWithSameNameAsClass = p;
@@ -136,7 +136,7 @@ private static void RenamePropertyWithSameNameAsClass(string typeName, IEnumerab
             {
                 var number = 1;
                 var candidate = typeName + number;
-                while (propertyModels.Any(p => p.PropertyName == candidate))
+                while (properties.Exists(p => p.PropertyName == candidate))
                 {
                     number++;
                 }

src/NJsonSchema.CodeGeneration.CSharp/Models/ClassTemplateModel.cs

@@ -16,6 +16,8 @@ public class ClassTemplateModel : ClassTemplateModelBase
         private readonly CSharpTypeResolver _resolver;
         private readonly JsonSchema _schema;
         private readonly CSharpGeneratorSettings _settings;
+        internal readonly List<PropertyModel> _properties;
+        private readonly List<PropertyModel> _allProperties;
 
         /// <summary>Initializes a new instance of the <see cref="ClassTemplateModel"/> class.</summary>
         /// <param name="typeName">Name of the type.</param>
@@ -32,19 +34,27 @@ public ClassTemplateModel(string typeName, CSharpGeneratorSettings settings,
             _settings = settings;
 
             ClassName = typeName;
-            Properties = _schema.ActualProperties.Values
-                .Where(p => !p.IsInheritanceDiscriminator)
-                .Select(property => new PropertyModel(this, property, _resolver, _settings))
-                .ToArray();
+
+            var actualProperties = _schema.ActualProperties;
+            _properties = new List<PropertyModel>(actualProperties.Count);
+            foreach (var property in actualProperties.Values)
+            {
+                if (!property.IsInheritanceDiscriminator)
+                {
+                    _properties.Add(new PropertyModel(this, property, _resolver, _settings));
+                }
+            }
 
             if (schema.InheritedSchema != null)
             {
                 BaseClass = new ClassTemplateModel(BaseClassName!, settings, resolver, schema.InheritedSchema, rootObject);
-                AllProperties = Properties.Concat(BaseClass.AllProperties).ToArray();
+                _allProperties = new List<PropertyModel>(_properties.Count + BaseClass._allProperties.Count);
+                _allProperties.AddRange(_properties);
+                _allProperties.AddRange(BaseClass._allProperties);
             }
             else
             {
-                AllProperties = Properties;
+                _allProperties = _properties;
             }
         }
 
@@ -87,10 +97,10 @@ public ClassTemplateModel(string typeName, CSharpGeneratorSettings settings,
         //    string.Empty) : null;
 
         /// <summary>Gets the property models.</summary>
-        public IEnumerable<PropertyModel> Properties { get; }
+        public IEnumerable<PropertyModel> Properties => _properties;
 
         /// <summary>Gets the property models with inherited properties.</summary>
-        public IEnumerable<PropertyModel> AllProperties { get; }
+        public IEnumerable<PropertyModel> AllProperties => _allProperties;
 
         /// <summary>Gets a value indicating whether the class has description.</summary>
         public bool HasDescription => _schema is not JsonSchemaProperty &&