Improve OpenApiOperation ActualResponses and Responses performance

src/NSwag.CodeGeneration.CSharp/Models/CSharpClientTemplateModel.cs

@@ -195,7 +195,7 @@ public string JsonConvertersArrayCode
         private bool RequiresJsonExceptionConverter =>
             _settings.CSharpGeneratorSettings.JsonLibrary == CSharpJsonLibrary.NewtonsoftJson &&
             _settings.CSharpGeneratorSettings.ExcludedTypeNames?.Contains("JsonExceptionConverter") != true &&
-            _document.Operations.Any(o => o.Operation.ActualResponses.Any(r => r.Value.Schema?.InheritsSchema(_exceptionSchema) == true));
+            _document.Operations.Any(o => o.Operation.HasActualResponse((_, response) => response.Schema?.InheritsSchema(_exceptionSchema) == true));
 
         private static readonly string[] jsonExceptionConverterArray = ["JsonExceptionConverter"];
     }

src/NSwag.CodeGeneration.CSharp/Models/CSharpFileTemplateModel.cs

@@ -83,7 +83,7 @@ public CSharpFileTemplateModel(
         public string ExceptionModelClass => JsonExceptionTypes.FirstOrDefault(t => t != "Exception") ?? "Exception";
 
         private IEnumerable<string> JsonExceptionTypes => _document.Operations
-            .SelectMany(o => o.Operation.ActualResponses.Where(r => r.Value.Schema?.InheritsSchema(_resolver.ExceptionSchema) == true).Select(r => new { o.Operation, Response = r.Value }))
+            .SelectMany(o => o.Operation.GetActualResponses((_, response) => response.Schema?.InheritsSchema(_resolver.ExceptionSchema) == true).Select(r => new { o.Operation, Response = r.Value }))
             .Select(t => _generator.GetTypeName(t.Response.Schema, t.Response.IsNullable(_settings.CSharpGeneratorSettings.SchemaType), "Response"));
 
         /// <summary>Gets a value indicating whether the generated code requires the FileParameter type.</summary>
@@ -99,7 +99,7 @@ public CSharpFileTemplateModel(
         /// <summary>Gets a value indicating whether [generate file response class].</summary>
         public bool GenerateFileResponseClass =>
             _settings.CSharpGeneratorSettings.ExcludedTypeNames?.Contains("FileResponse") != true &&
-            _document.Operations.Any(o => o.Operation.ActualResponses.Any(r => r.Value.IsBinary(o.Operation)));
+            _document.Operations.Any(o => o.Operation.HasActualResponse((_, response) => response.IsBinary(o.Operation)));
 
         /// <summary>Gets or sets a value indicating whether to generate exception classes (default: true).</summary>
         public bool GenerateExceptionClasses => _settings is CSharpClientGeneratorSettings { GenerateExceptionClasses: true };

src/NSwag.CodeGeneration.CSharp/Models/CSharpOperationModel.cs

@@ -143,14 +143,14 @@ public override string ExceptionType
         {
             get
             {
-                if (_operation.ActualResponses.Count(r => !HttpUtilities.IsSuccessStatusCode(r.Key)) != 1)
+                var response = _operation.GetActualResponse((code, _) => !HttpUtilities.IsSuccessStatusCode(code));
+                if (response == null)
                 {
                     return "System.Exception";
                 }
 
-                var response = _operation.ActualResponses.Single(r => !HttpUtilities.IsSuccessStatusCode(r.Key));
-                var isNullable = response.Value.IsNullable(_settings.CodeGeneratorSettings.SchemaType);
-                return _generator.GetTypeName(response.Value.Schema, isNullable, "Exception");
+                var isNullable = response.IsNullable(_settings.CodeGeneratorSettings.SchemaType);
+                return _generator.GetTypeName(response.Schema, isNullable, "Exception");
             }
         }
 

src/NSwag.CodeGeneration.CSharp/NSwag.CodeGeneration.CSharp.csproj

@@ -6,7 +6,6 @@
 
   <ItemGroup>
     <EmbeddedResource Include="Templates\*.liquid" />
-    <Compile Include="..\NSwag.Core\Polyfills.cs" Link="Polyfills.cs" />
   </ItemGroup>
 
   <ItemGroup>

src/NSwag.CodeGeneration.TypeScript/Models/TypeScriptFileTemplateModel.cs

@@ -140,7 +140,7 @@ public IEnumerable<string> ResponseClassNames
         public bool RequiresFileResponseInterface =>
             !Framework.IsJQuery &&
             !_settings.TypeScriptGeneratorSettings.ExcludedTypeNames.Contains("FileResponse") &&
-            _document.Operations.Any(o => o.Operation.ActualResponses.Any(r => r.Value.IsBinary(o.Operation)));
+            _document.Operations.Any(o => o.Operation.HasActualResponse((_, response) => response.IsBinary(o.Operation)));
 
         /// <summary>Gets a value indicating whether the client functions are required.</summary>
         public bool RequiresClientFunctions =>

src/NSwag.CodeGeneration.TypeScript/Models/TypeScriptOperationModel.cs

@@ -123,12 +123,13 @@ public override string ExceptionType
         {
             get
             {
-                if (_operation.ActualResponses.All(r => HttpUtilities.IsSuccessStatusCode(r.Key)))
+                var actualResponses = _operation.ActualResponses;
+                if (actualResponses.All(static r => HttpUtilities.IsSuccessStatusCode(r.Key)))
                 {
                     return "string";
                 }
 
-                return string.Join(" | ", _operation.ActualResponses
+                return string.Join(" | ", actualResponses
                     .Where(r => !HttpUtilities.IsSuccessStatusCode(r.Key) && r.Value.Schema != null)
                     .Select(r => _generator.GetTypeName(r.Value.Schema, r.Value.IsNullable(_settings.CodeGeneratorSettings.SchemaType), "Exception"))
                     .Concat(["string"]));

src/NSwag.CodeGeneration/Models/OperationModelBase.cs

@@ -34,7 +34,7 @@ protected OperationModelBase(JsonSchema exceptionSchema, OpenApiOperation operat
             _generator = generator;
             _settings = settings;
 
-            var responses = _operation.ActualResponses
+            var responses = _operation.GetActualResponses(static (_, _) => true)
                 .Select(response => CreateResponseModel(operation, response.Key, response.Value, exceptionSchema, generator, resolver, settings))
                 .ToList();
 
@@ -295,21 +295,7 @@ public string Produces
         }
 
         /// <summary>Gets a value indicating whether a file response is expected from one of the responses.</summary>
-        public bool IsFile
-        {
-            get
-            {
-                foreach (var r in _operation.ActualResponses)
-                {
-                    if (r.Value.IsBinary(_operation))
-                    {
-                        return true;
-                    }
-                }
-
-                return false;
-            }
-        }
+        public bool IsFile => _operation.HasActualResponse((_, response) => response.IsBinary(_operation));
 
         /// <summary>Gets a value indicating whether to wrap the response of this operation.</summary>
         public bool WrapResponse => _settings.WrapResponses && (
@@ -324,18 +310,7 @@ public bool IsFile
         /// <returns>The response.</returns>
         protected KeyValuePair<string, OpenApiResponse> GetSuccessResponse()
         {
-            if (_operation.ActualResponses.TryGetValue("200", out var response200))
-            {
-                return new KeyValuePair<string, OpenApiResponse>("200", response200);
-            }
-
-            var response = _operation.ActualResponses.FirstOrDefault(static r => HttpUtilities.IsSuccessStatusCode(r.Key));
-            if (response.Value != null)
-            {
-                return new KeyValuePair<string, OpenApiResponse>(response.Key, response.Value);
-            }
-
-            return new KeyValuePair<string, OpenApiResponse>("default", _operation.ActualResponses.FirstOrDefault(r => r.Key == "default").Value);
+            return _operation.GetSuccessResponse();
         }
 
         /// <summary>Gets the name of the parameter variable.</summary>

src/NSwag.Core/NSwag.Core.csproj

@@ -1,10 +1,19 @@
 <Project Sdk="Microsoft.NET.Sdk">
+
   <PropertyGroup>
     <TargetFrameworks>net462;netstandard2.0</TargetFrameworks>
     <RootNamespace>NSwag</RootNamespace>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
   </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="NJsonSchema" Version="11.2.0" />
   </ItemGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="NSwag.CodeGeneration, PublicKey=0024000004800000940000000602000000240000525341310004000001000100eba55a5211cd3198b5ba4b96c5cb70484b376ce083664d47dcb7439a97c3368a26ea54de3ec6d90d2899d39c4e3b65cb4ac7ef8ba5c9ded7c8aa6538757b31291624e96f374c23fdbeeaa85dfe841ab6afffbd3593d2a40c96a0f0888f25d7bd9361611db9450041b57776d33e3acb90794254c428251ddd63aa329d86ec809f" />
+    <InternalsVisibleTo Include="NSwag.CodeGeneration.CSharp, PublicKey=0024000004800000940000000602000000240000525341310004000001000100eba55a5211cd3198b5ba4b96c5cb70484b376ce083664d47dcb7439a97c3368a26ea54de3ec6d90d2899d39c4e3b65cb4ac7ef8ba5c9ded7c8aa6538757b31291624e96f374c23fdbeeaa85dfe841ab6afffbd3593d2a40c96a0f0888f25d7bd9361611db9450041b57776d33e3acb90794254c428251ddd63aa329d86ec809f" />
+    <InternalsVisibleTo Include="NSwag.CodeGeneration.TypeScript, PublicKey=0024000004800000940000000602000000240000525341310004000001000100eba55a5211cd3198b5ba4b96c5cb70484b376ce083664d47dcb7439a97c3368a26ea54de3ec6d90d2899d39c4e3b65cb4ac7ef8ba5c9ded7c8aa6538757b31291624e96f374c23fdbeeaa85dfe841ab6afffbd3593d2a40c96a0f0888f25d7bd9361611db9450041b57776d33e3acb90794254c428251ddd63aa329d86ec809f"  />
+  </ItemGroup>
+
 </Project>

src/NSwag.Core/OpenApiDocument.cs

@@ -268,9 +268,9 @@ public void GenerateOperationIds()
             {
                 if (group.Count() > 1)
                 {
-                    var collections = group.Where(o => o.Operation.ActualResponses.Any(r =>
-                              HttpUtilities.IsSuccessStatusCode(r.Key) &&
-                              r.Value.Schema?.ActualSchema.Type == JsonObjectType.Array));
+                    var collections = group.Where(o => o.Operation.HasActualResponse(static (code, response) =>
+                              HttpUtilities.IsSuccessStatusCode(code) &&
+                              response.Schema?.ActualSchema.Type == JsonObjectType.Array));
                     // if we have just collections, adding All will not help in discrimination
                     if (collections.Count() == group.Count())
                     {
@@ -279,9 +279,9 @@ public void GenerateOperationIds()
 
                     foreach (var o in group)
                     {
-                        var isCollection = o.Operation.ActualResponses.Any(r =>
-                            HttpUtilities.IsSuccessStatusCode(r.Key) &&
-                            r.Value.Schema?.ActualSchema.Type == JsonObjectType.Array);
+                        var isCollection = o.Operation.HasActualResponse(static (code, response) =>
+                            HttpUtilities.IsSuccessStatusCode(code) &&
+                            response.Schema?.ActualSchema.Type == JsonObjectType.Array);
 
                         if (isCollection)
                         {

src/NSwag.Core/OpenApiOperation.cs

@@ -8,6 +8,7 @@
 
 using System.Collections.ObjectModel;
 using System.Collections.Specialized;
+using System.Runtime.CompilerServices;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Converters;
 using NJsonSchema;
@@ -24,6 +25,8 @@ public class OpenApiOperation : JsonExtensionObject
         private bool _disableRequestBodyUpdate;
         private bool _disableBodyParameterUpdate;
 
+        private readonly ObservableDictionary<string, OpenApiResponse> _responses;
+
         /// <summary>Initializes a new instance of the <see cref="OpenApiPathItem"/> class.</summary>
         public OpenApiOperation()
         {
@@ -42,14 +45,14 @@ public OpenApiOperation()
             Parameters = parameters;
 
             var responses = new ObservableDictionary<string, OpenApiResponse>();
+            _responses = responses;
             responses.CollectionChanged += (sender, args) =>
             {
-                foreach (var response in Responses.Values)
+                foreach (var pair in _responses)
                 {
-                    response.Parent = this;
+                    pair.Value.Parent = this;
                 }
             };
-            Responses = responses;
         }
 
         /// <summary>Gets the parent operations list.</summary>
@@ -132,7 +135,7 @@ public IReadOnlyList<OpenApiParameter> ActualParameters
 
         /// <summary>Gets or sets the HTTP Status Code/Response pairs.</summary>
         [JsonProperty(PropertyName = "responses", Order = 10, Required = Required.Always, DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public IDictionary<string, OpenApiResponse> Responses { get; }
+        public IDictionary<string, OpenApiResponse> Responses => _responses;
 
         /// <summary>Gets or sets the schemes.</summary>
         [JsonProperty(PropertyName = "schemes", Order = 11, DefaultValueHandling = DefaultValueHandling.Ignore, ItemConverterType = typeof(StringEnumConverter))]
@@ -172,7 +175,79 @@ public IReadOnlyList<OpenApiParameter> ActualParameters
 
         /// <summary>Gets the responses from the operation and from the <see cref="OpenApiDocument"/> and dereferences them if necessary.</summary>
         [JsonIgnore]
-        public IReadOnlyDictionary<string, OpenApiResponse> ActualResponses => Responses.ToDictionary(t => t.Key, t => t.Value.ActualResponse);
+        public IReadOnlyDictionary<string, OpenApiResponse> ActualResponses
+        {
+            get
+            {
+                var dictionary = new Dictionary<string, OpenApiResponse>(_responses.Count);
+                foreach (var response in _responses)
+                {
+                    dictionary.Add(response.Key, response.Value.ActualResponse);
+                }
+                return dictionary;
+            }
+        }
+
+        // helpers to avoid extra allocations
+        internal IEnumerable<KeyValuePair<string, OpenApiResponse>> GetActualResponses(Func<string, OpenApiResponse, bool> predicate)
+        {
+            foreach (var pair in _responses)
+            {
+                if (predicate(pair.Key, pair.Value.ActualResponse))
+                {
+                    yield return new KeyValuePair<string, OpenApiResponse>(pair.Key, pair.Value.ActualResponse);
+                }
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal bool HasActualResponse(Func<string, OpenApiResponse, bool> predicate) => GetActualResponse(predicate) != null;
+
+        internal OpenApiResponse GetActualResponse(Func<string, OpenApiResponse, bool> predicate)
+        {
+            foreach (var pair in _responses)
+            {
+                if (predicate(pair.Key, pair.Value.ActualResponse))
+                {
+                    return pair.Value.ActualResponse;
+                }
+            }
+
+            return null;
+        }
+
+        internal KeyValuePair<string,OpenApiResponse> GetSuccessResponse()
+        {
+            KeyValuePair<string, OpenApiResponse> firstOtherSuccessResponse = new(null, null);
+            OpenApiResponse defaultResponse = null;
+            foreach (var pair in _responses)
+            {
+                var code = pair.Key;
+                var actualResponse = pair.Value.ActualResponse;
+
+                if (code == "200")
+                {
+                    // 200 is the default response
+                    return new KeyValuePair<string, OpenApiResponse>(code, actualResponse);
+                }
+
+                if (firstOtherSuccessResponse.Key == null && HttpUtilities.IsSuccessStatusCode(code))
+                {
+                    firstOtherSuccessResponse = new KeyValuePair<string, OpenApiResponse>(code, actualResponse);
+                }
+                else if (code == "default")
+                {
+                    defaultResponse = actualResponse;
+                }
+            }
+
+            if (firstOtherSuccessResponse.Key != null)
+            {
+                return firstOtherSuccessResponse;
+            }
+
+            return new KeyValuePair<string, OpenApiResponse>("default", defaultResponse);
+        }
 
         /// <summary>Gets the actual security description, either from the operation or from the <see cref="OpenApiDocument"/>.</summary>
         [JsonIgnore]