Merge

src/NSwag.AspNetCore/AspNetCoreToOpenApiMiddlewareSettings.cs

@@ -0,0 +1,34 @@
+//-----------------------------------------------------------------------
+// <copyright file="AspNetCoreToOpenApiMiddlewareSettings.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using NSwag.AspNetCore.Middlewares;
+
+namespace NSwag.AspNetCore
+{
+    /// <summary>
+    /// The settings for <see cref="OpenApiExtensions.UseOpenApi"/> and <see cref="AspNetCoreToOpenApiMiddleware"/>.
+    /// </summary>
+    /// <remarks>
+    /// Reviewers: Is it useful to have a post-processing step i.e. PostProcess property here that all documents share?
+    /// </remarks>
+    public class AspNetCoreToOpenApiMiddlewareSettings
+    {
+        /// <summary>
+        /// Gets or sets the Swagger URL route. Must start with '/' and should contain a '{documentName}' route
+        /// parameter.
+        /// </summary>
+        public string SwaggerRoute { get; set; } = "/swagger/{documentName}/swagger.json";
+
+        /// <summary>
+        /// Gets or sets for how long an <see cref="Exception"/> caught during schema generation is cached.
+        /// </summary>
+        public TimeSpan ExceptionCacheTime { get; set; } = TimeSpan.FromSeconds(10);
+    }
+}

src/NSwag.AspNetCore/DependencyInjection/IOpenApiBuilder.cs

@@ -0,0 +1,23 @@
+//-----------------------------------------------------------------------
+// <copyright file="IOpenApiBuilder.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using Microsoft.Extensions.DependencyInjection;
+
+namespace NSwag.AspNetCore.DependencyInjection
+{
+    /// <summary>
+    /// An interface for configuring Open Api documents.
+    /// </summary>
+    public interface IOpenApiBuilder
+    {
+        /// <summary>
+        /// Gets the <see cref="IServiceCollection"/>.
+        /// </summary>
+        IServiceCollection Services { get; }
+    }
+}

src/NSwag.AspNetCore/DependencyInjection/OpenApiBuilder.cs

@@ -0,0 +1,22 @@
+//-----------------------------------------------------------------------
+// <copyright file="OpenApiBuilder.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using Microsoft.Extensions.DependencyInjection;
+
+namespace NSwag.AspNetCore.DependencyInjection
+{
+    internal class OpenApiBuilder : IOpenApiBuilder
+    {
+        public OpenApiBuilder(IServiceCollection services)
+        {
+            Services = services;
+        }
+
+        public IServiceCollection Services { get; }
+    }
+}

src/NSwag.AspNetCore/DocumentRegistry.cs

@@ -8,44 +8,45 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
 
 namespace NSwag.AspNetCore
 {
     internal class DocumentRegistry
     {
-        private readonly Dictionary<string, RegisteredDocument> _documents;
+        private readonly Dictionary<string, OpenApiDocumentSettings> _documentSettings;
 
-        public DocumentRegistry()
+        public DocumentRegistry(IEnumerable<OpenApiDocumentSettings> documentSettings)
         {
-            _documents = new Dictionary<string, RegisteredDocument>(StringComparer.Ordinal);
-        }
-
-        public RegisteredDocument this[string documentName]
-        {
-            get
+            _documentSettings = new Dictionary<string, OpenApiDocumentSettings>(StringComparer.Ordinal);
+            foreach (var settings in documentSettings)
             {
-                if (documentName == null)
+                if (_documentSettings.ContainsKey(settings.DocumentName))
                 {
-                    throw new ArgumentNullException(nameof(documentName));
+                    throw new InvalidOperationException($"Repeated document name '{settings.DocumentName}' in " +
+                        "registry. Open API document names must be unique.");
                 }
 
-                _documents.TryGetValue(documentName, out var document);
-                return document;
+                _documentSettings[settings.DocumentName] = settings;
             }
 
-            set
+            DocumentNames = new ReadOnlyCollection<string>(_documentSettings.Keys.ToList());
+        }
+
+        public IReadOnlyCollection<string> DocumentNames { get; }
+
+        public OpenApiDocumentSettings this[string documentName]
+        {
+            get
             {
                 if (documentName == null)
                 {
                     throw new ArgumentNullException(nameof(documentName));
                 }
 
-                if (value == null)
-                {
-                    throw new ArgumentNullException(nameof(value));
-                }
-
-                _documents[documentName] = value;
+                _documentSettings.TryGetValue(documentName, out var document);
+                return document;
             }
         }
     }

src/NSwag.AspNetCore/Middlewares/AspNetCoreToOpenApiMiddleware.cs

@@ -0,0 +1,92 @@
+//-----------------------------------------------------------------------
+// <copyright file="AspNetCoreToOpenApiMiddleware.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using System;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.AspNetCore.Routing.Internal;
+using Microsoft.AspNetCore.Routing.Template;
+using Microsoft.Extensions.ObjectPool;
+
+namespace NSwag.AspNetCore.Middlewares
+{
+    internal class AspNetCoreToOpenApiMiddleware
+    {
+        private const string DocumentNameEntry = "documentName";
+        private readonly NSwagDocumentProvider _documentProvider;
+        private readonly TemplateMatcher _matcher;
+        private readonly RequestDelegate _nextDelegate;
+        private readonly AspNetCoreToOpenApiMiddlewareSettings _settings;
+
+        private string _failedDocumentName;
+        private Exception _documentException;
+        private DateTimeOffset _exceptionTimestamp;
+
+        public AspNetCoreToOpenApiMiddleware(
+            RequestDelegate nextDelegate,
+            NSwagDocumentProvider documentProvider,
+            ObjectPool<UriBuildingContext> pool,
+            AspNetCoreToOpenApiMiddlewareSettings settings)
+        {
+            _documentProvider = documentProvider;
+
+            var template = TemplateParser.Parse(settings.SwaggerRoute);
+            _matcher = new TemplateMatcher(template, defaults: null);
+            _nextDelegate = nextDelegate;
+            _settings = settings;
+        }
+
+        public async Task Invoke(HttpContext context)
+        {
+            var values = new RouteValueDictionary();
+            if (_matcher.TryMatch(context.Request.Path, values))
+            {
+                var documentName = "v1";
+                if (values.TryGetValue(DocumentNameEntry, out var document))
+                {
+                    documentName = document as string;
+                    if (documentName == null)
+                    {
+                        throw new InvalidOperationException($"Unexpected null '{DocumentNameEntry}' entry in " +
+                            $"{nameof(RouteValueDictionary)}.");
+                    }
+                }
+
+                var documentString = await GenerateOpenApiAsync(documentName);
+                context.Response.StatusCode = 200;
+                context.Response.Headers["Content-Type"] = "application/json; charset=utf-8";
+                await context.Response.WriteAsync(documentString);
+            }
+            else
+                await _nextDelegate(context);
+        }
+
+        protected virtual async Task<string> GenerateOpenApiAsync(string documentName)
+        {
+            var now = DateTimeOffset.UtcNow;
+            if (_documentException != null &&
+                _exceptionTimestamp + _settings.ExceptionCacheTime > now &&
+                string.Equals(_failedDocumentName, documentName, StringComparison.Ordinal))
+                throw _documentException;
+
+            try
+            {
+                return await _documentProvider.GenerateAsync(documentName);
+            }
+            catch (Exception exception)
+            {
+                _documentException = exception;
+                _exceptionTimestamp = now;
+                _failedDocumentName = documentName;
+
+                throw _documentException;
+            }
+        }
+    }
+}

src/NSwag.AspNetCore/NSwagDocumentProvider.cs

@@ -8,6 +8,7 @@
 
 using System;
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.ApiExplorer;
@@ -24,6 +25,10 @@ internal class NSwagDocumentProvider : IDocumentProvider
         private readonly IOptions<MvcJsonOptions> _mvcJsonOptions;
         private readonly DocumentRegistry _registry;
 
+        private int _version;
+        private string _lastDocument;
+        private string _lastDocumentName;
+
         public NSwagDocumentProvider(
             DocumentRegistry registry,
             IApiDescriptionGroupCollectionProvider apiDescriptionGroupCollectionProvider,
@@ -56,35 +61,28 @@ public NSwagDocumentProvider(
             _registry = registry;
         }
 
-        public async Task<SwaggerDocument> GenerateAsync(string documentName)
+        public async Task<string> GenerateAsync(string documentName)
         {
             if (documentName == null)
             {
                 throw new ArgumentNullException(nameof(documentName));
             }
 
-            var documentInfo = _registry[documentName];
-            if (documentInfo == null)
+            var apiDescriptionGroups = _apiDescriptionGroupCollectionProvider.ApiDescriptionGroups;
+            var newVersion = apiDescriptionGroups.Version;
+            if (_lastDocument != null &&
+                string.Equals(_lastDocumentName, documentName, StringComparison.Ordinal) &&
+                newVersion == Volatile.Read(ref _version))
             {
-                throw new InvalidOperationException($"No registered document found for document name '{documentName}'.");
+                return _lastDocument;
             }
 
-            documentInfo.Settings.ApplySettings(_mvcJsonOptions.Value.SerializerSettings, _mvcOptions.Value);
+            var document = await GenerateAsyncCore(documentName);
+            _lastDocument = document.ToJson();
+            _lastDocumentName = documentName;
+            Volatile.Write(ref _version, newVersion);
 
-            SwaggerDocument document;
-            if (documentInfo.Settings is AspNetCoreToSwaggerGeneratorSettings aspnetcore)
-            {
-                var generator = new AspNetCoreToSwaggerGenerator(aspnetcore, documentInfo.SchemaGenerator);
-                document = await generator.GenerateAsync(_apiDescriptionGroupCollectionProvider.ApiDescriptionGroups);
-            }
-            else
-            {
-                throw new InvalidOperationException($"Unsupported settings type '{documentInfo.GetType().FullName}");
-            }
-
-            documentInfo.PostProcess?.Invoke(document);
-
-            return document;
+            return _lastDocument;
         }
 
         // Called by the Microsoft.Extensions.ApiDescription tool
@@ -100,10 +98,33 @@ async Task IDocumentProvider.GenerateAsync(string documentName, TextWriter write
                 throw new ArgumentNullException(nameof(writer));
             }
 
-            var document = await GenerateAsync(documentName);
+            var document = await GenerateAsyncCore(documentName);
 
             var json = document.ToJson();
             await writer.WriteAsync(json);
         }
+
+        private async Task<SwaggerDocument> GenerateAsyncCore(string documentName)
+        {
+            var documentSettings = _registry[documentName];
+            if (documentSettings == null)
+            {
+                throw new InvalidOperationException(
+                    $"No registered document found for document name '{documentName}'.");
+            }
+
+            documentSettings.GeneratorSettings.ApplySettings(
+                _mvcJsonOptions.Value.SerializerSettings,
+                _mvcOptions.Value);
+
+            var generator = new AspNetCoreToSwaggerGenerator(
+                documentSettings.GeneratorSettings,
+                documentSettings.SchemaGenerator);
+            var document = await generator.GenerateAsync(_apiDescriptionGroupCollectionProvider.ApiDescriptionGroups);
+
+            documentSettings.PostProcess?.Invoke(document);
+
+            return document;
+        }
     }
 }