Make the HttpParser a singleton (#2203)

- It's completely stateless so make it a singleton
- Fixed tests

benchmarks/Kestrel.Performance/Http1ConnectionParsingOverheadBenchmark.cs

@@ -29,7 +29,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
             var serviceContext = new ServiceContext
             {
                 ServerOptions = new KestrelServerOptions(),
-                HttpParserFactory = f => NullParser<Http1ParsingHandler>.Instance
+                HttpParser = NullParser<Http1ParsingHandler>.Instance
             };
 
             var http1Connection = new Http1Connection<object>(application: null, context: new Http1ConnectionContext

benchmarks/Kestrel.Performance/Http1WritingBenchmark.cs

@@ -104,7 +104,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
                     DateHeaderValueManager = new DateHeaderValueManager(),
                     ServerOptions = new KestrelServerOptions(),
                     Log = new MockTrace(),
-                    HttpParserFactory = f => new HttpParser<Http1ParsingHandler>()
+                    HttpParser = new HttpParser<Http1ParsingHandler>()
                 };
 
                 var http1Connection = new TestHttp1Connection<object>(

benchmarks/Kestrel.Performance/HttpProtocolFeatureCollection.cs

@@ -86,7 +86,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
                 DateHeaderValueManager = new DateHeaderValueManager(),
                 ServerOptions = new KestrelServerOptions(),
                 Log = new MockTrace(),
-                HttpParserFactory = f => new HttpParser<Http1ParsingHandler>()
+                HttpParser = new HttpParser<Http1ParsingHandler>()
             };
 
             var http1Connection = new Http1Connection<object>(application: null, context: new Http1ConnectionContext

benchmarks/Kestrel.Performance/RequestParsingBenchmark.cs

@@ -30,7 +30,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
                 DateHeaderValueManager = new DateHeaderValueManager(),
                 ServerOptions = new KestrelServerOptions(),
                 Log = new MockTrace(),
-                HttpParserFactory = f => new HttpParser<Http1ParsingHandler>()
+                HttpParser = new HttpParser<Http1ParsingHandler>()
             };
 
             var http1Connection = new Http1Connection<object>(application: null, context: new Http1ConnectionContext

benchmarks/Kestrel.Performance/ResponseHeaderCollectionBenchmark.cs

@@ -179,7 +179,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
                 DateHeaderValueManager = new DateHeaderValueManager(),
                 ServerOptions = new KestrelServerOptions(),
                 Log = new MockTrace(),
-                HttpParserFactory = f => new HttpParser<Http1ParsingHandler>()
+                HttpParser = new HttpParser<Http1ParsingHandler>()
             };
 
             var http1Connection = new Http1Connection<object>(application: null, context: new Http1ConnectionContext

benchmarks/Kestrel.Performance/ResponseHeadersWritingBenchmark.cs

@@ -119,7 +119,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
                 DateHeaderValueManager = new DateHeaderValueManager(),
                 ServerOptions = new KestrelServerOptions(),
                 Log = new MockTrace(),
-                HttpParserFactory = f => new HttpParser<Http1ParsingHandler>()
+                HttpParser = new HttpParser<Http1ParsingHandler>()
             };
 
             var http1Connection = new TestHttp1Connection<object>(

src/Kestrel.Core/Internal/Http/Http1Connection.cs

@@ -35,7 +35,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             : base(context)
         {
             _context = context;
-            _parser = ServiceContext.HttpParserFactory(new Http1ParsingHandler(this));
+            _parser = ServiceContext.HttpParser;
             _keepAliveTicks = ServerOptions.Limits.KeepAliveTimeout.Ticks;
             _requestHeadersTimeoutTicks = ServerOptions.Limits.RequestHeadersTimeout.Ticks;
 

src/Kestrel.Core/Internal/ServiceContext.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
 
         public IThreadPool ThreadPool { get; set; }
 
-        public Func<Http1ParsingHandler, IHttpParser<Http1ParsingHandler>> HttpParserFactory { get; set; }
+        public IHttpParser<Http1ParsingHandler> HttpParser { get; set; }
 
         public ISystemClock SystemClock { get; set; }
 

src/Kestrel.Core/KestrelServer.cs

@@ -101,7 +101,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
             return new ServiceContext
             {
                 Log = trace,
-                HttpParserFactory = handler => new HttpParser<Http1ParsingHandler>(handler.Connection.ServiceContext.Log.IsEnabled(LogLevel.Information)),
+                HttpParser = new HttpParser<Http1ParsingHandler>(trace.IsEnabled(LogLevel.Information)),
                 ThreadPool = threadPool,
                 SystemClock = systemClock,
                 DateHeaderValueManager = dateHeaderValueManager,

test/Kestrel.Core.Tests/KestrelServerTests.cs

@@ -188,6 +188,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void LoggerCategoryNameIsKestrelServerNamespace()
         {
             var mockLoggerFactory = new Mock<ILoggerFactory>();
+            var mockLogger = new Mock<ILogger>();
+            mockLoggerFactory.Setup(m => m.CreateLogger(It.IsAny<string>())).Returns(mockLogger.Object);
             new KestrelServer(Options.Create<KestrelServerOptions>(null), Mock.Of<ITransportFactory>(), mockLoggerFactory.Object);
             mockLoggerFactory.Verify(factory => factory.CreateLogger("Microsoft.AspNetCore.Server.Kestrel"));
         }
@@ -195,8 +197,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         [Fact]
         public void StartWithNoTransportFactoryThrows()
         {
+            var mockLoggerFactory = new Mock<ILoggerFactory>();
+            var mockLogger = new Mock<ILogger>();
+            mockLoggerFactory.Setup(m => m.CreateLogger(It.IsAny<string>())).Returns(mockLogger.Object);
             var exception = Assert.Throws<ArgumentNullException>(() =>
-                new KestrelServer(Options.Create<KestrelServerOptions>(null), null, Mock.Of<ILoggerFactory>()));
+                new KestrelServer(Options.Create<KestrelServerOptions>(null), null, mockLoggerFactory.Object));
 
             Assert.Equal("transportFactory", exception.ParamName);
         }
@@ -231,7 +236,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 .Setup(transportFactory => transportFactory.Create(It.IsAny<IEndPointInformation>(), It.IsAny<IConnectionHandler>()))
                 .Returns(mockTransport.Object);
 
-            var server = new KestrelServer(Options.Create(options), mockTransportFactory.Object, Mock.Of<LoggerFactory>());
+            var mockLoggerFactory = new Mock<ILoggerFactory>();
+            var mockLogger = new Mock<ILogger>();
+            mockLoggerFactory.Setup(m => m.CreateLogger(It.IsAny<string>())).Returns(mockLogger.Object);
+            var server = new KestrelServer(Options.Create(options), mockTransportFactory.Object, mockLoggerFactory.Object);
             await server.StartAsync(new DummyApplication(), CancellationToken.None);
 
             var stopTask1 = server.StopAsync(default(CancellationToken));
@@ -285,7 +293,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
                 .Setup(transportFactory => transportFactory.Create(It.IsAny<IEndPointInformation>(), It.IsAny<IConnectionHandler>()))
                 .Returns(mockTransport.Object);
 
-            var server = new KestrelServer(Options.Create(options), mockTransportFactory.Object, Mock.Of<LoggerFactory>());
+            var mockLoggerFactory = new Mock<ILoggerFactory>();
+            var mockLogger = new Mock<ILogger>();
+            mockLoggerFactory.Setup(m => m.CreateLogger(It.IsAny<string>())).Returns(mockLogger.Object);
+            var server = new KestrelServer(Options.Create(options), mockTransportFactory.Object, mockLoggerFactory.Object);
             await server.StartAsync(new DummyApplication(), CancellationToken.None);
 
             var stopTask1 = server.StopAsync(default(CancellationToken));

test/Kestrel.Transport.Libuv.Tests/ListenerPrimaryTests.cs

@@ -110,7 +110,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
                 DateHeaderValueManager = serviceContextPrimary.DateHeaderValueManager,
                 ServerOptions = serviceContextPrimary.ServerOptions,
                 ThreadPool = serviceContextPrimary.ThreadPool,
-                HttpParserFactory = serviceContextPrimary.HttpParserFactory,
+                HttpParser = serviceContextPrimary.HttpParser,
             };
             var builderSecondary = new ConnectionBuilder();
             builderSecondary.UseHttpServer(serviceContextSecondary, new DummyApplication(c => c.Response.WriteAsync("Secondary")), HttpProtocols.Http1);
@@ -221,7 +221,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
                 DateHeaderValueManager = serviceContextPrimary.DateHeaderValueManager,
                 ServerOptions = serviceContextPrimary.ServerOptions,
                 ThreadPool = serviceContextPrimary.ThreadPool,
-                HttpParserFactory = serviceContextPrimary.HttpParserFactory,
+                HttpParser = serviceContextPrimary.HttpParser,
             };
             var builderSecondary = new ConnectionBuilder();
             builderSecondary.UseHttpServer(serviceContextSecondary, new DummyApplication(c => c.Response.WriteAsync("Secondary")), HttpProtocols.Http1);

test/shared/TestServiceContext.cs

@@ -39,7 +39,7 @@ namespace Microsoft.AspNetCore.Testing
             SystemClock = new MockSystemClock();
             DateHeaderValueManager = new DateHeaderValueManager(SystemClock);
             ConnectionManager = new HttpConnectionManager(Log, ResourceCounter.Unlimited);
-            HttpParserFactory = handler => new HttpParser<Http1ParsingHandler>(handler.Connection.ServiceContext.Log.IsEnabled(LogLevel.Information));
+            HttpParser = new HttpParser<Http1ParsingHandler>(Log.IsEnabled(LogLevel.Information));
             ServerOptions = new KestrelServerOptions
             {
                 AddServerHeader = false