Move buffer types to ViewFeatures

Use buffer pooling in more places

src/Microsoft.AspNet.Mvc.Razor/Buffer/IRazorBufferScope.cs

@@ -1,17 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-namespace Microsoft.AspNet.Mvc.Razor.Buffer
-{
-    /// <summary>
-    /// Creates and manages the lifetime of <see cref="RazorBufferSegment"/> instances.
-    /// </summary>
-    public interface IRazorBufferScope
-    {
-        /// <summary>
-        /// Gets a <see cref="RazorBufferSegment"/>.
-        /// </summary>
-        /// <returns>The <see cref="RazorBufferSegment"/>.</returns>
-        RazorBufferSegment GetSegment();
-    }
-}

src/Microsoft.AspNet.Mvc.Razor/Buffer/MemoryPoolRazorBufferScope.cs

@@ -1,82 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-using Microsoft.Extensions.MemoryPool;
-
-namespace Microsoft.AspNet.Mvc.Razor.Buffer
-{
-    /// <summary>
-    /// A <see cref="IRazorBufferScope"/> that uses pooled memory.
-    /// </summary>
-    public class MemoryPoolRazorBufferScope : IRazorBufferScope, IDisposable
-    {
-        private const int SegmentSize = 1024;
-        private readonly IArraySegmentPool<RazorValue> _pool;
-        private List<LeasedArraySegment<RazorValue>> _leased;
-        private bool _disposed;
-
-        /// <summary>
-        /// Initializes a new instance of <see cref="MemoryPoolRazorBufferScope"/>.
-        /// </summary>
-        /// <param name="pool">The <see cref="IArraySegmentPool{RazorValue}"/> for creating
-        /// <see cref="RazorValue"/> instances.</param>
-        public MemoryPoolRazorBufferScope(IArraySegmentPool<RazorValue> pool)
-        {
-            _pool = pool;
-        }
-
-        /// <inheritdoc />
-        public RazorBufferSegment GetSegment()
-        {
-            if (_disposed)
-            {
-                throw new ObjectDisposedException(typeof(MemoryPoolRazorBufferScope).FullName);
-            }
-
-            if (_leased == null)
-            {
-                _leased = new List<LeasedArraySegment<RazorValue>>(1);
-            }
-
-            LeasedArraySegment<RazorValue> segment = null;
-
-            try
-            {
-                segment = _pool.Lease(SegmentSize);
-                _leased.Add(segment);
-            }
-            catch when (segment != null)
-            {
-                segment.Owner.Return(segment);
-                throw;
-            }
-
-            return new RazorBufferSegment(segment.Data);
-        }
-
-        /// <inheritdoc />
-        public void Dispose()
-        {
-            if (!_disposed)
-            {
-                _disposed = true;
-
-                if (_leased == null)
-                {
-                    return;
-                }
-
-                for (var i = 0; i < _leased.Count; i++)
-                {
-                    var segment = _leased[i];
-                    Array.Clear(segment.Data.Array, segment.Data.Offset, segment.Data.Count);
-                    segment.Owner.Return(segment);
-                }
-
-                _leased.Clear();
-            }
-        }
-    }
-}

src/Microsoft.AspNet.Mvc.Razor/Buffer/RazorBufferSegment.cs

@@ -1,27 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-
-namespace Microsoft.AspNet.Mvc.Razor.Buffer
-{
-    /// <summary>
-    /// Encapsulates a <see cref="ArraySegment{RazorValue}"/>.
-    /// </summary>
-    public struct RazorBufferSegment
-    {
-        /// <summary>
-        /// Initializes a new instance of <see cref="RazorBufferSegment"/>.
-        /// </summary>
-        /// <param name="data">The <see cref="ArraySegment{RazorValue}"/> to encapsulate.</param>
-        public RazorBufferSegment(ArraySegment<RazorValue> data)
-        {
-            Data = data;
-        }
-
-        /// <summary>
-        /// Gets the <see cref="ArraySegment{RazorValue}"/>.
-        /// </summary>
-        public ArraySegment<RazorValue> Data { get; }
-    }
-}

src/Microsoft.AspNet.Mvc.Razor/DependencyInjection/MvcRazorMvcCoreBuilderExtensions.cs

@@ -6,7 +6,6 @@ using System.Linq;
 using System.Reflection;
 using Microsoft.AspNet.Mvc;
 using Microsoft.AspNet.Mvc.Razor;
-using Microsoft.AspNet.Mvc.Razor.Buffer;
 using Microsoft.AspNet.Mvc.Razor.Compilation;
 using Microsoft.AspNet.Mvc.Razor.Directives;
 using Microsoft.AspNet.Mvc.Razor.Internal;
@@ -160,9 +159,6 @@ namespace Microsoft.Extensions.DependencyInjection
             // Consumed by the Cache tag helper to cache results across the lifetime of the application.
             services.TryAddSingleton<IMemoryCache, MemoryCache>();
 
-            services.TryAddSingleton<IArraySegmentPool<RazorValue>, DefaultArraySegmentPool<RazorValue>>();
-            services.TryAddScoped<IRazorBufferScope, MemoryPoolRazorBufferScope>();
-
             if (PlatformServices.Default?.AssemblyLoadContextAccessor != null)
             {
                 services.TryAddSingleton(PlatformServices.Default.AssemblyLoadContextAccessor);

src/Microsoft.AspNet.Mvc.Razor/RazorPage.cs

@@ -17,6 +17,7 @@ using Microsoft.AspNet.Mvc.Razor.Internal;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.Routing;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Razor.Runtime.TagHelpers;
 using Microsoft.AspNet.Razor.TagHelpers;
 using Microsoft.Extensions.DependencyInjection;
@@ -37,12 +38,12 @@ namespace Microsoft.AspNet.Mvc.Razor
         private bool _renderedBody;
         private AttributeInfo _attributeInfo;
         private TagHelperAttributeInfo _tagHelperAttributeInfo;
-        private StringCollectionTextWriter _valueBuffer;
+        private HtmlContentWrapperTextWriter _valueBuffer;
+        private IViewBufferScope _bufferScope;
 
         public RazorPage()
         {
             SectionWriters = new Dictionary<string, RenderAsyncDelegate>(StringComparer.OrdinalIgnoreCase);
-
             _writerScopes = new Stack<TextWriter>();
         }
 
@@ -148,6 +149,20 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
         }
 
+        private IViewBufferScope BufferScope
+        {
+            get
+            {
+                if (_bufferScope == null)
+                {
+                    var services = ViewContext.HttpContext.RequestServices;
+                    _bufferScope = services.GetRequiredService<IViewBufferScope>();
+                }
+
+                return _bufferScope;
+            }
+        }
+
         /// <summary>
         /// Format an error message about using an indexer when the tag helper property is <c>null</c>.
         /// </summary>
@@ -194,7 +209,8 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// </remarks>
         public void StartTagHelperWritingScope()
         {
-            StartTagHelperWritingScope(new StringCollectionTextWriter(Output.Encoding));
+            var buffer = new ViewBuffer(BufferScope, Path);
+            StartTagHelperWritingScope(new HtmlContentWrapperTextWriter(buffer, Output.Encoding));
         }
 
         /// <summary>
@@ -221,7 +237,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             // from HTML helpers) is redirected.
             ViewContext.Writer = writer;
 
-            _writerScopes.Push(ViewContext.Writer);
+            _writerScopes.Push(writer);
         }
 
         /// <summary>
@@ -258,10 +274,10 @@ namespace Microsoft.AspNet.Mvc.Razor
             }
             else
             {
-                var stringCollectionTextWriter = writer as StringCollectionTextWriter;
+                var htmlContentTextWriter = writer as HtmlContentWrapperTextWriter;
-                if (stringCollectionTextWriter != null)
+                if (htmlContentTextWriter != null)
                 {
-                    tagHelperContent.Append(stringCollectionTextWriter.Content);
+                    tagHelperContent.Append(htmlContentTextWriter.ContentBuilder);
                 }
                 else
                 {
@@ -586,7 +602,8 @@ namespace Microsoft.AspNet.Mvc.Razor
             {
                 if (_valueBuffer == null)
                 {
-                    _valueBuffer = new StringCollectionTextWriter(Output.Encoding);
+                    var buffer = new ViewBuffer(BufferScope, Path);
+                    _valueBuffer = new HtmlContentWrapperTextWriter(buffer, Output.Encoding);
                 }
 
                 if (!string.IsNullOrEmpty(prefix))
@@ -604,7 +621,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             {
                 executionContext.AddHtmlAttribute(
                     _tagHelperAttributeInfo.Name,
-                    _valueBuffer?.Content ?? HtmlString.Empty);
+                    (IHtmlContent)_valueBuffer?.ContentBuilder ?? HtmlString.Empty);
                 _valueBuffer = null;
             }
         }

src/Microsoft.AspNet.Mvc.Razor/RazorTextWriter.cs

@@ -7,6 +7,7 @@ using System.Text;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Html;
+using Microsoft.AspNet.Mvc.ViewFeatures;
 
 namespace Microsoft.AspNet.Mvc.Razor
 {

src/Microsoft.AspNet.Mvc.Razor/RazorView.cs

@@ -7,9 +7,9 @@ using System.Diagnostics;
 using System.Linq;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Razor.Buffer;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.AspNet.Mvc.Razor
@@ -23,7 +23,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         private readonly IRazorViewEngine _viewEngine;
         private readonly IRazorPageActivator _pageActivator;
         private readonly HtmlEncoder _htmlEncoder;
-        private IRazorBufferScope _bufferScope;
+        private IViewBufferScope _bufferScope;
 
         /// <summary>
         /// Initializes a new instance of <see cref="RazorView"/>
@@ -97,7 +97,7 @@ namespace Microsoft.AspNet.Mvc.Razor
                 throw new ArgumentNullException(nameof(context));
             }
 
-            _bufferScope = context.HttpContext.RequestServices.GetRequiredService<IRazorBufferScope>();
+            _bufferScope = context.HttpContext.RequestServices.GetRequiredService<IViewBufferScope>();
             var bodyWriter = await RenderPageAsync(RazorPage, context, invokeViewStarts: true);
             await RenderLayoutAsync(context, bodyWriter);
         }
@@ -108,7 +108,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             bool invokeViewStarts)
         {
             Debug.Assert(_bufferScope != null);
-            var buffer = new RazorBuffer(_bufferScope, page.Path);
+            var buffer = new ViewBuffer(_bufferScope, page.Path);
             var razorTextWriter = new RazorTextWriter(context.Writer, buffer, _htmlEncoder);
 
             // The writer for the body is passed through the ViewContext, allowing things like HtmlHelpers

src/Microsoft.AspNet.Mvc.ViewFeatures/Buffer/IViewBufferScope.cs

@@ -0,0 +1,17 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Microsoft.AspNet.Mvc.ViewFeatures.Buffer
+{
+    /// <summary>
+    /// Creates and manages the lifetime of <see cref="ViewBufferValue[]"/> instances.
+    /// </summary>
+    public interface IViewBufferScope
+    {
+        /// <summary>
+        /// Gets a <see cref="ViewBufferValue[]"/>.
+        /// </summary>
+        /// <returns>The <see cref="ViewBufferValue[]"/>.</returns>
+        ViewBufferValue[] GetSegment();
+    }
+}

src/Microsoft.AspNet.Mvc.ViewFeatures/Buffer/MemoryPoolViewBufferScope.cs

@@ -0,0 +1,80 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Buffers;
+using System.Collections.Generic;
+
+namespace Microsoft.AspNet.Mvc.ViewFeatures.Buffer
+{
+    /// <summary>
+    /// A <see cref="IViewBufferScope"/> that uses pooled memory.
+    /// </summary>
+    public class MemoryPoolViewBufferScope : IViewBufferScope, IDisposable
+    {
+        public static readonly int SegmentSize = 512;
+        private readonly ArrayPool<ViewBufferValue> _pool;
+        private List<ViewBufferValue[]> _leased;
+        private bool _disposed;
+
+        /// <summary>
+        /// Initializes a new instance of <see cref="MemoryPoolViewBufferScope"/>.
+        /// </summary>
+        /// <param name="pool">The <see cref="ArrayPool{ViewBufferValue}"/> for creating
+        /// <see cref="ViewBufferValue"/> instances.</param>
+        public MemoryPoolViewBufferScope(ArrayPool<ViewBufferValue> pool)
+        {
+            _pool = pool;
+        }
+
+        /// <inheritdoc />
+        public ViewBufferValue[] GetSegment()
+        {
+            if (_disposed)
+            {
+                throw new ObjectDisposedException(typeof(MemoryPoolViewBufferScope).FullName);
+            }
+
+            if (_leased == null)
+            {
+                _leased = new List<ViewBufferValue[]>(1);
+            }
+
+            ViewBufferValue[] segment = null;
+
+            try
+            {
+                segment = _pool.Rent(SegmentSize);
+                _leased.Add(segment);
+            }
+            catch when (segment != null)
+            {
+                _pool.Return(segment);
+                throw;
+            }
+
+            return segment;
+        }
+
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            if (!_disposed)
+            {
+                _disposed = true;
+
+                if (_leased == null)
+                {
+                    return;
+                }
+
+                for (var i = 0; i < _leased.Count; i++)
+                {
+                    _pool.Return(_leased[i]);
+                }
+
+                _leased.Clear();
+            }
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.ViewFeatures/Buffer/ViewBuffer.cs

@@ -9,23 +9,23 @@ using System.Text.Encodings.Web;
 using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.Rendering;
 
-namespace Microsoft.AspNet.Mvc.Razor.Buffer
+namespace Microsoft.AspNet.Mvc.ViewFeatures.Buffer
 {
     /// <summary>
-    /// An <see cref="IHtmlContentBuilder"/> that is backed by a buffer provided by <see cref="IRazorBufferScope"/>.
+    /// An <see cref="IHtmlContentBuilder"/> that is backed by a buffer provided by <see cref="IViewBufferScope"/>.
     /// </summary>
     [DebuggerDisplay("{DebuggerToString()}")]
-    public class RazorBuffer : IHtmlContentBuilder
+    public class ViewBuffer : IHtmlContentBuilder
     {
-        private readonly IRazorBufferScope _bufferScope;
+        private readonly IViewBufferScope _bufferScope;
         private readonly string _name;
 
         /// <summary>
-        /// Initializes a new instance of <see cref="RazorBuffer"/>.
+        /// Initializes a new instance of <see cref="ViewBuffer"/>.
         /// </summary>
-        /// <param name="bufferScope">The <see cref="IRazorBufferScope"/>.</param>
+        /// <param name="bufferScope">The <see cref="IViewBufferScope"/>.</param>
         /// <param name="name">A name to identify this instance.</param>
-        public RazorBuffer(IRazorBufferScope bufferScope, string name)
+        public ViewBuffer(IViewBufferScope bufferScope, string name)
         {
             if (bufferScope == null)
             {
@@ -39,7 +39,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
         /// <summary>
         /// Gets the backing buffer.
         /// </summary>
-        public IList<RazorBufferSegment> BufferSegments { get; private set; }
+        public IList<ViewBufferValue[]> BufferSegments { get; private set; }
 
         /// <summary>
         /// Gets the count of entries in the last element of <see cref="BufferSegments"/>.
@@ -54,7 +54,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
                 return this;
             }
 
-            AppendValue(new RazorValue(unencoded));
+            AppendValue(new ViewBufferValue(unencoded));
             return this;
         }
 
@@ -66,7 +66,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
                 return this;
             }
 
-            AppendValue(new RazorValue(content));
+            AppendValue(new ViewBufferValue(content));
             return this;
         }
 
@@ -79,23 +79,23 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             }
 
             var value = new HtmlString(encoded);
-            AppendValue(new RazorValue(value));
+            AppendValue(new ViewBufferValue(value));
             return this;
         }
 
-        private void AppendValue(RazorValue value)
+        private void AppendValue(ViewBufferValue value)
         {
-            RazorBufferSegment segment;
+            ViewBufferValue[] segment;
             if (BufferSegments == null)
             {
-                BufferSegments = new List<RazorBufferSegment>(1);
+                BufferSegments = new List<ViewBufferValue[]>(1);
                 segment = _bufferScope.GetSegment();
                 BufferSegments.Add(segment);
             }
             else
             {
                 segment = BufferSegments[BufferSegments.Count - 1];
-                if (CurrentCount == segment.Data.Count)
+                if (CurrentCount == segment.Length)
                 {
                     segment = _bufferScope.GetSegment();
                     BufferSegments.Add(segment);
@@ -103,7 +103,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
                 }
             }
 
-            segment.Data.Array[segment.Data.Offset + CurrentCount] = value;
+            segment[CurrentCount] = value;
             CurrentCount++;
         }
 
@@ -137,11 +137,11 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             for (var i = 0; i < BufferSegments.Count; i++)
             {
                 var segment = BufferSegments[i];
-                var count = i == BufferSegments.Count - 1 ? CurrentCount : segment.Data.Count;
+                var count = i == BufferSegments.Count - 1 ? CurrentCount : segment.Length;
 
                 for (var j = 0; j < count; j++)
                 {
-                    var value = segment.Data.Array[segment.Data.Offset + j];
+                    var value = segment[j];
                     value.WriteTo(writer, encoder);
                 }
             }

src/Microsoft.AspNet.Mvc.ViewFeatures/Buffer/ViewBufferValue.cs

@@ -6,27 +6,27 @@ using System.IO;
 using System.Text.Encodings.Web;
 using Microsoft.AspNet.Html;
 
-namespace Microsoft.AspNet.Mvc.Razor.Buffer
+namespace Microsoft.AspNet.Mvc.ViewFeatures.Buffer
 {
     /// <summary>
     /// Encapsulates a string or <see cref="IHtmlContent"/> value.
     /// </summary>
-    public struct RazorValue
+    public struct ViewBufferValue
     {
         /// <summary>
-        /// Initializes a new instance of <see cref="RazorValue"/> with a <c>string</c> value.
+        /// Initializes a new instance of <see cref="ViewBufferValue"/> with a <c>string</c> value.
         /// </summary>
         /// <param name="value">The value.</param>
-        public RazorValue(string value)
+        public ViewBufferValue(string value)
         {
             Value = value;
         }
 
         /// <summary>
-        /// Initializes a new instance of <see cref="RazorValue"/> with a <see cref="IHtmlContent"/> value.
+        /// Initializes a new instance of <see cref="ViewBufferValue"/> with a <see cref="IHtmlContent"/> value.
         /// </summary>
         /// <param name="value">The <see cref="IHtmlContent"/>.</param>
-        public RazorValue(IHtmlContent content)
+        public ViewBufferValue(IHtmlContent content)
         {
             Value = content;
         }

src/Microsoft.AspNet.Mvc.ViewFeatures/DependencyInjection/MvcViewFeaturesMvcCoreBuilderExtensions.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Buffers;
 using Microsoft.AspNet.Mvc;
 using Microsoft.AspNet.Mvc.Controllers;
 using Microsoft.AspNet.Mvc.Formatters;
@@ -9,8 +10,10 @@ using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewComponents;
 using Microsoft.AspNet.Mvc.ViewEngines;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.MemoryPool;
 using Microsoft.Extensions.OptionsModel;
 
 namespace Microsoft.Extensions.DependencyInjection
@@ -136,6 +139,9 @@ namespace Microsoft.Extensions.DependencyInjection
             // These are stateless so their lifetime isn't really important.
             services.TryAddSingleton<ITempDataDictionaryFactory, TempDataDictionaryFactory>();
             services.TryAddSingleton<SaveTempDataFilter>();
+
+            services.TryAddSingleton(ArrayPool<ViewBufferValue>.Shared);
+            services.TryAddScoped<IViewBufferScope, MemoryPoolViewBufferScope>();
         }
     }
 }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewComponents/DefaultViewComponentHelper.cs

@@ -8,6 +8,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
 
 namespace Microsoft.AspNet.Mvc.ViewComponents
@@ -18,13 +19,15 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
         private readonly HtmlEncoder _htmlEncoder;
         private readonly IViewComponentInvokerFactory _invokerFactory;
         private readonly IViewComponentSelector _selector;
+        private readonly IViewBufferScope _viewBufferScope;
         private ViewContext _viewContext;
 
         public DefaultViewComponentHelper(
             IViewComponentDescriptorCollectionProvider descriptorProvider,
             HtmlEncoder htmlEncoder,
             IViewComponentSelector selector,
-            IViewComponentInvokerFactory invokerFactory)
+            IViewComponentInvokerFactory invokerFactory,
+            IViewBufferScope viewBufferScope)
         {
             if (descriptorProvider == null)
             {
@@ -46,10 +49,16 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
                 throw new ArgumentNullException(nameof(invokerFactory));
             }
 
+            if (viewBufferScope == null)
+            {
+                throw new ArgumentNullException(nameof(viewBufferScope));
+            }
+
             _descriptorProvider = descriptorProvider;
             _htmlEncoder = htmlEncoder;
             _selector = selector;
             _invokerFactory = invokerFactory;
+            _viewBufferScope = viewBufferScope;
         }
 
         public void Contextualize(ViewContext viewContext)
@@ -71,10 +80,11 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
             var descriptor = SelectComponent(name);
 
-            using (var writer = new StringCollectionTextWriter(_viewContext.Writer.Encoding))
+            var viewBuffer = new ViewBuffer(_viewBufferScope, name);
+            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
             {
                 InvokeCore(writer, descriptor, arguments);
-                return writer.Content;
+                return writer.ContentBuilder;
             }
         }
 
@@ -86,11 +96,11 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
             }
 
             var descriptor = SelectComponent(componentType);
-
+            var viewBuffer = new ViewBuffer(_viewBufferScope, componentType.Name);
-            using (var writer = new StringCollectionTextWriter(_viewContext.Writer.Encoding))
+            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
             {
                 InvokeCore(writer, descriptor, arguments);
-                return writer.Content;
+                return writer.ContentBuilder;
             }
         }
 
@@ -125,10 +135,11 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
             var descriptor = SelectComponent(name);
 
-            using (var writer = new StringCollectionTextWriter(_viewContext.Writer.Encoding))
+            var viewBuffer = new ViewBuffer(_viewBufferScope, name);
+            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
             {
                 await InvokeCoreAsync(writer, descriptor, arguments);
-                return writer.Content;
+                return writer.ContentBuilder;
             }
         }
 
@@ -141,10 +152,11 @@ namespace Microsoft.AspNet.Mvc.ViewComponents
 
             var descriptor = SelectComponent(componentType);
 
-            using (var writer = new StringCollectionTextWriter(_viewContext.Writer.Encoding))
+            var viewBuffer = new ViewBuffer(_viewBufferScope, componentType.Name);
+            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
             {
                 await InvokeCoreAsync(writer, descriptor, arguments);
-                return writer.Content;
+                return writer.ContentBuilder;
             }
         }
 

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/DefaultDisplayTemplates.cs

@@ -10,9 +10,9 @@ using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNet.Mvc.ViewFeatures
 {
@@ -124,6 +124,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
                 var fieldNameBase = oldPrefix;
                 var result = new HtmlContentBuilder();
                 var viewEngine = serviceProvider.GetRequiredService<ICompositeViewEngine>();
+                var viewBufferScope = serviceProvider.GetRequiredService<IViewBufferScope>();
 
                 var index = 0;
                 foreach (var item in collection)
@@ -143,6 +144,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
 
                     var templateBuilder = new TemplateBuilder(
                         viewEngine,
+                        viewBufferScope,
                         htmlHelper.ViewContext,
                         htmlHelper.ViewData,
                         modelExplorer,
@@ -223,6 +225,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
 
             var serviceProvider = htmlHelper.ViewContext.HttpContext.RequestServices;
             var viewEngine = serviceProvider.GetRequiredService<ICompositeViewEngine>();
+            var viewBufferScope = serviceProvider.GetRequiredService<IViewBufferScope>();
 
             var content = new HtmlContentBuilder();
             foreach (var propertyExplorer in modelExplorer.Properties)
@@ -235,6 +238,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
 
                 var templateBuilder = new TemplateBuilder(
                     viewEngine,
+                    viewBufferScope,
                     htmlHelper.ViewContext,
                     htmlHelper.ViewData,
                     propertyExplorer,

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/DefaultEditorTemplates.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -87,6 +88,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
                 var fieldNameBase = oldPrefix;
                 var result = new HtmlContentBuilder();
                 var viewEngine = serviceProvider.GetRequiredService<ICompositeViewEngine>();
+                var viewBufferScope = serviceProvider.GetRequiredService<IViewBufferScope>();
 
                 var index = 0;
                 foreach (var item in collection)
@@ -106,6 +108,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
 
                     var templateBuilder = new TemplateBuilder(
                         viewEngine,
+                        viewBufferScope,
                         htmlHelper.ViewContext,
                         htmlHelper.ViewData,
                         modelExplorer,
@@ -245,6 +248,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
 
             var serviceProvider = htmlHelper.ViewContext.HttpContext.RequestServices;
             var viewEngine = serviceProvider.GetRequiredService<ICompositeViewEngine>();
+            var viewBufferScope = serviceProvider.GetRequiredService<IViewBufferScope>();
 
             var content = new HtmlContentBuilder();
             foreach (var propertyExplorer in modelExplorer.Properties)
@@ -257,6 +261,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
 
                 var templateBuilder = new TemplateBuilder(
                     viewEngine,
+                    viewBufferScope,
                     htmlHelper.ViewContext,
                     htmlHelper.ViewData,
                     propertyExplorer,

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/HtmlContentWrapperTextWriter.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.Internal;
 
-namespace Microsoft.AspNet.Mvc.Razor
+namespace Microsoft.AspNet.Mvc.ViewFeatures
 {
     /// <summary>
     /// <see cref="HtmlTextWriter"/> implementation which writes to an <see cref="IHtmlContentBuilder"/> instance.
@@ -20,7 +20,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         /// Initializes a new instance of the <see cref="HtmlContentWrapperTextWriter"/> class.
         /// </summary>
         /// <param name="contentBuilder">The <see cref="IHtmlContentBuilder"/> to write to.</param>
-        /// <param name="encoding">The <see cref="Encoding"/> in which output is written.</param>
+        /// <param name="encoding">The <see cref="System.Text.Encoding"/> in which output is written.</param>
         public HtmlContentWrapperTextWriter(IHtmlContentBuilder contentBuilder, Encoding encoding)
         {
             if (contentBuilder == null)

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/HtmlHelper.cs

@@ -13,6 +13,7 @@ using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.ModelBinding.Validation;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Mvc.ViewFeatures.Internal;
 using Microsoft.Extensions.Internal;
 
@@ -33,6 +34,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         private readonly IHtmlGenerator _htmlGenerator;
         private readonly ICompositeViewEngine _viewEngine;
         private readonly HtmlEncoder _htmlEncoder;
+        private readonly IViewBufferScope _bufferScope;
 
         private ViewContext _viewContext;
 
@@ -43,6 +45,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             IHtmlGenerator htmlGenerator,
             ICompositeViewEngine viewEngine,
             IModelMetadataProvider metadataProvider,
+            IViewBufferScope bufferScope,
             HtmlEncoder htmlEncoder,
             UrlEncoder urlEncoder,
             JavaScriptEncoder javaScriptEncoder)
@@ -62,6 +65,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
                 throw new ArgumentNullException(nameof(metadataProvider));
             }
 
+            if (bufferScope == null)
+            {
+                throw new ArgumentNullException(nameof(bufferScope));
+            }
+
             if (htmlEncoder == null)
             {
                 throw new ArgumentNullException(nameof(htmlEncoder));
@@ -80,6 +88,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             _viewEngine = viewEngine;
             _htmlGenerator = htmlGenerator;
             _htmlEncoder = htmlEncoder;
+            _bufferScope = bufferScope;
             MetadataProvider = metadataProvider;
             UrlEncoder = urlEncoder;
             JavaScriptEncoder = javaScriptEncoder;
@@ -349,10 +358,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         {
             var metadata = ExpressionMetadataProvider.FromStringExpression(expression, ViewData, MetadataProvider);
 
-            return GenerateDisplay(metadata,
+            return GenerateDisplay(
-                                   htmlFieldName ?? ExpressionHelper.GetExpressionText(expression),
+                metadata,
-                                   templateName,
+                htmlFieldName ?? ExpressionHelper.GetExpressionText(expression),
-                                   additionalViewData);
+                templateName,
+                additionalViewData);
         }
 
         /// <inheritdoc />
@@ -493,10 +503,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
                 throw new ArgumentNullException(nameof(partialViewName));
             }
 
-            using (var writer = new StringCollectionTextWriter(Encoding.UTF8))
+            var viewBuffer = new ViewBuffer(_bufferScope, partialViewName);
+            using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, Encoding.UTF8))
             {
                 await RenderPartialCoreAsync(partialViewName, model, viewData, writer);
-                return writer.Content;
+                return writer.ContentBuilder;
             }
         }
 
@@ -519,6 +530,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         {
             var templateBuilder = new TemplateBuilder(
                 _viewEngine,
+                _bufferScope,
                 ViewContext,
                 ViewData,
                 modelExplorer,
@@ -815,6 +827,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
         {
             var templateBuilder = new TemplateBuilder(
                 _viewEngine,
+                _bufferScope,
                 ViewContext,
                 ViewData,
                 modelExplorer,

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/HtmlHelperOfT.cs

@@ -9,6 +9,7 @@ using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 
 namespace Microsoft.AspNet.Mvc.ViewFeatures
 {
@@ -21,35 +22,19 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures
             IHtmlGenerator htmlGenerator,
             ICompositeViewEngine viewEngine,
             IModelMetadataProvider metadataProvider,
+            IViewBufferScope bufferScope,
             HtmlEncoder htmlEncoder,
             UrlEncoder urlEncoder,
             JavaScriptEncoder javaScriptEncoder)
-            : base(htmlGenerator, viewEngine, metadataProvider, htmlEncoder, urlEncoder, javaScriptEncoder)
+            : base(
+                htmlGenerator,
+                viewEngine,
+                metadataProvider,
+                bufferScope,
+                htmlEncoder,
+                urlEncoder,
+                javaScriptEncoder)
         {
-            if (htmlGenerator == null)
-            {
-                throw new ArgumentNullException(nameof(htmlGenerator));
-            }
-            if (viewEngine == null)
-            {
-                throw new ArgumentNullException(nameof(viewEngine));
-            }
-            if (metadataProvider == null)
-            {
-                throw new ArgumentNullException(nameof(metadataProvider));
-            }
-            if (htmlEncoder == null)
-            {
-                throw new ArgumentNullException(nameof(htmlEncoder));
-            }
-            if (urlEncoder == null)
-            {
-                throw new ArgumentNullException(nameof(urlEncoder));
-            }
-            if (javaScriptEncoder == null)
-            {
-                throw new ArgumentNullException(nameof(javaScriptEncoder));
-            }
         }
 
         /// <inheritdoc />

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/StringCollectionTextWriter.cs

@@ -1,260 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO;
-using System.Text;
-using System.Text.Encodings.Web;
-using System.Threading.Tasks;
-using Microsoft.AspNet.Html;
-
-namespace Microsoft.AspNet.Mvc.ViewFeatures
-{
-    /// <summary>
-    /// A <see cref="HtmlTextWriter"/> that stores individual write operations as a sequence of
-    /// <see cref="string"/> and <see cref="IHtmlContent"/> instances.
-    /// </summary>
-    /// <remarks>
-    /// This is primarily designed to avoid creating large in-memory strings.
-    /// Refer to https://aspnetwebstack.codeplex.com/workitem/585 for more details.
-    /// </remarks>
-    public class StringCollectionTextWriter : HtmlTextWriter
-    {
-        private const int MaxCharToStringLength = 1024;
-        private static readonly Task _completedTask = Task.FromResult(0);
-
-        private readonly Encoding _encoding;
-        private readonly StringCollectionTextWriterContent _content;
-
-        /// <summary>
-        /// Creates a new instance of <see cref="StringCollectionTextWriter"/>.
-        /// </summary>
-        /// <param name="encoding">The character <see cref="Encoding"/> in which the output is written.</param>
-        public StringCollectionTextWriter(Encoding encoding)
-        {
-            _encoding = encoding;
-            Entries = new List<object>();
-            _content = new StringCollectionTextWriterContent(Entries);
-        }
-
-        /// <inheritdoc />
-        public override Encoding Encoding
-        {
-            get { return _encoding; }
-        }
-
-        /// <summary>
-        /// Gets the content written to the writer as an <see cref="IHtmlContent"/>.
-        /// </summary>
-        public IHtmlContent Content => _content;
-
-        // internal for testing purposes.
-        internal List<object> Entries { get; }
-
-        /// <inheritdoc />
-        public override void Write(char value)
-        {
-            _content.Append(value.ToString());
-        }
-
-        /// <inheritdoc />
-        public override void Write(char[] buffer, int index, int count)
-        {
-            if (buffer == null)
-            {
-                throw new ArgumentNullException(nameof(buffer));
-            }
-
-            if (index < 0)
-            {
-                throw new ArgumentOutOfRangeException(nameof(index));
-            }
-            if (count < 0 || (buffer.Length - index < count))
-            {
-                throw new ArgumentOutOfRangeException(nameof(count));
-            }
-
-            while (count > 0)
-            {
-                // Split large char arrays into 1KB strings.
-                var currentCount = count;
-                if (MaxCharToStringLength < currentCount)
-                {
-                    currentCount = MaxCharToStringLength;
-                }
-
-                _content.Append(new string(buffer, index, currentCount));
-                index += currentCount;
-                count -= currentCount;
-            }
-        }
-
-        /// <inheritdoc />
-        public override void Write(string value)
-        {
-            if (string.IsNullOrEmpty(value))
-            {
-                return;
-            }
-
-            _content.Append(value);
-        }
-
-        /// <inheritdoc />
-        public override void Write(IHtmlContent value)
-        {
-            _content.Append(value);
-        }
-
-        /// <inheritdoc />
-        public override Task WriteAsync(char value)
-        {
-            Write(value);
-            return _completedTask;
-        }
-
-        /// <inheritdoc />
-        public override Task WriteAsync(char[] buffer, int index, int count)
-        {
-            if (buffer == null)
-            {
-                throw new ArgumentNullException(nameof(buffer));
-            }
-
-            Write(buffer, index, count);
-            return _completedTask;
-        }
-
-        /// <inheritdoc />
-        public override Task WriteAsync(string value)
-        {
-            Write(value);
-            return _completedTask;
-        }
-
-        /// <inheritdoc />
-        public override void WriteLine()
-        {
-            _content.Append(Environment.NewLine);
-        }
-
-        /// <inheritdoc />
-        public override void WriteLine(string value)
-        {
-            Write(value);
-            WriteLine();
-        }
-
-        /// <inheritdoc />
-        public override Task WriteLineAsync(char value)
-        {
-            WriteLine(value);
-            return _completedTask;
-        }
-
-        /// <inheritdoc />
-        public override Task WriteLineAsync(char[] value, int start, int offset)
-        {
-            WriteLine(value, start, offset);
-            return _completedTask;
-        }
-
-        /// <inheritdoc />
-        public override Task WriteLineAsync(string value)
-        {
-            WriteLine(value);
-            return _completedTask;
-        }
-
-        /// <inheritdoc />
-        public override Task WriteLineAsync()
-        {
-            WriteLine();
-            return _completedTask;
-        }
-
-        /// <summary>
-        /// If the specified <paramref name="writer"/> is a <see cref="HtmlTextWriter"/> the contents
-        /// are copied. It is just written to the <paramref name="writer"/> otherwise.
-        /// </summary>
-        /// <param name="writer">The <see cref="TextWriter"/> to which the content must be copied/written.</param>
-        /// <param name="encoder">The <see cref="HtmlEncoder"/> to encode the copied/written content.</param>
-        public void CopyTo(TextWriter writer, HtmlEncoder encoder)
-        {
-            var htmlTextWriter = writer as HtmlTextWriter;
-            if (htmlTextWriter != null)
-            {
-                htmlTextWriter.Write(Content);
-            }
-            else
-            {
-                Content.WriteTo(writer, encoder);
-            }
-        }
-
-        /// <summary>
-        /// If the specified <paramref name="writer"/> is a <see cref="HtmlTextWriter"/> the contents
-        /// are copied. It is just written to the <paramref name="writer"/> otherwise.
-        /// </summary>
-        /// <param name="writer">The <see cref="TextWriter"/> to which the content must be copied/written.</param>
-        /// <param name="encoder">The <see cref="HtmlEncoder"/> to encode the copied/written content.</param>
-        public Task CopyToAsync(TextWriter writer, HtmlEncoder encoder)
-        {
-            CopyTo(writer, encoder);
-            return _completedTask;
-        }
-
-        [DebuggerDisplay("{DebuggerToString()}")]
-        private class StringCollectionTextWriterContent : IHtmlContent
-        {
-            private readonly List<object> _entries;
-
-            public StringCollectionTextWriterContent(List<object> entries)
-            {
-                _entries = entries;
-            }
-
-            public void Append(string value)
-            {
-                _entries.Add(value);
-            }
-
-            public void Append(IHtmlContent content)
-            {
-                _entries.Add(content);
-            }
-
-            public void WriteTo(TextWriter writer, HtmlEncoder encoder)
-            {
-                foreach (var item in _entries)
-                {
-                    if (item == null)
-                    {
-                        continue;
-                    }
-
-                    var itemAsString = item as string;
-                    if (itemAsString != null)
-                    {
-                        writer.Write(itemAsString);
-                    }
-                    else
-                    {
-                        ((IHtmlContent)item).WriteTo(writer, encoder);
-                    }
-                }
-            }
-
-            private string DebuggerToString()
-            {
-                using (var writer = new StringWriter())
-                {
-                    WriteTo(writer, HtmlEncoder.Default);
-                    return writer.ToString();
-                }
-            }
-        }
-    }
-}

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/TemplateBuilder.cs

@@ -7,24 +7,27 @@ using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 
 namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
 {
     public class TemplateBuilder
     {
-        private IViewEngine _viewEngine;
+        private readonly IViewEngine _viewEngine;
-        private ViewContext _viewContext;
+        private readonly IViewBufferScope _bufferScope;
-        private ViewDataDictionary _viewData;
+        private readonly ViewContext _viewContext;
-        private ModelExplorer _modelExplorer;
+        private readonly ViewDataDictionary _viewData;
+        private readonly ModelExplorer _modelExplorer;
         private object _model;
-        private ModelMetadata _metadata;
+        private readonly ModelMetadata _metadata;
-        private string _htmlFieldName;
+        private readonly string _htmlFieldName;
-        private string _templateName;
+        private readonly string _templateName;
-        private bool _readOnly;
+        private readonly bool _readOnly;
-        private object _additionalViewData;
+        private readonly object _additionalViewData;
 
         public TemplateBuilder(
             IViewEngine viewEngine,
+            IViewBufferScope bufferScope,
             ViewContext viewContext,
             ViewDataDictionary viewData,
             ModelExplorer modelExplorer,
@@ -38,6 +41,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
                 throw new ArgumentNullException(nameof(viewEngine));
             }
 
+            if (bufferScope == null)
+            {
+                throw new ArgumentNullException(nameof(_bufferScope));
+            }
+
             if (viewContext == null)
             {
                 throw new ArgumentNullException(nameof(viewContext));
@@ -54,6 +62,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
             }
 
             _viewEngine = viewEngine;
+            _bufferScope = bufferScope;
             _viewContext = viewContext;
             _viewData = viewData;
             _modelExplorer = modelExplorer;
@@ -117,7 +126,13 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
             var visitedObjectsKey = _model ?? _modelExplorer.ModelType;
             viewData.TemplateInfo.AddVisited(visitedObjectsKey);
 
-            var templateRenderer = new TemplateRenderer(_viewEngine, _viewContext, viewData, _templateName, _readOnly);
+            var templateRenderer = new TemplateRenderer(
+                _viewEngine,
+                _bufferScope,
+                _viewContext,
+                viewData,
+                _templateName,
+                _readOnly);
 
             return templateRenderer.Render();
         }

src/Microsoft.AspNet.Mvc.ViewFeatures/ViewFeatures/TemplateRenderer.cs

@@ -11,6 +11,7 @@ using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewEngines;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
@@ -67,14 +68,16 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
                 { IEnumerableOfIFormFileName, DefaultEditorTemplates.FileCollectionInputTemplate },
             };
 
-        private ViewContext _viewContext;
+        private readonly IViewEngine _viewEngine;
-        private ViewDataDictionary _viewData;
+        private readonly IViewBufferScope _bufferScope;
-        private IViewEngine _viewEngine;
+        private readonly ViewContext _viewContext;
-        private string _templateName;
+        private readonly ViewDataDictionary _viewData;
-        private bool _readOnly;
+        private readonly string _templateName;
+        private readonly bool _readOnly;
 
         public TemplateRenderer(
             IViewEngine viewEngine,
+            IViewBufferScope bufferScope,
             ViewContext viewContext,
             ViewDataDictionary viewData,
             string templateName,
@@ -85,6 +88,11 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
                 throw new ArgumentNullException(nameof(viewEngine));
             }
 
+            if (bufferScope == null)
+            {
+                throw new ArgumentNullException(nameof(bufferScope));
+            }
+
             if (viewContext == null)
             {
                 throw new ArgumentNullException(nameof(viewContext));
@@ -96,6 +104,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
             }
 
             _viewEngine = viewEngine;
+            _bufferScope = bufferScope;
             _viewContext = viewContext;
             _viewData = viewData;
             _templateName = templateName;
@@ -118,7 +127,8 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
 
                 if (viewEngineResult.Success)
                 {
-                    using (var writer = new StringCollectionTextWriter(_viewContext.Writer.Encoding))
+                    var viewBuffer = new ViewBuffer(_bufferScope, viewName);
+                    using (var writer = new HtmlContentWrapperTextWriter(viewBuffer, _viewContext.Writer.Encoding))
                     {
                         // Forcing synchronous behavior so users don't have to await templates.
                         var view = viewEngineResult.View;
@@ -127,7 +137,7 @@ namespace Microsoft.AspNet.Mvc.ViewFeatures.Internal
                             var viewContext = new ViewContext(_viewContext, viewEngineResult.View, _viewData, writer);
                             var renderTask = viewEngineResult.View.RenderAsync(viewContext);
                             renderTask.GetAwaiter().GetResult();
-                            return writer.Content;
+                            return writer.ContentBuilder;
                         }
                     }
                 }

src/Microsoft.AspNet.Mvc.ViewFeatures/project.json

@@ -32,7 +32,8 @@
       "version": "1.0.0-*",
       "type": "build"
     },
-    "Microsoft.Extensions.WebEncoders": "1.0.0-*"
+    "Microsoft.Extensions.WebEncoders": "1.0.0-*",
+    "System.Buffers": "4.0.0-*"
   },
   "frameworks": {
     "net451": {},

test/Microsoft.AspNet.Mvc.Localization.Test/Internal/MvcLocalizationServiceCollectionExtensionsTest.cs

@@ -111,6 +111,7 @@ namespace Microsoft.AspNet.Mvc.Localization.Internal
         {
             // Arrange
             var collection = new ServiceCollection();
+            var htmlEncoder = new HtmlTestEncoder();
 
             collection.Configure<RazorViewEngineOptions>(options =>
             {
@@ -123,9 +124,10 @@ namespace Microsoft.AspNet.Mvc.Localization.Internal
                 LanguageViewLocationExpanderFormat.Suffix,
                 setupAction: null);
 
+
             collection.Add(ServiceDescriptor.Transient(typeof(IHtmlLocalizer<>), typeof(TestHtmlLocalizer<>)));
             collection.Add(ServiceDescriptor.Transient(typeof(IHtmlLocalizer), typeof(TestViewLocalizer)));
-            collection.Add(ServiceDescriptor.Singleton(typeof(HtmlEncoder), typeof(HtmlTestEncoder)));
+            collection.Add(ServiceDescriptor.Singleton(typeof(HtmlEncoder), htmlEncoder));
 
             // Assert
             Assert.Collection(collection,
@@ -172,7 +174,7 @@ namespace Microsoft.AspNet.Mvc.Localization.Internal
                 service =>
                 {
                     Assert.Equal(typeof(HtmlEncoder), service.ServiceType);
-                    Assert.Equal(typeof(HtmlTestEncoder), service.ImplementationInstance);
+                    Assert.Same(htmlEncoder, service.ImplementationInstance);
                     Assert.Equal(ServiceLifetime.Singleton, service.Lifetime);
                 });
         }

test/Microsoft.AspNet.Mvc.Razor.Test/RazorPageTest.cs

@@ -5,22 +5,22 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
-using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
 using Microsoft.AspNet.Mvc.ModelBinding;
-using Microsoft.AspNet.Mvc.Razor.Buffer;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.Routing;
 using Microsoft.AspNet.Mvc.TestCommon;
 using Microsoft.AspNet.Mvc.ViewEngines;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Razor.Runtime.TagHelpers;
 using Microsoft.AspNet.Razor.TagHelpers;
 using Microsoft.AspNet.Routing;
 using Microsoft.AspNet.Testing;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.WebEncoders.Testing;
 using Moq;
 using Xunit;
@@ -185,7 +185,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             var page = CreatePage(v =>
             {
                 v.HtmlEncoder = new HtmlTestEncoder();
-                var buffer = new RazorBuffer(new TestRazorBufferScope(), v.Path);
+                var buffer = new ViewBuffer(new TestViewBufferScope(), v.Path);
                 v.StartTagHelperWritingScope(new RazorTextWriter(TextWriter.Null, buffer, v.HtmlEncoder));
                 v.Write("Hello ");
                 v.Write("World!");
@@ -1127,7 +1127,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         public async Task Write_WithHtmlString_WritesValueWithoutEncoding()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), string.Empty);
+            var buffer = new ViewBuffer(new TestViewBufferScope(), string.Empty);
             var writer = new RazorTextWriter(TextWriter.Null, buffer, new HtmlTestEncoder());
 
             var page = CreatePage(p =>
@@ -1177,8 +1177,13 @@ namespace Microsoft.AspNet.Mvc.Razor
         private static ViewContext CreateViewContext(TextWriter writer = null)
         {
             writer = writer ?? new StringWriter();
+            var httpContext = new DefaultHttpContext();
+            var serviceProvider = new ServiceCollection()
+                .AddSingleton<IViewBufferScope, TestViewBufferScope>()
+                .BuildServiceProvider();
+            httpContext.RequestServices = serviceProvider;
             var actionContext = new ActionContext(
-                new DefaultHttpContext(),
+                httpContext,
                 new RouteData(),
                 new ActionDescriptor());
             return new ViewContext(

test/Microsoft.AspNet.Mvc.Razor.Test/RazorTextWriterTest.cs

@@ -7,8 +7,8 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Razor.Buffer;
 using Microsoft.AspNet.Mvc.Rendering;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Testing;
 using Microsoft.Extensions.WebEncoders.Testing;
 using Moq;
@@ -24,7 +24,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         {
             // Arrange
             var expected = new object[] { "True", "3", "18446744073709551615", "Hello world", "3.14", "2.718", "m" };
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(TextWriter.Null, buffer, new HtmlTestEncoder());
 
             // Act
@@ -48,7 +48,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             var expected = new[] { "True", "3", "18446744073709551615", "Hello world", "3.14", "2.718" };
             var unbufferedWriter = new Mock<TextWriter>();
             unbufferedWriter.SetupGet(w => w.Encoding).Returns(Encoding.UTF8);
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(unbufferedWriter.Object, buffer, new HtmlTestEncoder());
             var testClass = new TestClass();
 
@@ -76,7 +76,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             // Arrange
             var unbufferedWriter = new Mock<TextWriter> { CallBase = true };
             unbufferedWriter.SetupGet(w => w.Encoding).Returns(Encoding.UTF8);
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(unbufferedWriter.Object, buffer, new HtmlTestEncoder());
             var buffer1 = new[] { 'a', 'b', 'c', 'd' };
             var buffer2 = new[] { 'd', 'e', 'f' };
@@ -106,7 +106,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             // Arrange
             var unbufferedWriter = new Mock<TextWriter>();
             unbufferedWriter.SetupGet(w => w.Encoding).Returns(Encoding.UTF8);
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(unbufferedWriter.Object, buffer, new HtmlTestEncoder());
 
             // Act
@@ -131,7 +131,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             // Arrange
             var newLine = Environment.NewLine;
             var expected = new List<object> { "False", newLine, "1.1", newLine, "3", newLine };
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(TextWriter.Null, buffer, new HtmlTestEncoder());
 
             // Act
@@ -150,7 +150,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             // Arrange
             var unbufferedWriter = new Mock<TextWriter>();
             unbufferedWriter.SetupGet(w => w.Encoding).Returns(Encoding.UTF8);
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(unbufferedWriter.Object, buffer, new HtmlTestEncoder());
 
             // Act
@@ -172,7 +172,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         {
             // Arrange
             var newLine = Environment.NewLine;
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(TextWriter.Null, buffer, new HtmlTestEncoder());
 
             // Act
@@ -193,7 +193,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             var input2 = "from";
             var input3 = "ASP";
             var input4 = ".Net";
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(TextWriter.Null, buffer, new HtmlTestEncoder());
 
             // Act
@@ -212,7 +212,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
         {
             // Arrange
             var stringWriter = new StringWriter();
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new RazorTextWriter(stringWriter, buffer, new HtmlTestEncoder());
             writer.Flush();
 
@@ -225,10 +225,10 @@ namespace Microsoft.AspNet.Mvc.Razor.Test
             Assert.Equal("Hello, world!", stringWriter.ToString());
         }
 
-        private static object[] GetValues(RazorBuffer buffer)
+        private static object[] GetValues(ViewBuffer buffer)
         {
             return buffer.BufferSegments
-                .SelectMany(c => c.Data)
+                .SelectMany(c => c)
                 .Select(d => d.Value)
                 .TakeWhile(d => d != null)
                 .ToArray();

test/Microsoft.AspNet.Mvc.Razor.Test/RazorViewTest.cs

@@ -9,9 +9,9 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
 using Microsoft.AspNet.Mvc.ModelBinding;
-using Microsoft.AspNet.Mvc.Razor.Buffer;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Primitives;
@@ -1661,7 +1661,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         {
             var httpContext = new DefaultHttpContext();
             var serviceProvider = new ServiceCollection()
-                .AddScoped<IRazorBufferScope, TestRazorBufferScope>()
+                .AddScoped<IViewBufferScope, TestViewBufferScope>()
                 .BuildServiceProvider();
             httpContext.RequestServices = serviceProvider;
             var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());

test/Microsoft.AspNet.Mvc.Razor.Test/TestRazorBufferScope.cs

@@ -1,32 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-
-namespace Microsoft.AspNet.Mvc.Razor.Buffer
-{
-    public class TestRazorBufferScope : IRazorBufferScope
-    {
-        public const int BufferSize = 128;
-        private readonly int _offset;
-        private readonly int _count;
-
-        public TestRazorBufferScope()
-            : this(0, BufferSize)
-        {
-
-        }
-
-        public TestRazorBufferScope(int offset, int count)
-        {
-            _offset = offset;
-            _count = count;
-        }
-
-        public RazorBufferSegment GetSegment()
-        {
-            var razorValues = new RazorValue[BufferSize];
-            return new RazorBufferSegment(new ArraySegment<RazorValue>(razorValues, _offset, _count));
-        }
-    }
-}

test/Microsoft.AspNet.Mvc.Razor.Test/project.json

@@ -6,7 +6,8 @@
   "compile": [
     "../Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileProvider.cs",
     "../Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileInfo.cs",
-    "../Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileTrigger.cs"
+    "../Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileTrigger.cs",
+    "../Microsoft.AspNet.Mvc.ViewFeatures.Test/TestViewBufferScope.cs"
   ],
   "dependencies": {
     "Microsoft.AspNet.Http": "1.0.0-*",

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/Buffer/ViewBufferTest.cs

@@ -5,19 +5,20 @@ using System.IO;
 using System.Linq;
 using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.Rendering;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.Extensions.WebEncoders.Testing;
 using Moq;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.Razor.Buffer
 {
-    public class RazorBufferTest
+    public class ViewBufferTest
     {
         [Fact]
         public void Append_AddsStringRazorValue()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
 
             // Act
             buffer.Append("Hello world");
@@ -25,14 +26,14 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             // Assert
             var segment = Assert.Single(buffer.BufferSegments);
             Assert.Equal(1, buffer.CurrentCount);
-            Assert.Equal("Hello world", segment.Data.Array[0].Value);
+            Assert.Equal("Hello world", segment[0].Value);
         }
 
         [Fact]
         public void Append_AddsHtmlContentRazorValue()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var content = new HtmlString("hello-world");
 
             // Act
@@ -41,14 +42,14 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             // Assert
             var segment = Assert.Single(buffer.BufferSegments);
             Assert.Equal(1, buffer.CurrentCount);
-            Assert.Same(content, segment.Data.Array[0].Value);
+            Assert.Same(content, segment[0].Value);
         }
 
         [Fact]
         public void AppendHtml_AddsHtmlStringValues()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var value = "Hello world";
 
             // Act
@@ -57,7 +58,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             // Assert
             var segment = Assert.Single(buffer.BufferSegments);
             Assert.Equal(1, buffer.CurrentCount);
-            var htmlString = Assert.IsType<HtmlString>(segment.Data.Array[0].Value);
+            var htmlString = Assert.IsType<HtmlString>(segment[0].Value);
             Assert.Equal("Hello world", htmlString.ToString());
         }
 
@@ -65,8 +66,8 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
         public void Append_CreatesNewSegments_WhenCurrentSegmentIsFull()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
-            var expected = Enumerable.Range(0, TestRazorBufferScope.BufferSize).Select(i => i.ToString());
+            var expected = Enumerable.Range(0, TestViewBufferScope.DefaultBufferSize).Select(i => i.ToString());
 
             // Act
             foreach (var item in expected)
@@ -79,51 +80,22 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             // Assert
             Assert.Equal(2, buffer.CurrentCount);
             Assert.Collection(buffer.BufferSegments,
-                segment => Assert.Equal(expected, segment.Data.Array.Select(v => v.Value)),
+                segment => Assert.Equal(expected, segment.Select(v => v.Value)),
                 segment =>
                 {
-                    var array = segment.Data.Array;
+                    var array = segment;
                     Assert.Equal("Hello", array[0].Value);
                     Assert.Equal("world", array[1].Value);
                 });
         }
 
-        [Fact]
-        public void Append_CreatesNewSegments_WhenCurrentSegmentIsFull_ForBuffersWithNonZeroOffsets()
-        {
-            // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(3, 2), "some-name");
-
-            // Act
-            buffer.Append("1");
-            buffer.Append("2");
-            buffer.Append("3");
-            buffer.Append("4");
-
-            // Assert
-            Assert.Equal(2, buffer.CurrentCount);
-            Assert.Collection(buffer.BufferSegments,
-                segment =>
-                {
-                    var array = segment.Data.Array;
-                    Assert.Equal("1", array[3].Value);
-                    Assert.Equal("2", array[4].Value);
-                },
-                segment =>
-                {
-                    var array = segment.Data.Array;
-                    Assert.Equal("3", array[3].Value);
-                    Assert.Equal("4", array[4].Value);
-                });
-        }
-
         [Theory]
         [InlineData(1)]
-        [InlineData(TestRazorBufferScope.BufferSize + 3)]
+        [InlineData(TestViewBufferScope.DefaultBufferSize + 3)]
         public void Clear_ResetsBackingBufferAndIndex(int valuesToWrite)
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
 
             // Act
             for (var i = 0; i < valuesToWrite; i++)
@@ -136,14 +108,14 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
             // Assert
             var segment = Assert.Single(buffer.BufferSegments);
             Assert.Equal(1, buffer.CurrentCount);
-            Assert.Equal("world", segment.Data.Array[0].Value);
+            Assert.Equal("world", segment[0].Value);
         }
 
         [Fact]
         public void WriteTo_WritesSelf_WhenWriterIsHtmlTextWriter()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var htmlWriter = new Mock<HtmlTextWriter>();
             htmlWriter.Setup(w => w.Write(buffer)).Verifiable();
 
@@ -159,7 +131,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
         public void WriteTo_WritesRazorValues_ToTextWriter()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(), "some-name");
             var writer = new StringWriter();
 
             // Act
@@ -180,7 +152,7 @@ namespace Microsoft.AspNet.Mvc.Razor.Buffer
         public void WriteTo_WritesRazorValuesFromAllBuffers(int valuesToWrite)
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(1, 5), "some-name");
+            var buffer = new ViewBuffer(new TestViewBufferScope(4), "some-name");
             var writer = new StringWriter();
             var expected = string.Join("", Enumerable.Range(0, valuesToWrite).Select(_ => "abc"));
 

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/Rendering/DefaultTemplatesUtilities.cs

@@ -18,7 +18,9 @@ using Microsoft.AspNet.Mvc.ModelBinding.Validation;
 using Microsoft.AspNet.Mvc.Routing;
 using Microsoft.AspNet.Mvc.ViewEngines;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Routing;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.OptionsModel;
 using Microsoft.Extensions.WebEncoders.Testing;
 using Moq;
@@ -240,21 +242,6 @@ namespace Microsoft.AspNet.Mvc.Rendering
                 .Setup(f => f.GetUrlHelper(It.IsAny<ActionContext>()))
                 .Returns(urlHelper);
 
-            var serviceProvider = new Mock<IServiceProvider>();
-            serviceProvider
-                .Setup(s => s.GetService(typeof(ICompositeViewEngine)))
-                .Returns(viewEngine);
-            serviceProvider
-                .Setup(s => s.GetService(typeof(IUrlHelperFactory)))
-                .Returns(urlHelperFactory.Object);
-            serviceProvider
-                .Setup(s => s.GetService(typeof(IViewComponentHelper)))
-                .Returns(new Mock<IViewComponentHelper>().Object);
-            serviceProvider
-                .Setup(s => s.GetService(typeof(IViewComponentHelper)))
-                .Returns(new Mock<IViewComponentHelper>().Object);
-
-            httpContext.RequestServices = serviceProvider.Object;
             if (htmlGenerator == null)
             {
                 htmlGenerator = new DefaultHtmlGenerator(
@@ -270,6 +257,7 @@ namespace Microsoft.AspNet.Mvc.Rendering
                 htmlGenerator,
                 viewEngine,
                 provider,
+                new TestViewBufferScope(),
                 new HtmlTestEncoder(),
                 UrlEncoder.Default,
                 JavaScriptEncoder.Default);
@@ -278,14 +266,22 @@ namespace Microsoft.AspNet.Mvc.Rendering
             {
                 innerHelper = innerHelperWrapper(innerHelper);
             }
-            serviceProvider
+
-                .Setup(s => s.GetService(typeof(IHtmlHelper)))
+            var serviceProvider = new ServiceCollection()
-                .Returns(() => innerHelper);
+               .AddSingleton(viewEngine)
+               .AddSingleton(urlHelperFactory.Object)
+               .AddSingleton(Mock.Of<IViewComponentHelper>())
+               .AddSingleton(innerHelper)
+               .AddSingleton<IViewBufferScope, TestViewBufferScope>()
+               .BuildServiceProvider();
+
+            httpContext.RequestServices = serviceProvider;
 
             var htmlHelper = new HtmlHelper<TModel>(
                 htmlGenerator,
                 viewEngine,
                 provider,
+                new TestViewBufferScope(),
                 new HtmlTestEncoder(),
                 UrlEncoder.Default,
                 JavaScriptEncoder.Default);

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/Rendering/HtmlHelperSelectTest.cs

@@ -10,6 +10,7 @@ using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.TestCommon;
 using Microsoft.AspNet.Mvc.ViewEngines;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Testing;
 using Moq;
 using Xunit;
@@ -1567,6 +1568,7 @@ namespace Microsoft.AspNet.Mvc.Rendering
                       new Mock<IHtmlGenerator>(MockBehavior.Strict).Object,
                       new Mock<ICompositeViewEngine>(MockBehavior.Strict).Object,
                       metadataProvider,
+                      new TestViewBufferScope(),
                       new Mock<HtmlEncoder>(MockBehavior.Strict).Object,
                       new Mock<UrlEncoder>(MockBehavior.Strict).Object,
                       new Mock<JavaScriptEncoder>(MockBehavior.Strict).Object)

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/Rendering/ViewContextTests.cs

@@ -3,6 +3,7 @@
 
 using System.IO;
 using System.Text;
+using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.Abstractions;
 using Microsoft.AspNet.Mvc.ModelBinding;
@@ -58,7 +59,7 @@ namespace Microsoft.AspNet.Mvc.Rendering
                 htmlHelperOptions: new HtmlHelperOptions());
             var view = Mock.Of<IView>();
             var viewData = new ViewDataDictionary(originalContext.ViewData);
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
+            var writer = new HtmlContentWrapperTextWriter(new HtmlContentBuilder(), Encoding.UTF8);
 
             // Act
             var context = new ViewContext(originalContext, view, viewData, writer);

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/TestViewBufferScope.cs

@@ -0,0 +1,18 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Microsoft.AspNet.Mvc.ViewFeatures.Buffer
+{
+    public class TestViewBufferScope : IViewBufferScope
+    {
+        public const int DefaultBufferSize = 128;
+        private readonly int _bufferSize;
+
+        public TestViewBufferScope(int bufferSize = DefaultBufferSize)
+        {
+            _bufferSize = bufferSize;
+        }
+
+        public ViewBufferValue[] GetSegment() => new ViewBufferValue[_bufferSize];
+    }
+}

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewComponentResultTest.cs

@@ -16,6 +16,7 @@ using Microsoft.AspNet.Mvc.ModelBinding;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewComponents;
 using Microsoft.AspNet.Mvc.ViewFeatures;
+using Microsoft.AspNet.Mvc.ViewFeatures.Buffer;
 using Microsoft.AspNet.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -482,6 +483,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddSingleton<ITempDataDictionaryFactory, TempDataDictionaryFactory>();
             services.AddSingleton<ITempDataProvider, SessionStateTempDataProvider>();
             services.AddSingleton<HtmlEncoder, HtmlTestEncoder>();
+            services.AddSingleton<IViewBufferScope, TestViewBufferScope>();
 
             return services;
         }

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewFeatures/HtmlContentWrapperTextWriterTest.cs

@@ -2,14 +2,17 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
+using System.Text.Encodings.Web;
 using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Razor.Buffer;
+using Microsoft.AspNet.Html;
 using Microsoft.AspNet.Mvc.Rendering;
 using Xunit;
 
-namespace Microsoft.AspNet.Mvc.Razor
+namespace Microsoft.AspNet.Mvc.ViewFeatures
 {
     public class HtmlContentWrapperTextWriterTest
     {
@@ -20,7 +23,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             var input1 = new ArraySegment<char>(new char[] { 'a', 'b', 'c', 'd' }, 1, 3);
             var input2 = new ArraySegment<char>(new char[] { 'e', 'f' }, 0, 2);
             var input3 = new ArraySegment<char>(new char[] { 'g', 'h', 'i', 'j' }, 3, 1);
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
 
             // Act
@@ -29,12 +32,11 @@ namespace Microsoft.AspNet.Mvc.Razor
             await writer.WriteLineAsync(input3.Array, input3.Offset, input3.Count);
 
             // Assert
-            var bufferValues = GetValues(buffer);
+            Assert.Collection(buffer.Values,
-            Assert.Equal(4, bufferValues.Length);
+                value => Assert.Equal("bcd", value),
-            Assert.Equal("bcd", bufferValues[0]);
+                value => Assert.Equal("ef", value),
-            Assert.Equal("ef", bufferValues[1]);
+                value => Assert.Equal("j", value),
-            Assert.Equal("j", bufferValues[2]);
+                value => Assert.Equal(Environment.NewLine, value));
-            Assert.Equal(Environment.NewLine, bufferValues[3]);
         }
 
         [Fact]
@@ -42,14 +44,15 @@ namespace Microsoft.AspNet.Mvc.Razor
         {
             // Arrange
             var charArray = Enumerable.Range(0, 2050).Select(_ => 'a').ToArray();
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
 
             // Act
             writer.Write(charArray);
 
             // Assert
-            Assert.Collection(GetValues(buffer),
+            Assert.Collection(
+                buffer.Values,
                 value => Assert.Equal(new string('a', 1024), value),
                 value => Assert.Equal(new string('a', 1024), value),
                 value => Assert.Equal("aa", value));
@@ -59,7 +62,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         public void Write_HtmlContent_AddsToEntries()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
             var content = new HtmlString("Hello, world!");
 
@@ -68,7 +71,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             // Assert
             Assert.Collection(
-                GetValues(buffer),
+                buffer.Values,
                 item => Assert.Same(content, item));
         }
 
@@ -76,7 +79,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         public void Write_Object_HtmlContent_AddsToEntries()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
             var content = new HtmlString("Hello, world!");
 
@@ -85,7 +88,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             // Assert
             Assert.Collection(
-                GetValues(buffer),
+                buffer.Values,
                 item => Assert.Same(content, item));
         }
 
@@ -93,7 +96,7 @@ namespace Microsoft.AspNet.Mvc.Razor
         public void WriteLine_Object_HtmlContent_AddsToEntries()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
             var content = new HtmlString("Hello, world!");
 
@@ -102,7 +105,7 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             // Assert
             Assert.Collection(
-                GetValues(buffer),
+                buffer.Values,
                 item => Assert.Same(content, item),
                 item => Assert.Equal(Environment.NewLine, item));
         }
@@ -116,7 +119,7 @@ namespace Microsoft.AspNet.Mvc.Razor
             var input2 = "from";
             var input3 = "ASP";
             var input4 = ".Net";
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
 
             // Act
@@ -126,15 +129,14 @@ namespace Microsoft.AspNet.Mvc.Razor
             await writer.WriteLineAsync(input4);
 
             // Assert
-            var actual = GetValues(buffer);
+            Assert.Equal(new[] { input1, input2, newLine, input3, input4, newLine }, buffer.Values);
-            Assert.Equal(new object[] { input1, input2, newLine, input3, input4, newLine }, actual);
         }
 
         [Fact]
         public void Write_HtmlContent_WritesToBuffer()
         {
             // Arrange
-            var buffer = new RazorBuffer(new TestRazorBufferScope(), "some-name");
+            var buffer = new TestHtmlContentBuilder();
             var writer = new HtmlContentWrapperTextWriter(buffer, Encoding.UTF8);
             var content = new HtmlString("Hello, world!");
 
@@ -143,17 +145,42 @@ namespace Microsoft.AspNet.Mvc.Razor
 
             // Assert
             Assert.Collection(
-                GetValues(buffer),
+                buffer.Values,
                 item => Assert.Same(content, item));
         }
 
-        private static object[] GetValues(RazorBuffer buffer)
+        private class TestHtmlContentBuilder : IHtmlContentBuilder
         {
-            return buffer.BufferSegments
+            public List<object> Values { get; } = new List<object>();
-                .SelectMany(c => c.Data)
+
-                .Select(d => d.Value)
+            public IHtmlContentBuilder Append(string unencoded)
-                .TakeWhile(d => d != null)
+            {
-                .ToArray();
+                Values.Add(unencoded);
+                return this;
+            }
+
+            public IHtmlContentBuilder Append(IHtmlContent content)
+            {
+                Values.Add(content);
+                return this;
+            }
+
+            public IHtmlContentBuilder AppendHtml(string encoded)
+            {
+                Values.Add(new HtmlString(encoded));
+                return this;
+            }
+
+            public IHtmlContentBuilder Clear()
+            {
+                Values.Clear();
+                return this;
+            }
+
+            public void WriteTo(TextWriter writer, HtmlEncoder encoder)
+            {
+                throw new NotSupportedException();
+            }
         }
     }
 }

test/Microsoft.AspNet.Mvc.ViewFeatures.Test/ViewFeatures/StringCollectionTextWriterTest.cs

@@ -1,214 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Text;
-using System.Threading.Tasks;
-using Microsoft.AspNet.Mvc.Rendering;
-using Microsoft.AspNet.Testing;
-using Microsoft.Extensions.Internal;
-using Microsoft.Extensions.WebEncoders.Testing;
-using Xunit;
-
-namespace Microsoft.AspNet.Mvc.ViewFeatures
-{
-    public class StringCollectionTextWriterTest
-    {
-        [Fact]
-        [ReplaceCulture]
-        public void Write_WritesDataTypes_ToBuffer()
-        {
-            // Arrange
-            var expected = new[] { "True", "3", "18446744073709551615", "Hello world", "3.14", "2.718", "m" };
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-
-            // Act
-            writer.Write(true);
-            writer.Write(3);
-            writer.Write(ulong.MaxValue);
-            writer.Write(new TestClass());
-            writer.Write(3.14);
-            writer.Write(2.718m);
-            writer.Write('m');
-
-            // Assert
-            Assert.Equal(expected, writer.Entries);
-        }
-
-        [Fact]
-        [ReplaceCulture]
-        public void WriteLine_WritesDataTypes_ToBuffer()
-        {
-            // Arrange
-            var newLine = Environment.NewLine;
-            var expected = new List<object> { "False", newLine, "1.1", newLine, "3", newLine };
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-
-            // Act
-            writer.WriteLine(false);
-            writer.WriteLine(1.1f);
-            writer.WriteLine(3L);
-
-            // Assert
-            Assert.Equal(expected, writer.Entries);
-        }
-
-        [Fact]
-        public async Task Write_WritesCharBuffer()
-        {
-            // Arrange
-            var input1 = new ArraySegment<char>(new char[] { 'a', 'b', 'c', 'd' }, 1, 3);
-            var input2 = new ArraySegment<char>(new char[] { 'e', 'f' }, 0, 2);
-            var input3 = new ArraySegment<char>(new char[] { 'g', 'h', 'i', 'j' }, 3, 1);
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-
-            // Act
-            writer.Write(input1.Array, input1.Offset, input1.Count);
-            await writer.WriteAsync(input2.Array, input2.Offset, input2.Count);
-            await writer.WriteLineAsync(input3.Array, input3.Offset, input3.Count);
-
-            // Assert
-            var buffer = writer.Entries;
-            Assert.Equal(4, buffer.Count);
-            Assert.Equal("bcd", buffer[0]);
-            Assert.Equal("ef", buffer[1]);
-            Assert.Equal("j", buffer[2]);
-            Assert.Equal(Environment.NewLine, buffer[3]);
-        }
-
-        [Fact]
-        public async Task WriteLines_WritesCharBuffer()
-        {
-            // Arrange
-            var newLine = Environment.NewLine;
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-
-            // Act
-            writer.WriteLine();
-            await writer.WriteLineAsync();
-
-            // Assert
-            var actual = writer.Entries;
-            Assert.Equal<object>(new[] { newLine, newLine }, actual);
-        }
-
-        [Fact]
-        public async Task Write_WritesStringBuffer()
-        {
-            // Arrange
-            var newLine = Environment.NewLine;
-            var input1 = "Hello";
-            var input2 = "from";
-            var input3 = "ASP";
-            var input4 = ".Net";
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-
-            // Act
-            writer.Write(input1);
-            writer.WriteLine(input2);
-            await writer.WriteAsync(input3);
-            await writer.WriteLineAsync(input4);
-
-            // Assert
-            var actual = writer.Entries;
-            Assert.Equal(new[] { input1, input2, newLine, input3, input4, newLine }, actual);
-        }
-
-        [Fact]
-        public void Write_HtmlContent_AddsToEntries()
-        {
-            // Arrange
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-            var content = new HtmlString("Hello, world!");
-
-            // Act
-            writer.Write(content);
-
-            // Assert
-            Assert.Collection(
-                writer.Entries,
-                item => Assert.Same(content, item));
-        }
-
-        [Fact]
-        public void Write_Object_HtmlContent_AddsToEntries()
-        {
-            // Arrange
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-            var content = new HtmlString("Hello, world!");
-
-            // Act
-            writer.Write((object)content);
-
-            // Assert
-            Assert.Collection(
-                writer.Entries,
-                item => Assert.Same(content, item));
-        }
-
-        [Fact]
-        public void WriteLine_Object_HtmlContent_AddsToEntries()
-        {
-            // Arrange
-            var writer = new StringCollectionTextWriter(Encoding.UTF8);
-            var content = new HtmlString("Hello, world!");
-
-            // Act
-            writer.WriteLine(content);
-
-            // Assert
-            Assert.Collection(
-                writer.Entries,
-                item => Assert.Same(content, item),
-                item => Assert.Equal(Environment.NewLine, item));
-        }
-
-        [Fact]
-        public void Copy_CopiesContent_IfTargetTextWriterIsAStringCollectionTextWriter()
-        {
-            // Arrange
-            var source = new StringCollectionTextWriter(Encoding.UTF8);
-            var target = new StringCollectionTextWriter(Encoding.UTF8);
-
-            // Act
-            source.Write("Hello world");
-            source.Write(new char[1], 0, 1);
-            source.CopyTo(target, new HtmlTestEncoder());
-
-            // Assert
-            // Make sure content was written to the source.
-            Assert.Equal(2, source.Entries.Count);
-            Assert.Equal(1, target.Entries.Count);
-
-            var entry = Assert.Single(target.Entries);
-            Assert.Same(source.Content, entry);
-        }
-
-        [Fact]
-        public void Copy_WritesContent_IfTargetTextWriterIsNotAStringCollectionTextWriter()
-        {
-            // Arrange
-            var source = new StringCollectionTextWriter(Encoding.UTF8);
-            var target = new StringWriter();
-            var expected = @"Hello world" + Environment.NewLine + "abc";
-
-            // Act
-            source.WriteLine("Hello world");
-            source.Write(new[] { 'x', 'a', 'b', 'c' }, 1, 3);
-            source.CopyTo(target, new HtmlTestEncoder());
-
-            // Assert
-            Assert.Equal(expected, target.ToString());
-        }
-
-        private class TestClass
-        {
-            public override string ToString()
-            {
-                return "Hello world";
-            }
-        }
-    }
-}