performance improvements

Author: DaniilSokolyuk

src/React.AspNet/ActionHtmlString.cs

@@ -11,8 +11,8 @@
 using System.IO;
 
 #if LEGACYASPNET
-using System.Text;
 using System.Web;
+using React.Core;
 #else
 using System.Text.Encodings.Web;
 using IHtmlString = Microsoft.AspNetCore.Html.IHtmlContent;
@@ -41,25 +41,20 @@ public ActionHtmlString(Action<TextWriter> textWriter)
 		}
 
 #if LEGACYASPNET
-		[ThreadStatic]
-		private static StringWriter _sharedStringWriter;
-
 		/// <summary>Returns an HTML-encoded string.</summary>
 		/// <returns>An HTML-encoded string.</returns>
 		public string ToHtmlString()
 		{
-			var stringWriter = _sharedStringWriter;
-			if (stringWriter != null)
+			var pooledWriter = new ReactPooledTextWriter(ReactArrayPool<char>.Instance);
+			try
 			{
-				stringWriter.GetStringBuilder().Clear();
+				_textWriter(pooledWriter);
+				return pooledWriter.ToString();
 			}
-			else
+			finally
 			{
-				_sharedStringWriter = stringWriter = new StringWriter(new StringBuilder(512));
+				pooledWriter.Dispose();
 			}
-
-			_textWriter(stringWriter);
-			return stringWriter.ToString();
 		}
 #else
 		/// <summary>

src/React.Core/ReactArrayPool.cs

@@ -9,7 +9,7 @@
 
 namespace React.Core
 {
-	internal class ReactArrayPool<T> : IArrayPool<T>
+	public class ReactArrayPool<T> : IArrayPool<T>
 	{
 		public static ReactArrayPool<T> Instance = new ReactArrayPool<T>();
 

src/React.Core/ReactComponent.cs

@@ -27,10 +27,7 @@ public class ReactComponent : IReactComponent
 	{
 		private static readonly ConcurrentDictionary<string, bool> _componentNameValidCache = new ConcurrentDictionary<string, bool>();
 
-		[ThreadStatic]
-		private static StringWriter _sharedStringWriter;
-
-		private PagedPooledTextWriter _serializedProps;
+		private ReactPooledTextWriter _serializedProps;
 
 		/// <summary>
 		/// Regular expression used to validate JavaScript identifiers. Used to ensure component
@@ -49,6 +46,10 @@ public class ReactComponent : IReactComponent
 		/// </summary>
 		protected readonly IReactSiteConfiguration _configuration;
 
+		/// <summary>
+		/// Raw props for this component
+		/// </summary>
+		protected object _props;
 
 		/// <summary>
 		/// Gets or sets the name of the component
@@ -75,8 +76,6 @@ public class ReactComponent : IReactComponent
 		/// </summary>
 		public bool ServerOnly { get; set; }
 
-		private object _props;
-
 		/// <summary>
 		/// Gets or sets the props for this component
 		/// </summary>
@@ -117,9 +116,16 @@ public ReactComponent(IReactEnvironment environment, IReactSiteConfiguration con
 		/// <returns>HTML</returns>
 		public string RenderHtml(bool renderContainerOnly = false, bool renderServerOnly = false, Action<Exception, string, string> exceptionHandler = null)
 		{
-			var writer = new StringWriter();
-			RenderHtml(writer, renderContainerOnly, renderServerOnly, exceptionHandler);
-			return writer.ToString();
+			var pooledWriter = new ReactPooledTextWriter(ReactArrayPool<char>.Instance);
+			try
+			{
+				RenderHtml(pooledWriter, renderContainerOnly, renderServerOnly, exceptionHandler);
+				return pooledWriter.ToString();
+			}
+			finally
+			{
+				pooledWriter.Dispose();
+			}
 		}
 
 		/// <summary>
@@ -146,25 +152,14 @@ public virtual void RenderHtml(TextWriter writer, bool renderContainerOnly = fal
 			var html = string.Empty;
 			if (!renderContainerOnly)
 			{
-				var stringWriter = _sharedStringWriter;
-				if (stringWriter != null)
-				{
-					stringWriter.GetStringBuilder().Clear();
-				}
-				else
-				{
-					_sharedStringWriter =
-						stringWriter =
-						new StringWriter(new StringBuilder(512));
-				}
-
+				var pooledWriter = new ReactPooledTextWriter(ReactArrayPool<char>.Instance);
 				try
 				{
-					stringWriter.Write(renderServerOnly ? "ReactDOMServer.renderToStaticMarkup(" : "ReactDOMServer.renderToString(");
-					WriteComponentInitialiser(stringWriter);
-					stringWriter.Write(')');
+					pooledWriter.Write(renderServerOnly ? "ReactDOMServer.renderToStaticMarkup(" : "ReactDOMServer.renderToString(");
+					WriteComponentInitialiser(pooledWriter);
+					pooledWriter.Write(')');
 
-					html = _environment.Execute<string>(stringWriter.ToString());
+					html = _environment.Execute<string>(pooledWriter.ToString());
 
 					if (renderServerOnly)
 					{
@@ -181,6 +176,10 @@ public virtual void RenderHtml(TextWriter writer, bool renderContainerOnly = fal
 
 					exceptionHandler(ex, ComponentName, ContainerId);
 				}
+				finally
+				{
+					pooledWriter.Dispose();
+				}
 			}
 
 			writer.Write('<');
@@ -270,7 +269,7 @@ protected void WriteSerializedProps(TextWriter writer)
 			{
 				var pool = ReactArrayPool<char>.Instance;
 
-				_serializedProps = new PagedPooledTextWriter(pool);
+				_serializedProps = new ReactPooledTextWriter(pool);
 
 				using (var jsonWriter = new JsonTextWriter(_serializedProps))
 				{

src/React.Core/ReactEnvironment.cs

@@ -16,6 +16,7 @@
 using System.Threading;
 using JavaScriptEngineSwitcher.Core;
 using JSPool;
+using React.Core;
 using React.Exceptions;
 using React.TinyIoC;
 
@@ -329,9 +330,16 @@ public virtual IReactComponent CreateComponent(IReactComponent component, bool c
 		/// <returns>JavaScript for all components</returns>
 		public string GetInitJavaScript(bool clientOnly = false)
 		{
-			var writer = new StringWriter();
-			GetInitJavaScript(writer, clientOnly);
-			return writer.ToString();
+			var pooledWriter = new ReactPooledTextWriter(ReactArrayPool<char>.Instance);
+			try
+			{
+				GetInitJavaScript(pooledWriter, clientOnly);
+				return pooledWriter.ToString();
+			}
+			finally
+			{
+				pooledWriter.Dispose();
+			}
 		}
 
 		/// <summary>

src/React.Core/PagedPooledTextWriter.cs renamed to src/React.Core/ReactPooledTextWriter.cs

@@ -6,16 +6,16 @@
 
 namespace React.Core
 {
-	internal class PagedPooledTextWriter : TextWriter
+	public class ReactPooledTextWriter : TextWriter
 	{
 		private readonly IArrayPool<char> _pool;
 
-		public PagedPooledTextWriter(IArrayPool<char> pool)
+		public ReactPooledTextWriter(IArrayPool<char> pool)
 		{
 			_pool = pool;
 		}
 
-		public const int PageSize = 1024;
+		private const int PageSize = 1024;
 
 		private int _charIndex;
 
@@ -69,11 +69,7 @@ public void WriteTo(TextWriter writer)
 			{
 				var page = pages[i];
 				var pageLength = Math.Min(length, page.Length);
-				if (pageLength != 0)
-				{
-					writer.Write(page, index: 0, count: pageLength);
-				}
-
+				writer.Write(page, index: 0, count: pageLength);
 				length -= pageLength;
 			}
 		}
@@ -96,6 +92,40 @@ public override void Write(char[] buffer)
 			Write(buffer, 0, buffer.Length);
 		}
 
+		public override string ToString()
+		{
+			var length = Length;
+
+			if (length == 0)
+			{
+				return string.Empty;
+			}
+
+			char[] sb = _pool.Rent(length);
+
+			int index = 0;
+
+			try
+			{
+				for (var i = 0; i < pages.Count; i++)
+				{
+					var page = pages[i];
+					var pageLength = Math.Min(length, page.Length);
+
+					Array.Copy(page, 0, sb, index, pageLength);
+
+					length -= pageLength;
+					index += pageLength;
+				}
+
+				return new string(sb, 0, index);
+			}
+			finally
+			{
+				_pool.Return(sb);
+			}
+		}
+
 		public override void Write(char[] buffer, int index, int count)
 		{
 			if (buffer == null)
@@ -153,7 +183,7 @@ public override void Write(string value)
 				count -= copyLength;
 			}
 		}
-
+		
 
 		protected override void Dispose(bool disposing)
 		{