Remove allocations on all base converters, improve TokenizerHelper

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Animation/KeySplineConverter.cs

@@ -1,129 +1,125 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using MS.Internal;
-using System.ComponentModel;
 using System.ComponentModel.Design.Serialization;
+using System.Runtime.CompilerServices;
+using System.Windows.Media.Animation;
+using System.ComponentModel;
 using System.Globalization;
 using System.Reflection;
-using System.Windows.Media.Animation;
+using MS.Internal;
 
 namespace System.Windows
 {
     /// <summary>
-    /// PointConverter - Converter class for converting instances of other types to Point instances
+    /// Converter class for converting instances of <see cref="KeySpline"/> to <see cref="string"/> and vice versa.
     /// </summary>
     /// <ExternalAPI/> 
     public class KeySplineConverter : TypeConverter
     {
         /// <summary>
         /// CanConvertFrom - Returns whether or not this class can convert from a given type
         /// </summary>
-        /// <ExternalAPI/>
+        /// <returns>
+        /// <see langword="true"/> if the given <paramref name="sourceType"/> can be converted from, <see langword="false"/> otherwise.
+        /// </returns>
+        /// <param name="typeDescriptor">The <see cref="ITypeDescriptorContext"/> for this call.</param>
+        /// <param name="destinationType">The <see cref="Type"/> being queried for support.</param>
         public override bool CanConvertFrom(ITypeDescriptorContext typeDescriptor, Type destinationType)
         {
-            if (destinationType == typeof(string))
-            {
-                return true;
-            }
-            else
-            {
-                return false;
-            }
+            return destinationType == typeof(string);
         }
 
         /// <summary>
         /// TypeConverter method override.
         /// </summary>
         /// <param name="context">ITypeDescriptorContext</param>
         /// <param name="destinationType">Type to convert to</param>
-        /// <returns>true if conversion is possible</returns>
-        /// <ExternalAPI/>
+        /// <returns>
+        /// <see langword="true"/> if this class can convert to <paramref name="destinationType"/>, <see langword="false"/> otherwise.
+        /// </returns>
         public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
         {
-            if (   destinationType == typeof(InstanceDescriptor)
-                || destinationType == typeof(string))
-            {
-                return true;
-            }
-            else
-            {
-                return false;
-            }
+            return destinationType == typeof(InstanceDescriptor) || destinationType == typeof(string);
         }
 
         /// <summary>
-        /// ConvertFrom
+        /// Converts <paramref name="value"/> of <see langword="string"/> type to its <see cref="KeySpline"/> represensation.
         /// </summary>
-        public override object ConvertFrom(
-            ITypeDescriptorContext context, 
-            CultureInfo cultureInfo, 
-            object value)
+        /// <param name="context">The <see cref="ITypeDescriptorContext"/> for this call.</param>
+        /// <param name="cultureInfo">The <see cref="CultureInfo"/> which is respected during conversion.</param>
+        /// <param name="value"> The object to convert to a <see cref="KeySpline"/>.</param>
+        /// <returns>A new instance of <see cref="KeySpline"/> class representing the data contained in <paramref name="value"/>.</returns>
+        /// <exception cref="NotSupportedException">Thrown in case the <paramref name="value"/> was not a <see cref="string"/>.</exception>
+        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo cultureInfo, object value)
         {
-            string stringValue = value as string;
-
-            if (value == null)
-            {
+            if (value is not string stringValue)
                 throw new NotSupportedException(SR.Converter_ConvertFromNotSupported);
-            }
 
-            TokenizerHelper th = new TokenizerHelper(stringValue, cultureInfo);
+            ValueTokenizerHelper tokenizer = new(stringValue, cultureInfo);
 
             return new KeySpline(
-                Convert.ToDouble(th.NextTokenRequired(), cultureInfo),
-                Convert.ToDouble(th.NextTokenRequired(), cultureInfo),
-                Convert.ToDouble(th.NextTokenRequired(), cultureInfo),
-                Convert.ToDouble(th.NextTokenRequired(), cultureInfo));
+                double.Parse(tokenizer.NextTokenRequired(), cultureInfo),
+                double.Parse(tokenizer.NextTokenRequired(), cultureInfo),
+                double.Parse(tokenizer.NextTokenRequired(), cultureInfo),
+                double.Parse(tokenizer.NextTokenRequired(), cultureInfo));
         }
 
         /// <summary>
-        /// TypeConverter method implementation.
+        /// Attempt to convert a <see cref="KeySpline"/> class to the <paramref name="destinationType"/>.
         /// </summary>
         /// <param name="context">ITypeDescriptorContext</param>
         /// <param name="cultureInfo">current culture (see CLR specs), null is a valid value</param>
         /// <param name="value">value to convert from</param>
         /// <param name="destinationType">Type to convert to</param>
-        /// <returns>converted value</returns>
-        /// <ExternalAPI/>
-        public override object ConvertTo(
-            ITypeDescriptorContext context, 
-            CultureInfo cultureInfo,
-            object value, 
-            Type destinationType)
+        /// <returns>
+        /// The formatted <paramref name="value"/> as <see cref="string"/> using the specified <paramref name="cultureInfo"/> or an <see cref="InstanceDescriptor"/>.
+        /// </returns>
+        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo cultureInfo, object value, Type destinationType)
         {
-            KeySpline keySpline = value as KeySpline;
-
-            if (keySpline != null && destinationType != null)
+            if (value is KeySpline keySpline && destinationType is not null)
             {
-                if (destinationType == typeof(InstanceDescriptor))
-                {
-                    ConstructorInfo ci = typeof(KeySpline).GetConstructor(new Type[] 
-                        {
-                            typeof(double), typeof(double),
-                            typeof(double), typeof(double) 
-                        });
+                if (destinationType == typeof(string))
+                    return ToString(keySpline, cultureInfo);
 
-                    return new InstanceDescriptor(ci, new object[]
-                        {
-                            keySpline.ControlPoint1.X, keySpline.ControlPoint1.Y,
-                            keySpline.ControlPoint2.X, keySpline.ControlPoint2.Y
-                        });
-                }
-                else if (destinationType == typeof(string))
+                if (destinationType == typeof(InstanceDescriptor))
                 {
-                    return String.Format(
-                        cultureInfo,
-                        "{0}{4}{1}{4}{2}{4}{3}",
-                        keySpline.ControlPoint1.X,
-                        keySpline.ControlPoint1.Y,
-                        keySpline.ControlPoint2.X,
-                        keySpline.ControlPoint2.Y,
-                        cultureInfo != null ? cultureInfo.TextInfo.ListSeparator : CultureInfo.InvariantCulture.TextInfo.ListSeparator);
+                    ConstructorInfo ci = typeof(KeySpline).GetConstructor(new Type[] { typeof(double), typeof(double), typeof(double), typeof(double) });
+                    return new InstanceDescriptor(ci, new object[] { keySpline.ControlPoint1.X, keySpline.ControlPoint1.Y, keySpline.ControlPoint2.X, keySpline.ControlPoint2.Y });
                 }
             }
 
-            // Pass unhandled cases to base class (which will throw exceptions for null value or destinationType.)
+            // Pass unhandled cases to base class (which will throw exceptions for null value or destinationType)
             return base.ConvertTo(context, cultureInfo, value, destinationType);
         }
+
+        /// <summary>
+        /// Converts <paramref name="keySpline"/> to its <see cref="string"/> representation using the specified <paramref name="cultureInfo"/>.
+        /// </summary>
+        /// <param name="keySpline">The <see cref="KeySpline"/> to convert to string.</param>
+        /// <param name="cultureInfo">Culture to use when formatting doubles and choosing separator.</param>
+        /// <returns>The formatted <paramref name="keySpline"/> as <see cref="string"/> using the specified <paramref name="cultureInfo"/>.</returns>
+        private static string ToString(KeySpline keySpline, CultureInfo cultureInfo)
+        {
+            string listSeparator = cultureInfo != null ? cultureInfo.TextInfo.ListSeparator : CultureInfo.InvariantCulture.TextInfo.ListSeparator;
+
+            // Initial capacity [64] is an estimate based on a sum of:
+            // 60 = 4x double (fifteen digits is generous for the range of values)
+            //  3 = 3x separator characters
+            //  1 = 1x scratch space for alignment
+            DefaultInterpolatedStringHandler handler = new(3, 4, cultureInfo, stackalloc char[64]);
+            handler.AppendFormatted(keySpline.ControlPoint1.X);
+            handler.AppendLiteral(listSeparator);
+
+            handler.AppendFormatted(keySpline.ControlPoint1.Y);
+            handler.AppendLiteral(listSeparator);
+
+            handler.AppendFormatted(keySpline.ControlPoint2.X);
+            handler.AppendLiteral(listSeparator);
+
+            handler.AppendFormatted(keySpline.ControlPoint2.Y);
+
+            return handler.ToStringAndClear();
+        }
     }
 }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Generated/DoubleCollection.cs

@@ -713,14 +713,14 @@ public static DoubleCollection Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
             DoubleCollection resource = new DoubleCollection();
 
             double value;
 
-            while (th.NextToken())
+            while (tokenizer.NextToken())
             {
-                value = Convert.ToDouble(th.GetCurrentToken(), formatProvider);
+                value = double.Parse(tokenizer.GetCurrentToken(), formatProvider);
 
                 resource.Add(value);
             }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Generated/GradientStopCollection.cs

@@ -796,16 +796,16 @@ public static GradientStopCollection Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
             GradientStopCollection resource = new GradientStopCollection();
 
             GradientStop value;
 
-            while (th.NextToken())
+            while (tokenizer.NextToken())
             {
                 value = new GradientStop(
-                    Parsers.ParseColor(th.GetCurrentToken(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider));
+                    Parsers.ParseColor(tokenizer.GetCurrentToken().ToString(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider));
 
                 resource.Add(value);
             }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Generated/Int32Collection.cs

@@ -713,14 +713,14 @@ public static Int32Collection Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
             Int32Collection resource = new Int32Collection();
 
             int value;
 
-            while (th.NextToken())
+            while (tokenizer.NextToken())
             {
-                value = Convert.ToInt32(th.GetCurrentToken(), formatProvider);
+                value = Int32.Parse(tokenizer.GetCurrentToken(), formatProvider);
 
                 resource.Add(value);
             }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Generated/PointCollection.cs

@@ -713,16 +713,16 @@ public static PointCollection Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
             PointCollection resource = new PointCollection();
 
             Point value;
 
-            while (th.NextToken())
+            while (tokenizer.NextToken())
             {
                 value = new Point(
-                    Convert.ToDouble(th.GetCurrentToken(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider));
+                    double.Parse(tokenizer.GetCurrentToken(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider));
 
                 resource.Add(value);
             }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Generated/VectorCollection.cs

@@ -713,16 +713,16 @@ public static VectorCollection Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
             VectorCollection resource = new VectorCollection();
 
             Vector value;
 
-            while (th.NextToken())
+            while (tokenizer.NextToken())
             {
                 value = new Vector(
-                    Convert.ToDouble(th.GetCurrentToken(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider));
+                    double.Parse(tokenizer.GetCurrentToken(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider));
 
                 resource.Add(value);
             }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media3D/Generated/Matrix3D.cs

@@ -211,41 +211,41 @@ public static Matrix3D Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
 
             Matrix3D value;
 
-            String firstToken = th.NextTokenRequired();
+            ReadOnlySpan<char> firstToken = tokenizer.NextTokenRequired();
 
             // The token will already have had whitespace trimmed so we can do a
             // simple string compare.
-            if (firstToken == "Identity")
+            if (firstToken.Equals("Identity", StringComparison.Ordinal))
             {
                 value = Identity;
             }
             else
             {
                 value = new Matrix3D(
-                    Convert.ToDouble(firstToken, formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                    Convert.ToDouble(th.NextTokenRequired(), formatProvider));
+                    double.Parse(firstToken, formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                    double.Parse(tokenizer.NextTokenRequired(), formatProvider));
             }
 
             // There should be no more tokens in this string.
-            th.LastTokenRequired();
+            tokenizer.LastTokenRequired();
 
             return value;
         }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media3D/Generated/Point3D.cs

@@ -151,19 +151,19 @@ public static Point3D Parse(string source)
         {
             IFormatProvider formatProvider = System.Windows.Markup.TypeConverterHelper.InvariantEnglishUS;
 
-            TokenizerHelper th = new TokenizerHelper(source, formatProvider);
+            ValueTokenizerHelper tokenizer = new(source, formatProvider);
 
             Point3D value;
 
-            String firstToken = th.NextTokenRequired();
+            ReadOnlySpan<char> firstToken = tokenizer.NextTokenRequired();
 
             value = new Point3D(
-                Convert.ToDouble(firstToken, formatProvider),
-                Convert.ToDouble(th.NextTokenRequired(), formatProvider),
-                Convert.ToDouble(th.NextTokenRequired(), formatProvider));
+                double.Parse(firstToken, formatProvider),
+                double.Parse(tokenizer.NextTokenRequired(), formatProvider),
+                double.Parse(tokenizer.NextTokenRequired(), formatProvider));
 
             // There should be no more tokens in this string.
-            th.LastTokenRequired();
+            tokenizer.LastTokenRequired();
 
             return value;
         }