Add SpanStringTokenizer and avoid many string allocations in FontColl…

…ectionBase (#17745) * Create ref struct variant of StringTokenizer and reduce string allocations in FontCollectionBase * Replace constant enum mappings with EnumHelper shim calls --------- Co-authored-by: Max Katz <[email protected]>
AvaloniaUI · Dec 15, 2024 · e991d63 · e991d63
1 parent af11240
commit e991d63
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Showing 24 changed files with 427 additions and 104 deletions.
diff --git a/src/Avalonia.Base/Animation/KeySpline.cs b/src/Avalonia.Base/Animation/KeySpline.cs
@@ -83,7 +83,7 @@ public static KeySpline Parse(string value, CultureInfo? culture)
         {
             culture ??= CultureInfo.InvariantCulture;
 
-            using var tokenizer = new StringTokenizer(value, culture, exceptionMessage: $"Invalid KeySpline string: \"{value}\".");
+            using var tokenizer = new SpanStringTokenizer(value, culture, exceptionMessage: $"Invalid KeySpline string: \"{value}\".");
             return new KeySpline(tokenizer.ReadDouble(), tokenizer.ReadDouble(), tokenizer.ReadDouble(), tokenizer.ReadDouble());
         }
 

diff --git a/src/Avalonia.Base/Animation/Spring.cs b/src/Avalonia.Base/Animation/Spring.cs
@@ -61,7 +61,7 @@ public static Spring Parse(string value, CultureInfo? culture)
             culture = CultureInfo.InvariantCulture;
         }
 
-        using var tokenizer = new StringTokenizer(value, culture, exceptionMessage: $"Invalid Spring string: \"{value}\".");
+        using var tokenizer = new SpanStringTokenizer(value, culture, exceptionMessage: $"Invalid Spring string: \"{value}\".");
         return new Spring(tokenizer.ReadDouble(), tokenizer.ReadDouble(), tokenizer.ReadDouble(), tokenizer.ReadDouble());
     }
 

diff --git a/src/Avalonia.Base/CornerRadius.cs b/src/Avalonia.Base/CornerRadius.cs
@@ -94,7 +94,7 @@ public static CornerRadius Parse(string s)
         {
             const string exceptionMessage = "Invalid CornerRadius.";
 
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage))
             {
                 if (tokenizer.TryReadDouble(out var a))
                 {

diff --git a/src/Avalonia.Base/Matrix.cs b/src/Avalonia.Base/Matrix.cs
@@ -504,7 +504,7 @@ public static Matrix Parse(string s)
             double v8 = 0;
             double v9 = 0;
 
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Matrix."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Matrix."))
             {
                 var v1 = tokenizer.ReadDouble();
                 var v2 = tokenizer.ReadDouble();

diff --git a/src/Avalonia.Base/Media/Fonts/FontCollectionBase.cs b/src/Avalonia.Base/Media/Fonts/FontCollectionBase.cs
@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
+using System.Text;
 using Avalonia.Platform;
 using Avalonia.Utilities;
 
@@ -181,7 +182,7 @@ internal static bool TryFindWeightFallback(
             glyphTypeface = null;
             var weight = (int)key.Weight;
 
-            //If the target weight given is between 400 and 500 inclusive          
+            //If the target weight given is between 400 and 500 inclusive
             if (weight >= 400 && weight <= 500)
             {
                 //Look for available weights between the target and 500, in ascending order.
@@ -212,7 +213,7 @@ internal static bool TryFindWeightFallback(
                 }
             }
 
-            //If a weight less than 400 is given, look for available weights less than the target, in descending order.           
+            //If a weight less than 400 is given, look for available weights less than the target, in descending order.
             if (weight < 400)
             {
                 for (var i = 0; weight - i >= 100; i += 50)
@@ -271,109 +272,54 @@ internal static Typeface GetImplicitTypeface(Typeface typeface, out string norma
             var weight = typeface.Weight;
             var stretch = typeface.Stretch;
 
-            if(TryGetStyle(ref normalizedFamilyName, out var foundStyle))
-            {
-                style = foundStyle;
-            }
-
-            if(TryGetWeight(ref normalizedFamilyName, out var foundWeight))
-            {
-                weight = foundWeight;
-            }
-
-            if(TryGetStretch(ref normalizedFamilyName, out var foundStretch))
-            {
-                stretch = foundStretch;
-            }
-
-            //Preserve old font source
-            return new Typeface(typeface.FontFamily, style, weight, stretch);
-
-        }
-
-        internal static bool TryGetWeight(ref string familyName, out FontWeight weight)
-        {
-            weight = FontWeight.Normal;
+            StringBuilder? normalizedFamilyNameBuilder = null;
+            var totalCharsRemoved = 0;
 
-            var tokenizer = new StringTokenizer(familyName, ' ');
+            var tokenizer = new SpanStringTokenizer(normalizedFamilyName, ' ');
 
+            // Skip initial family name.
             tokenizer.ReadSpan();
 
-            while (tokenizer.TryReadString(out var weightString))
+            while (tokenizer.TryReadSpan(out var token))
             {
-                if (new StringTokenizer(weightString).TryReadInt32(out _))
+                // Don't try to match numbers.
+                if (new SpanStringTokenizer(token).TryReadInt32(out _))
                 {
                     continue;
                 }
 
-                if (!Enum.TryParse(weightString, true, out weight))
-                {
-                    continue;
-                }
-
-                familyName = familyName.Replace(" " + weightString, "").TrimEnd();
-
-                return true;
-            }
-
-            return false;
-        }
-
-        internal static bool TryGetStyle(ref string familyName, out FontStyle style)
-        {
-            style = FontStyle.Normal;
-
-            var tokenizer = new StringTokenizer(familyName, ' ');
-
-            tokenizer.ReadSpan();
-
-            while (tokenizer.TryReadString(out var styleString))
-            {
-                //Do not try to parse an integer
-                if (new StringTokenizer(styleString).TryReadInt32(out _))
+                // Try match with font style, weight or stretch and update accordingly.
+                var match = false;
+                if (EnumHelper.TryParse<FontStyle>(token, true, out var newStyle))
                 {
-                    continue;
+                    style = newStyle;
+                    match = true;
                 }
-
-                if (!Enum.TryParse(styleString, true, out style))
+                else if (EnumHelper.TryParse<FontWeight>(token, true, out var newWeight))
                 {
-                    continue;
+                    weight = newWeight;
+                    match = true;
                 }
-
-                familyName = familyName.Replace(" " + styleString, "").TrimEnd();
-
-                return true;
-            }
-
-            return false;
-        }
-
-        internal static bool TryGetStretch(ref string familyName, out FontStretch stretch)
-        {
-            stretch = FontStretch.Normal;
-
-            var tokenizer = new StringTokenizer(familyName, ' ');
-
-            tokenizer.ReadSpan();
-
-            while (tokenizer.TryReadString(out var stretchString))
-            {
-                if (new StringTokenizer(stretchString).TryReadInt32(out _))
+                else if (EnumHelper.TryParse<FontStretch>(token, true, out var newStretch))
                 {
-                    continue;
+                    stretch = newStretch;
+                    match = true;
                 }
 
-                if (!Enum.TryParse(stretchString, true, out stretch))
+                if (match)
                 {
-                    continue;
+                    // Carve out matched word from the normalized name.
+                    normalizedFamilyNameBuilder ??= new StringBuilder(normalizedFamilyName);
+                    normalizedFamilyNameBuilder.Remove(tokenizer.CurrentTokenIndex - totalCharsRemoved, token.Length);
+                    totalCharsRemoved += token.Length;
                 }
-
-                familyName = familyName.Replace(" " + stretchString, "").TrimEnd();
-
-                return true;
             }
 
-            return false;
+            // Get rid of any trailing spaces.
+            normalizedFamilyName = (normalizedFamilyNameBuilder?.ToString() ?? normalizedFamilyName).TrimEnd();
+
+            //Preserve old font source
+            return new Typeface(typeface.FontFamily, style, weight, stretch);
         }
     }
 }
diff --git a/src/Avalonia.Base/Media/TextDecorationCollection.cs b/src/Avalonia.Base/Media/TextDecorationCollection.cs
@@ -29,7 +29,7 @@ public static TextDecorationCollection Parse(string s)
         {
             var locations = new List<TextDecorationLocation>();
 
-            using (var tokenizer = new StringTokenizer(s, ',', "Invalid text decoration."))
+            using (var tokenizer = new SpanStringTokenizer(s, ',', "Invalid text decoration."))
             {
                 while (tokenizer.TryReadSpan(out var name))
                 {

diff --git a/src/Avalonia.Base/PixelPoint.cs b/src/Avalonia.Base/PixelPoint.cs
@@ -117,7 +117,7 @@ public static implicit operator PixelVector(PixelPoint p)
         /// <returns>The <see cref="PixelPoint"/>.</returns>
         public static PixelPoint Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid PixelPoint."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid PixelPoint."))
             {
                 return new PixelPoint(
                     tokenizer.ReadInt32(),

diff --git a/src/Avalonia.Base/PixelRect.cs b/src/Avalonia.Base/PixelRect.cs
@@ -433,7 +433,7 @@ public override string ToString()
         /// <returns>The parsed <see cref="PixelRect"/>.</returns>
         public static PixelRect Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid PixelRect."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid PixelRect."))
             {
                 return new PixelRect(
                     tokenizer.ReadInt32(),

diff --git a/src/Avalonia.Base/PixelSize.cs b/src/Avalonia.Base/PixelSize.cs
@@ -92,7 +92,7 @@ public static bool TryParse([NotNullWhen(true)] string? source,
             {
                 return false;
             }
-            using (var tokenizer = new StringTokenizer(source, exceptionMessage: "Invalid PixelSize."))
+            using (var tokenizer = new SpanStringTokenizer(source, exceptionMessage: "Invalid PixelSize."))
             {
                 if (tokenizer.TryReadInt32(out var w) && tokenizer.TryReadInt32(out var h))
                 {

diff --git a/src/Avalonia.Base/Point.cs b/src/Avalonia.Base/Point.cs
@@ -184,7 +184,7 @@ public static double Distance(Point value1, Point value2)
         /// <returns>The <see cref="Point"/>.</returns>
         public static Point Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Point."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Point."))
             {
                 return new Point(
                     tokenizer.ReadDouble(),

diff --git a/src/Avalonia.Base/Rect.cs b/src/Avalonia.Base/Rect.cs
@@ -592,7 +592,7 @@ public override string ToString()
         /// <returns>The parsed <see cref="Rect"/>.</returns>
         public static Rect Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Rect."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Rect."))
             {
                 return new Rect(
                     tokenizer.ReadDouble(),

diff --git a/src/Avalonia.Base/RelativePoint.cs b/src/Avalonia.Base/RelativePoint.cs
@@ -169,7 +169,7 @@ public Point ToPixels(Rect rect)
         /// <returns>The parsed <see cref="RelativePoint"/>.</returns>
         public static RelativePoint Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid RelativePoint."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid RelativePoint."))
             {
                 var x = tokenizer.ReadString();
                 var y = tokenizer.ReadString();

diff --git a/src/Avalonia.Base/RelativeRect.cs b/src/Avalonia.Base/RelativeRect.cs
@@ -176,7 +176,7 @@ public Rect ToPixels(Rect boundingBox)
         /// <returns>The parsed <see cref="RelativeRect"/>.</returns>
         public static RelativeRect Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, exceptionMessage: "Invalid RelativeRect."))
+            using (var tokenizer = new SpanStringTokenizer(s, exceptionMessage: "Invalid RelativeRect."))
             {
                 var x = tokenizer.ReadSpan();
                 var y = tokenizer.ReadSpan();

diff --git a/src/Avalonia.Base/Size.cs b/src/Avalonia.Base/Size.cs
@@ -161,7 +161,7 @@ public Size(System.Numerics.Vector2 vector2) : this(vector2.X, vector2.Y)
         /// <returns>The <see cref="Size"/>.</returns>
         public static Size Parse(string s)
         {
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Size."))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage: "Invalid Size."))
             {
                 return new Size(
                     tokenizer.ReadDouble(),

diff --git a/src/Avalonia.Base/Thickness.cs b/src/Avalonia.Base/Thickness.cs
@@ -197,7 +197,7 @@ public static Thickness Parse(string s)
         {
             const string exceptionMessage = "Invalid Thickness.";
 
-            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage))
+            using (var tokenizer = new SpanStringTokenizer(s, CultureInfo.InvariantCulture, exceptionMessage))
             {
                 if (tokenizer.TryReadDouble(out var a))
                 {

diff --git a/src/Avalonia.Base/Utilities/EnumHelper.cs b/src/Avalonia.Base/Utilities/EnumHelper.cs
@@ -9,11 +9,26 @@ public static T Parse<T>(ReadOnlySpan<char> key, bool ignoreCase) where T : stru
         {
             return Enum.Parse<T>(key, ignoreCase);
         }
+
+        public static bool TryParse<T>(ReadOnlySpan<char> key, bool ignoreCase, out T result) where T : struct
+        {
+            return Enum.TryParse(key, ignoreCase, out result);
+        }
 #else
         public static T Parse<T>(string key, bool ignoreCase) where T : struct
         {
             return (T)Enum.Parse(typeof(T), key, ignoreCase);
         }
+
+        public static bool TryParse<T>(string key, bool ignoreCase, out T result) where T : struct
+        {
+            return Enum.TryParse(key, ignoreCase, out result);
+        }
+
+        public static bool TryParse<T>(ReadOnlySpan<char> key, bool ignoreCase, out T result) where T : struct
+        {
+            return Enum.TryParse(key.ToString(), ignoreCase, out result);
+        }
 #endif
     }
 }