Improve AvaloniaObject.GetValue performance (#15342)

* Improve AvaloniaProperty.GetValue performance

* Remove unneeded MethodImpl on Optional.GetValueOrDefault

* Use ReferenceEqualityComparer instead of TypeEqualityComparer

---------

Co-authored-by: Jumar Macato <16554748+jmacato@users.noreply.github.com>

src/Avalonia.Base/AvaloniaObject.cs

@@ -9,8 +9,8 @@ using Avalonia.Data.Core;
 using Avalonia.Diagnostics;
 using Avalonia.Logging;
 using Avalonia.PropertyStore;
-using Avalonia.Reactive;
 using Avalonia.Threading;
+using Avalonia.Utilities;
 
 namespace Avalonia
 {
@@ -126,7 +126,7 @@ namespace Avalonia
         /// <param name="property">The property.</param>
         public void ClearValue(AvaloniaProperty property)
         {
-            _ = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
             _values.ClearValue(property);
         }
@@ -137,7 +137,7 @@ namespace Avalonia
         /// <param name="property">The property.</param>
         public void ClearValue<T>(AvaloniaProperty<T> property)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             switch (property)
@@ -159,7 +159,7 @@ namespace Avalonia
         /// <param name="property">The property.</param>
         public void ClearValue<T>(StyledProperty<T> property)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             _values.ClearValue(property);
@@ -171,11 +171,11 @@ namespace Avalonia
         /// <param name="property">The property.</param>
         public void ClearValue<T>(DirectPropertyBase<T> property)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             var p = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
-            p.InvokeSetter(this, p.GetUnsetValue(GetType()));
+            p.InvokeSetter(this, p.GetUnsetValue(this));
         }
 
         /// <summary>
@@ -216,7 +216,7 @@ namespace Avalonia
         /// <returns>The value.</returns>
         public object? GetValue(AvaloniaProperty property)
         {
-            _ = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
 
             if (property.IsDirect)
                 return property.RouteGetValue(this);
@@ -232,7 +232,7 @@ namespace Avalonia
         /// <returns>The value.</returns>
         public T GetValue<T>(StyledProperty<T> property)
         {
-            _ = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
             return _values.GetValue(property);
         }
@@ -245,7 +245,7 @@ namespace Avalonia
         /// <returns>The value.</returns>
         public T GetValue<T>(DirectPropertyBase<T> property)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             var registered = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
@@ -262,7 +262,7 @@ namespace Avalonia
         /// </remarks>
         public Optional<T> GetBaseValue<T>(StyledProperty<T> property)
         {
-            _ = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
             return _values.GetBaseValue(property);
         }
@@ -274,7 +274,7 @@ namespace Avalonia
         /// <returns>True if the property is animating, otherwise false.</returns>
         public bool IsAnimating(AvaloniaProperty property)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
 
             VerifyAccess();
 
@@ -292,7 +292,7 @@ namespace Avalonia
         /// </remarks>
         public bool IsSet(AvaloniaProperty property)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
 
             VerifyAccess();
 
@@ -310,7 +310,7 @@ namespace Avalonia
             object? value,
             BindingPriority priority = BindingPriority.LocalValue)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
 
             return property.RouteSetValue(this, value, priority);
         }
@@ -330,7 +330,7 @@ namespace Avalonia
             T value,
             BindingPriority priority = BindingPriority.LocalValue)
         {
-            _ = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
             ValidatePriority(priority);
 
@@ -357,7 +357,7 @@ namespace Avalonia
         /// <param name="value">The value.</param>
         public void SetValue<T>(DirectPropertyBase<T> property, T value)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
@@ -401,7 +401,7 @@ namespace Avalonia
         /// </remarks>
         public void SetCurrentValue<T>(StyledProperty<T> property, T value)
         {
-            _ = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             LogPropertySet(property, value, BindingPriority.LocalValue);
@@ -458,8 +458,8 @@ namespace Avalonia
             IObservable<object?> source,
             BindingPriority priority = BindingPriority.LocalValue)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
-            source = source ?? throw new ArgumentNullException(nameof(source));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
+            ThrowHelper.ThrowIfNull(source, nameof(source));
             VerifyAccess();
             ValidatePriority(priority);
 
@@ -495,8 +495,8 @@ namespace Avalonia
             IObservable<T> source,
             BindingPriority priority = BindingPriority.LocalValue)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
-            source = source ?? throw new ArgumentNullException(nameof(source));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
+            ThrowHelper.ThrowIfNull(source, nameof(source));
             VerifyAccess();
             ValidatePriority(priority);
 
@@ -518,8 +518,8 @@ namespace Avalonia
             IObservable<BindingValue<T>> source,
             BindingPriority priority = BindingPriority.LocalValue)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
-            source = source ?? throw new ArgumentNullException(nameof(source));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
+            ThrowHelper.ThrowIfNull(source, nameof(source));
             VerifyAccess();
             ValidatePriority(priority);
 
@@ -539,7 +539,7 @@ namespace Avalonia
             DirectPropertyBase<T> property,
             IObservable<object?> source)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
@@ -574,7 +574,7 @@ namespace Avalonia
             DirectPropertyBase<T> property,
             IObservable<T> source)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
@@ -600,7 +600,7 @@ namespace Avalonia
             DirectPropertyBase<T> property,
             IObservable<BindingValue<T>> source)
         {
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            ThrowHelper.ThrowIfNull(property, nameof(property));
             VerifyAccess();
 
             property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
@@ -796,7 +796,7 @@ namespace Avalonia
         {
             if (value is UnsetValueType)
             {
-                property.InvokeSetter(this, property.GetUnsetValue(GetType()));
+                property.InvokeSetter(this, property.GetUnsetValue(this));
             }
             else if (!(value is DoNothingType))
             {
@@ -815,7 +815,7 @@ namespace Avalonia
             {
                 case BindingValueType.UnsetValue:
                 case BindingValueType.BindingError:
-                    var fallback = value.HasValue ? value : value.WithValue(property.GetUnsetValue(GetType()));
+                    var fallback = value.HasValue ? value : value.WithValue(property.GetUnsetValue(this));
                     property.InvokeSetter(this, fallback);
                     break;
                 case BindingValueType.DataValidationError:
@@ -828,7 +828,7 @@ namespace Avalonia
                     break;
             }
 
-            var metadata = property.GetMetadata(GetType());
+            var metadata = property.GetMetadata(this);
 
             if (metadata.EnableDataValidation == true)
             {

src/Avalonia.Base/AvaloniaProperty.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 using Avalonia.Data;
 using Avalonia.Data.Core;
 using Avalonia.PropertyStore;
@@ -28,10 +29,11 @@ namespace Avalonia
         /// <summary>
         /// Provides a fast path when the property has no metadata overrides.
         /// </summary>
-        private KeyValuePair<Type, AvaloniaPropertyMetadata>? _singleMetadata;
+        private Type? _singleHostType;
+        private AvaloniaPropertyMetadata? _singleMetadata;
 
-        private readonly Dictionary<Type, AvaloniaPropertyMetadata> _metadata;
-        private readonly Dictionary<Type, AvaloniaPropertyMetadata> _metadataCache = new Dictionary<Type, AvaloniaPropertyMetadata>();
+        private readonly Dictionary<Type, AvaloniaPropertyMetadata> _metadata = new(ReferenceEqualityComparer.Instance);
+        private readonly Dictionary<Type, AvaloniaPropertyMetadata> _metadataCache = new(ReferenceEqualityComparer.Instance);
 
         /// <summary>
         /// Initializes a new instance of the <see cref="AvaloniaProperty"/> class.
@@ -60,8 +62,6 @@ namespace Avalonia
                 throw new ArgumentException("'name' may not contain periods.");
             }
 
-            _metadata = new Dictionary<Type, AvaloniaPropertyMetadata>();
-
             Name = name;
             PropertyType = valueType;
             OwnerType = ownerType;
@@ -71,7 +71,8 @@ namespace Avalonia
             metadata.Freeze();
             _metadata.Add(hostType, metadata);
             _defaultMetadata = metadata.GenerateTypeSafeMetadata();
-            _singleMetadata = new(hostType, metadata);
+            _singleHostType = hostType;
+            _singleMetadata = metadata;
         }
 
         /// <summary>
@@ -85,8 +86,6 @@ namespace Avalonia
             Type ownerType,
             AvaloniaPropertyMetadata? metadata)
         {
-            _metadata = new Dictionary<Type, AvaloniaPropertyMetadata>();
-
             Name = source?.Name ?? throw new ArgumentNullException(nameof(source));
             PropertyType = source.PropertyType;
             OwnerType = ownerType ?? throw new ArgumentNullException(nameof(ownerType));
@@ -474,11 +473,39 @@ namespace Avalonia
         /// Gets the <see cref="AvaloniaPropertyMetadata"/> which applies to this property when it is used with the specified type.
         /// </summary>
         /// <typeparam name="T">The type for which to retrieve metadata.</typeparam>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public AvaloniaPropertyMetadata GetMetadata<T>() where T : AvaloniaObject => GetMetadata(typeof(T));
 
         /// <inheritdoc cref="GetMetadata{T}"/>
         /// <param name="type">The type for which to retrieve metadata.</param>
-        public AvaloniaPropertyMetadata GetMetadata(Type type) => GetMetadataWithOverrides(type);
+        /// <remarks>
+        /// For performance, prefer the <see cref="GetMetadata(Avalonia.AvaloniaObject)"/> overload when possible.
+        /// </remarks>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public AvaloniaPropertyMetadata GetMetadata(Type type)
+        {
+            if (_singleMetadata == _defaultMetadata)
+            {
+                return _defaultMetadata;
+            }
+
+            return GetMetadataFromCache(type);
+        }
+
+        /// <summary>
+        /// Gets the <see cref="AvaloniaPropertyMetadata"/> which applies to this property when it is used with the specified object.
+        /// </summary>
+        /// <param name="owner">The object for which to retrieve metadata.</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public AvaloniaPropertyMetadata GetMetadata(AvaloniaObject owner)
+        {
+            if (_singleMetadata == _defaultMetadata)
+            {
+                return _defaultMetadata;
+            }
+
+            return GetMetadataFromCache(owner);
+        }
 
         /// <summary>
         /// Checks whether the <paramref name="value"/> is valid for the property.
@@ -593,42 +620,65 @@ namespace Avalonia
             _metadataCache.Clear();
 
             _singleMetadata = null;
+            _singleHostType = null;
         }
 
         private protected abstract IObservable<AvaloniaPropertyChangedEventArgs> GetChanged();
 
-        private AvaloniaPropertyMetadata GetMetadataWithOverrides(Type type)
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        private AvaloniaPropertyMetadata GetMetadataFromCache(AvaloniaObject obj)
+        {
+            // Don't cache if we have _singleMetadata: IsInstanceOfType is faster than a dictionary lookup.
+            if (_singleMetadata is not null)
+            {
+                return _singleHostType!.IsInstanceOfType(obj) ? _singleMetadata : _defaultMetadata;
+            }
+
+            var type = obj.GetType();
+            if (!_metadataCache.TryGetValue(type, out var result))
+            {
+                _metadataCache[type] = result = GetMetadataUncached(type);
+            }
+
+            return result;
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        private AvaloniaPropertyMetadata GetMetadataFromCache(Type type)
         {
-            if (type is null)
+            if (!_metadataCache.TryGetValue(type, out var result))
             {
-                throw new ArgumentNullException(nameof(type));
+                _metadataCache[type] = result = GetMetadataUncached(type);
             }
 
-            if (_metadataCache.TryGetValue(type, out var result))
+            return result;
+        }
+
+        private AvaloniaPropertyMetadata GetMetadataUncached(Type type)
+        {
+            if (_singleMetadata == _defaultMetadata)
             {
-                return result;
+                return _defaultMetadata;
             }
 
-            if (_singleMetadata is { } singleMetadata)
+            if (_singleMetadata is not null)
             {
-                return _metadataCache[type] = singleMetadata.Key.IsAssignableFrom(type) ? singleMetadata.Value : _defaultMetadata;
+                return _singleHostType!.IsAssignableFrom(type) ? _singleMetadata : _defaultMetadata;
             }
 
             var currentType = type;
 
-            while (currentType != null)
+            while (currentType is not null)
             {
-                if (_metadata.TryGetValue(currentType, out result))
+                if (_metadata.TryGetValue(currentType, out var result))
                 {
-                    _metadataCache[type] = result;
-
                     return result;
                 }
 
                 currentType = currentType.BaseType;
             }
 
-            return _metadataCache[type] = _defaultMetadata;
+            return _defaultMetadata;
         }
 
         bool IPropertyInfo.CanGet => true;

src/Avalonia.Base/AvaloniaPropertyMetadata.cs

@@ -8,7 +8,6 @@ namespace Avalonia
     /// </summary>
     public abstract class AvaloniaPropertyMetadata
     {
-        private bool _isReadOnly;
         private BindingMode _defaultBindingMode;
 
         /// <summary>
@@ -47,6 +46,11 @@ namespace Avalonia
         /// </remarks>
         public bool? EnableDataValidation { get; private set; }
 
+        /// <summary>
+        /// Gets whether this instance is read-only and can't be modified.
+        /// </summary>
+        public bool IsReadOnly { get; private set; }
+
         /// <summary>
         /// Merges the metadata with the base metadata.
         /// </summary>
@@ -56,7 +60,7 @@ namespace Avalonia
             AvaloniaPropertyMetadata baseMetadata, 
             AvaloniaProperty property)
         {
-            if (_isReadOnly)
+            if (IsReadOnly)
             {
                 throw new InvalidOperationException("The metadata is read-only.");
             }
@@ -74,7 +78,7 @@ namespace Avalonia
         /// No further modifications are allowed after this call.
         /// </summary>
         public void Freeze()
-            => _isReadOnly = true;
+            => IsReadOnly = true;
 
         /// <summary>
         /// Gets a copy of this object configured for use with any owner type.

src/Avalonia.Base/Compatibility/ReferenceEqualityComparer.cs

@@ -0,0 +1,22 @@
+#if NETSTANDARD2_0
+
+using System.Runtime.CompilerServices;
+
+namespace System.Collections.Generic;
+
+internal sealed class ReferenceEqualityComparer : IEqualityComparer<object?>, IEqualityComparer
+{
+    public static ReferenceEqualityComparer Instance { get; } = new();
+
+    private ReferenceEqualityComparer()
+    {
+    }
+
+    public new bool Equals(object? x, object? y)
+        => ReferenceEquals(x, y);
+
+    public int GetHashCode(object? obj)
+        => RuntimeHelpers.GetHashCode(obj);
+}
+
+#endif

src/Avalonia.Base/Data/BindingOperations.cs

@@ -34,7 +34,7 @@ namespace Avalonia.Data
 
             if (mode == BindingMode.Default)
             {
-                mode = property.GetMetadata(target.GetType()).DefaultBindingMode;
+                mode = property.GetMetadata(target).DefaultBindingMode;
             }
 
             switch (mode)

src/Avalonia.Base/Data/Core/UntypedBindingExpressionBase.cs

@@ -532,9 +532,9 @@ public abstract class UntypedBindingExpressionBase : BindingExpressionBase,
         if (TargetProperty is not null && _target?.TryGetTarget(out var target) == true)
         {
             if (TargetProperty.IsDirect)
-                _defaultValue = ((IDirectPropertyAccessor)TargetProperty).GetUnsetValue(target.GetType());
+                _defaultValue = ((IDirectPropertyAccessor)TargetProperty).GetUnsetValue(target);
             else
-                _defaultValue = ((IStyledPropertyAccessor)TargetProperty).GetDefaultValue(target.GetType());
+                _defaultValue = ((IStyledPropertyAccessor)TargetProperty).GetDefaultValue(target);
 
             _isDefaultValueInitialized = true;
             return _defaultValue;

src/Avalonia.Base/Data/Optional.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 
 namespace Avalonia.Data
 {
@@ -67,7 +68,7 @@ namespace Avalonia.Data
         /// Gets the value if present, otherwise the default value.
         /// </summary>
         /// <returns>The value.</returns>
-        public T? GetValueOrDefault() => HasValue ? _value : default;
+        public T? GetValueOrDefault() => _value;
 
         /// <summary>
         /// Gets the value if present, otherwise a default value.

src/Avalonia.Base/DirectProperty.cs

@@ -97,7 +97,7 @@ namespace Avalonia
             metadata.Freeze();
 
             var result = new DirectProperty<TNewOwner, TValue>(
-                (DirectPropertyBase<TValue>)this,
+                this,
                 getter,
                 setter,
                 metadata);
@@ -144,9 +144,9 @@ namespace Avalonia
         }
 
         object? IDirectPropertyAccessor.GetUnsetValue(Type type)
-        {
-            var metadata = GetMetadata(type);
-            return metadata.UnsetValue;
-        }
+            => GetMetadata(type).UnsetValue;
+
+        object? IDirectPropertyAccessor.GetUnsetValue(AvaloniaObject owner)
+            => GetMetadata(owner).UnsetValue;
     }
 }

src/Avalonia.Base/DirectPropertyBase.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.CompilerServices;
 using Avalonia.Data;
 using Avalonia.Data.Core;
 using Avalonia.PropertyStore;
@@ -70,21 +71,37 @@ namespace Avalonia
         /// <param name="type">The type.</param>
         /// <returns>The unset value.</returns>
         public TValue GetUnsetValue(Type type)
-        {
-            type = type ?? throw new ArgumentNullException(nameof(type));
-            return GetMetadata(type).UnsetValue;
-        }
+            => GetMetadata(type).UnsetValue;
 
         /// <summary>
-        /// Gets the property metadata for the specified type.
+        /// Gets the unset value for the property on the specified object.
         /// </summary>
-        /// <param name="type">The type.</param>
-        /// <returns>
-        /// The property metadata.
-        /// </returns>
+        /// <param name="owner">The object.</param>
+        /// <returns>The unset value.</returns>
+        public TValue GetUnsetValue(AvaloniaObject owner)
+            => GetMetadata(owner).UnsetValue;
+
+        /// <inheritdoc cref="AvaloniaProperty.GetMetadata(System.Type)"/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public new DirectPropertyMetadata<TValue> GetMetadata(Type type)
+            => CastMetadata(base.GetMetadata(type));
+
+        /// <inheritdoc cref="AvaloniaProperty.GetMetadata(Avalonia.AvaloniaObject)"/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public new DirectPropertyMetadata<TValue> GetMetadata(AvaloniaObject owner)
+            => CastMetadata(base.GetMetadata(owner));
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static DirectPropertyMetadata<TValue> CastMetadata(AvaloniaPropertyMetadata metadata)
         {
-            return (DirectPropertyMetadata<TValue>)base.GetMetadata(type);
+#if DEBUG
+            return (DirectPropertyMetadata<TValue>)metadata;
+#else
+            // Avoid casts in release mode for performance.
+            // We control every path:
+            // it shouldn't be possible a metadata type other than a DirectPropertyMetadata<T> stored for a DirectPropertyBase<T>.
+            return Unsafe.As<DirectPropertyMetadata<TValue>>(metadata);
+#endif
         }
 
         /// <summary>

src/Avalonia.Base/DirectPropertyMetadata`1.cs

@@ -49,6 +49,11 @@ namespace Avalonia
         /// <inheritdoc />
         public override AvaloniaPropertyMetadata GenerateTypeSafeMetadata()
         {
+            if (IsReadOnly)
+            {
+                return this;
+            }
+
             var copy = new DirectPropertyMetadata<TValue>(UnsetValue, DefaultBindingMode, EnableDataValidation);
             copy.Freeze();
             return copy;

src/Avalonia.Base/IDirectPropertyAccessor.cs

@@ -1,5 +1,4 @@
 using System;
-using Avalonia.Metadata;
 
 namespace Avalonia
 {
@@ -38,5 +37,11 @@ namespace Avalonia
         /// </summary>
         /// <param name="type">The type.</param>
         object? GetUnsetValue(Type type);
+
+        /// <summary>
+        /// Gets the unset value of the property for the specified object.
+        /// </summary>
+        /// <param name="owner">The object.</param>
+        object? GetUnsetValue(AvaloniaObject owner);
     }
 }

src/Avalonia.Base/IStyledPropertyAccessor.cs

@@ -16,6 +16,15 @@ namespace Avalonia
         /// </returns>
         object? GetDefaultValue(Type type);
 
+        /// <summary>
+        /// Gets the default value for the property for the specified object.
+        /// </summary>
+        /// <param name="owner">The object.</param>
+        /// <returns>
+        /// The default value.
+        /// </returns>
+        object? GetDefaultValue(AvaloniaObject owner);
+
         /// <summary>
         /// Validates the specified property value.
         /// </summary>

src/Avalonia.Base/PropertyStore/BindingEntryBase.cs

@@ -45,7 +45,7 @@ namespace Avalonia.PropertyStore
             Frame = frame;
             Property = property;
             Source = source;
-            if (property.GetMetadata(target.GetType()).EnableDataValidation == true)
+            if (property.GetMetadata(target).EnableDataValidation == true)
                 _uncommon = new() { _hasDataValidation = true };
         }
 
@@ -112,7 +112,7 @@ namespace Avalonia.PropertyStore
 
         protected abstract BindingValue<TValue> ConvertAndValidate(TSource value);
         protected abstract BindingValue<TValue> ConvertAndValidate(BindingValue<TSource> value);
-        protected abstract TValue GetDefaultValue(Type ownerType);
+        protected abstract TValue GetDefaultValue(AvaloniaObject owner);
 
         protected virtual void Start(bool produceValue)
         {
@@ -186,7 +186,7 @@ namespace Avalonia.PropertyStore
             if (_uncommon?._isDefaultValueInitialized != true)
             {
                 _uncommon ??= new();
-                _uncommon._defaultValue = GetDefaultValue(Frame.Owner!.Owner.GetType());
+                _uncommon._defaultValue = GetDefaultValue(Frame.Owner!.Owner);
                 _uncommon._isDefaultValueInitialized = true;
             }
 

src/Avalonia.Base/PropertyStore/DirectBindingObserver.cs

@@ -15,7 +15,7 @@ namespace Avalonia.PropertyStore
         public DirectBindingObserver(ValueStore owner, DirectPropertyBase<T> property)
         {
             _owner = owner;
-            _hasDataValidation = property.GetMetadata(owner.Owner.GetType())?.EnableDataValidation ?? false;
+            _hasDataValidation = property.GetMetadata(owner.Owner).EnableDataValidation ?? false;
             Property = property;
         }
 

src/Avalonia.Base/PropertyStore/DirectUntypedBindingObserver.cs

@@ -16,7 +16,7 @@ namespace Avalonia.PropertyStore
         public DirectUntypedBindingObserver(ValueStore owner, DirectPropertyBase<T> property)
         {
             _owner = owner;
-            _hasDataValidation = property.GetMetadata(owner.Owner.GetType())?.EnableDataValidation ?? false;
+            _hasDataValidation = property.GetMetadata(owner.Owner).EnableDataValidation ?? false;
             Property = property;
         }
 

src/Avalonia.Base/PropertyStore/EffectiveValue.cs

@@ -11,6 +11,11 @@ namespace Avalonia.PropertyStore
     /// </remarks>
     internal abstract class EffectiveValue
     {
+        /// <summary>
+        /// Gets the property targeted by this value.
+        /// </summary>
+        public AvaloniaProperty Property { get; protected init; }
+
         /// <summary>
         /// Gets the current effective value as a boxed value.
         /// </summary>
@@ -53,6 +58,13 @@ namespace Avalonia.PropertyStore
         /// </summary>
         public bool IsCoercedDefaultValue { get; set; }
 
+        /// <summary>
+        /// Initializes a new instance of <see cref="EffectiveValue"/>.
+        /// </summary>
+        /// <param name="property">The property targeted by this value.</param>
+        protected EffectiveValue(AvaloniaProperty property)
+            => Property = property;
+
         /// <summary>
         /// Begins a reevaluation pass on the effective value.
         /// </summary>

src/Avalonia.Base/PropertyStore/EffectiveValue`1.cs

@@ -23,10 +23,11 @@ namespace Avalonia.PropertyStore
             AvaloniaObject owner,
             StyledProperty<T> property,
             EffectiveValue<T>? inherited)
+            : base(property)
         {
             Priority = BindingPriority.Unset;
             BasePriority = BindingPriority.Unset;
-            _metadata = property.GetMetadata(owner.GetType());
+            _metadata = property.GetMetadata(owner);
 
             var value = inherited is null ? _metadata.DefaultValue : inherited.Value;
 

src/Avalonia.Base/PropertyStore/LocalValueBindingObserverBase.cs

@@ -18,7 +18,7 @@ namespace Avalonia.PropertyStore
         {
             _owner = owner;
             Property = property;
-            _hasDataValidation = property.GetMetadata(owner.Owner.GetType()).EnableDataValidation ?? false;
+            _hasDataValidation = property.GetMetadata(owner.Owner).EnableDataValidation ?? false;
         }
 
         public StyledProperty<T> Property { get;}
@@ -121,7 +121,7 @@ namespace Avalonia.PropertyStore
         {
             if (!_isDefaultValueInitialized)
             {
-                _defaultValue = Property.GetDefaultValue(_owner.Owner.GetType());
+                _defaultValue = Property.GetDefaultValue(_owner.Owner);
                 _isDefaultValueInitialized = true;
             }
 

src/Avalonia.Base/PropertyStore/SourceUntypedBindingEntry.cs

@@ -33,6 +33,6 @@ namespace Avalonia.PropertyStore
             throw new NotSupportedException();
         }
 
-        protected override TTarget GetDefaultValue(Type ownerType) => Property.GetDefaultValue(ownerType);
+        protected override TTarget GetDefaultValue(AvaloniaObject owner) => Property.GetDefaultValue(owner);
     }
 }

src/Avalonia.Base/PropertyStore/TypedBindingEntry.cs

@@ -51,6 +51,6 @@ namespace Avalonia.PropertyStore
             return value;
         }
 
-        protected override T GetDefaultValue(Type ownerType) => Property.GetDefaultValue(ownerType);
+        protected override T GetDefaultValue(AvaloniaObject owner) => Property.GetDefaultValue(owner);
     }
 }

src/Avalonia.Base/PropertyStore/ValueStore.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using Avalonia.Data;
 using Avalonia.Data.Core;
 using Avalonia.Diagnostics;
@@ -283,11 +284,25 @@ namespace Avalonia.PropertyStore
 
         public T GetValue<T>(StyledProperty<T> property)
         {
+            // <!> Performance critical method
             if (_effectiveValues.TryGetValue(property, out var v))
-                return ((EffectiveValue<T>)v).Value;
+                return CastEffectiveValue<T>(v).Value;
             if (property.Inherits && TryGetInheritedValue(property, out v))
-                return ((EffectiveValue<T>)v).Value;
-            return property.GetDefaultValue(Owner.GetType());
+                return CastEffectiveValue<T>(v).Value;
+            return property.GetDefaultValue(Owner);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static EffectiveValue<T> CastEffectiveValue<T>(EffectiveValue value)
+        {
+#if DEBUG
+            return (EffectiveValue<T>)value;
+#else
+            // Avoid casts in release mode for performance since GetValue is a very hot path.
+            // We control every path:
+            // it shouldn't be possible to have something else than an EffectiveValue<T> stored for a T property.
+            return Unsafe.As<EffectiveValue<T>>(value);
+#endif
         }
 
         public bool IsAnimating(AvaloniaProperty property)
@@ -309,7 +324,7 @@ namespace Avalonia.PropertyStore
 
         public void CoerceDefaultValue<T>(StyledProperty<T> property)
         {
-            var metadata = property.GetMetadata(Owner.GetType());
+            var metadata = property.GetMetadata(Owner);
 
             if (metadata.CoerceValue is null)
                 return;
@@ -388,9 +403,9 @@ namespace Avalonia.PropertyStore
 
                 for (var i = 0; i < count; ++i)
                 {
-                    f._effectiveValues.GetKeyValue(i, out var key, out var value);
-                    if (key.Inherits)
-                        values.TryAdd(key, new(value));
+                    var value = f._effectiveValues.GetValue(i);
+                    if (value.Property.Inherits)
+                        values.TryAdd(value.Property, new(value));
                 }
 
                 f = f.InheritanceAncestor;
@@ -405,19 +420,20 @@ namespace Avalonia.PropertyStore
 
                 for (var i = 0; i < count; ++i)
                 {
-                    f._effectiveValues.GetKeyValue(i, out var key, out var value);
+                    var value = f._effectiveValues.GetValue(i);
+                    var property = value.Property;
 
-                    if (!key.Inherits)
+                    if (!property.Inherits)
                         continue;
 
-                    if (values.TryGetValue(key, out var existing))
+                    if (values.TryGetValue(property, out var existing))
                     {
                         if (existing.NewValue is null)
-                            values[key] = existing.WithNewValue(value);
+                            values[property] = existing.WithNewValue(value);
                     }
                     else
                     {
-                        values.Add(key, new(null, value));
+                        values.Add(property, new(null, value));
                     }
                 }
 
@@ -431,12 +447,15 @@ namespace Avalonia.PropertyStore
                 var count = values.Count;
                 for (var i = 0; i < count; ++i)
                 {
-                    values.GetKeyValue(i, out var key, out var v);
+                    var v = values.GetValue(i);
                     var oldValue = v.OldValue;
                     var newValue = v.NewValue;
 
                     if (oldValue != newValue)
-                        InheritedValueChanged(key, oldValue, newValue);
+                    {
+                        var property = v.OldValue?.Property ?? v.NewValue!.Property;
+                        InheritedValueChanged(property, oldValue, newValue);
+                    }
                 }
             }
 
@@ -1077,14 +1096,15 @@ namespace Avalonia.PropertyStore
                 // Remove all effective values that are still unset.
                 for (var i = _effectiveValues.Count - 1; i >= 0; --i)
                 {
-                    _effectiveValues.GetKeyValue(i, out var key, out var e);
+                    var e = _effectiveValues.GetValue(i);
+                    var property = e.Property;
 
-                    e.EndReevaluation(this, key);
+                    e.EndReevaluation(this, property);
 
                     if (e.CanRemove())
                     {
-                        RemoveEffectiveValue(key, i);
-                        e.DisposeAndRaiseUnset(this, key);
+                        RemoveEffectiveValue(property, i);
+                        e.DisposeAndRaiseUnset(this, property);
 
                         if (i > _effectiveValues.Count)
                             break;
@@ -1134,10 +1154,7 @@ namespace Avalonia.PropertyStore
             AvaloniaProperty property,
             [NotNullWhen(true)] out EffectiveValue? value)
         {
-            if (_effectiveValues.TryGetValue(property, out value))
-                return true;
-            value = null;
-            return false;
+            return _effectiveValues.TryGetValue(property, out value);
         }
 
         private EffectiveValue? GetEffectiveValue(AvaloniaProperty property)
@@ -1149,7 +1166,7 @@ namespace Avalonia.PropertyStore
 
         private object? GetDefaultValue(AvaloniaProperty property)
         {
-            return ((IStyledPropertyAccessor)property).GetDefaultValue(Owner.GetType());
+            return ((IStyledPropertyAccessor)property).GetDefaultValue(Owner);
         }
 
         private void DisposeExistingLocalValueBinding(AvaloniaProperty property)

src/Avalonia.Base/StyledProperty.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 using Avalonia.Data;
-using Avalonia.Data.Core;
 using Avalonia.PropertyStore;
 using Avalonia.Utilities;
 
@@ -12,6 +12,10 @@ namespace Avalonia
     /// </summary>
     public class StyledProperty<TValue> : AvaloniaProperty<TValue>, IStyledPropertyAccessor
     {
+        // For performance, cache the default value if there's only one (mostly for AvaloniaObject.GetValue()),
+        // avoiding a GetMetadata() call which might need to iterate through the control hierarchy.
+        private Optional<TValue> _singleDefaultValue;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="StyledProperty{T}"/> class.
         /// </summary>
@@ -41,8 +45,11 @@ namespace Avalonia
             if (validate?.Invoke(metadata.DefaultValue) == false)
             {
                 throw new ArgumentException(
-                    $"'{metadata.DefaultValue}' is not a valid default value for '{name}'.");
+                    $"'{metadata.DefaultValue}' is not a valid default value for '{name}'.",
+                    nameof(metadata));
             }
+
+            _singleDefaultValue = metadata.DefaultValue;
         }
 
         /// <summary>
@@ -68,7 +75,7 @@ namespace Avalonia
 
         public TValue CoerceValue(AvaloniaObject instance, TValue baseValue)
         {
-            var metadata = GetMetadata(instance.GetType());
+            var metadata = GetMetadata(instance);
 
             if (metadata.CoerceValue != null)
             {
@@ -83,22 +90,51 @@ namespace Avalonia
         /// </summary>
         /// <param name="type">The type.</param>
         /// <returns>The default value.</returns>
+        /// <remarks>
+        /// For performance, prefer the <see cref="GetDefaultValue(Avalonia.AvaloniaObject)"/> overload when possible.
+        /// </remarks>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public TValue GetDefaultValue(Type type)
         {
-            return GetMetadata(type).DefaultValue;
+            return _singleDefaultValue.HasValue ?
+                _singleDefaultValue.GetValueOrDefault()! :
+                GetMetadata(type).DefaultValue;
         }
 
         /// <summary>
-        /// Gets the property metadata for the specified type.
+        /// Gets the default value for the property on the specified object.
         /// </summary>
-        /// <param name="type">The type.</param>
-        /// <returns>
-        /// The property metadata.
-        /// </returns>
+        /// <param name="owner">The object.</param>
+        /// <returns>The default value.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public TValue GetDefaultValue(AvaloniaObject owner)
+        {
+            return _singleDefaultValue.HasValue ?
+                _singleDefaultValue.GetValueOrDefault()! :
+                GetMetadata(owner).DefaultValue;
+        }
+
+        /// <inheritdoc cref="AvaloniaProperty.GetMetadata(System.Type)"/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public new StyledPropertyMetadata<TValue> GetMetadata(Type type)
+            => CastMetadata(base.GetMetadata(type));
+
+        /// <inheritdoc cref="AvaloniaProperty.GetMetadata(Avalonia.AvaloniaObject)"/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public new StyledPropertyMetadata<TValue> GetMetadata(AvaloniaObject owner)
+            => CastMetadata(base.GetMetadata(owner));
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static StyledPropertyMetadata<TValue> CastMetadata(AvaloniaPropertyMetadata metadata)
         {
-            _ = type ?? throw new ArgumentNullException(nameof(type));
-            return (StyledPropertyMetadata<TValue>)base.GetMetadata(type);
+#if DEBUG
+            return (StyledPropertyMetadata<TValue>)metadata;
+#else
+            // Avoid casts in release mode for performance (GetMetadata is a hot path).
+            // We control every path:
+            // it shouldn't be possible a metadata type other than a StyledPropertyMetadata<T> stored for a StyledProperty<T>.
+            return Unsafe.As<StyledPropertyMetadata<TValue>>(metadata);
+#endif
         }
 
         /// <summary>
@@ -145,6 +181,11 @@ namespace Avalonia
             }
 
             base.OverrideMetadata(type, metadata);
+
+            if (_singleDefaultValue != metadata.DefaultValue)
+            {
+                _singleDefaultValue = default;
+            }
         }
 
         /// <summary>
@@ -156,8 +197,9 @@ namespace Avalonia
             return Name;
         }
 
-        /// <inheritdoc/>
-        object? IStyledPropertyAccessor.GetDefaultValue(Type type) => GetDefaultBoxedValue(type);
+        object? IStyledPropertyAccessor.GetDefaultValue(Type type) => GetDefaultValue(type);
+
+        object? IStyledPropertyAccessor.GetDefaultValue(AvaloniaObject owner) => GetDefaultValue(owner);
 
         bool IStyledPropertyAccessor.ValidateValue(object? value)
         {
@@ -253,11 +295,5 @@ namespace Avalonia
                 throw new ArgumentException($"Invalid value for Property '{Name}': '{value}' ({type})");
             }
         }
-
-        private object? GetDefaultBoxedValue(Type type)
-        {
-            _ = type ?? throw new ArgumentNullException(nameof(type));
-            return GetMetadata(type).DefaultValue;
-        }
     }
 }

src/Avalonia.Base/StyledPropertyMetadata`1.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.CompilerServices;
 using Avalonia.Data;
 
 namespace Avalonia
@@ -31,7 +32,11 @@ namespace Avalonia
         /// <summary>
         /// Gets the default value for the property.
         /// </summary>
-        public TValue DefaultValue => _defaultValue.GetValueOrDefault()!;
+        public TValue DefaultValue
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _defaultValue.GetValueOrDefault()!;
+        }
 
         /// <summary>
         /// Gets the value coercion callback, if any.
@@ -62,6 +67,11 @@ namespace Avalonia
         /// <inheritdoc />
         public override AvaloniaPropertyMetadata GenerateTypeSafeMetadata()
         {
+            if (IsReadOnly && CoerceValue is null)
+            {
+                return this;
+            }
+
             var copy = new StyledPropertyMetadata<TValue>(DefaultValue, DefaultBindingMode, null, EnableDataValidation ?? false);
             copy.Freeze();
             return copy;

src/Avalonia.Base/Utilities/AvaloniaPropertyDictionary.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 
 namespace Avalonia.Utilities
 {
@@ -52,7 +54,7 @@ namespace Avalonia.Utilities
         /// </summary>
         /// <param name="property">The key to get or set.</param>
         /// <returns>
-        /// The value associated with the specified key. If the key is not found, a get operation 
+        /// The value associated with the specified key. If the key is not found, a get operation
         /// throws a <see cref="KeyNotFoundException"/>, and a set operation creates a
         /// new element for the specified key.
         /// </returns>
@@ -63,16 +65,18 @@ namespace Avalonia.Utilities
         {
             get
             {
-                if (!TryGetEntry(property.Id, out var index))
+                var index = FindEntry(property.Id);
+                if (index < 0)
                     ThrowNotFound();
-                return _entries[index].Value;
+                return UnsafeGetEntryRef(index).Value;
             }
             set
             {
-                if (TryGetEntry(property.Id, out var index))
-                    _entries[index] = new Entry(property, value);
+                var index = FindEntry(property.Id);
+                if (index >= 0)
+                    UnsafeGetEntryRef(index) = new Entry(property, value);
                 else
-                    InsertEntry(new Entry(property, value), index);
+                    InsertEntry(new Entry(property, value), ~index);
             }
         }
 
@@ -88,7 +92,7 @@ namespace Avalonia.Utilities
             {
                 if (index >= _entryCount)
                     ThrowOutOfRange();
-                return _entries![index].Value;
+                return UnsafeGetEntryRef(index).Value;
             }
         }
 
@@ -99,11 +103,12 @@ namespace Avalonia.Utilities
         /// <param name="value">The value of the element to add.</param>
         public void Add(AvaloniaProperty property, TValue value)
         {
-            if (TryGetEntry(property.Id, out var index))
+            var index = FindEntry(property.Id);
+            if (index >= 0)
                 ThrowDuplicate();
-            InsertEntry(new Entry(property, value), index);
+            InsertEntry(new Entry(property, value), ~index);
         }
-        
+
         /// <summary>
         /// Removes all keys and values from the collection.
         /// </summary>
@@ -124,27 +129,19 @@ namespace Avalonia.Utilities
         /// Determines whether the collection contains the specified key.
         /// </summary>
         /// <param name="property">The key.</param>
-        public bool ContainsKey(AvaloniaProperty property) => TryGetEntry(property.Id, out _);
+        public bool ContainsKey(AvaloniaProperty property) => FindEntry(property.Id) >= 0;
 
         /// <summary>
-        /// Gets the key and value at the specified index.
+        /// Gets value at the specified index.
         /// </summary>
-        /// <param name="index">
-        /// The index of the entry, between 0 and <see cref="Count"/> - 1.
-        /// </param>
-        /// <param name="key">
-        /// When this method returns, contains the key at the specified index.
-        /// </param>
-        /// <param name="value">
-        /// When this method returns, contains the value at the specified index.
-        /// </param>
-        public void GetKeyValue(int index, out AvaloniaProperty key, out TValue value)
+        /// <param name="index">The index of the entry, between 0 and <see cref="Count"/> - 1.</param>
+        /// <returns>The value at the specified index.</returns>
+        public TValue GetValue(int index)
         {
             if (index >= _entryCount)
                 ThrowOutOfRange();
-            ref var entry = ref _entries![index];
-            key = entry.Property;
-            value = entry.Value;
+            ref var entry = ref UnsafeGetEntryRef(index);
+            return entry.Value;
         }
 
         /// <summary>
@@ -157,7 +154,8 @@ namespace Avalonia.Utilities
         /// </returns>
         public bool Remove(AvaloniaProperty property)
         {
-            if (TryGetEntry(property.Id, out var index))
+            var index = FindEntry(property.Id);
+            if (index >= 0)
             {
                 RemoveAt(index);
                 return true;
@@ -178,9 +176,10 @@ namespace Avalonia.Utilities
         /// </returns>
         public bool Remove(AvaloniaProperty property, [MaybeNullWhen(false)] out TValue value)
         {
-            if (TryGetEntry(property.Id, out var index))
+            var index = FindEntry(property.Id);
+            if (index >= 0)
             {
-                value = _entries[index].Value;
+                value = UnsafeGetEntryRef(index).Value;
                 RemoveAt(index);
                 return true;
             }
@@ -196,11 +195,11 @@ namespace Avalonia.Utilities
         public void RemoveAt(int index)
         {
             if (_entries is null)
-                throw new IndexOutOfRangeException();
+                ThrowOutOfRange();
 
             Array.Copy(_entries, index + 1, _entries, index, _entryCount - index - 1);
             _entryCount--;
-            _entries[_entryCount] = default;
+            UnsafeGetEntryRef(_entryCount) = default;
         }
 
         /// <summary>
@@ -211,9 +210,10 @@ namespace Avalonia.Utilities
         /// <returns></returns>
         public bool TryAdd(AvaloniaProperty property, TValue value)
         {
-            if (TryGetEntry(property.Id, out var index))
+            var index = FindEntry(property.Id);
+            if (index >= 0)
                 return false;
-            InsertEntry(new Entry(property, value), index);
+            InsertEntry(new Entry(property, value), ~index);
             return true;
         }
 
@@ -228,73 +228,91 @@ namespace Avalonia.Utilities
         /// <returns></returns>
         public bool TryGetValue(AvaloniaProperty property, [MaybeNullWhen(false)] out TValue value)
         {
-            if (TryGetEntry(property.Id, out var index))
+            // <!> Very performance critical code: FindEntry has been manually inlined here.
+            // This gives a ~20% speedup in micro-benchmarks.
+
+            var lo = 0;
+            var hi = _entryCount - 1;
+
+            if (hi >= 0)
             {
-                value = _entries[index].Value;
-                return true;
+                var propertyId = property.Id;
+                ref var entry0 = ref UnsafeGetEntryRef(0);
+
+                do
+                {
+                    // hi and lo are never negative: there's no overflow using unsigned math
+                    var i = (int)(((uint)hi + (uint)lo) >> 1);
+
+#if NET6_0_OR_GREATER
+                    // nuint cast to force zero extend instead of sign extend
+                    ref var entry = ref Unsafe.Add(ref entry0, (nuint)i);
+#else
+                    ref var entry = ref Unsafe.Add(ref entry0, i);
+#endif
+
+                    var entryId = entry.Id;
+                    if (entryId == propertyId)
+                    {
+                        value = entry.Value;
+                        return true;
+                    }
+
+                    if (entryId < propertyId)
+                    {
+                        lo = i + 1;
+                    }
+                    else
+                    {
+                        hi = i - 1;
+                    }
+                } while (lo <= hi);
             }
 
             value = default;
             return false;
         }
 
-        [MemberNotNullWhen(true, nameof(_entries))]
-        private bool TryGetEntry(int propertyId, out int index)
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private int FindEntry(int propertyId)
         {
-            int checkIndex;
-            int iLo = 0;
-            int iHi = _entryCount;
+            var lo = 0;
+            var hi = _entryCount - 1;
 
-            if (iHi <= 0)
+            if (hi >= 0)
             {
-                index = 0;
-                return false;
-            }
+                ref var entry0 = ref UnsafeGetEntryRef(0);
 
-            // Do a binary search to find the value
-            while (iHi - iLo > 3)
-            {
-                int iPv = (iHi + iLo) / 2;
-                checkIndex = _entries![iPv].Property.Id;
-
-                if (propertyId == checkIndex)
+                do
                 {
-                    index = iPv;
-                    return true;
-                }
-
-                if (propertyId <= checkIndex)
-                {
-                    iHi = iPv;
-                }
-                else
-                {
-                    iLo = iPv + 1;
-                }
+                    // hi and lo are never negative: there's no overflow using unsigned math
+                    var i = (int)(((uint)hi + (uint)lo) >> 1);
+
+#if NET6_0_OR_GREATER
+                    // nuint cast to force zero extend instead of sign extend
+                    ref var entry = ref Unsafe.Add(ref entry0, (nuint)i);
+#else
+                    ref var entry = ref Unsafe.Add(ref entry0, i);
+#endif
+
+                    var entryId = entry.Id;
+                    if (entryId == propertyId)
+                    {
+                        return i;
+                    }
+
+                    if (entryId < propertyId)
+                    {
+                        lo = i + 1;
+                    }
+                    else
+                    {
+                        hi = i - 1;
+                    }
+                } while (lo <= hi);
             }
 
-            // Now we only have three values to search; switch to a linear search
-            do
-            {
-                checkIndex = _entries![iLo].Property.Id;
-
-                if (checkIndex == propertyId)
-                {
-                    index = iLo;
-                    return true;
-                }
-
-                if (checkIndex > propertyId)
-                {
-                    // we've gone past the targetIndex - return not found
-                    break;
-                }
-
-                iLo++;
-            } while (iLo < iHi);
-
-            index = iLo;
-            return false;
+            return ~lo;
         }
 
         [MemberNotNull(nameof(_entries))]
@@ -327,18 +345,30 @@ namespace Avalonia.Utilities
                         entryIndex + 1,
                         _entryCount - entryIndex);
 
-                    _entries[entryIndex] = entry;
+                    UnsafeGetEntryRef(entryIndex) = entry;
                 }
             }
             else
             {
                 _entries ??= new Entry[DefaultInitialCapacity];
-                _entries[0] = entry;
+                UnsafeGetEntryRef(0) = entry;
             }
 
             _entryCount++;
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private ref Entry UnsafeGetEntryRef(int index)
+        {
+#if NET6_0_OR_GREATER && !DEBUG
+            // This type is performance critical: in release mode, skip any bound check the JIT compiler couldn't elide.
+            // The index parameter should always be correct when calling this method: no unchecked user input should get here.
+            return ref Unsafe.Add(ref MemoryMarshal.GetArrayDataReference(_entries!), (uint)index);
+#else
+            return ref _entries![index];
+#endif
+        }
+
         [DoesNotReturn]
         private static void ThrowOutOfRange() => throw new IndexOutOfRangeException();
 
@@ -351,12 +381,12 @@ namespace Avalonia.Utilities
 
         private readonly struct Entry
         {
-            public readonly AvaloniaProperty Property;
+            public readonly int Id;
             public readonly TValue Value;
 
             public Entry(AvaloniaProperty property, TValue value)
             {
-                Property = property;
+                Id = property.Id;
                 Value = value;
             }
         }

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindingExtension.cs

@@ -63,7 +63,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
             AvaloniaObject target,
             object? anchor)
         {
-            var enableDataValidation = targetProperty.GetMetadata(target.GetType()).EnableDataValidation ?? false;
+            var enableDataValidation = targetProperty.GetMetadata(target).EnableDataValidation ?? false;
             return InstanceCore(target, targetProperty, anchor, enableDataValidation);
         }
 

src/Markup/Avalonia.Markup/Data/Binding.cs

@@ -77,7 +77,7 @@ namespace Avalonia.Data
             AvaloniaObject target,
             object? anchor)
         {
-            var enableDataValidation = targetProperty.GetMetadata(target.GetType()).EnableDataValidation ?? false;
+            var enableDataValidation = targetProperty.GetMetadata(target).EnableDataValidation ?? false;
             return InstanceCore(targetProperty, target, anchor, enableDataValidation);
         }
 

src/Markup/Avalonia.Markup/Data/BindingBase.cs

@@ -109,7 +109,7 @@ namespace Avalonia.Data
 
             if (mode == BindingMode.Default)
             {
-                if (targetProperty?.GetMetadata(target.GetType()) is { } metadata)
+                if (targetProperty?.GetMetadata(target) is { } metadata)
                     mode = metadata.DefaultBindingMode;
                 else
                     mode = BindingMode.OneWay;

src/Markup/Avalonia.Markup/Data/MultiBinding.cs

@@ -75,7 +75,7 @@ namespace Avalonia.Data
         {
             var input = InstanceCore(target, targetProperty);
             var mode = Mode == BindingMode.Default ?
-                targetProperty?.GetMetadata(target.GetType()).DefaultBindingMode : Mode;
+                targetProperty?.GetMetadata(target).DefaultBindingMode : Mode;
 
             switch (mode)
             {

src/Shared/StringCompatibilityExtensions.cs

@@ -7,7 +7,7 @@ internal static class StringCompatibilityExtensions
 {
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool Contains(this string str, char search) =>
-        str.Contains(search.ToString());
+        str.IndexOf(search) >= 0;
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool EndsWith(this string str, char search) =>

tests/Avalonia.Base.UnitTests/Utilities/AvaloniaPropertyDictionaryTests.cs

@@ -161,7 +161,7 @@ namespace Avalonia.Base.UnitTests.Utilities
 
         [Theory]
         [MemberData(nameof(Counts))]
-        public void GetKeyValue_Finds_Value(int count)
+        public void GetValue_Finds_Value(int count)
         {
             if (count == 0)
                 return;
@@ -169,20 +169,19 @@ namespace Avalonia.Base.UnitTests.Utilities
             var target = CreateTarget(count);
             var index = count / 2;
 
-            target.GetKeyValue(index, out var property, out var value);
+            var value = target.GetValue(index);
 
-            Assert.NotNull(property);
             Assert.NotNull(value);
         }
 
         [Theory]
         [MemberData(nameof(Counts))]
-        public void GetKeyValue_Throws_If_Index_Out_Of_Range(int count)
+        public void GetValue_Throws_If_Index_Out_Of_Range(int count)
         {
             var target = CreateTarget(count);
             var index = count;
 
-            Assert.Throws<IndexOutOfRangeException>(() => target.GetKeyValue(index, out var _, out var _));
+            Assert.Throws<IndexOutOfRangeException>(() => target.GetValue(index));
         }
 
         [Theory]

tests/Avalonia.Benchmarks/ControlHierarchyCreator.cs

@@ -14,7 +14,7 @@ namespace Avalonia.Benchmarks
 
                 for (int j = 0; j < innerCount; ++j)
                 {
-                    var child = new Button();
+                    var child = new Button() { Width = 100, Height = 50 };
 
                     parent.Children.Add(child);