Use frozen collections

Author: commonsensesoftware

src/AspNetCore/WebApi/src/Asp.Versioning.Http/Http/HttpRequestExtensions.cs

@@ -16,18 +16,20 @@ public static class HttpRequestExtensions
     /// <summary>
     /// Attempts to get the API version from current request path using the provided patterns.
     /// </summary>
+    /// <typeparam name="TList">The type of <see cref="IReadOnlyList{T}">read-only list</see>.</typeparam>
     /// <param name="request">The current <see cref="HttpRequest">HTTP request</see>.</param>
     /// <param name="routePatterns">The <see cref="IReadOnlyList{T}">read-only list</see> of
     /// <see cref="RoutePattern">patterns</see> to evaluate.</param>
     /// <param name="constraintName">The name of the API version route constraint.</param>
     /// <param name="apiVersion">The raw API version, if retrieved.</param>
     /// <returns>True if the raw API version was retrieved; otherwise, false.</returns>
     [EditorBrowsable( EditorBrowsableState.Never )]
-    public static bool TryGetApiVersionFromPath(
+    public static bool TryGetApiVersionFromPath<TList>(
         this HttpRequest request,
-        IReadOnlyList<RoutePattern> routePatterns,
+        TList routePatterns,
         string constraintName,
         [NotNullWhen( true )] out string? apiVersion )
+        where TList : IReadOnlyList<RoutePattern>
     {
         ArgumentNullException.ThrowIfNull( routePatterns );
 

src/AspNetCore/WebApi/src/Asp.Versioning.Http/Routing/ApiVersionMatcherPolicy.cs

@@ -10,6 +10,7 @@ namespace Asp.Versioning.Routing;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using System.Buffers;
+using System.Collections.Frozen;
 using System.Runtime.CompilerServices;
 using System.Text.RegularExpressions;
 using static Asp.Versioning.ApiVersionMapping;
@@ -157,7 +158,7 @@ public PolicyJumpTable BuildJumpTable( int exitDestination, IReadOnlyList<Policy
 
         return new ApiVersionPolicyJumpTable(
             rejection,
-            destinations,
+            destinations.ToFrozenDictionary( destinations.Comparer ),
             NewPolicyFeature( supported, deprecated ),
             routePatterns ?? [],
             apiVersionParser,

src/AspNetCore/WebApi/src/Asp.Versioning.Http/Routing/ApiVersionPolicyJumpTable.cs

@@ -6,6 +6,7 @@ namespace Asp.Versioning.Routing;
 using Microsoft.AspNetCore.Routing.Matching;
 using Microsoft.AspNetCore.Routing.Patterns;
 using Microsoft.Net.Http.Headers;
+using System.Collections.Frozen;
 using System.Runtime.CompilerServices;
 
 internal sealed class ApiVersionPolicyJumpTable : PolicyJumpTable
@@ -14,17 +15,17 @@ internal sealed class ApiVersionPolicyJumpTable : PolicyJumpTable
     private readonly bool versionsByUrlOnly;
     private readonly bool versionsByMediaTypeOnly;
     private readonly RouteDestination rejection;
-    private readonly IReadOnlyDictionary<ApiVersion, int> destinations;
+    private readonly FrozenDictionary<ApiVersion, int> destinations;
     private readonly ApiVersionPolicyFeature? policyFeature;
-    private readonly IReadOnlyList<RoutePattern> routePatterns;
+    private readonly RoutePattern[] routePatterns;
     private readonly IApiVersionParser parser;
     private readonly ApiVersioningOptions options;
 
     internal ApiVersionPolicyJumpTable(
         RouteDestination rejection,
-        IReadOnlyDictionary<ApiVersion, int> destinations,
+        FrozenDictionary<ApiVersion, int> destinations,
         ApiVersionPolicyFeature? policyFeature,
-        IReadOnlyList<RoutePattern> routePatterns,
+        RoutePattern[] routePatterns,
         IApiVersionParser parser,
         IApiVersionParameterSource source,
         ApiVersioningOptions options )
@@ -35,7 +36,7 @@ internal ApiVersionPolicyJumpTable(
         this.routePatterns = routePatterns;
         this.parser = parser;
         this.options = options;
-        versionsByUrl = routePatterns.Count > 0;
+        versionsByUrl = routePatterns.Length > 0;
         versionsByUrlOnly = source.VersionsByUrl( allowMultipleLocations: false );
         versionsByMediaTypeOnly = source.VersionsByMediaType( allowMultipleLocations: false );
     }

src/Common/src/Common/MediaTypeApiVersionReaderBuilder.cs

@@ -18,13 +18,16 @@ namespace Asp.Versioning;
 
 #if !NETFRAMEWORK
 using System.Buffers;
+using System.Collections.Frozen;
 #endif
 using System.Runtime.CompilerServices;
 using System.Text.RegularExpressions;
 #if NETFRAMEWORK
-using Str = System.String;
+using FrozenSet = System.Collections.Generic.HashSet<System.String>;
+using Str = string;
 using StrComparer = System.StringComparer;
 #else
+using FrozenSet = System.Collections.Frozen.FrozenSet<Microsoft.Extensions.Primitives.StringSegment>;
 using Str = Microsoft.Extensions.Primitives.StringSegment;
 using StrComparer = Microsoft.Extensions.Primitives.StringSegmentComparer;
 #endif
@@ -142,9 +145,12 @@ public virtual IApiVersionReader Build() =>
 #if NET45
             included ?? [],
             excluded ?? [],
-#else
+#elif NETFRAMEWORK
             included ?? new( capacity: 0 ),
             excluded ?? new( capacity: 0 ),
+#else
+            included?.ToFrozenSet( included.Comparer ) ?? FrozenSet<Str>.Empty,
+            excluded?.ToFrozenSet( excluded.Comparer ) ?? FrozenSet<Str>.Empty,
 #endif
             select ?? DefaultSelector,
             readers?.ToArray() ?? [] );
@@ -285,15 +291,15 @@ private static string[] ReadMediaTypeParameter(
     private sealed class BuiltMediaTypeApiVersionReader : IApiVersionReader
     {
         private readonly string[] parameters;
-        private readonly HashSet<Str> included;
-        private readonly HashSet<Str> excluded;
+        private readonly FrozenSet included;
+        private readonly FrozenSet excluded;
         private readonly SelectorCallback selector;
         private readonly ReaderCallback[] readers;
 
         internal BuiltMediaTypeApiVersionReader(
             string[] parameters,
-            HashSet<Str> included,
-            HashSet<Str> excluded,
+            FrozenSet included,
+            FrozenSet excluded,
             SelectorCallback selector,
             ReaderCallback[] readers )
         {