Allocation cleanup

.github/pull_request_template.md

@@ -0,0 +1,7 @@
+## Why this PR?
+
+-motivation for making this change-
+
+## Visible Changes
+
+-changes that are visible to developers using this library-

examples/ConsoleApp/ConsoleApp.csproj

@@ -7,9 +7,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.0" />
-    <PackageReference Include="System.Text.Json" Version="8.0.4" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.1" />
+    <PackageReference Include="System.Text.Json" Version="8.0.5" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
   </ItemGroup>
 
   <ItemGroup>

examples/ConsoleApp/appsettings.json

@@ -17,4 +17,4 @@
       }
     ]
   }
-}
+}

examples/TargetingConsoleApp/TargetingConsoleApp.csproj

@@ -7,9 +7,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.0" />
-    <PackageReference Include="System.Text.Json" Version="8.0.4" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.1" />
+    <PackageReference Include="System.Text.Json" Version="8.0.5" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
   </ItemGroup>
 
   <ItemGroup>

src/Microsoft.FeatureManagement.AspNetCore/FeatureGateAttribute.cs

@@ -95,7 +95,7 @@ public FeatureGateAttribute(RequirementType requirementType, params object[] fea
         public RequirementType RequirementType { get; }
 
         /// <summary>
-        /// Performs controller action pre-procesing to ensure that any or all of the specified features are enabled.
+        /// Performs controller action pre-processing to ensure that any or all of the specified features are enabled.
         /// </summary>
         /// <param name="context">The context of the MVC action.</param>
         /// <param name="next">The action delegate.</param>

src/Microsoft.FeatureManagement/ConfigurationFeatureDefinitionProvider.cs

@@ -24,9 +24,10 @@ public sealed class ConfigurationFeatureDefinitionProvider : IFeatureDefinitionP
         // provider to be marked for caching as well.
 
         private readonly IConfiguration _configuration;
-        private readonly ConcurrentDictionary<string, FeatureDefinition> _definitions;
+        private readonly ConcurrentDictionary<string, Task<FeatureDefinition>> _definitions;
         private IDisposable _changeSubscription;
         private int _stale = 0;
+        public Func<string, Task<FeatureDefinition>> schemaReadFunc;
 
         const string ParseValueErrorString = "Invalid setting '{0}' with value '{1}' for feature '{2}'.";
 
@@ -37,11 +38,16 @@ public sealed class ConfigurationFeatureDefinitionProvider : IFeatureDefinitionP
         public ConfigurationFeatureDefinitionProvider(IConfiguration configuration)
         {
             _configuration = configuration ?? throw new ArgumentNullException(nameof(configuration));
-            _definitions = new ConcurrentDictionary<string, FeatureDefinition>();
+            _definitions = new ConcurrentDictionary<string, Task<FeatureDefinition>>();
 
             _changeSubscription = ChangeToken.OnChange(
                 () => _configuration.GetReloadToken(),
                 () => _stale = 1);
+
+            schemaReadFunc = (featureName) =>
+            {
+                return Task.FromResult(GetMicrosoftSchemaFeatureDefinition(featureName, _configuration) ?? GetDotnetSchemaFeatureDefinition(featureName, _configuration, RootConfigurationFallbackEnabled));
+            };
         }
 
         /// <summary>
@@ -69,6 +75,7 @@ public void Dispose()
         /// </summary>
         /// <param name="featureName">The name of the feature to retrieve the definition for.</param>
         /// <returns>The feature's definition.</returns>
+
         public Task<FeatureDefinition> GetFeatureDefinitionAsync(string featureName)
         {
             if (featureName == null)
@@ -86,10 +93,7 @@ public Task<FeatureDefinition> GetFeatureDefinitionAsync(string featureName)
                 _definitions.Clear();
             }
 
-            return Task.FromResult(
-                _definitions.GetOrAdd(
-                    featureName,
-                    (_) => GetMicrosoftSchemaFeatureDefinition(featureName) ?? GetDotnetSchemaFeatureDefinition(featureName)));
+            return _definitions.GetOrAdd(featureName, schemaReadFunc);
         }
 
         /// <summary>
@@ -98,7 +102,7 @@ public Task<FeatureDefinition> GetFeatureDefinitionAsync(string featureName)
         /// <returns>An enumerator which provides asynchronous iteration over feature definitions.</returns>
         //
         // The async key word is necessary for creating IAsyncEnumerable.
-        // The need to disable this warning occurs when implementaing async stream synchronously. 
+        // The need to disable this warning occurs when implementing async stream synchronously. 
 #pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
         public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync()
 #pragma warning restore CS1998
@@ -108,7 +112,7 @@ public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync()
                 _definitions.Clear();
             }
 
-            IEnumerable<IConfigurationSection> microsoftFeatureDefinitionSections = GetMicrosoftFeatureDefinitionSections();
+            IEnumerable<IConfigurationSection> microsoftFeatureDefinitionSections = GetMicrosoftFeatureDefinitionSections(_configuration);
 
             foreach (IConfigurationSection featureSection in microsoftFeatureDefinitionSections)
             {
@@ -121,15 +125,15 @@ public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync()
 
                 //
                 // Underlying IConfigurationSection data is dynamic so latest feature definitions are returned
-                FeatureDefinition definition = _definitions.GetOrAdd(featureName, (_) => ParseMicrosoftSchemaFeatureDefinition(featureSection));
+                FeatureDefinition definition = _definitions.GetOrAdd(featureName, schemaReadFunc).Result;
 
                 if (definition != null)
                 {
                     yield return definition;
                 }
             }
 
-            IEnumerable<IConfigurationSection> dotnetFeatureDefinitionSections = GetDotnetFeatureDefinitionSections();
+            IEnumerable<IConfigurationSection> dotnetFeatureDefinitionSections = GetDotnetFeatureDefinitionSections(_configuration, RootConfigurationFallbackEnabled);
 
             foreach (IConfigurationSection featureSection in dotnetFeatureDefinitionSections)
             {
@@ -142,7 +146,7 @@ public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync()
 
                 //
                 // Underlying IConfigurationSection data is dynamic so latest feature definitions are returned
-                FeatureDefinition definition = _definitions.GetOrAdd(featureName, (_) => ParseDotnetSchemaFeatureDefinition(featureSection));
+                FeatureDefinition definition = _definitions.GetOrAdd(featureName, schemaReadFunc).Result;
 
                 if (definition != null)
                 {
@@ -151,41 +155,41 @@ public async IAsyncEnumerable<FeatureDefinition> GetAllFeatureDefinitionsAsync()
             }
         }
 
-        private FeatureDefinition GetDotnetSchemaFeatureDefinition(string featureName)
+        private static FeatureDefinition GetDotnetSchemaFeatureDefinition(string featureName, IConfiguration configuration, bool rootConfigurationFallbackEnabled)
         {
-            IEnumerable<IConfigurationSection> dotnetFeatureDefinitionSections = GetDotnetFeatureDefinitionSections();
+            IEnumerable<IConfigurationSection> dotnetFeatureDefinitionSections = GetDotnetFeatureDefinitionSections(configuration, rootConfigurationFallbackEnabled);
 
-            IConfigurationSection configuration = dotnetFeatureDefinitionSections
+            IConfigurationSection dotnetFeatureDefinitionConfiguration = dotnetFeatureDefinitionSections
                 .FirstOrDefault(section =>
                     string.Equals(section.Key, featureName, StringComparison.OrdinalIgnoreCase));
 
-            if (configuration == null)
+            if (dotnetFeatureDefinitionConfiguration == null)
             {
                 return null;
             }
 
-            return ParseDotnetSchemaFeatureDefinition(configuration);
+            return ParseDotnetSchemaFeatureDefinition(dotnetFeatureDefinitionConfiguration);
         }
 
-        private FeatureDefinition GetMicrosoftSchemaFeatureDefinition(string featureName)
+        private static FeatureDefinition GetMicrosoftSchemaFeatureDefinition(string featureName, IConfiguration configuration)
         {
-            IEnumerable<IConfigurationSection> microsoftFeatureDefinitionSections = GetMicrosoftFeatureDefinitionSections();
+            IEnumerable<IConfigurationSection> microsoftFeatureDefinitionSections = GetMicrosoftFeatureDefinitionSections(configuration);
 
-            IConfigurationSection configuration = microsoftFeatureDefinitionSections
+            IConfigurationSection microsoftFeatureDefinitionConfiguration = microsoftFeatureDefinitionSections
                 .LastOrDefault(section =>
                     string.Equals(section[MicrosoftFeatureManagementFields.Id], featureName, StringComparison.OrdinalIgnoreCase));
 
-            if (configuration == null)
+            if (microsoftFeatureDefinitionConfiguration == null)
             {
                 return null;
             }
 
-            return ParseMicrosoftSchemaFeatureDefinition(configuration);
+            return ParseMicrosoftSchemaFeatureDefinition(microsoftFeatureDefinitionConfiguration);
         }
 
-        private IEnumerable<IConfigurationSection> GetDotnetFeatureDefinitionSections()
+        private static IEnumerable<IConfigurationSection> GetDotnetFeatureDefinitionSections(IConfiguration configuration, bool rootConfigurationFallbackEnabled)
         {
-            IConfigurationSection featureManagementConfigurationSection = _configuration.GetSection(DotnetFeatureManagementFields.FeatureManagementSectionName);
+            IConfigurationSection featureManagementConfigurationSection = configuration.GetSection(DotnetFeatureManagementFields.FeatureManagementSectionName);
 
             if (featureManagementConfigurationSection.Exists())
             {
@@ -195,25 +199,25 @@ private IEnumerable<IConfigurationSection> GetDotnetFeatureDefinitionSections()
             //
             // Root configuration fallback only applies to .NET schema.
             // If Microsoft schema can be found, root configuration fallback will not be effective.
-            if (RootConfigurationFallbackEnabled &&
-                !_configuration.GetChildren()
+            if (rootConfigurationFallbackEnabled &&
+                !configuration.GetChildren()
                     .Any(section =>
                         string.Equals(section.Key, MicrosoftFeatureManagementFields.FeatureManagementSectionName, StringComparison.OrdinalIgnoreCase)))
             {
-                return _configuration.GetChildren();
+                return configuration.GetChildren();
             }
 
             return Enumerable.Empty<IConfigurationSection>();
         }
 
-        private IEnumerable<IConfigurationSection> GetMicrosoftFeatureDefinitionSections()
+        private static IEnumerable<IConfigurationSection> GetMicrosoftFeatureDefinitionSections(IConfiguration configuration)
         {
-            return _configuration.GetSection(MicrosoftFeatureManagementFields.FeatureManagementSectionName)
+            return configuration.GetSection(MicrosoftFeatureManagementFields.FeatureManagementSectionName)
                 .GetSection(MicrosoftFeatureManagementFields.FeatureFlagsSectionName)
                 .GetChildren();
         }
 
-        private FeatureDefinition ParseDotnetSchemaFeatureDefinition(IConfigurationSection configurationSection)
+        private static FeatureDefinition ParseDotnetSchemaFeatureDefinition(IConfigurationSection configurationSection)
         {
             /*
 
@@ -304,7 +308,7 @@ We support
             };
         }
 
-        private FeatureDefinition ParseMicrosoftSchemaFeatureDefinition(IConfigurationSection configurationSection)
+        private static FeatureDefinition ParseMicrosoftSchemaFeatureDefinition(IConfigurationSection configurationSection)
         {
             /*
 
@@ -518,7 +522,7 @@ private FeatureDefinition ParseMicrosoftSchemaFeatureDefinition(IConfigurationSe
             };
         }
 
-        private T ParseEnum<T>(string feature, string rawValue, string fieldKeyword)
+        private static T ParseEnum<T>(string feature, string rawValue, string fieldKeyword)
             where T : struct, Enum
         {
             Debug.Assert(!string.IsNullOrEmpty(rawValue));
@@ -533,7 +537,7 @@ private T ParseEnum<T>(string feature, string rawValue, string fieldKeyword)
             return value;
         }
 
-        private double ParseDouble(string feature, string rawValue, string fieldKeyword)
+        private static double ParseDouble(string feature, string rawValue, string fieldKeyword)
         {
             Debug.Assert(!string.IsNullOrEmpty(rawValue));
 
@@ -547,7 +551,7 @@ private double ParseDouble(string feature, string rawValue, string fieldKeyword)
             return value;
         }
 
-        private bool ParseBool(string feature, string rawValue, string fieldKeyword)
+        private static bool ParseBool(string feature, string rawValue, string fieldKeyword)
         {
             Debug.Assert(!string.IsNullOrEmpty(rawValue));