Optimizations: Memoize Attributes in AttributeHelper and ServiceRegistrations

Dont use LINQ in ServiceRegistration

Don't use LINQ .ToArray() in AttributeHelper.GetAttributes()

precompute typeof() in static

Optimize ServiceContainer.Create()

Optimization: Memoize TypeHelper.GetConstructor()

Remove automatically inserted `using System.Diagnostics.CodeAnalysis`

Simple formatting

private specifier

Refactoring

User .SequenceEqual()  in TYpesComparer

Refactor TypesCompares.GetHashCode()

Rename TypesEqualityComparer

typeofIServiceContainer

Optimization: cache ServiceRegistration[] in DomainTypeRegistry

public -> private

Small optimizations: avoid LINQ in critical places

Revert to SequenceEqual in TypesEqualityComparer.Equals()

Remove comment

reorder public/private methods

Author: SergeiPavlov

Orm/Xtensive.Orm/Collections/TypeRegistry.cs

@@ -11,7 +11,7 @@
 using System.Reflection;
 using System.Linq;
 using Xtensive.Core;
-
+using Xtensive.IoC;
 
 namespace Xtensive.Collections
 {
@@ -33,6 +33,7 @@ public class TypeRegistry : LockableBase,
     private readonly ITypeRegistrationProcessor processor;
     private bool isProcessingPendingActions = false;
     private readonly Set<Assembly> assemblies = new Set<Assembly>();
+    protected ServiceRegistration[] serviceRegistrations;
 
     /// <summary>
     /// Gets assemblies containing registered types.
@@ -63,6 +64,7 @@ public void Register(Type type)
       else {
         if (typeSet.Contains(type))
           return;
+        serviceRegistrations = null;
         types.Add(type);
         typeSet.Add(type);
         assemblies.Add(type.Assembly);

Orm/Xtensive.Orm/IoC/Internals/DefaultServiceContainer.cs

@@ -38,10 +38,7 @@ private IServiceContainer GetContainer(Type serviceType)
       return containers.GetValue(assembly, _assembly => {
         var typeRegistry = new TypeRegistry(new ServiceTypeRegistrationProcessor());
         typeRegistry.Register(_assembly);
-        return new ServiceContainer(
-          from type in typeRegistry
-          from serviceRegistration in ServiceRegistration.CreateAll(type, true)
-          select serviceRegistration);
+        return new ServiceContainer(typeRegistry.SelectMany(type => ServiceRegistration.CreateAll(type, true)));
       });
     }
   }

Orm/Xtensive.Orm/IoC/ServiceContainer.cs

@@ -19,14 +19,18 @@
 
 namespace Xtensive.IoC
 {
+  using Key = ValueTuple<Type, string>;
+
   /// <summary>
   /// Default IoC (inversion of control) container implementation.
   /// </summary>
   [Serializable]
   public class ServiceContainer : ServiceContainerBase
   {
-    private readonly Dictionary<object, List<ServiceRegistration>> types =
-      new Dictionary<object, List<ServiceRegistration>>();
+    private static Type typeofIServiceContainer =   typeof(IServiceContainer);
+
+    private readonly Dictionary<Key, List<ServiceRegistration>> types =
+      new Dictionary<Key, List<ServiceRegistration>>();
     private readonly Dictionary<ServiceRegistration, object> instances =
       new Dictionary<ServiceRegistration, object>();
     private readonly Dictionary<ServiceRegistration, Pair<ConstructorInfo, ParameterInfo[]>> constructorCache =
@@ -42,14 +46,13 @@ protected override object HandleGet(Type serviceType, string name)
     {
       // Not very optimal, but...
       lock (_lock) {
-        List<ServiceRegistration> list;
-        if (!types.TryGetValue(GetKey(serviceType, name), out list))
-          return null;
-        if (list.Count == 0)
+        if (!types.TryGetValue(GetKey(serviceType, name), out var list))
           return null;
-        if (list.Count > 1)
-          throw new AmbiguousMatchException(Strings.ExMultipleServicesMatchToTheSpecifiedArguments);
-        return GetOrCreateInstances(list).Single();
+        return list.Count switch {
+          0 => null,
+          1 => GetOrCreateInstances(list).Single(),
+          _ => throw new AmbiguousMatchException(Strings.ExMultipleServicesMatchToTheSpecifiedArguments)
+        };
       }
     }
 
@@ -58,10 +61,9 @@ protected override IEnumerable<object> HandleGetAll(Type serviceType)
     {
       // Not very optimal, but...
       lock (_lock) {
-        List<ServiceRegistration> list;
-        if (!types.TryGetValue(GetKey(serviceType, null), out list))
-          return EnumerableUtils<object>.Empty;
-        return GetOrCreateInstances(list);
+        return types.TryGetValue(GetKey(serviceType, null), out var list)
+          ? GetOrCreateInstances(list)
+          : Array.Empty<object>();
       }
     }
 
@@ -111,13 +113,8 @@ select c
 
     #region Private \ internal methods
 
-    private static object GetKey(Type serviceType, string name)
-    {
-      if (name.IsNullOrEmpty())
-        return serviceType;
-      else
-        return new ObjectPair(serviceType, name);
-    }
+    private static Key GetKey(Type serviceType, string name) =>
+      new Key(serviceType, string.IsNullOrEmpty(name) ? null : name);
 
     private IEnumerable<object> GetOrCreateInstances(IEnumerable<ServiceRegistration> services)
     {
@@ -141,11 +138,9 @@ private IEnumerable<object> GetOrCreateInstances(IEnumerable<ServiceRegistration
 
     private void Register(ServiceRegistration serviceRegistration)
     {
-      List<ServiceRegistration> list;
       var key = GetKey(serviceRegistration.Type, serviceRegistration.Name);
-      if (!types.TryGetValue(key, out list)) {
-        list = new List<ServiceRegistration>();
-        types[key] = list;
+      if (!types.TryGetValue(key, out var list)) {
+        types[key] = list = new List<ServiceRegistration>();
       }
       list.Add(serviceRegistration);
     }
@@ -201,25 +196,23 @@ public static IServiceContainer Create(Type containerType, object configuration)
     public static IServiceContainer Create(Type containerType, object configuration, IServiceContainer parent)
     {
       ArgumentValidator.EnsureArgumentNotNull(containerType, "containerType");
-      if (!typeof(IServiceContainer).IsAssignableFrom(containerType))
+      if (!typeofIServiceContainer.IsAssignableFrom(containerType))
         throw new ArgumentException(string.Format(
-          Strings.ExContainerTypeMustImplementX, typeof(IServiceContainer).GetShortName()), "containerType");
-
-      var possibleArgs =
-        Enumerable.Empty<object[]>()
-          .Append(new[] { configuration, parent })
-          .Append(new[] { configuration })
-          .Append(new[] { parent });
-      foreach (var args in possibleArgs) {
-        var ctor = containerType.GetConstructor(args);
-        if (ctor != null)
-          return (IServiceContainer) ctor.Invoke(args);
-      }
-
-      throw new ArgumentException(
-        Strings.ExContainerTypeDoesNotProvideASuitableConstructor, "containerType");
+          Strings.ExContainerTypeMustImplementX, typeofIServiceContainer.GetShortName()), "containerType");
+
+      Type configurationType = configuration?.GetType(),
+        parentType = parent?.GetType();
+      return (IServiceContainer)(
+        FindConstructor(containerType, configurationType, parentType)?.Invoke(new[] { configuration, parent })
+        ?? FindConstructor(containerType, configurationType)?.Invoke(new[] { configuration })
+        ?? FindConstructor(containerType, parentType)?.Invoke(new[] { parent })
+        ?? throw new ArgumentException(Strings.ExContainerTypeDoesNotProvideASuitableConstructor, "containerType")
+      );
     }
 
+    private static ConstructorInfo FindConstructor(Type containerType, params Type[] argumentTypes) =>
+      containerType.GetSingleConstructor(argumentTypes);
+
     #endregion
 
     /// <summary>
@@ -284,10 +277,8 @@ public static IServiceContainer Create(ConfigurationSection section, string name
       if (name.IsNullOrEmpty())
         name = string.Empty;
 
-      ContainerElement configuration = section == null ? null : section.Containers[name];
-
-      if (configuration == null)
-        configuration = new ContainerElement();
+      ContainerElement configuration = section?.Containers[name]
+        ?? new ContainerElement();
 
       var registrations = new List<ServiceRegistration>();
       var typeRegistry = new TypeRegistry(new ServiceTypeRegistrationProcessor());

Orm/Xtensive.Orm/IoC/ServiceRegistration.cs

@@ -5,20 +5,24 @@
 // Created:    2009.10.12
 
 using System;
-using Xtensive.Collections;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
 using Xtensive.Core;
-using System.Linq;
-
 using Xtensive.Reflection;
 
 namespace Xtensive.IoC
 {
+  using ServiceRegistrationKey = ValueTuple<Type, bool>;
+
   /// <summary>
   /// Describes single service mapping entry for <see cref="ServiceContainer"/>.
   /// </summary>
   [Serializable]
   public sealed class ServiceRegistration
   {
+    private static readonly ConcurrentDictionary<ServiceRegistrationKey, ServiceRegistration[]> serviceRegistrationsByType =
+      new ConcurrentDictionary<ServiceRegistrationKey, ServiceRegistration[]>();
+
     /// <summary>
     /// Gets the type of the service.
     /// </summary>
@@ -56,10 +60,8 @@ public sealed class ServiceRegistration
     /// <returns>
     /// An array of <see cref="ServiceRegistration"/> objects.
     /// </returns>
-    public static ServiceRegistration[] CreateAll(Type type)
-    {
-      return CreateAll(type, false);
-    }
+    public static ServiceRegistration[] CreateAll(Type type) =>
+      CreateAll(type, false);
 
     /// <summary>
     /// Creates an array of <see cref="ServiceRegistration"/> objects
@@ -72,27 +74,24 @@ public static ServiceRegistration[] CreateAll(Type type)
     /// <returns>
     /// An array of <see cref="ServiceRegistration"/> objects.
     /// </returns>
-    public static ServiceRegistration[] CreateAll(Type type, bool defaultOnly)
-    {
+    public static ServiceRegistration[] CreateAll(Type type, bool defaultOnly) =>
+      serviceRegistrationsByType.GetOrAdd(new ServiceRegistrationKey(type, defaultOnly), ServiceRegistrationsExtractor);
+
+    private static readonly Func<ServiceRegistrationKey, ServiceRegistration[]> ServiceRegistrationsExtractor = ((Type type, bool defaultOnly) t) => {
+      (var type, var defaultOnly) = t;
       ArgumentValidator.EnsureArgumentNotNull(type, "type");
       if (type.IsAbstract)
-        return ArrayUtils<ServiceRegistration>.EmptyArray;
+        return Array.Empty<ServiceRegistration>();
 
       var attributes = type.GetAttributes<ServiceAttribute>(AttributeSearchOptions.InheritNone);
-      if (attributes == null)
-        return ArrayUtils<ServiceRegistration>.EmptyArray;
-      if (defaultOnly)
-        attributes = attributes.Where(a => a.Default).ToArray();
-      if (attributes.Length == 0)
-        return ArrayUtils<ServiceRegistration>.EmptyArray;
-
-      var result = new ServiceRegistration[attributes.Length];
-      for (int i = 0; i < attributes.Length; i++) {
-        var sa = attributes[i];
-        result[i] = new ServiceRegistration(sa.Type, sa.Name.IsNullOrEmpty() ? null : sa.Name, type, sa.Singleton);
+      var registrations = new List<ServiceRegistration>(attributes.Length);
+      foreach (var sa in attributes) {
+        if (!defaultOnly || sa.Default) {
+          registrations.Add(new ServiceRegistration(sa.Type, sa.Name.IsNullOrEmpty() ? null : sa.Name, type, sa.Singleton));
+        }
       }
-      return result;
-    }
+      return registrations.ToArray();
+    };
 
 
     // Constructors

Orm/Xtensive.Orm/Orm/Configuration/DomainTypeRegistry.cs

@@ -8,6 +8,7 @@
 using System.Collections.Generic;
 using Xtensive.Collections;
 using System.Linq;
+using Xtensive.IoC;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Upgrade;
 
@@ -42,6 +43,9 @@ public class DomainTypeRegistry : TypeRegistry
     /// </summary>
     public IEnumerable<Type> SessionServices => this.Where(IsSessionService);
 
+    public ServiceRegistration[] ServiceRegistrations =>
+      serviceRegistrations ??= SessionServices.SelectMany(ServiceRegistration.CreateAll).ToArray();
+
     /// <summary>
     /// Gets all the registered <see cref="IModule"/> implementations.
     /// </summary>

Orm/Xtensive.Orm/Orm/Session.cs

@@ -70,6 +70,12 @@ public partial class Session : DomainBound,
     private const string IdentifierFormat = "#{0}";
     private const string FullNameFormat = "{0}, #{1}";
 
+    private static readonly Type
+      typeofSession = typeof(Session),
+      typeofSessionConfiguration = typeof(SessionConfiguration),
+      typeofSessionHandler = typeof(SessionHandler),
+      typeofServiceContainer = typeof(ServiceContainer);
+
     private static Func<Session> resolver;
     private static long lastUsedIdentifier;
 
@@ -291,18 +297,18 @@ private EnumerationContextOptions GetEnumerationContextOptions()
     private IServiceContainer CreateSystemServices()
     {
       var registrations = new List<ServiceRegistration>{
-        new ServiceRegistration(typeof (Session), this),
-        new ServiceRegistration(typeof (SessionConfiguration), Configuration),
-        new ServiceRegistration(typeof (SessionHandler), Handler),
+        new ServiceRegistration(typeofSession, this),
+        new ServiceRegistration(typeofSessionConfiguration, Configuration),
+        new ServiceRegistration(typeofSessionHandler, Handler),
       };
       Handler.AddSystemServices(registrations);
       return new ServiceContainer(registrations, Domain.Services);
     }
 
     private IServiceContainer CreateServices()
     {
-      var userContainerType = Configuration.ServiceContainerType ?? typeof(ServiceContainer);
-      var registrations = Domain.Configuration.Types.SessionServices.SelectMany(ServiceRegistration.CreateAll);
+      var userContainerType = Configuration.ServiceContainerType ?? typeofServiceContainer;
+      var registrations = Domain.Configuration.Types.ServiceRegistrations;
       var systemContainer = CreateSystemServices();
       var userContainer = ServiceContainer.Create(userContainerType, systemContainer);
       return new ServiceContainer(registrations, userContainer);