Implement scoped lifetime disposal with automatic resource cleanup via Scope object

Author: NikolayPianikov

readme/FooterTemplate.md

@@ -729,6 +729,7 @@ DI.Setup("Composition")
 | [DisableAutoBindingLifetimeRegularExpression](#disableautobindinglifetimeregularexpression-hint)                                     | Regular expression                         |            | .+        |
 | [DisableAutoBindingLifetimeWildcard](#disableautobindinglifetimewildcard-hint)                                                       | Wildcard                                   |            | *         |
 | [LightweightAnonymousRoot](#lightweightanonymousroot-hint)                                                                           | _On_ or _Off_                              |            | _On_      |
+| [ScopeFactoryName](#scopefactoryname-hint)                                                                                           | Method name                                |            |           |
 
 The list of hints will be gradually expanded to meet the needs and desires for fine-tuning code generation. Please feel free to add your ideas.
 
@@ -1396,6 +1397,17 @@ DI.Setup("Composition")
     .Bind<IService>().To<Service>();
 ```
 
+### ScopeFactoryName Hint
+
+Sets the scope factory name to be used for creating scopes.
+
+```c#
+// ScopeFactoryName = CreateScope
+DI.Setup("Composition")
+    .Hint(Hint.ScopeFactoryName, "CreateScope")
+    .Bind<IDependency>().As(Lifetime.Scoped).To<Dependency>();
+```
+
 </details>
 
 <details>

src/Pure.DI.Core/Components/Api.g.cs

@@ -1,4 +1,4 @@
-
+
 // <auto-generated/>
 #if !PUREDI_API_SUPPRESSION || PUREDI_API_V2
 #pragma warning disable
@@ -1189,6 +1189,18 @@ internal enum Hint
         /// </example>
         /// </summary>
         LightweightAnonymousRoot,
+
+        /// <summary>
+        /// Sets the scope factory name to be used for creating scopes.
+        /// <example>
+        /// <code>
+        /// DI.Setup("Composition")
+        ///     .Hint(Hint.ScopeFactoryName, "CreateScope")
+        ///     .Bind&lt;IDependency&gt;().As(Lifetime.Scoped).To&lt;Dependency&gt;();
+        /// </code>
+        /// </example>
+        /// </summary>
+        ScopeFactoryName,
     }
 
     /// <summary>

src/Pure.DI.Core/Components/Api.g.tt

@@ -1194,6 +1194,18 @@ namespace Pure.DI
         /// </example>
         /// </summary>
         LightweightAnonymousRoot,
+
+        /// <summary>
+        /// Sets the scope factory name to be used for creating scopes.
+        /// <example>
+        /// <code>
+        /// DI.Setup("Composition")
+        ///     .Hint(Hint.ScopeFactoryName, "CreateScope")
+        ///     .Bind&lt;IDependency&gt;().As(Lifetime.Scoped).To&lt;Dependency&gt;();
+        /// </code>
+        /// </example>
+        /// </summary>
+        ScopeFactoryName,
     }
 
     /// <summary>

src/Pure.DI.Core/Core/Code/Constructors.cs

@@ -29,11 +29,15 @@ from edge in entry.Edges
         from node in ImmutableArray.Create(edge.Source, edge.Target)
         where node.Arg is { Source.Kind: ArgKind.Composition }
         where bindingsRegistry.IsRegistered(graph.Source, node.BindingId)
-        select node).Any() || HasSetupContextArgs(graph) || IsScopeEnabled(graph);
+        select node).Any() || HasSetupContextArgs(graph) || HasScopedLifetimes(graph);
 
-    private bool IsScopeEnabled(DependencyGraph graph) => (
+    private bool HasScopedLifetimes(DependencyGraph graph) => (
         from node in graph.Graph.Vertices
         where node.ActualLifetime == Lifetime.Scoped
         where bindingsRegistry.IsRegistered(graph.Source, node.BindingId)
         select node).Any();
+
+    private bool IsScopeEnabled(DependencyGraph graph) =>
+        graph.Source.Hints.ScopeStrategy == ScopeStrategy.CompositionInstance
+        && HasScopedLifetimes(graph);
 }

src/Pure.DI.Core/Core/Code/DisposalStatementsBuilder.cs

@@ -0,0 +1,111 @@
+// ReSharper disable InvertIf
+namespace Pure.DI.Core.Code;
+
+sealed class DisposalStatementsBuilder : IDisposalStatementsBuilder
+{
+    public void AddDisposeLoop(
+        Lines code,
+        bool hasDisposable,
+        bool hasAsyncDisposable,
+        bool isAsync,
+        string onDisposeExceptionCall,
+        string onDisposeAsyncExceptionCall)
+    {
+        code.AppendLine("while (disposeIndex-- > 0)");
+        using (code.CreateBlock())
+        {
+            code.AppendLine("switch (disposables[disposeIndex])");
+            using (code.CreateBlock())
+            {
+                if (isAsync)
+                {
+                    if (hasAsyncDisposable)
+                    {
+                        AddDisposeAsyncPart(code, true, onDisposeAsyncExceptionCall);
+                    }
+
+                    if (hasDisposable)
+                    {
+                        if (hasAsyncDisposable)
+                        {
+                            code.AppendLine();
+                        }
+
+                        AddDisposePart(code, onDisposeExceptionCall);
+                    }
+                }
+                else
+                {
+                    if (hasDisposable)
+                    {
+                        AddDisposePart(code, onDisposeExceptionCall);
+                    }
+
+                    if (hasAsyncDisposable)
+                    {
+                        if (hasDisposable)
+                        {
+                            code.AppendLine();
+                        }
+
+                        AddDisposeAsyncPart(code, false, onDisposeAsyncExceptionCall);
+                    }
+                }
+            }
+        }
+    }
+
+    private static void AddDisposeAsyncPart(Lines code, bool makeAsyncCall, string onDisposeAsyncExceptionCall)
+    {
+        code.AppendLine($"case {Names.IAsyncDisposableTypeName} asyncDisposableInstance:");
+        using (code.Indent())
+        {
+            code.AppendLine("try");
+            using (code.CreateBlock())
+            {
+                if (makeAsyncCall)
+                {
+                    code.AppendLine("await asyncDisposableInstance.DisposeAsync();");
+                }
+                else
+                {
+                    code.AppendLine("var valueTask = asyncDisposableInstance.DisposeAsync();");
+                    code.AppendLine("if (!valueTask.IsCompleted)");
+                    using (code.CreateBlock())
+                    {
+                        code.AppendLine("valueTask.AsTask().Wait();");
+                    }
+                }
+            }
+
+            code.AppendLine($"catch ({Names.ExceptionTypeName} exception)");
+            using (code.CreateBlock())
+            {
+                code.AppendLine($"{onDisposeAsyncExceptionCall};");
+            }
+
+            code.AppendLine("break;");
+        }
+    }
+
+    private static void AddDisposePart(Lines code, string onDisposeExceptionCall)
+    {
+        code.AppendLine($"case {Names.IDisposableTypeName} disposableInstance:");
+        using (code.Indent())
+        {
+            code.AppendLine("try");
+            using (code.CreateBlock())
+            {
+                code.AppendLine("disposableInstance.Dispose();");
+            }
+
+            code.AppendLine($"catch ({Names.ExceptionTypeName} exception)");
+            using (code.CreateBlock())
+            {
+                code.AppendLine($"{onDisposeExceptionCall};");
+            }
+
+            code.AppendLine("break;");
+        }
+    }
+}

src/Pure.DI.Core/Core/Code/IDisposalStatementsBuilder.cs

@@ -0,0 +1,12 @@
+namespace Pure.DI.Core.Code;
+
+interface IDisposalStatementsBuilder
+{
+    void AddDisposeLoop(
+        Lines code,
+        bool hasDisposable,
+        bool hasAsyncDisposable,
+        bool isAsync,
+        string onDisposeExceptionCall,
+        string onDisposeAsyncExceptionCall);
+}

src/Pure.DI.Core/Core/Code/Parts/ClassPart.cs

@@ -8,6 +8,7 @@ enum ClassPart
     ParameterizedConstructor,
     DefaultConstructor,
     ScopeConstructor,
+    ScopeClass,
     RootMethods,
     ApiMembers,
     DisposeMethod,

src/Pure.DI.Core/Core/Code/Parts/DefaultConstructorBuilder.cs

@@ -20,6 +20,13 @@ public CompositionCode Build(CompositionCode composition)
         var code = composition.Code;
         var membersCounter = composition.MembersCount;
         var hints = composition.Source.Source.Hints;
+        var scopeStrategy = hints.ScopeStrategy;
+        var hasScopeFactory = scopeStrategy == ScopeStrategy.ScopeFactory;
+        var hasScopedLifetimes = composition.Singletons.Any(i => i.Node.ActualLifetime == Lifetime.Scoped);
+        var hasSingletonLifetimes = composition.Singletons.Any(i => i.Node.ActualLifetime == Lifetime.Singleton);
+        var rootDisposablesCount = hasScopeFactory
+            ? composition.TotalDisposablesCount - composition.DisposablesScopedCount
+            : composition.TotalDisposablesCount;
         var isCommentsEnabled = hints.IsCommentsEnabled;
         if (isCommentsEnabled)
         {
@@ -33,7 +40,7 @@ public CompositionCode Build(CompositionCode composition)
         code.AppendLine($"public {ctorName}()");
         using (code.CreateBlock())
         {
-            if (composition.Singletons.Length > 0)
+            if (hasSingletonLifetimes)
             {
                 code.AppendLine($"{Names.RootFieldName} = this;");
             }
@@ -47,9 +54,14 @@ public CompositionCode Build(CompositionCode composition)
                 code.AppendLine(new Line(int.MinValue, "#endif"));
             }
 
-            if (composition.TotalDisposablesCount > 0)
+            if (rootDisposablesCount > 0)
             {
-                code.AppendLine($"{Names.DisposablesFieldName} = new object[{composition.TotalDisposablesCount.ToString()}];");
+                code.AppendLine($"{Names.DisposablesFieldName} = new object[{rootDisposablesCount.ToString()}];");
+            }
+
+            if (hasScopeFactory && hasScopedLifetimes)
+            {
+                code.AppendLine($"{Names.RootScopeFieldName} = new {Names.ScopeClassName}(this, isRootScope: true);");
             }
         }