#11 Changed the visitors list in QbservableServiceOptions to a list o…

…f visitor factories.
RxDave · Aug 23, 2017 · 84aa7c0 · 84aa7c0
1 parent 139ed4f
commit 84aa7c0
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Showing 5 changed files with 13 additions and 12 deletions.
diff --git a/Source/Qactive/QbservableServiceOptions.cs b/Source/Qactive/QbservableServiceOptions.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Diagnostics.Contracts;
 using System.Linq.Expressions;
 
@@ -27,7 +26,7 @@ public sealed class QbservableServiceOptions
       evaluationContext = new ServiceEvaluationContext()
     };
 
-    private readonly List<ExpressionVisitor> visitors = new List<ExpressionVisitor>();
+    private readonly List<Func<ExpressionVisitor>> visitorFactories = new List<Func<ExpressionVisitor>>();
     private bool sendServerErrorsToClients;
     private bool enableDuplex;
     private bool allowExpressionsUnrestricted;
@@ -38,7 +37,7 @@ public sealed class QbservableServiceOptions
     [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Justification = "Required for code contracts.")]
     private void ObjectInvariant()
     {
-      Contract.Invariant(visitors != null);
+      Contract.Invariant(visitorFactories != null);
     }
 
     public bool IsFrozen { get; private set; }
@@ -86,9 +85,9 @@ public bool AllowExpressionsUnrestricted
     }
 
 #if READONLYCOLLECTIONS
-    public IReadOnlyList<ExpressionVisitor> Visitors => visitors.AsReadOnly();
+    public IReadOnlyList<Func<ExpressionVisitor>> VisitorFactories => visitorFactories.AsReadOnly();
 #else
-    public ReadOnlyCollection<ExpressionVisitor> Visitors => visitors.AsReadOnly();
+    public ReadOnlyCollection<Func<ExpressionVisitor>> VisitorFactories => visitors.AsReadOnly();
 #endif
 
     public ExpressionOptions ExpressionOptions
@@ -143,13 +142,13 @@ public QbservableServiceOptions(QbservableServiceOptions clone)
       evaluationContext = clone.evaluationContext;
     }
 
-    public QbservableServiceOptions Add(ExpressionVisitor visitor)
+    public QbservableServiceOptions Add(Func<ExpressionVisitor> visitorFactory)
     {
-      Contract.Requires(visitor != null);
+      Contract.Requires(visitorFactory != null);
 
       var options = IsFrozen ? Clone() : this;
 
-      options.visitors.Add(visitor);
+      options.visitorFactories.Add(visitorFactory);
 
       return options;
     }

diff --git a/Source/Qactive/ServerQuery.cs b/Source/Qactive/ServerQuery.cs
@@ -135,8 +135,10 @@ private Expression PrepareExpression(out IQbservableProvider realProvider)
 
       preparedExpression = visitor.Visit(preparedExpression);
 
-      foreach (var customVisitor in Provider.Options.Visitors)
+      foreach (var customVisitorFactory in Provider.Options.VisitorFactories)
       {
+        var customVisitor = customVisitorFactory();
+
         preparedExpression = customVisitor.Visit(preparedExpression);
       }
 

diff --git a/Testing/Qactive.Tests/ServiceOptions/VisitorTests.cs b/Testing/Qactive.Tests/ServiceOptions/VisitorTests.cs
@@ -14,7 +14,7 @@ public class VisitorTests : TestBase
     public async Task SimpleVisitor()
     {
       var visitor = new TestExpressionVisitor();
-      var service = TestService.Create(QbservableServiceOptions.Default.Add(visitor), Observable.Range(1, 5));
+      var service = TestService.Create(QbservableServiceOptions.Default.Add(() => visitor), Observable.Range(1, 5));
 
       var results = await service.QueryAsync(source => from value in source
                                                        where value % 2 == 0

diff --git a/Testing/Qactive.Tests/Tcp/ServiceOptions/VisitorTests.cs b/Testing/Qactive.Tests/Tcp/ServiceOptions/VisitorTests.cs
@@ -14,7 +14,7 @@ public class VisitorTests : TestBase
     public async Task SimpleVisitor()
     {
       var visitor = new TestExpressionVisitor();
-      var service = TcpTestService.Create(QbservableServiceOptions.Default.Add(visitor), Observable.Range(1, 5));
+      var service = TcpTestService.Create(QbservableServiceOptions.Default.Add(() => visitor), Observable.Range(1, 5));
 
       var results = await service.QueryAsync(source => from value in source
                                                        where value % 2 == 0

diff --git a/Testing/Qactive.Tests/WebSockets/ServiceOptions/VisitorTests.cs b/Testing/Qactive.Tests/WebSockets/ServiceOptions/VisitorTests.cs
@@ -14,7 +14,7 @@ public class VisitorTests : TestBase
     public async Task SimpleVisitor()
     {
       var visitor = new TestExpressionVisitor();
-      var service = WebSocketTestService.Create(QbservableServiceOptions.Default.Add(visitor), Observable.Range(1, 5));
+      var service = WebSocketTestService.Create(QbservableServiceOptions.Default.Add(() => visitor), Observable.Range(1, 5));
 
       var results = await service.QueryAsync(source => from value in source
                                                        where value % 2 == 0