From a137d84732ad51d4040e96f101b511a1511bb76b Mon Sep 17 00:00:00 2001
From: Louis DeJardin <Louis.DeJardin@microsoft.com>
Date: Sat, 17 Apr 2010 19:22:26 -0700
Subject: [PATCH] Working towards re-enabling setup context

--HG--
branch : dev
---
 src/Orchard.Specs/Bindings/WebAppHosting.cs   | 17 +++++
 .../Hosting/HostingTraceListener.cs           | 24 +++++++
 .../Orchard.Web/Config/Diagnostics.config     | 13 ++++
 .../Hosting/Orchard.Web/Web.config            |  2 +-
 src/Orchard.Specs/Hosting/WebHost.cs          |  1 +
 src/Orchard.Specs/Orchard.Specs.csproj        |  4 ++
 .../DefaultShellContextFactoryTests.cs        | 29 ++++++--
 .../Modules/Orchard.Setup/Module.txt          |  5 +-
 .../Environment/DefaultCompositionStrategy.cs | 13 ++--
 src/Orchard/Environment/DefaultOrchardHost.cs | 43 +++++++----
 src/Orchard/Environment/HostContext.cs        |  9 ---
 src/Orchard/Environment/OrchardStarter.cs     | 69 +++++++++++-------
 .../DefaultShellContextFactory.cs             | 72 +++++++++++++++----
 .../Models/ShellTopologyDescriptor.cs         |  6 ++
 src/Orchard/Orchard.Framework.csproj          |  1 -
 15 files changed, 235 insertions(+), 73 deletions(-)
 create mode 100644 src/Orchard.Specs/Hosting/HostingTraceListener.cs
 create mode 100644 src/Orchard.Specs/Hosting/Orchard.Web/Config/Diagnostics.config
 delete mode 100644 src/Orchard/Environment/HostContext.cs

diff --git a/src/Orchard.Specs/Bindings/WebAppHosting.cs b/src/Orchard.Specs/Bindings/WebAppHosting.cs
index 4e443c058..c13091bf8 100644
--- a/src/Orchard.Specs/Bindings/WebAppHosting.cs
+++ b/src/Orchard.Specs/Bindings/WebAppHosting.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
@@ -15,13 +16,29 @@ namespace Orchard.Specs.Bindings {
     public class WebAppHosting {
         private WebHost _webHost;
         private RequestDetails _details;
+        private MessageSink _messages;
 
         [Given(@"I have a clean site")]
         public void GivenIHaveACleanSite() {
             _webHost = new WebHost();
             _webHost.Initialize("Orchard.Web", "/");
+
+            var sink = new MessageSink();
+            _webHost.Execute(() => {
+                HostingTraceListener.SetHook(msg => sink.Receive(msg));
+            });
+            _messages = sink;
         }
 
+        public class MessageSink : MarshalByRefObject {
+            readonly IList<string> _messages = new List<string>();
+
+            public void Receive(string message) {
+                _messages.Add(message);
+            }
+        }
+
+
         [Given(@"I have module ""(.*)""")]
         public void GivenIHaveModule(string moduleName) {
             _webHost.CopyExtension("Modules", moduleName);
diff --git a/src/Orchard.Specs/Hosting/HostingTraceListener.cs b/src/Orchard.Specs/Hosting/HostingTraceListener.cs
new file mode 100644
index 000000000..f7f925d09
--- /dev/null
+++ b/src/Orchard.Specs/Hosting/HostingTraceListener.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Diagnostics;
+
+namespace Orchard.Specs.Hosting {
+    public class HostingTraceListener : TraceListener {
+        private static Action<string> _hook = ignored => { };
+        private string _message;
+
+        public static void SetHook(Action<string> hook) {
+            _hook = hook;
+        }
+
+        public override void Write(string message) {
+            var cumulative = _message + message;
+            _message = cumulative;
+        }
+
+        public override void WriteLine(string message) {
+            var cumulative = _message + message;
+            _message = null;
+            _hook(cumulative);
+        }
+    }
+}
diff --git a/src/Orchard.Specs/Hosting/Orchard.Web/Config/Diagnostics.config b/src/Orchard.Specs/Hosting/Orchard.Web/Config/Diagnostics.config
new file mode 100644
index 000000000..6e6223cdc
--- /dev/null
+++ b/src/Orchard.Specs/Hosting/Orchard.Web/Config/Diagnostics.config
@@ -0,0 +1,13 @@
+<system.diagnostics>
+  <trace autoflush="true"/>
+  <sources>
+    <source name="Default" switchValue="Verbose">
+      <listeners>
+        <add name="CaptureTraceMessages" />
+      </listeners>
+    </source>
+  </sources>
+  <sharedListeners>
+    <add name="CaptureTraceMessages" type="Orchard.Specs.Hosting.HostingTraceListener, Orchard.Specs" initializeData="" />
+  </sharedListeners>
+</system.diagnostics>
diff --git a/src/Orchard.Specs/Hosting/Orchard.Web/Web.config b/src/Orchard.Specs/Hosting/Orchard.Web/Web.config
index b9ed3c6de..91245e254 100644
--- a/src/Orchard.Specs/Hosting/Orchard.Web/Web.config
+++ b/src/Orchard.Specs/Hosting/Orchard.Web/Web.config
@@ -25,7 +25,7 @@
 
   <appSettings/>
 
-  <!--<system.diagnostics configSource="Config\Diagnostics.config" />-->
+  <system.diagnostics configSource="Config\Diagnostics.config" />
 
   <!-- 
         Set default transaction timeout to 30 minutes so that interactive debugging 
diff --git a/src/Orchard.Specs/Hosting/WebHost.cs b/src/Orchard.Specs/Hosting/WebHost.cs
index 65ab0081a..f395bfb18 100644
--- a/src/Orchard.Specs/Hosting/WebHost.cs
+++ b/src/Orchard.Specs/Hosting/WebHost.cs
@@ -33,6 +33,7 @@ namespace Orchard.Specs.Hosting {
             VirtualDirectory = virtualDirectory;
 
             _webHostAgent = (WebHostAgent)ApplicationHost.CreateApplicationHost(typeof(WebHostAgent), VirtualDirectory, PhysicalDirectory);
+
         }
 
         public void CopyExtension(string extensionFolder, string extensionName) {
diff --git a/src/Orchard.Specs/Orchard.Specs.csproj b/src/Orchard.Specs/Orchard.Specs.csproj
index 743127131..631eb3819 100644
--- a/src/Orchard.Specs/Orchard.Specs.csproj
+++ b/src/Orchard.Specs/Orchard.Specs.csproj
@@ -86,6 +86,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Hosting\HostingTraceListener.cs" />
     <Compile Include="Hosting\Orchard.Web\HelloYetAgainHandler.cs" />
     <Compile Include="Hosting\RequestExtensions.cs" />
     <Compile Include="Hosting\RequestDetails.cs" />
@@ -126,6 +127,9 @@
     <Content Include="Hosting\Orchard.Web\Themes\Web.config">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Content>
+    <None Include="Hosting\Orchard.Web\Config\Diagnostics.config">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
     <None Include="WebHosting.feature">
       <Generator>SpecFlowSingleFileGenerator</Generator>
       <LastGenOutput>WebHosting.feature.cs</LastGenOutput>
diff --git a/src/Orchard.Tests/Environment/ShellBuilders/DefaultShellContextFactoryTests.cs b/src/Orchard.Tests/Environment/ShellBuilders/DefaultShellContextFactoryTests.cs
index 9e97778cd..3ef30eb51 100644
--- a/src/Orchard.Tests/Environment/ShellBuilders/DefaultShellContextFactoryTests.cs
+++ b/src/Orchard.Tests/Environment/ShellBuilders/DefaultShellContextFactoryTests.cs
@@ -1,5 +1,6 @@
 using Autofac;
 using Autofac.Core.Registration;
+using Moq;
 using NUnit.Framework;
 using Orchard.Environment;
 using Orchard.Environment.Configuration;
@@ -17,16 +18,16 @@ namespace Orchard.Tests.Environment.ShellBuilders {
         public void Init() {
             var builder = new ContainerBuilder();
             builder.RegisterType<DefaultShellContextFactory>().As<IShellContextFactory>();
-            builder.RegisterAutoMocking();
+            builder.RegisterAutoMocking(Moq.MockBehavior.Strict);
             _container = builder.Build();
         }
 
         [Test]
         public void NormalExecutionReturnsExpectedObjects() {
-            var settings = new ShellSettings {Name = "Default"};
-            var topologyDescriptor = new ShellTopologyDescriptor {SerialNumber = 6655321};
+            var settings = new ShellSettings { Name = "Default" };
+            var topologyDescriptor = new ShellTopologyDescriptor { SerialNumber = 6655321 };
             var topology = new ShellTopology();
-            ILifetimeScope shellLifetimeScope;
+            var shellLifetimeScope = _container.BeginLifetimeScope("shell");
 
             _container.Mock<ITopologyDescriptorCache>()
                 .Setup(x => x.Fetch("Default"))
@@ -38,7 +39,7 @@ namespace Orchard.Tests.Environment.ShellBuilders {
 
             _container.Mock<IShellContainerFactory>()
                 .Setup(x => x.CreateContainer(topology))
-                .Returns(shellLifetimeScope = _container.BeginLifetimeScope("shell"));
+                .Returns(shellLifetimeScope );
 
             _container.Mock<ITopologyDescriptorManager>()
                 .Setup(x => x.GetTopologyDescriptor())
@@ -54,5 +55,23 @@ namespace Orchard.Tests.Environment.ShellBuilders {
             Assert.That(context.LifetimeScope, Is.SameAs(shellLifetimeScope));
             Assert.That(context.Shell, Is.SameAs(shellLifetimeScope.Resolve<IOrchardShell>()));
         }
+
+        [Test]
+        public void NullSettingsReturnsSetupContext() {
+            var topology = new ShellTopology();
+
+            _container.Mock<ICompositionStrategy>()
+                .Setup(x => x.Compose(It.IsAny<ShellTopologyDescriptor>()))
+                .Returns(topology);
+
+            _container.Mock<IShellContainerFactory>()
+                .Setup(x => x.CreateContainer(topology))
+                .Returns(_container.BeginLifetimeScope("shell"));
+
+            var factory = _container.Resolve<IShellContextFactory>();
+            var context = factory.Create(null);
+
+            Assert.That(context.TopologyDescriptor.EnabledFeatures, Has.Some.With.Property("Name").EqualTo("Setup"));
+        }
     }
 }
diff --git a/src/Orchard.Web/Modules/Orchard.Setup/Module.txt b/src/Orchard.Web/Modules/Orchard.Setup/Module.txt
index 774ff09db..def8d82d7 100644
--- a/src/Orchard.Web/Modules/Orchard.Setup/Module.txt
+++ b/src/Orchard.Web/Modules/Orchard.Setup/Module.txt
@@ -1,2 +1,5 @@
 name: Setup
-antiforgery: enabled
\ No newline at end of file
+antiforgery: enabled
+features:
+  Orchard.Setup:
+    description: Components needed to initialize a new instance or tenant
diff --git a/src/Orchard/Environment/DefaultCompositionStrategy.cs b/src/Orchard/Environment/DefaultCompositionStrategy.cs
index 77ba9b6c2..fc6dd5a94 100644
--- a/src/Orchard/Environment/DefaultCompositionStrategy.cs
+++ b/src/Orchard/Environment/DefaultCompositionStrategy.cs
@@ -47,6 +47,8 @@ namespace Orchard.Environment {
         }
 
         private static IEnumerable<Feature> CoreFeatures() {
+            var frameworkTypes = typeof(OrchardStarter).Assembly.GetExportedTypes();
+
             var core = new Feature {
                 Descriptor = new FeatureDescriptor {
                     Name = "Core",
@@ -56,11 +58,12 @@ namespace Orchard.Environment {
                         AntiForgery = "enabled",
                     },
                 },
-                ExportedTypes = new[] {
-                    typeof (ContentTypeRecord),
-                    typeof (ContentItemRecord),
-                    typeof (ContentItemVersionRecord),
-                },
+                ExportedTypes = frameworkTypes.Where(t => t.IsClass && !t.IsAbstract),
+                //ExportedTypes = new[] {
+                //    typeof (ContentTypeRecord),
+                //    typeof (ContentItemRecord),
+                //    typeof (ContentItemVersionRecord),
+                //},
             };
             return new[] { core };
         }
diff --git a/src/Orchard/Environment/DefaultOrchardHost.cs b/src/Orchard/Environment/DefaultOrchardHost.cs
index e2fb304b6..39287811b 100644
--- a/src/Orchard/Environment/DefaultOrchardHost.cs
+++ b/src/Orchard/Environment/DefaultOrchardHost.cs
@@ -6,6 +6,7 @@ using System.Collections.Generic;
 using Orchard.Environment.Configuration;
 using Orchard.Environment.Extensions;
 using Orchard.Environment.ShellBuilders;
+using Orchard.Logging;
 using Orchard.Mvc;
 using Orchard.Mvc.ViewEngines;
 using Orchard.Utility.Extensions;
@@ -29,13 +30,17 @@ namespace Orchard.Environment {
             _tenantManager = tenantManager;
             _shellContextFactory = shellContextFactory;
             _controllerBuilder = controllerBuilder;
+            Logger = NullLogger.Instance;
         }
 
+        public ILogger Logger { get; set; }
+
         public IList<ShellContext> Current {
             get { return BuildCurrent().ToReadOnlyCollection(); }
         }
 
         void IOrchardHost.Initialize() {
+            Logger.Information("Initializing");
             ViewEngines.Engines.Insert(0, LayoutViewEngine.CreateShim());
             _controllerBuilder.SetControllerFactory(new OrchardControllerFactory());
             ServiceLocator.SetLocator(t => _containerProvider.RequestLifetime.Resolve(t));
@@ -57,26 +62,40 @@ namespace Orchard.Environment {
         }
 
         IStandaloneEnvironment IOrchardHost.CreateStandaloneEnvironment(ShellSettings shellSettings) {
-            var shellContext = _shellContextFactory.Create(shellSettings);
+            Logger.Debug("Creating standalone environment for tenant {0}", shellSettings.Name);
+            var shellContext = CreateShellContext(shellSettings);
             return new StandaloneEnvironment(shellContext.LifetimeScope);
         }
 
-        IEnumerable<ShellContext> GetCurrent() {
-            lock (this) {
-                return _current ?? (_current = BuildCurrent());
-            }
-        }
 
         IEnumerable<ShellContext> BuildCurrent() {
-            return CreateAndActivate().ToArray();
+            lock (this) {
+                return _current ?? (_current = CreateAndActivate().ToArray());
+            }
         }
 
         IEnumerable<ShellContext> CreateAndActivate() {
-            foreach(var settings in _tenantManager.LoadSettings()) {
-                var context = _shellContextFactory.Create(settings);
-                context.Shell.Activate();
-                yield return context;
+            var allSettings = _tenantManager.LoadSettings();
+            if (allSettings.Any()) {
+                return allSettings.Select(
+                    settings => {
+                        var context = CreateShellContext(settings);
+                        context.Shell.Activate();
+                        return context;
+                    });
             }
+
+            return new[] {CreateSetupContext()};
+        }
+
+        ShellContext CreateSetupContext() {
+            Logger.Debug("Creating shell context for setup");
+            return _shellContextFactory.Create(null);
+        }
+
+        ShellContext CreateShellContext(ShellSettings settings) {
+            Logger.Debug("Creating shell context for tenant {0}", settings.Name);
+            return _shellContextFactory.Create(settings);
         }
 
         protected virtual void BeginRequest() {
@@ -99,7 +118,7 @@ namespace Orchard.Environment {
             finally {
                 containerProvider.EndRequestLifetime();
             }
-        }            
+        }
 
     }
 }
diff --git a/src/Orchard/Environment/HostContext.cs b/src/Orchard/Environment/HostContext.cs
deleted file mode 100644
index c3d519690..000000000
--- a/src/Orchard/Environment/HostContext.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-using System.Web.Mvc;
-using System.Web.Routing;
-
-namespace Orchard.Environment {
-    public class HostContext {
-        public ControllerBuilder ControllerBuilder { get; set; }
-        public RouteCollection Routes { get; set; }
-    }
-}
\ No newline at end of file
diff --git a/src/Orchard/Environment/OrchardStarter.cs b/src/Orchard/Environment/OrchardStarter.cs
index 676d2f865..8880e6eae 100644
--- a/src/Orchard/Environment/OrchardStarter.cs
+++ b/src/Orchard/Environment/OrchardStarter.cs
@@ -13,52 +13,71 @@ using Orchard.Environment.Extensions.Loaders;
 using Orchard.Environment.ShellBuilders;
 using Orchard.Environment.Topology;
 using Orchard.Events;
+using Orchard.Logging;
 
 namespace Orchard.Environment {
     public static class OrchardStarter {
         public static IContainer CreateHostContainer(Action<ContainerBuilder> registrations) {
             var builder = new ContainerBuilder();
+            builder.RegisterModule(new LoggingModule());
 
             // a single default host implementation is needed for bootstrapping a web app domain
-            builder.RegisterType<DefaultOrchardHost>().As<IOrchardHost>().SingleInstance();
-            builder.RegisterType<DefaultCompositionStrategy>().As<ICompositionStrategy_Obsolete>().SingleInstance();
-            builder.RegisterType<DefaultShellContainerFactory>().As<IShellContainerFactory>().SingleInstance();
-            builder.RegisterType<AppDataFolder>().As<IAppDataFolder>().SingleInstance();
-            builder.RegisterType<DefaultTenantManager>().As<ITenantManager>().SingleInstance();
-            builder.RegisterType<SafeModeShellContainerFactory>().As<IShellContainerFactory_Obsolete>().SingleInstance();
-            builder.RegisterType<DefaultTopologyDescriptorCache>().As<ITopologyDescriptorCache>().SingleInstance();
-
             builder.RegisterType<DefaultOrchardEventBus>().As<IEventBus>().SingleInstance();
+            builder.RegisterType<AppDataFolder>().As<IAppDataFolder>().SingleInstance();
+
+            builder.RegisterType<DefaultOrchardHost>().As<IOrchardHost>().SingleInstance();
+            {
+                builder.RegisterType<DefaultTenantManager>().As<ITenantManager>().SingleInstance();
+
+                builder.RegisterType<DefaultShellContextFactory>().As<IShellContextFactory>().SingleInstance();
+                {
+                    builder.RegisterType<DefaultTopologyDescriptorCache>().As<ITopologyDescriptorCache>().SingleInstance();
+
+                    builder.RegisterType<DefaultCompositionStrategy>()
+                        .As<ICompositionStrategy>()
+                        .As<ICompositionStrategy_Obsolete>()
+                        .SingleInstance();
+                    {
+                        builder.RegisterType<ExtensionManager>().As<IExtensionManager>().SingleInstance();
+                        {
+                            builder.RegisterType<ModuleFolders>().As<IExtensionFolders>()
+                                .WithParameter(new NamedParameter("paths", new[] { "~/Core", "~/Modules" }))
+                                .SingleInstance();
+                            builder.RegisterType<AreaFolders>().As<IExtensionFolders>()
+                                .WithParameter(new NamedParameter("paths", new[] { "~/Areas" }))
+                                .SingleInstance();
+                            builder.RegisterType<ThemeFolders>().As<IExtensionFolders>()
+                                .WithParameter(new NamedParameter("paths", new[] { "~/Core", "~/Themes" }))
+                                .SingleInstance();
+
+                            builder.RegisterType<AreaExtensionLoader>().As<IExtensionLoader>().SingleInstance();
+                            builder.RegisterType<CoreExtensionLoader>().As<IExtensionLoader>().SingleInstance();
+                            builder.RegisterType<ReferencedExtensionLoader>().As<IExtensionLoader>().SingleInstance();
+                            builder.RegisterType<PrecompiledExtensionLoader>().As<IExtensionLoader>().SingleInstance();
+                            builder.RegisterType<DynamicExtensionLoader>().As<IExtensionLoader>().SingleInstance();
+                        }
+                    }
+
+                    builder.RegisterType<DefaultShellContainerFactory>().As<IShellContainerFactory>().SingleInstance();
+                }
+            }
+
+            builder.RegisterType<DefaultOrchardShell>().As<IOrchardShell>().InstancePerMatchingLifetimeScope("shell");
 
             // The container provider gives you access to the lowest container at the time, 
             // and dynamically creates a per-request container. The EndRequestLifetime method
             // still needs to be called on end request, but that's the host component's job to worry about
             builder.RegisterType<ContainerProvider>().As<IContainerProvider>().InstancePerLifetimeScope();
 
-            builder.RegisterType<ExtensionManager>().As<IExtensionManager>().SingleInstance();
-            builder.RegisterType<AreaExtensionLoader>().As<IExtensionLoader>().SingleInstance();
-            builder.RegisterType<CoreExtensionLoader>().As<IExtensionLoader>().SingleInstance();
-            builder.RegisterType<ReferencedExtensionLoader>().As<IExtensionLoader>().SingleInstance();
-            builder.RegisterType<PrecompiledExtensionLoader>().As<IExtensionLoader>().SingleInstance();
-            builder.RegisterType<DynamicExtensionLoader>().As<IExtensionLoader>().SingleInstance();
 
-            builder.RegisterType<ModuleFolders>().As<IExtensionFolders>()
-                .WithParameter(new NamedParameter("paths", new[] { "~/Core", "~/Modules" }))
-                .SingleInstance();
-            builder.RegisterType<AreaFolders>().As<IExtensionFolders>()
-                .WithParameter(new NamedParameter("paths", new[] { "~/Areas" }))
-                .SingleInstance();
-            builder.RegisterType<ThemeFolders>().As<IExtensionFolders>()
-                .WithParameter(new NamedParameter("paths", new[] { "~/Core", "~/Themes" }))
-                .SingleInstance();
 
             registrations(builder);
 
-            
+
             var autofacSection = ConfigurationManager.GetSection(ConfigurationSettingsReader.DefaultSectionName);
             if (autofacSection != null)
                 builder.RegisterModule(new ConfigurationSettingsReader());
-            
+
             var optionalHostConfig = HostingEnvironment.MapPath("~/Config/Host.config");
             if (File.Exists(optionalHostConfig))
                 builder.RegisterModule(new ConfigurationSettingsReader(ConfigurationSettingsReader.DefaultSectionName, optionalHostConfig));
diff --git a/src/Orchard/Environment/ShellBuilders/DefaultShellContextFactory.cs b/src/Orchard/Environment/ShellBuilders/DefaultShellContextFactory.cs
index 00eec8608..2438788c6 100644
--- a/src/Orchard/Environment/ShellBuilders/DefaultShellContextFactory.cs
+++ b/src/Orchard/Environment/ShellBuilders/DefaultShellContextFactory.cs
@@ -1,7 +1,11 @@
+using System;
+using System.Linq;
 using Autofac;
 using Orchard.Environment.Configuration;
+using Orchard.Environment.Extensions.Models;
 using Orchard.Environment.Topology;
 using Orchard.Environment.Topology.Models;
+using Orchard.Logging;
 
 namespace Orchard.Environment.ShellBuilders {
     public class DefaultShellContextFactory : IShellContextFactory {
@@ -16,30 +20,70 @@ namespace Orchard.Environment.ShellBuilders {
             _topologyDescriptorCache = topologyDescriptorCache;
             _compositionStrategy = compositionStrategy;
             _shellContainerFactory = shellContainerFactory;
+            Logger = NullLogger.Instance;
         }
 
+        public ILogger Logger { get; set; }
+
         public ShellContext Create(ShellSettings settings) {
-            var cachedTopology = _topologyDescriptorCache.Fetch(settings.Name);
-            // handle null-(e.g. cache miss)
-
-            var topology = _compositionStrategy.Compose(cachedTopology);
-            var shellScope = _shellContainerFactory.CreateContainer(topology);
-
-            ShellTopologyDescriptor currentTopology;
-            using (var standaloneEnvironment = new StandaloneEnvironment(shellScope)) {
-                var topologyDescriptorProvider = standaloneEnvironment.Resolve<ITopologyDescriptorManager>();
-                currentTopology = topologyDescriptorProvider.GetTopologyDescriptor();
+            if (settings == null) {
+                return CreateSetupContext();
             }
 
-            if (cachedTopology.SerialNumber != currentTopology.SerialNumber) {
-                _topologyDescriptorCache.Store(settings.Name, currentTopology);
-                topology = _compositionStrategy.Compose(currentTopology);
+            Logger.Debug("Creating shell context for tenant {0}", settings.Name);
+
+            var cachedDescriptor = _topologyDescriptorCache.Fetch(settings.Name);
+            if (cachedDescriptor == null) {
+                Logger.Information("No topology cached. Starting with minimum components.");
+                cachedDescriptor = new ShellTopologyDescriptor {
+                    SerialNumber = 0,
+                    EnabledFeatures = Enumerable.Empty<TopologyFeature>(),
+                    Parameters = Enumerable.Empty<TopologyParameter>(),
+                };
+            }
+            // handle null-(e.g. cache miss)
+
+            var topology = _compositionStrategy.Compose(cachedDescriptor);
+            var shellScope = _shellContainerFactory.CreateContainer(topology);
+
+            ShellTopologyDescriptor currentDescriptor;
+            using (var standaloneEnvironment = new StandaloneEnvironment(shellScope)) {
+                var topologyDescriptorProvider = standaloneEnvironment.Resolve<ITopologyDescriptorManager>();
+                currentDescriptor = topologyDescriptorProvider.GetTopologyDescriptor();
+            }
+
+            if (cachedDescriptor.SerialNumber != currentDescriptor.SerialNumber) {
+                Logger.Information("Newer topology obtained. Rebuilding shell container.");
+
+                _topologyDescriptorCache.Store(settings.Name, currentDescriptor);
+                topology = _compositionStrategy.Compose(currentDescriptor);
                 shellScope = _shellContainerFactory.CreateContainer(topology);
             }
 
             return new ShellContext {
                 Settings = settings,
-                TopologyDescriptor = currentTopology,
+                TopologyDescriptor = currentDescriptor,
+                Topology = topology,
+                LifetimeScope = shellScope,
+                Shell = shellScope.Resolve<IOrchardShell>(),
+            };
+        }
+
+        private ShellContext CreateSetupContext() {
+            Logger.Warning("No shell settings available. Creating shell context for setup");
+
+            var settings = new ShellSettings { Name = "__Orchard__Setup__" };
+            var descriptor = new ShellTopologyDescriptor {
+                SerialNumber = -1,
+                EnabledFeatures = new[] { new TopologyFeature { Name = "Orchard.Setup" } },
+            };
+
+            var topology = _compositionStrategy.Compose(descriptor);
+            var shellScope = _shellContainerFactory.CreateContainer(topology);
+
+            return new ShellContext {
+                Settings = settings,
+                TopologyDescriptor = descriptor,
                 Topology = topology,
                 LifetimeScope = shellScope,
                 Shell = shellScope.Resolve<IOrchardShell>(),
diff --git a/src/Orchard/Environment/Topology/Models/ShellTopologyDescriptor.cs b/src/Orchard/Environment/Topology/Models/ShellTopologyDescriptor.cs
index 59736fd51..dd93919b2 100644
--- a/src/Orchard/Environment/Topology/Models/ShellTopologyDescriptor.cs
+++ b/src/Orchard/Environment/Topology/Models/ShellTopologyDescriptor.cs
@@ -1,7 +1,13 @@
 using System.Collections.Generic;
+using System.Linq;
 
 namespace Orchard.Environment.Topology.Models {
     public class ShellTopologyDescriptor {
+        public ShellTopologyDescriptor() {
+            EnabledFeatures = Enumerable.Empty<TopologyFeature>();
+            Parameters = Enumerable.Empty<TopologyParameter>();
+        }
+
         public int SerialNumber { get; set; }
         public IEnumerable<TopologyFeature> EnabledFeatures { get; set; }
         public IEnumerable<TopologyParameter> Parameters { get; set; }
diff --git a/src/Orchard/Orchard.Framework.csproj b/src/Orchard/Orchard.Framework.csproj
index a28eb0af7..bcb51f945 100644
--- a/src/Orchard/Orchard.Framework.csproj
+++ b/src/Orchard/Orchard.Framework.csproj
@@ -126,7 +126,6 @@
     <Compile Include="Environment\DefaultCompositionStrategy.cs" />
     <Compile Include="Environment\DefaultOrchardHost.cs" />
     <Compile Include="Mvc\OrchardControllerFactory.cs" />
-    <Compile Include="Environment\HostContext.cs" />
     <Compile Include="Environment\IOrchardHost.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Validation\Argument.cs" />