U4-7813 Enable MiniProfiler to profiler during startup

Conflicts:
	src/Umbraco.Core/Umbraco.Core.csproj

src/Umbraco.Core/Profiling/StartupWebProfilerProvider.cs

@@ -0,0 +1,126 @@
+using System.Threading;
+using System.Web;
+using StackExchange.Profiling;
+
+namespace Umbraco.Core.Profiling
+{
+    /// <summary>
+    /// Allows us to profile items during app startup - before an HttpRequest is created
+    /// </summary>
+    internal class StartupWebProfilerProvider : WebRequestProfilerProvider
+    {
+        public StartupWebProfilerProvider()
+        {
+            _startupPhase = StartupPhase.Boot;
+            //create the startup profiler
+            _startupProfiler = new MiniProfiler("http://localhost/umbraco-startup", ProfileLevel.Verbose)
+            {
+                Name = "StartupProfiler"
+            };            
+        }
+
+        private MiniProfiler _startupProfiler;
+        private readonly ReaderWriterLockSlim _locker = new ReaderWriterLockSlim();
+
+        private enum StartupPhase
+        {
+            None = 0,
+            Boot = 1,
+            Request = 2
+        }
+
+        private volatile StartupPhase _startupPhase;
+
+        public void BootComplete()
+        {
+            using (new ReadLock(_locker))
+            {
+                if (_startupPhase != StartupPhase.Boot) return;
+            }
+
+            using (var l = new UpgradeableReadLock(_locker))
+            {
+                if (_startupPhase == StartupPhase.Boot)
+                {
+                    l.UpgradeToWriteLock();
+
+                    ////Now we need to transfer some information from our startup phase to the normal
+                    ////web request phase to output the startup profiled information.
+                    ////Stop our internal startup profiler, this will write out it's results to storage.
+                    //StopProfiler(_startupProfiler);
+                    //SaveProfiler(_startupProfiler);
+
+                    _startupPhase = StartupPhase.Request;
+                }
+            }
+        }        
+
+        public override void Stop(bool discardResults)
+        {
+            using (new ReadLock(_locker))
+            {
+                if (_startupPhase == StartupPhase.None)
+                {
+                    base.Stop(discardResults);
+                    return;
+                }
+            }
+
+            using (var l = new UpgradeableReadLock(_locker))
+            {
+                if (_startupPhase > 0 && base.GetCurrentProfiler() == null)
+                {
+                    l.UpgradeToWriteLock();
+
+                    _startupPhase = StartupPhase.None;                    
+
+                    if (HttpContext.Current != null)
+                    {
+                        HttpContext.Current.Items[":mini-profiler:"] = _startupProfiler;
+                        base.Stop(discardResults);
+                        _startupProfiler = null;
+                    }
+                }
+                else
+                {
+                    base.Stop(discardResults);
+                }
+            }
+        }
+
+        public override MiniProfiler Start(ProfileLevel level)
+        {
+            using (new ReadLock(_locker))
+            {
+                if (_startupPhase > 0 && base.GetCurrentProfiler() == null)
+                {
+                    SetProfilerActive(_startupProfiler);
+                    return _startupProfiler;
+                }
+
+                return base.Start(level);
+            }
+        }
+
+        public override MiniProfiler GetCurrentProfiler()
+        {
+            using (new ReadLock(_locker))
+            {
+                if (_startupPhase > 0)
+                {
+                    try
+                    {
+                        var current = base.GetCurrentProfiler();
+                        if (current == null) return _startupProfiler;
+                    }
+                    catch
+                    {
+                        return _startupProfiler;
+                    }
+                }
+
+                return base.GetCurrentProfiler();
+            }
+        }
+    }
+}

src/Umbraco.Core/Profiling/WebProfiler.cs

@@ -12,15 +12,24 @@ namespace Umbraco.Core.Profiling
     /// </summary>
     internal class WebProfiler : IProfiler
     {
+        private StartupWebProfilerProvider _startupWebProfilerProvider;
 
         /// <summary>
         /// Constructor
-        /// </summary>
-        /// <remarks>
-        /// Binds to application events to enable the MiniProfiler
-        /// </remarks>
+        /// </summary>        
         internal WebProfiler()
         {
+            //setup some defaults
+            MiniProfiler.Settings.SqlFormatter = new SqlServerFormatter();
+            MiniProfiler.Settings.StackMaxLength = 5000;
+
+            //At this point we know that we've been constructed during app startup, there won't be an HttpRequest in the HttpContext 
+            // since it hasn't started yet. So we need to do some hacking to enable profiling during startup.
+            _startupWebProfilerProvider = new StartupWebProfilerProvider();
+            //this should always be the case during startup, we'll need to set a custom profiler provider
+            MiniProfiler.Settings.ProfilerProvider = _startupWebProfilerProvider;
+
+            //Binds to application events to enable the MiniProfiler with a real HttpRequest
             UmbracoApplicationBase.ApplicationInit += UmbracoApplicationApplicationInit;
         }
 
@@ -53,7 +62,12 @@ namespace Umbraco.Core.Profiling
         /// <param name="e"></param>
         void UmbracoApplicationEndRequest(object sender, EventArgs e)
         {
-            if (CanPerformProfilingAction(sender))
+            if (_startupWebProfilerProvider != null)
+            {
+                Stop();
+                _startupWebProfilerProvider = null;
+            }
+            else if (CanPerformProfilingAction(sender))
             {
                 Stop();
             }
@@ -66,6 +80,11 @@ namespace Umbraco.Core.Profiling
         /// <param name="e"></param>
         void UmbracoApplicationBeginRequest(object sender, EventArgs e)
         {
+            if (_startupWebProfilerProvider != null)
+            {
+                _startupWebProfilerProvider.BootComplete();
+            }
+
             if (CanPerformProfilingAction(sender))
             {
                 Start();
@@ -124,9 +143,7 @@ namespace Umbraco.Core.Profiling
         /// Start the profiler
         /// </summary>
         public void Start()
-        {
-            MiniProfiler.Settings.SqlFormatter = new SqlServerFormatter();
-            MiniProfiler.Settings.StackMaxLength = 5000;
+        {            
             MiniProfiler.Start();
         }