Port v7@2aa0dfb2c5 - WIP

src/Umbraco.Web/PublishedCache/XmlPublishedCache/PublishedContentCache.cs

@@ -486,7 +486,12 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
             // not trying to be thread-safe here, that's not the point
 
             if (preview == false)
+            {
+                // if there's a current enlisted reader/writer, use its xml
+                var tempXml = _xmlStore.TempXml;
+                if (tempXml != null) return tempXml;
                 return _xml;
+            }
 
             // Xml cache does not support retrieving preview content when not previewing
             if (_previewContent == null)

src/Umbraco.Web/PublishedCache/XmlPublishedCache/PublishedMediaCache.cs

@@ -108,7 +108,43 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
 
         public override IEnumerable<IPublishedContent> GetAtRoot(bool preview)
         {
-            //TODO: We should be able to look these ids first in Examine!
+            var searchProvider = GetSearchProviderSafe();
+
+            if (searchProvider != null)
+            {
+                try
+                {
+                    // first check in Examine for the cache values
+                    // +(+parentID:-1) +__IndexType:media
+
+                    var criteria = searchProvider.CreateSearchCriteria("media");
+                    var filter = criteria.ParentId(-1).Not().Field(UmbracoContentIndexer.IndexPathFieldName, "-1,-21,".MultipleCharacterWildcard());
+
+                    var result = searchProvider.Search(filter.Compile());
+                    if (result != null)
+                        return result.Select(x => CreateFromCacheValues(ConvertFromSearchResult(x)));
+                }
+                catch (Exception ex)
+                {
+                    if (ex is FileNotFoundException)
+                    {
+                        //Currently examine is throwing FileNotFound exceptions when we have a loadbalanced filestore and a node is published in umbraco
+                        //See this thread: http://examine.cdodeplex.com/discussions/264341
+                        //Catch the exception here for the time being, and just fallback to GetMedia
+                        //TODO: Need to fix examine in LB scenarios!
+                        Current.Logger.Error<PublishedMediaCache>("Could not load data from Examine index for media", ex);
+                    }
+                    else if (ex is AlreadyClosedException)
+                    {
+                        //If the app domain is shutting down and the site is under heavy load the index reader will be closed and it really cannot
+                        //be re-opened since the app domain is shutting down. In this case we have no option but to try to load the data from the db.
+                        Current.Logger.Error<PublishedMediaCache>("Could not load data from Examine index for media, the app domain is most likely in a shutdown state", ex);
+                    }
+                    else throw;
+                }
+            }
+
+            //something went wrong, fetch from the db
 
             var rootMedia = _mediaService.GetRootMedia();
             return rootMedia.Select(m => GetUmbracoMedia(m.Id));

src/Umbraco.Web/PublishedCache/XmlPublishedCache/SafeXmlReaderWriter.cs

@@ -17,6 +17,11 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
         private bool _using;
         private bool _registerXmlChange;
 
+        // the default enlist priority is 100
+        // enlist with a lower priority to ensure that anything "default" has a clean xml
+        private const int EnlistPriority = 60;
+        private const string EnlistKey = "safeXmlReaderWriter";
+
         private SafeXmlReaderWriter(IDisposable releaser, XmlDocument xml, Action<XmlDocument> refresh, Action<XmlDocument, bool> apply, bool isWriter, bool scoped)
         {
             _releaser = releaser;
@@ -29,6 +34,12 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
             _xml = IsWriter ? Clone(xml) : xml;
         }
 
+        public static SafeXmlReaderWriter Get(IScopeProvider scopeProvider)
+        {
+            var scopeContext = scopeProvider.Context;
+            return scopeContext?.GetEnlisted<SafeXmlReaderWriter>(EnlistKey);
+        }
+
         public static SafeXmlReaderWriter Get(IScopeProvider scopeProvider, AsyncLock xmlLock, XmlDocument xml, Action<XmlDocument> refresh, Action<XmlDocument, bool> apply, bool writer)
         {
             var scopeContext = scopeProvider.Context;
@@ -42,7 +53,7 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
             }
 
             // get or create an enlisted reader/writer
-            var rw = scopeContext.Enlist("safeXmlReaderWriter",
+            var rw = scopeContext.Enlist(EnlistKey,
                 () => // creator
                 {
                     // obtain exclusive access to xml and create reader/writer
@@ -52,7 +63,7 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
                 (completed, item) => // action
                 {
                     item.DisposeForReal(completed);
-                });
+                }, EnlistPriority);
 
             // ensure it's not already in-use - should never happen, just being super safe
             if (rw._using)

src/Umbraco.Web/PublishedCache/XmlPublishedCache/XmlStore.cs

@@ -38,7 +38,7 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
     /// then passed to all <see cref="PublishedContentCache"/> instances that are created (one per request).</para>
     /// <para>This class should *not* be public.</para>
     /// </remarks>
-    class XmlStore : IDisposable
+    internal class XmlStore : IDisposable
     {
         private readonly IDocumentRepository _documentRepository;
         private readonly IMediaRepository _mediaRepository;
@@ -329,6 +329,9 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
             }
         }
 
+        // Gets the temp. Xml managed by SafeXmlReaderWrite, if any
+        public XmlDocument TempXml => SafeXmlReaderWriter.Get(_scopeProvider)?.Xml;
+
         // assumes xml lock
         private void SetXmlLocked(XmlDocument xml, bool registerXmlChange)
         {