From 65db8d7f072cc86d6a51588ffa1750bd83c23adc Mon Sep 17 00:00:00 2001
From: Louis DeJardin <Louis.DeJardin@microsoft.com>
Date: Sun, 16 May 2010 18:40:15 -0700
Subject: [PATCH] Perf: lazy-loading for ContentPart<TRecord>.Record property

Content item parts that are not referenced do not need to acquire their data

--HG--
branch : dev
---
 src/Orchard/ContentManagement/ContentPart.cs  |  5 +++-
 .../Handlers/StorageFilter.cs                 | 27 +++++++++----------
 .../Handlers/StorageVersionFilter.cs          | 13 ++++-----
 src/Orchard/Orchard.Framework.csproj          |  1 +
 4 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/src/Orchard/ContentManagement/ContentPart.cs b/src/Orchard/ContentManagement/ContentPart.cs
index 1b56b8fc1..180ea362f 100644
--- a/src/Orchard/ContentManagement/ContentPart.cs
+++ b/src/Orchard/ContentManagement/ContentPart.cs
@@ -1,10 +1,13 @@
+using Orchard.ContentManagement.Utilities;
+
 namespace Orchard.ContentManagement {
     public abstract class ContentPart : IContent {
         public virtual ContentItem ContentItem { get; set; }
     }
 
     public class ContentPart<TRecord> : ContentPart {
-        public TRecord Record { get; set; }
+        public readonly LazyField<TRecord> _record = new LazyField<TRecord>();
+        public TRecord Record { get { return _record.Value; } set { _record.Value = value; } }
     }
 
 }
diff --git a/src/Orchard/ContentManagement/Handlers/StorageFilter.cs b/src/Orchard/ContentManagement/Handlers/StorageFilter.cs
index 2abdc5efe..b6411f730 100644
--- a/src/Orchard/ContentManagement/Handlers/StorageFilter.cs
+++ b/src/Orchard/ContentManagement/Handlers/StorageFilter.cs
@@ -26,6 +26,16 @@ namespace Orchard.ContentManagement.Handlers {
             _repository = repository;
         }
 
+        protected virtual TRecord GetRecordCore(ContentItemVersionRecord versionRecord) {
+            return _repository.Get(versionRecord.ContentItemRecord.Id);
+        }
+
+        protected virtual TRecord CreateRecordCore(ContentItemVersionRecord versionRecord, TRecord record) {
+            record.ContentItemRecord = versionRecord.ContentItemRecord;
+            _repository.Create(record);
+            return record;
+        }
+
         protected override void Activated(ActivatedContentContext context, ContentPart<TRecord> instance) {
             if (instance.Record != null) {
                 throw new InvalidOperationException(string.Format(
@@ -36,23 +46,12 @@ namespace Orchard.ContentManagement.Handlers {
         }
 
         protected override void Creating(CreateContentContext context, ContentPart<TRecord> instance) {
-            instance.Record.ContentItemRecord = context.ContentItemRecord;
-            _repository.Create(instance.Record);
-        }
-
-        protected virtual TRecord GetRecord(LoadContentContext context) {
-            return _repository.Get(context.Id);
+            CreateRecordCore(context.ContentItemVersionRecord, instance.Record);
         }
 
         protected override void Loading(LoadContentContext context, ContentPart<TRecord> instance) {
-            var record = GetRecord(context);
-            if (record != null) {
-                instance.Record = record;
-            }
-            else {
-                var createContext = new CreateContentContext(context.ContentItem);
-                Creating(createContext, instance);
-            }
+            var versionRecord = context.ContentItemVersionRecord;
+            instance._record.Loader(prior => GetRecordCore(versionRecord) ?? CreateRecordCore(versionRecord, prior));
         }
 
         protected override void Versioning(VersionContentContext context, ContentPart<TRecord> existing, ContentPart<TRecord> building) {
diff --git a/src/Orchard/ContentManagement/Handlers/StorageVersionFilter.cs b/src/Orchard/ContentManagement/Handlers/StorageVersionFilter.cs
index e7247fd4a..2ac987351 100644
--- a/src/Orchard/ContentManagement/Handlers/StorageVersionFilter.cs
+++ b/src/Orchard/ContentManagement/Handlers/StorageVersionFilter.cs
@@ -7,14 +7,15 @@ namespace Orchard.ContentManagement.Handlers {
             : base(repository) {
         }
 
-        protected override TRecord GetRecord(LoadContentContext context) {
-            return _repository.Get(context.ContentItemVersionRecord.Id);
+        protected override TRecord GetRecordCore(ContentItemVersionRecord versionRecord) {
+            return _repository.Get(versionRecord.Id);
         }
 
-        protected override void Creating(CreateContentContext context, ContentPart<TRecord> instance) {
-            instance.Record.ContentItemRecord = context.ContentItemRecord;
-            instance.Record.ContentItemVersionRecord = context.ContentItemVersionRecord;
-            _repository.Create(instance.Record);
+        protected override TRecord CreateRecordCore(ContentItemVersionRecord versionRecord, TRecord record) {
+            record.ContentItemRecord = versionRecord.ContentItemRecord;
+            record.ContentItemVersionRecord = versionRecord;
+            _repository.Create(record);
+            return record;
         }
 
         protected override void Versioning(VersionContentContext context, ContentPart<TRecord> existing, ContentPart<TRecord> building) {
diff --git a/src/Orchard/Orchard.Framework.csproj b/src/Orchard/Orchard.Framework.csproj
index 10028f1dc..62227f8d3 100644
--- a/src/Orchard/Orchard.Framework.csproj
+++ b/src/Orchard/Orchard.Framework.csproj
@@ -152,6 +152,7 @@
     <Compile Include="Caching\Weak.cs" />
     <Compile Include="ContentManagement\DefaultContentManagerSession.cs" />
     <Compile Include="ContentManagement\IContentManagerSession.cs" />
+    <Compile Include="ContentManagement\Utilities\LazyField.cs" />
     <Compile Include="FileSystems\WebSite\WebSiteFolder.cs" />
     <Compile Include="FileSystems\AppData\IAppDataFolder.cs" />
     <Compile Include="FileSystems\WebSite\IWebSiteFolder.cs" />