clean up IGListExperimentDeferredToObjectCreation

Summary: Experiment shipped. Reviewed By: Haud, lorixx Differential Revision: D22219240 fbshipit-source-id: 9299d1371b87593fcbece4557cf760cb9c42e1fe
Instagram · Jun 26, 2020 · 7fc4384 · 7fc4384
1 parent 34c935c
commit 7fc4384
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 18 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -10,6 +10,10 @@ The changelog for `IGListKit`. Also see the [releases](https://github.com/instag
 
 - Added `APPLICATION_EXTENSION_API_ONLY` support for `IGListDiffKit` [Peter Meyers](https://github.com/pm-dev) [(#1422)](https://github.com/Instagram/IGListKit/pull/1422)
 
+### Enhancements
+
+-  Improved performance by deferring requesting objects from the `IGListAdapterDataSource` until just before diffing is executed. If n updates are coalesced into one, this results in just a single request for objects from the data source. Shipped with experiment `IGListExperimentDeferredToObjectCreation` from Ryan Nystrom.  [Maxime Ollivier](https://github.com/maxolls) (tbd)
+
 ### Fixes
 
 - `IGListCollectionViewLayout` should get the section/index counts via `UICollectionView` to stay in sync, instead of the `dataSource` [Maxime Ollivier](https://github.com/maxolls) (tbd)

diff --git a/Source/IGListDiffKit/IGListExperiments.h b/Source/IGListDiffKit/IGListExperiments.h
@@ -20,10 +20,8 @@ typedef NS_OPTIONS (NSInteger, IGListExperiment) {
     IGListExperimentBackgroundDiffing = 1 << 2,
     /// Test fallback to reloadData when "too many" update operations.
     IGListExperimentReloadDataFallback = 1 << 3,
-    /// Test deferring object creation until just before diffing.
-    IGListExperimentDeferredToObjectCreation = 1 << 4,
     /// Test invalidating layout when cell reloads/updates in IGListBindingSectionController.
-    IGListExperimentInvalidateLayoutForUpdates = 1 << 5,
+    IGListExperimentInvalidateLayoutForUpdates = 1 << 4,
 };
 
 /**

diff --git a/Source/IGListKit/IGListAdapter.m b/Source/IGListKit/IGListAdapter.m
@@ -324,22 +324,14 @@ - (void)performUpdatesAnimated:(BOOL)animated completion:(IGListUpdaterCompletio
 
     NSArray *fromObjects = self.sectionMap.objects;
 
-    IGListToObjectBlock toObjectsBlock;
     __weak __typeof__(self) weakSelf = self;
-    if (IGListExperimentEnabled(self.experiments, IGListExperimentDeferredToObjectCreation)) {
-        toObjectsBlock = ^NSArray *{
-            __typeof__(self) strongSelf = weakSelf;
-            if (strongSelf == nil) {
-                return nil;
-            }
-            return [dataSource objectsForListAdapter:strongSelf];
-        };
-    } else {
-        NSArray *newObjects = [dataSource objectsForListAdapter:self];
-        toObjectsBlock = ^NSArray *{
-            return newObjects;
-        };
-    }
+    IGListToObjectBlock toObjectsBlock = ^NSArray *{
+        __typeof__(self) strongSelf = weakSelf;
+        if (strongSelf == nil) {
+            return nil;
+        }
+        return [dataSource objectsForListAdapter:strongSelf];
+    };
 
     [self _enterBatchUpdates];
     [self.updater performUpdateWithCollectionViewBlock:[self _collectionViewBlock]