Beter table/collection update history (facebookarchive#2562)

- Introduce thread-safe ASEventLog
- ASCollectionNode and ASTableNode share their event log with their ASDataController. The controller uses it to log change set submitting and finishing events.
- ASCollectionNode and ASTableNode print their data source and delegate in their debug description.

Author: nguyenhuy

AsyncDisplayKit.xcodeproj/project.pbxproj

@@ -486,6 +486,10 @@
 		E52405B31C8FEF03004DC8E7 /* ASLayoutTransition.mm in Sources */ = {isa = PBXBuildFile; fileRef = E52405B21C8FEF03004DC8E7 /* ASLayoutTransition.mm */; };
 		E55D86321CA8A14000A0C26F /* ASLayoutElement.mm in Sources */ = {isa = PBXBuildFile; fileRef = E55D86311CA8A14000A0C26F /* ASLayoutElement.mm */; };
 		E55D86331CA8A14000A0C26F /* ASLayoutElement.mm in Sources */ = {isa = PBXBuildFile; fileRef = E55D86311CA8A14000A0C26F /* ASLayoutElement.mm */; };
+		E55FFC8F1DCCA50700060AC4 /* ASEventLog.h in Headers */ = {isa = PBXBuildFile; fileRef = E55FFC8E1DCCA50700060AC4 /* ASEventLog.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		E55FFC911DCCA5A600060AC4 /* ASEventLog.mm in Sources */ = {isa = PBXBuildFile; fileRef = E55FFC901DCCA5A600060AC4 /* ASEventLog.mm */; };
+		E55FFC921DCCA5A600060AC4 /* ASEventLog.mm in Sources */ = {isa = PBXBuildFile; fileRef = E55FFC901DCCA5A600060AC4 /* ASEventLog.mm */; };
+		E55FFC931DCCB0A800060AC4 /* ASEventLog.h in CopyFiles */ = {isa = PBXBuildFile; fileRef = E55FFC8E1DCCA50700060AC4 /* ASEventLog.h */; };
 		E5711A2C1C840C81009619D4 /* ASIndexedNodeContext.h in Headers */ = {isa = PBXBuildFile; fileRef = E5711A2A1C840C81009619D4 /* ASIndexedNodeContext.h */; };
 		E5711A2E1C840C96009619D4 /* ASIndexedNodeContext.mm in Sources */ = {isa = PBXBuildFile; fileRef = E5711A2D1C840C96009619D4 /* ASIndexedNodeContext.mm */; };
 		E5711A301C840C96009619D4 /* ASIndexedNodeContext.mm in Sources */ = {isa = PBXBuildFile; fileRef = E5711A2D1C840C96009619D4 /* ASIndexedNodeContext.mm */; };
@@ -658,6 +662,7 @@
 			dstPath = "include/$(PRODUCT_NAME)";
 			dstSubfolderSpec = 16;
 			files = (
+				E55FFC931DCCB0A800060AC4 /* ASEventLog.h in CopyFiles */,
 				693117CE1DC7C72700DE4784 /* ASDisplayNode+Deprecated.h in CopyFiles */,
 				69F381A51DA4630D00CF2278 /* NSArray+Diffing.h in CopyFiles */,
 				CC4C2A7A1D8902350039ACAB /* ASTraceEvent.h in CopyFiles */,
@@ -1168,6 +1173,8 @@
 		E52405B21C8FEF03004DC8E7 /* ASLayoutTransition.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASLayoutTransition.mm; sourceTree = "<group>"; };
 		E52405B41C8FEF16004DC8E7 /* ASLayoutTransition.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASLayoutTransition.h; sourceTree = "<group>"; };
 		E55D86311CA8A14000A0C26F /* ASLayoutElement.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; name = ASLayoutElement.mm; path = AsyncDisplayKit/Layout/ASLayoutElement.mm; sourceTree = "<group>"; };
+		E55FFC8E1DCCA50700060AC4 /* ASEventLog.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASEventLog.h; sourceTree = "<group>"; };
+		E55FFC901DCCA5A600060AC4 /* ASEventLog.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASEventLog.mm; sourceTree = "<group>"; };
 		E5711A2A1C840C81009619D4 /* ASIndexedNodeContext.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASIndexedNodeContext.h; sourceTree = "<group>"; };
 		E5711A2D1C840C96009619D4 /* ASIndexedNodeContext.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASIndexedNodeContext.mm; sourceTree = "<group>"; };
 		EFA731F0396842FF8AB635EE /* libPods-AsyncDisplayKitTests.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-AsyncDisplayKitTests.a"; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -1583,6 +1590,8 @@
 				6959433C1D70815300B0EE1F /* ASDisplayNodeLayout.mm */,
 				69E100691CA89CB600D88C1B /* ASEnvironmentInternal.h */,
 				69E1006A1CA89CB600D88C1B /* ASEnvironmentInternal.mm */,
+				E55FFC8E1DCCA50700060AC4 /* ASEventLog.h */,
+				E55FFC901DCCA5A600060AC4 /* ASEventLog.mm */,
 				68B8A4DB1CBD911D007E4543 /* ASImageNode+AnimatedImagePrivate.h */,
 				058D0A0D195D050800B7D73C /* ASImageNode+CGExtras.h */,
 				058D0A0E195D050800B7D73C /* ASImageNode+CGExtras.m */,
@@ -1765,6 +1774,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				E55FFC8F1DCCA50700060AC4 /* ASEventLog.h in Headers */,
 				683489281D70DE3400327501 /* ASDisplayNode+Deprecated.h in Headers */,
 				6907C2581DC4ECFE00374C66 /* ASObjectDescriptionHelpers.h in Headers */,
 				69E0E8A71D356C9400627613 /* ASEqualityHelpers.h in Headers */,
@@ -2235,6 +2245,7 @@
 				E5711A2E1C840C96009619D4 /* ASIndexedNodeContext.mm in Sources */,
 				9C8221971BA237B80037F19A /* ASStackBaselinePositionedLayout.mm in Sources */,
 				251B8EF81BBB3D690087C538 /* ASCollectionDataController.mm in Sources */,
+				E55FFC911DCCA5A600060AC4 /* ASEventLog.mm in Sources */,
 				ACF6ED301B17843500DA7C62 /* ASStackLayoutSpec.mm in Sources */,
 				257754BE1BEE458E00737CA5 /* ASTextKitComponents.m in Sources */,
 				257754A91BEE44CD00737CA5 /* ASTextKitContext.mm in Sources */,
@@ -2422,6 +2433,7 @@
 				254C6B851BF94F8A003EC431 /* ASTextKitAttributes.mm in Sources */,
 				509E68601B3AED8E009B9150 /* ASScrollDirection.m in Sources */,
 				B35062091B010EFD0018CF92 /* ASScrollNode.m in Sources */,
+				E55FFC921DCCA5A600060AC4 /* ASEventLog.mm in Sources */,
 				9C8221981BA237B80037F19A /* ASStackBaselinePositionedLayout.mm in Sources */,
 				8BDA5FC81CDBDF95007D13B2 /* ASVideoPlayerNode.mm in Sources */,
 				34EFC7721B701D0300AD841F /* ASStackLayoutSpec.mm in Sources */,

AsyncDisplayKit/ASCollectionNode.mm

@@ -13,6 +13,7 @@
 #import "ASCollectionInternal.h"
 #import "ASCollectionViewLayoutFacilitatorProtocol.h"
 #import "ASCollectionNode.h"
+#import "ASDisplayNodeInternal.h"
 #import "ASDisplayNode+Subclasses.h"
 #import "ASEnvironmentInternal.h"
 #import "ASInternalHelpers.h"
@@ -121,7 +122,7 @@ - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionVi
 - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator
 {
   ASDisplayNodeViewBlock collectionViewBlock = ^UIView *{
-    return [[ASCollectionView alloc] _initWithFrame:frame collectionViewLayout:layout layoutFacilitator:layoutFacilitator];
+    return [[ASCollectionView alloc] _initWithFrame:frame collectionViewLayout:layout layoutFacilitator:layoutFacilitator eventLog:ASDisplayNodeGetEventLog(self)];
   };
 
   if (self = [super initWithViewBlock:collectionViewBlock]) {
@@ -561,4 +562,14 @@ - (void)updateCurrentRangeWithMode:(ASLayoutRangeMode)rangeMode;
 
 ASEnvironmentCollectionTableSetEnvironmentState(_environmentStateLock)
 
+#pragma mark - Debugging (Private)
+
+- (NSMutableArray<NSDictionary *> *)propertiesForDebugDescription
+{
+  NSMutableArray<NSDictionary *> *result = [super propertiesForDebugDescription];
+  [result addObject:@{ @"dataSource" : ASObjectDescriptionMakeTiny(self.dataSource) }];
+  [result addObject:@{ @"delegate" : ASObjectDescriptionMakeTiny(self.delegate) }];
+  return result;
+}
+
 @end

AsyncDisplayKit/ASCollectionView.mm

@@ -244,10 +244,10 @@ - (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout *)layout
 
 - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout
 {
-  return [self _initWithFrame:frame collectionViewLayout:layout layoutFacilitator:nil];
+  return [self _initWithFrame:frame collectionViewLayout:layout layoutFacilitator:nil eventLog:nil];
 }
 
-- (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator
+- (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout layoutFacilitator:(id<ASCollectionViewLayoutFacilitatorProtocol>)layoutFacilitator eventLog:(ASEventLog *)eventLog
 {
   if (!(self = [super initWithFrame:frame collectionViewLayout:layout]))
     return nil;
@@ -259,7 +259,7 @@ - (instancetype)_initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionV
   _rangeController.delegate = self;
   _rangeController.layoutController = _layoutController;
 
-  _dataController = [[ASCollectionDataController alloc] initWithDataSource:self];
+  _dataController = [[ASCollectionDataController alloc] initWithDataSource:self eventLog:eventLog];
   _dataController.delegate = _rangeController;
   _dataController.environmentDelegate = self;
 

AsyncDisplayKit/ASDisplayNode+Beta.h

@@ -10,7 +10,7 @@
 
 #import "ASDisplayNode.h"
 #import "ASLayoutRangeType.h"
-#import "ASTraceEvent.h"
+#import "ASEventLog.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -19,18 +19,16 @@ void ASPerformBlockOnMainThread(void (^block)());
 void ASPerformBlockOnBackgroundThread(void (^block)()); // DISPATCH_QUEUE_PRIORITY_DEFAULT
 ASDISPLAYNODE_EXTERN_C_END
 
-#ifndef ASDISPLAYNODE_EVENTLOG_CAPACITY
-#define ASDISPLAYNODE_EVENTLOG_CAPACITY 20
-#endif
-
-#ifndef ASDISPLAYNODE_EVENTLOG_ENABLE
-#define ASDISPLAYNODE_EVENTLOG_ENABLE DEBUG
+#if ASEVENTLOG_ENABLE
+#define ASDisplayNodeLogEvent(node, ...) [node.eventLog logEventWithBacktrace:[NSThread callStackSymbols] format:__VA_ARGS__]
+#else
+#define ASDisplayNodeLogEvent(node, ...)
 #endif
 
-#if ASDISPLAYNODE_EVENTLOG_ENABLE
-#define ASDisplayNodeLogEvent(node, ...) [node _logEventWithBacktrace:[NSThread callStackSymbols] format:__VA_ARGS__]
+#if ASEVENTLOG_ENABLE
+#define ASDisplayNodeGetEventLog(node) node.eventLog
 #else
-#define ASDisplayNodeLogEvent(node, ...)
+#define ASDisplayNodeGetEventLog(node) nil
 #endif
 
 /**
@@ -94,6 +92,13 @@ typedef struct {
  */
 @property (nonatomic, assign, readonly) ASDisplayNodePerformanceMeasurements performanceMeasurements;
 
+#if ASEVENTLOG_ENABLE
+/*
+ * @abstract The primitive event tracing object. You shouldn't directly use it to log event. Use the ASDisplayNodeLogEvent macro instead.
+ */
+@property (nonatomic, strong, readonly) ASEventLog *eventLog;
+#endif
+
 /**
  * @abstract Currently used by ASNetworkImageNode and ASMultiplexImageNode to allow their placeholders to stay if they are loading an image from the network.
  * Otherwise, a display pass is scheduled and completes, but does not actually draw anything - and ASDisplayNode considers the element finished.
@@ -118,20 +123,6 @@ typedef struct {
  */
 + (void)setRangeModeForMemoryWarnings:(ASLayoutRangeMode)rangeMode;
 
-#if ASDISPLAYNODE_EVENTLOG_ENABLE
-
-/**
- * The primitive event tracing method. You shouldn't call this. Use the ASDisplayNodeLogEvent macro instead.
- */
-- (void)_logEventWithBacktrace:(NSArray<NSString *> *)backtrace format:(NSString *)format, ... NS_FORMAT_FUNCTION(2, 3);
-
-/**
- * @abstract The most recent trace events for this node. Max count is ASDISPLAYNODE_EVENTLOG_CAPACITY.
- */
-@property (readonly, copy) NSArray *eventLog;
-
-#endif
-
 @end
 
 NS_ASSUME_NONNULL_END

AsyncDisplayKit/ASDisplayNode.mm

@@ -300,7 +300,11 @@ - (void)_staticInitialize
 - (void)_initializeInstance
 {
   [self _staticInitialize];
-  _eventLogHead = -1;
+
+#if ASEVENTLOG_ENABLE
+  _eventLog = [[ASEventLog alloc] init];
+#endif
+  
   _contentsScaleForDisplay = ASScreenScale();
 
   _environmentState = ASEnvironmentStateMakeDefault();
@@ -575,51 +579,6 @@ - (void)_loadViewOrLayerIsLayerBacked:(BOOL)isLayerBacked
   }
 }
 
-#if ASDISPLAYNODE_EVENTLOG_ENABLE
-- (void)_logEventWithBacktrace:(NSArray<NSString *> *)backtrace format:(NSString *)format, ...
-{
-  va_list args;
-  va_start(args, format);
-  ASTraceEvent *event = [[ASTraceEvent alloc] initWithObject:self
-                                                   backtrace:backtrace
-                                                      format:format
-                                                   arguments:args];
-  va_end(args);
-
-  ASDN::MutexLocker l(__instanceLock__);
-  // Create the array if needed.
-  if (_eventLog == nil) {
-    _eventLog = [NSMutableArray arrayWithCapacity:ASDISPLAYNODE_EVENTLOG_CAPACITY];
-  }
-
-	// Increment the head index.
-  _eventLogHead = (_eventLogHead + 1) % ASDISPLAYNODE_EVENTLOG_CAPACITY;
-  if (_eventLogHead < _eventLog.count) {
-    [_eventLog replaceObjectAtIndex:_eventLogHead withObject:event];
-  } else {
-    [_eventLog insertObject:event atIndex:_eventLogHead];
-  }
-}
-
-- (NSArray<ASTraceEvent *> *)eventLog
-{
-  ASDN::MutexLocker l(__instanceLock__);
-  NSUInteger tail = (_eventLogHead + 1);
-  NSUInteger count = _eventLog.count;
-
-  NSMutableArray<ASTraceEvent *> *result = [NSMutableArray array];
-
-  // Start from `tail` and go through array, wrapping around when we exceed end index.
-  for (NSUInteger actualIndex = 0; actualIndex < ASDISPLAYNODE_EVENTLOG_CAPACITY; actualIndex++) {
-    NSInteger ringIndex = (tail + actualIndex) % ASDISPLAYNODE_EVENTLOG_CAPACITY;
-    if (ringIndex < count) {
-      [result addObject:_eventLog[ringIndex]];
-    }
-  }
-  return result;
-}
-#endif
-
 - (UIView *)view
 {
   ASDisplayNodeAssert(!_flags.layerBacked, @"Call to -view undefined on layer-backed nodes");
@@ -3344,6 +3303,13 @@ - (void)setInHierarchy:(BOOL)inHierarchy
 
 #pragma mark Debugging (Private)
 
+#if ASEVENTLOG_ENABLE
+- (ASEventLog *)eventLog
+{
+  return _eventLog;
+}
+#endif
+
 - (NSMutableArray<NSDictionary *> *)propertiesForDescription
 {
   NSMutableArray<NSDictionary *> *result = [NSMutableArray array];

AsyncDisplayKit/ASTableNode.mm

@@ -13,6 +13,7 @@
 #import "ASTableNode.h"
 #import "ASTableViewInternal.h"
 #import "ASEnvironmentInternal.h"
+#import "ASDisplayNodeInternal.h"
 #import "ASDisplayNode+Subclasses.h"
 #import "ASInternalHelpers.h"
 #import "ASCellNode+Internal.h"
@@ -79,7 +80,7 @@ - (instancetype)_initWithTableView:(ASTableView *)tableView
 - (instancetype)_initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass
 {
   ASDisplayNodeViewBlock tableViewBlock = ^UIView *{
-    return [[ASTableView alloc] _initWithFrame:frame style:style dataControllerClass:dataControllerClass];
+    return [[ASTableView alloc] _initWithFrame:frame style:style dataControllerClass:dataControllerClass eventLog:ASDisplayNodeGetEventLog(self)];
   };
 
   if (self = [super initWithViewBlock:tableViewBlock]) {
@@ -574,4 +575,14 @@ - (void)waitUntilAllUpdatesAreCommitted
   [self.view waitUntilAllUpdatesAreCommitted];
 }
 
+#pragma mark - Debugging (Private)
+
+- (NSMutableArray<NSDictionary *> *)propertiesForDebugDescription
+{
+  NSMutableArray<NSDictionary *> *result = [super propertiesForDebugDescription];
+  [result addObject:@{ @"dataSource" : ASObjectDescriptionMakeTiny(self.dataSource) }];
+  [result addObject:@{ @"delegate" : ASObjectDescriptionMakeTiny(self.delegate) }];
+  return result;
+}
+
 @end

AsyncDisplayKit/ASTableView.mm

@@ -212,7 +212,7 @@ + (Class)dataControllerClass
 #pragma mark -
 #pragma mark Lifecycle
 
-- (void)configureWithDataControllerClass:(Class)dataControllerClass
+- (void)configureWithDataControllerClass:(Class)dataControllerClass eventLog:(ASEventLog *)eventLog
 {
   _layoutController = [[ASFlowLayoutController alloc] initWithScrollOption:ASFlowLayoutDirectionVertical];
 
@@ -221,7 +221,7 @@ - (void)configureWithDataControllerClass:(Class)dataControllerClass
   _rangeController.dataSource = self;
   _rangeController.delegate = self;
 
-  _dataController = [[dataControllerClass alloc] initWithDataSource:self];
+  _dataController = [[dataControllerClass alloc] initWithDataSource:self eventLog:eventLog];
   _dataController.delegate = _rangeController;
   _dataController.environmentDelegate = self;
 
@@ -248,10 +248,10 @@ - (void)configureWithDataControllerClass:(Class)dataControllerClass
 
 - (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style
 {
-  return [self _initWithFrame:frame style:style dataControllerClass:nil];
+  return [self _initWithFrame:frame style:style dataControllerClass:nil eventLog:nil];
 }
 
-- (instancetype)_initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass
+- (instancetype)_initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass eventLog:(ASEventLog *)eventLog
 {
   if (!(self = [super initWithFrame:frame style:style])) {
     return nil;
@@ -261,7 +261,7 @@ - (instancetype)_initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataC
     dataControllerClass = [[self class] dataControllerClass];
   }
 
-  [self configureWithDataControllerClass:dataControllerClass];
+  [self configureWithDataControllerClass:dataControllerClass eventLog:eventLog];
 
   if (!AS_AT_LEAST_IOS9) {
     _retainedLayer = self.layer;

AsyncDisplayKit/ASTableViewInternal.h

@@ -31,8 +31,10 @@
  * @param style A constant that specifies the style of the table view. See UITableViewStyle for descriptions of valid constants.
  *
  * @param dataControllerClass A controller class injected to and used to create a data controller for the table view.
+ *
+ * @param eventLog An event log passed through to the data controller.
  */
-- (instancetype)_initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass;
+- (instancetype)_initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass eventLog:(ASEventLog *)eventLog;
 
 /// Set YES and we'll log every time we call [super insertRows…] etc
 @property (nonatomic) BOOL test_enableSuperUpdateCallLogging;

AsyncDisplayKit/Details/ASChangeSetDataController.mm

@@ -47,7 +47,7 @@ - (void)endUpdatesAnimated:(BOOL)animated completion:(void (^)(BOOL))completion
 
   [_changeSet addCompletionHandler:completion];
   if (_changeSetBatchUpdateCounter == 0) {
-    void (^batchCompletion)(BOOL finished) = _changeSet.completionHandler;
+    void (^batchCompletion)(BOOL) = _changeSet.completionHandler;
 
     /**
      * If the initial reloadData has not been called, just bail because we don't have
@@ -66,6 +66,8 @@ - (void)endUpdatesAnimated:(BOOL)animated completion:(void (^)(BOOL))completion
     [self invalidateDataSourceItemCounts];
     [_changeSet markCompletedWithNewItemCounts:[self itemCountsFromDataSource]];
 
+    ASDataControllerLogEvent(self, @"triggeredUpdate: %@", _changeSet);
+    
     [super beginUpdates];
 
     for (_ASHierarchyItemChange *change in [_changeSet itemChangesOfType:_ASHierarchyChangeTypeDelete]) {
@@ -84,6 +86,16 @@ - (void)endUpdatesAnimated:(BOOL)animated completion:(void (^)(BOOL))completion
       [super insertRowsAtIndexPaths:change.indexPaths withAnimationOptions:change.animationOptions];
     }
 
+#if ASEVENTLOG_ENABLE
+    NSString *changeSetDescription = ASObjectDescriptionMakeTiny(_changeSet);
+    batchCompletion = ^(BOOL finished) {
+      if (batchCompletion != nil) {
+        batchCompletion(finished);
+      }
+      ASDataControllerLogEvent(self, @"finishedUpdate: %@", changeSetDescription);
+    };
+#endif
+    
     [super endUpdatesAnimated:animated completion:batchCompletion];
 
     _changeSet = nil;

AsyncDisplayKit/Details/ASCollectionDataController.h

@@ -43,7 +43,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface ASCollectionDataController : ASChangeSetDataController
 
-- (instancetype)initWithDataSource:(id<ASCollectionDataControllerSource>)dataSource NS_DESIGNATED_INITIALIZER;
+- (instancetype)initWithDataSource:(id<ASCollectionDataControllerSource>)dataSource eventLog:(nullable ASEventLog *)eventLog NS_DESIGNATED_INITIALIZER;
 
 - (ASCellNode *)supplementaryNodeOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath;