Shrink ASDisplayNode from 1072 to 968 bytes, reduction of 10.74% (Tex…

…tureGroup#1484)

* Shrink ASDisplayNode from 1088 to 976 bytes, reduction of 11.48%

These objects accumulate in the heap, so reducing their size will allow more to accumulate before memory warnings.

Group the `BOOL`s into a struct. Shrink the various stored `enum`s to fit the size of their contents. Move the ivars around so that the smaller `enum` are near eachother and the bitfield struct.

* Forgot to bit-field-ify placeholderEnable; new small size is 968, old size is 1072 (measured consistentlyl on iPhoneSE simulator). 10.74% reduction.

Source/ASDisplayNode+Beta.h

@@ -25,7 +25,7 @@ AS_EXTERN void ASPerformBlockOnBackgroundThread(void (^block)(void)); // DISPATC
 /**
  * Bitmask to indicate what performance measurements the cell should record.
  */
-typedef NS_OPTIONS(NSUInteger, ASDisplayNodePerformanceMeasurementOptions) {
+typedef NS_OPTIONS(unsigned char, ASDisplayNodePerformanceMeasurementOptions) {
   ASDisplayNodePerformanceMeasurementOptionLayoutSpec = 1 << 0,
   ASDisplayNodePerformanceMeasurementOptionLayoutComputation = 1 << 1
 };

Source/ASDisplayNode+InterfaceState.h

@@ -16,7 +16,7 @@
  * The defualt state, ASInterfaceStateNone, means that the element is not predicted to be onscreen soon and
  * preloading should not be performed. Swift: use [] for the default behavior.
  */
-typedef NS_OPTIONS(NSUInteger, ASInterfaceState)
+typedef NS_OPTIONS(unsigned char, ASInterfaceState)
 {
     /** The element is not predicted to be onscreen soon and preloading should not be performed */
     ASInterfaceStateNone          = 0,

Source/ASDisplayNode+Layout.mm

@@ -547,13 +547,13 @@ @implementation ASDisplayNode (ASAutomaticSubnodeManagement)
 - (BOOL)automaticallyManagesSubnodes
 {
   MutexLocker l(__instanceLock__);
-  return _automaticallyManagesSubnodes;
+  return _flags.automaticallyManagesSubnodes;
 }
 
 - (void)setAutomaticallyManagesSubnodes:(BOOL)automaticallyManagesSubnodes
 {
   MutexLocker l(__instanceLock__);
-  _automaticallyManagesSubnodes = automaticallyManagesSubnodes;
+  _flags.automaticallyManagesSubnodes = automaticallyManagesSubnodes;
 }
 
 @end
@@ -1027,7 +1027,7 @@ - (void)_pendingLayoutTransitionDidComplete
   // We generate placeholders at -layoutThatFits: time so that a node is guaranteed to have a placeholder ready to go.
   // This is also because measurement is usually asynchronous, but placeholders need to be set up synchronously.
   // First measurement is guaranteed to be before the node is onscreen, so we can create the image async. but still have it appear sync.
-  if (_placeholderEnabled && !_placeholderImage && [self _locked_displaysAsynchronously]) {
+  if (_flags.placeholderEnabled && !_placeholderImage && [self _locked_displaysAsynchronously]) {
 
     // Zero-sized nodes do not require a placeholder.
     CGSize layoutSize = _calculatedDisplayNodeLayout.layout.size;

Source/ASDisplayNode+Yoga.mm

@@ -167,11 +167,11 @@ - (ASLayout *)yogaCalculatedLayout
 }
 
 - (BOOL)willApplyNextYogaCalculatedLayout {
-  return _willApplyNextYogaCalculatedLayout;
+  return _flags.willApplyNextYogaCalculatedLayout;
 }
 
 - (void)setWillApplyNextYogaCalculatedLayout:(BOOL)willApplyNextYogaCalculatedLayout {
-  _willApplyNextYogaCalculatedLayout = willApplyNextYogaCalculatedLayout;
+  _flags.willApplyNextYogaCalculatedLayout = willApplyNextYogaCalculatedLayout;
 }
 
 - (void)setYogaLayoutInProgress:(BOOL)yogaLayoutInProgress

Source/ASDisplayNode.h

@@ -70,7 +70,7 @@ typedef ASLayoutSpec * _Nonnull(^ASLayoutSpecBlock)(__kindof ASDisplayNode *node
  */
 typedef void (^ASDisplayNodeNonFatalErrorBlock)(NSError *error);
 
-typedef NS_ENUM(NSInteger, ASCornerRoundingType) {
+typedef NS_ENUM(unsigned char, ASCornerRoundingType) {
   ASCornerRoundingTypeDefaultSlowCALayer,
   ASCornerRoundingTypePrecomposited,
   ASCornerRoundingTypeClipping

Source/ASDisplayNode.mm

@@ -338,11 +338,11 @@ - (void)_initializeInstance
   _flags.canCallSetNeedsDisplayOfLayer = YES;
 
   _fallbackSafeAreaInsets = UIEdgeInsetsZero;
-  _fallbackInsetsLayoutMarginsFromSafeArea = YES;
-  _isViewControllerRoot = NO;
+  _flags.fallbackInsetsLayoutMarginsFromSafeArea = YES;
+  _flags.isViewControllerRoot = NO;
 
-  _automaticallyRelayoutOnSafeAreaChanges = NO;
-  _automaticallyRelayoutOnLayoutMarginsChanges = NO;
+  _flags.automaticallyRelayoutOnSafeAreaChanges = NO;
+  _flags.automaticallyRelayoutOnLayoutMarginsChanges = NO;
 
   [self baseDidInit];
 }
@@ -862,37 +862,37 @@ - (void)_fallbackUpdateSafeAreaOnChildren
 - (BOOL)isViewControllerRoot
 {
   MutexLocker l(__instanceLock__);
-  return _isViewControllerRoot;
+  return _flags.isViewControllerRoot;
 }
 
 - (void)setViewControllerRoot:(BOOL)flag
 {
   MutexLocker l(__instanceLock__);
-  _isViewControllerRoot = flag;
+  _flags.isViewControllerRoot = flag;
 }
 
 - (BOOL)automaticallyRelayoutOnSafeAreaChanges
 {
   MutexLocker l(__instanceLock__);
-  return _automaticallyRelayoutOnSafeAreaChanges;
+  return _flags.automaticallyRelayoutOnSafeAreaChanges;
 }
 
 - (void)setAutomaticallyRelayoutOnSafeAreaChanges:(BOOL)flag
 {
   MutexLocker l(__instanceLock__);
-  _automaticallyRelayoutOnSafeAreaChanges = flag;
+  _flags.automaticallyRelayoutOnSafeAreaChanges = flag;
 }
 
 - (BOOL)automaticallyRelayoutOnLayoutMarginsChanges
 {
   MutexLocker l(__instanceLock__);
-  return _automaticallyRelayoutOnLayoutMarginsChanges;
+  return _flags.automaticallyRelayoutOnLayoutMarginsChanges;
 }
 
 - (void)setAutomaticallyRelayoutOnLayoutMarginsChanges:(BOOL)flag
 {
   MutexLocker l(__instanceLock__);
-  _automaticallyRelayoutOnLayoutMarginsChanges = flag;
+  _flags.automaticallyRelayoutOnLayoutMarginsChanges = flag;
 }
 
 - (void)__setNodeController:(ASNodeController *)controller
@@ -2592,7 +2592,7 @@ - (void)_locked_layoutPlaceholderIfNecessary
 - (BOOL)_locked_shouldHavePlaceholderLayer
 {
   DISABLED_ASAssertLocked(__instanceLock__);
-  return (_placeholderEnabled && [self _implementsDisplay]);
+  return (_flags.placeholderEnabled && [self _implementsDisplay]);
 }
 
 - (void)_locked_setupPlaceholderLayerIfNeeded
@@ -2637,13 +2637,13 @@ - (BOOL)placeholderShouldPersist
 - (BOOL)placeholderEnabled
 {
   MutexLocker l(__instanceLock__);
-  return _placeholderEnabled;
+  return _flags.placeholderEnabled;
 }
 
 - (void)setPlaceholderEnabled:(BOOL)placeholderEnabled
 {
   MutexLocker l(__instanceLock__);
-  _placeholderEnabled = placeholderEnabled;
+  _flags.placeholderEnabled = placeholderEnabled;
 }
 
 - (NSTimeInterval)placeholderFadeDuration
@@ -3143,7 +3143,7 @@ - (BOOL)shouldScheduleDisplayWithNewInterfaceState:(ASInterfaceState)newInterfac
 - (void)addInterfaceStateDelegate:(id <ASInterfaceStateDelegate>)interfaceStateDelegate
 {
   MutexLocker l(__instanceLock__);
-  _hasHadInterfaceStateDelegates = YES;
+  _flags.hasHadInterfaceStateDelegates = YES;
   for (int i = 0; i < AS_MAX_INTERFACE_STATE_DELEGATES; i++) {
     if (_interfaceStateDelegates[i] == nil) {
       _interfaceStateDelegates[i] = interfaceStateDelegate;
@@ -3325,7 +3325,7 @@ - (void)enumerateInterfaceStateDelegates:(void (NS_NOESCAPE ^)(id<ASInterfaceSta
   {
     ASLockScopeSelf();
     // Fast path for non-delegating nodes.
-    if (!_hasHadInterfaceStateDelegates) {
+    if (!_flags.hasHadInterfaceStateDelegates) {
       return;
     }
 
@@ -3537,13 +3537,13 @@ - (ASDisplayNodePerformanceMeasurements)performanceMeasurements
 - (void)setIsAccessibilityContainer:(BOOL)isAccessibilityContainer
 {
   MutexLocker l(__instanceLock__);
-  _isAccessibilityContainer = isAccessibilityContainer;
+  _flags.isAccessibilityContainer = isAccessibilityContainer;
 }
 
 - (BOOL)isAccessibilityContainer
 {
   MutexLocker l(__instanceLock__);
-  return _isAccessibilityContainer;
+  return _flags.isAccessibilityContainer;
 }
 
 - (NSString *)defaultAccessibilityLabel

Source/ASImageNode.mm

@@ -284,7 +284,7 @@ - (void)setPlaceholderColor:(UIColor *)placeholderColor
 {
   ASLockScopeSelf();
   if (ASCompareAssignCopy(_placeholderColor, placeholderColor)) {
-    _placeholderEnabled = (placeholderColor != nil);
+    _flags.placeholderEnabled = (placeholderColor != nil);
   }
 }
 

Source/Private/ASDisplayNode+FrameworkPrivate.h

@@ -31,7 +31,7 @@ NS_ASSUME_NONNULL_BEGIN
  cancelled below the point they are enabled.  They continue to the leaves of the hierarchy.
  */
 
-typedef NS_OPTIONS(NSUInteger, ASHierarchyState)
+typedef NS_OPTIONS(unsigned char, ASHierarchyState)
 {
   /** The node may or may not have a supernode, but no supernode has a special hierarchy-influencing option enabled. */
   ASHierarchyStateNormal                  = 0,
@@ -115,11 +115,6 @@ __unused static NSString * _Nonnull NSStringFromASHierarchyStateChange(ASHierarc
 #undef HIERARCHY_STATE_DELTA
 
 @interface ASDisplayNode () <ASDescriptionProvider, ASDebugDescriptionProvider>
-{
-@protected
-  ASInterfaceState _interfaceState;
-  ASHierarchyState _hierarchyState;
-}
 
 // The view class to use when creating a new display node instance. Defaults to _ASDisplayView.
 + (Class)viewClass;

Source/Private/ASDisplayNode+UIViewBridge.mm

@@ -943,7 +943,7 @@ - (void)setInsetsLayoutMarginsFromSafeArea:(BOOL)insetsLayoutMarginsFromSafeArea
   {
     _bridge_prologue_write;
 
-    _fallbackInsetsLayoutMarginsFromSafeArea = insetsLayoutMarginsFromSafeArea;
+    _flags.fallbackInsetsLayoutMarginsFromSafeArea = insetsLayoutMarginsFromSafeArea;
 
     if (AS_AVAILABLE_IOS(11.0)) {
       if (!_flags.layerBacked) {
@@ -1027,7 +1027,7 @@ - (BOOL)_locked_insetsLayoutMarginsFromSafeArea
       return _getFromViewOnly(insetsLayoutMarginsFromSafeArea);
     }
   }
-  return _fallbackInsetsLayoutMarginsFromSafeArea;
+  return _flags.fallbackInsetsLayoutMarginsFromSafeArea;
 }
 
 @end
@@ -1056,13 +1056,13 @@ @implementation ASDisplayNode (UIViewBridgeAccessibility)
 - (BOOL)isAccessibilityElement
 {
   _bridge_prologue_read;
-  return _getAccessibilityFromViewOrProperty(_isAccessibilityElement, isAccessibilityElement);
+  return _getAccessibilityFromViewOrProperty(_flags.isAccessibilityElement, isAccessibilityElement);
 }
 
 - (void)setIsAccessibilityElement:(BOOL)isAccessibilityElement
 {
   _bridge_prologue_write;
-  _setAccessibilityToViewAndProperty(_isAccessibilityElement, isAccessibilityElement, isAccessibilityElement, isAccessibilityElement);
+  _setAccessibilityToViewAndProperty(_flags.isAccessibilityElement, isAccessibilityElement, isAccessibilityElement, isAccessibilityElement);
 }
 
 - (NSString *)accessibilityLabel
@@ -1192,37 +1192,37 @@ - (void)setAccessibilityLanguage:(NSString *)accessibilityLanguage
 - (BOOL)accessibilityElementsHidden
 {
   _bridge_prologue_read;
-  return _getAccessibilityFromViewOrProperty(_accessibilityElementsHidden, accessibilityElementsHidden);
+  return _getAccessibilityFromViewOrProperty(_flags.accessibilityElementsHidden, accessibilityElementsHidden);
 }
 
 - (void)setAccessibilityElementsHidden:(BOOL)accessibilityElementsHidden
 {
   _bridge_prologue_write;
-  _setAccessibilityToViewAndProperty(_accessibilityElementsHidden, accessibilityElementsHidden, accessibilityElementsHidden, accessibilityElementsHidden);
+  _setAccessibilityToViewAndProperty(_flags.accessibilityElementsHidden, accessibilityElementsHidden, accessibilityElementsHidden, accessibilityElementsHidden);
 }
 
 - (BOOL)accessibilityViewIsModal
 {
   _bridge_prologue_read;
-  return _getAccessibilityFromViewOrProperty(_accessibilityViewIsModal, accessibilityViewIsModal);
+  return _getAccessibilityFromViewOrProperty(_flags.accessibilityViewIsModal, accessibilityViewIsModal);
 }
 
 - (void)setAccessibilityViewIsModal:(BOOL)accessibilityViewIsModal
 {
   _bridge_prologue_write;
-  _setAccessibilityToViewAndProperty(_accessibilityViewIsModal, accessibilityViewIsModal, accessibilityViewIsModal, accessibilityViewIsModal);
+  _setAccessibilityToViewAndProperty(_flags.accessibilityViewIsModal, accessibilityViewIsModal, accessibilityViewIsModal, accessibilityViewIsModal);
 }
 
 - (BOOL)shouldGroupAccessibilityChildren
 {
   _bridge_prologue_read;
-  return _getAccessibilityFromViewOrProperty(_shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren);
+  return _getAccessibilityFromViewOrProperty(_flags.shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren);
 }
 
 - (void)setShouldGroupAccessibilityChildren:(BOOL)shouldGroupAccessibilityChildren
 {
   _bridge_prologue_write;
-  _setAccessibilityToViewAndProperty(_shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren);
+  _setAccessibilityToViewAndProperty(_flags.shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren, shouldGroupAccessibilityChildren);
 }
 
 - (NSString *)accessibilityIdentifier