[ASDataController] Clean up (TextureGroup#443)

* Clean up ASDataController - Parameters passed to ASDataControllerCompletionBlock are no longer used. Remove them. - The value returned by _allocateNodesFromElements:andLayout:completion is not used. Remove it. - Elements are not allocated and measured in batches anymore. Remove the code that does batch allocation. - Remove RETURN_IF_NO_DATASOURCE. It's used only once and is not worth it. * Remove +parallelProcessorCount * Update CHANGELOG
AtomTickets · Apr 25, 2018 · ccc8287 · ccc8287
1 parent 250d7b2
commit ccc8287
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Showing 2 changed files with 34 additions and 64 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -12,6 +12,7 @@
 - Fix a crash where scrolling a table view after entering editing mode could lead to bad internal states in the table. [Huy Nguyen](https://github.com/nguyenhuy) [#416](https://github.com/TextureGroup/Texture/pull/416/)
 - Fix a crash in collection view that occurs if batch updates are performed while scrolling [Huy Nguyen](https://github.com/nguyenhuy) [#378](https://github.com/TextureGroup/Texture/issues/378)
 - Some improvements in ASCollectionView [Huy Nguyen](https://github.com/nguyenhuy) [#407](https://github.com/TextureGroup/Texture/pull/407)
+- Small refactors in ASDataController [Huy Nguyen](https://github.com/TextureGroup/Texture/pull/443) [#443](https://github.com/TextureGroup/Texture/pull/443)
 
 ##2.3.4
 - [Yoga] Rewrite YOGA_TREE_CONTIGUOUS mode with improved behavior and cleaner integration [Scott Goodson](https://github.com/appleguy)

diff --git a/Source/Details/ASDataController.mm b/Source/Details/ASDataController.mm
@@ -44,10 +44,8 @@
 //#define LOG(...) NSLog(__VA_ARGS__)
 #define LOG(...)
 
-#define RETURN_IF_NO_DATASOURCE(val) if (_dataSource == nil) { return val; }
 #define ASSERT_ON_EDITING_QUEUE ASDisplayNodeAssertNotNil(dispatch_get_specific(&kASDataControllerEditingQueueKey), @"%@ must be called on the editing transaction queue.", NSStringFromSelector(_cmd))
 
-const static NSUInteger kASDataControllerSizingCountPerProcessor = 5;
 const static char * kASDataControllerEditingQueueKey = "kASDataControllerEditingQueueKey";
 const static char * kASDataControllerEditingQueueContext = "kASDataControllerEditingQueueContext";
 
@@ -123,18 +121,6 @@ - (instancetype)initWithDataSource:(id<ASDataControllerSource>)dataSource node:(
   return self;
 }
 
-+ (NSUInteger)parallelProcessorCount
-{
-  static NSUInteger parallelProcessorCount;
-
-  static dispatch_once_t onceToken;
-  dispatch_once(&onceToken, ^{
-    parallelProcessorCount = [[NSProcessInfo processInfo] activeProcessorCount];
-  });
-
-  return parallelProcessorCount;
-}
-
 - (id<ASDataControllerLayoutDelegate>)layoutDelegate
 {
   ASDisplayNodeAssertMainThread();
@@ -151,34 +137,47 @@ - (void)setLayoutDelegate:(id<ASDataControllerLayoutDelegate>)layoutDelegate
 
 #pragma mark - Cell Layout
 
-- (void)batchAllocateNodesFromElements:(NSArray<ASCollectionElement *> *)elements batchSize:(NSInteger)batchSize batchCompletion:(ASDataControllerCompletionBlock)batchCompletionHandler
+- (void)_allocateNodesFromElements:(NSArray<ASCollectionElement *> *)elements completion:(ASDataControllerCompletionBlock)completionHandler
 {
   ASSERT_ON_EDITING_QUEUE;
-
-  if (elements.count == 0 || _dataSource == nil) {
-    batchCompletionHandler();
+
+  NSUInteger nodeCount = elements.count;
+  __weak id<ASDataControllerSource> weakDataSource = _dataSource;
+  if (nodeCount == 0 || weakDataSource == nil) {
+    completionHandler();
     return;
   }
 
   ASSignpostStart(ASSignpostDataControllerBatch);
 
-  if (batchSize == 0) {
-    batchSize = [[ASDataController class] parallelProcessorCount] * kASDataControllerSizingCountPerProcessor;
-  }
-  NSUInteger count = elements.count;
-
-  // Processing in batches
-  for (NSUInteger i = 0; i < count; i += batchSize) {
-    NSRange batchedRange = NSMakeRange(i, MIN(count - i, batchSize));
-    NSArray<ASCollectionElement *> *batchedElements = [elements subarrayWithRange:batchedRange];
-    {
-      as_activity_create_for_scope("Data controller  batch");
-      [self _allocateNodesFromElements:batchedElements];
-    }
-    batchCompletionHandler();
+  {
+    as_activity_create_for_scope("Data controller batch");
+
+    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
+    ASDispatchApply(nodeCount, queue, 0, ^(size_t i) {
+      __strong id<ASDataControllerSource> strongDataSource = weakDataSource;
+      if (strongDataSource == nil) {
+        return;
+      }
+
+      // Allocate the node.
+      ASCollectionElement *context = elements[i];
+      ASCellNode *node = context.node;
+      if (node == nil) {
+        ASDisplayNodeAssertNotNil(node, @"Node block created nil node; %@, %@", self, strongDataSource);
+        node = [[ASCellNode alloc] init]; // Fallback to avoid crash for production apps.
+      }
+
+      // Layout the node if the size range is valid.
+      ASSizeRange sizeRange = context.constrainedSize;
+      if (ASSizeRangeHasSignificantArea(sizeRange)) {
+        [self _layoutNode:node withConstrainedSize:sizeRange];
+      }
+    });
   }
 
-  ASSignpostEndCustom(ASSignpostDataControllerBatch, self, 0, (_dataSource != nil ? ASSignpostColorDefault : ASSignpostColorRed));
+  completionHandler();
+  ASSignpostEndCustom(ASSignpostDataControllerBatch, self, 0, (weakDataSource != nil ? ASSignpostColorDefault : ASSignpostColorRed));
 }
 
 /**
@@ -193,36 +192,6 @@ - (void)_layoutNode:(ASCellNode *)node withConstrainedSize:(ASSizeRange)constrai
   node.frame = frame;
 }
 
-// TODO Is returned array still needed? Can it be removed?
-- (void)_allocateNodesFromElements:(NSArray<ASCollectionElement *> *)elements
-{
-  ASSERT_ON_EDITING_QUEUE;
-
-  NSUInteger nodeCount = elements.count;
-  if (!nodeCount || _dataSource == nil) {
-    return;
-  }
-
-  dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
-  ASDispatchApply(nodeCount, queue, 0, ^(size_t i) {
-    RETURN_IF_NO_DATASOURCE();
-
-    // Allocate the node.
-    ASCollectionElement *context = elements[i];
-    ASCellNode *node = context.node;
-    if (node == nil) {
-      ASDisplayNodeAssertNotNil(node, @"Node block created nil node; %@, %@", self, self.dataSource);
-      node = [[ASCellNode alloc] init]; // Fallback to avoid crash for production apps.
-    }
-
-    // Layout the node if the size range is valid.
-    ASSizeRange sizeRange = context.constrainedSize;
-    if (ASSizeRangeHasSignificantArea(sizeRange)) {
-      [self _layoutNode:node withConstrainedSize:sizeRange];
-    }
-  });
-}
-
 #pragma mark - Data Source Access (Calling _dataSource)
 
 - (NSArray<NSIndexPath *> *)_allIndexPathsForItemsOfKind:(NSString *)kind inSections:(NSIndexSet *)sections
@@ -592,7 +561,7 @@ - (void)updateWithChangeSet:(_ASHierarchyChangeSet *)changeSet
       NSArray<ASCollectionElement *> *elementsToProcess = ASArrayByFlatMapping(newMap,
                                                                                ASCollectionElement *element,
                                                                                (element.nodeIfAllocated.calculatedLayout == nil ? element : nil));
-      [self batchAllocateNodesFromElements:elementsToProcess batchSize:elementsToProcess.count batchCompletion:completion];
+      [self _allocateNodesFromElements:elementsToProcess completion:completion];
     }
   });