From e799ed9ea478e5223ae3206162e400fbb648ff84 Mon Sep 17 00:00:00 2001
From: Li Tan <lit@fb.com>
Date: Thu, 18 Dec 2014 13:58:44 -0800
Subject: [PATCH] fix

---
 AsyncDisplayKit/Details/ASDataController.mm   | 38 ++++++++++++++-----
 .../Details/ASFlowLayoutController.mm         |  3 +-
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/AsyncDisplayKit/Details/ASDataController.mm b/AsyncDisplayKit/Details/ASDataController.mm
index 5f6e2ee0ac..47489bce35 100644
--- a/AsyncDisplayKit/Details/ASDataController.mm
+++ b/AsyncDisplayKit/Details/ASDataController.mm
@@ -205,22 +205,40 @@ static void *kASDataUpdatingQueueContext = &kASDataUpdatingQueueContext;
 #pragma mark - Data Update
 
 - (void)insertSections:(NSIndexSet *)indexSet {
-  NSMutableArray *sectionArray = [[NSMutableArray alloc] initWithCapacity:indexSet.count];
-  for (NSUInteger i = 0; i < indexSet.count; i++) {
-    NSUInteger rowNum = [_dataSource dataController:self rowsInSection:i];
-    NSMutableArray *rows = [[NSMutableArray alloc] initWithCapacity:rowNum];
+  __block int nodeTotalCnt = 0;
+  NSMutableArray *nodeCounts = [NSMutableArray arrayWithCapacity:indexSet.count];
+  [indexSet enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL *stop) {
+    NSUInteger cnt = [_dataSource dataController:self rowsInSection:idx];
+    [nodeCounts addObject:@(cnt)];
+    nodeTotalCnt += cnt;
+  }];
 
-    for (NSUInteger j = 0; j < rowNum; j++) {
-      ASCellNode *node = [_dataSource dataController:self nodeAtIndexPath:[NSIndexPath indexPathForItem:j inSection:i]];
-      [rows addObject:node];
+  NSMutableArray *nodes = [NSMutableArray arrayWithCapacity:nodeTotalCnt];
+  NSMutableArray *indexPaths = [NSMutableArray arrayWithCapacity:nodeTotalCnt];
+
+  __block NSUInteger idx = 0;
+  [indexSet enumerateIndexesUsingBlock:^(NSUInteger sectionIdx, BOOL *stop) {
+    NSUInteger cnt = [nodeCounts[idx++] unsignedIntegerValue];
+
+    for (int i = 0; i < cnt; i++) {
+      NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:sectionIdx];
+      [indexPaths addObject:indexPath];
+
+      ASCellNode *node = [_dataSource dataController:self nodeAtIndexPath:indexPath];
+      [nodes addObject:node];
     }
-    [sectionArray addObject:rows];
-  }
+  }];
 
   dispatch_async([[self class] sizingQueue], ^{
-    [self asyncUpdateDataWithBlock:^{
+    [self syncUpdateDataWithBlock:^{
+      NSMutableArray *sectionArray = [NSMutableArray arrayWithCapacity:indexSet.count];
+      for (NSUInteger i = 0; i < indexSet.count; i++) {
+        [sectionArray addObject:[NSMutableArray array]];
+      }
       INSERT_SECTIONS(_nodes , indexSet, sectionArray);
     }];
+
+    [self _insertNodes:nodes atIndexPaths:indexPaths];
   });
 }
 
diff --git a/AsyncDisplayKit/Details/ASFlowLayoutController.mm b/AsyncDisplayKit/Details/ASFlowLayoutController.mm
index 91f35b91d6..27a932d68a 100644
--- a/AsyncDisplayKit/Details/ASFlowLayoutController.mm
+++ b/AsyncDisplayKit/Details/ASFlowLayoutController.mm
@@ -57,7 +57,8 @@ static const CGFloat kASFlowLayoutControllerRefreshingThreshold = 0.3;
   __block int cnt = 0;
   [indexSet enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL *stop) {
     NSArray *nodes = sections[cnt++];
-    std::vector<CGSize> v(nodes.count);
+    std::vector<CGSize> v;
+    v.reserve(nodes.count);
 
     for (int i = 0; i < nodes.count; i++) {
       v.push_back([nodes[i] CGSizeValue]);