fix(ios): delete the old useless cache logic for list and waterfall

renderer/native/ios/renderer/HippyUIManager.h

@@ -96,9 +96,6 @@
 /// Get all rootView
 - (NSArray<__kindof UIView *> *)rootViews;
 
-/// Purge view from superView
-- (void)purgeViewsFromComponentTags:(NSArray<NSNumber *> *)componentTag onRootTag:(NSNumber *)rootTag;
-
 /// Update view with props
 - (void)updateView:(NSNumber *)componentTag onRootTag:(NSNumber *)rootTag props:(NSDictionary *)pros;
 

renderer/native/ios/renderer/HippyUIManager.mm

@@ -474,17 +474,6 @@ - (void)purgeChildren:(NSArray<id<HippyComponent>> *)children
     }
 }
 
-- (void)purgeViewsFromComponentTags:(NSArray<NSNumber *> *)componentTags onRootTag:(NSNumber *)rootTag {
-    for (NSNumber *componentTag in componentTags) {
-        UIView *view = [self viewForHippyTag:componentTag onRootTag:rootTag];
-        HippyComponentMap *componentMap = _viewRegistry;
-        NativeRenderTraverseViewNodes(view, ^(id<HippyComponent> subview) {
-            NSAssert(![subview isHippyRootView], @"Root views should not be unregistered");
-            [componentMap removeComponent:subview forRootTag:rootTag];
-        });
-    }
-}
-
 - (void)removeChildren:(NSArray<id<HippyComponent>> *)children fromContainer:(id<HippyComponent>)container {
     for (id<HippyComponent> removedChild in children) {
         [container removeHippySubview:removedChild];

renderer/native/ios/renderer/component/listview/NativeRenderBaseListView.mm

@@ -262,17 +262,6 @@ - (void)collectionView:(UICollectionView *)collectionView
     }
 }
 
-- (void)collectionView:(UICollectionView *)collectionView
-  didEndDisplayingCell:(UICollectionViewCell *)cell
-    forItemAtIndexPath:(NSIndexPath *)indexPath {
-    if ([cell isKindOfClass:[NativeRenderBaseListViewCell class]]) {
-        NativeRenderBaseListViewCell *hpCell = (NativeRenderBaseListViewCell *)cell;
-        if (hpCell.cellView) {
-            [_cachedItems setObject:[hpCell.cellView hippyTag] forKey:indexPath];
-        }
-    }
-}
-
 - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
     NativeRenderBaseListViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kCellIdentifier forIndexPath:indexPath];
 
@@ -290,9 +279,6 @@ - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cell
         [_cachedVisibleCellViews setObject:cellView forKey:shadowView.hippyTag];
     }
 
-    if (cellView) {
-        [_cachedItems removeObjectForKey:indexPath];
-    }
     HippyAssert([cellView conformsToProtocol:@protocol(ViewAppearStateProtocol)],
         @"subviews of NativeRenderBaseListViewCell must conform to protocol ViewAppearStateProtocol");
     cell.cellView = cellView;

renderer/native/ios/renderer/component/waterfalllist/NativeRenderWaterfallView.h

@@ -46,7 +46,6 @@ typedef NS_ENUM(NSInteger, NativeRenderScrollState) {
 @protected
     NativeRenderWaterfallViewDataSource *_dataSource;
 
-    NSMutableDictionary<NSIndexPath *, NSNumber *> *_cachedItems;
     NSMapTable<NSNumber *, UIView *> *_cachedVisibleCellViews;
 
     NativeRenderHeaderRefresh *_headerRefreshView;
@@ -115,10 +114,6 @@ typedef NS_ENUM(NSInteger, NativeRenderScrollState) {
 @property (nonatomic, copy) HippyDirectEventBlock onRefresh;
 @property (nonatomic, copy) HippyDirectEventBlock onExposureReport;
 
-- (NSUInteger)maxCachedItemCount;
-
-- (NSArray<NSIndexPath *> *)findFurthestIndexPathsFromScreen;
-
 /**
  * Initial collection view
  */

renderer/native/ios/renderer/component/waterfalllist/NativeRenderWaterfallView.mm

@@ -68,7 +68,6 @@ - (instancetype)initWithFrame:(CGRect)frame {
         self.backgroundColor = [UIColor clearColor];
         _scrollListeners = [NSHashTable weakObjectsHashTable];
         _scrollEventThrottle = 100.f;
-        _cachedItems = [NSMutableDictionary dictionary];
         _cachedVisibleCellViews = [NSMapTable strongToWeakObjectsMapTable];
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didReceiveMemoryWarning) name:UIApplicationDidReceiveMemoryWarningNotification object:nil];
         [self initCollectionView];
@@ -172,65 +171,6 @@ - (void)setContainBannerView:(BOOL)containBannerView {
 
 #pragma mark Setter & Getter
 
-- (NSUInteger)maxCachedItemCount {
-    return NSUIntegerMax;
-}
-
-- (NSUInteger)differenceFromIndexPath:(NSIndexPath *)indexPath1 againstAnother:(NSIndexPath *)indexPath2 {
-    NSAssert([NSThread mainThread], @"must be in main thread");
-    long diffCount = 0;
-    for (NSUInteger index = MIN([indexPath1 section], [indexPath2 section]); index < MAX([indexPath1 section], [indexPath2 section]); index++) {
-        diffCount += [_collectionView numberOfItemsInSection:index];
-    }
-    diffCount = diffCount + [indexPath1 row] - [indexPath2 row];
-    return abs(diffCount);
-}
-
-- (NSInteger)differenceFromIndexPath:(NSIndexPath *)indexPath againstVisibleIndexPaths:(NSArray<NSIndexPath *> *)visibleIndexPaths {
-    NSIndexPath *firstIndexPath = [visibleIndexPaths firstObject];
-    NSIndexPath *lastIndexPath = [visibleIndexPaths lastObject];
-    NSUInteger diffFirst = [self differenceFromIndexPath:indexPath againstAnother:firstIndexPath];
-    NSUInteger diffLast = [self differenceFromIndexPath:indexPath againstAnother:lastIndexPath];
-    return MIN(diffFirst, diffLast);
-}
-
-- (NSArray<NSIndexPath *> *)findFurthestIndexPathsFromScreen {
-    NSUInteger visibleItemsCount = [[self.collectionView visibleCells] count];
-    NSUInteger maxCachedItemCount = [self maxCachedItemCount] == NSUIntegerMax ? visibleItemsCount * 3 : [self maxCachedItemCount];
-    NSUInteger cachedCount = [_cachedItems count];
-    NSInteger cachedCountToRemove = cachedCount > maxCachedItemCount ? cachedCount - maxCachedItemCount : 0;
-    if (0 != cachedCountToRemove) {
-        NSArray<NSIndexPath *> *visibleIndexPaths = [_collectionView indexPathsForVisibleItems];
-        NSArray<NSIndexPath *> *sortedCachedItemKey = [[_cachedItems allKeys] sortedArrayUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {
-            NSIndexPath *ip1 = obj1;
-            NSIndexPath *ip2 = obj2;
-            NSUInteger ip1Diff = [self differenceFromIndexPath:ip1 againstVisibleIndexPaths:visibleIndexPaths];
-            NSUInteger ip2Diff = [self differenceFromIndexPath:ip2 againstVisibleIndexPaths:visibleIndexPaths];
-            if (ip1Diff > ip2Diff) {
-                return NSOrderedAscending;
-            }
-            else if (ip1Diff < ip2Diff) {
-                return NSOrderedDescending;
-            }
-            else {
-                return NSOrderedSame;
-            }
-        }];
-        NSArray<NSIndexPath *> *result = [sortedCachedItemKey subarrayWithRange:NSMakeRange(0, cachedCountToRemove)];
-        return result;
-    }
-    return nil;
-}
-
-- (void)purgeFurthestIndexPathsFromScreen {
-    NSArray<NSIndexPath *> *furthestIndexPaths = [self findFurthestIndexPathsFromScreen];
-    //purge view
-    NSArray<NSNumber *> *objects = [_cachedItems objectsForKeys:furthestIndexPaths notFoundMarker:@(-1)];
-    [self.renderImpl purgeViewsFromComponentTags:objects onRootTag:self.rootTag];
-    //purge cache
-    [_cachedItems removeObjectsForKeys:furthestIndexPaths];
-}
-
 - (void)setContentInset:(UIEdgeInsets)contentInset {
     _contentInset = contentInset;
 
@@ -314,19 +254,6 @@ - (void)didUpdateHippySubviews {
     // Do nothing, as subviews is managed by `insertHippySubview:atIndex:` or lazy-created
 }
 
-- (void)removeFromHippySuperview {
-    [super removeFromHippySuperview];
-    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(purgeFurthestIndexPathsFromScreen) object:nil];
-    [self purgeFurthestIndexPathsFromScreen];
-}
-
-- (void)didMoveToWindow {
-    if (!self.window) {
-        [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(purgeFurthestIndexPathsFromScreen) object:nil];
-        [self purgeFurthestIndexPathsFromScreen];
-    }
-}
-
 #pragma mark - UICollectionViewDataSource
 - (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
     return [_dataSource numberOfSection];
@@ -352,12 +279,8 @@ - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cell
         [_cachedVisibleCellViews setObject:cellView forKey:shadowView.hippyTag];
     }
 
-    if (cellView) {
-        [_cachedItems removeObjectForKey:indexPath];
-    }
     cell.cellView = cellView;
     cellView.parent = self;
-
     return cell;
 }
 
@@ -383,17 +306,6 @@ - (void)collectionView:(UICollectionView *)collectionView
     }
 }
 
-- (void)collectionView:(UICollectionView *)collectionView
-  didEndDisplayingCell:(UICollectionViewCell *)cell
-    forItemAtIndexPath:(NSIndexPath *)indexPath {
-    if ([cell isKindOfClass:[NativeRenderWaterfallViewCell class]]) {
-        NativeRenderWaterfallViewCell *hpCell = (NativeRenderWaterfallViewCell *)cell;
-        if (hpCell.cellView) {
-            [_cachedItems setObject:[hpCell.cellView hippyTag] forKey:indexPath];
-        }
-    }
-}
-
 #pragma mark - NativeRenderCollectionViewDelegateWaterfallLayout
 
 - (CGSize)collectionView:(UICollectionView *)collectionView
@@ -462,8 +374,6 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
             [scrollViewListener scrollViewDidScroll:scrollView];
         }
     }
-    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(purgeFurthestIndexPathsFromScreen) object:nil];
-    [self performSelector:@selector(purgeFurthestIndexPathsFromScreen) withObject:nil afterDelay:delayForPurgeView];
     [_headerRefreshView scrollViewDidScroll];
     [_footerRefreshView scrollViewDidScroll];
 }
@@ -743,11 +653,7 @@ - (void)didReceiveMemoryWarning {
 }
 
 - (void)cleanUpCachedItems {
-    //purge view
-    NSArray<NSNumber *> *objects = [_cachedItems allValues];
-    [self.renderImpl purgeViewsFromComponentTags:objects onRootTag:self.rootTag];
-    //purge cache
-    [_cachedItems removeAllObjects];
+    // nop
 }
 
 @end