[WEEX-648][iOS]native batch for dom operations generating from JavaScript

ios/sdk/WeexSDK/Sources/Manager/WXComponentManager.h

@@ -262,4 +262,18 @@ void WXPerformBlockSyncOnComponentThread(void (^block)(void));
  */
 - (void)enumerateComponentsUsingBlock:(void (^)(WXComponent *, BOOL *stop))block;
 
+#pragma mark batch mark
+
+/**
+ a start native batch tag for a group of UI operation  , company with performBatchEnd
+ @see performBatchEnd
+ */
+- (void)performBatchBegin;
+
+/**
+ an end native batch tag for a group of UI operation, company with performBatchBegin
+ @see performBatchBegin
+ */
+- (void)performBatchEnd;
+
 @end

ios/sdk/WeexSDK/Sources/Manager/WXComponentManager.mm

@@ -44,7 +44,7 @@
 static NSThread *WXComponentThread;
 
 #define WXAssertComponentExist(component)  WXAssert(component, @"component not exists")
-
+#define MAX_DROP_FRAME_FOR_BATCH   200
 
 @implementation WXComponentManager
 {
@@ -991,8 +991,38 @@ - (void) _printFlexComponentFrame:(WXComponent *)component
 
 - (void)_syncUITasks
 {
-    NSArray<dispatch_block_t> *blocks = _uiTaskQueue;
-    _uiTaskQueue = [NSMutableArray array];
+    static NSInteger _syncUITaskCount = 0;
+    NSInteger mismatchBeginIndex = _uiTaskQueue.count;
+    for (NSInteger i = _uiTaskQueue.count - 1;i >= 0;i --) {
+        if (_uiTaskQueue[i] == WXPerformUITaskBatchEndBlock) {
+            _syncUITaskCount = 0;
+            // clear when find the matches for end and begin tag
+            break;
+        }
+        if (_uiTaskQueue[i] == WXPerformUITaskBatchBeginBlock) {
+            mismatchBeginIndex = i;
+            break;
+        }
+    }
+
+    NSArray<dispatch_block_t> *blocks = nil;
+    if (mismatchBeginIndex == _uiTaskQueue.count) {
+        // here we get end tag or there are not begin and end directives
+    } else {
+        _syncUITaskCount ++;
+        // we only find begin tag but missing end tag,
+        if (_syncUITaskCount > (MAX_DROP_FRAME_FOR_BATCH)) {
+            // when the wait times come to MAX_DROP_FRAME_FOR_BATCH, we will pop all the stashed operation for user experience.
+            mismatchBeginIndex = _uiTaskQueue.count;
+            _syncUITaskCount = 0;
+        }
+    }
+
+    if (mismatchBeginIndex > 0) {
+        blocks = [_uiTaskQueue subarrayWithRange:NSMakeRange(0, mismatchBeginIndex)];
+        [_uiTaskQueue removeObjectsInRange:NSMakeRange(0, blocks.count)];
+    }
+
     dispatch_async(dispatch_get_main_queue(), ^{
         for(dispatch_block_t block in blocks) {
             block();
@@ -1051,6 +1081,27 @@ - (void)enumerateComponentsUsingBlock:(void (^)(WXComponent *, BOOL *stop))block
     }
 }
 
+static void (^WXPerformUITaskBatchBeginBlock)(void) = ^ () {
+#if DEBUG
+    WXLogDebug(@"directive BatchBeginBlock");
+#endif
+};
+static void (^WXPerformUITaskBatchEndBlock)(void) = ^ () {
+#if DEBUG
+    WXLogDebug(@"directive BatchEndBlock");
+#endif
+};
+
+- (void)performBatchBegin
+{
+    [self _addUITask:WXPerformUITaskBatchBeginBlock];
+}
+
+- (void)performBatchEnd
+{
+    [self _addUITask:WXPerformUITaskBatchEndBlock];
+}
+
 - (void)handleDisplayLink {
     [self _handleDisplayLink];
 }

ios/sdk/WeexSDK/Sources/Module/WXDomModule.m

@@ -55,6 +55,8 @@ @implementation WXDomModule
 WX_EXPORT_METHOD(@selector(addRule:rule:))
 WX_EXPORT_METHOD(@selector(getComponentRect:callback:))
 WX_EXPORT_METHOD(@selector(updateComponentData:componentData:callback:))
+WX_EXPORT_METHOD(@selector(beginBatchMark))
+WX_EXPORT_METHOD(@selector(endBatchMark))
 
 - (void)performBlockOnComponentManager:(void(^)(WXComponentManager *))block
 {
@@ -82,6 +84,20 @@ - (void)performSelectorOnRuleManager:(void(^)(void))block{
     });
 }
 
+- (void)beginBatchMark
+{
+    [self performBlockOnComponentManager:^(WXComponentManager *manager) {
+        [manager performBatchBegin];
+    }];
+}
+
+- (void)endBatchMark
+{
+    [self performBlockOnComponentManager:^(WXComponentManager * manager) {
+        [manager performBatchEnd];
+    }];
+}
+
 - (NSThread *)targetExecuteThread
 {
     return [WXComponentManager componentThread];