[SPv2] Rasterization invalidation

third_party/WebKit/Source/platform/graphics/paint/PaintController.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PaintController_h
 #define PaintController_h
 
 #include "platform/PlatformExport.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/IntRect.h"
@@ skipping 60 matching lines @@
         static_assert(WTF::IsSubclass<DisplayItemClass, DisplayItem>::value,
             "Can only createAndAppend subclasses of DisplayItem.");
         static_assert(sizeof(DisplayItemClass) <= kMaximumDisplayItemSize,
             "DisplayItem subclass is larger than kMaximumDisplayItemSize.");
 
         if (displayItemConstructionIsDisabled())
             return;
 
         ensureNewDisplayItemListInitialCapacity();
         DisplayItemClass& displayItem = m_newDisplayItemList.allocateAndConstruct<DisplayItemClass>(std::forward<Args>(args)...);
-        processNewItem(displayItem);
+        processNewItem(displayItem, NewPainting);
     }
 
     // Creates and appends an ending display item to pair with a preceding
     // beginning item iff the display item actually draws content. For no-op
     // items, rather than creating an ending item, the begin item will
     // instead be removed, thereby maintaining brevity of the list. If display
     // item construction is disabled, no list mutations will be performed.
     template <typename DisplayItemClass, typename... Args>
     void endItem(Args&&... args)
     {
@@ skipping 65 matching lines @@
 
 protected:
     PaintController()
         : m_newDisplayItemList(0)
         , m_constructionDisabled(false)
         , m_subsequenceCachingDisabled(false)
         , m_textPainted(false)
         , m_imagePainted(false)
         , m_skippingCacheCount(0)
         , m_numCachedNewItems(0)
+        , m_currentChunkIsFromCachedSubsequence(true)
 #if DCHECK_IS_ON()
         , m_numSequentialMatches(0)
         , m_numOutOfOrderMatches(0)
         , m_numIndexedItems(0)
 #endif
     {
         resetCurrentListIndices();
     }
 
 private:
     friend class PaintControllerTestBase;
     friend class PaintControllerPaintTestBase;
 
     void ensureNewDisplayItemListInitialCapacity()
     {
         if (m_newDisplayItemList.isEmpty()) {
             // TODO(wangxianzhu): Consider revisiting this heuristic.
             m_newDisplayItemList = DisplayItemList(m_currentPaintArtifact.getDisplayItemList().isEmpty() ? kInitialDisplayItemListCapacityBytes : m_currentPaintArtifact.getDisplayItemList().usedCapacityInBytes());
         }
     }
 
     // Set new item state (cache skipping, etc) for a new item.
-    void processNewItem(DisplayItem&);
+    enum NewItemSource { FromCachedItem, FromCachedSubsequence, NewPainting };
+    void processNewItem(DisplayItem&, NewItemSource);
 
     String displayItemListAsDebugString(const DisplayItemList&) const;
 
-    // Indices into PaintList of all DrawingDisplayItems and BeginSubsequenceDisplayItems of each client.
-    // Temporarily used during merge to find out-of-order display items.
-    using DisplayItemIndicesByClientMap = HashMap<const DisplayItemClient*, Vector<size_t>>;
+    // Maps clients to indices of display items or chunks of each client.
+    using IndicesByClientMap = HashMap<const DisplayItemClient*, Vector<size_t>>;
 
-    static size_t findMatchingItemFromIndex(const DisplayItem::Id&, const DisplayItemIndicesByClientMap&, const DisplayItemList&);
-    static void addItemToIndexIfNeeded(const DisplayItem&, size_t index, DisplayItemIndicesByClientMap&);
+    static size_t findMatchingItemFromIndex(const DisplayItem::Id&, const IndicesByClientMap&, const DisplayItemList&);
+    static void addItemToIndexIfNeeded(const DisplayItem&, size_t index, IndicesByClientMap&);
 
     size_t findCachedItem(const DisplayItem::Id&);
     size_t findOutOfOrderCachedItemForward(const DisplayItem::Id&);
     void copyCachedSubsequence(size_t&);
 
     // Resets the indices (e.g. m_nextItemToMatch) of m_currentPaintArtifact.getDisplayItemList()
     // to their initial values. This should be called when the DisplayItemList in m_currentPaintArtifact
     // is newly created, or is changed causing the previous indices to be invalid.
     void resetCurrentListIndices();
 
+    void generateChunkRerasterizationRects(PaintChunk& newChunk);
+    void generateChunkRerasterizationRectsComparingOldChunk(PaintChunk& newChunk, const PaintChunk& oldChunk);
+
 #if DCHECK_IS_ON()
     // The following two methods are for checking under-invalidations
     // (when RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled).
     void showUnderInvalidationError(const char* reason, const DisplayItem& newItem, const DisplayItem* oldItem) const;
     void checkUnderInvalidation();
     bool isCheckingUnderInvalidation() const { return m_underInvalidationCheckingEnd - m_underInvalidationCheckingBegin > 0; }
 #endif
 
     // The last complete paint artifact.
     // In SPv2, this includes paint chunks as well as display items.
@@ skipping 11 matching lines @@
     bool m_subsequenceCachingDisabled;
 
     // Indicates this PaintController has ever had text. It is never reset to false.
     bool m_textPainted;
     bool m_imagePainted;
 
     int m_skippingCacheCount;
 
     int m_numCachedNewItems;
 
-    // Stores indices to valid DrawingDisplayItems in current display list that have not been
-    // matched by CachedDisplayItems during sequential matching. The indexed items will be
+    // Stores indices to valid cacheable display items in m_currentPaintArtifact.displayItemList()
+    // that have not been matched by requests of cached display items (using useCachedDrawingIfPossible()
+    // and useCachedSubsequenceIfPossible()) during sequential matching . The indexed items will be
     // matched by later out-of-order requests of cached display items. This ensures that when
     // out-of-order cached display items are requested, we only traverse at most once over
     // the current display list looking for potential matches. Thus we can ensure that the
     // algorithm runs in linear time.
-    DisplayItemIndicesByClientMap m_outOfOrderItemIndices;
+    IndicesByClientMap m_outOfOrderItemIndices;
 
     // The next item in the current list for sequential match.
     size_t m_nextItemToMatch;
 
     // The next item in the current list to be indexed for out-of-order cache requests.
     size_t m_nextItemToIndex;
 
+    // Similar to m_outOfOrderItemIndices but
+    // - the indices are chunk indices in m_currentPaintArtifacts.paintChunks();
+    // - chunks are matched not only for requests of cached display items, but also non-cached display items.
+    IndicesByClientMap m_outOfOrderChunkIndices;
+
+    bool m_currentChunkIsFromCachedSubsequence;
+    size_t m_nextChunkToMatch;
+
     DisplayItemClient::CacheGenerationOrInvalidationReason m_currentCacheGeneration;
 
 #if DCHECK_IS_ON()
     int m_numSequentialMatches;
     int m_numOutOfOrderMatches;
     int m_numIndexedItems;
 
     // This is used to check duplicated ids during createAndAppend().
-    DisplayItemIndicesByClientMap m_newDisplayItemIndicesByClient;
+    IndicesByClientMap m_newDisplayItemIndicesByClient;
 
     // These are set in useCachedDrawingIfPossible() and useCachedSubsequenceIfPossible()
     // when we could use cached drawing or subsequence and under-invalidation checking is on,
     // indicating the begin and end of the cached drawing or subsequence in the current list.
     // The functions return false to let the client do actual painting, and PaintController
     // will check if the actual painting results are the same as the cached.
     size_t m_underInvalidationCheckingBegin;
     size_t m_underInvalidationCheckingEnd;
     // Number of probable under-invalidations that have been skipped temporarily because the
     // mismatching display items may be removed in the future because of no-op pairs or
     // compositing folding.
     int m_skippedProbableUnderInvalidationCount;
     String m_underInvalidationMessagePrefix;
 #endif
 
 #if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
     // A stack recording subsequence clients that are currently painting.
     Vector<const DisplayItemClient*> m_currentSubsequenceClients;
 #endif
 };
 
 } // namespace blink
 
 #endif // PaintController_h