Enable subsequence caching for spv2

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

 // 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.
 
 #include "platform/graphics/paint/PaintController.h"
 
 #include "platform/TraceEvent.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/graphics/paint/DrawingDisplayItem.h"
 #include "third_party/skia/include/core/SkPictureAnalyzer.h"
@@ skipping 58 matching lines @@
         // is the same as the cached.
         return false;
     }
 #endif
 
     return true;
 }
 
 bool PaintController::useCachedSubsequenceIfPossible(const DisplayItemClient& client)
 {
-    // TODO(crbug.com/596983): Implement subsequence caching for spv2.
-    // The problem is in copyCachedSubsequence() which fails to handle PaintChunkProperties
-    // of chunks containing cached display items. We need to find the previous
-    // PaintChunkProperties and ensure they are valid in the current paint property tree.
-    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
-        return false;
-
     if (displayItemConstructionIsDisabled() || subsequenceCachingIsDisabled())
         return false;
 
     if (!clientCacheIsValid(client))
         return false;
 
 #if DCHECK_IS_ON()
     if (RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled() && isCheckingUnderInvalidation()) {
         // We are checking under-invalidation of an ancestor subsequence enclosing this one.
         // The ancestor subsequence is supposed to have already "copied", so we should let the
@@ skipping 77 matching lines @@
 
         if (displayItem.getType() == DisplayItem::Subsequence) {
             m_currentSubsequenceClients.append(&displayItem.client());
         } else if (displayItem.getType() == DisplayItem::EndSubsequence) {
             CHECK(m_currentSubsequenceClients.last() == &displayItem.client());
             m_currentSubsequenceClients.removeLast();
         }
     }
 #endif
 
+    if (isSkippingCache())
+        displayItem.setSkippedCache();
+
 #if DCHECK_IS_ON()
     // Verify noop begin/end pairs have been removed.
     if (m_newDisplayItemList.size() >= 2 && displayItem.isEnd()) {
         const auto& beginDisplayItem = m_newDisplayItemList[m_newDisplayItemList.size() - 2];
         if (beginDisplayItem.isBegin() && beginDisplayItem.getType() != DisplayItem::Subsequence && !beginDisplayItem.drawsContent())
             DCHECK(!displayItem.isEndAndPairedWith(beginDisplayItem.getType()));
     }
-#endif
 
-    if (isSkippingCache())
-        displayItem.setSkippedCache();
-
-#if DCHECK_IS_ON()
     size_t index = findMatchingItemFromIndex(displayItem.getId(), m_newDisplayItemIndicesByClient, m_newDisplayItemList);
     if (index != kNotFound) {
 #ifndef NDEBUG
         showDebugData();
         WTFLogAlways("DisplayItem %s has duplicated id with previous %s (index=%d)\n",
             displayItem.asDebugString().utf8().data(), m_newDisplayItemList[index].asDebugString().utf8().data(), static_cast<int>(index));
 #endif
         NOTREACHED();
     }
     addItemToIndexIfNeeded(displayItem, m_newDisplayItemList.size() - 1, m_newDisplayItemIndicesByClient);
@@ skipping 140 matching lines @@
         m_underInvalidationCheckingBegin = cachedItemIndex;
 #ifndef NDEBUG
         m_underInvalidationMessagePrefix = "(In CachedSubsequence of " + cachedItem->clientDebugString() + ")";
 #else
         m_underInvalidationMessagePrefix = "(In CachedSubsequence)";
 #endif
     }
 #endif
 
     DisplayItem::Id endSubsequenceId(cachedItem->client(), DisplayItem::EndSubsequence);
+    Vector<PaintChunk>::const_iterator cachedChunk;
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+        cachedChunk = m_currentPaintArtifact.findChunkByDisplayItemIndex(cachedItemIndex);
+        updateCurrentPaintChunkProperties(cachedChunk->id ? &*cachedChunk->id : nullptr, cachedChunk->properties);
+    } else {
+        // This is to avoid compilation error about uninitialized variable on Windows.
+        cachedChunk = m_currentPaintArtifact.paintChunks().begin();
+    }
+
     while (true) {
         DCHECK(cachedItem->hasValidClient());
 #if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
         CHECK(cachedItem->client().isAlive());
 #endif
         ++m_numCachedNewItems;
         bool metEndSubsequence = cachedItem->getId() == endSubsequenceId;
-        if (!DCHECK_IS_ON() || !RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled())
+        if (!DCHECK_IS_ON() || !RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled()) {
+            if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && cachedItemIndex == cachedChunk->endIndex) {
+                ++cachedChunk;
+                updateCurrentPaintChunkProperties(cachedChunk->id ? &*cachedChunk->id : nullptr, cachedChunk->properties);
+            }
             processNewItem(m_newDisplayItemList.appendByMoving(*cachedItem));
+            if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+                DCHECK((!m_newPaintChunks.lastChunk().id && !cachedChunk->id) || m_newPaintChunks.lastChunk().matches(*cachedChunk));
+        }
 
         ++cachedItemIndex;
         if (metEndSubsequence)
             break;
 
         // We should always be able to find the EndSubsequence display item.
         DCHECK(cachedItemIndex < m_currentPaintArtifact.getDisplayItemList().size());
         cachedItem = &m_currentPaintArtifact.getDisplayItemList()[cachedItemIndex];
     }
 
@@ skipping 48 matching lines @@
         if (item.isCacheable())
             item.client().setDisplayItemsCached(m_currentCacheGeneration);
     }
 
     // The new list will not be appended to again so we can release unused memory.
     m_newDisplayItemList.shrinkToFit();
     m_currentPaintArtifact = PaintArtifact(std::move(m_newDisplayItemList), m_newPaintChunks.releasePaintChunks(), gpuAnalyzer.suitableForGpuRasterization());
     resetCurrentListIndices();
     m_outOfOrderItemIndices.clear();
 
+    for (const auto& chunk : m_currentPaintArtifact.paintChunks()) {
+        if (chunk.id)
+            chunk.id->client.setDisplayItemsCached(m_currentCacheGeneration);
+    }
+
     // We'll allocate the initial buffer when we start the next paint.
     m_newDisplayItemList = DisplayItemList(0);
 
 #if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
     CHECK(m_currentSubsequenceClients.isEmpty());
     DisplayItemClient::endShouldKeepAliveAllClients(this);
 #endif
 
 #if DCHECK_IS_ON()
     m_numSequentialMatches = 0;
@@ skipping 109 matching lines @@
 
 void PaintController::showDebugData() const
 {
     WTFLogAlways("current display item list: [%s]\n", displayItemListAsDebugString(m_currentPaintArtifact.getDisplayItemList()).utf8().data());
     WTFLogAlways("new display item list: [%s]\n", displayItemListAsDebugString(m_newDisplayItemList).utf8().data());
 }
 
 #endif // ifndef NDEBUG
 
 } // namespace blink