Simplify subtree (now subsequence) caching

Source/platform/graphics/paint/DisplayItemListTest.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 "config.h"
 #include "platform/graphics/paint/DisplayItemList.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/CachedDisplayItem.h"
@@ skipping 440 matching lines @@
         TestDisplayItem(container1, foregroundDrawingType));
 }
 
 TEST_F(DisplayItemListTest, CachedSubtreeSwapOrder)
 {
     TestDisplayItemClient container1("container1");
     TestDisplayItemClient content1("content1");
     TestDisplayItemClient container2("container2");
     TestDisplayItemClient content2("content2");
     GraphicsContext context(&displayItemList());
-    const int backgroundPaintPhase = backgroundDrawingType - DisplayItem::DrawingPaintPhaseFirst;
-    const int foregroundPaintPhase = foregroundDrawingType - DisplayItem::DrawingPaintPhaseFirst;
 
     {
-        SubtreeRecorder r(context, container1, backgroundPaintPhase);
-        EXPECT_FALSE(r.canUseCache());
+        SubtreeRecorder r(context, container1);
         drawRect(context, container1, backgroundDrawingType, FloatRect(100, 100, 100, 100));
         drawRect(context, content1, backgroundDrawingType, FloatRect(100, 100, 50, 200));
-    }
-    {
-        SubtreeRecorder r(context, container1, foregroundPaintPhase);
-        EXPECT_FALSE(r.canUseCache());
         drawRect(context, content1, foregroundDrawingType, FloatRect(100, 100, 50, 200));
         drawRect(context, container1, foregroundDrawingType, FloatRect(100, 100, 100, 100));
     }
     {
-        SubtreeRecorder r(context, container2, backgroundPaintPhase);
-        EXPECT_FALSE(r.canUseCache());
+        SubtreeRecorder r(context, container2);
         drawRect(context, container2, backgroundDrawingType, FloatRect(100, 200, 100, 100));
         drawRect(context, content2, backgroundDrawingType, FloatRect(100, 200, 50, 200));
-    }
-    {
-        SubtreeRecorder r(context, container2, foregroundPaintPhase);
-        EXPECT_FALSE(r.canUseCache());
         drawRect(context, content2, foregroundDrawingType, FloatRect(100, 200, 50, 200));
         drawRect(context, container2, foregroundDrawingType, FloatRect(100, 200, 100, 100));
     }
     displayItemList().commitNewDisplayItems();
 
-    EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 16,
-        TestDisplayItem(container1, DisplayItem::paintPhaseToBeginSubtreeType(backgroundPaintPhase)),
+    EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 12,
+        TestDisplayItem(container1, DisplayItem::BeginSubtree),
         TestDisplayItem(container1, backgroundDrawingType),
         TestDisplayItem(content1, backgroundDrawingType),
-        TestDisplayItem(container1, DisplayItem::paintPhaseToEndSubtreeType(backgroundPaintPhase)),
-
-        TestDisplayItem(container1, DisplayItem::paintPhaseToBeginSubtreeType(foregroundPaintPhase)),
         TestDisplayItem(content1, foregroundDrawingType),
         TestDisplayItem(container1, foregroundDrawingType),
-        TestDisplayItem(container1, DisplayItem::paintPhaseToEndSubtreeType(foregroundPaintPhase)),
+        TestDisplayItem(container1, DisplayItem::EndSubtree),
 
-        TestDisplayItem(container2, DisplayItem::paintPhaseToBeginSubtreeType(backgroundPaintPhase)),
+        TestDisplayItem(container2, DisplayItem::BeginSubtree),
         TestDisplayItem(container2, backgroundDrawingType),
         TestDisplayItem(content2, backgroundDrawingType),
-        TestDisplayItem(container2, DisplayItem::paintPhaseToEndSubtreeType(backgroundPaintPhase)),
-
-        TestDisplayItem(container2, DisplayItem::paintPhaseToBeginSubtreeType(foregroundPaintPhase)),
         TestDisplayItem(content2, foregroundDrawingType),
         TestDisplayItem(container2, foregroundDrawingType),
-        TestDisplayItem(container2, DisplayItem::paintPhaseToEndSubtreeType(foregroundPaintPhase)));
+        TestDisplayItem(container2, DisplayItem::EndSubtree));
 
     // Simulate the situation when container1 e.g. gets a z-index that is now greater than container2.
-    displayItemList().createAndAppend<CachedDisplayItem>(container2, DisplayItem::paintPhaseToCachedSubtreeType(backgroundPaintPhase));
+    EXPECT_TRUE(SubtreeRecorder::useCachedSubtreeIfPossible(context, container2));
     EXPECT_EQ((size_t)1, newPaintListBeforeUpdate().size());
-    EXPECT_TRUE(newPaintListBeforeUpdate().last().isCachedSubtree());
-    displayItemList().createAndAppend<CachedDisplayItem>(container2, DisplayItem::paintPhaseToCachedSubtreeType(foregroundPaintPhase));
+    EXPECT_TRUE(newPaintListBeforeUpdate().last().type() == DisplayItem::CachedSubtree);
+
+    EXPECT_TRUE(SubtreeRecorder::useCachedSubtreeIfPossible(context, container1));
     EXPECT_EQ((size_t)2, newPaintListBeforeUpdate().size());
-    EXPECT_TRUE(newPaintListBeforeUpdate().last().isCachedSubtree());
-
-    displayItemList().createAndAppend<CachedDisplayItem>(container1, DisplayItem::paintPhaseToCachedSubtreeType(backgroundPaintPhase));
-    EXPECT_EQ((size_t)3, newPaintListBeforeUpdate().size());
-    EXPECT_TRUE(newPaintListBeforeUpdate().last().isCachedSubtree());
-    displayItemList().createAndAppend<CachedDisplayItem>(container1, DisplayItem::paintPhaseToCachedSubtreeType(foregroundPaintPhase));
-    EXPECT_EQ((size_t)4, newPaintListBeforeUpdate().size());
-    EXPECT_TRUE(newPaintListBeforeUpdate().last().isCachedSubtree());
+    EXPECT_TRUE(newPaintListBeforeUpdate().last().type() == DisplayItem::CachedSubtree);
     displayItemList().commitNewDisplayItems();
 
-    EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 16,
-        TestDisplayItem(container2, DisplayItem::paintPhaseToBeginSubtreeType(backgroundDrawingType)),
+    EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 12,
+        TestDisplayItem(container2, DisplayItem::BeginSubtree),
         TestDisplayItem(container2, backgroundDrawingType),
         TestDisplayItem(content2, backgroundDrawingType),
-        TestDisplayItem(container2, DisplayItem::paintPhaseToEndSubtreeType(backgroundDrawingType)),
-
-        TestDisplayItem(container2, DisplayItem::paintPhaseToBeginSubtreeType(foregroundDrawingType)),
         TestDisplayItem(content2, foregroundDrawingType),
         TestDisplayItem(container2, foregroundDrawingType),
-        TestDisplayItem(container2, DisplayItem::paintPhaseToEndSubtreeType(foregroundDrawingType)),
+        TestDisplayItem(container2, DisplayItem::EndSubtree),
 
-        TestDisplayItem(container1, DisplayItem::paintPhaseToBeginSubtreeType(backgroundDrawingType)),
+        TestDisplayItem(container1, DisplayItem::BeginSubtree),
         TestDisplayItem(container1, backgroundDrawingType),
         TestDisplayItem(content1, backgroundDrawingType),
-        TestDisplayItem(container1, DisplayItem::paintPhaseToEndSubtreeType(backgroundDrawingType)),
-
-        TestDisplayItem(container1, DisplayItem::paintPhaseToBeginSubtreeType(foregroundDrawingType)),
         TestDisplayItem(content1, foregroundDrawingType),
         TestDisplayItem(container1, foregroundDrawingType),
-        TestDisplayItem(container1, DisplayItem::paintPhaseToEndSubtreeType(foregroundDrawingType)));
+        TestDisplayItem(container1, DisplayItem::EndSubtree));
+}
+
+TEST_F(DisplayItemListTest, CachedNestedSubtreeUpdate)
+{
+    TestDisplayItemClient container1("container1");
+    TestDisplayItemClient content1("content1");
+    TestDisplayItemClient container2("container2");
+    TestDisplayItemClient content2("content2");
+    GraphicsContext context(&displayItemList());
+
+    {
+        SubtreeRecorder r(context, container1);
+        drawRect(context, container1, backgroundDrawingType, FloatRect(100, 100, 100, 100));
+        {
+            SubtreeRecorder r(context, content1);
+            drawRect(context, content1, backgroundDrawingType, FloatRect(100, 100, 50, 200));
+            drawRect(context, content1, foregroundDrawingType, FloatRect(100, 100, 50, 200));
+        }
+        drawRect(context, container1, foregroundDrawingType, FloatRect(100, 100, 100, 100));
+    }
+    {
+        SubtreeRecorder r(context, container2);
+        drawRect(context, container2, backgroundDrawingType, FloatRect(100, 200, 100, 100));
+        {
+            SubtreeRecorder r(context, content2);
+            drawRect(context, content2, backgroundDrawingType, FloatRect(100, 200, 50, 200));
+        }
+    }
+    displayItemList().commitNewDisplayItems();
+
+    EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 14,
+        TestDisplayItem(container1, DisplayItem::BeginSubtree),
+        TestDisplayItem(container1, backgroundDrawingType),
+        TestDisplayItem(content1, DisplayItem::BeginSubtree),
+        TestDisplayItem(content1, backgroundDrawingType),
+        TestDisplayItem(content1, foregroundDrawingType),
+        TestDisplayItem(content1, DisplayItem::EndSubtree),
+        TestDisplayItem(container1, foregroundDrawingType),
+        TestDisplayItem(container1, DisplayItem::EndSubtree),
+
+        TestDisplayItem(container2, DisplayItem::BeginSubtree),
+        TestDisplayItem(container2, backgroundDrawingType),
+        TestDisplayItem(content2, DisplayItem::BeginSubtree),
+        TestDisplayItem(content2, backgroundDrawingType),
+        TestDisplayItem(content2, DisplayItem::EndSubtree),
+        TestDisplayItem(container2, DisplayItem::EndSubtree));
+
+    // Invalidate container1 but not content1.
+    displayItemList().invalidate(container1.displayItemClient());
+
+    // Container2 itself now becomes empty (but still has the 'content2' child), and chooses not to output subtree info.
+    displayItemList().invalidate(container2.displayItemClient());
+    displayItemList().invalidate(content2.displayItemClient());
+    EXPECT_FALSE(SubtreeRecorder::useCachedSubtreeIfPossible(context, container2));
+    EXPECT_FALSE(SubtreeRecorder::useCachedSubtreeIfPossible(context, content2));
+    // Content2 now outputs foreground only.
+    {
+        SubtreeRecorder r(context, content2);
+        drawRect(context, content2, foregroundDrawingType, FloatRect(100, 200, 50, 200));
+    }
+    EXPECT_EQ((size_t)3, newPaintListBeforeUpdate().size());
+
+    // Repaint container1 with foreground only.
+    {
+        EXPECT_FALSE(SubtreeRecorder::useCachedSubtreeIfPossible(context, container1));
+        SubtreeRecorder r(context, container1);
+
+        // Use cached subtree of content1.
+        EXPECT_TRUE(SubtreeRecorder::useCachedSubtreeIfPossible(context, content1));
+        EXPECT_EQ((size_t)5, newPaintListBeforeUpdate().size());
+        EXPECT_TRUE(newPaintListBeforeUpdate().last().type() == DisplayItem::CachedSubtree);
+
+        drawRect(context, container1, foregroundDrawingType, FloatRect(100, 100, 100, 100));
+    }
+    EXPECT_EQ((size_t)7, newPaintListBeforeUpdate().size());

[chrishtr, 2015/08/25 23:48:19]

Check that newPaintListBeforeUpdate() has cached subtree items?

[Xianzhu, 2015/08/26 23:21:06]

Done.

+
+    displayItemList().commitNewDisplayItems();
+
+    EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 10,
+        TestDisplayItem(content2, DisplayItem::BeginSubtree),
+        TestDisplayItem(content2, foregroundDrawingType),
+        TestDisplayItem(content2, DisplayItem::EndSubtree),
+
+        TestDisplayItem(container1, DisplayItem::BeginSubtree),
+        TestDisplayItem(content1, DisplayItem::BeginSubtree),
+        TestDisplayItem(content1, backgroundDrawingType),
+        TestDisplayItem(content1, foregroundDrawingType),
+        TestDisplayItem(content1, DisplayItem::EndSubtree),
+        TestDisplayItem(container1, foregroundDrawingType),
+        TestDisplayItem(container1, DisplayItem::EndSubtree));
 }
 
 TEST_F(DisplayItemListTest, Scope)
 {
     TestDisplayItemClient multicol("multicol");
     TestDisplayItemClient content("content");
     GraphicsContext context(&displayItemList());
 
     FloatRect rect1(100, 100, 50, 50);
     FloatRect rect2(150, 100, 50, 50);
@@ skipping 121 matching lines @@
     drawRect(context, third, backgroundDrawingType, FloatRect(0, 0, 100, 100));
     displayItemList().commitNewDisplayItems();
 
     // Empty clips should have been optimized out.
     EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 2,
         TestDisplayItem(first, backgroundDrawingType),
         TestDisplayItem(third, backgroundDrawingType));
 }
 
 } // namespace blink