Initial refactoring to enable reuse of SkiaDisplayList

on a per RenderNode basis. With Skia renderer we
see 30% speed improvement in Invalidate Tree UI Jank test,
when SkiaDisplayList objects are reused.

Test: manually built and run on angler-eng.
Change-Id: Ie4ec50ddb2015150e3ec678dde7ebed0c8d90067

core/java/android/view/DisplayListCanvas.java

@@ -52,9 +52,10 @@ public class DisplayListCanvas extends Canvas {
         if (node == null) throw new IllegalArgumentException("node cannot be null");
         DisplayListCanvas canvas = sPool.acquire();
         if (canvas == null) {
-            canvas = new DisplayListCanvas(width, height);
+            canvas = new DisplayListCanvas(node, width, height);
         } else {
-            nResetDisplayListCanvas(canvas.mNativeCanvasWrapper, width, height);
+            nResetDisplayListCanvas(canvas.mNativeCanvasWrapper, node.mNativeRenderNode,
+                    width, height);
         }
         canvas.mNode = node;
         canvas.mWidth = width;
@@ -80,8 +81,8 @@ public class DisplayListCanvas extends Canvas {
     // Constructors
     ///////////////////////////////////////////////////////////////////////////
 
-    private DisplayListCanvas(int width, int height) {
-        super(nCreateDisplayListCanvas(width, height));
+    private DisplayListCanvas(@NonNull RenderNode node, int width, int height) {
+        super(nCreateDisplayListCanvas(node.mNativeRenderNode, width, height));
         mDensity = 0; // disable bitmap density scaling
     }
 
@@ -231,9 +232,10 @@ public class DisplayListCanvas extends Canvas {
     }
 
     @FastNative
-    private static native long nCreateDisplayListCanvas(int width, int height);
+    private static native long nCreateDisplayListCanvas(long node, int width, int height);
     @FastNative
-    private static native void nResetDisplayListCanvas(long canvas, int width, int height);
+    private static native void nResetDisplayListCanvas(long canvas, long node,
+            int width, int height);
     @FastNative
     private static native int nGetMaximumTextureWidth();
     @FastNative

core/jni/android_view_DisplayListCanvas.cpp

@@ -169,14 +169,16 @@ static jlong android_view_DisplayListCanvas_finishRecording(JNIEnv* env,
 }
 
 static jlong android_view_DisplayListCanvas_createDisplayListCanvas(JNIEnv* env, jobject clazz,
-        jint width, jint height) {
-    return reinterpret_cast<jlong>(Canvas::create_recording_canvas(width, height));
+        jlong renderNodePtr, jint width, jint height) {
+    RenderNode* renderNode = reinterpret_cast<RenderNode*>(renderNodePtr);
+    return reinterpret_cast<jlong>(Canvas::create_recording_canvas(width, height, renderNode));
 }
 
 static void android_view_DisplayListCanvas_resetDisplayListCanvas(JNIEnv* env, jobject clazz,
-        jlong canvasPtr, jint width, jint height) {
+        jlong canvasPtr, jlong renderNodePtr, jint width, jint height) {
     Canvas* canvas = reinterpret_cast<Canvas*>(canvasPtr);
-    canvas->resetRecording(width, height);
+    RenderNode* renderNode = reinterpret_cast<RenderNode*>(renderNodePtr);
+    canvas->resetRecording(width, height, renderNode);
 }
 
 
@@ -229,8 +231,8 @@ static JNINativeMethod gMethods[] = {
     { "nFinishRecording",   "(J)J",            (void*) android_view_DisplayListCanvas_finishRecording },
     { "nDrawRenderNode",    "(JJ)V",           (void*) android_view_DisplayListCanvas_drawRenderNode },
 
-    { "nCreateDisplayListCanvas", "(II)J",     (void*) android_view_DisplayListCanvas_createDisplayListCanvas },
-    { "nResetDisplayListCanvas", "(JII)V",     (void*) android_view_DisplayListCanvas_resetDisplayListCanvas },
+    { "nCreateDisplayListCanvas", "(JII)J",     (void*) android_view_DisplayListCanvas_createDisplayListCanvas },
+    { "nResetDisplayListCanvas", "(JJII)V",     (void*) android_view_DisplayListCanvas_resetDisplayListCanvas },
 
     { "nDrawLayer",               "(JJ)V",     (void*) android_view_DisplayListCanvas_drawLayer },
 

libs/hwui/RecordingCanvas.cpp

@@ -36,7 +36,7 @@ RecordingCanvas::~RecordingCanvas() {
             "Destroyed a RecordingCanvas during a record!");
 }
 
-void RecordingCanvas::resetRecording(int width, int height) {
+void RecordingCanvas::resetRecording(int width, int height, RenderNode* node) {
     LOG_ALWAYS_FATAL_IF(mDisplayList,
             "prepareDirty called a second time during a recording!");
     mDisplayList = new DisplayList();

libs/hwui/RecordingCanvas.h

@@ -50,7 +50,7 @@ public:
     RecordingCanvas(size_t width, size_t height);
     virtual ~RecordingCanvas();
 
-    virtual void resetRecording(int width, int height) override;
+    virtual void resetRecording(int width, int height, RenderNode* node = nullptr) override;
     virtual WARN_UNUSED_RESULT DisplayList* finishRecording() override;
 // ----------------------------------------------------------------------------
 // MISC HWUI OPERATIONS - TODO: CATEGORIZE

libs/hwui/SkiaCanvas.h

@@ -48,7 +48,8 @@ public:
         return mCanvas.get();
     }
 
-    virtual void resetRecording(int width, int height) override {
+    virtual void resetRecording(int width, int height,
+            uirenderer::RenderNode* renderNode) override {
         LOG_ALWAYS_FATAL("SkiaCanvas cannot be reset as a recording canvas");
     }
 

libs/hwui/hwui/Canvas.cpp

@@ -17,6 +17,7 @@
 #include "Canvas.h"
 
 #include "RecordingCanvas.h"
+#include "RenderNode.h"
 #include "MinikinUtils.h"
 #include "Paint.h"
 #include "Typeface.h"
@@ -25,7 +26,7 @@
 
 namespace android {
 
-Canvas* Canvas::create_recording_canvas(int width, int height) {
+Canvas* Canvas::create_recording_canvas(int width, int height, uirenderer::RenderNode* renderNode) {
     return new uirenderer::RecordingCanvas(width, height);
 }
 

libs/hwui/hwui/Canvas.h

@@ -74,7 +74,23 @@ public:
 
     static Canvas* create_canvas(const SkBitmap& bitmap);
 
-    static WARN_UNUSED_RESULT Canvas* create_recording_canvas(int width, int height);
+    /**
+     *  Create a new Canvas object that records view system drawing operations for deferred
+     *  rendering. A canvas returned by this call supports calls to the resetRecording(...) and
+     *  finishRecording() calls.  The latter call returns a DisplayList that is specific to the
+     *  RenderPipeline defined by Properties::getRenderPipelineType().
+     *
+     *  @param width of the requested Canvas.
+     *  @param height of the requested Canvas.
+     *  @param renderNode is an optional parameter that specifies the node that will consume the
+     *      DisplayList produced by the returned Canvas.  This enables the reuse of select C++
+     *      objects as a speed optimization.
+     *  @return new non-null Canvas Object.  The type of DisplayList produced by this canvas is
+            determined based on Properties::getRenderPipelineType().
+     *
+     */
+    static WARN_UNUSED_RESULT Canvas* create_recording_canvas(int width, int height,
+            uirenderer::RenderNode* renderNode = nullptr);
 
     /**
      *  Create a new Canvas object which delegates to an SkCanvas.
@@ -83,7 +99,8 @@ public:
      *      delegated to this object. This function will call ref() on the
      *      SkCanvas, and the returned Canvas will unref() it upon
      *      destruction.
-     *  @return new Canvas object. Will not return NULL.
+     *  @return new non-null Canvas Object.  The type of DisplayList produced by this canvas is
+     *      determined based on  Properties::getRenderPipelineType().
      */
     static Canvas* create_canvas(SkCanvas* skiaCanvas);
 
@@ -112,7 +129,8 @@ public:
 // View System operations (not exposed in public Canvas API)
 // ----------------------------------------------------------------------------
 
-    virtual void resetRecording(int width, int height) = 0;
+    virtual void resetRecording(int width, int height,
+            uirenderer::RenderNode* renderNode = nullptr) = 0;
     virtual uirenderer::DisplayList* finishRecording() = 0;
     virtual void insertReorderBarrier(bool enableReorder) = 0;