commit c4c9870953037be94da00ac9db887d171f6e479c
author commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Mon Apr 22 14:28:01 2013 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Mon Apr 22 14:28:01 2013 +0000
tree 3b23c2fd0a4de6ebb38d48b9371a76b9a50296d8
parent 73c0abc2affdd5703f66c777e1cb3199179f3a09

Adding optimization to avoid image copy in SkSurface copy on write when content is discardable

This patch also adds code to SkDeferredCanvas to trigger the optimization.

TEST=DeferredSurfaceCopy bench, Surface unit test
R=reed@google.com

Author: junov@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14063015

git-svn-id: http://skia.googlecode.com/svn/trunk@8797 2bbb7eff-a529-9590-31e7-b0007b416f81

src/utils/SkDeferredCanvas.cpp

diff --git a/src/utils/SkDeferredCanvas.cpp b/src/utils/SkDeferredCanvas.cpp
index 42e9537..c181818 100644
--- a/src/utils/SkDeferredCanvas.cpp
+++ b/src/utils/SkDeferredCanvas.cpp
@@ -248,6 +248,7 @@
     SkSurface* fSurface;
     SkDeferredCanvas::NotificationClient* fNotificationClient;
     bool fFreshFrame;
+    bool fCanDiscardCanvasContents;
     size_t fMaxRecordingStorageBytes;
     size_t fPreviousStorageAllocated;
     size_t fBitmapSizeThreshold;
@@ -281,6 +282,7 @@
 void DeferredDevice::init() {
     fRecordingCanvas = NULL;
     fFreshFrame = true;
+    fCanDiscardCanvasContents = false;
     fPreviousStorageAllocated = 0;
     fBitmapSizeThreshold = kDeferredCanvasBitmapSizeThreshold;
     fMaxRecordingStorageBytes = kDefaultMaxRecordingStorageBytes;
@@ -312,11 +314,14 @@
 }
 
 void DeferredDevice::skipPendingCommands() {
-    if (!fRecordingCanvas->isDrawingToLayer() && fPipeController.hasPendingCommands()) {
-        fFreshFrame = true;
-        flushPendingCommands(kSilent_PlaybackMode);
-        if (fNotificationClient) {
-            fNotificationClient->skippedPendingDrawCommands();
+    if (!fRecordingCanvas->isDrawingToLayer()) {
+        fCanDiscardCanvasContents = true;
+        if (fPipeController.hasPendingCommands()) {
+            fFreshFrame = true;
+            flushPendingCommands(kSilent_PlaybackMode);
+            if (fNotificationClient) {
+                fNotificationClient->skippedPendingDrawCommands();
+            }
         }
     }
 }
@@ -335,8 +340,18 @@
     if (!fPipeController.hasPendingCommands()) {
         return;
     }
-    if (playbackMode == kNormal_PlaybackMode && fNotificationClient) {
-        fNotificationClient->prepareForDraw();
+    if (playbackMode == kNormal_PlaybackMode) {
+        if (NULL != fNotificationClient) {
+            fNotificationClient->prepareForDraw();
+        }
+        if (fCanDiscardCanvasContents) {
+            if (NULL != fSurface) {
+                // Pre-empt notifyContentChanged(false) calls that will happen
+                // during flush
+                fSurface->notifyContentWillChange(SkSurface::kDiscard_ContentChangeMode);
+            }
+            fCanDiscardCanvasContents = false;
+        }
     }
     fPipeWriter.flushRecording(true);
     fPipeController.playback(kSilent_PlaybackMode == playbackMode);