Abort canvas analysis after a few operations are rejected

skia/ext/analysis_canvas.cc

 // Copyright (c) 2013 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 "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "skia/ext/analysis_canvas.h"
 #include "third_party/skia/include/core/SkDraw.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkRRect.h"
@@ skipping 36 matching lines @@
 
 // Returns true if the specified drawn_rect will cover the entire canvas, and
 // that the canvas is not clipped (i.e. it covers ALL of the canvas).
 bool IsFullQuad(SkCanvas* canvas, const SkRect& drawn_rect) {
   if (!canvas->isClipRect())
     return false;
 
   SkIRect clip_irect;
   if (!canvas->getClipDeviceBounds(&clip_irect))
     return false;
-  
+
   // if the clip is smaller than the canvas, we're partly clipped, so abort.
   if (!clip_irect.contains(SkIRect::MakeSize(canvas->getBaseLayerSize())))
     return false;
 
   const SkMatrix& matrix = canvas->getTotalMatrix();
   // If the transform results in a non-axis aligned
   // rect, then be conservative and return false.
   if (!matrix.rectStaysRect())
     return false;
 
@@ skipping 38 matching lines @@
 }
 
 void AnalysisCanvas::onDrawRect(const SkRect& rect, const SkPaint& paint) {
   TRACE_EVENT0("disabled-by-default-skia", "AnalysisCanvas::onDrawRect");
   // This recreates the early-exit logic in SkCanvas.cpp.
   SkRect scratch;
   if (paint.canComputeFastBounds() &&
       quickReject(paint.computeFastBounds(rect, &scratch))) {
     TRACE_EVENT_INSTANT0("disabled-by-default-skia", "Quick reject.",
                          TRACE_EVENT_SCOPE_THREAD);
+    ++rejected_op_count_;
     return;
   }
 
   // An extra no-op check SkCanvas.cpp doesn't do.
   if (paint.nothingToDraw()) {
     TRACE_EVENT_INSTANT0("disabled-by-default-skia", "Nothing to draw.",
                          TRACE_EVENT_SCOPE_THREAD);
     return;
   }
 
@@ skipping 216 matching lines @@
 AnalysisCanvas::AnalysisCanvas(int width, int height)
     : INHERITED(MakeEmptyBitmap(width, height)),
       saved_stack_size_(0),
       force_not_solid_stack_level_(kNoLayer),
       force_not_transparent_stack_level_(kNoLayer),
       is_forced_not_solid_(false),
       is_forced_not_transparent_(false),
       is_solid_color_(true),
       color_(SK_ColorTRANSPARENT),
       is_transparent_(true),
-      draw_op_count_(0) {
+      draw_op_count_(0),
+      rejected_op_count_(0) {
 }
 
 AnalysisCanvas::~AnalysisCanvas() {}
 
 bool AnalysisCanvas::GetColorIfSolid(SkColor* color) const {
   if (is_transparent_) {
     *color = SK_ColorTRANSPARENT;
     return true;
   }
   if (is_solid_color_) {
     *color = color_;
     return true;
   }
   return false;
 }
 
 bool AnalysisCanvas::abort() {
-  // Early out as soon as we have more than one draw op.
-  // TODO(vmpstr): Investigate if 1 is the correct metric here. We need to
-  // balance the amount of time we spend analyzing vs how many tiles would be
-  // solid if the number was higher.
-  if (draw_op_count_ > 1) {
+  // Early out as soon as we have more than 1 draw op or 5 rejected ops.
+  // TODO(vmpstr): Investigate if 1 and 5 are the correct metrics here. We need
+  // to balance the amount of time we spend analyzing vs how many tiles would be
+  // solid if the numbers were higher.
+  if (draw_op_count_ > 1 || rejected_op_count_ > 5) {
     TRACE_EVENT0("disabled-by-default-skia",
                  "AnalysisCanvas::abort() -- aborting");
     // We have to reset solid/transparent state to false since we don't
     // know whether consequent operations will make this false.
     is_solid_color_ = false;
     is_transparent_ = false;
     return true;
   }
   return false;
 }
@@ skipping 101 matching lines @@
       force_not_transparent_stack_level_ = kNoLayer;
     }
   }
 
   INHERITED::willRestore();
 }
 
 }  // namespace skia