Raster display item lists via a visual rect RTree.

cc/playback/display_item_list.cc

 // 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 "cc/playback/display_item_list.h"
 
 #include <stddef.h>
 
 #include <string>
 
 #include "base/numerics/safe_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/base/math_util.h"
 #include "cc/debug/picture_debug_util.h"
 #include "cc/debug/traced_display_item_list.h"
 #include "cc/debug/traced_value.h"
 #include "cc/playback/display_item_list_settings.h"
 #include "cc/playback/display_item_proto_factory.h"
 #include "cc/playback/drawing_display_item.h"
 #include "cc/playback/largest_display_item.h"
 #include "cc/proto/display_item.pb.h"
 #include "cc/proto/gfx_conversions.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/utils/SkPictureUtils.h"
 #include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
 namespace {
 
 // We don't perform per-layer solid color analysis when there are too many skia
 // operations.
 const int kOpCountThatIsOkToAnalyze = 10;
 
 bool DisplayItemsTracingEnabled() {
   bool tracing_enabled;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.display_items"), &tracing_enabled);
   return tracing_enabled;
 }
 
+bool GetCanvasClipBounds(SkCanvas* canvas, gfx::Rect* clip_bounds) {
+  SkRect canvas_clip_bounds;
+  if (!canvas->getClipBounds(&canvas_clip_bounds))
+    return false;
+  *clip_bounds = ToEnclosingRect(gfx::SkRectToRectF(canvas_clip_bounds));
+  return true;
+}
+
 const int kDefaultNumDisplayItemsToReserve = 100;
 
 }  // namespace
 
-DisplayItemList::Inputs::Inputs(gfx::Rect layer_rect,
-                                const DisplayItemListSettings& settings)
+DisplayItemList::Inputs::Inputs(const DisplayItemListSettings& settings)
     : items(LargestDisplayItemSize(),
             LargestDisplayItemSize() * kDefaultNumDisplayItemsToReserve),
-      settings(settings),
-      layer_rect(layer_rect),
-      is_suitable_for_gpu_rasterization(true) {}
+      settings(settings) {}
 
 DisplayItemList::Inputs::~Inputs() {}
 
 scoped_refptr<DisplayItemList> DisplayItemList::Create(
-    const gfx::Rect& layer_rect,
     const DisplayItemListSettings& settings) {
-  return make_scoped_refptr(new DisplayItemList(
-      layer_rect, settings,
-      !settings.use_cached_picture || DisplayItemsTracingEnabled()));
+  return make_scoped_refptr(new DisplayItemList(settings));
 }
 
 scoped_refptr<DisplayItemList> DisplayItemList::CreateFromProto(
     const proto::DisplayItemList& proto,
     ClientPictureCache* client_picture_cache,
     std::vector<uint32_t>* used_engine_picture_ids) {
-  gfx::Rect layer_rect = ProtoToRect(proto.layer_rect());
   scoped_refptr<DisplayItemList> list =
-      DisplayItemList::Create(ProtoToRect(proto.layer_rect()),
-                              DisplayItemListSettings(proto.settings()));
+      DisplayItemList::Create(DisplayItemListSettings(proto.settings()));
 
   for (int i = 0; i < proto.items_size(); i++) {
     const proto::DisplayItem& item_proto = proto.items(i);
+    const gfx::Rect visual_rect = ProtoToRect(proto.visual_rects(i));
     DisplayItemProtoFactory::AllocateAndConstruct(
-        layer_rect, list.get(), item_proto, client_picture_cache,
+        visual_rect, list.get(), item_proto, client_picture_cache,
         used_engine_picture_ids);
   }
 
   list->Finalize();
 
   return list;
 }
 
-DisplayItemList::DisplayItemList(gfx::Rect layer_rect,
-                                 const DisplayItemListSettings& settings,
-                                 bool retain_individual_display_items)
-    : retain_individual_display_items_(retain_individual_display_items),
-      approximate_op_count_(0),
-      picture_memory_usage_(0),
-      inputs_(layer_rect, settings) {
-  if (inputs_.settings.use_cached_picture) {
-    SkRTreeFactory factory;
-    recorder_.reset(new SkPictureRecorder());
-
-    SkCanvas* canvas = recorder_->beginRecording(
-        inputs_.layer_rect.width(), inputs_.layer_rect.height(), &factory);
-    canvas->translate(-inputs_.layer_rect.x(), -inputs_.layer_rect.y());
-    canvas->clipRect(gfx::RectToSkRect(inputs_.layer_rect));
-  }
-}
+DisplayItemList::DisplayItemList(const DisplayItemListSettings& settings)
+    : inputs_(settings) {}
 
 DisplayItemList::~DisplayItemList() {
 }
 
 void DisplayItemList::ToProtobuf(proto::DisplayItemList* proto) {
   // The flattened SkPicture approach is going away, and the proto
   // doesn't currently support serializing that flattened picture.
-  DCHECK(retain_individual_display_items_);
-
-  RectToProto(inputs_.layer_rect, proto->mutable_layer_rect());
   inputs_.settings.ToProtobuf(proto->mutable_settings());
 
   DCHECK_EQ(0, proto->items_size());
-  for (const auto& item : inputs_.items)
+  DCHECK_EQ(0, proto->visual_rects_size());
+  DCHECK(inputs_.items.size() == inputs_.visual_rects.size())
+      << "items.size() " << inputs_.items.size() << " visual_rects.size() "
+      << inputs_.visual_rects.size();
+  int i = 0;
+  for (const auto& item : inputs_.items) {
+    RectToProto(inputs_.visual_rects[i++], proto->add_visual_rects());
     item.ToProtobuf(proto->add_items());
+  }
 }
 
 void DisplayItemList::Raster(SkCanvas* canvas,
                              SkPicture::AbortCallback* callback,
                              const gfx::Rect& canvas_target_playback_rect,
                              float contents_scale) const {
   canvas->save();
-
   if (!canvas_target_playback_rect.IsEmpty()) {
     // canvas_target_playback_rect is specified in device space. We can't
     // use clipRect because canvas CTM will be applied on it. Use clipRegion
     // instead because it ignores canvas CTM.
     SkRegion device_clip;
     device_clip.setRect(gfx::RectToSkIRect(canvas_target_playback_rect));
     canvas->clipRegion(device_clip);
   }
-
   canvas->scale(contents_scale, contents_scale);
   Raster(canvas, callback);
   canvas->restore();
 }
 
 void DisplayItemList::Raster(SkCanvas* canvas,
                              SkPicture::AbortCallback* callback) const {
-  if (!inputs_.settings.use_cached_picture) {
-    for (const auto& item : inputs_.items)
-      item.Raster(canvas, callback);
-  } else {
-    DCHECK(picture_);
+  gfx::Rect canvas_playback_rect;
+  if (!GetCanvasClipBounds(canvas, &canvas_playback_rect))
+    return;
 
-    canvas->save();
-    canvas->translate(inputs_.layer_rect.x(), inputs_.layer_rect.y());
-    if (callback) {
-      // If we have a callback, we need to call |draw()|, |drawPicture()|
-      // doesn't take a callback.  This is used by |AnalysisCanvas| to early
-      // out.
-      picture_->playback(canvas, callback);
-    } else {
-      // Prefer to call |drawPicture()| on the canvas since it could place the
-      // entire picture on the canvas instead of parsing the skia operations.
-      canvas->drawPicture(picture_.get());
-    }
-    canvas->restore();
+  std::vector<size_t> indices;
+  rtree_.Search(canvas_playback_rect, &indices);
+  for (size_t index : indices) {
+    inputs_.items[index].Raster(canvas, callback);
+    // We use a callback during solid color analysis on the compositor thread to
+    // break out early. Since we're handling a sequence of pictures via rtree
+    // query results ourselves, we have to respect the callback and early out.
+    if (callback && callback->abort())
+      break;
   }
 }
 
-void DisplayItemList::ProcessAppendedItem(const DisplayItem* item) {
-  if (inputs_.settings.use_cached_picture) {
-    DCHECK(recorder_);
-    item->Raster(recorder_->getRecordingCanvas(), nullptr);
-  }
-  if (!retain_individual_display_items_) {
-    inputs_.items.Clear();
-  }
-}
-
-void DisplayItemList::RasterIntoCanvas(const DisplayItem& item) {
-  DCHECK(recorder_);
-  DCHECK(!retain_individual_display_items_);
-
-  item.Raster(recorder_->getRecordingCanvas(), nullptr);
-}
-
-bool DisplayItemList::RetainsIndividualDisplayItems() const {
-  return retain_individual_display_items_;
-}
-
 void DisplayItemList::Finalize() {
   TRACE_EVENT0("cc", "DisplayItemList::Finalize");
-  // TODO(dtrainor): Need to deal with serializing visual_rects_.
+  // TODO(dtrainor): Need to deal with serializing inputs_.visual_rects.
   // http://crbug.com/568757.
-  DCHECK(!retain_individual_display_items_ ||
-         inputs_.items.size() == inputs_.visual_rects.size())
+  DCHECK(inputs_.items.size() == inputs_.visual_rects.size())
       << "items.size() " << inputs_.items.size() << " visual_rects.size() "
       << inputs_.visual_rects.size();
+  rtree_.Build(inputs_.visual_rects);
 
-  // TODO(vmpstr): Build and make use of an RTree from the visual
-  // rects. For now we just clear them out since we won't ever need
-  // them to stick around post-Finalize. http://crbug.com/527245
-  // This clears both the vector and the vector's capacity, since visual_rects_
-  // won't be used anymore.
-  std::vector<gfx::Rect>().swap(inputs_.visual_rects);
-
-  if (inputs_.settings.use_cached_picture) {
-    // Convert to an SkPicture for faster rasterization.
-    DCHECK(inputs_.settings.use_cached_picture);
-    DCHECK(!picture_);
-    picture_ = recorder_->finishRecordingAsPicture();
-    DCHECK(picture_);
-    picture_memory_usage_ =
-        SkPictureUtils::ApproximateBytesUsed(picture_.get());
-    recorder_.reset();
-  }
+  if (!retain_visual_rects_)
+    // This clears both the vector and the vector's capacity, since
+    // visual_rects won't be used anymore.
+    std::vector<gfx::Rect>().swap(inputs_.visual_rects);

[Khushal, 2016/08/02 23:47:54]

Looks like the visual rects are being dropped here and the
DisplayItemList::ToProtobuf which runs after Finalize is trying to serialize
them.

[wkorman, 2016/08/02 23:51:26]

Yes, possible, this is a memory optimization but perhaps it is not compatible
with Blimp's current control flow. If you comment this out, does it fix the
issue?

 }
 
 bool DisplayItemList::IsSuitableForGpuRasterization() const {
-  return inputs_.is_suitable_for_gpu_rasterization;
+  // TODO(wkorman): This is more permissive than Picture's implementation, since
+  // none of the items might individually trigger a veto even though they
+  // collectively have enough "bad" operations that a corresponding Picture
+  // would get vetoed. See crbug.com/513016.
+  return inputs_.all_items_are_suitable_for_gpu_rasterization;
 }
 
 int DisplayItemList::ApproximateOpCount() const {
-  if (retain_individual_display_items_)
-    return approximate_op_count_;
-  return picture_ ? picture_->approximateOpCount() : 0;
+  return approximate_op_count_;
 }
 
 size_t DisplayItemList::ApproximateMemoryUsage() const {
-  // We double-count in this case. Produce zero to avoid being misleading.
-  if (inputs_.settings.use_cached_picture && retain_individual_display_items_)
-    return 0;
-
-  DCHECK(!inputs_.settings.use_cached_picture || picture_);
-
   size_t memory_usage = sizeof(*this);
 
   size_t external_memory_usage = 0;
-  if (retain_individual_display_items_) {
-    // Warning: this double-counts SkPicture data if use_cached_picture is
-    // also true.
-    for (const auto& item : inputs_.items) {
-      external_memory_usage += item.ExternalMemoryUsage();
-    }
+  // Warning: this double-counts SkPicture data if use_cached_picture is
+  // also true.
+  for (const auto& item : inputs_.items) {
+    external_memory_usage += item.ExternalMemoryUsage();
   }
 
   // Memory outside this class due to |items_|.
   memory_usage += inputs_.items.GetCapacityInBytes() + external_memory_usage;
 
-  // Memory outside this class due to |picture|.
-  memory_usage += picture_memory_usage_;
-
   // TODO(jbroman): Does anything else owned by this class substantially
   // contribute to memory usage?
+  // TODO(vmpstr): Probably DiscardableImageMap is worth counting here.
 
   return memory_usage;
 }
 
 bool DisplayItemList::ShouldBeAnalyzedForSolidColor() const {
   return ApproximateOpCount() <= kOpCountThatIsOkToAnalyze;
 }
 
 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 DisplayItemList::AsValue(bool include_items) const {
   std::unique_ptr<base::trace_event::TracedValue> state(
       new base::trace_event::TracedValue());
 
   state->BeginDictionary("params");
   if (include_items) {
     state->BeginArray("items");
     size_t item_index = 0;
     for (const DisplayItem& item : inputs_.items) {
       item.AsValueInto(item_index < inputs_.visual_rects.size()
                            ? inputs_.visual_rects[item_index]
                            : gfx::Rect(),
                        state.get());
       item_index++;
     }
     state->EndArray();  // "items".
   }
-  state->SetValue("layer_rect", MathUtil::AsValue(inputs_.layer_rect));
   state->EndDictionary();  // "params".
 
-  if (!inputs_.layer_rect.IsEmpty()) {
-    SkPictureRecorder recorder;
-    SkCanvas* canvas = recorder.beginRecording(inputs_.layer_rect.width(),
-                                               inputs_.layer_rect.height());
-    canvas->translate(-inputs_.layer_rect.x(), -inputs_.layer_rect.y());
-    canvas->clipRect(gfx::RectToSkRect(inputs_.layer_rect));
-    Raster(canvas, NULL, gfx::Rect(), 1.f);
-    sk_sp<SkPicture> picture = recorder.finishRecordingAsPicture();
+  SkPictureRecorder recorder;
+  gfx::Rect bounds = rtree_.GetBounds();
+  SkCanvas* canvas = recorder.beginRecording(bounds.width(), bounds.height());
+  canvas->translate(-bounds.x(), -bounds.y());
+  canvas->clipRect(gfx::RectToSkRect(bounds));
+  Raster(canvas, nullptr, gfx::Rect(), 1.f);
+  sk_sp<SkPicture> picture = recorder.finishRecordingAsPicture();
 
-    std::string b64_picture;
-    PictureDebugUtil::SerializeAsBase64(picture.get(), &b64_picture);
-    state->SetString("skp64", b64_picture);
-  }
+  std::string b64_picture;
+  PictureDebugUtil::SerializeAsBase64(picture.get(), &b64_picture);
+  state->SetString("skp64", b64_picture);
 
   return std::move(state);
 }
 
 void DisplayItemList::EmitTraceSnapshot() const {
   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.display_items") ","
       TRACE_DISABLED_BY_DEFAULT("cc.debug.picture") ","
       TRACE_DISABLED_BY_DEFAULT("devtools.timeline.picture"),
       "cc::DisplayItemList", this,
       TracedDisplayItemList::AsTraceableDisplayItemList(this,
           DisplayItemsTracingEnabled()));
 }
 
 void DisplayItemList::GenerateDiscardableImagesMetadata() {
   // This should be only called once, and only after CreateAndCacheSkPicture.
   DCHECK(image_map_.empty());
-  DCHECK(!inputs_.settings.use_cached_picture || picture_);
-  if (inputs_.settings.use_cached_picture && !picture_->willPlayBackBitmaps())
-    return;
 
-  // The cached picture is translated by -layer_rect_.origin during record,
-  // so we need to offset that back in order to get right positioning for
-  // images.
+  gfx::Rect bounds = rtree_.GetBounds();
   DiscardableImageMap::ScopedMetadataGenerator generator(
-      &image_map_,
-      gfx::Size(inputs_.layer_rect.right(), inputs_.layer_rect.bottom()));
-  Raster(generator.canvas(), nullptr,
-         gfx::Rect(inputs_.layer_rect.right(), inputs_.layer_rect.bottom()),
-         1.f);
+      &image_map_, gfx::Size(bounds.right(), bounds.bottom()));
+  Raster(generator.canvas(), nullptr, gfx::Rect(), 1.f);
 }
 
 void DisplayItemList::GetDiscardableImagesInRect(
     const gfx::Rect& rect,
     float raster_scale,
     std::vector<DrawImage>* images) {
   image_map_.GetDiscardableImagesInRect(rect, raster_scale, images);
 }
 
 }  // namespace cc