cc/paint/paint_op_buffer_serializer.cc - chromium/src - Git at Google

 // Copyright 2017 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "cc/paint/paint_op_buffer_serializer.h"

 #include <limits>
 #include <memory>
 #include <utility>
 #include <vector>

 #include "base/bind.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/paint/clear_for_opaque_raster.h"
 #include "cc/paint/paint_op_buffer_iterator.h"
 #include "cc/paint/scoped_raster_flags.h"
 #include "skia/ext/legacy_display_globals.h"
 #include "third_party/skia/include/core/SkColorSpace.h"
 #include "ui/gfx/geometry/skia_conversions.h"

 namespace cc {
 namespace {

 PlaybackParams MakeParams(const SkCanvas* canvas) {
   // We don't use an ImageProvider here since the ops are played onto a no-draw
   // canvas for state tracking and don't need decoded images.
   PlaybackParams params(nullptr, canvas->getLocalToDevice());
   params.is_analyzing = true;
   return params;
 }

 std::unique_ptr<SkCanvas> MakeAnalysisCanvas(
     const PaintOp::SerializeOptions& options) {
   // Use half of the max int as the extent for the SkNoDrawCanvas. The correct
   // clip is applied to the canvas during serialization.
   const int kMaxExtent = std::numeric_limits<int>::max() >> 1;

   return options.strike_server
              ? options.strike_server->makeAnalysisCanvas(
                    kMaxExtent, kMaxExtent,
                    skia::LegacyDisplayGlobals::ComputeSurfaceProps(
                        options.can_use_lcd_text),
                    options.color_space,
                    options.context_supports_distance_field_text)
              : std::make_unique<SkNoDrawCanvas>(kMaxExtent, kMaxExtent);
 }

 }  // namespace

 PaintOpBufferSerializer::PaintOpBufferSerializer(
     SerializeCallback serialize_cb,
     const PaintOp::SerializeOptions& options)
     : serialize_cb_(std::move(serialize_cb)), options_(options) {
   DCHECK(serialize_cb_);
 }

 PaintOpBufferSerializer::~PaintOpBufferSerializer() = default;

 void PaintOpBufferSerializer::Serialize(const PaintOpBuffer& buffer,
                                         const std::vector<size_t>* offsets,
                                         const Preamble& preamble) {
   std::unique_ptr<SkCanvas> canvas = MakeAnalysisCanvas(options_);

   // These PlaybackParams use the initial (identity) canvas matrix, as they are
   // only used for serializing the preamble and the initial save / final restore
   // SerializeBuffer will create its own PlaybackParams based on the
   // post-preamble canvas.
   PlaybackParams params = MakeParams(canvas.get());

   int saveCount = canvas->getSaveCount();
   Save(canvas.get(), params);
   SerializePreamble(canvas.get(), preamble, params);
   SerializeBuffer(canvas.get(), buffer, offsets);
   RestoreToCount(canvas.get(), saveCount, params);
 }

 void PaintOpBufferSerializer::Serialize(const PaintOpBuffer& buffer) {
   std::unique_ptr<SkCanvas> canvas = MakeAnalysisCanvas(options_);
   SerializeBuffer(canvas.get(), buffer, nullptr);
 }

 void PaintOpBufferSerializer::Serialize(const PaintOpBuffer& buffer,
                                         const gfx::Rect& playback_rect,
                                         const gfx::SizeF& post_scale) {
   std::unique_ptr<SkCanvas> canvas = MakeAnalysisCanvas(options_);

   PlaybackParams params = MakeParams(canvas.get());

   // TODO(khushalsagar): remove this clip rect if it's not needed.
   if (!playback_rect.IsEmpty()) {
     ClipRectOp clip_op(gfx::RectToSkRect(playback_rect), SkClipOp::kIntersect,
                        false);
     SerializeOp(canvas.get(), clip_op, nullptr, params);
   }

   if (post_scale.width() != 1.f || post_scale.height() != 1.f) {
     ScaleOp scale_op(post_scale.width(), post_scale.height());
     SerializeOp(canvas.get(), scale_op, nullptr, params);
   }

   SerializeBuffer(canvas.get(), buffer, nullptr);
 }

 // This function needs to have the exact same behavior as
 // RasterSource::ClearForOpaqueRaster.
 void PaintOpBufferSerializer::ClearForOpaqueRaster(
     SkCanvas* canvas,
     const Preamble& preamble,
     const PlaybackParams& params) {
   gfx::Rect outer_rect;
   gfx::Rect inner_rect;
   if (!CalculateClearForOpaqueRasterRects(
           preamble.post_translation, preamble.post_scale, preamble.content_size,
           preamble.full_raster_rect, preamble.playback_rect, outer_rect,
           inner_rect))
     return;

   Save(canvas, params);
   ClipRectOp outer_clip_op(gfx::RectToSkRect(outer_rect), SkClipOp::kIntersect,
                            false);
   SerializeOp(canvas, outer_clip_op, nullptr, params);
   if (!inner_rect.IsEmpty()) {
     ClipRectOp inner_clip_op(gfx::RectToSkRect(inner_rect),
                              SkClipOp::kDifference, false);
     SerializeOp(canvas, inner_clip_op, nullptr, params);
   }
   DrawColorOp clear_op(preamble.background_color, SkBlendMode::kSrc);
   SerializeOp(canvas, clear_op, nullptr, params);
   RestoreToCount(canvas, 1, params);
 }

 void PaintOpBufferSerializer::SerializePreamble(SkCanvas* canvas,
                                                 const Preamble& preamble,
                                                 const PlaybackParams& params) {
   DCHECK(preamble.full_raster_rect.Contains(preamble.playback_rect))
       << "full: " << preamble.full_raster_rect.ToString()
       << ", playback: " << preamble.playback_rect.ToString();

   // NOTE: The following code should be kept consistent with
   // RasterSource::PlaybackToCanvas().
   bool is_partial_raster = preamble.full_raster_rect != preamble.playback_rect;
   if (!preamble.requires_clear) {
     ClearForOpaqueRaster(canvas, preamble, params);
   } else if (!is_partial_raster) {
     // If rastering the entire tile, clear to transparent pre-clip.  This is so
     // that any external texels outside of the playback rect also get cleared.
     // There's not enough information at this point to know if this texture is
     // being reused from another tile, so the external texels could have been
     // cleared to some wrong value.
     DrawColorOp clear(SkColors::kTransparent, SkBlendMode::kSrc);
     SerializeOp(canvas, clear, nullptr, params);
   }

   if (!preamble.full_raster_rect.OffsetFromOrigin().IsZero()) {
     TranslateOp translate_op(-preamble.full_raster_rect.x(),
                              -preamble.full_raster_rect.y());
     SerializeOp(canvas, translate_op, nullptr, params);
   }

   if (!preamble.playback_rect.IsEmpty()) {
     ClipRectOp clip_op(gfx::RectToSkRect(preamble.playback_rect),
                        SkClipOp::kIntersect, false);
     SerializeOp(canvas, clip_op, nullptr, params);
   }

   if (!preamble.post_translation.IsZero()) {
     TranslateOp translate_op(preamble.post_translation.x(),
                              preamble.post_translation.y());
     SerializeOp(canvas, translate_op, nullptr, params);
   }

   if (preamble.post_scale.x() != 1.f || preamble.post_scale.y() != 1.f) {
     ScaleOp scale_op(preamble.post_scale.x(), preamble.post_scale.y());
     SerializeOp(canvas, scale_op, nullptr, params);
   }

   // If tile is transparent and this is partial raster, just clear the
   // section that is being rastered.  If this is opaque, trust the raster
   // to write all the pixels inside of the full_raster_rect.
   if (preamble.requires_clear && is_partial_raster) {
     DrawColorOp clear_op(SkColors::kTransparent, SkBlendMode::kSrc);
     SerializeOp(canvas, clear_op, nullptr, params);
   }
 }

 bool PaintOpBufferSerializer::WillSerializeNextOp(const PaintOp& op,
                                                   SkCanvas* canvas,
                                                   const PlaybackParams& params,
                                                   uint8_t alpha) {
   // Skip ops outside the current clip if they have images. This saves
   // performing an unnecessary expensive decode.
   bool skip_op = PaintOp::OpHasDiscardableImages(op) &&
                  PaintOp::QuickRejectDraw(op, canvas);
   // Skip text ops if there is no SkStrikeServer.
   skip_op |=
       op.GetType() == PaintOpType::DrawTextBlob && !options_.strike_server;
   if (skip_op)
     return true;

   if (op.GetType() == PaintOpType::DrawRecord) {
     int save_count = canvas->getSaveCount();
     Save(canvas, params);
     SerializeBuffer(
         canvas, static_cast<const DrawRecordOp&>(op).record.buffer(), nullptr);
     RestoreToCount(canvas, save_count, params);
     return true;
   }

   if (op.GetType() == PaintOpType::DrawImageRect &&
       static_cast<const DrawImageRectOp&>(op).image.IsPaintWorklet()) {
     DCHECK(options_.image_provider);
     const DrawImageRectOp& draw_op = static_cast<const DrawImageRectOp&>(op);
     ImageProvider::ScopedResult result =
         options_.image_provider->GetRasterContent(DrawImage(draw_op.image));
     if (!result || !result.paint_record())
       return true;

     int save_count = canvas->getSaveCount();
     Save(canvas, params);
     // The following ops are copying the canvas's ops from
     // DrawImageRectOp::RasterWithFlags.
     SkM44 trans = SkM44(SkMatrix::RectToRect(draw_op.src, draw_op.dst));
     ConcatOp concat_op(trans);
     bool success = SerializeOp(canvas, concat_op, nullptr, params);

     if (!success)
       return false;

     ClipRectOp clip_rect_op(draw_op.src, SkClipOp::kIntersect, false);
     success = SerializeOp(canvas, clip_rect_op, nullptr, params);
     if (!success)
       return false;

     // In DrawImageRectOp::RasterWithFlags, the save layer uses the
     // flags_to_serialize or default(null) flags. At this point in the
     // serialization, flags_to_serialize is always null as well.
     SaveLayerOp save_layer_op(&draw_op.src, nullptr);
     success = SerializeOpWithFlags(canvas, save_layer_op, params, 255);
     if (!success)
       return false;

     SerializeBuffer(canvas, result.paint_record()->buffer(), nullptr);
     RestoreToCount(canvas, save_count, params);
     return true;
   } else {
     if (op.IsPaintOpWithFlags()) {
       return SerializeOpWithFlags(
           canvas, static_cast<const PaintOpWithFlags&>(op), params, alpha);
     } else {
       return SerializeOp(canvas, op, nullptr, params);
     }
   }
 }

 void PaintOpBufferSerializer::SerializeBuffer(
     SkCanvas* canvas,
     const PaintOpBuffer& buffer,
     const std::vector<size_t>* offsets) {
   // This updates the original_ctm to reflect the canvas transformation at
   // start of this call to SerializeBuffer.
   PlaybackParams params = MakeParams(canvas);

   for (PaintOpBuffer::PlaybackFoldingIterator iter(buffer, offsets); iter;
        ++iter) {
     const PaintOp& op = *iter;
     if (!WillSerializeNextOp(op, canvas, params, iter.alpha())) {
       return;
     }
   }
 }

 bool PaintOpBufferSerializer::SerializeOpWithFlags(
     SkCanvas* canvas,
     const PaintOpWithFlags& flags_op,
     const PlaybackParams& params,
     uint8_t alpha) {
   // We use a null |image_provider| here because images are decoded during
   // serialization.
   const ScopedRasterFlags scoped_flags(
       &flags_op.flags, nullptr, canvas->getTotalMatrix(),
       options_.max_texture_size, alpha / 255.0f);
   const PaintFlags* flags_to_serialize = scoped_flags.flags();
   if (!flags_to_serialize)
     return true;

   return SerializeOp(canvas, flags_op, flags_to_serialize, params);
 }

 bool PaintOpBufferSerializer::SerializeOp(SkCanvas* canvas,
                                           const PaintOp& op,
                                           const PaintFlags* flags_to_serialize,
                                           const PlaybackParams& params) {
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
                "PaintOpBufferSerializer::SerializeOp", "op",
                PaintOpTypeToString(op.GetType()));
   if (!valid_)
     return false;

   // Playback on analysis canvas first to make sure the canvas transform is set
   // correctly for analysis of records in filters.
   PlaybackOnAnalysisCanvas(canvas, op, flags_to_serialize, params);

   size_t bytes =
       serialize_cb_.Run(op, options_, flags_to_serialize,
                         canvas->getLocalToDevice(), params.original_ctm);
   if (!bytes) {
     valid_ = false;
     return false;
   }

   DCHECK_GE(bytes, 4u);
   DCHECK_EQ(bytes % PaintOpBuffer::kPaintOpAlign, 0u);
   return true;
 }

 void PaintOpBufferSerializer::PlaybackOnAnalysisCanvas(
     SkCanvas* canvas,
     const PaintOp& op,
     const PaintFlags* flags_to_serialize,
     const PlaybackParams& params) {
   // Only 2 types of ops need to played on the analysis canvas.
   // 1) Non-draw ops which affect the transform/clip state on the canvas, since
   //    we need the correct ctm at which text and images will be rasterized, and
   //    the clip rect so we can skip sending data for ops which will not be
   //    rasterized.
   // 2) DrawTextBlob ops since they need to be analyzed by the cache diff canvas
   //    to serialize/lock the requisite glyphs for this op.
   if (op.IsDrawOp() && op.GetType() != PaintOpType::DrawTextBlob)
     return;

   if (op.IsPaintOpWithFlags() && flags_to_serialize) {
     static_cast<const PaintOpWithFlags&>(op).RasterWithFlags(
         canvas, flags_to_serialize, params);
   } else {
     op.Raster(canvas, params);
   }
 }

 void PaintOpBufferSerializer::Save(SkCanvas* canvas,
                                    const PlaybackParams& params) {
   SaveOp save_op;
   SerializeOp(canvas, save_op, nullptr, params);
 }

 void PaintOpBufferSerializer::RestoreToCount(SkCanvas* canvas,
                                              int count,
                                              const PlaybackParams& params) {
   RestoreOp restore_op;
   while (canvas->getSaveCount() > count) {
     if (!SerializeOp(canvas, restore_op, nullptr, params))
       return;
   }
 }

 SimpleBufferSerializer::SimpleBufferSerializer(
     void* memory,
     size_t size,
     const PaintOp::SerializeOptions& options)
     : PaintOpBufferSerializer(
           base::BindRepeating(&SimpleBufferSerializer::SerializeToMemory,
                               base::Unretained(this)),
           options),
       memory_(memory),
       total_(size) {}

 SimpleBufferSerializer::~SimpleBufferSerializer() = default;

 size_t SimpleBufferSerializer::SerializeToMemory(
     const PaintOp& op,
     const PaintOp::SerializeOptions& options,
     const PaintFlags* flags_to_serialize,
     const SkM44& current_ctm,
     const SkM44& original_ctm) {
   if (written_ == total_)
     return 0u;

   size_t bytes =
       op.Serialize(static_cast<char*>(memory_) + written_, total_ - written_,
                    options, flags_to_serialize, current_ctm, original_ctm);
   if (!bytes)
     return 0u;

   written_ += bytes;
   DCHECK_GE(total_, written_);
   return bytes;
 }

 }  // namespace cc
	// Copyright 2017 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "cc/paint/paint_op_buffer_serializer.h"

	#include <limits>
	#include <memory>
	#include <utility>
	#include <vector>

	#include "base/bind.h"
	#include "base/trace_event/trace_event.h"
	#include "cc/paint/clear_for_opaque_raster.h"
	#include "cc/paint/paint_op_buffer_iterator.h"
	#include "cc/paint/scoped_raster_flags.h"
	#include "skia/ext/legacy_display_globals.h"
	#include "third_party/skia/include/core/SkColorSpace.h"
	#include "ui/gfx/geometry/skia_conversions.h"

	namespace cc {
	namespace {

	PlaybackParams MakeParams(const SkCanvas* canvas) {
	// We don't use an ImageProvider here since the ops are played onto a no-draw
	// canvas for state tracking and don't need decoded images.
	PlaybackParams params(nullptr, canvas->getLocalToDevice());
	params.is_analyzing = true;
	return params;
	}

	std::unique_ptr<SkCanvas> MakeAnalysisCanvas(
	const PaintOp::SerializeOptions& options) {
	// Use half of the max int as the extent for the SkNoDrawCanvas. The correct
	// clip is applied to the canvas during serialization.
	const int kMaxExtent = std::numeric_limits<int>::max() >> 1;

	return options.strike_server
	? options.strike_server->makeAnalysisCanvas(
	kMaxExtent, kMaxExtent,
	skia::LegacyDisplayGlobals::ComputeSurfaceProps(
	options.can_use_lcd_text),
	options.color_space,
	options.context_supports_distance_field_text)
	: std::make_unique<SkNoDrawCanvas>(kMaxExtent, kMaxExtent);
	}

	} // namespace

	PaintOpBufferSerializer::PaintOpBufferSerializer(
	SerializeCallback serialize_cb,
	const PaintOp::SerializeOptions& options)
	: serialize_cb_(std::move(serialize_cb)), options_(options) {
	DCHECK(serialize_cb_);
	}

	PaintOpBufferSerializer::~PaintOpBufferSerializer() = default;

	void PaintOpBufferSerializer::Serialize(const PaintOpBuffer& buffer,
	const std::vector<size_t>* offsets,
	const Preamble& preamble) {
	std::unique_ptr<SkCanvas> canvas = MakeAnalysisCanvas(options_);

	// These PlaybackParams use the initial (identity) canvas matrix, as they are
	// only used for serializing the preamble and the initial save / final restore
	// SerializeBuffer will create its own PlaybackParams based on the
	// post-preamble canvas.
	PlaybackParams params = MakeParams(canvas.get());

	int saveCount = canvas->getSaveCount();
	Save(canvas.get(), params);
	SerializePreamble(canvas.get(), preamble, params);
	SerializeBuffer(canvas.get(), buffer, offsets);
	RestoreToCount(canvas.get(), saveCount, params);
	}

	void PaintOpBufferSerializer::Serialize(const PaintOpBuffer& buffer) {
	std::unique_ptr<SkCanvas> canvas = MakeAnalysisCanvas(options_);
	SerializeBuffer(canvas.get(), buffer, nullptr);
	}

	void PaintOpBufferSerializer::Serialize(const PaintOpBuffer& buffer,
	const gfx::Rect& playback_rect,
	const gfx::SizeF& post_scale) {
	std::unique_ptr<SkCanvas> canvas = MakeAnalysisCanvas(options_);

	PlaybackParams params = MakeParams(canvas.get());

	// TODO(khushalsagar): remove this clip rect if it's not needed.
	if (!playback_rect.IsEmpty()) {
	ClipRectOp clip_op(gfx::RectToSkRect(playback_rect), SkClipOp::kIntersect,
	false);
	SerializeOp(canvas.get(), clip_op, nullptr, params);
	}

	if (post_scale.width() != 1.f \|\| post_scale.height() != 1.f) {
	ScaleOp scale_op(post_scale.width(), post_scale.height());
	SerializeOp(canvas.get(), scale_op, nullptr, params);
	}

	SerializeBuffer(canvas.get(), buffer, nullptr);
	}

	// This function needs to have the exact same behavior as
	// RasterSource::ClearForOpaqueRaster.
	void PaintOpBufferSerializer::ClearForOpaqueRaster(
	SkCanvas* canvas,
	const Preamble& preamble,
	const PlaybackParams& params) {
	gfx::Rect outer_rect;
	gfx::Rect inner_rect;
	if (!CalculateClearForOpaqueRasterRects(
	preamble.post_translation, preamble.post_scale, preamble.content_size,
	preamble.full_raster_rect, preamble.playback_rect, outer_rect,
	inner_rect))
	return;

	Save(canvas, params);
	ClipRectOp outer_clip_op(gfx::RectToSkRect(outer_rect), SkClipOp::kIntersect,
	false);
	SerializeOp(canvas, outer_clip_op, nullptr, params);
	if (!inner_rect.IsEmpty()) {
	ClipRectOp inner_clip_op(gfx::RectToSkRect(inner_rect),
	SkClipOp::kDifference, false);
	SerializeOp(canvas, inner_clip_op, nullptr, params);
	}
	DrawColorOp clear_op(preamble.background_color, SkBlendMode::kSrc);
	SerializeOp(canvas, clear_op, nullptr, params);
	RestoreToCount(canvas, 1, params);
	}

	void PaintOpBufferSerializer::SerializePreamble(SkCanvas* canvas,
	const Preamble& preamble,
	const PlaybackParams& params) {
	DCHECK(preamble.full_raster_rect.Contains(preamble.playback_rect))
	<< "full: " << preamble.full_raster_rect.ToString()
	<< ", playback: " << preamble.playback_rect.ToString();

	// NOTE: The following code should be kept consistent with
	// RasterSource::PlaybackToCanvas().
	bool is_partial_raster = preamble.full_raster_rect != preamble.playback_rect;
	if (!preamble.requires_clear) {
	ClearForOpaqueRaster(canvas, preamble, params);
	} else if (!is_partial_raster) {
	// If rastering the entire tile, clear to transparent pre-clip. This is so
	// that any external texels outside of the playback rect also get cleared.
	// There's not enough information at this point to know if this texture is
	// being reused from another tile, so the external texels could have been
	// cleared to some wrong value.
	DrawColorOp clear(SkColors::kTransparent, SkBlendMode::kSrc);
	SerializeOp(canvas, clear, nullptr, params);
	}

	if (!preamble.full_raster_rect.OffsetFromOrigin().IsZero()) {
	TranslateOp translate_op(-preamble.full_raster_rect.x(),
	-preamble.full_raster_rect.y());
	SerializeOp(canvas, translate_op, nullptr, params);
	}

	if (!preamble.playback_rect.IsEmpty()) {
	ClipRectOp clip_op(gfx::RectToSkRect(preamble.playback_rect),
	SkClipOp::kIntersect, false);
	SerializeOp(canvas, clip_op, nullptr, params);
	}

	if (!preamble.post_translation.IsZero()) {
	TranslateOp translate_op(preamble.post_translation.x(),
	preamble.post_translation.y());
	SerializeOp(canvas, translate_op, nullptr, params);
	}

	if (preamble.post_scale.x() != 1.f \|\| preamble.post_scale.y() != 1.f) {
	ScaleOp scale_op(preamble.post_scale.x(), preamble.post_scale.y());
	SerializeOp(canvas, scale_op, nullptr, params);
	}

	// If tile is transparent and this is partial raster, just clear the
	// section that is being rastered. If this is opaque, trust the raster
	// to write all the pixels inside of the full_raster_rect.
	if (preamble.requires_clear && is_partial_raster) {
	DrawColorOp clear_op(SkColors::kTransparent, SkBlendMode::kSrc);
	SerializeOp(canvas, clear_op, nullptr, params);
	}
	}

	bool PaintOpBufferSerializer::WillSerializeNextOp(const PaintOp& op,
	SkCanvas* canvas,
	const PlaybackParams& params,
	uint8_t alpha) {
	// Skip ops outside the current clip if they have images. This saves
	// performing an unnecessary expensive decode.
	bool skip_op = PaintOp::OpHasDiscardableImages(op) &&
	PaintOp::QuickRejectDraw(op, canvas);
	// Skip text ops if there is no SkStrikeServer.
	skip_op \|=
	op.GetType() == PaintOpType::DrawTextBlob && !options_.strike_server;
	if (skip_op)
	return true;

	if (op.GetType() == PaintOpType::DrawRecord) {
	int save_count = canvas->getSaveCount();
	Save(canvas, params);
	SerializeBuffer(
	canvas, static_cast<const DrawRecordOp&>(op).record.buffer(), nullptr);
	RestoreToCount(canvas, save_count, params);
	return true;
	}

	if (op.GetType() == PaintOpType::DrawImageRect &&
	static_cast<const DrawImageRectOp&>(op).image.IsPaintWorklet()) {
	DCHECK(options_.image_provider);
	const DrawImageRectOp& draw_op = static_cast<const DrawImageRectOp&>(op);
	ImageProvider::ScopedResult result =
	options_.image_provider->GetRasterContent(DrawImage(draw_op.image));
	if (!result \|\| !result.paint_record())
	return true;

	int save_count = canvas->getSaveCount();
	Save(canvas, params);
	// The following ops are copying the canvas's ops from
	// DrawImageRectOp::RasterWithFlags.
	SkM44 trans = SkM44(SkMatrix::RectToRect(draw_op.src, draw_op.dst));
	ConcatOp concat_op(trans);
	bool success = SerializeOp(canvas, concat_op, nullptr, params);

	if (!success)
	return false;

	ClipRectOp clip_rect_op(draw_op.src, SkClipOp::kIntersect, false);
	success = SerializeOp(canvas, clip_rect_op, nullptr, params);
	if (!success)
	return false;

	// In DrawImageRectOp::RasterWithFlags, the save layer uses the
	// flags_to_serialize or default(null) flags. At this point in the
	// serialization, flags_to_serialize is always null as well.
	SaveLayerOp save_layer_op(&draw_op.src, nullptr);
	success = SerializeOpWithFlags(canvas, save_layer_op, params, 255);
	if (!success)
	return false;

	SerializeBuffer(canvas, result.paint_record()->buffer(), nullptr);
	RestoreToCount(canvas, save_count, params);
	return true;
	} else {
	if (op.IsPaintOpWithFlags()) {
	return SerializeOpWithFlags(
	canvas, static_cast<const PaintOpWithFlags&>(op), params, alpha);
	} else {
	return SerializeOp(canvas, op, nullptr, params);
	}
	}
	}

	void PaintOpBufferSerializer::SerializeBuffer(
	SkCanvas* canvas,
	const PaintOpBuffer& buffer,
	const std::vector<size_t>* offsets) {
	// This updates the original_ctm to reflect the canvas transformation at
	// start of this call to SerializeBuffer.
	PlaybackParams params = MakeParams(canvas);

	for (PaintOpBuffer::PlaybackFoldingIterator iter(buffer, offsets); iter;
	++iter) {
	const PaintOp& op = *iter;
	if (!WillSerializeNextOp(op, canvas, params, iter.alpha())) {
	return;
	}
	}
	}

	bool PaintOpBufferSerializer::SerializeOpWithFlags(
	SkCanvas* canvas,
	const PaintOpWithFlags& flags_op,
	const PlaybackParams& params,
	uint8_t alpha) {
	// We use a null \|image_provider\| here because images are decoded during
	// serialization.
	const ScopedRasterFlags scoped_flags(
	&flags_op.flags, nullptr, canvas->getTotalMatrix(),
	options_.max_texture_size, alpha / 255.0f);
	const PaintFlags* flags_to_serialize = scoped_flags.flags();
	if (!flags_to_serialize)
	return true;

	return SerializeOp(canvas, flags_op, flags_to_serialize, params);
	}

	bool PaintOpBufferSerializer::SerializeOp(SkCanvas* canvas,
	const PaintOp& op,
	const PaintFlags* flags_to_serialize,
	const PlaybackParams& params) {
	TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
	"PaintOpBufferSerializer::SerializeOp", "op",
	PaintOpTypeToString(op.GetType()));
	if (!valid_)
	return false;

	// Playback on analysis canvas first to make sure the canvas transform is set
	// correctly for analysis of records in filters.
	PlaybackOnAnalysisCanvas(canvas, op, flags_to_serialize, params);

	size_t bytes =
	serialize_cb_.Run(op, options_, flags_to_serialize,
	canvas->getLocalToDevice(), params.original_ctm);
	if (!bytes) {
	valid_ = false;
	return false;
	}

	DCHECK_GE(bytes, 4u);
	DCHECK_EQ(bytes % PaintOpBuffer::kPaintOpAlign, 0u);
	return true;
	}

	void PaintOpBufferSerializer::PlaybackOnAnalysisCanvas(
	SkCanvas* canvas,
	const PaintOp& op,
	const PaintFlags* flags_to_serialize,
	const PlaybackParams& params) {
	// Only 2 types of ops need to played on the analysis canvas.
	// 1) Non-draw ops which affect the transform/clip state on the canvas, since
	// we need the correct ctm at which text and images will be rasterized, and
	// the clip rect so we can skip sending data for ops which will not be
	// rasterized.
	// 2) DrawTextBlob ops since they need to be analyzed by the cache diff canvas
	// to serialize/lock the requisite glyphs for this op.
	if (op.IsDrawOp() && op.GetType() != PaintOpType::DrawTextBlob)
	return;

	if (op.IsPaintOpWithFlags() && flags_to_serialize) {
	static_cast<const PaintOpWithFlags&>(op).RasterWithFlags(
	canvas, flags_to_serialize, params);
	} else {
	op.Raster(canvas, params);
	}
	}

	void PaintOpBufferSerializer::Save(SkCanvas* canvas,
	const PlaybackParams& params) {
	SaveOp save_op;
	SerializeOp(canvas, save_op, nullptr, params);
	}

	void PaintOpBufferSerializer::RestoreToCount(SkCanvas* canvas,
	int count,
	const PlaybackParams& params) {
	RestoreOp restore_op;
	while (canvas->getSaveCount() > count) {
	if (!SerializeOp(canvas, restore_op, nullptr, params))
	return;
	}
	}

	SimpleBufferSerializer::SimpleBufferSerializer(
	void* memory,
	size_t size,
	const PaintOp::SerializeOptions& options)
	: PaintOpBufferSerializer(
	base::BindRepeating(&SimpleBufferSerializer::SerializeToMemory,
	base::Unretained(this)),
	options),
	memory_(memory),
	total_(size) {}

	SimpleBufferSerializer::~SimpleBufferSerializer() = default;

	size_t SimpleBufferSerializer::SerializeToMemory(
	const PaintOp& op,
	const PaintOp::SerializeOptions& options,
	const PaintFlags* flags_to_serialize,
	const SkM44& current_ctm,
	const SkM44& original_ctm) {
	if (written_ == total_)
	return 0u;

	size_t bytes =
	op.Serialize(static_cast<char*>(memory_) + written_, total_ - written_,
	options, flags_to_serialize, current_ctm, original_ctm);
	if (!bytes)
	return 0u;

	written_ += bytes;
	DCHECK_GE(total_, written_);
	return bytes;
	}

	} // namespace cc