dl_complexity.h

Go to the documentation of this file.

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#ifndef FLUTTER_DISPLAY_LIST_BENCHMARKING_DL_COMPLEXITY_H_
#define FLUTTER_DISPLAY_LIST_BENCHMARKING_DL_COMPLEXITY_H_
 
#include "flutter/display_list/display_list.h"
 
#include "third_party/skia/include/gpu/GrTypes.h"
 
namespace flutter {
 
class DisplayListComplexityCalculator {
 public:
  static DisplayListComplexityCalculator* GetForSoftware();
  static DisplayListComplexityCalculator* GetForBackend(GrBackendApi backend);
 
  virtual ~DisplayListComplexityCalculator() = default;
 
  // Returns a calculated complexity score for a given DisplayList object
  virtual unsigned int Compute(const DisplayList* display_list) = 0;
 
  // Returns whether a given complexity score meets the threshold for
  // cacheability for this particular ComplexityCalculator
  virtual bool ShouldBeCached(unsigned int complexity_score) = 0;
 
  // Sets a ceiling for the complexity score being calculated. By default
  // this is the largest number representable by an unsigned int.
  //
  // This setting has no effect on non-accumulator based scorers such as
  // the Naive calculator.
  virtual void SetComplexityCeiling(unsigned int ceiling) = 0;
};
 
class DisplayListNaiveComplexityCalculator
    : public DisplayListComplexityCalculator {
 public:
  static DisplayListComplexityCalculator* GetInstance();
 
  unsigned int Compute(const DisplayList* display_list) override {
    return display_list->op_count(true);
  }
 
  bool ShouldBeCached(unsigned int complexity_score) override {
    return complexity_score > 5u;
  }
 
  void SetComplexityCeiling(unsigned int ceiling) override {}
 
 private:
  DisplayListNaiveComplexityCalculator() {}
  static DisplayListNaiveComplexityCalculator* instance_;
};
 
}  // namespace flutter
 
#endif  // FLUTTER_DISPLAY_LIST_BENCHMARKING_DL_COMPLEXITY_H_