double_buffer.hpp

#pragma once
 
#include <cstddef>
#include <cstdint>
#include <cstring>
 
#include "libxr_assert.hpp"
#include "libxr_type.hpp"  // RawData
 
namespace LibXR
{
class DoubleBuffer
{
 public:
  DoubleBuffer() = default;
 
  explicit DoubleBuffer(const LibXR::RawData& raw_data);
 
  void Init(const LibXR::RawData& raw_data);
 
  void Reset();
 
  uint8_t* ActiveBuffer() const;
 
  uint8_t* PendingBuffer() const;
 
  uint8_t* Buffer(int block) const;
 
  size_t Size() const;
 
  void Switch();
 
  bool HasPending() const;
 
  bool FillPending(const uint8_t* data, size_t len);
 
  bool FillActive(const uint8_t* data, size_t len);
 
  void EnablePending();
 
  size_t GetPendingLength() const;
 
  size_t GetActiveLength() const { return active_len_; }
 
  void SetPendingLength(size_t length) { pending_len_ = length; }
 
  void SetActiveLength(size_t length) { active_len_ = length; }
 
  void FlipActiveBlock() { active_ ^= 1; }
 
  int ActiveBlock() const { return active_; }
 
  void SetActiveBlock(bool block) { active_ = block ? 1 : 0; }
 
 private:
  uint8_t* buffer_[2] = {nullptr, nullptr};  
  size_t size_ = 0;                          
  int active_ = 0;  
  bool pending_valid_ =
      false;                
  size_t active_len_ = 0;   
  size_t pending_len_ = 0;  
};
}  // namespace LibXR