BC_ReedSolomonGF256.h

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// Copyright 2014 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
#ifndef FXBARCODE_COMMON_REEDSOLOMON_BC_REEDSOLOMONGF256_H_
#define FXBARCODE_COMMON_REEDSOLOMON_BC_REEDSOLOMONGF256_H_
 
#include <memory>
 
#include "third_party/abseil-cpp/absl/types/optional.h"
 
class CBC_ReedSolomonGF256Poly;
 
class CBC_ReedSolomonGF256 {
 public:
  explicit CBC_ReedSolomonGF256(int32_t primitive);
  ~CBC_ReedSolomonGF256();
 
  CBC_ReedSolomonGF256Poly* GetZero() const { return m_zero.get(); }
  CBC_ReedSolomonGF256Poly* GetOne() const { return m_one.get(); }
 
  std::unique_ptr<CBC_ReedSolomonGF256Poly> BuildMonomial(int32_t degree,
                                                          int32_t coefficient);
  static int32_t AddOrSubtract(int32_t a, int32_t b);
  int32_t Exp(int32_t a);
  absl::optional<int32_t> Inverse(int32_t a);
  int32_t Multiply(int32_t a, int32_t b);
  void Init();
 
 private:
  std::unique_ptr<CBC_ReedSolomonGF256Poly> m_zero;
  std::unique_ptr<CBC_ReedSolomonGF256Poly> m_one;
  int32_t m_expTable[256];
  int32_t m_logTable[256];
};
 
#endif  // FXBARCODE_COMMON_REEDSOLOMON_BC_REEDSOLOMONGF256_H_