random_access_file_type.h

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */
 
#ifndef RANDOM_ACCESS_FILE_TYPE_H
#define RANDOM_ACCESS_FILE_TYPE_H
 
#include "fileio_type.h"
 
class RandomAccessFile {
  static constexpr int BUFFER_SIZE = 512;
 
  std::string filename;            
  std::string simplified_filename; 
 
  std::optional<FileHandle> file_handle; 
  size_t pos;                      
  size_t start_pos; 
  size_t end_pos; 
 
  uint8_t *buffer;                    
  uint8_t *buffer_end;                
  uint8_t buffer_start[BUFFER_SIZE];  
 
public:
  RandomAccessFile(std::string_view filename, Subdirectory subdir);
  RandomAccessFile(const RandomAccessFile&) = delete;
  void operator=(const RandomAccessFile&) = delete;
 
  virtual ~RandomAccessFile() = default;
 
  const std::string &GetFilename() const;
  const std::string &GetSimplifiedFilename() const;
 
  size_t GetPos() const;
  size_t GetStartPos() const { return this->start_pos; }
  size_t GetEndPos() const { return this->end_pos; }
  void SeekTo(size_t pos, int mode);
  bool AtEndOfFile() const;
 
  uint8_t ReadByte();
  uint16_t ReadWord();
  uint32_t ReadDword();
 
  void ReadBlock(void *ptr, size_t size);
  void SkipBytes(size_t n);
};
 
#endif /* RANDOM_ACCESS_FILE_TYPE_H */