text: /*************************************************************************/
  /*  file_access.h                                                        */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
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  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #ifndef FILE_ACCESS_H
  #define FILE_ACCESS_H
  
  #include "core/math/math_defs.h"
  #include "core/os/memory.h"
  #include "core/typedefs.h"
  #include "core/ustring.h"
  
  /**
   * Multi-Platform abstraction for accessing to files.
   */
  
  class FileAccess {
  
  public:
  	enum AccessType {
  		ACCESS_RESOURCES,
  		ACCESS_USERDATA,
  		ACCESS_FILESYSTEM,
  		ACCESS_MAX
  	};
  
  	typedef void (*FileCloseFailNotify)(const String &);
  
  	typedef FileAccess *(*CreateFunc)();
  	bool endian_swap;
  	bool real_is_double;
  
  protected:
  	String fix_path(const String &p_path) const;
  	virtual Error _open(const String &p_path, int p_mode_flags) = 0; ///< open a file
  	virtual uint64_t _get_modified_time(const String &p_file) = 0;
  
  	static FileCloseFailNotify close_fail_notify;
  
  private:
  	static bool backup_save;
  
  	AccessType _access_type;
  	static CreateFunc create_func[ACCESS_MAX]; /** default file access creation function for a platform */
  	template <class T>
  	static FileAccess *_create_builtin() {
  
  		return memnew(T);
  	}
  
  public:
  	static void set_file_close_fail_notify_callback(FileCloseFailNotify p_cbk) { close_fail_notify = p_cbk; }
  
  	virtual void _set_access_type(AccessType p_access);
  
  	enum ModeFlags {
  
  		READ = 1,
  		WRITE = 2,
  		READ_WRITE = 3,
  		WRITE_READ = 7,
  	};
  
  	virtual void close() = 0; ///< close a file
  	virtual bool is_open() const = 0; ///< true when file is open
  
  	virtual String get_path() const { return ""; } /// returns the path for the current open file
  	virtual String get_path_absolute() const { return ""; } /// returns the absolute path for the current open file
  
  	virtual void seek(size_t p_position) = 0; ///< seek to a given position
  	virtual void seek_end(int64_t p_position = 0) = 0; ///< seek from the end of file
  	virtual size_t get_position() const = 0; ///< get position in the file
  	virtual size_t get_len() const = 0; ///< get size of the file
  
  	virtual bool eof_reached() const = 0; ///< reading passed EOF
  
  	virtual uint8_t get_8() const = 0; ///< get a byte
  	virtual uint16_t get_16() const; ///< get 16 bits uint
  	virtual uint32_t get_32() const; ///< get 32 bits uint
  	virtual uint64_t get_64() const; ///< get 64 bits uint
  
  	virtual float get_float() const;
  	virtual double get_double() const;
  	virtual real_t get_real() const;
  
  	virtual int get_buffer(uint8_t *p_dst, int p_length) const; ///< get an array of bytes
  	virtual String get_line() const;
  	virtual String get_token() const;
  	virtual Vector<String> get_csv_line(String delim = ",") const;
  
  	/**< use this for files WRITTEN in _big_ endian machines (ie, amiga/mac)
  	 * It's not about the current CPU type but file formats.
  	 * this flags get reset to false (little endian) on each open
  	 */
  
  	virtual void set_endian_swap(bool p_swap) { endian_swap = p_swap; }
  	inline bool get_endian_swap() const { return endian_swap; }
  
  	virtual Error get_error() const = 0; ///< get last error
  
  	virtual void flush() = 0;
  	virtual void store_8(uint8_t p_dest) = 0; ///< store a byte
  	virtual void store_16(uint16_t p_dest); ///< store 16 bits uint
  	virtual void store_32(uint32_t p_dest); ///< store 32 bits uint
  	virtual void store_64(uint64_t p_dest); ///< store 64 bits uint
  
  	virtual void store_float(float p_dest);
  	virtual void store_double(double p_dest);
  	virtual void store_real(real_t p_real);
  
  	virtual void store_string(const String &p_string);
  	virtual void store_line(const String &p_line);
  
  	virtual void store_pascal_string(const String &p_string);
  	virtual String get_pascal_string();
  
  	virtual void store_buffer(const uint8_t *p_src, int p_length); ///< store an array of bytes
  
  	virtual bool file_exists(const String &p_name) = 0; ///< return true if a file exists
  
  	virtual Error reopen(const String &p_path, int p_mode_flags); ///< does not change the AccessType
  
  	virtual Error _chmod(const String &p_path, int p_mod) { return ERR_UNAVAILABLE; }
  
  	static FileAccess *create(AccessType p_access); /// Create a file access (for the current platform) this is the only portable way of accessing files.
  	static FileAccess *create_for_path(const String &p_path);
  	static FileAccess *open(const String &p_path, int p_mode_flags, Error *r_error = NULL); /// Create a file access (for the current platform) this is the only portable way of accessing files.
  	static CreateFunc get_create_func(AccessType p_access);
  	static bool exists(const String &p_name); ///< return true if a file exists
  	static uint64_t get_modified_time(const String &p_file);
  
  	static void set_backup_save(bool p_enable) { backup_save = p_enable; };
  	static bool is_backup_save_enabled() { return backup_save; };
  
  	static String get_md5(const String &p_file);
  	static String get_sha256(const String &p_file);
  	static String get_multiple_md5(const Vector<String> &p_file);
  
  	static Vector<uint8_t> get_file_as_array(const String &p_path);
  
  	template <class T>
  	static void make_default(AccessType p_access) {
  
  		create_func[p_access] = _create_builtin<T>;
  	}
  
  	FileAccess();
  	virtual ~FileAccess() {}
  };
  
  struct FileAccessRef {
  
  	_FORCE_INLINE_ FileAccess *operator->() {
  
  		return f;
  	}
  
  	operator bool() const { return f != NULL; }
  	FileAccess *f;
  	operator FileAccess *() { return f; }
  	FileAccessRef(FileAccess *fa) { f = fa; }
  	~FileAccessRef() {
  		if (f) memdelete(f);
  	}
  };
  
  #endif
  