Posix_File.h

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#ifndef joedb_Posix_File_declared
#define joedb_Posix_File_declared
 
#include "joedb/journal/Abstract_File.h"
 
#include <fcntl.h>
#include <unistd.h>
#include <string>
 
#ifndef F_OFD_SETLK
#define JOEDB_HAS_BROKEN_POSIX_LOCKING
#endif
 
namespace joedb
{
 ////////////////////////////////////////////////////////////////////////////
 class Posix_FD: public Abstract_File
 ////////////////////////////////////////////////////////////////////////////
 {
  private:
   int fd;
   int lock(int command, short type, int64_t start, int64_t size);
 
  protected:
   bool try_exclusive_lock(int64_t start, int64_t size);
 
  public:
   static void throw_last_error(const char *action, const char *file_name);
 
   Posix_FD(int fd, Open_Mode mode):
    Abstract_File(mode),
    fd(fd)
   {
   }
 
   Posix_FD(const char *file_name, Open_Mode mode);
 
   Posix_FD(const Posix_FD &) = delete;
   Posix_FD &operator=(const Posix_FD &) = delete;
 
   int64_t get_size() const override;
   size_t pread(char *buffer, size_t size, int64_t offset) const override;
   void pwrite(const char *buffer, size_t size, int64_t offset) override;
 
   void sync() override;
#if _POSIX_SYNCHRONIZED_IO > 0
   void datasync() override;
#endif
 
   void shared_lock(int64_t start, int64_t size) override;
   void exclusive_lock(int64_t start, int64_t size) override;
   void unlock(int64_t start, int64_t size) noexcept override;
 
   ~Posix_FD() override;
 };
 
 /// @ingroup journal
 class Posix_File: public Posix_FD
 {
  public:
   static constexpr bool lockable = true;
#ifdef JOEDB_HAS_BROKEN_POSIX_LOCKING
   static constexpr bool has_broken_posix_locking = true;
#else
   static constexpr bool has_broken_posix_locking = false;
#endif
 
   Posix_File(int fd, Open_Mode mode):
    Posix_FD(fd, mode)
   {
   }
 
   Posix_File(const char *file_name, Open_Mode mode);
 
   Posix_File(const std::string &file_name, Open_Mode mode):
    Posix_File(file_name.c_str(), mode)
   {
   }
 };
}
 
#endif