//////////////////////////////////////////////////////////////////////////////

//

// (C) Copyright Ion Gaztanaga 2006. Distributed under the Boost

// Software License, Version 1.0. (See accompanying file

// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

//

// See http://www.boost.org/libs/interprocess for documentation.

//

//////////////////////////////////////////////////////////////////////////////



#ifndef BOOST_INTERPROCESS_DETAIL_FILE_WRAPPER_HPP

#define BOOST_INTERPROCESS_DETAIL_FILE_WRAPPER_HPP



#include <boost/interprocess/detail/config_begin.hpp>

#include <boost/interprocess/detail/workaround.hpp>

#include <boost/interprocess/detail/os_file_functions.hpp>

#include <boost/interprocess/creation_tags.hpp>

#include <boost/interprocess/detail/move.hpp>

#include <boost/interprocess/creation_tags.hpp>



namespace boost {

namespace interprocess {

namespace detail{



class file_wrapper

{

   public:



   //!Default constructor.

   //!Represents an empty file_wrapper.

   file_wrapper();



   //!Creates a file object with name "name" and mode "mode", with the access mode "mode"

   //!If the file previously exists, throws an error.

   file_wrapper(create_only_t, const char *name, mode_t mode)

   {  this->priv_open_or_create(detail::DoCreate, name, mode);  }



   //!Tries to create a file with name "name" and mode "mode", with the

   //!access mode "mode". If the file previously exists, it tries to open it with mode "mode".

   //!Otherwise throws an error.

   file_wrapper(open_or_create_t, const char *name, mode_t mode)

   {  this->priv_open_or_create(detail::DoOpenOrCreate, name, mode);  }



   //!Tries to open a file with name "name", with the access mode "mode". 

   //!If the file does not previously exist, it throws an error.

   file_wrapper(open_only_t, const char *name, mode_t mode)

   {  this->priv_open_or_create(detail::DoOpen, name, mode);  }



   //!Moves the ownership of "moved"'s file to *this. 

   //!After the call, "moved" does not represent any file. 

   //!Does not throw

   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE

   file_wrapper

      (detail::moved_object<file_wrapper> &moved)

   {  this->swap(moved.get());   }

   #else

   file_wrapper(file_wrapper &&moved)

   {  this->swap(moved);   }

   #endif



   //!Moves the ownership of "moved"'s file to *this.

   //!After the call, "moved" does not represent any file.

   //!Does not throw

   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE

   file_wrapper &operator=

      (detail::moved_object<file_wrapper> &moved)

   {  

      file_wrapper tmp(moved);

      this->swap(tmp);

      return *this;  

   }

   #else

   file_wrapper &operator=(file_wrapper &&moved)

   {  

      file_wrapper tmp(move(moved));

      this->swap(tmp);

      return *this;  

   }

   #endif



   //!Swaps to file_wrappers.

   //!Does not throw

   void swap(file_wrapper &other);



   //!Erases a file from the system.

   //!Returns false on error. Never throws

   static bool remove(const char *name);

   

   //!Sets the size of the file

   void truncate(offset_t length);



   //!Closes the

   //!file

   ~file_wrapper();



   //!Returns the name of the file

   //!used in the constructor

   const char *get_name() const;



   //!Returns the name of the file

   //!used in the constructor

   bool get_size(offset_t &size) const;



   //!Returns access mode

   //!used in the constructor

   mode_t get_mode() const;



   //!Get mapping handle

   //!to use with mapped_region

   mapping_handle_t get_mapping_handle() const;



   private:

   //!Closes a previously opened file mapping. Never throws.

   void priv_close();

   //!Closes a previously opened file mapping. Never throws.

   bool priv_open_or_create(detail::create_enum_t type, const char *filename, mode_t mode);



   file_handle_t  m_handle;

   mode_t      m_mode;

   std::string       m_filename;

};



inline file_wrapper::file_wrapper() 

   :  m_handle(file_handle_t(detail::invalid_file()))

{}



inline file_wrapper::~file_wrapper() 

{  this->priv_close(); }



inline const char *file_wrapper::get_name() const

{  return m_filename.c_str(); }



inline bool file_wrapper::get_size(offset_t &size) const

{  return get_file_size((file_handle_t)m_handle, size);  }



inline void file_wrapper::swap(file_wrapper &other)

{  

   std::swap(m_handle,  other.m_handle);

   std::swap(m_mode,    other.m_mode);

   m_filename.swap(other.m_filename);   

}



inline mapping_handle_t file_wrapper::get_mapping_handle() const

{  return mapping_handle_from_file_handle(m_handle);  }



inline mode_t file_wrapper::get_mode() const

{  return m_mode; }



inline bool file_wrapper::priv_open_or_create

   (detail::create_enum_t type, 

    const char *filename,

    mode_t mode)

{

   m_filename = filename;



   if(mode != read_only && mode != read_write){

      error_info err(mode_error);

      throw interprocess_exception(err);

   }



   //Open file existing native API to obtain the handle

   switch(type){

      case detail::DoOpen:

         m_handle = open_existing_file(filename, mode);

      break;

      case detail::DoCreate:

         m_handle = create_new_file(filename, mode);

      break;

      case detail::DoOpenOrCreate:

         m_handle = create_or_open_file(filename, mode);

      break;

      default:

         {

            error_info err = other_error;

            throw interprocess_exception(err);

         }

   }



   //Check for error

   if(m_handle == invalid_file()){

      throw interprocess_exception(error_info(system_error_code()));

   }



   m_mode = mode;

   return true;

}



inline bool file_wrapper::remove(const char *filename)

{  return delete_file(filename); }



inline void file_wrapper::truncate(offset_t length)

{

   if(!truncate_file(m_handle, length)){

      error_info err(system_error_code());

      throw interprocess_exception(err);

   }

}



inline void file_wrapper::priv_close()

{

   if(m_handle != invalid_file()){

      close_file(m_handle);

      m_handle = invalid_file();

   }

}



}  //namespace detail{

}  //namespace interprocess {

}  //namespace boost {



#include <boost/interprocess/detail/config_end.hpp>



#endif   //BOOST_INTERPROCESS_DETAIL_FILE_WRAPPER_HPP

