ceph/src/boost/boost/interprocess/detail/file_wrapper.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2006-2012. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/interprocess for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef BOOST_INTERPROCESS_DETAIL_FILE_WRAPPER_HPP
  12 #define BOOST_INTERPROCESS_DETAIL_FILE_WRAPPER_HPP
  13
  14 #ifndef BOOST_CONFIG_HPP
  15 #  include <boost/config.hpp>
  16 #endif
  17 #
  18 #if defined(BOOST_HAS_PRAGMA_ONCE)
  19 #  pragma once
  20 #endif
  21
  22 #include <boost/interprocess/detail/config_begin.hpp>
  23 #include <boost/interprocess/detail/workaround.hpp>
  24 #include <boost/interprocess/detail/os_file_functions.hpp>
  25 #include <boost/interprocess/creation_tags.hpp>
  26 #include <boost/move/utility_core.hpp>
  27 #include <boost/interprocess/creation_tags.hpp>
  28 #include <boost/interprocess/detail/simple_swap.hpp>
  29
  30 namespace boost {
  31 namespace interprocess {
  32 namespace ipcdetail{
  33
  34 class file_wrapper
  35 {
  36    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  37    BOOST_MOVABLE_BUT_NOT_COPYABLE(file_wrapper)
  38    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  39    public:
  40
  41    //!Default constructor.
  42    //!Represents an empty file_wrapper.
  43    file_wrapper();
  44
  45    //!Creates a file object with name "name" and mode "mode", with the access mode "mode"
  46    //!If the file previously exists, throws an error.
  47    file_wrapper(create_only_t, const char *name, mode_t mode, const permissions &perm = permissions())
  48    {  this->priv_open_or_create(ipcdetail::DoCreate, name, mode, perm);  }
  49
  50    //!Tries to create a file with name "name" and mode "mode", with the
  51    //!access mode "mode". If the file previously exists, it tries to open it with mode "mode".
  52    //!Otherwise throws an error.
  53    file_wrapper(open_or_create_t, const char *name, mode_t mode, const permissions &perm  = permissions())
  54    {  this->priv_open_or_create(ipcdetail::DoOpenOrCreate, name, mode, perm);  }
  55
  56    //!Tries to open a file with name "name", with the access mode "mode".
  57    //!If the file does not previously exist, it throws an error.
  58    file_wrapper(open_only_t, const char *name, mode_t mode)
  59    {  this->priv_open_or_create(ipcdetail::DoOpen, name, mode, permissions());  }
  60
  61    //!Moves the ownership of "moved"'s file to *this.
  62    //!After the call, "moved" does not represent any file.
  63    //!Does not throw
  64    file_wrapper(BOOST_RV_REF(file_wrapper) moved)
  65       :  m_handle(file_handle_t(ipcdetail::invalid_file()))
  66    {  this->swap(moved);   }
  67
  68    //!Moves the ownership of "moved"'s file to *this.
  69    //!After the call, "moved" does not represent any file.
  70    //!Does not throw
  71    file_wrapper &operator=(BOOST_RV_REF(file_wrapper) moved)
  72    {
  73       file_wrapper tmp(boost::move(moved));
  74       this->swap(tmp);
  75       return *this;
  76    }
  77
  78    //!Swaps to file_wrappers.
  79    //!Does not throw
  80    void swap(file_wrapper &other);
  81
  82    //!Erases a file from the system.
  83    //!Returns false on error. Never throws
  84    static bool remove(const char *name);
  85
  86    //!Sets the size of the file
  87    void truncate(offset_t length);
  88
  89    //!Closes the
  90    //!file
  91    ~file_wrapper();
  92
  93    //!Returns the name of the file
  94    //!used in the constructor
  95    const char *get_name() const;
  96
  97    //!Returns the name of the file
  98    //!used in the constructor
  99    bool get_size(offset_t &size) const;
 100
 101    //!Returns access mode
 102    //!used in the constructor
 103    mode_t get_mode() const;
 104
 105    //!Get mapping handle
 106    //!to use with mapped_region
 107    mapping_handle_t get_mapping_handle() const;
 108
 109    private:
 110    //!Closes a previously opened file mapping. Never throws.
 111    void priv_close();
 112    //!Closes a previously opened file mapping. Never throws.
 113    bool priv_open_or_create(ipcdetail::create_enum_t type, const char *filename, mode_t mode, const permissions &perm);
 114
 115    file_handle_t  m_handle;
 116    mode_t      m_mode;
 117    std::string       m_filename;
 118 };
 119
 120 inline file_wrapper::file_wrapper()
 121    :  m_handle(file_handle_t(ipcdetail::invalid_file()))
 122 {}
 123
 124 inline file_wrapper::~file_wrapper()
 125 {  this->priv_close(); }
 126
 127 inline const char *file_wrapper::get_name() const
 128 {  return m_filename.c_str(); }
 129
 130 inline bool file_wrapper::get_size(offset_t &size) const
 131 {  return get_file_size((file_handle_t)m_handle, size);  }
 132
 133 inline void file_wrapper::swap(file_wrapper &other)
 134 {
 135    (simple_swap)(m_handle,  other.m_handle);
 136    (simple_swap)(m_mode,    other.m_mode);
 137    m_filename.swap(other.m_filename);
 138 }
 139
 140 inline mapping_handle_t file_wrapper::get_mapping_handle() const
 141 {  return mapping_handle_from_file_handle(m_handle);  }
 142
 143 inline mode_t file_wrapper::get_mode() const
 144 {  return m_mode; }
 145
 146 inline bool file_wrapper::priv_open_or_create
 147    (ipcdetail::create_enum_t type,
 148     const char *filename,
 149     mode_t mode,
 150     const permissions &perm = permissions())
 151 {
 152    m_filename = filename;
 153
 154    if(mode != read_only && mode != read_write){
 155       error_info err(mode_error);
 156       throw interprocess_exception(err);
 157    }
 158
 159    //Open file existing native API to obtain the handle
 160    switch(type){
 161       case ipcdetail::DoOpen:
 162          m_handle = open_existing_file(filename, mode);
 163       break;
 164       case ipcdetail::DoCreate:
 165          m_handle = create_new_file(filename, mode, perm);
 166       break;
 167       case ipcdetail::DoOpenOrCreate:
 168          m_handle = create_or_open_file(filename, mode, perm);
 169       break;
 170       default:
 171          {
 172             error_info err = other_error;
 173             throw interprocess_exception(err);
 174          }
 175    }
 176
 177    //Check for error
 178    if(m_handle == invalid_file()){
 179       error_info err = system_error_code();
 180       throw interprocess_exception(err);
 181    }
 182
 183    m_mode = mode;
 184    return true;
 185 }
 186
 187 inline bool file_wrapper::remove(const char *filename)
 188 {  return delete_file(filename); }
 189
 190 inline void file_wrapper::truncate(offset_t length)
 191 {
 192    if(!truncate_file(m_handle, length)){
 193       error_info err(system_error_code());
 194       throw interprocess_exception(err);
 195    }
 196 }
 197
 198 inline void file_wrapper::priv_close()
 199 {
 200    if(m_handle != invalid_file()){
 201       close_file(m_handle);
 202       m_handle = invalid_file();
 203    }
 204 }
 205
 206 }  //namespace ipcdetail{
 207 }  //namespace interprocess {
 208 }  //namespace boost {
 209
 210 #include <boost/interprocess/detail/config_end.hpp>
 211
 212 #endif   //BOOST_INTERPROCESS_DETAIL_FILE_WRAPPER_HPP