interprocess/indexes/map_index.hpp

0001 //////////////////////////////////////////////////////////////////////////////
0002 //
0003 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
0004 // Software License, Version 1.0. (See accompanying file
0005 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // See http://www.boost.org/libs/interprocess for documentation.
0008 //
0009 //////////////////////////////////////////////////////////////////////////////
0010
0011 #ifndef BOOST_INTERPROCESS_MAP_INDEX_HPP
0012 #define BOOST_INTERPROCESS_MAP_INDEX_HPP
0013
0014 #ifndef BOOST_CONFIG_HPP
0015 #  include <boost/config.hpp>
0016 #endif
0017 #
0018 #if defined(BOOST_HAS_PRAGMA_ONCE)
0019 #  pragma once
0020 #endif
0021
0022 #include <boost/interprocess/detail/config_begin.hpp>
0023 #include <boost/interprocess/detail/workaround.hpp>
0024
0025 #include <boost/intrusive/detail/minimal_pair_header.hpp>
0026 #include <boost/interprocess/containers/map.hpp>
0027 #include <boost/interprocess/allocators/private_adaptive_pool.hpp>
0028 #include <boost/intrusive/detail/minimal_pair_header.hpp>         //std::pair
0029 #include <boost/intrusive/detail/minimal_less_equal_header.hpp>   //std::less
0030
0031 //!\file
0032 //!Describes index adaptor of boost::map container, to use it
0033 //!as name/shared memory index
0034
0035 namespace boost {
0036 namespace interprocess {
0037 namespace ipcdetail{
0038
0039 //!Helper class to define typedefs from IndexTraits
0040 template <class MapConfig>
0041 struct map_index_aux
0042 {
0043    typedef typename MapConfig::key_type            key_type;
0044    typedef typename MapConfig::mapped_type         mapped_type;
0045    typedef std::less<key_type>                     key_less;
0046    typedef std::pair<const key_type, mapped_type>  value_type;
0047
0048    typedef private_adaptive_pool
0049             <value_type,
0050                typename MapConfig::
0051          segment_manager_base>                     allocator_type;
0052
0053    typedef boost::interprocess::map
0054       <key_type,  mapped_type,
0055        key_less, allocator_type>                   index_t;
0056 };
0057
0058 }  //namespace ipcdetail {
0059
0060 //!Index type based in boost::interprocess::map. Just derives from boost::interprocess::map
0061 //!and defines the interface needed by managed memory segments
0062 template <class MapConfig>
0063 class map_index
0064    //Derive class from map specialization
0065    : public ipcdetail::map_index_aux<MapConfig>::index_t
0066 {
0067    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
0068    typedef ipcdetail::map_index_aux<MapConfig>  index_aux;
0069    typedef typename index_aux::index_t       base_type;
0070    typedef typename MapConfig::
0071       segment_manager_base          segment_manager_base;
0072    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
0073
0074    public:
0075    //!Constructor. Takes a pointer to the
0076    //!segment manager. Can throw
0077    map_index(segment_manager_base *segment_mngr)
0078       : base_type(typename index_aux::key_less(),
0079                   segment_mngr){}
0080
0081    //!This reserves memory to optimize the insertion of n
0082    //!elements in the index
0083    void reserve(typename segment_manager_base::size_type)
0084       {  /*Does nothing, map has not reserve or rehash*/  }
0085
0086    //!This tries to free previously allocate
0087    //!unused memory.
0088    void shrink_to_fit()
0089    {  base_type::get_stored_allocator().deallocate_free_blocks(); }
0090 };
0091
0092 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
0093
0094 //!Trait class to detect if an index is a node
0095 //!index. This allows more efficient operations
0096 //!when deallocating named objects.
0097 template<class MapConfig>
0098 struct is_node_index
0099    <boost::interprocess::map_index<MapConfig> >
0100 {
0101    static const bool value = true;
0102 };
0103 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
0104
0105 }}   //namespace boost { namespace interprocess {
0106
0107 #include <boost/interprocess/detail/config_end.hpp>
0108
0109 #endif   //#ifndef BOOST_INTERPROCESS_MAP_INDEX_HPP