interprocess/indexes/iunordered_set_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_IUNORDERED_SET_INDEX_HPP
0012 #define BOOST_INTERPROCESS_IUNORDERED_SET_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/interprocess/detail/utilities.hpp>
0026 #include <boost/interprocess/allocators/allocator.hpp>
0027 #include <boost/interprocess/containers/vector.hpp>
0028 #include <boost/intrusive/unordered_set.hpp>
0029 #include <boost/intrusive/detail/minimal_pair_header.hpp>
0030 #include <boost/intrusive/detail/minimal_less_equal_header.hpp>   //std::less
0031 #include <boost/container/detail/minimal_char_traits_header.hpp>  //std::char_traits
0032 #include <boost/container/detail/placement_new.hpp>
0033 #include <boost/intrusive/detail/hash.hpp>
0034
0035 //!\file
0036 //!Describes index adaptor of boost::intrusive::unordered_set container, to use it
0037 //!as name/shared memory index
0038
0039 namespace boost { namespace interprocess {
0040
0041 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
0042
0043 //!Helper class to define typedefs
0044 //!from IndexTraits
0045 template <class MapConfig>
0046 struct iunordered_set_index_aux
0047 {
0048    typedef typename
0049       MapConfig::segment_manager_base                 segment_manager_base;
0050
0051    typedef typename
0052       segment_manager_base::void_pointer              void_pointer;
0053
0054    typedef typename bi::make_unordered_set_base_hook
0055       < bi::void_pointer<void_pointer>
0056       >::type        derivation_hook;
0057
0058    typedef typename MapConfig::template
0059       intrusive_value_type<derivation_hook>::type     value_type;
0060
0061    typedef typename MapConfig::
0062       intrusive_compare_key_type                      intrusive_compare_key_type;
0063
0064    typedef std::equal_to<value_type>                  value_equal;
0065
0066    typedef typename MapConfig::char_type              char_type;
0067
0068    struct equal_function
0069    {
0070       bool operator()(const intrusive_compare_key_type &i, const value_type &b) const
0071       {
0072          return (i.m_len == b.name_length()) &&
0073                   (std::char_traits<char_type>::compare
0074                      (i.mp_str, b.name(), i.m_len) == 0);
0075       }
0076
0077       bool operator()(const value_type &b, const intrusive_compare_key_type &i) const
0078       {
0079          return (i.m_len == b.name_length()) &&
0080                   (std::char_traits<char_type>::compare
0081                      (i.mp_str, b.name(), i.m_len) == 0);
0082       }
0083
0084       bool operator()(const value_type &b1, const value_type &b2) const
0085       {
0086          return (b1.name_length() == b2.name_length()) &&
0087                   (std::char_traits<char_type>::compare
0088                      (b1.name(), b2.name(), b1.name_length()) == 0);
0089       }
0090    };
0091
0092    struct hash_function
0093    {
0094       typedef value_type argument_type;
0095       typedef std::size_t result_type;
0096
0097       std::size_t hash_char_range(const char_type* beg, const char_type* end) const
0098       {
0099          std::size_t seed = 0;
0100          while (beg != end) {
0101             boost::intrusive::detail::hash_combine_size_t(seed, boost::intrusive::detail::internal_hash_functor<char_type>()(*beg));
0102             ++beg;
0103          }
0104          return seed;
0105       }
0106
0107       std::size_t operator()(const value_type &val) const
0108       {
0109          const char_type* beg = ipcdetail::to_raw_pointer(val.name()),
0110                         * end = beg + val.name_length();
0111          return hash_char_range(beg, end);
0112       }
0113
0114       std::size_t operator()(const intrusive_compare_key_type &i) const
0115       {
0116          const char_type *beg = i.mp_str,
0117                            *end = beg + i.m_len;
0118          return hash_char_range(beg, end);
0119       }
0120    };
0121
0122    typedef typename bi::make_unordered_set
0123       < value_type
0124       , bi::hash<hash_function>
0125       , bi::equal<equal_function>
0126      , bi::size_type<typename segment_manager_base::size_type>
0127       >::type                                         index_t;
0128    typedef typename index_t::bucket_type              bucket_type;
0129    typedef allocator
0130       <bucket_type, segment_manager_base>             allocator_type;
0131
0132    struct allocator_holder
0133    {
0134       allocator_holder(segment_manager_base *mngr)
0135          :  alloc(mngr)
0136       {}
0137       allocator_type alloc;
0138       bucket_type init_bucket;
0139    };
0140 };
0141 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
0142
0143 //!Index type based in boost::intrusive::set.
0144 //!Just derives from boost::intrusive::set
0145 //!and defines the interface needed by managed memory segments
0146 template <class MapConfig>
0147 class iunordered_set_index
0148       //Derive class from map specialization
0149    :  private iunordered_set_index_aux<MapConfig>::allocator_holder
0150    ,  public iunordered_set_index_aux<MapConfig>::index_t
0151 {
0152    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
0153    typedef iunordered_set_index_aux<MapConfig>           index_aux;
0154    typedef typename index_aux::index_t                   index_type;
0155    typedef typename MapConfig::
0156       intrusive_compare_key_type                         intrusive_compare_key_type;
0157    typedef typename index_aux::equal_function            equal_function;
0158    typedef typename index_aux::hash_function             hash_function;
0159    typedef typename MapConfig::char_type                 char_type;
0160    typedef typename
0161       iunordered_set_index_aux<MapConfig>::allocator_type      allocator_type;
0162    typedef typename
0163       iunordered_set_index_aux<MapConfig>::allocator_holder    allocator_holder;
0164    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
0165
0166    public:
0167    typedef typename index_type::iterator                 iterator;
0168    typedef typename index_type::const_iterator           const_iterator;
0169    typedef typename index_type::insert_commit_data       insert_commit_data;
0170    typedef typename index_type::value_type               value_type;
0171    typedef typename index_type::bucket_ptr               bucket_ptr;
0172    typedef typename index_type::bucket_type              bucket_type;
0173    typedef typename index_type::bucket_traits            bucket_traits;
0174    typedef typename index_type::size_type                size_type;
0175    typedef typename index_type::difference_type          difference_type;
0176
0177    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
0178    private:
0179    typedef typename index_aux::
0180       segment_manager_base             segment_manager_base;
0181
0182    static const std::size_t InitBufferSize = 64;
0183
0184    static bucket_ptr create_buckets(allocator_type &alloc, size_type num)
0185    {
0186       num = index_type::suggested_upper_bucket_count(num);
0187       bucket_ptr buckets = alloc.allocate(num);
0188       bucket_ptr buckets_init = buckets;
0189       for(size_type i = 0; i < num; ++i){
0190          ::new(to_raw_pointer(buckets_init++), boost_container_new_t())bucket_type();
0191       }
0192       return buckets;
0193    }
0194
0195    static size_type shrink_buckets
0196       ( bucket_ptr buckets, size_type old_size
0197       , allocator_type &alloc, size_type new_size)
0198    {
0199       if(old_size <= new_size )
0200          return old_size;
0201       size_type received_size = new_size;
0202       if(!alloc.allocation_command
0203          (boost::interprocess::try_shrink_in_place | boost::interprocess::nothrow_allocation, old_size, received_size, buckets)){
0204          return old_size;
0205       }
0206
0207       for( bucket_type *p = ipcdetail::to_raw_pointer(buckets) + received_size
0208          , *pend = ipcdetail::to_raw_pointer(buckets) + old_size
0209          ; p != pend
0210          ; ++p){
0211          p->~bucket_type();
0212       }
0213
0214       bucket_ptr shunk_p = alloc.allocation_command
0215          (boost::interprocess::shrink_in_place | boost::interprocess::nothrow_allocation, received_size, received_size, buckets);
0216       BOOST_ASSERT(buckets == shunk_p); (void)shunk_p;
0217
0218       bucket_ptr buckets_init = buckets + difference_type(received_size);
0219       for(size_type i = 0; i < (old_size - received_size); ++i){
0220          to_raw_pointer(buckets_init++)->~bucket_type();
0221       }
0222       return received_size;
0223    }
0224
0225    static bucket_ptr expand_or_create_buckets
0226       ( bucket_ptr old_buckets, const size_type old_num
0227       , allocator_type &alloc,  const size_type new_num)
0228    {
0229       size_type received_size = new_num;
0230       bucket_ptr reuse(old_buckets);
0231       bucket_ptr ret = alloc.allocation_command
0232             (boost::interprocess::expand_fwd | boost::interprocess::allocate_new, new_num, received_size, reuse);
0233       if(ret == old_buckets){
0234          bucket_ptr buckets_init = old_buckets + difference_type(old_num);
0235          for(size_type i = 0; i < (new_num - old_num); ++i){
0236             ::new(to_raw_pointer(buckets_init++), boost_container_new_t())bucket_type();
0237          }
0238       }
0239       else{
0240          bucket_ptr buckets_init = ret;
0241          for(size_type i = 0; i < new_num; ++i){
0242             ::new(to_raw_pointer(buckets_init++), boost_container_new_t())bucket_type();
0243          }
0244       }
0245       return ret;
0246    }
0247
0248    static void destroy_buckets
0249       (allocator_type &alloc, bucket_ptr buckets, size_type num)
0250    {
0251       bucket_ptr buckets_destroy = buckets;
0252       for(size_type i = 0; i < num; ++i){
0253          to_raw_pointer(buckets_destroy++)->~bucket_type();
0254       }
0255       alloc.deallocate(buckets, num);
0256    }
0257
0258    iunordered_set_index<MapConfig>* get_this_pointer()
0259    {  return this;   }
0260
0261    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
0262
0263    public:
0264    //!Constructor. Takes a pointer to the
0265    //!segment manager. Can throw
0266    iunordered_set_index(segment_manager_base *mngr)
0267       :  allocator_holder(mngr)
0268       ,  index_type(bucket_traits(&get_this_pointer()->init_bucket, 1))
0269    {}
0270
0271    ~iunordered_set_index()
0272    {
0273       index_type::clear();
0274       if(index_type::bucket_pointer() != bucket_ptr(&this->init_bucket)){
0275          destroy_buckets(this->alloc, index_type::bucket_pointer(), index_type::bucket_count());
0276       }
0277    }
0278
0279    //!This reserves memory to optimize the insertion of n
0280    //!elements in the index
0281    void reserve(size_type new_n)
0282    {
0283       //Let's maintain a 1.0f load factor
0284       size_type old_n  = this->bucket_count();
0285       if(new_n <= old_n)
0286          return;
0287       bucket_ptr old_p = this->bucket_pointer();
0288       new_n = index_type::suggested_upper_bucket_count(new_n);
0289       bucket_ptr new_p;
0290       //This can throw
0291       BOOST_TRY{
0292          if(old_p != bucket_ptr(&this->init_bucket))
0293             new_p = expand_or_create_buckets(old_p, old_n, this->alloc, new_n);
0294          else
0295             new_p = create_buckets(this->alloc, new_n);
0296       }
0297       BOOST_CATCH(...){
0298          return;
0299       } BOOST_CATCH_END
0300       //Rehashing does not throw, since neither the hash nor the
0301       //comparison function can throw
0302       this->rehash(bucket_traits(new_p, new_n));
0303       if(new_p != old_p && old_p != bucket_ptr(&this->init_bucket)){
0304          destroy_buckets(this->alloc, old_p, old_n);
0305       }
0306    }
0307
0308    //!This tries to free unused memory
0309    //!previously allocated.
0310    void shrink_to_fit()
0311    {
0312       size_type cur_size   = this->size();
0313       size_type cur_count  = this->bucket_count();
0314       bucket_ptr old_p = this->bucket_pointer();
0315
0316       if(!this->size() && old_p != bucket_ptr(&this->init_bucket)){
0317          this->rehash(bucket_traits(bucket_ptr(&this->init_bucket), 1));
0318          destroy_buckets(this->alloc, old_p, cur_count);
0319       }
0320       else{
0321          size_type sug_count = 0; //gcc warning
0322          sug_count = index_type::suggested_upper_bucket_count(cur_size);
0323
0324          if(sug_count >= cur_count)
0325             return;
0326
0327          BOOST_TRY{
0328             shrink_buckets(old_p, cur_count, this->alloc, sug_count);
0329          }
0330          BOOST_CATCH(...){
0331             return;
0332          } BOOST_CATCH_END
0333
0334          //Rehashing does not throw, since neither the hash nor the
0335          //comparison function can throw
0336          this->rehash(bucket_traits(old_p, sug_count));
0337       }
0338    }
0339
0340    iterator find(const intrusive_compare_key_type &key)
0341    {  return index_type::find(key, hash_function(), equal_function());  }
0342
0343    const_iterator find(const intrusive_compare_key_type &key) const
0344    {  return index_type::find(key, hash_function(), equal_function());  }
0345
0346    std::pair<iterator, bool>insert_check
0347       (const intrusive_compare_key_type &key, insert_commit_data &commit_data)
0348    {  return index_type::insert_check(key, hash_function(), equal_function(), commit_data); }
0349
0350    iterator insert_commit(value_type &val, insert_commit_data &commit_data)
0351    {
0352       iterator it = index_type::insert_commit(val, commit_data);
0353       size_type cur_size      = this->size();
0354       if(cur_size > this->bucket_count()){
0355          BOOST_TRY{
0356             this->reserve(cur_size);
0357          }
0358          BOOST_CATCH(...){
0359             //Strong guarantee: if something goes wrong
0360             //we should remove the insertion.
0361             //
0362             //We can use the iterator because the hash function
0363             //can't throw and this means that "reserve" will
0364             //throw only because of the memory allocation:
0365             //the iterator has not been invalidated.
0366             index_type::erase(it);
0367             BOOST_RETHROW
0368          } BOOST_CATCH_END
0369       }
0370       return it;
0371    }
0372 };
0373
0374 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
0375
0376 //!Trait class to detect if an index is an intrusive
0377 //!index
0378 template<class MapConfig>
0379 struct is_intrusive_index
0380    <boost::interprocess::iunordered_set_index<MapConfig> >
0381 {
0382    static const bool value = true;
0383 };
0384 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
0385
0386 }}   //namespace boost { namespace interprocess {
0387
0388 #include <boost/interprocess/detail/config_end.hpp>
0389
0390 #endif   //#ifndef BOOST_INTERPROCESS_IUNORDERED_SET_INDEX_HPP