Aqui está a situação que estou tentando simular:

  COL1                 Col2     Col3
CBT.151.5.T.FEED       S1       t1
CBT.151.5.T.FEED       s2       t2
CBT.151.5.T.FEED       s3       t3
CBT.151.5.T.FEED       s4       t4
CBT.151.5.T.FEED       s5       t1

CBT.151.8.T.FEED       s7       t1
CBT.151.5.Q.FEED       s8       t3

COL1 - é o ID, para um determinado ID pode haver vários símbolos.
COL2 - símbolos, eles são únicos
COL3 - hora da atualização de um símbolo, dois símbolos diferentes podem ser atualizados ao mesmo tempo, portanto, não são exclusivos.

Meu objetivo é obter os tickers mais ativos, digamos os símbolos que foram atualizados nos últimos 60 segundos. Para esse fim, usei o multi-index boost.

O arquivo de cabeçalho:

#ifndef __TICKER_INFO_MANAGER_IMPL__
#define __TICKER_INFO_MANAGER_IMPL__

#include <boost/interprocess/containers/string.hpp>
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/member.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <TickerInfoManagerConstants.h>
#include <TickerInfo.h>

namespace bmi = boost::multi_index;
namespace bip = boost::interprocess;

struct id_index{};
struct symbol_index{};
struct last_update_time_index{};

struct Less {
  template<class T, class U>
    bool operator()(T const& t, U const& u) const {
      return t < u;
    }
};


typedef bmi::multi_index_container<
tickerUpdateInfoT,
  bmi::indexed_by<
  bmi::ordered_unique
  <bmi::tag<id_index>,  BOOST_MULTI_INDEX_MEMBER( tickerUpdateInfo, shm_string, m_id), Less>,
  bmi::ordered_unique<
  bmi::tag<symbol_index>,BOOST_MULTI_INDEX_MEMBER(tickerUpdateInfo, shm_string, m_symbol), Less>,
  bmi::ordered_non_unique
  <bmi::tag<last_update_time_index>, BOOST_MULTI_INDEX_MEMBER(tickerUpdateInfo, int, m_last_update_time), Less> >,
  bip::managed_shared_memory::allocator<tickerUpdateInfo>::type
  > ticker_update_info_set;

  class tickerInfoMangerImplementation {

    public:
      tickerInfoMangerImplementation( const sharedMemoryNameT & name );

      bool put_records( const tickerUpdateInfoT & record );

      int get_active_ticker_count( const thresholdT seconds );

      void print_contents();

      bip::managed_shared_memory& get_managed_memory_segment() {
        return m_managed_memory_segment;
      }

    private:
      const sharedMemoryNameT    m_name;
      bip::managed_shared_memory m_managed_memory_segment;
      ticker_update_info_set     *p_ticker_info_set;
  };
#endif

O arquivo cpp

#include <TickerInfoMangerImplementation.h>
#include <boost/interprocess/managed_shared_memory.hpp>
#include <iostream>
#include "basic_time.h"

using namespace boost::interprocess;

tickerInfoMangerImplementation::tickerInfoMangerImplementation( const sharedMemoryNameT & name ): m_name(name),
  m_managed_memory_segment( open_or_create, "test", 65536 )
{

  p_ticker_info_set = m_managed_memory_segment.find_or_construct<ticker_update_info_set>
    ("SetOfTickerUpdateInformation")            //Container's name in shared memory
    ( ticker_update_info_set::ctor_args_list()
      , m_managed_memory_segment.get_allocator<tickerUpdateInfoT>());  //Ctor parameters
}

bool tickerInfoMangerImplementation::put_records( const tickerUpdateInfoT & record ) {

  std::pair<ticker_update_info_set::iterator, bool> result_pair = p_ticker_info_set->insert( record );
  if( result_pair.second ) {
    return result_pair.second;
  }

  typedef ticker_update_info_set::index<symbol_index>::type ticker_update_info_set_by_symbol;

  ticker_update_info_set_by_symbol & sym_index = (*p_ticker_info_set).get<symbol_index>();
  ticker_update_info_set_by_symbol::iterator it = sym_index.find( record.m_symbol );
  tickerUpdateInfoT ticker_info = *it;
  ticker_info.m_last_update_time = record.m_last_update_time;
  return sym_index.replace( it, ticker_info );
}

int tickerInfoMangerImplementation::calculate_historical_time_using_threshold( const thresholdT seconds ) {

  basic_time::Secs_t seconds( threshold );
  basic_time tick_time;
  tick_time -= seconds;
  return ( tick_time.fullTime() );
}

int tickerInfoMangerImplementation::get_active_ticker_count( const thresholdT seconds, std::string key ) {

  typedef ticker_update_info_set::index<id_index>::type ticker_update_info_set_by_id;
  ticker_update_info_set_by_id & id_index = (*p_ticker_info_set).get<id_index>();
  int tick_time = calculate_historical_time_using_threshold( seconds );
  //Here I would like to find the key
  //Based on that key I would like to fetch all the symbols which have updated after a certain time(using lower bound)
  std::copy( it, time_index.end(), std::ostream_iterator<tickerUpdateInfoT>(std::cout) );
}


void tickerInfoMangerImplementation::print_contents() {
  const ticker_update_info_set::nth_index<1>::type& name_index = (*p_ticker_info_set).get<1>();
  std::copy( name_index.begin(), name_index.end(), std::ostream_iterator<tickerUpdateInfoT>(std::cout) );
}

std::ostream& operator<<(std::ostream& os, const tickerUpdateInfoT & obj) {
  os << obj.m_id << " ";
  os << obj.m_symbol << " ";
  os << obj.m_last_update_time << " " << "\n";
  return os;
};

Estrutura de um registro que eu inseriria no multi-índice de impulso

#ifndef __TICKER_INFO__
#define __TICKER_INFO__

#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/containers/string.hpp>

typedef boost::interprocess::managed_shared_memory::allocator<char>::type               char_allocator;
typedef boost::interprocess::basic_string<char, std::char_traits<char>, char_allocator> shm_string;

//Data to insert in shared memory
typedef struct tickerUpdateInfo {

  shm_string  m_id;
  shm_string  m_symbol;
  int         m_last_update_time;

  tickerUpdateInfo( const char * id,
      const char *symbol,
      int last_update_time,
      const char_allocator &a)
    : m_id( id, a), m_symbol( symbol, a), m_last_update_time( last_update_time) {
    }

  tickerUpdateInfo& operator=(const tickerUpdateInfo& other) {
   if (this != &other) {
       m_last_update_time = other.m_last_update_time;
      }
    return *this;
  }
} tickerUpdateInfoT;

#endif

Agora, na função get_active_ticker_count (), quero especificar a chave como CBT.151.5.T.FEED e ela deve retornar:

   S1       t1
   s2       t2
   s3       t3
   s4       t4
   s5       t1

Vamos assumir t1> t2> t3> t4, então eu gostaria de descobrir esses conjuntos em que os tempos são maiores que t3 e também quero encontrar a contagem desses símbolos. Como procedo da mesma forma, consegui inserir, mas estou preso à parte de recuperação. Por favor ajude!