libstdc++-v3/include/profile/impl/profiler_algos.h

   1 // -*- C++ -*-
   2 //
   3 // Copyright (C) 2010-2019 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
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   9 // any later version.
  10 //
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  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
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  20 // You should have received a copy of the GNU General Public License along
  21 // with this library; see the file COPYING3.  If not see
  22 // <http://www.gnu.org/licenses/>.
  23
  24 /** @file profile/impl/profiler_algos.h
  25  *  @brief Algorithms used by the profile extension.
  26  *
  27  *  This file is needed to avoid including \<algorithm\> or \<bits/stl_algo.h\>.
  28  *  Including those files would result in recursive includes.
  29  *  These implementations are oversimplified.  In general, efficiency may be
  30  *  sacrificed to minimize maintenance overhead.
  31  */
  32
  33 #ifndef _GLIBCXX_PROFILE_PROFILER_ALGOS_H
  34 #define _GLIBCXX_PROFILE_PROFILER_ALGOS_H 1
  35
  36 namespace __gnu_profile
  37 {
  38   /* Helper for __top_n.  Insert in sorted vector, but not beyond Nth elem.  */
  39   template<typename _Container>
  40     void
  41     __insert_top_n(_Container& __output,
  42                    const typename _Container::value_type& __value,
  43                    typename _Container::size_type __n)
  44     {
  45       typename _Container::iterator __it = __output.begin();
  46       typename _Container::size_type __count = 0;
  47
  48       // Skip up to N - 1 elements larger than VALUE.
  49       // XXX: Could do binary search for random iterators.
  50       while (true)
  51         {
  52           if (__count >= __n)
  53             // VALUE is not in top N.
  54             return;
  55
  56           if (__it == __output.end())
  57             break;
  58
  59           if (*__it < __value)
  60             break;
  61
  62           ++__it;
  63           ++__count;
  64         }
  65
  66       __output.insert(__it, __value);
  67     }
  68
  69   /* Copy the top N elements in INPUT, sorted in reverse order, to OUTPUT.  */
  70   template<typename _Container>
  71     void
  72     __top_n(const _Container& __input, _Container& __output,
  73             typename _Container::size_type __n)
  74     {
  75       __output.clear();
  76       typename _Container::const_iterator __it;
  77       for (__it = __input.begin(); __it != __input.end(); ++__it)
  78         __insert_top_n(__output, *__it, __n);
  79     }
  80
  81   /* Simplified clone of std::for_each.  */
  82   template<typename _InputIterator, typename _Function>
  83     _Function
  84     __for_each(_InputIterator __first, _InputIterator __last, _Function __f)
  85     {
  86       for (; __first != __last; ++__first)
  87         __f(*__first);
  88       return __f;
  89     }
  90
  91   /* Simplified clone of std::remove.  */
  92   template<typename _ForwardIterator, typename _Tp>
  93     _ForwardIterator
  94     __remove(_ForwardIterator __first, _ForwardIterator __last,
  95              const _Tp& __value)
  96     {
  97       if(__first == __last)
  98         return __first;
  99       _ForwardIterator __result = __first;
 100       ++__first;
 101       for(; __first != __last; ++__first)
 102         if(!(*__first == __value))
 103           {
 104             *__result = *__first;
 105             ++__result;
 106           }
 107       return __result;
 108     }
 109 } // namespace __gnu_profile
 110
 111 #endif /* _GLIBCXX_PROFILE_PROFILER_ALGOS_H */