hash_load_check_resize_trigger_imp.hpp
Go to the documentation of this file.
// -*- C++ -*-
// Copyright (C) 2005-2016 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
// Permission to use, copy, modify, sell, and distribute this software
// is hereby granted without fee, provided that the above copyright
// notice appears in all copies, and that both that copyright notice
// and this permission notice appear in supporting documentation. None
// of the above authors, nor IBM Haifa Research Laboratories, make any
// representation about the suitability of this software for any
// purpose. It is provided "as is" without express or implied
// warranty.
/**
* @file hash_load_check_resize_trigger_imp.hpp
* Contains a resize trigger implementation.
*/
#define PB_DS_ASSERT_VALID(X) \
_GLIBCXX_DEBUG_ONLY(X.assert_valid(__FILE__, __LINE__);)
PB_DS_CLASS_T_DEC
PB_DS_CLASS_C_DEC::
hash_load_check_resize_trigger(float load_min, float load_max)
: m_load_min(load_min), m_load_max(load_max), m_next_shrink_size(0),
m_next_grow_size(0), m_resize_needed(false)
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_find_search_start()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_find_search_collision()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_find_search_end()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_insert_search_start()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_insert_search_collision()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_insert_search_end()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_erase_search_start()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_erase_search_collision()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_erase_search_end()
{ PB_DS_ASSERT_VALID((*this)) }
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_inserted(size_type num_entries)
{
m_resize_needed = (num_entries >= m_next_grow_size);
size_base::set_size(num_entries);
PB_DS_ASSERT_VALID((*this))
}
PB_DS_CLASS_T_DEC
inline void
PB_DS_CLASS_C_DEC::
notify_erased(size_type num_entries)
{
size_base::set_size(num_entries);
m_resize_needed = num_entries <= m_next_shrink_size;
PB_DS_ASSERT_VALID((*this))
}
PB_DS_CLASS_T_DEC
inline bool
PB_DS_CLASS_C_DEC::
is_resize_needed() const
{
PB_DS_ASSERT_VALID((*this))
return m_resize_needed;
}
PB_DS_CLASS_T_DEC
inline bool
PB_DS_CLASS_C_DEC::
is_grow_needed(size_type /*size*/, size_type num_entries) const
{
_GLIBCXX_DEBUG_ASSERT(m_resize_needed);
return num_entries >= m_next_grow_size;
}
PB_DS_CLASS_T_DEC
PB_DS_CLASS_C_DEC::
~hash_load_check_resize_trigger() { }
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
notify_resized(size_type new_size)
{
m_resize_needed = false;
m_next_grow_size = size_type(m_load_max * new_size - 1);
m_next_shrink_size = size_type(m_load_min * new_size);
#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
std::cerr << "hlcrt::notify_resized " << std::endl
<< "1 " << new_size << std::endl
<< "2 " << m_load_min << std::endl
<< "3 " << m_load_max << std::endl
<< "4 " << m_next_shrink_size << std::endl
<< "5 " << m_next_grow_size << std::endl;
#endif
PB_DS_ASSERT_VALID((*this))
}
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
notify_externally_resized(size_type new_size)
{
m_resize_needed = false;
size_type new_grow_size = size_type(m_load_max * new_size - 1);
size_type new_shrink_size = size_type(m_load_min * new_size);
#ifdef PB_DS_HT_MAP_RESIZE_TRACE_
std::cerr << "hlcrt::notify_externally_resized " << std::endl
<< "1 " << new_size << std::endl
<< "2 " << m_load_min << std::endl
<< "3 " << m_load_max << std::endl
<< "4 " << m_next_shrink_size << std::endl
<< "5 " << m_next_grow_size << std::endl
<< "6 " << new_shrink_size << std::endl
<< "7 " << new_grow_size << std::endl;
#endif
if (new_grow_size >= m_next_grow_size)
{
_GLIBCXX_DEBUG_ASSERT(new_shrink_size >= m_next_shrink_size);
m_next_grow_size = new_grow_size;
}
else
{
_GLIBCXX_DEBUG_ASSERT(new_shrink_size <= m_next_shrink_size);
m_next_shrink_size = new_shrink_size;
}
PB_DS_ASSERT_VALID((*this))
}
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
notify_cleared()
{
PB_DS_ASSERT_VALID((*this))
size_base::set_size(0);
m_resize_needed = (0 < m_next_shrink_size);
PB_DS_ASSERT_VALID((*this))
}
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
swap(PB_DS_CLASS_C_DEC& other)
{
PB_DS_ASSERT_VALID((*this))
PB_DS_ASSERT_VALID(other)
size_base::swap(other);
std::swap(m_load_min, other.m_load_min);
std::swap(m_load_max, other.m_load_max);
std::swap(m_resize_needed, other.m_resize_needed);
std::swap(m_next_grow_size, other.m_next_grow_size);
std::swap(m_next_shrink_size, other.m_next_shrink_size);
PB_DS_ASSERT_VALID((*this))
PB_DS_ASSERT_VALID(other)
}
PB_DS_CLASS_T_DEC
inline std::pair<float, float>
PB_DS_CLASS_C_DEC::
get_loads() const
{
PB_DS_STATIC_ASSERT(access, external_load_access);
return std::make_pair(m_load_min, m_load_max);
}
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
set_loads(std::pair<float, float> load_pair)
{
PB_DS_STATIC_ASSERT(access, external_load_access);
const float old_load_min = m_load_min;
const float old_load_max = m_load_max;
const size_type old_next_shrink_size = m_next_shrink_size;
const size_type old_next_grow_size = m_next_grow_size;
const bool old_resize_needed = m_resize_needed;
__try
{
m_load_min = load_pair.first;
m_load_max = load_pair.second;
do_resize(static_cast<size_type>(size_base::get_size() / ((m_load_min + m_load_max) / 2)));
}
__catch(...)
{
m_load_min = old_load_min;
m_load_max = old_load_max;
m_next_shrink_size = old_next_shrink_size;
m_next_grow_size = old_next_grow_size;
m_resize_needed = old_resize_needed;
__throw_exception_again;
}
}
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
do_resize(size_type)
{ std::abort(); }
#ifdef _GLIBCXX_DEBUG
# define PB_DS_DEBUG_VERIFY(_Cond) \
_GLIBCXX_DEBUG_VERIFY_AT(_Cond, \
_M_message(#_Cond" assertion from %1;:%2;") \
._M_string(__FILE__)._M_integer(__LINE__) \
,__file,__line)
PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
assert_valid(const char* __file, int __line) const
{
PB_DS_DEBUG_VERIFY(m_load_max > m_load_min);
PB_DS_DEBUG_VERIFY(m_next_grow_size >= m_next_shrink_size);
}
# undef PB_DS_DEBUG_VERIFY
#endif
#undef PB_DS_ASSERT_VALID
std::cerr
ostream cerr
Linked to standard output.
std::endl
basic_ostream< _CharT, _Traits > & endl(basic_ostream< _CharT, _Traits > &__os)
Write a newline and flush the stream.
Definition: ostream:590
std::pair::first
_T1 first
second_type is the second bound type
Definition: stl_pair.h:199
std
ISO C++ entities toplevel namespace is std.
std::make_pair
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition: stl_pair.h:497
std::pair
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:194
std::pair::second
_T2 second
first is a copy of the first object
Definition: stl_pair.h:200