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Diffstat (limited to 'libstdc++-v3/include/ext/pb_ds/detail/binary_heap_/resize_policy.hpp')
| -rw-r--r-- | libstdc++-v3/include/ext/pb_ds/detail/binary_heap_/resize_policy.hpp | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/libstdc++-v3/include/ext/pb_ds/detail/binary_heap_/resize_policy.hpp b/libstdc++-v3/include/ext/pb_ds/detail/binary_heap_/resize_policy.hpp new file mode 100644 index 00000000000..1982e07ae74 --- /dev/null +++ b/libstdc++-v3/include/ext/pb_ds/detail/binary_heap_/resize_policy.hpp @@ -0,0 +1,295 @@ +// -*- C++ -*- + +// Copyright (C) 2005, 2006 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 2, 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. + +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING. If not, write to +// the Free Software Foundation, 59 Temple Place - Suite 330, Boston, +// MA 02111-1307, USA. + +// As a special exception, you may use this file as part of a free +// software library without restriction. Specifically, if other files +// instantiate templates or use macros or inline functions from this +// file, or you compile this file and link it with other files to +// produce an executable, this file does not by itself cause the +// resulting executable to be covered by the GNU General Public +// License. This exception does not however invalidate any other +// reasons why the executable file might be covered by the GNU General +// Public License. + +// 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 resize_policy.hpp + * Contains an implementation class for a binary_heap. + */ + +#ifndef PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP +#define PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP + +namespace pb_ds +{ + namespace detail + { + +#ifdef PB_DS_BINARY_HEAP_DEBUG_ +#define PB_DS_DBG_ASSERT(X) assert(X) +#define PB_DS_DBG_VERIFY(X) assert(X) +#define PB_DS_DBG_ONLY(X) X +#else // #ifdef PB_DS_BINARY_HEAP_DEBUG_ +#define PB_DS_DBG_ASSERT(X) +#define PB_DS_DBG_VERIFY(X) {if((X)==0);} +#define PB_DS_DBG_ONLY(X) ; +#endif // #ifdef PB_DS_BINARY_HEAP_DEBUG_ + +#define PB_DS_CLASS_T_DEC \ + template<typename Size_Type> + +#define PB_DS_CLASS_C_DEC \ + resize_policy< \ + Size_Type> + + template<typename Size_Type> + class resize_policy + { + public: + typedef Size_Type size_type; + + enum + { + min_size = 16 + }; + + public: + inline + resize_policy(); + + inline void + swap(PB_DS_CLASS_C_DEC& other); + + inline bool + resize_needed_for_grow(size_type size) const; + + inline bool + resize_needed_for_shrink(size_type size) const; + + inline bool + grow_needed(size_type size) const; + + inline bool + shrink_needed(size_type size) const; + + inline size_type + get_new_size_for_grow() const; + + inline size_type + get_new_size_for_shrink() const; + + size_type + get_new_size_for_arbitrary(size_type size) const; + + inline void + notify_grow_resize(); + + inline void + notify_shrink_resize(); + + void + notify_arbitrary(size_type actual_size); + +#ifdef PB_DS_BINARY_HEAP_DEBUG_ + void + assert_valid() const; +#endif // #ifdef PB_DS_BINARY_HEAP_DEBUG_ + +#ifdef PB_DS_BINARY_HEAP_TRACE_ + + void + trace() const; + +#endif // #ifdef PB_DS_BINARY_HEAP_TRACE_ + + private: + enum + { + ratio = 8, + factor = 2 + }; + + private: + size_type m_next_shrink_size; + + size_type m_next_grow_size; + }; + + PB_DS_CLASS_T_DEC + inline + PB_DS_CLASS_C_DEC:: + resize_policy() : + m_next_shrink_size(0), + m_next_grow_size(min_size) + { + PB_DS_DBG_ONLY(assert_valid();) + } + + PB_DS_CLASS_T_DEC + inline void + PB_DS_CLASS_C_DEC:: + swap(PB_DS_CLASS_C_DEC& other) + { + std::swap(m_next_shrink_size, other.m_next_shrink_size); + std::swap(m_next_grow_size, other.m_next_grow_size); + } + + PB_DS_CLASS_T_DEC + inline bool + PB_DS_CLASS_C_DEC:: + resize_needed_for_grow(size_type size) const + { + PB_DS_DBG_ASSERT(size <= m_next_grow_size); + + return size == m_next_grow_size; + } + + PB_DS_CLASS_T_DEC + inline bool + PB_DS_CLASS_C_DEC:: + resize_needed_for_shrink(size_type size) const + { + PB_DS_DBG_ASSERT(size <= m_next_grow_size); + + return size == m_next_shrink_size; + } + + PB_DS_CLASS_T_DEC + inline typename PB_DS_CLASS_C_DEC::size_type + PB_DS_CLASS_C_DEC:: + get_new_size_for_grow() const + { + return m_next_grow_size* factor; + } + + PB_DS_CLASS_T_DEC + inline typename PB_DS_CLASS_C_DEC::size_type + PB_DS_CLASS_C_DEC:: + get_new_size_for_shrink() const + { + const size_type half_size = m_next_grow_size / factor; + + return std::max(static_cast<size_type>(min_size), half_size); + } + + PB_DS_CLASS_T_DEC + inline typename PB_DS_CLASS_C_DEC::size_type + PB_DS_CLASS_C_DEC:: + get_new_size_for_arbitrary(size_type size) const + { + size_type ret = min_size; + + while (ret < size) + ret *= factor; + + return ret; + } + + PB_DS_CLASS_T_DEC + inline void + PB_DS_CLASS_C_DEC:: + notify_grow_resize() + { + PB_DS_DBG_ONLY(assert_valid();) + + PB_DS_DBG_ASSERT(m_next_grow_size >= min_size); + + m_next_grow_size *= factor; + + m_next_shrink_size = m_next_grow_size / ratio; + + PB_DS_DBG_ONLY(assert_valid();) + } + + PB_DS_CLASS_T_DEC + inline void + PB_DS_CLASS_C_DEC:: + notify_shrink_resize() + { + PB_DS_DBG_ONLY(assert_valid();) + + m_next_shrink_size /= factor; + if (m_next_shrink_size == 1) + m_next_shrink_size = 0; + + m_next_grow_size = + std::max(m_next_grow_size / factor, static_cast<size_type>(min_size)); + + PB_DS_DBG_ONLY(assert_valid();) + } + + PB_DS_CLASS_T_DEC + inline void + PB_DS_CLASS_C_DEC:: + notify_arbitrary(size_type actual_size) + { + m_next_grow_size = actual_size; + + m_next_shrink_size = m_next_grow_size / ratio; + + PB_DS_DBG_ONLY(assert_valid();) + } + +#ifdef PB_DS_BINARY_HEAP_DEBUG_ + PB_DS_CLASS_T_DEC + void + PB_DS_CLASS_C_DEC:: + assert_valid() const + { + PB_DS_DBG_ASSERT(m_next_shrink_size == 0 || + m_next_shrink_size* ratio == m_next_grow_size); + + PB_DS_DBG_ASSERT(m_next_grow_size >= min_size); + } +#endif // #ifdef PB_DS_BINARY_HEAP_DEBUG_ + +#ifdef PB_DS_BINARY_HEAP_TRACE_ + PB_DS_CLASS_T_DEC + void + PB_DS_CLASS_C_DEC:: + trace() const + { + std::cerr << "shrink = " << m_next_shrink_size << + " grow = " << m_next_grow_size << std::endl; + } +#endif // #ifdef PB_DS_BINARY_HEAP_TRACE_ + +#undef PB_DS_CLASS_T_DEC + +#undef PB_DS_CLASS_C_DEC + +#undef PB_DS_DBG_ASSERT +#undef PB_DS_DBG_VERIFY +#undef PB_DS_DBG_ONLY + + } // namespace detail +} // namespace pb_ds + +#endif // #ifndef PB_DS_BINARY_HEAP_RESIZE_POLICY_HPP |