--- /dev/null
+// -*- C++ -*-
+
+// Copyright (C) 2005, 2006, 2009, 2011 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 binary_heap_/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
+
+#include <debug/debug.h>
+
+namespace __gnu_pbds
+{
+ namespace detail
+ {
+ /// Resize policy for binary heap.
+ template<typename _Tp>
+ class resize_policy
+ {
+ private:
+ enum
+ {
+ ratio = 8,
+ factor = 2
+ };
+
+ /// Next shrink size.
+ _Tp m_shrink_size;
+
+ /// Next grow size.
+ _Tp m_grow_size;
+
+ public:
+ typedef _Tp size_type;
+
+ static const _Tp min_size = 16;
+
+ resize_policy() : m_shrink_size(0), m_grow_size(min_size)
+ { PB_DS_ASSERT_VALID((*this)) }
+
+ resize_policy(const resize_policy& other)
+ : m_shrink_size(other.m_shrink_size), m_grow_size(other.m_grow_size)
+ { PB_DS_ASSERT_VALID((*this)) }
+
+ inline void
+ swap(resize_policy<_Tp>&);
+
+ inline bool
+ resize_needed_for_grow(size_type) const;
+
+ inline bool
+ resize_needed_for_shrink(size_type) const;
+
+ inline bool
+ grow_needed(size_type) const;
+
+ inline bool
+ shrink_needed(size_type) const;
+
+ inline size_type
+ get_new_size_for_grow() const;
+
+ inline size_type
+ get_new_size_for_shrink() const;
+
+ inline size_type
+ get_new_size_for_arbitrary(size_type) const;
+
+ inline void
+ notify_grow_resize();
+
+ inline void
+ notify_shrink_resize();
+
+ void
+ notify_arbitrary(size_type);
+
+#ifdef _GLIBCXX_DEBUG
+ void
+ assert_valid(const char*, int) const;
+#endif
+
+#ifdef PB_DS_BINARY_HEAP_TRACE_
+ void
+ trace() const;
+#endif
+ };
+
+ template<typename _Tp>
+ const _Tp resize_policy<_Tp>::min_size;
+
+ template<typename _Tp>
+ inline void
+ resize_policy<_Tp>::
+ swap(resize_policy<_Tp>& other)
+ {
+ std::swap(m_shrink_size, other.m_shrink_size);
+ std::swap(m_grow_size, other.m_grow_size);
+ }
+
+ template<typename _Tp>
+ inline bool
+ resize_policy<_Tp>::
+ resize_needed_for_grow(size_type size) const
+ {
+ _GLIBCXX_DEBUG_ASSERT(size <= m_grow_size);
+ return size == m_grow_size;
+ }
+
+ template<typename _Tp>
+ inline bool
+ resize_policy<_Tp>::
+ resize_needed_for_shrink(size_type size) const
+ {
+ _GLIBCXX_DEBUG_ASSERT(size <= m_grow_size);
+ return size == m_shrink_size;
+ }
+
+ template<typename _Tp>
+ inline typename resize_policy<_Tp>::size_type
+ resize_policy<_Tp>::
+ get_new_size_for_grow() const
+ { return m_grow_size * factor; }
+
+ template<typename _Tp>
+ inline typename resize_policy<_Tp>::size_type
+ resize_policy<_Tp>::
+ get_new_size_for_shrink() const
+ {
+ const size_type half_size = m_grow_size / factor;
+ return std::max(min_size, half_size);
+ }
+
+ template<typename _Tp>
+ inline typename resize_policy<_Tp>::size_type
+ resize_policy<_Tp>::
+ get_new_size_for_arbitrary(size_type size) const
+ {
+ size_type ret = min_size;
+ while (ret < size)
+ ret *= factor;
+ return ret;
+ }
+
+ template<typename _Tp>
+ inline void
+ resize_policy<_Tp>::
+ notify_grow_resize()
+ {
+ PB_DS_ASSERT_VALID((*this))
+ _GLIBCXX_DEBUG_ASSERT(m_grow_size >= min_size);
+ m_grow_size *= factor;
+ m_shrink_size = m_grow_size / ratio;
+ PB_DS_ASSERT_VALID((*this))
+ }
+
+ template<typename _Tp>
+ inline void
+ resize_policy<_Tp>::
+ notify_shrink_resize()
+ {
+ PB_DS_ASSERT_VALID((*this))
+ m_shrink_size /= factor;
+ if (m_shrink_size == 1)
+ m_shrink_size = 0;
+ m_grow_size = std::max(m_grow_size / factor, min_size);
+ PB_DS_ASSERT_VALID((*this))
+ }
+
+ template<typename _Tp>
+ inline void
+ resize_policy<_Tp>::
+ notify_arbitrary(size_type actual_size)
+ {
+ m_grow_size = actual_size;
+ m_shrink_size = m_grow_size / ratio;
+ PB_DS_ASSERT_VALID((*this))
+ }
+
+#ifdef _GLIBCXX_DEBUG
+ template<typename _Tp>
+ void
+ resize_policy<_Tp>::
+ assert_valid(const char* __file, int __line) const
+ {
+ PB_DS_DEBUG_VERIFY(m_shrink_size == 0
+ || m_shrink_size * ratio == m_grow_size);
+ PB_DS_DEBUG_VERIFY(m_grow_size >= min_size);
+ }
+#endif
+
+#ifdef PB_DS_BINARY_HEAP_TRACE_
+ template<typename _Tp>
+ void
+ resize_policy<_Tp>::
+ trace() const
+ {
+ std::cerr << "shrink = " << m_shrink_size
+ << " grow = " << m_grow_size << std::endl;
+ }
+#endif
+
+} // namespace detail
+} // namespace __gnu_pbds
+
+#endif
projects / cross.git / blobdiff