forked from boostorg/unordered
c680fa7418
FWIW the standard says that equality is undefined behaviour if the Hash and Pred function objects behave differently. But I think we should support different hash functions, e.g. so that randomized hash functions will work.
797 lines
24 KiB
C++
797 lines
24 KiB
C++
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// Copyright (C) 2003-2004 Jeremy B. Maitin-Shepard.
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// Copyright (C) 2005-2011 Daniel James
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_UNORDERED_DETAIL_ALL_HPP_INCLUDED
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#define BOOST_UNORDERED_DETAIL_ALL_HPP_INCLUDED
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#include <boost/config.hpp>
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#if defined(BOOST_HAS_PRAGMA_ONCE)
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#pragma once
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#endif
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#include <boost/unordered/detail/buckets.hpp>
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#if defined(BOOST_MSVC)
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#pragma warning(push)
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#pragma warning(disable:4127) // conditional expression is constant
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#endif
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namespace boost { namespace unordered { namespace detail {
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////////////////////////////////////////////////////////////////////////////
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// convert double to std::size_t
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inline std::size_t double_to_size(double f)
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{
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return f >= static_cast<double>(
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(std::numeric_limits<std::size_t>::max)()) ?
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(std::numeric_limits<std::size_t>::max)() :
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static_cast<std::size_t>(f);
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}
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// The space used to store values in a node.
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template <typename ValueType>
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struct value_base
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{
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typedef ValueType value_type;
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typename boost::aligned_storage<
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sizeof(value_type),
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boost::alignment_of<value_type>::value>::type data_;
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value_base() :
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data_()
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{}
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void* address() {
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return this;
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}
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value_type& value() {
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return *(ValueType*) this;
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}
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value_type* value_ptr() {
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return (ValueType*) this;
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}
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private:
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value_base& operator=(value_base const&);
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};
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template <typename Types>
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struct table :
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boost::unordered::detail::functions<
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typename Types::hasher,
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typename Types::key_equal>
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{
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private:
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table(table const&);
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table& operator=(table const&);
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public:
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typedef typename Types::node node;
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typedef typename Types::bucket bucket;
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typedef typename Types::hasher hasher;
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typedef typename Types::key_equal key_equal;
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typedef typename Types::key_type key_type;
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typedef typename Types::extractor extractor;
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typedef typename Types::value_type value_type;
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typedef typename Types::table table_impl;
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typedef typename Types::link_pointer link_pointer;
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typedef typename Types::policy policy;
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typedef boost::unordered::detail::functions<
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typename Types::hasher,
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typename Types::key_equal> functions;
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typedef typename functions::set_hash_functions set_hash_functions;
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typedef typename Types::allocator allocator;
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typedef typename boost::unordered::detail::
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rebind_wrap<allocator, node>::type node_allocator;
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typedef typename boost::unordered::detail::
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rebind_wrap<allocator, bucket>::type bucket_allocator;
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typedef boost::unordered::detail::allocator_traits<node_allocator>
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node_allocator_traits;
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typedef boost::unordered::detail::allocator_traits<bucket_allocator>
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bucket_allocator_traits;
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typedef typename node_allocator_traits::pointer
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node_pointer;
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typedef typename node_allocator_traits::const_pointer
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const_node_pointer;
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typedef typename bucket_allocator_traits::pointer
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bucket_pointer;
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typedef boost::unordered::detail::node_constructor<node_allocator>
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node_constructor;
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typedef boost::unordered::detail::node_tmp<node_allocator>
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node_tmp;
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typedef boost::unordered::iterator_detail::
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iterator<node> iterator;
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typedef boost::unordered::iterator_detail::
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c_iterator<node> c_iterator;
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typedef boost::unordered::iterator_detail::
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l_iterator<node, policy> l_iterator;
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typedef boost::unordered::iterator_detail::
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cl_iterator<node, policy> cl_iterator;
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////////////////////////////////////////////////////////////////////////
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// Members
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boost::unordered::detail::compressed<bucket_allocator, node_allocator>
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allocators_;
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std::size_t bucket_count_;
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std::size_t size_;
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float mlf_;
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std::size_t max_load_;
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bucket_pointer buckets_;
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////////////////////////////////////////////////////////////////////////
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// Node functions
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static inline node_pointer next_node(link_pointer n) {
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return static_cast<node_pointer>(n->next_);
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}
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////////////////////////////////////////////////////////////////////////
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// Data access
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bucket_allocator const& bucket_alloc() const
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{
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return allocators_.first();
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}
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node_allocator const& node_alloc() const
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{
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return allocators_.second();
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}
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bucket_allocator& bucket_alloc()
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{
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return allocators_.first();
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}
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node_allocator& node_alloc()
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{
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return allocators_.second();
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}
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std::size_t max_bucket_count() const
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{
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// -1 to account for the start bucket.
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return policy::prev_bucket_count(
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bucket_allocator_traits::max_size(bucket_alloc()) - 1);
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}
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bucket_pointer get_bucket(std::size_t bucket_index) const
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{
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BOOST_ASSERT(buckets_);
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return buckets_ + static_cast<std::ptrdiff_t>(bucket_index);
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}
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link_pointer get_previous_start() const
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{
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return get_bucket(bucket_count_)->first_from_start();
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}
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link_pointer get_previous_start(std::size_t bucket_index) const
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{
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return get_bucket(bucket_index)->next_;
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}
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node_pointer begin() const
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{
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return size_ ? next_node(get_previous_start()) : node_pointer();
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}
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node_pointer begin(std::size_t bucket_index) const
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{
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if (!size_) return node_pointer();
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link_pointer prev = get_previous_start(bucket_index);
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return prev ? next_node(prev) : node_pointer();
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}
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std::size_t hash_to_bucket(std::size_t hash_value) const
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{
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return policy::to_bucket(bucket_count_, hash_value);
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}
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float load_factor() const
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{
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BOOST_ASSERT(bucket_count_ != 0);
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return static_cast<float>(size_)
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/ static_cast<float>(bucket_count_);
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}
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std::size_t bucket_size(std::size_t index) const
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{
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node_pointer n = begin(index);
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if (!n) return 0;
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std::size_t count = 0;
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while(n && hash_to_bucket(n->hash_) == index)
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{
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++count;
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n = next_node(n);
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}
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return count;
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}
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////////////////////////////////////////////////////////////////////////
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// Load methods
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std::size_t max_size() const
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{
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using namespace std;
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// size < mlf_ * count
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return boost::unordered::detail::double_to_size(ceil(
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static_cast<double>(mlf_) *
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static_cast<double>(max_bucket_count())
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)) - 1;
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}
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void recalculate_max_load()
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{
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using namespace std;
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// From 6.3.1/13:
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// Only resize when size >= mlf_ * count
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max_load_ = buckets_ ? boost::unordered::detail::double_to_size(ceil(
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static_cast<double>(mlf_) *
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static_cast<double>(bucket_count_)
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)) : 0;
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}
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void max_load_factor(float z)
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{
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BOOST_ASSERT(z > 0);
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mlf_ = (std::max)(z, minimum_max_load_factor);
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recalculate_max_load();
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}
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std::size_t min_buckets_for_size(std::size_t size) const
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{
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BOOST_ASSERT(mlf_ >= minimum_max_load_factor);
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using namespace std;
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// From 6.3.1/13:
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// size < mlf_ * count
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// => count > size / mlf_
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//
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// Or from rehash post-condition:
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// count > size / mlf_
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return policy::new_bucket_count(
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boost::unordered::detail::double_to_size(floor(
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static_cast<double>(size) /
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static_cast<double>(mlf_)) + 1));
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}
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////////////////////////////////////////////////////////////////////////
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// Constructors
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table(std::size_t num_buckets,
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hasher const& hf,
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key_equal const& eq,
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node_allocator const& a) :
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functions(hf, eq),
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allocators_(a,a),
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bucket_count_(policy::new_bucket_count(num_buckets)),
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size_(0),
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mlf_(1.0f),
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max_load_(0),
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buckets_()
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{}
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table(table const& x, node_allocator const& a) :
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functions(x),
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allocators_(a,a),
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bucket_count_(x.min_buckets_for_size(x.size_)),
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size_(0),
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mlf_(x.mlf_),
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max_load_(0),
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buckets_()
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{}
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table(table& x, boost::unordered::detail::move_tag m) :
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functions(x, m),
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allocators_(x.allocators_, m),
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bucket_count_(x.bucket_count_),
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size_(x.size_),
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mlf_(x.mlf_),
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max_load_(x.max_load_),
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buckets_(x.buckets_)
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{
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x.buckets_ = bucket_pointer();
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x.size_ = 0;
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x.max_load_ = 0;
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}
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table(table& x, node_allocator const& a,
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boost::unordered::detail::move_tag m) :
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functions(x, m),
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allocators_(a, a),
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bucket_count_(x.bucket_count_),
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size_(0),
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mlf_(x.mlf_),
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max_load_(x.max_load_),
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buckets_()
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{}
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////////////////////////////////////////////////////////////////////////
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// Initialisation.
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void init(table const& x)
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{
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if (x.size_) {
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static_cast<table_impl*>(this)->copy_buckets(x);
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}
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}
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void move_init(table& x)
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{
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if(node_alloc() == x.node_alloc()) {
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move_buckets_from(x);
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}
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else if(x.size_) {
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// TODO: Could pick new bucket size?
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static_cast<table_impl*>(this)->move_buckets(x);
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}
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}
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////////////////////////////////////////////////////////////////////////
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// Create buckets
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void create_buckets(std::size_t new_count)
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{
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std::size_t length = new_count + 1;
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bucket_pointer new_buckets = bucket_allocator_traits::allocate(
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bucket_alloc(), length);
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bucket_pointer constructed = new_buckets;
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BOOST_TRY {
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bucket_pointer end = new_buckets
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+ static_cast<std::ptrdiff_t>(length);
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for(; constructed != end; ++constructed) {
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new ((void*) boost::addressof(*constructed)) bucket();
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}
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if (buckets_)
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{
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// Copy the nodes to the new buckets, including the dummy
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// node if there is one.
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(new_buckets +
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static_cast<std::ptrdiff_t>(new_count))->next_ =
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(buckets_ + static_cast<std::ptrdiff_t>(
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bucket_count_))->next_;
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destroy_buckets();
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}
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else if (bucket::extra_node)
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{
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node_constructor a(node_alloc());
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a.create_node();
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(new_buckets +
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static_cast<std::ptrdiff_t>(new_count))->next_ =
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a.release();
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}
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}
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BOOST_CATCH(...) {
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for(bucket_pointer p = new_buckets; p != constructed; ++p) {
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boost::unordered::detail::func::destroy(
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boost::addressof(*p));
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}
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bucket_allocator_traits::deallocate(bucket_alloc(),
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new_buckets, length);
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BOOST_RETHROW;
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}
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BOOST_CATCH_END
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bucket_count_ = new_count;
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buckets_ = new_buckets;
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recalculate_max_load();
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}
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////////////////////////////////////////////////////////////////////////
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// Swap and Move
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void swap_allocators(table& other, false_type)
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{
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boost::unordered::detail::func::ignore_unused_variable_warning(other);
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// According to 23.2.1.8, if propagate_on_container_swap is
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// false the behaviour is undefined unless the allocators
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// are equal.
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BOOST_ASSERT(node_alloc() == other.node_alloc());
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}
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void swap_allocators(table& other, true_type)
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{
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allocators_.swap(other.allocators_);
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}
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// Only swaps the allocators if propagate_on_container_swap
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void swap(table& x)
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{
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set_hash_functions op1(*this, x);
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set_hash_functions op2(x, *this);
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// I think swap can throw if Propagate::value,
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// since the allocators' swap can throw. Not sure though.
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swap_allocators(x,
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boost::unordered::detail::integral_constant<bool,
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allocator_traits<node_allocator>::
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propagate_on_container_swap::value>());
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boost::swap(buckets_, x.buckets_);
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boost::swap(bucket_count_, x.bucket_count_);
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boost::swap(size_, x.size_);
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std::swap(mlf_, x.mlf_);
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std::swap(max_load_, x.max_load_);
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op1.commit();
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op2.commit();
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}
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// Only call with nodes allocated with the currect allocator, or
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// one that is equal to it. (Can't assert because other's
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// allocators might have already been moved).
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void move_buckets_from(table& other)
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{
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BOOST_ASSERT(!buckets_);
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buckets_ = other.buckets_;
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bucket_count_ = other.bucket_count_;
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size_ = other.size_;
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other.buckets_ = bucket_pointer();
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other.size_ = 0;
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other.max_load_ = 0;
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}
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////////////////////////////////////////////////////////////////////////
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// Delete/destruct
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~table()
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{
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delete_buckets();
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}
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void delete_node(link_pointer prev)
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{
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node_pointer n = static_cast<node_pointer>(prev->next_);
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prev->next_ = n->next_;
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boost::unordered::detail::func::destroy_value_impl(node_alloc(),
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n->value_ptr());
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boost::unordered::detail::func::destroy(boost::addressof(*n));
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node_allocator_traits::deallocate(node_alloc(), n, 1);
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--size_;
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}
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std::size_t delete_nodes(link_pointer prev, link_pointer end)
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{
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BOOST_ASSERT(prev->next_ != end);
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std::size_t count = 0;
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do {
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delete_node(prev);
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++count;
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} while (prev->next_ != end);
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return count;
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}
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void delete_buckets()
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{
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if(buckets_) {
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if (size_) delete_nodes(get_previous_start(), link_pointer());
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if (bucket::extra_node) {
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node_pointer n = static_cast<node_pointer>(
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get_bucket(bucket_count_)->next_);
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boost::unordered::detail::func::destroy(
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boost::addressof(*n));
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node_allocator_traits::deallocate(node_alloc(), n, 1);
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}
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destroy_buckets();
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buckets_ = bucket_pointer();
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max_load_ = 0;
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}
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BOOST_ASSERT(!size_);
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}
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void clear()
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{
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if (!size_) return;
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delete_nodes(get_previous_start(), link_pointer());
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clear_buckets();
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BOOST_ASSERT(!size_);
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}
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void clear_buckets()
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{
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bucket_pointer end = get_bucket(bucket_count_);
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for(bucket_pointer it = buckets_; it != end; ++it)
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{
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it->next_ = node_pointer();
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}
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}
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void destroy_buckets()
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{
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bucket_pointer end = get_bucket(bucket_count_ + 1);
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for(bucket_pointer it = buckets_; it != end; ++it)
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{
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boost::unordered::detail::func::destroy(
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boost::addressof(*it));
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}
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bucket_allocator_traits::deallocate(bucket_alloc(),
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buckets_, bucket_count_ + 1);
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}
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////////////////////////////////////////////////////////////////////////
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// Fix buckets after delete
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//
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std::size_t fix_bucket(std::size_t bucket_index, link_pointer prev)
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{
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link_pointer end = prev->next_;
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std::size_t bucket_index2 = bucket_index;
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if (end)
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{
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bucket_index2 = hash_to_bucket(
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static_cast<node_pointer>(end)->hash_);
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// If begin and end are in the same bucket, then
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// there's nothing to do.
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if (bucket_index == bucket_index2) return bucket_index2;
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// Update the bucket containing end.
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get_bucket(bucket_index2)->next_ = prev;
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}
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// Check if this bucket is now empty.
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bucket_pointer this_bucket = get_bucket(bucket_index);
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if (this_bucket->next_ == prev)
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this_bucket->next_ = link_pointer();
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return bucket_index2;
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}
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////////////////////////////////////////////////////////////////////////
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// Assignment
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void assign(table const& x)
|
|
{
|
|
if (this != boost::addressof(x))
|
|
{
|
|
assign(x,
|
|
boost::unordered::detail::integral_constant<bool,
|
|
allocator_traits<node_allocator>::
|
|
propagate_on_container_copy_assignment::value>());
|
|
}
|
|
}
|
|
|
|
void assign(table const& x, false_type)
|
|
{
|
|
// Strong exception safety.
|
|
set_hash_functions new_func_this(*this, x);
|
|
mlf_ = x.mlf_;
|
|
recalculate_max_load();
|
|
|
|
if (!size_ && !x.size_) return;
|
|
|
|
if (x.size_ >= max_load_) {
|
|
create_buckets(min_buckets_for_size(x.size_));
|
|
}
|
|
else {
|
|
clear_buckets();
|
|
}
|
|
|
|
new_func_this.commit();
|
|
static_cast<table_impl*>(this)->assign_buckets(x);
|
|
}
|
|
|
|
void assign(table const& x, true_type)
|
|
{
|
|
if (node_alloc() == x.node_alloc()) {
|
|
allocators_.assign(x.allocators_);
|
|
assign(x, false_type());
|
|
}
|
|
else {
|
|
set_hash_functions new_func_this(*this, x);
|
|
|
|
// Delete everything with current allocators before assigning
|
|
// the new ones.
|
|
delete_buckets();
|
|
allocators_.assign(x.allocators_);
|
|
|
|
// Copy over other data, all no throw.
|
|
new_func_this.commit();
|
|
mlf_ = x.mlf_;
|
|
bucket_count_ = min_buckets_for_size(x.size_);
|
|
max_load_ = 0;
|
|
|
|
// Finally copy the elements.
|
|
if (x.size_) {
|
|
static_cast<table_impl*>(this)->copy_buckets(x);
|
|
}
|
|
}
|
|
}
|
|
|
|
void move_assign(table& x)
|
|
{
|
|
if (this != boost::addressof(x))
|
|
{
|
|
move_assign(x,
|
|
boost::unordered::detail::integral_constant<bool,
|
|
allocator_traits<node_allocator>::
|
|
propagate_on_container_move_assignment::value>());
|
|
}
|
|
}
|
|
|
|
void move_assign(table& x, true_type)
|
|
{
|
|
delete_buckets();
|
|
set_hash_functions new_func_this(*this, x);
|
|
allocators_.move_assign(x.allocators_);
|
|
// No throw from here.
|
|
mlf_ = x.mlf_;
|
|
max_load_ = x.max_load_;
|
|
move_buckets_from(x);
|
|
new_func_this.commit();
|
|
}
|
|
|
|
void move_assign(table& x, false_type)
|
|
{
|
|
if (node_alloc() == x.node_alloc()) {
|
|
delete_buckets();
|
|
set_hash_functions new_func_this(*this, x);
|
|
// No throw from here.
|
|
mlf_ = x.mlf_;
|
|
max_load_ = x.max_load_;
|
|
move_buckets_from(x);
|
|
new_func_this.commit();
|
|
}
|
|
else {
|
|
set_hash_functions new_func_this(*this, x);
|
|
mlf_ = x.mlf_;
|
|
recalculate_max_load();
|
|
|
|
if (!size_ && !x.size_) {
|
|
new_func_this.commit();
|
|
return;
|
|
}
|
|
|
|
if (x.size_ >= max_load_) {
|
|
create_buckets(min_buckets_for_size(x.size_));
|
|
}
|
|
else {
|
|
clear_buckets();
|
|
}
|
|
|
|
new_func_this.commit();
|
|
static_cast<table_impl*>(this)->move_assign_buckets(x);
|
|
}
|
|
}
|
|
|
|
// Accessors
|
|
|
|
key_type const& get_key(value_type const& x) const
|
|
{
|
|
return extractor::extract(x);
|
|
}
|
|
|
|
std::size_t hash(key_type const& k) const
|
|
{
|
|
return policy::apply_hash(this->hash_function(), k);
|
|
}
|
|
|
|
// Find Node
|
|
|
|
template <typename Key, typename Hash, typename Pred>
|
|
node_pointer generic_find_node(
|
|
Key const& k,
|
|
Hash const& hf,
|
|
Pred const& eq) const
|
|
{
|
|
return static_cast<table_impl const*>(this)->
|
|
find_node_impl(policy::apply_hash(hf, k), k, eq);
|
|
}
|
|
|
|
node_pointer find_node(
|
|
std::size_t key_hash,
|
|
key_type const& k) const
|
|
{
|
|
return static_cast<table_impl const*>(this)->
|
|
find_node_impl(key_hash, k, this->key_eq());
|
|
}
|
|
|
|
node_pointer find_node(key_type const& k) const
|
|
{
|
|
return static_cast<table_impl const*>(this)->
|
|
find_node_impl(hash(k), k, this->key_eq());
|
|
}
|
|
|
|
// Reserve and rehash
|
|
|
|
void reserve_for_insert(std::size_t);
|
|
void rehash(std::size_t);
|
|
void reserve(std::size_t);
|
|
};
|
|
|
|
////////////////////////////////////////////////////////////////////////////
|
|
// Reserve & Rehash
|
|
|
|
// basic exception safety
|
|
template <typename Types>
|
|
inline void table<Types>::reserve_for_insert(std::size_t size)
|
|
{
|
|
if (!buckets_) {
|
|
create_buckets((std::max)(bucket_count_,
|
|
min_buckets_for_size(size)));
|
|
}
|
|
// According to the standard this should be 'size >= max_load_',
|
|
// but I think this is better, defect report filed.
|
|
else if(size > max_load_) {
|
|
std::size_t num_buckets
|
|
= min_buckets_for_size((std::max)(size,
|
|
size_ + (size_ >> 1)));
|
|
|
|
if (num_buckets != bucket_count_)
|
|
static_cast<table_impl*>(this)->rehash_impl(num_buckets);
|
|
}
|
|
}
|
|
|
|
// if hash function throws, basic exception safety
|
|
// strong otherwise.
|
|
|
|
template <typename Types>
|
|
inline void table<Types>::rehash(std::size_t min_buckets)
|
|
{
|
|
using namespace std;
|
|
|
|
if(!size_) {
|
|
delete_buckets();
|
|
bucket_count_ = policy::new_bucket_count(min_buckets);
|
|
}
|
|
else {
|
|
min_buckets = policy::new_bucket_count((std::max)(min_buckets,
|
|
boost::unordered::detail::double_to_size(floor(
|
|
static_cast<double>(size_) /
|
|
static_cast<double>(mlf_))) + 1));
|
|
|
|
if(min_buckets != bucket_count_)
|
|
static_cast<table_impl*>(this)->rehash_impl(min_buckets);
|
|
}
|
|
}
|
|
|
|
template <typename Types>
|
|
inline void table<Types>::reserve(std::size_t num_elements)
|
|
{
|
|
rehash(static_cast<std::size_t>(
|
|
std::ceil(static_cast<double>(num_elements) / mlf_)));
|
|
}
|
|
}}}
|
|
|
|
#if defined(BOOST_MSVC)
|
|
#pragma warning(pop)
|
|
#endif
|
|
|
|
#endif
|