boost/unordered/detail/table.hpp
// Copyright (C) 2003-2004 Jeremy B. Maitin-Shepard. // Copyright (C) 2005-2011 Daniel James // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_UNORDERED_DETAIL_ALL_HPP_INCLUDED #define BOOST_UNORDERED_DETAIL_ALL_HPP_INCLUDED #include <boost/config.hpp> #if defined(BOOST_HAS_PRAGMA_ONCE) #pragma once #endif #include <boost/unordered/detail/buckets.hpp> #include <boost/unordered/detail/util.hpp> #include <boost/type_traits/aligned_storage.hpp> #include <boost/type_traits/alignment_of.hpp> #include <cmath> #if defined(BOOST_MSVC) #pragma warning(push) #pragma warning(disable:4127) // conditional expression is constant #endif #if defined(BOOST_UNORDERED_DEPRECATED_EQUALITY) #if defined(__EDG__) #elif defined(_MSC_VER) || defined(__BORLANDC__) || defined(__DMC__) #pragma message("Warning: BOOST_UNORDERED_DEPRECATED_EQUALITY is no longer supported.") #elif defined(__GNUC__) || defined(__HP_aCC) || \ defined(__SUNPRO_CC) || defined(__IBMCPP__) #warning "BOOST_UNORDERED_DEPRECATED_EQUALITY is no longer supported." #endif #endif namespace boost { namespace unordered { namespace detail { //////////////////////////////////////////////////////////////////////////// // convert double to std::size_t inline std::size_t double_to_size(double f) { return f >= static_cast<double>( (std::numeric_limits<std::size_t>::max)()) ? (std::numeric_limits<std::size_t>::max)() : static_cast<std::size_t>(f); } // The space used to store values in a node. template <typename ValueType> struct value_base { typedef ValueType value_type; typename boost::aligned_storage< sizeof(value_type), boost::alignment_of<value_type>::value>::type data_; void* address() { return this; } value_type& value() { return *(ValueType*) this; } value_type* value_ptr() { return (ValueType*) this; } private: value_base& operator=(value_base const&); }; template <typename NodeAlloc> struct copy_nodes { typedef boost::unordered::detail::allocator_traits<NodeAlloc> node_allocator_traits; node_constructor<NodeAlloc> constructor; explicit copy_nodes(NodeAlloc& a) : constructor(a) {} typename node_allocator_traits::pointer create( typename node_allocator_traits::value_type::value_type const& v) { constructor.construct_with_value2(v); return constructor.release(); } }; template <typename NodeAlloc> struct move_nodes { typedef boost::unordered::detail::allocator_traits<NodeAlloc> node_allocator_traits; node_constructor<NodeAlloc> constructor; explicit move_nodes(NodeAlloc& a) : constructor(a) {} typename node_allocator_traits::pointer create( typename node_allocator_traits::value_type::value_type& v) { constructor.construct_with_value2(boost::move(v)); return constructor.release(); } }; template <typename Buckets> struct assign_nodes { node_holder<typename Buckets::node_allocator> holder; explicit assign_nodes(Buckets& b) : holder(b) {} typename Buckets::node_pointer create( typename Buckets::value_type const& v) { return holder.copy_of(v); } }; template <typename Buckets> struct move_assign_nodes { node_holder<typename Buckets::node_allocator> holder; explicit move_assign_nodes(Buckets& b) : holder(b) {} typename Buckets::node_pointer create( typename Buckets::value_type& v) { return holder.move_copy_of(v); } }; template <typename Types> struct table : boost::unordered::detail::functions< typename Types::hasher, typename Types::key_equal> { private: table(table const&); table& operator=(table const&); public: typedef typename Types::node node; typedef typename Types::bucket bucket; typedef typename Types::hasher hasher; typedef typename Types::key_equal key_equal; typedef typename Types::key_type key_type; typedef typename Types::extractor extractor; typedef typename Types::value_type value_type; typedef typename Types::table table_impl; typedef typename Types::link_pointer link_pointer; typedef typename Types::policy policy; typedef boost::unordered::detail::functions< typename Types::hasher, typename Types::key_equal> functions; typedef typename functions::set_hash_functions set_hash_functions; typedef typename Types::allocator allocator; typedef typename boost::unordered::detail:: rebind_wrap<allocator, node>::type node_allocator; typedef typename boost::unordered::detail:: rebind_wrap<allocator, bucket>::type bucket_allocator; typedef boost::unordered::detail::allocator_traits<node_allocator> node_allocator_traits; typedef boost::unordered::detail::allocator_traits<bucket_allocator> bucket_allocator_traits; typedef typename node_allocator_traits::pointer node_pointer; typedef typename node_allocator_traits::const_pointer const_node_pointer; typedef typename bucket_allocator_traits::pointer bucket_pointer; typedef boost::unordered::detail::node_constructor<node_allocator> node_constructor; typedef boost::unordered::iterator_detail:: iterator<node> iterator; typedef boost::unordered::iterator_detail:: c_iterator<node, const_node_pointer> c_iterator; typedef boost::unordered::iterator_detail:: l_iterator<node, policy> l_iterator; typedef boost::unordered::iterator_detail:: cl_iterator<node, const_node_pointer, policy> cl_iterator; //////////////////////////////////////////////////////////////////////// // Members boost::unordered::detail::compressed<bucket_allocator, node_allocator> allocators_; std::size_t bucket_count_; std::size_t size_; float mlf_; std::size_t max_load_; bucket_pointer buckets_; //////////////////////////////////////////////////////////////////////// // Data access bucket_allocator const& bucket_alloc() const { return allocators_.first(); } node_allocator const& node_alloc() const { return allocators_.second(); } bucket_allocator& bucket_alloc() { return allocators_.first(); } node_allocator& node_alloc() { return allocators_.second(); } std::size_t max_bucket_count() const { // -1 to account for the start bucket. return policy::prev_bucket_count( bucket_allocator_traits::max_size(bucket_alloc()) - 1); } bucket_pointer get_bucket(std::size_t bucket_index) const { BOOST_ASSERT(buckets_); return buckets_ + static_cast<std::ptrdiff_t>(bucket_index); } link_pointer get_previous_start() const { return get_bucket(bucket_count_)->first_from_start(); } link_pointer get_previous_start(std::size_t bucket_index) const { return get_bucket(bucket_index)->next_; } iterator begin() const { return size_ ? iterator(get_previous_start()->next_) : iterator(); } iterator begin(std::size_t bucket_index) const { if (!size_) return iterator(); link_pointer prev = get_previous_start(bucket_index); return prev ? iterator(prev->next_) : iterator(); } std::size_t hash_to_bucket(std::size_t hash_value) const { return policy::to_bucket(bucket_count_, hash_value); } float load_factor() const { BOOST_ASSERT(bucket_count_ != 0); return static_cast<float>(size_) / static_cast<float>(bucket_count_); } std::size_t bucket_size(std::size_t index) const { iterator it = begin(index); if (!it.node_) return 0; std::size_t count = 0; while(it.node_ && hash_to_bucket(it.node_->hash_) == index) { ++count; ++it; } return count; } //////////////////////////////////////////////////////////////////////// // Load methods std::size_t max_size() const { using namespace std; // size < mlf_ * count return boost::unordered::detail::double_to_size(ceil( static_cast<double>(mlf_) * static_cast<double>(max_bucket_count()) )) - 1; } void recalculate_max_load() { using namespace std; // From 6.3.1/13: // Only resize when size >= mlf_ * count max_load_ = buckets_ ? boost::unordered::detail::double_to_size(ceil( static_cast<double>(mlf_) * static_cast<double>(bucket_count_) )) : 0; } void max_load_factor(float z) { BOOST_ASSERT(z > 0); mlf_ = (std::max)(z, minimum_max_load_factor); recalculate_max_load(); } std::size_t min_buckets_for_size(std::size_t size) const { BOOST_ASSERT(mlf_ >= minimum_max_load_factor); using namespace std; // From 6.3.1/13: // size < mlf_ * count // => count > size / mlf_ // // Or from rehash post-condition: // count > size / mlf_ return policy::new_bucket_count( boost::unordered::detail::double_to_size(floor( static_cast<double>(size) / static_cast<double>(mlf_))) + 1); } //////////////////////////////////////////////////////////////////////// // Constructors table(std::size_t num_buckets, hasher const& hf, key_equal const& eq, node_allocator const& a) : functions(hf, eq), allocators_(a,a), bucket_count_(policy::new_bucket_count(num_buckets)), size_(0), mlf_(1.0f), max_load_(0), buckets_() {} table(table const& x, node_allocator const& a) : functions(x), allocators_(a,a), bucket_count_(x.min_buckets_for_size(x.size_)), size_(0), mlf_(x.mlf_), max_load_(0), buckets_() {} table(table& x, boost::unordered::detail::move_tag m) : functions(x, m), allocators_(x.allocators_, m), bucket_count_(x.bucket_count_), size_(x.size_), mlf_(x.mlf_), max_load_(x.max_load_), buckets_(x.buckets_) { x.buckets_ = bucket_pointer(); x.size_ = 0; x.max_load_ = 0; } table(table& x, node_allocator const& a, boost::unordered::detail::move_tag m) : functions(x, m), allocators_(a, a), bucket_count_(x.bucket_count_), size_(0), mlf_(x.mlf_), max_load_(x.max_load_), buckets_() {} //////////////////////////////////////////////////////////////////////// // Initialisation. void init(table const& x) { if (x.size_) { create_buckets(bucket_count_); copy_nodes<node_allocator> node_creator(node_alloc()); table_impl::fill_buckets(x.begin(), *this, node_creator); } } void move_init(table& x) { if(node_alloc() == x.node_alloc()) { move_buckets_from(x); } else if(x.size_) { // TODO: Could pick new bucket size? create_buckets(bucket_count_); move_nodes<node_allocator> node_creator(node_alloc()); node_holder<node_allocator> nodes(x); table_impl::fill_buckets(nodes.begin(), *this, node_creator); } } //////////////////////////////////////////////////////////////////////// // Create buckets void create_buckets(std::size_t new_count) { boost::unordered::detail::array_constructor<bucket_allocator> constructor(bucket_alloc()); // Creates an extra bucket to act as the start node. constructor.construct(bucket(), new_count + 1); if (buckets_) { // Copy the nodes to the new buckets, including the dummy // node if there is one. (constructor.get() + static_cast<std::ptrdiff_t>(new_count))->next_ = (buckets_ + static_cast<std::ptrdiff_t>( bucket_count_))->next_; destroy_buckets(); } else if (bucket::extra_node) { node_constructor a(node_alloc()); a.construct(); (constructor.get() + static_cast<std::ptrdiff_t>(new_count))->next_ = a.release(); } bucket_count_ = new_count; buckets_ = constructor.release(); recalculate_max_load(); } //////////////////////////////////////////////////////////////////////// // Swap and Move void swap_allocators(table& other, false_type) { boost::unordered::detail::func::ignore_unused_variable_warning(other); // According to 23.2.1.8, if propagate_on_container_swap is // false the behaviour is undefined unless the allocators // are equal. BOOST_ASSERT(node_alloc() == other.node_alloc()); } void swap_allocators(table& other, true_type) { allocators_.swap(other.allocators_); } // Only swaps the allocators if propagate_on_container_swap void swap(table& x) { set_hash_functions op1(*this, x); set_hash_functions op2(x, *this); // I think swap can throw if Propagate::value, // since the allocators' swap can throw. Not sure though. swap_allocators(x, boost::unordered::detail::integral_constant<bool, allocator_traits<node_allocator>:: propagate_on_container_swap::value>()); boost::swap(buckets_, x.buckets_); boost::swap(bucket_count_, x.bucket_count_); boost::swap(size_, x.size_); std::swap(mlf_, x.mlf_); std::swap(max_load_, x.max_load_); op1.commit(); op2.commit(); } void move_buckets_from(table& other) { BOOST_ASSERT(node_alloc() == other.node_alloc()); BOOST_ASSERT(!buckets_); buckets_ = other.buckets_; bucket_count_ = other.bucket_count_; size_ = other.size_; other.buckets_ = bucket_pointer(); other.size_ = 0; other.max_load_ = 0; } //////////////////////////////////////////////////////////////////////// // Delete/destruct ~table() { delete_buckets(); } void delete_node(link_pointer prev) { node_pointer n = static_cast<node_pointer>(prev->next_); prev->next_ = n->next_; boost::unordered::detail::func::destroy_value_impl(node_alloc(), n->value_ptr()); boost::unordered::detail::func::destroy(boost::addressof(*n)); node_allocator_traits::deallocate(node_alloc(), n, 1); --size_; } std::size_t delete_nodes(link_pointer prev, link_pointer end) { BOOST_ASSERT(prev->next_ != end); std::size_t count = 0; do { delete_node(prev); ++count; } while (prev->next_ != end); return count; } void delete_buckets() { if(buckets_) { if (size_) delete_nodes(get_previous_start(), link_pointer()); if (bucket::extra_node) { node_pointer n = static_cast<node_pointer>( get_bucket(bucket_count_)->next_); boost::unordered::detail::func::destroy( boost::addressof(*n)); node_allocator_traits::deallocate(node_alloc(), n, 1); } destroy_buckets(); buckets_ = bucket_pointer(); max_load_ = 0; } BOOST_ASSERT(!size_); } void clear() { if (!size_) return; delete_nodes(get_previous_start(), link_pointer()); clear_buckets(); BOOST_ASSERT(!size_); } void clear_buckets() { bucket_pointer end = get_bucket(bucket_count_); for(bucket_pointer it = buckets_; it != end; ++it) { it->next_ = node_pointer(); } } void destroy_buckets() { bucket_pointer end = get_bucket(bucket_count_ + 1); for(bucket_pointer it = buckets_; it != end; ++it) { boost::unordered::detail::func::destroy( boost::addressof(*it)); } bucket_allocator_traits::deallocate(bucket_alloc(), buckets_, bucket_count_ + 1); } //////////////////////////////////////////////////////////////////////// // Fix buckets after delete // std::size_t fix_bucket(std::size_t bucket_index, link_pointer prev) { link_pointer end = prev->next_; std::size_t bucket_index2 = bucket_index; if (end) { bucket_index2 = hash_to_bucket( static_cast<node_pointer>(end)->hash_); // If begin and end are in the same bucket, then // there's nothing to do. if (bucket_index == bucket_index2) return bucket_index2; // Update the bucket containing end. get_bucket(bucket_index2)->next_ = prev; } // Check if this bucket is now empty. bucket_pointer this_bucket = get_bucket(bucket_index); if (this_bucket->next_ == prev) this_bucket->next_ = link_pointer(); return bucket_index2; } //////////////////////////////////////////////////////////////////////// // Assignment 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); new_func_this.commit(); 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(); } // assign_nodes takes ownership of the container's elements, // assigning to them if possible, and deleting any that are // left over. assign_nodes<table> node_creator(*this); table_impl::fill_buckets(x.begin(), *this, node_creator); } 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_) { create_buckets(bucket_count_); copy_nodes<node_allocator> node_creator(node_alloc()); table_impl::fill_buckets(x.begin(), *this, node_creator); } } } 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(); allocators_.move_assign(x.allocators_); move_assign_no_alloc(x); } void move_assign(table& x, false_type) { if (node_alloc() == x.node_alloc()) { delete_buckets(); move_assign_no_alloc(x); } else { set_hash_functions new_func_this(*this, x); new_func_this.commit(); 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(); } // move_assign_nodes takes ownership of the container's // elements, assigning to them if possible, and deleting // any that are left over. move_assign_nodes<table> node_creator(*this); node_holder<node_allocator> nodes(x); table_impl::fill_buckets(nodes.begin(), *this, node_creator); } } void move_assign_no_alloc(table& x) { 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(); } // 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> iterator 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); } iterator 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()); } iterator find_node(key_type const& k) const { return static_cast<table_impl const*>(this)-> find_node_impl(hash(k), k, this->key_eq()); } iterator find_matching_node(iterator n) const { // TODO: Does this apply to C++11? // // For some stupid reason, I decided to support equality comparison // when different hash functions are used. So I can't use the hash // value from the node here. return find_node(get_key(*n)); } // 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