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boost_unordered/include/boost/unordered/detail/unique.hpp
2011-08-18 19:29:02 +00:00

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// 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_UNIQUE_HPP_INCLUDED
#define BOOST_UNORDERED_DETAIL_UNIQUE_HPP_INCLUDED
#include <boost/unordered/detail/extract_key.hpp>
namespace boost { namespace unordered { namespace detail {
template <class T>
class unique_table : public T::table_base
{
public:
typedef BOOST_DEDUCED_TYPENAME T::hasher hasher;
typedef BOOST_DEDUCED_TYPENAME T::key_equal key_equal;
typedef BOOST_DEDUCED_TYPENAME T::value_allocator value_allocator;
typedef BOOST_DEDUCED_TYPENAME T::key_type key_type;
typedef BOOST_DEDUCED_TYPENAME T::value_type value_type;
typedef BOOST_DEDUCED_TYPENAME T::table_base table_base;
typedef BOOST_DEDUCED_TYPENAME T::node_constructor node_constructor;
typedef BOOST_DEDUCED_TYPENAME T::node_allocator node_allocator;
typedef BOOST_DEDUCED_TYPENAME T::node node;
typedef BOOST_DEDUCED_TYPENAME T::node_ptr node_ptr;
typedef BOOST_DEDUCED_TYPENAME T::bucket_ptr bucket_ptr;
typedef BOOST_DEDUCED_TYPENAME T::extractor extractor;
typedef std::pair<node_ptr, bool> emplace_return;
// Constructors
unique_table(std::size_t n, hasher const& hf, key_equal const& eq,
value_allocator const& a)
: table_base(n, hf, eq, a) {}
unique_table(unique_table const& x)
: table_base(x,
allocator_traits<node_allocator>::
select_on_container_copy_construction(x.node_alloc())) {}
unique_table(unique_table const& x, value_allocator const& a)
: table_base(x, a) {}
unique_table(unique_table& x, move_tag m)
: table_base(x, m) {}
unique_table(unique_table& x, value_allocator const& a,
move_tag m)
: table_base(x, a, m) {}
~unique_table() {}
// equals
bool equals(unique_table const& other) const
{
if(this->size_ != other.size_) return false;
if(!this->size_) return true;
for(node_ptr n1 = this->get_bucket(this->bucket_count_)->next_;
n1; n1 = n1->next_)
{
node_ptr n2 = other.find_matching_node(n1);
if(!n2 || node::get_value(n1) != node::get_value(n2))
return false;
}
return true;
}
////////////////////////////////////////////////////////////////////////
// A convenience method for adding nodes.
node_ptr add_node(
node_constructor& a,
std::size_t bucket_index,
std::size_t hash)
{
bucket_ptr b = this->get_bucket(bucket_index);
node_ptr n = a.release();
node::set_hash(n, hash);
if (!b->next_)
{
bucket_ptr start_node = this->get_bucket(this->bucket_count_);
if (start_node->next_) {
this->buckets_[
node::get_hash(start_node->next_) % this->bucket_count_
].next_ = n;
}
b->next_ = start_node;
n->next_ = start_node->next_;
start_node->next_ = n;
}
else
{
n->next_ = b->next_->next_;
b->next_->next_ = n;
}
++this->size_;
return n;
}
////////////////////////////////////////////////////////////////////////////
// Insert methods
// if hash function throws, basic exception safety
// strong otherwise
value_type& operator[](key_type const& k)
{
typedef BOOST_DEDUCED_TYPENAME value_type::second_type mapped_type;
std::size_t hash = this->hash_function()(k);
std::size_t bucket_index = hash % this->bucket_count_;
node_ptr pos = this->find_node(bucket_index, hash, k);
if (BOOST_UNORDERED_BORLAND_BOOL(pos)) {
return node::get_value(pos);
}
// Create the node before rehashing in case it throws an
// exception (need strong safety in such a case).
node_constructor a(*this);
a.construct_pair(k, (mapped_type*) 0);
// reserve has basic exception safety if the hash function
// throws, strong otherwise.
if(this->reserve_for_insert(this->size_ + 1))
bucket_index = hash % this->bucket_count_;
// Nothing after this point can throw.
return node::get_value(add_node(a, bucket_index, hash));
}
emplace_return emplace_impl_with_node(node_constructor& a)
{
// No side effects in this initial code
key_type const& k = this->get_key(a.value());
std::size_t hash = this->hash_function()(k);
std::size_t bucket_index = hash % this->bucket_count_;
node_ptr pos = this->find_node(bucket_index, hash, k);
if (BOOST_UNORDERED_BORLAND_BOOL(pos)) {
// Found an existing key, return it (no throw).
return emplace_return(pos, false);
}
// reserve has basic exception safety if the hash function
// throws, strong otherwise.
if(this->reserve_for_insert(this->size_ + 1))
bucket_index = hash % this->bucket_count_;
// Nothing after this point can throw.
return emplace_return(add_node(a, bucket_index, hash), true);
}
emplace_return insert(value_type const& v)
{
key_type const& k = extractor::extract(v);
std::size_t hash = this->hash_function()(k);
std::size_t bucket_index = hash % this->bucket_count_;
node_ptr pos = this->find_node(bucket_index, hash, k);
if (BOOST_UNORDERED_BORLAND_BOOL(pos)) {
// Found an existing key, return it (no throw).
return emplace_return(pos, false);
}
// Isn't in table, add to bucket.
// Create the node before rehashing in case it throws an
// exception (need strong safety in such a case).
node_constructor a(*this);
a.construct(v);
// reserve has basic exception safety if the hash function
// throws, strong otherwise.
if(this->reserve_for_insert(this->size_ + 1))
bucket_index = hash % this->bucket_count_;
// Nothing after this point can throw.
return emplace_return(add_node(a, bucket_index, hash), true);
}
#if defined(BOOST_UNORDERED_STD_FORWARD_MOVE)
template<class... Args>
emplace_return emplace(Args&&... args)
{
return emplace_impl(
extractor::extract(std::forward<Args>(args)...),
std::forward<Args>(args)...);
}
template<class... Args>
emplace_return emplace_impl(key_type const& k, Args&&... args)
{
// No side effects in this initial code
std::size_t hash = this->hash_function()(k);
std::size_t bucket_index = hash % this->bucket_count_;
node_ptr pos = this->find_node(bucket_index, hash, k);
if (BOOST_UNORDERED_BORLAND_BOOL(pos)) {
// Found an existing key, return it (no throw).
return emplace_return(pos, false);
}
// Doesn't already exist, add to bucket.
// Side effects only in this block.
// Create the node before rehashing in case it throws an
// exception (need strong safety in such a case).
node_constructor a(*this);
a.construct(std::forward<Args>(args)...);
// reserve has basic exception safety if the hash function
// throws, strong otherwise.
if(this->reserve_for_insert(this->size_ + 1))
bucket_index = hash % this->bucket_count_;
// Nothing after this point can throw.
return emplace_return(add_node(a, bucket_index, hash), true);
}
template<class... Args>
emplace_return emplace_impl(no_key, Args&&... args)
{
// Construct the node regardless - in order to get the key.
// It will be discarded if it isn't used
node_constructor a(*this);
a.construct(std::forward<Args>(args)...);
return emplace_impl_with_node(a);
}
#else
template <class Arg0>
emplace_return emplace(BOOST_FWD_REF(Arg0) arg0)
{
return emplace_impl(
extractor::extract(boost::forward<Arg0>(arg0)),
boost::forward<Arg0>(arg0));
}
#define BOOST_UNORDERED_INSERT1_IMPL(z, n, _) \
template <BOOST_UNORDERED_TEMPLATE_ARGS(z, n)> \
emplace_return emplace( \
BOOST_UNORDERED_FUNCTION_PARAMS(z, n)) \
{ \
return emplace_impl(extractor::extract(arg0, arg1), \
BOOST_UNORDERED_CALL_PARAMS(z, n)); \
}
#define BOOST_UNORDERED_INSERT2_IMPL(z, n, _) \
template <BOOST_UNORDERED_TEMPLATE_ARGS(z, n)> \
emplace_return emplace_impl(key_type const& k, \
BOOST_UNORDERED_FUNCTION_PARAMS(z, n)) \
{ \
std::size_t hash = this->hash_function()(k); \
std::size_t bucket_index = hash % this->bucket_count_; \
node_ptr pos = this->find_node(bucket_index, hash, k); \
\
if (BOOST_UNORDERED_BORLAND_BOOL(pos)) { \
return emplace_return(pos, false); \
} else { \
node_constructor a(*this); \
a.construct(BOOST_UNORDERED_CALL_PARAMS(z, n)); \
\
if(this->reserve_for_insert(this->size_ + 1)) \
bucket_index = hash % this->bucket_count_; \
\
return emplace_return( \
add_node(a, bucket_index, hash), \
true); \
} \
} \
\
template <BOOST_UNORDERED_TEMPLATE_ARGS(z, n)> \
emplace_return emplace_impl(no_key, \
BOOST_UNORDERED_FUNCTION_PARAMS(z, n)) \
{ \
node_constructor a(*this); \
a.construct(BOOST_UNORDERED_CALL_PARAMS(z, n)); \
return emplace_impl_with_node(a); \
}
BOOST_PP_REPEAT_FROM_TO(2, BOOST_UNORDERED_EMPLACE_LIMIT,
BOOST_UNORDERED_INSERT1_IMPL, _)
BOOST_PP_REPEAT_FROM_TO(1, BOOST_UNORDERED_EMPLACE_LIMIT,
BOOST_UNORDERED_INSERT2_IMPL, _)
#undef BOOST_UNORDERED_INSERT1_IMPL
#undef BOOST_UNORDERED_INSERT2_IMPL
#endif
////////////////////////////////////////////////////////////////////////
// Insert range methods
//
// if hash function throws, or inserting > 1 element, basic exception
// safety strong otherwise
template <class InputIt>
void insert_range(InputIt i, InputIt j)
{
if(i != j)
return insert_range_impl(extractor::extract(*i), i, j);
}
template <class InputIt>
void insert_range_impl(key_type const&, InputIt i, InputIt j)
{
node_constructor a(*this);
// Special case for empty buckets so that we can use
// max_load_ (which isn't valid when buckets_ is null).
if (!this->buckets_) {
insert_range_empty(a, extractor::extract(*i), i, j);
if (++i == j) return;
}
do {
// Note: can't use get_key as '*i' might not be value_type - it
// could be a pair with first_types as key_type without const or a
// different second_type.
//
// TODO: Might be worth storing the value_type instead of the key
// here. Could be more efficient if '*i' is expensive. Could be
// less efficient if copying the full value_type is expensive.
insert_range_impl2(a, extractor::extract(*i), i, j);
} while(++i != j);
}
template <class InputIt>
void insert_range_empty(node_constructor& a, key_type const& k,
InputIt i, InputIt j)
{
std::size_t hash = this->hash_function()(k);
a.construct(*i);
this->reserve_for_insert(this->size_ + insert_size(i, j));
add_node(a, hash % this->bucket_count_, hash);
}
template <class InputIt>
void insert_range_impl2(node_constructor& a, key_type const& k,
InputIt i, InputIt j)
{
// No side effects in this initial code
std::size_t hash = this->hash_function()(k);
std::size_t bucket_index = hash % this->bucket_count_;
node_ptr pos = this->find_node(bucket_index, hash, k);
if (!BOOST_UNORDERED_BORLAND_BOOL(pos)) {
// Doesn't already exist, add to bucket.
// Side effects only in this block.
// Create the node before rehashing in case it throws an
// exception (need strong safety in such a case).
a.construct(*i);
// reserve has basic exception safety if the hash function
// throws, strong otherwise.
if(this->size_ + 1 >= this->max_load_) {
this->reserve_for_insert(this->size_ + insert_size(i, j));
bucket_index = hash % this->bucket_count_;
}
// Nothing after this point can throw.
add_node(a, bucket_index, hash);
}
}
template <class InputIt>
void insert_range_impl(no_key, InputIt i, InputIt j)
{
node_constructor a(*this);
do {
// No side effects in this initial code
a.construct(*i);
emplace_impl_with_node(a);
} while(++i != j);
}
};
template <class H, class P, class A>
struct set : public types<
BOOST_DEDUCED_TYPENAME allocator_traits<A>::value_type,
BOOST_DEDUCED_TYPENAME allocator_traits<A>::value_type,
H, P, A,
set_extractor<BOOST_DEDUCED_TYPENAME allocator_traits<A>::value_type>,
true>
{
typedef ::boost::unordered::detail::unique_table<set<H, P, A> > impl;
typedef ::boost::unordered::detail::table<set<H, P, A> > table_base;
};
template <class K, class H, class P, class A>
struct map : public types<
K, BOOST_DEDUCED_TYPENAME allocator_traits<A>::value_type,
H, P, A,
map_extractor<K, BOOST_DEDUCED_TYPENAME allocator_traits<A>::value_type>,
true>
{
typedef ::boost::unordered::detail::unique_table<map<K, H, P, A> > impl;
typedef ::boost::unordered::detail::table<map<K, H, P, A> > table_base;
};
}}}
#endif