gcc/libstdc++-v3/include/tr1/hashtable

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C++

// Internal header for TR1 unordered_set and unordered_map -*- 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// 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.
/** @file
* This is a TR1 C++ Library header.
*/
// This header file defines std::tr1::hashtable, which is used to
// implement std::tr1::unordered_set, std::tr1::unordered_map,
// std::tr1::unordered_multiset, and std::tr1::unordered_multimap.
// hashtable has many template parameters, partly to accommodate
// the differences between those four classes and partly to
// accommodate policy choices that go beyond what TR1 calls for.
// Class template hashtable attempts to encapsulate all reasonable
// variation among hash tables that use chaining. It does not handle
// open addressing.
// References:
// M. Austern, "A Proposal to Add Hash Tables to the Standard
// Library (revision 4)," WG21 Document N1456=03-0039, 2003.
// D. E. Knuth, The Art of Computer Programming, v. 3, Sorting and Searching.
// A. Tavori and V. Dreizin, "Policy-Based Data Structures", 2004.
// http://gcc.gnu.org/onlinedocs/libstdc++/ext/pb_ds/index.html
#ifndef _TR1_HASHTABLE
#define _TR1_HASHTABLE 1
#include <utility> // For std::pair
#include <memory>
#include <iterator>
#include <cstddef>
#include <cstdlib>
#include <cmath>
#include <bits/functexcept.h>
#include <tr1/type_traits> // For true_type and false_type
#include <tr1/hashtable_policy.h>
namespace std
{
_GLIBCXX_BEGIN_NAMESPACE(tr1)
// Class template hashtable, class definition.
// Meaning of class template hashtable's template parameters
// Key and Value: arbitrary CopyConstructible types.
// Allocator: an allocator type ([lib.allocator.requirements]) whose
// value type is Value.
// ExtractKey: function object that takes a object of type Value
// and returns a value of type Key.
// Equal: function object that takes two objects of type k and returns
// a bool-like value that is true if the two objects are considered equal.
// H1: the hash function. A unary function object with argument type
// Key and result type size_t. Return values should be distributed
// over the entire range [0, numeric_limits<size_t>:::max()].
// H2: the range-hashing function (in the terminology of Tavori and
// Dreizin). A binary function object whose argument types and result
// type are all size_t. Given arguments r and N, the return value is
// in the range [0, N).
// H: the ranged hash function (Tavori and Dreizin). A binary function
// whose argument types are Key and size_t and whose result type is
// size_t. Given arguments k and N, the return value is in the range
// [0, N). Default: h(k, N) = h2(h1(k), N). If H is anything other
// than the default, H1 and H2 are ignored.
// RehashPolicy: Policy class with three members, all of which govern
// the bucket count. n_bkt(n) returns a bucket count no smaller
// than n. bkt_for_elements(n) returns a bucket count appropriate
// for an element count of n. need_rehash(n_bkt, n_elt, n_ins)
// determines whether, if the current bucket count is n_bkt and the
// current element count is n_elt, we need to increase the bucket
// count. If so, returns make_pair(true, n), where n is the new
// bucket count. If not, returns make_pair(false, <anything>).
// ??? Right now it is hard-wired that the number of buckets never
// shrinks. Should we allow RehashPolicy to change that?
// cache_hash_code: bool. true if we store the value of the hash
// function along with the value. This is a time-space tradeoff.
// Storing it may improve lookup speed by reducing the number of times
// we need to call the Equal function.
// constant_iterators: bool. true if iterator and const_iterator are
// both constant iterator types. This is true for unordered_set and
// unordered_multiset, false for unordered_map and unordered_multimap.
// unique_keys: bool. true if the return value of hashtable::count(k)
// is always at most one, false if it may be an arbitrary number. This
// true for unordered_set and unordered_map, false for unordered_multiset
// and unordered_multimap.
template<typename Key, typename Value, typename Allocator,
typename ExtractKey, typename Equal,
typename H1, typename H2, typename H,
typename RehashPolicy,
bool cache_hash_code,
bool constant_iterators,
bool unique_keys>
class hashtable
: public detail::rehash_base<RehashPolicy,
hashtable<Key, Value, Allocator, ExtractKey,
Equal, H1, H2, H, RehashPolicy,
cache_hash_code, constant_iterators,
unique_keys> >,
public detail::hash_code_base<Key, Value, ExtractKey, Equal, H1, H2, H,
cache_hash_code>,
public detail::map_base<Key, Value, ExtractKey, unique_keys,
hashtable<Key, Value, Allocator, ExtractKey,
Equal, H1, H2, H, RehashPolicy,
cache_hash_code, constant_iterators,
unique_keys> >
{
public:
typedef Allocator allocator_type;
typedef Value value_type;
typedef Key key_type;
typedef Equal key_equal;
// mapped_type, if present, comes from map_base.
// hasher, if present, comes from hash_code_base.
typedef typename Allocator::difference_type difference_type;
typedef typename Allocator::size_type size_type;
typedef typename Allocator::reference reference;
typedef typename Allocator::const_reference const_reference;
typedef detail::node_iterator<value_type, constant_iterators,
cache_hash_code>
local_iterator;
typedef detail::node_const_iterator<value_type, constant_iterators,
cache_hash_code>
const_local_iterator;
typedef detail::hashtable_iterator<value_type, constant_iterators,
cache_hash_code>
iterator;
typedef detail::hashtable_const_iterator<value_type, constant_iterators,
cache_hash_code>
const_iterator;
template<typename K, typename Pair, typename Hashtable>
friend struct detail::map_base;
private:
typedef detail::hash_node<Value, cache_hash_code> node;
typedef typename Allocator::template rebind<node>::other
node_allocator_t;
typedef typename Allocator::template rebind<node*>::other
bucket_allocator_t;
node_allocator_t m_node_allocator;
node** m_buckets;
size_type m_bucket_count;
size_type m_element_count;
RehashPolicy m_rehash_policy;
node*
m_allocate_node(const value_type& v);
void
m_deallocate_node(node* n);
void
m_deallocate_nodes(node**, size_type);
node**
m_allocate_buckets(size_type n);
void
m_deallocate_buckets(node**, size_type n);
public:
// Constructor, destructor, assignment, swap
hashtable(size_type bucket_hint,
const H1&, const H2&, const H&,
const Equal&, const ExtractKey&,
const allocator_type&);
template<typename InIter>
hashtable(InIter first, InIter last,
size_type bucket_hint,
const H1&, const H2&, const H&,
const Equal&, const ExtractKey&,
const allocator_type&);
hashtable(const hashtable&);
hashtable&
operator=(const hashtable&);
~hashtable();
void swap(hashtable&);
// Basic container operations
iterator
begin()
{
iterator i(m_buckets);
if (!i.m_cur_node)
i.m_incr_bucket();
return i;
}
const_iterator
begin() const
{
const_iterator i(m_buckets);
if (!i.m_cur_node)
i.m_incr_bucket();
return i;
}
iterator
end()
{ return iterator(m_buckets + m_bucket_count); }
const_iterator
end() const
{ return const_iterator(m_buckets + m_bucket_count); }
size_type
size() const
{ return m_element_count; }
bool
empty() const
{ return size() == 0; }
allocator_type
get_allocator() const
{ return m_node_allocator; }
size_type
max_size() const
{ return m_node_allocator.max_size(); }
// Observers
key_equal
key_eq() const
{ return this->m_eq; }
// hash_function, if present, comes from hash_code_base.
// Bucket operations
size_type
bucket_count() const
{ return m_bucket_count; }
size_type
max_bucket_count() const
{ return max_size(); }
size_type
bucket_size(size_type n) const
{ return std::distance(begin(n), end(n)); }
size_type
bucket(const key_type& k) const
{
return this->bucket_index(k, this->m_hash_code(k),
this->m_bucket_count);
}
local_iterator
begin(size_type n)
{ return local_iterator(m_buckets[n]); }
local_iterator
end(size_type)
{ return local_iterator(0); }
const_local_iterator
begin(size_type n) const
{ return const_local_iterator(m_buckets[n]); }
const_local_iterator
end(size_type) const
{ return const_local_iterator(0); }
float
load_factor() const
{
return static_cast<float>(size()) / static_cast<float>(bucket_count());
}
// max_load_factor, if present, comes from rehash_base.
// Generalization of max_load_factor. Extension, not found in TR1. Only
// useful if RehashPolicy is something other than the default.
const RehashPolicy&
rehash_policy() const
{ return m_rehash_policy; }
void
rehash_policy(const RehashPolicy&);
// Lookup.
iterator
find(const key_type& k);
const_iterator
find(const key_type& k) const;
size_type
count(const key_type& k) const;
std::pair<iterator, iterator>
equal_range(const key_type& k);
std::pair<const_iterator, const_iterator>
equal_range(const key_type& k) const;
private: // Find, insert and erase helper functions
// ??? This dispatching is a workaround for the fact that we don't
// have partial specialization of member templates; it would be
// better to just specialize insert on unique_keys. There may be a
// cleaner workaround.
typedef typename __gnu_cxx::__conditional_type<unique_keys,
std::pair<iterator, bool>, iterator>::__type
Insert_Return_Type;
typedef typename __gnu_cxx::__conditional_type<unique_keys,
std::_Select1st<Insert_Return_Type>,
std::_Identity<Insert_Return_Type>
>::__type
Insert_Conv_Type;
node*
m_find_node(node*, const key_type&,
typename hashtable::hash_code_t) const;
iterator
m_insert_bucket(const value_type&, size_type,
typename hashtable::hash_code_t);
std::pair<iterator, bool>
m_insert(const value_type&, std::tr1::true_type);
iterator
m_insert(const value_type&, std::tr1::false_type);
void
m_erase_node(node*, node**);
public:
// Insert and erase
Insert_Return_Type
insert(const value_type& v)
{ return m_insert(v, std::tr1::integral_constant<bool, unique_keys>()); }
iterator
insert(iterator, const value_type& v)
{ return iterator(Insert_Conv_Type()(this->insert(v))); }
const_iterator
insert(const_iterator, const value_type& v)
{ return const_iterator(Insert_Conv_Type()(this->insert(v))); }
template<typename InIter>
void
insert(InIter first, InIter last);
iterator
erase(iterator);
const_iterator
erase(const_iterator);
size_type
erase(const key_type&);
iterator
erase(iterator, iterator);
const_iterator
erase(const_iterator, const_iterator);
void
clear();
// Set number of buckets to be appropriate for container of n element.
void rehash(size_type n);
private:
// Unconditionally change size of bucket array to n.
void m_rehash(size_type n);
};
// Definitions of class template hashtable's out-of-line member functions.
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::node*
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_allocate_node(const value_type& v)
{
node* n = m_node_allocator.allocate(1);
try
{
get_allocator().construct(&n->m_v, v);
n->m_next = 0;
return n;
}
catch(...)
{
m_node_allocator.deallocate(n, 1);
__throw_exception_again;
}
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_deallocate_node(node* n)
{
get_allocator().destroy(&n->m_v);
m_node_allocator.deallocate(n, 1);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_deallocate_nodes(node** array, size_type n)
{
for (size_type i = 0; i < n; ++i)
{
node* p = array[i];
while (p)
{
node* tmp = p;
p = p->m_next;
m_deallocate_node(tmp);
}
array[i] = 0;
}
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::node**
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_allocate_buckets(size_type n)
{
bucket_allocator_t alloc(m_node_allocator);
// We allocate one extra bucket to hold a sentinel, an arbitrary
// non-null pointer. Iterator increment relies on this.
node** p = alloc.allocate(n + 1);
std::fill(p, p + n, (node*) 0);
p[n] = reinterpret_cast<node*>(0x1000);
return p;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_deallocate_buckets(node** p, size_type n)
{
bucket_allocator_t alloc(m_node_allocator);
alloc.deallocate(p, n + 1);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
hashtable(size_type bucket_hint,
const H1& h1, const H2& h2, const H& h,
const Eq& eq, const Ex& exk,
const allocator_type& a)
: detail::rehash_base<RP, hashtable>(),
detail::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>(exk, eq, h1, h2, h),
detail::map_base<K, V, Ex, u, hashtable>(),
m_node_allocator(a),
m_bucket_count(0),
m_element_count(0),
m_rehash_policy()
{
m_bucket_count = m_rehash_policy.next_bkt(bucket_hint);
m_buckets = m_allocate_buckets(m_bucket_count);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
template<typename InIter>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
hashtable(InIter f, InIter l,
size_type bucket_hint,
const H1& h1, const H2& h2, const H& h,
const Eq& eq, const Ex& exk,
const allocator_type& a)
: detail::rehash_base<RP, hashtable>(),
detail::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>(exk, eq,
h1, h2, h),
detail::map_base<K, V, Ex, u, hashtable>(),
m_node_allocator(a),
m_bucket_count(0),
m_element_count(0),
m_rehash_policy()
{
m_bucket_count = std::max(m_rehash_policy.next_bkt(bucket_hint),
m_rehash_policy.
bkt_for_elements(detail::
distance_fw(f, l)));
m_buckets = m_allocate_buckets(m_bucket_count);
try
{
for (; f != l; ++f)
this->insert(*f);
}
catch(...)
{
clear();
m_deallocate_buckets(m_buckets, m_bucket_count);
__throw_exception_again;
}
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
hashtable(const hashtable& ht)
: detail::rehash_base<RP, hashtable>(ht),
detail::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>(ht),
detail::map_base<K, V, Ex, u, hashtable>(ht),
m_node_allocator(ht.get_allocator()),
m_bucket_count(ht.m_bucket_count),
m_element_count(ht.m_element_count),
m_rehash_policy(ht.m_rehash_policy)
{
m_buckets = m_allocate_buckets(m_bucket_count);
try
{
for (size_type i = 0; i < ht.m_bucket_count; ++i)
{
node* n = ht.m_buckets[i];
node** tail = m_buckets + i;
while (n)
{
*tail = m_allocate_node(n->m_v);
this->copy_code(*tail, n);
tail = &((*tail)->m_next);
n = n->m_next;
}
}
}
catch(...)
{
clear();
m_deallocate_buckets(m_buckets, m_bucket_count);
__throw_exception_again;
}
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>&
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
operator=(const hashtable& ht)
{
hashtable tmp(ht);
this->swap(tmp);
return *this;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
~hashtable()
{
clear();
m_deallocate_buckets(m_buckets, m_bucket_count);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
swap(hashtable& x)
{
// The only base class with member variables is hash_code_base. We
// define hash_code_base::m_swap because different specializations
// have different members.
detail::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>::m_swap(x);
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 431. Swapping containers with unequal allocators.
std::__alloc_swap<node_allocator_t>::_S_do_it(m_node_allocator,
x.m_node_allocator);
std::swap(m_rehash_policy, x.m_rehash_policy);
std::swap(m_buckets, x.m_buckets);
std::swap(m_bucket_count, x.m_bucket_count);
std::swap(m_element_count, x.m_element_count);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
rehash_policy(const RP& pol)
{
m_rehash_policy = pol;
size_type n_bkt = pol.bkt_for_elements(m_element_count);
if (n_bkt > m_bucket_count)
m_rehash(n_bkt);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
find(const key_type& k)
{
typename hashtable::hash_code_t code = this->m_hash_code(k);
std::size_t n = this->bucket_index(k, code, this->bucket_count());
node* p = m_find_node(m_buckets[n], k, code);
return p ? iterator(p, m_buckets + n) : this->end();
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::const_iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
find(const key_type& k) const
{
typename hashtable::hash_code_t code = this->m_hash_code(k);
std::size_t n = this->bucket_index(k, code, this->bucket_count());
node* p = m_find_node(m_buckets[n], k, code);
return p ? const_iterator(p, m_buckets + n) : this->end();
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::size_type
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
count(const key_type& k) const
{
typename hashtable::hash_code_t code = this->m_hash_code(k);
std::size_t n = this->bucket_index(k, code, this->bucket_count());
std::size_t result = 0;
for (node* p = m_buckets[n]; p; p = p->m_next)
if (this->compare(k, code, p))
++result;
return result;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
std::pair<typename hashtable<K, V, A, Ex, Eq, H1,
H2, H, RP, c, ci, u>::iterator,
typename hashtable<K, V, A, Ex, Eq, H1,
H2, H, RP, c, ci, u>::iterator>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
equal_range(const key_type& k)
{
typename hashtable::hash_code_t code = this->m_hash_code(k);
std::size_t n = this->bucket_index(k, code, this->bucket_count());
node** head = m_buckets + n;
node* p = m_find_node(*head, k, code);
if (p)
{
node* p1 = p->m_next;
for (; p1; p1 = p1->m_next)
if (!this->compare(k, code, p1))
break;
iterator first(p, head);
iterator last(p1, head);
if (!p1)
last.m_incr_bucket();
return std::make_pair(first, last);
}
else
return std::make_pair(this->end(), this->end());
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
std::pair<typename hashtable<K, V, A, Ex, Eq, H1,
H2, H, RP, c, ci, u>::const_iterator,
typename hashtable<K, V, A, Ex, Eq, H1,
H2, H, RP, c, ci, u>::const_iterator>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
equal_range(const key_type& k) const
{
typename hashtable::hash_code_t code = this->m_hash_code(k);
std::size_t n = this->bucket_index(k, code, this->bucket_count());
node** head = m_buckets + n;
node* p = m_find_node(*head, k, code);
if (p)
{
node* p1 = p->m_next;
for (; p1; p1 = p1->m_next)
if (!this->compare(k, code, p1))
break;
const_iterator first(p, head);
const_iterator last(p1, head);
if (!p1)
last.m_incr_bucket();
return std::make_pair(first, last);
}
else
return std::make_pair(this->end(), this->end());
}
// Find the node whose key compares equal to k, beginning the search
// at p (usually the head of a bucket). Return nil if no node is found.
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::node*
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_find_node(node* p, const key_type& k,
typename hashtable::hash_code_t code) const
{
for (; p; p = p->m_next)
if (this->compare(k, code, p))
return p;
return false;
}
// Insert v in bucket n (assumes no element with its key already present).
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_insert_bucket(const value_type& v, size_type n,
typename hashtable::hash_code_t code)
{
std::pair<bool, std::size_t> do_rehash
= m_rehash_policy.need_rehash(m_bucket_count, m_element_count, 1);
// Allocate the new node before doing the rehash so that we don't
// do a rehash if the allocation throws.
node* new_node = m_allocate_node(v);
try
{
if (do_rehash.first)
{
const key_type& k = this->m_extract(v);
n = this->bucket_index(k, code, do_rehash.second);
m_rehash(do_rehash.second);
}
new_node->m_next = m_buckets[n];
this->store_code(new_node, code);
m_buckets[n] = new_node;
++m_element_count;
return iterator(new_node, m_buckets + n);
}
catch(...)
{
m_deallocate_node(new_node);
__throw_exception_again;
}
}
// Insert v if no element with its key is already present.
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
std::pair<typename hashtable<K, V, A, Ex, Eq, H1,
H2, H, RP, c, ci, u>::iterator, bool>
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_insert(const value_type& v, std::tr1::true_type)
{
const key_type& k = this->m_extract(v);
typename hashtable::hash_code_t code = this->m_hash_code(k);
size_type n = this->bucket_index(k, code, m_bucket_count);
if (node* p = m_find_node(m_buckets[n], k, code))
return std::make_pair(iterator(p, m_buckets + n), false);
return std::make_pair(m_insert_bucket(v, n, code), true);
}
// Insert v unconditionally.
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_insert(const value_type& v, std::tr1::false_type)
{
std::pair<bool, std::size_t> do_rehash
= m_rehash_policy.need_rehash(m_bucket_count, m_element_count, 1);
if (do_rehash.first)
m_rehash(do_rehash.second);
const key_type& k = this->m_extract(v);
typename hashtable::hash_code_t code = this->m_hash_code(k);
size_type n = this->bucket_index(k, code, m_bucket_count);
// First find the node, avoid leaking new_node if compare throws.
node* prev = m_find_node(m_buckets[n], k, code);
node* new_node = m_allocate_node(v);
if (prev)
{
new_node->m_next = prev->m_next;
prev->m_next = new_node;
}
else
{
new_node->m_next = m_buckets[n];
m_buckets[n] = new_node;
}
this->store_code(new_node, code);
++m_element_count;
return iterator(new_node, m_buckets + n);
}
// For erase(iterator) and erase(const_iterator).
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_erase_node(node* p, node** b)
{
node* cur = *b;
if (cur == p)
*b = cur->m_next;
else
{
node* next = cur->m_next;
while (next != p)
{
cur = next;
next = cur->m_next;
}
cur->m_next = next->m_next;
}
m_deallocate_node(p);
--m_element_count;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
template<typename InIter>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
insert(InIter first, InIter last)
{
size_type n_elt = detail::distance_fw(first, last);
std::pair<bool, std::size_t> do_rehash
= m_rehash_policy.need_rehash(m_bucket_count, m_element_count, n_elt);
if (do_rehash.first)
m_rehash(do_rehash.second);
for (; first != last; ++first)
this->insert(*first);
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
erase(iterator it)
{
iterator result = it;
++result;
m_erase_node(it.m_cur_node, it.m_cur_bucket);
return result;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::const_iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
erase(const_iterator it)
{
const_iterator result = it;
++result;
m_erase_node(it.m_cur_node, it.m_cur_bucket);
return result;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::size_type
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
erase(const key_type& k)
{
typename hashtable::hash_code_t code = this->m_hash_code(k);
std::size_t n = this->bucket_index(k, code, m_bucket_count);
size_type result = 0;
node** slot = m_buckets + n;
while (*slot && !this->compare(k, code, *slot))
slot = &((*slot)->m_next);
while (*slot && this->compare(k, code, *slot))
{
node* p = *slot;
*slot = p->m_next;
m_deallocate_node(p);
--m_element_count;
++result;
}
return result;
}
// ??? This could be optimized by taking advantage of the bucket
// structure, but it's not clear that it's worth doing. It probably
// wouldn't even be an optimization unless the load factor is large.
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
erase(iterator first, iterator last)
{
while (first != last)
first = this->erase(first);
return last;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
typename hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::const_iterator
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
erase(const_iterator first, const_iterator last)
{
while (first != last)
first = this->erase(first);
return last;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
clear()
{
m_deallocate_nodes(m_buckets, m_bucket_count);
m_element_count = 0;
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
rehash(size_type n)
{
m_rehash(std::max(m_rehash_policy.next_bkt(n),
m_rehash_policy.bkt_for_elements(m_element_count
+ 1)));
}
template<typename K, typename V,
typename A, typename Ex, typename Eq,
typename H1, typename H2, typename H, typename RP,
bool c, bool ci, bool u>
void
hashtable<K, V, A, Ex, Eq, H1, H2, H, RP, c, ci, u>::
m_rehash(size_type n)
{
node** new_array = m_allocate_buckets(n);
try
{
for (size_type i = 0; i < m_bucket_count; ++i)
while (node* p = m_buckets[i])
{
std::size_t new_index = this->bucket_index(p, n);
m_buckets[i] = p->m_next;
p->m_next = new_array[new_index];
new_array[new_index] = p;
}
m_deallocate_buckets(m_buckets, m_bucket_count);
m_bucket_count = n;
m_buckets = new_array;
}
catch(...)
{
// A failure here means that a hash function threw an exception.
// We can't restore the previous state without calling the hash
// function again, so the only sensible recovery is to delete
// everything.
m_deallocate_nodes(new_array, n);
m_deallocate_buckets(new_array, n);
m_deallocate_nodes(m_buckets, m_bucket_count);
m_element_count = 0;
__throw_exception_again;
}
}
_GLIBCXX_END_NAMESPACE
} // namespace std::tr1
#endif // _TR1_HASHTABLE