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gcc/libstdc++-v3/include/tr1/hashtable
Paolo Carlini 76f5f4414f hashtable (hashtable::m_erase): Rename to erase_node. 
2005-10-14  Paolo Carlini  <pcarlini@suse.de>

	* include/tr1/hashtable (hashtable::m_erase): Rename to erase_node.
	(hashtable::erase(iterator), erase(const_iterator)): Adjust.

From-SVN: r105401
2005-10-14 10:43:30 +00:00

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// Internal header for TR1 unordered_set and unordered_map -*- C++ -*-
// Copyright (C) 2005 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.
// ??? Arguably this should be Internal::hashtable, not std::tr1::hashtable.
// 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, "Generic Associative Containers", 2004.
// ??? Full citation?
#ifndef GNU_LIBSTDCXX_TR1_HASHTABLE_
#define GNU_LIBSTDCXX_TR1_HASHTABLE_
#include <utility> // For std::pair
#include <iterator>
#include <cstddef>
#include <cstdlib>
#include <cmath>
#include <bits/functexcept.h>
#include <tr1/type_traits> // For true_type and false_type
//----------------------------------------------------------------------
// General utilities
namespace Internal
{
template<bool Flag, typename IfTrue, typename IfFalse>
struct IF;
template<typename IfTrue, typename IfFalse>
struct IF<true, IfTrue, IfFalse>
{ typedef IfTrue type; };
template <typename IfTrue, typename IfFalse>
struct IF<false, IfTrue, IfFalse>
{ typedef IfFalse type; };
// Helper function: return distance(first, last) for forward
// iterators, or 0 for input iterators.
template<class Iterator>
inline typename std::iterator_traits<Iterator>::difference_type
distance_fw(Iterator first, Iterator last, std::input_iterator_tag)
{ return 0; }
template<class Iterator>
inline typename std::iterator_traits<Iterator>::difference_type
distance_fw(Iterator first, Iterator last, std::forward_iterator_tag)
{ return std::distance(first, last); }
template<class Iterator>
inline typename std::iterator_traits<Iterator>::difference_type
distance_fw(Iterator first, Iterator last)
{
typedef typename std::iterator_traits<Iterator>::iterator_category tag;
return distance_fw(first, last, tag());
}
} // namespace Internal
//----------------------------------------------------------------------
// Auxiliary types used for all instantiations of hashtable: nodes
// and iterators.
// Nodes, used to wrap elements stored in the hash table. A policy
// template parameter of class template hashtable controls whether
// nodes also store a hash code. In some cases (e.g. strings) this may
// be a performance win.
namespace Internal
{
template<typename Value, bool cache_hash_code>
struct hash_node;
template<typename Value>
struct hash_node<Value, true>
{
Value m_v;
std::size_t hash_code;
hash_node* m_next;
};
template<typename Value>
struct hash_node<Value, false>
{
Value m_v;
hash_node* m_next;
};
// Local iterators, used to iterate within a bucket but not between
// buckets.
template<typename Value, bool cache>
struct node_iterator_base
{
node_iterator_base(hash_node<Value, cache>* p)
: m_cur(p) { }
void
incr()
{ m_cur = m_cur->m_next; }
hash_node<Value, cache>* m_cur;
};
template<typename Value, bool cache>
inline bool
operator==(const node_iterator_base<Value, cache>& x,
const node_iterator_base<Value, cache>& y)
{ return x.m_cur == y.m_cur; }
template<typename Value, bool cache>
inline bool
operator!=(const node_iterator_base<Value, cache>& x,
const node_iterator_base<Value, cache>& y)
{ return x.m_cur != y.m_cur; }
template<typename Value, bool constant_iterators, bool cache>
struct node_iterator
: public node_iterator_base<Value, cache>
{
typedef Value value_type;
typedef typename IF<constant_iterators, const Value*, Value*>::type
pointer;
typedef typename IF<constant_iterators, const Value&, Value&>::type
reference;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
explicit
node_iterator(hash_node<Value, cache>* p = 0)
: node_iterator_base<Value, cache>(p) { }
reference
operator*() const
{ return this->m_cur->m_v; }
pointer
operator->() const
{ return &this->m_cur->m_v; }
node_iterator&
operator++()
{
this->incr();
return *this;
}
node_iterator
operator++(int)
{
node_iterator tmp(*this);
this->incr();
return tmp;
}
};
template<typename Value, bool constant_iterators, bool cache>
struct node_const_iterator
: public node_iterator_base<Value, cache>
{
typedef Value value_type;
typedef const Value* pointer;
typedef const Value& reference;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
explicit
node_const_iterator(hash_node<Value, cache>* p = 0)
: node_iterator_base<Value, cache>(p) { }
node_const_iterator(const node_iterator<Value, constant_iterators,
cache>& x)
: node_iterator_base<Value, cache>(x.m_cur) { }
reference
operator*() const
{ return this->m_cur->m_v; }
pointer
operator->() const
{ return &this->m_cur->m_v; }
node_const_iterator&
operator++()
{
this->incr();
return *this;
}
node_const_iterator
operator++(int)
{
node_const_iterator tmp(*this);
this->incr();
return tmp;
}
};
template<typename Value, bool cache>
struct hashtable_iterator_base
{
hashtable_iterator_base(hash_node<Value, cache>* node,
hash_node<Value, cache>** bucket)
: m_cur_node(node), m_cur_bucket(bucket)
{ }
void
incr()
{
m_cur_node = m_cur_node->m_next;
if (!m_cur_node)
m_incr_bucket();
}
void
m_incr_bucket();
hash_node<Value, cache>* m_cur_node;
hash_node<Value, cache>** m_cur_bucket;
};
// Global iterators, used for arbitrary iteration within a hash
// table. Larger and more expensive than local iterators.
template<typename Value, bool cache>
void
hashtable_iterator_base<Value, cache>::
m_incr_bucket()
{
++m_cur_bucket;
// This loop requires the bucket array to have a non-null sentinel.
while (!*m_cur_bucket)
++m_cur_bucket;
m_cur_node = *m_cur_bucket;
}
template<typename Value, bool cache>
inline bool
operator==(const hashtable_iterator_base<Value, cache>& x,
const hashtable_iterator_base<Value, cache>& y)
{ return x.m_cur_node == y.m_cur_node; }
template<typename Value, bool cache>
inline bool
operator!=(const hashtable_iterator_base<Value, cache>& x,
const hashtable_iterator_base<Value, cache>& y)
{ return x.m_cur_node != y.m_cur_node; }
template<typename Value, bool constant_iterators, bool cache>
struct hashtable_iterator
: public hashtable_iterator_base<Value, cache>
{
typedef Value value_type;
typedef typename IF<constant_iterators, const Value*, Value*>::type
pointer;
typedef typename IF<constant_iterators, const Value&, Value&>::type
reference;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
hashtable_iterator(hash_node<Value, cache>* p,
hash_node<Value, cache>** b)
: hashtable_iterator_base<Value, cache>(p, b) { }
explicit
hashtable_iterator(hash_node<Value, cache>** b)
: hashtable_iterator_base<Value, cache>(*b, b) { }
reference
operator*() const
{ return this->m_cur_node->m_v; }
pointer
operator->() const
{ return &this->m_cur_node->m_v; }
hashtable_iterator&
operator++()
{
this->incr();
return *this;
}
hashtable_iterator
operator++(int)
{
hashtable_iterator tmp(*this);
this->incr();
return tmp;
}
};
template<typename Value, bool constant_iterators, bool cache>
struct hashtable_const_iterator
: public hashtable_iterator_base<Value, cache>
{
typedef Value value_type;
typedef const Value* pointer;
typedef const Value& reference;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
hashtable_const_iterator(hash_node<Value, cache>* p,
hash_node<Value, cache>** b)
: hashtable_iterator_base<Value, cache>(p, b) { }
explicit
hashtable_const_iterator(hash_node<Value, cache>** b)
: hashtable_iterator_base<Value, cache>(*b, b) { }
hashtable_const_iterator(const hashtable_iterator<Value,
constant_iterators, cache>& x)
: hashtable_iterator_base<Value, cache>(x.m_cur_node, x.m_cur_bucket) { }
reference
operator*() const
{ return this->m_cur_node->m_v; }
pointer
operator->() const
{ return &this->m_cur_node->m_v; }
hashtable_const_iterator&
operator++()
{
this->incr();
return *this;
}
hashtable_const_iterator
operator++(int)
{
hashtable_const_iterator tmp(*this);
this->incr();
return tmp;
}
};
} // namespace Internal
// ----------------------------------------------------------------------
// Many of class template hashtable's template parameters are policy
// classes. These are defaults for the policies.
namespace Internal
{
// The two key extraction policies used by the *set and *map variants.
template<typename T>
struct identity
{
T
operator()(const T& t) const
{ return t; }
};
template<typename Pair>
struct extract1st
{
typename Pair::first_type
operator()(const Pair& p) const
{ return p.first; }
};
// Default range hashing function: use division to fold a large number
// into the range [0, N).
struct mod_range_hashing
{
typedef std::size_t first_argument_type;
typedef std::size_t second_argument_type;
typedef std::size_t result_type;
result_type
operator() (first_argument_type r, second_argument_type N) const
{ return r % N; }
};
// Default ranged hash function H. In principle it should be a
// function object composed from objects of type H1 and H2 such that
// h(k, N) = h2(h1(k), N), but that would mean making extra copies of
// h1 and h2. So instead we'll just use a tag to tell class template
// hashtable to do that composition.
struct default_ranged_hash { };
// Default value for rehash policy. Bucket size is (usually) the
// smallest prime that keeps the load factor small enough.
struct prime_rehash_policy
{
prime_rehash_policy(float z = 1.0);
float
max_load_factor() const;
// Return a bucket size no smaller than n.
std::size_t
next_bkt(std::size_t n) const;
// Return a bucket count appropriate for n elements
std::size_t
bkt_for_elements(std::size_t n) const;
// n_bkt is current bucket count, n_elt is current element count,
// and n_ins is number of elements to be inserted. Do we need to
// increase bucket count? If so, return make_pair(true, n), where n
// is the new bucket count. If not, return make_pair(false, 0).
std::pair<bool, std::size_t>
need_rehash(std::size_t n_bkt, std::size_t n_elt, std::size_t n_ins) const;
float m_max_load_factor;
float m_growth_factor;
mutable std::size_t m_next_resize;
};
// XXX This is a hack. prime_rehash_policy's member functions, and
// certainly the list of primes, should be defined in a .cc file.
// We're temporarily putting them in a header because we don't have a
// place to put TR1 .cc files yet. There's no good reason for any of
// prime_rehash_policy's member functions to be inline, and there's
// certainly no good reason for X<> to exist at all.
struct lt
{
template<typename X, typename Y>
bool
operator()(X x, Y y)
{ return x < y; }
};
template<int dummy>
struct X
{
static const int n_primes = 256;
static const unsigned long primes[n_primes + 1];
};
template<int dummy>
const int X<dummy>::n_primes;
template<int dummy>
const unsigned long X<dummy>::primes[n_primes + 1] =
{
2ul, 3ul, 5ul, 7ul, 11ul, 13ul, 17ul, 19ul, 23ul, 29ul, 31ul,
37ul, 41ul, 43ul, 47ul, 53ul, 59ul, 61ul, 67ul, 71ul, 73ul, 79ul,
83ul, 89ul, 97ul, 103ul, 109ul, 113ul, 127ul, 137ul, 139ul, 149ul,
157ul, 167ul, 179ul, 193ul, 199ul, 211ul, 227ul, 241ul, 257ul,
277ul, 293ul, 313ul, 337ul, 359ul, 383ul, 409ul, 439ul, 467ul,
503ul, 541ul, 577ul, 619ul, 661ul, 709ul, 761ul, 823ul, 887ul,
953ul, 1031ul, 1109ul, 1193ul, 1289ul, 1381ul, 1493ul, 1613ul,
1741ul, 1879ul, 2029ul, 2179ul, 2357ul, 2549ul, 2753ul, 2971ul,
3209ul, 3469ul, 3739ul, 4027ul, 4349ul, 4703ul, 5087ul, 5503ul,
5953ul, 6427ul, 6949ul, 7517ul, 8123ul, 8783ul, 9497ul, 10273ul,
11113ul, 12011ul, 12983ul, 14033ul, 15173ul, 16411ul, 17749ul,
19183ul, 20753ul, 22447ul, 24281ul, 26267ul, 28411ul, 30727ul,
33223ul, 35933ul, 38873ul, 42043ul, 45481ul, 49201ul, 53201ul,
57557ul, 62233ul, 67307ul, 72817ul, 78779ul, 85229ul, 92203ul,
99733ul, 107897ul, 116731ul, 126271ul, 136607ul, 147793ul,
159871ul, 172933ul, 187091ul, 202409ul, 218971ul, 236897ul,
256279ul, 277261ul, 299951ul, 324503ul, 351061ul, 379787ul,
410857ul, 444487ul, 480881ul, 520241ul, 562841ul, 608903ul,
658753ul, 712697ul, 771049ul, 834181ul, 902483ul, 976369ul,
1056323ul, 1142821ul, 1236397ul, 1337629ul, 1447153ul, 1565659ul,
1693859ul, 1832561ul, 1982627ul, 2144977ul, 2320627ul, 2510653ul,
2716249ul, 2938679ul, 3179303ul, 3439651ul, 3721303ul, 4026031ul,
4355707ul, 4712381ul, 5098259ul, 5515729ul, 5967347ul, 6456007ul,
6984629ul, 7556579ul, 8175383ul, 8844859ul, 9569143ul, 10352717ul,
11200489ul, 12117689ul, 13109983ul, 14183539ul, 15345007ul,
16601593ul, 17961079ul, 19431899ul, 21023161ul, 22744717ul,
24607243ul, 26622317ul, 28802401ul, 31160981ul, 33712729ul,
36473443ul, 39460231ul, 42691603ul, 46187573ul, 49969847ul,
54061849ul, 58488943ul, 63278561ul, 68460391ul, 74066549ul,
80131819ul, 86693767ul, 93793069ul, 101473717ul, 109783337ul,
118773397ul, 128499677ul, 139022417ul, 150406843ul, 162723577ul,
176048909ul, 190465427ul, 206062531ul, 222936881ul, 241193053ul,
260944219ul, 282312799ul, 305431229ul, 330442829ul, 357502601ul,
386778277ul, 418451333ul, 452718089ul, 489790921ul, 529899637ul,
573292817ul, 620239453ul, 671030513ul, 725980837ul, 785430967ul,
849749479ul, 919334987ul, 994618837ul, 1076067617ul, 1164186217ul,
1259520799ul, 1362662261ul, 1474249943ul, 1594975441ul,
1725587117ul, 1866894511ul, 2019773507ul, 2185171673ul,
2364114217ul, 2557710269ul, 2767159799ul, 2993761039ul,
3238918481ul, 3504151727ul, 3791104843ul, 4101556399ul,
4294967291ul,
4294967291ul // sentinel so we don't have to test result of lower_bound
};
inline
prime_rehash_policy::
prime_rehash_policy(float z)
: m_max_load_factor(z), m_growth_factor(2.f), m_next_resize(0)
{ }
inline float
prime_rehash_policy::
max_load_factor() const
{ return m_max_load_factor; }
// Return a prime no smaller than n.
inline std::size_t
prime_rehash_policy::
next_bkt(std::size_t n) const
{
const unsigned long* const last = X<0>::primes + X<0>::n_primes;
const unsigned long* p = std::lower_bound (X<0>::primes, last, n);
m_next_resize = static_cast<std::size_t>(std::ceil(*p * m_max_load_factor));
return *p;
}
// Return the smallest prime p such that alpha p >= n, where alpha
// is the load factor.
inline std::size_t
prime_rehash_policy::
bkt_for_elements(std::size_t n) const
{
const unsigned long* const last = X<0>::primes + X<0>::n_primes;
const float min_bkts = n / m_max_load_factor;
const unsigned long* p = std::lower_bound (X<0>::primes, last,
min_bkts, lt());
m_next_resize = static_cast<std::size_t>(std::ceil(*p * m_max_load_factor));
return *p;
}
// Finds the smallest prime p such that alpha p > n_elt + n_ins.
// If p > n_bkt, return make_pair(true, p); otherwise return
// make_pair(false, 0). In principle this isn't very different from
// bkt_for_elements.
// The only tricky part is that we're caching the element count at
// which we need to rehash, so we don't have to do a floating-point
// multiply for every insertion.
inline std::pair<bool, std::size_t>
prime_rehash_policy::
need_rehash(std::size_t n_bkt, std::size_t n_elt, std::size_t n_ins) const
{
if (n_elt + n_ins > m_next_resize)
{
float min_bkts = (float(n_ins) + float(n_elt)) / m_max_load_factor;
if (min_bkts > n_bkt)
{
min_bkts = std::max (min_bkts, m_growth_factor * n_bkt);
const unsigned long* const last = X<0>::primes + X<0>::n_primes;
const unsigned long* p = std::lower_bound (X<0>::primes, last,
min_bkts, lt());
m_next_resize =
static_cast<std::size_t>(std::ceil(*p * m_max_load_factor));
return std::make_pair(true, *p);
}
else
{
m_next_resize =
static_cast<std::size_t>(std::ceil(n_bkt * m_max_load_factor));
return std::make_pair(false, 0);
}
}
else
return std::make_pair(false, 0);
}
} // namespace Internal
//----------------------------------------------------------------------
// Base classes for std::tr1::hashtable. We define these base classes
// because in some cases we want to do different things depending on
// the value of a policy class. In some cases the policy class affects
// which member functions and nested typedefs are defined; we handle that
// by specializing base class templates. Several of the base class templates
// need to access other members of class template hashtable, so we use
// the "curiously recurring template pattern" for them.
namespace Internal
{
// class template map_base. If the hashtable has a value type of the
// form pair<T1, T2> and a key extraction policy that returns the
// first part of the pair, the hashtable gets a mapped_type typedef.
// If it satisfies those criteria and also has unique keys, then it
// also gets an operator[].
template<typename K, typename V, typename Ex, bool unique, typename Hashtable>
struct map_base { };
template<typename K, typename Pair, typename Hashtable>
struct map_base<K, Pair, extract1st<Pair>, false, Hashtable>
{
typedef typename Pair::second_type mapped_type;
};
template<typename K, typename Pair, typename Hashtable>
struct map_base<K, Pair, extract1st<Pair>, true, Hashtable>
{
typedef typename Pair::second_type mapped_type;
mapped_type&
operator[](const K& k)
{
Hashtable* h = static_cast<Hashtable*>(this);
typename Hashtable::iterator it =
h->insert(std::make_pair(k, mapped_type())).first;
return it->second;
}
};
// class template rehash_base. Give hashtable the max_load_factor
// functions iff the rehash policy is prime_rehash_policy.
template<typename RehashPolicy, typename Hashtable>
struct rehash_base { };
template<typename Hashtable>
struct rehash_base<prime_rehash_policy, Hashtable>
{
float
max_load_factor() const
{
const Hashtable* This = static_cast<const Hashtable*>(this);
return This->rehash_policy()->max_load_factor();
}
void
max_load_factor(float z)
{
Hashtable* This = static_cast<Hashtable*>(this);
This->rehash_policy(prime_rehash_policy(z));
}
};
// Class template hash_code_base. Encapsulates two policy issues that
// aren't quite orthogonal.
// (1) the difference between using a ranged hash function and using
// the combination of a hash function and a range-hashing function.
// In the former case we don't have such things as hash codes, so
// we have a dummy type as placeholder.
// (2) Whether or not we cache hash codes. Caching hash codes is
// meaningless if we have a ranged hash function.
// We also put the key extraction and equality comparison function
// objects here, for convenience.
// Primary template: unused except as a hook for specializations.
template<typename Key, typename Value,
typename ExtractKey, typename Equal,
typename H1, typename H2, typename H,
bool cache_hash_code>
struct hash_code_base;
// Specialization: ranged hash function, no caching hash codes. H1
// and H2 are provided but ignored. We define a dummy hash code type.
template<typename Key, typename Value,
typename ExtractKey, typename Equal,
typename H1, typename H2, typename H>
struct hash_code_base<Key, Value, ExtractKey, Equal, H1, H2, H, false>
{
protected:
hash_code_base(const ExtractKey& ex, const Equal& eq,
const H1&, const H2&, const H& h)
: m_extract(ex), m_eq(eq), m_ranged_hash(h) { }
typedef void* hash_code_t;
hash_code_t
m_hash_code(const Key& k) const
{ return 0; }
std::size_t
bucket_index(const Key& k, hash_code_t, std::size_t N) const
{ return m_ranged_hash (k, N); }
std::size_t
bucket_index(const hash_node<Value, false>* p, std::size_t N) const
{ return m_ranged_hash (m_extract (p->m_v), N); }
bool
compare(const Key& k, hash_code_t, hash_node<Value, false>* n) const
{ return m_eq (k, m_extract(n->m_v)); }
void
store_code(hash_node<Value, false>*, hash_code_t) const
{ }
void
copy_code(hash_node<Value, false>*, const hash_node<Value, false>*) const
{ }
void
m_swap(hash_code_base& x)
{
std::swap(m_extract, x.m_extract);
std::swap(m_eq, x.m_eq);
std::swap(m_ranged_hash, x.m_ranged_hash);
}
protected:
ExtractKey m_extract;
Equal m_eq;
H m_ranged_hash;
};
// No specialization for ranged hash function while caching hash codes.
// That combination is meaningless, and trying to do it is an error.
// Specialization: ranged hash function, cache hash codes. This
// combination is meaningless, so we provide only a declaration
// and no definition.
template<typename Key, typename Value,
typename ExtractKey, typename Equal,
typename H1, typename H2, typename H>
struct hash_code_base<Key, Value, ExtractKey, Equal, H1, H2, H, true>;
// Specialization: hash function and range-hashing function, no
// caching of hash codes. H is provided but ignored. Provides
// typedef and accessor required by TR1.
template<typename Key, typename Value,
typename ExtractKey, typename Equal,
typename H1, typename H2>
struct hash_code_base<Key, Value, ExtractKey, Equal, H1, H2,
default_ranged_hash, false>
{
typedef H1 hasher;
hasher
hash_function() const
{ return m_h1; }
protected:
hash_code_base(const ExtractKey& ex, const Equal& eq,
const H1& h1, const H2& h2, const default_ranged_hash&)
: m_extract(ex), m_eq(eq), m_h1(h1), m_h2(h2) { }
typedef std::size_t hash_code_t;
hash_code_t
m_hash_code(const Key& k) const
{ return m_h1(k); }
std::size_t
bucket_index(const Key&, hash_code_t c, std::size_t N) const
{ return m_h2 (c, N); }
std::size_t
bucket_index(const hash_node<Value, false>* p, std::size_t N) const
{ return m_h2 (m_h1 (m_extract (p->m_v)), N); }
bool
compare(const Key& k, hash_code_t, hash_node<Value, false>* n) const
{ return m_eq (k, m_extract(n->m_v)); }
void
store_code(hash_node<Value, false>*, hash_code_t) const
{ }
void
copy_code(hash_node<Value, false>*, const hash_node<Value, false>*) const
{ }
void
m_swap(hash_code_base& x)
{
std::swap(m_extract, x.m_extract);
std::swap(m_eq, x.m_eq);
std::swap(m_h1, x.m_h1);
std::swap(m_h2, x.m_h2);
}
protected:
ExtractKey m_extract;
Equal m_eq;
H1 m_h1;
H2 m_h2;
};
// Specialization: hash function and range-hashing function,
// caching hash codes. H is provided but ignored. Provides
// typedef and accessor required by TR1.
template<typename Key, typename Value,
typename ExtractKey, typename Equal,
typename H1, typename H2>
struct hash_code_base<Key, Value, ExtractKey, Equal, H1, H2,
default_ranged_hash, true>
{
typedef H1 hasher;
hasher
hash_function() const
{ return m_h1; }
protected:
hash_code_base(const ExtractKey& ex, const Equal& eq,
const H1& h1, const H2& h2, const default_ranged_hash&)
: m_extract(ex), m_eq(eq), m_h1(h1), m_h2(h2) { }
typedef std::size_t hash_code_t;
hash_code_t
m_hash_code (const Key& k) const
{ return m_h1(k); }
std::size_t
bucket_index(const Key&, hash_code_t c, std::size_t N) const
{ return m_h2 (c, N); }
std::size_t
bucket_index(const hash_node<Value, true>* p, std::size_t N) const
{ return m_h2 (p->hash_code, N); }
bool
compare(const Key& k, hash_code_t c, hash_node<Value, true>* n) const
{ return c == n->hash_code && m_eq(k, m_extract(n->m_v)); }
void
store_code(hash_node<Value, true>* n, hash_code_t c) const
{ n->hash_code = c; }
void
copy_code(hash_node<Value, true>* to,
const hash_node<Value, true>* from) const
{ to->hash_code = from->hash_code; }
void
m_swap(hash_code_base& x)
{
std::swap(m_extract, x.m_extract);
std::swap(m_eq, x.m_eq);
std::swap(m_h1, x.m_h1);
std::swap(m_h2, x.m_h2);
}
protected:
ExtractKey m_extract;
Equal m_eq;
H1 m_h1;
H2 m_h2;
};
} // namespace internal
namespace std
{
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 Internal::rehash_base<RehashPolicy,
hashtable<Key, Value, Allocator, ExtractKey,
Equal, H1, H2, H, RehashPolicy,
cache_hash_code, constant_iterators,
unique_keys> >,
public Internal::hash_code_base<Key, Value, ExtractKey, Equal, H1, H2, H,
cache_hash_code>,
public Internal::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 Internal::node_iterator<value_type, constant_iterators,
cache_hash_code>
local_iterator;
typedef Internal::node_const_iterator<value_type, constant_iterators,
cache_hash_code>
const_local_iterator;
typedef Internal::hashtable_iterator<value_type, constant_iterators,
cache_hash_code>
iterator;
typedef Internal::hashtable_const_iterator<value_type, constant_iterators,
cache_hash_code>
const_iterator;
private:
typedef Internal::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;
private:
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&);
public: // 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(); }
public: // 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, this->m_bucket_count);
}
local_iterator
begin(size_type n)
{ return local_iterator(m_buckets[n]); }
local_iterator
end(size_type n)
{ 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 n) 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&);
public: // lookup
iterator
find(const key_type&);
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: // 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 Internal::IF<unique_keys,
std::pair<iterator, bool>, iterator>::type
Insert_Return_Type;
typedef typename Internal::IF<unique_keys,
Internal::extract1st<Insert_Return_Type>,
Internal::identity<Insert_Return_Type>
>::type
Insert_Conv_Type;
node*
find_node(node* p, const key_type& k,
typename hashtable::hash_code_t c) const;
std::pair<iterator, bool>
insert(const value_type&, std::tr1::true_type);
iterator
insert(const value_type&, std::tr1::false_type);
void
erase_node(node*, node**);
public: // Insert and erase
Insert_Return_Type
insert(const value_type& v)
{
return this->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();
public:
// Set number of buckets to be apropriate 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)
: Internal::rehash_base<RP,hashtable>(),
Internal::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>(exk, eq, h1, h2, h),
Internal::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)
: Internal::rehash_base<RP,hashtable>(),
Internal::hash_code_base<K, V, Ex, Eq, H1, H2, H, c> (exk, eq,
h1, h2, h),
Internal::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(Internal::
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)
: Internal::rehash_base<RP, hashtable>(ht),
Internal::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>(ht),
Internal::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_t 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.
Internal::hash_code_base<K, V, Ex, Eq, H1, H2, H, c>::m_swap(x);
// open LWG issue 431
// std::swap(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 = 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 = 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());
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 = 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 = 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>::
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 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>::
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 = find_node(m_buckets[n], k, code))
return std::make_pair(iterator(p, m_buckets + n), false);
std::pair<bool, 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)
{
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 std::make_pair(iterator(new_node, m_buckets + n), true);
}
catch (...)
{
m_deallocate_node (new_node);
__throw_exception_again;
}
}
// 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>::
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);
node* new_node = m_allocate_node (v);
node* prev = find_node(m_buckets[n], k, code);
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>::
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 = Internal::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 i)
{
iterator result = i;
++result;
erase_node(i.m_cur_node, i.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 i)
{
const_iterator result = i;
++result;
erase_node(i.m_cur_node, i.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);
size_type 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* n = *slot;
*slot = n->m_next;
m_deallocate_node (n);
--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>::
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])
{
size_type 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;
}
}
}
} // Namespace std::tr1
#endif /* GNU_LIBSTDCXX_TR1_HASHTABLE_ */
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