1// -*- C++ -*-
2
3// Copyright (C) 2005-2015 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the terms
7// of the GNU General Public License as published by the Free Software
8// Foundation; either version 3, or (at your option) any later
9// version.
10
11// This library is distributed in the hope that it will be useful, but
12// WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14// General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26
27// Permission to use, copy, modify, sell, and distribute this software
28// is hereby granted without fee, provided that the above copyright
29// notice appears in all copies, and that both that copyright notice
30// and this permission notice appear in supporting documentation. None
31// of the above authors, nor IBM Haifa Research Laboratories, make any
32// representation about the suitability of this software for any
33// purpose. It is provided "as is" without express or implied
34// warranty.
35
36/**
37 * @file ranged_hash_fn.hpp
38 * Contains a unified ranged hash functor, allowing the hash tables
39 * to deal with a single class for ranged hashing.
40 */
41
42#ifndef PB_DS_RANGED_HASH_FN_HPP
43#define PB_DS_RANGED_HASH_FN_HPP
44
45#include <utility>
46#include <debug/debug.h>
47
48namespace __gnu_pbds
49{
50  namespace detail
51  {
52    /// Primary template.
53    template<typename Key, typename Hash_Fn, typename _Alloc,
54	     typename Comb_Hash_Fn, bool Store_Hash>
55    class ranged_hash_fn;
56
57#define PB_DS_CLASS_T_DEC \
58    template<typename Key, typename Hash_Fn, typename _Alloc, \
59	     typename Comb_Hash_Fn>
60
61#define PB_DS_CLASS_C_DEC \
62    ranged_hash_fn<Key,	Hash_Fn, _Alloc, Comb_Hash_Fn, false>
63
64    /**
65     * Specialization 1
66     * The client supplies a hash function and a ranged hash function,
67     * and requests that hash values not be stored.
68     **/
69    template<typename Key, typename Hash_Fn, typename _Alloc,
70	     typename Comb_Hash_Fn>
71    class ranged_hash_fn< Key, Hash_Fn, _Alloc, Comb_Hash_Fn, false>
72    : public Hash_Fn, public Comb_Hash_Fn
73    {
74    protected:
75      typedef typename _Alloc::size_type size_type;
76      typedef Hash_Fn hash_fn_base;
77      typedef Comb_Hash_Fn comb_hash_fn_base;
78      typedef typename _Alloc::template rebind< Key>::other key_allocator;
79      typedef typename key_allocator::const_reference key_const_reference;
80
81      ranged_hash_fn(size_type);
82
83      ranged_hash_fn(size_type, const Hash_Fn&);
84
85      ranged_hash_fn(size_type, const Hash_Fn&, const Comb_Hash_Fn&);
86
87      void
88      swap(PB_DS_CLASS_C_DEC&);
89
90      void
91      notify_resized(size_type);
92
93      inline size_type
94      operator()(key_const_reference) const;
95    };
96
97    PB_DS_CLASS_T_DEC
98    PB_DS_CLASS_C_DEC::
99    ranged_hash_fn(size_type size)
100    { Comb_Hash_Fn::notify_resized(size); }
101
102    PB_DS_CLASS_T_DEC
103    PB_DS_CLASS_C_DEC::
104    ranged_hash_fn(size_type size, const Hash_Fn& r_hash_fn)
105    : Hash_Fn(r_hash_fn)
106    { Comb_Hash_Fn::notify_resized(size); }
107
108    PB_DS_CLASS_T_DEC
109    PB_DS_CLASS_C_DEC::
110    ranged_hash_fn(size_type size, const Hash_Fn& r_hash_fn,
111		   const Comb_Hash_Fn& r_comb_hash_fn)
112    : Hash_Fn(r_hash_fn), Comb_Hash_Fn(r_comb_hash_fn)
113    { comb_hash_fn_base::notify_resized(size); }
114
115    PB_DS_CLASS_T_DEC
116    void
117    PB_DS_CLASS_C_DEC::
118    swap(PB_DS_CLASS_C_DEC& other)
119    {
120      comb_hash_fn_base::swap(other);
121      std::swap((Hash_Fn& )(*this), (Hash_Fn& )other);
122    }
123
124    PB_DS_CLASS_T_DEC
125    void
126    PB_DS_CLASS_C_DEC::
127    notify_resized(size_type size)
128    { comb_hash_fn_base::notify_resized(size); }
129
130    PB_DS_CLASS_T_DEC
131    inline typename PB_DS_CLASS_C_DEC::size_type
132    PB_DS_CLASS_C_DEC::
133    operator()(key_const_reference r_key) const
134    { return (comb_hash_fn_base::operator()(hash_fn_base::operator()(r_key)));}
135
136#undef PB_DS_CLASS_T_DEC
137#undef PB_DS_CLASS_C_DEC
138
139#define PB_DS_CLASS_T_DEC \
140    template<typename Key, typename Hash_Fn, typename _Alloc, \
141	     typename Comb_Hash_Fn>
142
143#define PB_DS_CLASS_C_DEC \
144    ranged_hash_fn<Key,Hash_Fn,	_Alloc, Comb_Hash_Fn, true>
145
146    /**
147     * Specialization 2
148     * The client supplies a hash function and a ranged hash function,
149     * and requests that hash values be stored.
150     **/
151    template<typename Key, typename Hash_Fn, typename _Alloc,
152	     typename Comb_Hash_Fn>
153    class ranged_hash_fn<Key, Hash_Fn, _Alloc, Comb_Hash_Fn, true>
154    : public Hash_Fn, public Comb_Hash_Fn
155    {
156    protected:
157      typedef typename _Alloc::size_type size_type;
158      typedef std::pair<size_type, size_type> comp_hash;
159      typedef Hash_Fn hash_fn_base;
160      typedef Comb_Hash_Fn comb_hash_fn_base;
161      typedef typename _Alloc::template rebind<Key>::other key_allocator;
162      typedef typename key_allocator::const_reference key_const_reference;
163
164      ranged_hash_fn(size_type);
165
166      ranged_hash_fn(size_type, const Hash_Fn&);
167
168      ranged_hash_fn(size_type, const Hash_Fn&, const Comb_Hash_Fn&);
169
170      void
171      swap(PB_DS_CLASS_C_DEC&);
172
173      void
174      notify_resized(size_type);
175
176      inline comp_hash
177      operator()(key_const_reference) const;
178
179      inline comp_hash
180      operator()(key_const_reference, size_type) const;
181    };
182
183    PB_DS_CLASS_T_DEC
184    PB_DS_CLASS_C_DEC::
185    ranged_hash_fn(size_type size)
186    { Comb_Hash_Fn::notify_resized(size); }
187
188    PB_DS_CLASS_T_DEC
189    PB_DS_CLASS_C_DEC::
190    ranged_hash_fn(size_type size, const Hash_Fn& r_hash_fn) :
191      Hash_Fn(r_hash_fn)
192    { Comb_Hash_Fn::notify_resized(size); }
193
194    PB_DS_CLASS_T_DEC
195    PB_DS_CLASS_C_DEC::
196    ranged_hash_fn(size_type size, const Hash_Fn& r_hash_fn,
197		   const Comb_Hash_Fn& r_comb_hash_fn)
198    : Hash_Fn(r_hash_fn), Comb_Hash_Fn(r_comb_hash_fn)
199    { comb_hash_fn_base::notify_resized(size); }
200
201    PB_DS_CLASS_T_DEC
202    void
203    PB_DS_CLASS_C_DEC::
204    swap(PB_DS_CLASS_C_DEC& other)
205    {
206      comb_hash_fn_base::swap(other);
207      std::swap((Hash_Fn& )(*this), (Hash_Fn& )other);
208    }
209
210    PB_DS_CLASS_T_DEC
211    void
212    PB_DS_CLASS_C_DEC::
213    notify_resized(size_type size)
214    { comb_hash_fn_base::notify_resized(size); }
215
216    PB_DS_CLASS_T_DEC
217    inline typename PB_DS_CLASS_C_DEC::comp_hash
218    PB_DS_CLASS_C_DEC::
219    operator()(key_const_reference r_key) const
220    {
221      const size_type hash = hash_fn_base::operator()(r_key);
222      return std::make_pair(comb_hash_fn_base::operator()(hash), hash);
223    }
224
225    PB_DS_CLASS_T_DEC
226    inline typename PB_DS_CLASS_C_DEC::comp_hash
227    PB_DS_CLASS_C_DEC::
228    operator()
229#ifdef _GLIBCXX_DEBUG
230      (key_const_reference r_key, size_type hash) const
231#else
232      (key_const_reference /*r_key*/, size_type hash) const
233#endif
234    {
235      _GLIBCXX_DEBUG_ASSERT(hash == hash_fn_base::operator()(r_key));
236      return std::make_pair(comb_hash_fn_base::operator()(hash), hash);
237    }
238
239#undef PB_DS_CLASS_T_DEC
240#undef PB_DS_CLASS_C_DEC
241
242#define PB_DS_CLASS_T_DEC \
243    template<typename Key, typename _Alloc, typename Comb_Hash_Fn>
244
245#define PB_DS_CLASS_C_DEC \
246    ranged_hash_fn<Key,	null_type, _Alloc, Comb_Hash_Fn, false>
247
248    /**
249     * Specialization 3
250     * The client does not supply a hash function (by specifying
251     * null_type as the Hash_Fn parameter), and requests that hash
252     * values not be stored.
253     **/
254    template<typename Key, typename _Alloc, typename Comb_Hash_Fn>
255    class ranged_hash_fn<Key, null_type, _Alloc, Comb_Hash_Fn, false>
256    : public Comb_Hash_Fn
257    {
258    protected:
259      typedef typename _Alloc::size_type size_type;
260      typedef Comb_Hash_Fn comb_hash_fn_base;
261
262      ranged_hash_fn(size_type);
263
264      ranged_hash_fn(size_type, const Comb_Hash_Fn&);
265
266      ranged_hash_fn(size_type, const null_type&, const Comb_Hash_Fn&);
267
268      void
269      swap(PB_DS_CLASS_C_DEC&);
270    };
271
272    PB_DS_CLASS_T_DEC
273    PB_DS_CLASS_C_DEC::
274    ranged_hash_fn(size_type size)
275    { Comb_Hash_Fn::notify_resized(size); }
276
277    PB_DS_CLASS_T_DEC
278    PB_DS_CLASS_C_DEC::
279    ranged_hash_fn(size_type size, const Comb_Hash_Fn& r_comb_hash_fn) :
280      Comb_Hash_Fn(r_comb_hash_fn)
281    { }
282
283    PB_DS_CLASS_T_DEC
284    PB_DS_CLASS_C_DEC::
285    ranged_hash_fn(size_type size, const null_type& r_null_type,
286		   const Comb_Hash_Fn& r_comb_hash_fn)
287    : Comb_Hash_Fn(r_comb_hash_fn)
288    { }
289
290    PB_DS_CLASS_T_DEC
291    void
292    PB_DS_CLASS_C_DEC::
293    swap(PB_DS_CLASS_C_DEC& other)
294    { comb_hash_fn_base::swap(other); }
295
296#undef PB_DS_CLASS_T_DEC
297#undef PB_DS_CLASS_C_DEC
298
299#define PB_DS_CLASS_T_DEC \
300    template<typename Key, typename _Alloc, typename Comb_Hash_Fn>
301
302#define PB_DS_CLASS_C_DEC \
303    ranged_hash_fn<Key,	null_type, _Alloc, Comb_Hash_Fn, true>
304
305    /**
306     * Specialization 4
307     * The client does not supply a hash function (by specifying
308     * null_type as the Hash_Fn parameter), and requests that hash
309     * values be stored.
310     **/
311    template<typename Key, typename _Alloc, typename Comb_Hash_Fn>
312    class ranged_hash_fn<Key, null_type, _Alloc, Comb_Hash_Fn, true>
313    : public Comb_Hash_Fn
314    {
315    protected:
316      typedef typename _Alloc::size_type size_type;
317      typedef Comb_Hash_Fn comb_hash_fn_base;
318
319      ranged_hash_fn(size_type);
320
321      ranged_hash_fn(size_type, const Comb_Hash_Fn&);
322
323      ranged_hash_fn(size_type, const null_type&, const Comb_Hash_Fn&);
324
325      void
326      swap(PB_DS_CLASS_C_DEC&);
327    };
328
329    PB_DS_CLASS_T_DEC
330    PB_DS_CLASS_C_DEC::
331    ranged_hash_fn(size_type size)
332    { Comb_Hash_Fn::notify_resized(size); }
333
334    PB_DS_CLASS_T_DEC
335    PB_DS_CLASS_C_DEC::
336    ranged_hash_fn(size_type size, const Comb_Hash_Fn& r_comb_hash_fn)
337    : Comb_Hash_Fn(r_comb_hash_fn)
338    { }
339
340    PB_DS_CLASS_T_DEC
341    PB_DS_CLASS_C_DEC::
342    ranged_hash_fn(size_type size, const null_type& r_null_type,
343		   const Comb_Hash_Fn& r_comb_hash_fn)
344    : Comb_Hash_Fn(r_comb_hash_fn)
345    { }
346
347    PB_DS_CLASS_T_DEC
348    void
349    PB_DS_CLASS_C_DEC::
350    swap(PB_DS_CLASS_C_DEC& other)
351    { comb_hash_fn_base::swap(other); }
352
353#undef PB_DS_CLASS_T_DEC
354#undef PB_DS_CLASS_C_DEC
355
356  } // namespace detail
357} // namespace __gnu_pbds
358
359#endif
360