1 // -*- C++ -*-
2 
3 // Copyright (C) 2005, 2006, 2009, 2011 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 
48 namespace __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