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1 /////////////////////////////////////////////////////////////////////////////
2 // Name: hashmap.h
3 // Purpose: wxHashMap class
4 // Author: Mattia Barbon
5 // Modified by:
6 // Created: 29/01/2002
7 // RCS-ID: $Id$
8 // Copyright: (c) Mattia Barbon
9 // Licence: wxWindows licence
10 /////////////////////////////////////////////////////////////////////////////
11
12 #ifndef _WX_HASHMAP_H_
13 #define _WX_HASHMAP_H_
14
15 #if defined(__GNUG__) && !defined(__APPLE__)
16 #pragma interface "hashmap.h"
17 #endif
18
19 #include "wx/string.h"
20
21 #include <stddef.h> // for ptrdiff_t
22
23 // private
24 struct WXDLLIMPEXP_BASE _wxHashTable_NodeBase
25 {
26 _wxHashTable_NodeBase() : m_nxt(0) {}
27
28 _wxHashTable_NodeBase* m_nxt;
29
30 // Cannot do this:
31 // DECLARE_NO_COPY_CLASS(_wxHashTable_NodeBase)
32 // without rewriting the macros, which require a public copy constructor.
33 };
34
35 // private
36 class WXDLLIMPEXP_BASE _wxHashTableBase2
37 {
38 public:
39 typedef void (*NodeDtor)(_wxHashTable_NodeBase*);
40 typedef unsigned long (*BucketFromNode)(_wxHashTableBase2*,_wxHashTable_NodeBase*);
41 typedef _wxHashTable_NodeBase* (*ProcessNode)(_wxHashTable_NodeBase*);
42 protected:
43 static _wxHashTable_NodeBase* DummyProcessNode(_wxHashTable_NodeBase* node);
44 static void DeleteNodes( size_t buckets, _wxHashTable_NodeBase** table,
45 NodeDtor dtor );
46 static _wxHashTable_NodeBase* GetFirstNode( size_t buckets,
47 _wxHashTable_NodeBase** table )
48 {
49 for( size_t i = 0; i < buckets; ++i )
50 if( table[i] )
51 return table[i];
52 return 0;
53 }
54
55 // as static const unsigned prime_count = 31 but works with all compilers
56 enum { prime_count = 31 };
57 static const unsigned long ms_primes[prime_count];
58
59 // returns the first prime in ms_primes greater than n
60 static unsigned long GetNextPrime( unsigned long n );
61
62 // returns the first prime in ms_primes smaller than n
63 // ( or ms_primes[0] if n is very small )
64 static unsigned long GetPreviousPrime( unsigned long n );
65
66 static void CopyHashTable( _wxHashTable_NodeBase** srcTable,
67 size_t srcBuckets, _wxHashTableBase2* dst,
68 _wxHashTable_NodeBase** dstTable,
69 BucketFromNode func, ProcessNode proc );
70
71 static void** AllocTable( size_t sz )
72 {
73 return (void **)calloc(sz, sizeof(void*));
74 }
75 };
76
77 #define _WX_DECLARE_HASHTABLE( VALUE_T, KEY_T, HASH_T, KEY_EX_T, KEY_EQ_T, CLASSNAME, CLASSEXP, SHOULD_GROW, SHOULD_SHRINK ) \
78 CLASSEXP CLASSNAME : protected _wxHashTableBase2 \
79 { \
80 public: \
81 typedef KEY_T key_type; \
82 typedef VALUE_T value_type; \
83 typedef HASH_T hasher; \
84 typedef KEY_EQ_T key_equal; \
85 \
86 typedef size_t size_type; \
87 typedef ptrdiff_t difference_type; \
88 typedef value_type* pointer; \
89 typedef const value_type* const_pointer; \
90 typedef value_type& reference; \
91 typedef const value_type& const_reference; \
92 /* should these be protected? */ \
93 typedef const KEY_T const_key_type; \
94 typedef const VALUE_T const_mapped_type; \
95 public: \
96 struct Node; \
97 typedef KEY_EX_T key_extractor; \
98 typedef CLASSNAME Self; \
99 protected: \
100 Node** m_table; \
101 size_t m_tableBuckets; \
102 size_t m_items; \
103 hasher m_hasher; \
104 key_equal m_equals; \
105 key_extractor m_getKey; \
106 public: \
107 struct Node:public _wxHashTable_NodeBase \
108 { \
109 public: \
110 Node( const value_type& value ) \
111 : m_value( value ) {} \
112 Node* m_next() { return (Node*)this->m_nxt; } \
113 \
114 value_type m_value; \
115 }; \
116 \
117 struct Iterator; \
118 friend struct Iterator; \
119 protected: \
120 static void DeleteNode( _wxHashTable_NodeBase* node ) \
121 { \
122 delete (Node*)node; \
123 } \
124 public: \
125 /* */ \
126 /* forward iterator */ \
127 /* */ \
128 struct Iterator \
129 { \
130 Node* m_node; \
131 Self* m_ht; \
132 \
133 Iterator() : m_node(0), m_ht(0) {} \
134 Iterator( Node* node, const Self* ht ) \
135 : m_node(node), m_ht((Self*)ht) {} \
136 bool operator ==( const Iterator& it ) const \
137 { return m_node == it.m_node; } \
138 bool operator !=( const Iterator& it ) const \
139 { return m_node != it.m_node; } \
140 protected: \
141 Node* GetNextNode() \
142 { \
143 size_type bucket = GetBucketForNode(m_ht,m_node); \
144 for( size_type i = bucket + 1; i < m_ht->m_tableBuckets; ++i ) \
145 { \
146 if( m_ht->m_table[i] ) \
147 return m_ht->m_table[i]; \
148 } \
149 return 0; \
150 } \
151 \
152 void PlusPlus() \
153 { \
154 Node* next = m_node->m_next(); \
155 m_node = next ? next : GetNextNode(); \
156 } \
157 }; \
158 \
159 public: \
160 struct iterator:public Iterator \
161 { \
162 iterator() : Iterator() {} \
163 iterator( Node* node, Self* ht ) : Iterator( node, ht ) {} \
164 iterator& operator++() { PlusPlus(); return *this; } \
165 iterator operator++(int) { iterator it=*this;PlusPlus();return it; } \
166 reference operator *() const { return m_node->m_value; } \
167 pointer operator ->() const { return &(m_node->m_value); } \
168 }; \
169 \
170 struct const_iterator:public Iterator \
171 { \
172 const_iterator() : Iterator() {} \
173 const_iterator( Node* node, const Self* ht ) \
174 : Iterator( node, (Self*)ht ) {} \
175 const_iterator& operator++() { PlusPlus();return *this; } \
176 const_iterator operator++(int) { const_iterator it=*this;PlusPlus();return it; } \
177 const_reference operator *() const { return m_node->m_value; } \
178 const_pointer operator ->() const { return &(m_node->m_value); } \
179 }; \
180 \
181 CLASSNAME( size_type sz = 10, const hasher& hfun = hasher(), \
182 const key_equal& k_eq = key_equal(), \
183 const key_extractor& k_ex = key_extractor() ) \
184 : m_tableBuckets( GetNextPrime( (unsigned long) sz ) ), \
185 m_items( 0 ), \
186 m_hasher( hfun ), \
187 m_equals( k_eq ), \
188 m_getKey( k_ex ) \
189 { \
190 m_table = (Node**)AllocTable( m_tableBuckets ); \
191 } \
192 \
193 CLASSNAME( const Self& ht ) \
194 : m_table( 0 ), \
195 m_tableBuckets( 0 ), \
196 m_items( ht.m_items ), \
197 m_hasher( ht.m_hasher ), \
198 m_equals( ht.m_equals ), \
199 m_getKey( ht.m_getKey ) \
200 { \
201 HashCopy( ht ); \
202 } \
203 \
204 const Self& operator=( const Self& ht ) \
205 { \
206 clear(); \
207 m_hasher = ht.m_hasher; \
208 m_equals = ht.m_equals; \
209 m_getKey = ht.m_getKey; \
210 m_items = ht.m_items; \
211 HashCopy( ht ); \
212 return *this; \
213 } \
214 \
215 ~CLASSNAME() \
216 { \
217 clear(); \
218 \
219 free(m_table); \
220 } \
221 \
222 hasher hash_funct() { return m_hasher; } \
223 key_equal key_eq() { return m_equals; } \
224 \
225 /* removes all elements from the hash table, but does not */ \
226 /* shrink it ( perhaps it should ) */ \
227 void clear() \
228 { \
229 DeleteNodes( m_tableBuckets, (_wxHashTable_NodeBase**)m_table, \
230 DeleteNode ); \
231 m_items = 0; \
232 } \
233 \
234 size_type size() const { return m_items; } \
235 size_type max_size() const { return size_type(-1); } \
236 bool empty() const { return size() == 0; } \
237 \
238 const_iterator end() const { return const_iterator( 0, this ); } \
239 iterator end() { return iterator( 0, this ); } \
240 const_iterator begin() const \
241 { return const_iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
242 iterator begin() \
243 { return iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
244 \
245 size_type erase( const const_key_type& key ) \
246 { \
247 Node** node = GetNodePtr( key ); \
248 \
249 if( !node ) \
250 return 0; \
251 \
252 --m_items; \
253 Node* temp = (*node)->m_next(); \
254 delete *node; \
255 (*node) = temp; \
256 if( SHOULD_SHRINK( m_tableBuckets, m_items ) ) \
257 ResizeTable( GetPreviousPrime( (unsigned long) m_tableBuckets ) - 1 ); \
258 return 1; \
259 } \
260 \
261 protected: \
262 static size_type GetBucketForNode( Self* ht, Node* node ) \
263 { \
264 return ht->m_hasher( ht->m_getKey( node->m_value ) ) \
265 % ht->m_tableBuckets; \
266 } \
267 static Node* CopyNode( Node* node ) { return new Node( *node ); } \
268 \
269 Node* GetOrCreateNode( const value_type& value ) \
270 { \
271 const const_key_type& key = m_getKey( value ); \
272 size_t bucket = m_hasher( key ) % m_tableBuckets; \
273 Node* node = m_table[bucket]; \
274 \
275 while( node ) \
276 { \
277 if( m_equals( m_getKey( node->m_value ), key ) ) \
278 return node; \
279 node = node->m_next(); \
280 } \
281 return CreateNode( value , bucket); \
282 }\
283 Node * CreateNode( const value_type& value, size_t bucket ) \
284 {\
285 Node* node = new Node( value ); \
286 node->m_nxt = m_table[bucket]; \
287 m_table[bucket] = node; \
288 \
289 /* must be after the node is inserted */ \
290 ++m_items; \
291 if( SHOULD_GROW( m_tableBuckets, m_items ) ) \
292 ResizeTable( m_tableBuckets ); \
293 \
294 return node; \
295 } \
296 void CreateNode( const value_type& value ) \
297 {\
298 CreateNode(value, m_hasher( m_getKey(value) ) % m_tableBuckets ); \
299 }\
300 \
301 /* returns NULL if not found */ \
302 Node** GetNodePtr( const const_key_type& key ) const \
303 { \
304 unsigned long hash = m_hasher( key ); \
305 Node** node = &m_table[hash % m_tableBuckets]; \
306 \
307 while( *node ) \
308 { \
309 if( m_equals( m_getKey( (*node)->m_value ), key ) ) \
310 return node; \
311 node = (Node**)&(*node)->m_nxt; \
312 } \
313 \
314 return 0; \
315 } \
316 \
317 /* returns NULL if not found */ \
318 /* expressing it in terms of GetNodePtr is 5-8% slower :-( */ \
319 Node* GetNode( const const_key_type& key ) const \
320 { \
321 unsigned long hash = m_hasher( key ); \
322 Node* node = m_table[hash % m_tableBuckets]; \
323 \
324 while( node ) \
325 { \
326 if( m_equals( m_getKey( node->m_value ), key ) ) \
327 return node; \
328 node = node->m_next(); \
329 } \
330 \
331 return 0; \
332 } \
333 \
334 void ResizeTable( size_t newSize ) \
335 { \
336 newSize = GetNextPrime( (unsigned long)newSize ); \
337 Node** srcTable = m_table; \
338 size_t srcBuckets = m_tableBuckets; \
339 m_table = (Node**)AllocTable( newSize ); \
340 m_tableBuckets = newSize; \
341 \
342 CopyHashTable( (_wxHashTable_NodeBase**)srcTable, srcBuckets, \
343 this, (_wxHashTable_NodeBase**)m_table, \
344 (BucketFromNode)GetBucketForNode,\
345 (ProcessNode)&DummyProcessNode ); \
346 free(srcTable); \
347 } \
348 \
349 /* this must be called _after_ m_table has been cleaned */ \
350 void HashCopy( const Self& ht ) \
351 { \
352 ResizeTable( ht.size() ); \
353 CopyHashTable( (_wxHashTable_NodeBase**)ht.m_table, ht.m_tableBuckets,\
354 (_wxHashTableBase2*)this, \
355 (_wxHashTable_NodeBase**)m_table, \
356 (BucketFromNode)GetBucketForNode, \
357 (ProcessNode)CopyNode ); \
358 } \
359 };
360
361 // defines an STL-like pair class CLASSNAME storing two fields: first of type
362 // KEY_T and second of type VALUE_T
363 #define _WX_DECLARE_PAIR( KEY_T, VALUE_T, CLASSNAME, CLASSEXP ) \
364 CLASSEXP CLASSNAME \
365 { \
366 public: \
367 typedef KEY_T t1; \
368 typedef VALUE_T t2; \
369 typedef const KEY_T const_t1; \
370 typedef const VALUE_T const_t2; \
371 \
372 CLASSNAME( const const_t1& f, const const_t2& s ):first(t1(f)),second(t2(s)) {} \
373 CLASSNAME( const const_t1& f ):first(t1(f)),second(t2()) {} \
374 \
375 t1 first; \
376 t2 second; \
377 };
378
379 // defines the class CLASSNAME returning the key part (of type KEY_T) from a
380 // pair of type PAIR_T
381 #define _WX_DECLARE_HASH_MAP_KEY_EX( KEY_T, PAIR_T, CLASSNAME, CLASSEXP ) \
382 CLASSEXP CLASSNAME \
383 { \
384 typedef KEY_T key_type; \
385 typedef PAIR_T pair_type; \
386 typedef const key_type const_key_type; \
387 typedef const pair_type const_pair_type; \
388 typedef const_key_type& const_key_reference; \
389 typedef const_pair_type& const_pair_reference; \
390 public: \
391 CLASSNAME() { } \
392 const_key_reference operator()( const_pair_reference pair ) const { return pair.first; }\
393 \
394 /* the dummy assignment operator is needed to suppress compiler */ \
395 /* warnings from hash table class' operator=(): gcc complains about */ \
396 /* "statement with no effect" without it */ \
397 CLASSNAME& operator=(const CLASSNAME&) { return *this; } \
398 };
399
400 // grow/shrink predicates
401 inline bool never_grow( size_t, size_t ) { return FALSE; }
402 inline bool never_shrink( size_t, size_t ) { return FALSE; }
403 inline bool grow_lf70( size_t buckets, size_t items )
404 {
405 return float(items)/float(buckets) >= 0.85;
406 }
407
408 // ----------------------------------------------------------------------------
409 // hashing and comparison functors
410 // ----------------------------------------------------------------------------
411
412 // NB: implementation detail: all of these classes must have dummy assignment
413 // operators to suppress warnings about "statement with no effect" from gcc
414 // in the hash table class assignment operator (where they're assigned)
415
416 // integer types
417 class WXDLLIMPEXP_BASE wxIntegerHash
418 {
419 public:
420 wxIntegerHash() { }
421 unsigned long operator()( long x ) const { return (unsigned long)x; }
422 unsigned long operator()( unsigned long x ) const { return x; }
423 unsigned long operator()( int x ) const { return (unsigned long)x; }
424 unsigned long operator()( unsigned int x ) const { return x; }
425 unsigned long operator()( short x ) const { return (unsigned long)x; }
426 unsigned long operator()( unsigned short x ) const { return x; }
427
428 wxIntegerHash& operator=(const wxIntegerHash&) { return *this; }
429 };
430
431 class WXDLLIMPEXP_BASE wxIntegerEqual
432 {
433 public:
434 wxIntegerEqual() { }
435 bool operator()( long a, long b ) const { return a == b; }
436 bool operator()( unsigned long a, unsigned long b ) const { return a == b; }
437 bool operator()( int a, int b ) const { return a == b; }
438 bool operator()( unsigned int a, unsigned int b ) const { return a == b; }
439 bool operator()( short a, short b ) const { return a == b; }
440 bool operator()( unsigned short a, unsigned short b ) const { return a == b; }
441
442 wxIntegerEqual& operator=(const wxIntegerEqual&) { return *this; }
443 };
444
445 // pointers
446 class WXDLLIMPEXP_BASE wxPointerHash
447 {
448 public:
449 wxPointerHash() { }
450
451 // TODO: this might not work well on architectures with 64 bit pointers but
452 // 32 bit longs, we should use % ULONG_MAX there
453 unsigned long operator()( const void* k ) const { return (unsigned long)wxPtrToULong(k); }
454
455 wxPointerHash& operator=(const wxPointerHash&) { return *this; }
456 };
457
458 class WXDLLIMPEXP_BASE wxPointerEqual
459 {
460 public:
461 wxPointerEqual() { }
462 bool operator()( const void* a, const void* b ) const { return a == b; }
463
464 wxPointerEqual& operator=(const wxPointerEqual&) { return *this; }
465 };
466
467 // wxString, char*, wxChar*
468 class WXDLLIMPEXP_BASE wxStringHash
469 {
470 public:
471 wxStringHash() {}
472 unsigned long operator()( const wxString& x ) const
473 { return wxCharStringHash( x.c_str() ); }
474 unsigned long operator()( const wxChar* x ) const
475 { return wxCharStringHash( x ); }
476 static unsigned long wxCharStringHash( const wxChar* );
477 #if wxUSE_UNICODE
478 unsigned long operator()( const char* x ) const
479 { return charStringHash( x ); }
480 static unsigned long charStringHash( const char* );
481 #endif // wxUSE_UNICODE
482
483 wxStringHash& operator=(const wxStringHash&) { return *this; }
484 };
485
486 class WXDLLIMPEXP_BASE wxStringEqual
487 {
488 public:
489 wxStringEqual() {}
490 bool operator()( const wxString& a, const wxString& b ) const
491 { return a == b; }
492 bool operator()( const wxChar* a, const wxChar* b ) const
493 { return wxStrcmp( a, b ) == 0; }
494 #if wxUSE_UNICODE
495 bool operator()( const char* a, const char* b ) const
496 { return strcmp( a, b ) == 0; }
497 #endif // wxUSE_UNICODE
498
499 wxStringEqual& operator=(const wxStringEqual&) { return *this; }
500 };
501
502 #define _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, CLASSEXP ) \
503 _WX_DECLARE_PAIR( KEY_T, VALUE_T, CLASSNAME##_wxImplementation_Pair, CLASSEXP ) \
504 _WX_DECLARE_HASH_MAP_KEY_EX( KEY_T, CLASSNAME##_wxImplementation_Pair, CLASSNAME##_wxImplementation_KeyEx, CLASSEXP ) \
505 _WX_DECLARE_HASHTABLE( CLASSNAME##_wxImplementation_Pair, KEY_T, HASH_T, CLASSNAME##_wxImplementation_KeyEx, KEY_EQ_T, CLASSNAME##_wxImplementation_HashTable, CLASSEXP, grow_lf70, never_shrink ) \
506 CLASSEXP CLASSNAME:public CLASSNAME##_wxImplementation_HashTable \
507 { \
508 public: \
509 typedef VALUE_T mapped_type; \
510 \
511 CLASSNAME( size_type hint = 100, hasher hf = hasher(), key_equal eq = key_equal() ) \
512 : CLASSNAME##_wxImplementation_HashTable( hint, hf, eq, CLASSNAME##_wxImplementation_KeyEx() ) {} \
513 \
514 mapped_type& operator[]( const const_key_type& key ) \
515 { \
516 return GetOrCreateNode( CLASSNAME##_wxImplementation_Pair( key ) )->m_value.second; \
517 } \
518 \
519 const_iterator find( const const_key_type& key ) const \
520 { \
521 return const_iterator( GetNode( key ), this ); \
522 } \
523 \
524 iterator find( const const_key_type& key ) \
525 { \
526 return iterator( GetNode( key ), this ); \
527 } \
528 \
529 void insert( const value_type& v ) { (*this)[v.first] = v.second; } \
530 \
531 size_type erase( const key_type& k ) \
532 { return CLASSNAME##_wxImplementation_HashTable::erase( k ); } \
533 void erase( const iterator& it ) { erase( it->first ); } \
534 void erase( const const_iterator& it ) { erase( it->first ); } \
535 \
536 /* count() == 0 | 1 */ \
537 size_type count( const const_key_type& key ) \
538 { return GetNode( key ) ? 1 : 0; } \
539 }
540
541 // these macros are to be used in the user code
542 #define WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
543 _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, class )
544
545 #define WX_DECLARE_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
546 _WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
547 CLASSNAME, class )
548
549 #define WX_DECLARE_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
550 _WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
551 CLASSNAME, class )
552
553 // and these do exactly the same thing but should be used inside the
554 // library
555 #define WX_DECLARE_EXPORTED_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
556 _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, class WXDLLEXPORT )
557
558 #define WX_DECLARE_EXPORTED_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
559 _WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
560 CLASSNAME, class WXDLLEXPORT )
561
562 #define WX_DECLARE_EXPORTED_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
563 _WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
564 CLASSNAME, class WXDLLEXPORT )
565
566 // delete all hash elements
567 //
568 // NB: the class declaration of the hash elements must be visible from the
569 // place where you use this macro, otherwise the proper destructor may not
570 // be called (a decent compiler should give a warning about it, but don't
571 // count on it)!
572 #define WX_CLEAR_HASH_MAP(type, hashmap) \
573 { \
574 type##::iterator it, en; \
575 for( it = (hashmap).begin(), en = (hashmap).end(); it != en; ++it ) \
576 delete it->second; \
577 (hashmap).clear(); \
578 }
579
580 #endif // _WX_HASHMAP_H_
581