1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: wxHashMap class
4 // Author: Mattia Barbon
8 // Copyright: (c) Mattia Barbon
9 // Licence: wxWindows licence
10 /////////////////////////////////////////////////////////////////////////////
12 #ifndef _WX_HASHMAP_H_
13 #define _WX_HASHMAP_H_
15 #if defined(__GNUG__) && !defined(__APPLE__)
16 #pragma interface "hashmap.h"
19 #include "wx/string.h"
21 #include <stddef.h> // for ptrdiff_t
24 struct WXDLLIMPEXP_BASE _wxHashTable_NodeBase
26 _wxHashTable_NodeBase() : m_nxt(0) {}
28 _wxHashTable_NodeBase
* m_nxt
;
31 // DECLARE_NO_COPY_CLASS(_wxHashTable_NodeBase)
32 // without rewriting the macros, which require a public copy constructor.
36 class WXDLLIMPEXP_BASE _wxHashTableBase2
39 typedef void (*NodeDtor
)(_wxHashTable_NodeBase
*);
40 typedef unsigned long (*BucketFromNode
)(_wxHashTableBase2
*,_wxHashTable_NodeBase
*);
41 typedef _wxHashTable_NodeBase
* (*ProcessNode
)(_wxHashTable_NodeBase
*);
43 static _wxHashTable_NodeBase
* DummyProcessNode(_wxHashTable_NodeBase
* node
);
44 static void DeleteNodes( size_t buckets
, _wxHashTable_NodeBase
** table
,
46 static _wxHashTable_NodeBase
* GetFirstNode( size_t buckets
,
47 _wxHashTable_NodeBase
** table
)
49 for( size_t i
= 0; i
< buckets
; ++i
)
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
];
59 // returns the first prime in ms_primes greater than n
60 static unsigned long GetNextPrime( unsigned long n
);
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
);
66 static void CopyHashTable( _wxHashTable_NodeBase
** srcTable
,
67 size_t srcBuckets
, _wxHashTableBase2
* dst
,
68 _wxHashTable_NodeBase
** dstTable
,
69 BucketFromNode func
, ProcessNode proc
);
71 static void** AllocTable( size_t sz
)
73 return (void **)calloc(sz
, sizeof(void*));
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 \
81 typedef KEY_T key_type; \
82 typedef VALUE_T value_type; \
83 typedef HASH_T hasher; \
84 typedef KEY_EQ_T key_equal; \
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; \
97 typedef KEY_EX_T key_extractor; \
98 typedef CLASSNAME Self; \
101 size_t m_tableBuckets; \
104 key_equal m_equals; \
105 key_extractor m_getKey; \
107 struct Node:public _wxHashTable_NodeBase \
110 Node( const value_type& value ) \
111 : m_value( value ) {} \
112 Node* m_next() { return (Node*)this->m_nxt; } \
114 value_type m_value; \
118 friend struct Iterator; \
120 static void DeleteNode( _wxHashTable_NodeBase* node ) \
122 delete (Node*)node; \
126 /* forward iterator */ \
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; } \
141 Node* GetNextNode() \
143 size_type bucket = GetBucketForNode(m_ht,m_node); \
144 for( size_type i = bucket + 1; i < m_ht->m_tableBuckets; ++i ) \
146 if( m_ht->m_table[i] ) \
147 return m_ht->m_table[i]; \
154 Node* next = m_node->m_next(); \
155 m_node = next ? next : GetNextNode(); \
160 struct iterator:public Iterator \
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); } \
170 struct const_iterator:public Iterator \
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); } \
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 ) ), \
190 m_table = (Node**)AllocTable( m_tableBuckets ); \
193 CLASSNAME( const Self& ht ) \
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 ) \
204 const Self& operator=( const Self& ht ) \
207 m_hasher = ht.m_hasher; \
208 m_equals = ht.m_equals; \
209 m_getKey = ht.m_getKey; \
210 m_items = ht.m_items; \
222 hasher hash_funct() { return m_hasher; } \
223 key_equal key_eq() { return m_equals; } \
225 /* removes all elements from the hash table, but does not */ \
226 /* shrink it ( perhaps it should ) */ \
229 DeleteNodes( m_tableBuckets, (_wxHashTable_NodeBase**)m_table, \
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; } \
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 ); }; \
243 { return iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
245 size_type erase( const const_key_type& key ) \
247 Node** node = GetNodePtr( key ); \
253 Node* temp = (*node)->m_next(); \
256 if( SHOULD_SHRINK( m_tableBuckets, m_items ) ) \
257 ResizeTable( GetPreviousPrime( (unsigned long) m_tableBuckets ) - 1 ); \
262 static size_type GetBucketForNode( Self* ht, Node* node ) \
264 return ht->m_hasher( ht->m_getKey( node->m_value ) ) \
265 % ht->m_tableBuckets; \
267 static Node* CopyNode( Node* node ) { return new Node( *node ); } \
269 Node* GetOrCreateNode( const value_type& value ) \
271 const const_key_type& key = m_getKey( value ); \
272 size_t bucket = m_hasher( key ) % m_tableBuckets; \
273 Node* node = m_table[bucket]; \
277 if( m_equals( m_getKey( node->m_value ), key ) ) \
279 node = node->m_next(); \
281 return CreateNode( value , bucket); \
283 Node * CreateNode( const value_type& value, size_t bucket ) \
285 Node* node = new Node( value ); \
286 node->m_nxt = m_table[bucket]; \
287 m_table[bucket] = node; \
289 /* must be after the node is inserted */ \
291 if( SHOULD_GROW( m_tableBuckets, m_items ) ) \
292 ResizeTable( m_tableBuckets ); \
296 void CreateNode( const value_type& value ) \
298 CreateNode(value, m_hasher( m_getKey(value) ) % m_tableBuckets ); \
301 /* returns NULL if not found */ \
302 Node** GetNodePtr( const const_key_type& key ) const \
304 unsigned long hash = m_hasher( key ); \
305 Node** node = &m_table[hash % m_tableBuckets]; \
309 if( m_equals( m_getKey( (*node)->m_value ), key ) ) \
311 node = (Node**)&(*node)->m_nxt; \
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 \
321 unsigned long hash = m_hasher( key ); \
322 Node* node = m_table[hash % m_tableBuckets]; \
326 if( m_equals( m_getKey( node->m_value ), key ) ) \
328 node = node->m_next(); \
334 void ResizeTable( size_t newSize ) \
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; \
342 CopyHashTable( (_wxHashTable_NodeBase**)srcTable, srcBuckets, \
343 this, (_wxHashTable_NodeBase**)m_table, \
344 (BucketFromNode)GetBucketForNode,\
345 (ProcessNode)&DummyProcessNode ); \
349 /* this must be called _after_ m_table has been cleaned */ \
350 void HashCopy( const Self& ht ) \
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 ); \
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 ) \
368 typedef VALUE_T t2; \
369 typedef const KEY_T const_t1; \
370 typedef const VALUE_T const_t2; \
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()) {} \
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 ) \
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; \
392 const_key_reference operator()( const_pair_reference pair ) const { return pair.first; }\
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; } \
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
)
405 return float(items
)/float(buckets
) >= 0.85;
408 // ----------------------------------------------------------------------------
409 // hashing and comparison functors
410 // ----------------------------------------------------------------------------
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)
417 class WXDLLIMPEXP_BASE 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
; }
428 wxIntegerHash
& operator=(const wxIntegerHash
&) { return *this; }
431 class WXDLLIMPEXP_BASE 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
; }
442 wxIntegerEqual
& operator=(const wxIntegerEqual
&) { return *this; }
446 class WXDLLIMPEXP_BASE wxPointerHash
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
); }
455 wxPointerHash
& operator=(const wxPointerHash
&) { return *this; }
458 class WXDLLIMPEXP_BASE wxPointerEqual
462 bool operator()( const void* a
, const void* b
) const { return a
== b
; }
464 wxPointerEqual
& operator=(const wxPointerEqual
&) { return *this; }
467 // wxString, char*, wxChar*
468 class WXDLLIMPEXP_BASE 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
* );
478 unsigned long operator()( const char* x
) const
479 { return charStringHash( x
); }
480 static unsigned long charStringHash( const char* );
481 #endif // wxUSE_UNICODE
483 wxStringHash
& operator=(const wxStringHash
&) { return *this; }
486 class WXDLLIMPEXP_BASE wxStringEqual
490 bool operator()( const wxString
& a
, const wxString
& b
) const
492 bool operator()( const wxChar
* a
, const wxChar
* b
) const
493 { return wxStrcmp( a
, b
) == 0; }
495 bool operator()( const char* a
, const char* b
) const
496 { return strcmp( a
, b
) == 0; }
497 #endif // wxUSE_UNICODE
499 wxStringEqual
& operator=(const wxStringEqual
&) { return *this; }
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 \
509 typedef VALUE_T mapped_type; \
511 CLASSNAME( size_type hint = 100, hasher hf = hasher(), key_equal eq = key_equal() ) \
512 : CLASSNAME##_wxImplementation_HashTable( hint, hf, eq, CLASSNAME##_wxImplementation_KeyEx() ) {} \
514 mapped_type& operator[]( const const_key_type& key ) \
516 return GetOrCreateNode( CLASSNAME##_wxImplementation_Pair( key ) )->m_value.second; \
519 const_iterator find( const const_key_type& key ) const \
521 return const_iterator( GetNode( key ), this ); \
524 iterator find( const const_key_type& key ) \
526 return iterator( GetNode( key ), this ); \
529 void insert( const value_type& v ) { (*this)[v.first] = v.second; } \
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 ); } \
536 /* count() == 0 | 1 */ \
537 size_type count( const const_key_type& key ) \
538 { return GetNode( key ) ? 1 : 0; } \
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 )
545 #define WX_DECLARE_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
546 _WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
549 #define WX_DECLARE_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
550 _WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
553 // and these do exactly the same thing but should be used inside the
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 )
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 )
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 )
566 // delete all hash elements
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
572 #define WX_CLEAR_HASH_MAP(type, hashmap) \
574 type##::iterator it, en; \
575 for( it = (hashmap).begin(), en = (hashmap).end(); it != en; ++it ) \
580 #endif // _WX_HASHMAP_H_