include/wx/hashmap.h

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