include/wx/hash.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/hash.h
   3 // Purpose:     wxHashTable class
   4 // Author:      Julian Smart
   5 // Modified by: VZ at 25.02.00: type safe hashes with WX_DECLARE_HASH()
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_HASH_H__
  13 #define _WX_HASH_H__
  14
  15 #include "wx/defs.h"
  16 #include "wx/string.h"
  17
  18 #define wxUSE_OLD_HASH_TABLE 0
  19
  20 #if !wxUSE_STL
  21     #include "wx/object.h"
  22 #else
  23     class WXDLLIMPEXP_BASE wxObject;
  24 #endif
  25 #if wxUSE_OLD_HASH_TABLE
  26     #include "wx/list.h"
  27 #endif
  28
  29 // the default size of the hash
  30 #define wxHASH_SIZE_DEFAULT     (1000)
  31
  32 /*
  33  * A hash table is an array of user-definable size with lists
  34  * of data items hanging off the array positions.  Usually there'll
  35  * be a hit, so no search is required; otherwise we'll have to run down
  36  * the list to find the desired item.
  37 */
  38
  39 // ----------------------------------------------------------------------------
  40 // this is the base class for object hashes: hash tables which contain
  41 // pointers to objects
  42 // ----------------------------------------------------------------------------
  43
  44 #if wxUSE_OLD_HASH_TABLE
  45
  46 class WXDLLIMPEXP_BASE wxHashTableBase : public wxObject
  47 {
  48 public:
  49     wxHashTableBase();
  50
  51     void Create(wxKeyType keyType = wxKEY_INTEGER,
  52                 size_t size = wxHASH_SIZE_DEFAULT);
  53     void Destroy();
  54
  55     size_t GetSize() const { return m_hashSize; }
  56     size_t GetCount() const { return m_count; }
  57
  58     void DeleteContents(bool flag);
  59
  60 protected:
  61     // find the node for (key, value)
  62     wxNodeBase *GetNode(long key, long value) const;
  63
  64     // the array of lists in which we store the values for given key hash
  65     wxListBase **m_hashTable;
  66
  67     // the size of m_lists array
  68     size_t m_hashSize;
  69
  70     // the type of indexing we use
  71     wxKeyType m_keyType;
  72
  73     // the total number of elements in the hash
  74     size_t m_count;
  75
  76     // should we delete our data?
  77     bool m_deleteContents;
  78
  79 private:
  80     // no copy ctor/assignment operator (yet)
  81     DECLARE_NO_COPY_CLASS(wxHashTableBase)
  82 };
  83
  84 #else // if !wxUSE_OLD_HASH_TABLE
  85
  86 #if !defined(wxENUM_KEY_TYPE_DEFINED)
  87 #define wxENUM_KEY_TYPE_DEFINED
  88
  89 enum wxKeyType
  90 {
  91     wxKEY_NONE,
  92     wxKEY_INTEGER,
  93     wxKEY_STRING
  94 };
  95
  96 #endif
  97
  98 union wxHashKeyValue
  99 {
 100     long integer;
 101     wxChar *string;
 102 };
 103
 104 // for some compilers (AIX xlC), defining it as friend inside the class is not
 105 // enough, so provide a real forward declaration
 106 class WXDLLIMPEXP_BASE wxHashTableBase;
 107
 108 class WXDLLIMPEXP_BASE wxHashTableBase_Node
 109 {
 110     friend class WXDLLIMPEXP_BASE wxHashTableBase;
 111     typedef class WXDLLIMPEXP_BASE wxHashTableBase_Node _Node;
 112 public:
 113     wxHashTableBase_Node( long key, void* value,
 114                           wxHashTableBase* table );
 115     wxHashTableBase_Node( const wxChar* key, void* value,
 116                           wxHashTableBase* table );
 117     ~wxHashTableBase_Node();
 118
 119     long GetKeyInteger() const { return m_key.integer; }
 120     const wxChar* GetKeyString() const { return m_key.string; }
 121
 122     void* GetData() const { return m_value; }
 123     void SetData( void* data ) { m_value = data; }
 124
 125 protected:
 126     _Node* GetNext() const { return m_next; }
 127
 128 protected:
 129     // next node in the chain
 130     wxHashTableBase_Node* m_next;
 131
 132     // key
 133     wxHashKeyValue m_key;
 134
 135     // value
 136     void* m_value;
 137
 138     // pointer to the hash containing the node, used to remove the
 139     // node from the hash when the user deletes the node iterating
 140     // through it
 141     // TODO: move it to wxHashTable_Node (only wxHashTable supports
 142     //       iteration)
 143     wxHashTableBase* m_hashPtr;
 144 };
 145
 146 class WXDLLIMPEXP_BASE wxHashTableBase
 147 #if !wxUSE_STL
 148     : public wxObject
 149 #endif
 150 {
 151     friend class WXDLLIMPEXP_BASE wxHashTableBase_Node;
 152 public:
 153     typedef wxHashTableBase_Node Node;
 154
 155     wxHashTableBase();
 156     virtual ~wxHashTableBase() { };
 157
 158     void Create( wxKeyType keyType = wxKEY_INTEGER,
 159                  size_t size = wxHASH_SIZE_DEFAULT );
 160     void Clear();
 161     void Destroy();
 162
 163     size_t GetSize() const { return m_size; }
 164     size_t GetCount() const { return m_count; }
 165
 166     void DeleteContents( bool flag ) { m_deleteContents = flag; }
 167
 168     static long MakeKey(const wxChar *string);
 169
 170 protected:
 171     void DoPut( long key, long hash, void* data );
 172     void DoPut( const wxChar* key, long hash, void* data );
 173     void* DoGet( long key, long hash ) const;
 174     void* DoGet( const wxChar* key, long hash ) const;
 175     void* DoDelete( long key, long hash );
 176     void* DoDelete( const wxChar* key, long hash );
 177
 178 private:
 179     // Remove the node from the hash, *only called from
 180     // ~wxHashTable*_Node destructor
 181     void DoRemoveNode( wxHashTableBase_Node* node );
 182
 183     // destroys data contained in the node if appropriate:
 184     // deletes the key if it is a string and destrys
 185     // the value if m_deleteContents is true
 186     void DoDestroyNode( wxHashTableBase_Node* node );
 187
 188     // inserts a node in the table (at the end of the chain)
 189     void DoInsertNode( size_t bucket, wxHashTableBase_Node* node );
 190
 191     // removes a node from the table (fiven a pointer to the previous
 192     // but does not delete it (only deletes its contents)
 193     void DoUnlinkNode( size_t bucket, wxHashTableBase_Node* node,
 194                        wxHashTableBase_Node* prev );
 195
 196     // unconditionally deletes node value (invoking the
 197     // correct destructor)
 198     virtual void DoDeleteContents( wxHashTableBase_Node* node ) = 0;
 199
 200 protected:
 201     // number of buckets
 202     size_t m_size;
 203
 204     // number of nodes (key/value pairs)
 205     size_t m_count;
 206
 207     // table
 208     Node** m_table;
 209
 210     // key typ (INTEGER/STRING)
 211     wxKeyType m_keyType;
 212
 213     // delete contents when hash is cleared
 214     bool m_deleteContents;
 215
 216 private:
 217     DECLARE_NO_COPY_CLASS(wxHashTableBase)
 218 };
 219
 220 #endif // wxUSE_OLD_HASH_TABLE
 221
 222 // ----------------------------------------------------------------------------
 223 // for compatibility only
 224 // ----------------------------------------------------------------------------
 225
 226 #if !wxUSE_OLD_HASH_TABLE
 227
 228 class WXDLLIMPEXP_BASE wxHashTable_Node : public wxHashTableBase_Node
 229 {
 230     friend class WXDLLIMPEXP_BASE wxHashTable;
 231 public:
 232     wxHashTable_Node( long key, void* value,
 233                       wxHashTableBase* table )
 234         : wxHashTableBase_Node( key, value, table ) { }
 235     wxHashTable_Node( const wxChar* key, void* value,
 236                       wxHashTableBase* table )
 237         : wxHashTableBase_Node( key, value, table ) { }
 238
 239     wxObject* GetData() const
 240         { return (wxObject*)wxHashTableBase_Node::GetData(); }
 241     void SetData( wxObject* data )
 242         { wxHashTableBase_Node::SetData( data ); }
 243
 244     wxHashTable_Node* GetNext() const
 245         { return (wxHashTable_Node*)wxHashTableBase_Node::GetNext(); }
 246 };
 247
 248 // should inherit protectedly, but it is public for compatibility in
 249 // order to publicly inherit from wxObject
 250 class WXDLLIMPEXP_BASE wxHashTable : public wxHashTableBase
 251 {
 252     typedef wxHashTableBase hash;
 253 public:
 254     typedef wxHashTable_Node Node;
 255     typedef wxHashTable_Node* compatibility_iterator;
 256 public:
 257     wxHashTable( wxKeyType keyType = wxKEY_INTEGER,
 258                  size_t size = wxHASH_SIZE_DEFAULT )
 259         : wxHashTableBase() { Create( keyType, size ); BeginFind(); }
 260     wxHashTable( const wxHashTable& table );
 261
 262     virtual ~wxHashTable() { Destroy(); }
 263
 264     const wxHashTable& operator=( const wxHashTable& );
 265
 266     // key and value are the same
 267     void Put(long value, wxObject *object)
 268         { DoPut( value, value, object ); }
 269     void Put(long lhash, long value, wxObject *object)
 270         { DoPut( value, lhash, object ); }
 271     void Put(const wxChar *value, wxObject *object)
 272         { DoPut( value, MakeKey( value ), object ); }
 273     // FIXME-UTF8: have only wxString forms here
 274     void Put(const wxString& value, wxObject *object)
 275         { DoPut( value, MakeKey( value ), object ); }
 276     void Put(long lhash, const wxChar *value, wxObject *object)
 277         { DoPut( value, lhash, object ); }
 278
 279     // key and value are the same
 280     wxObject *Get(long value) const
 281         { return (wxObject*)DoGet( value, value ); }
 282     wxObject *Get(long lhash, long value) const
 283         { return (wxObject*)DoGet( value, lhash ); }
 284     wxObject *Get(const wxChar *value) const
 285         { return (wxObject*)DoGet( value, MakeKey( value ) ); }
 286     // FIXME-UTF8: have only wxString forms here
 287     wxObject *Get(const wxString& value) const
 288         { return (wxObject*)DoGet( value, MakeKey( value ) ); }
 289     wxObject *Get(long lhash, const wxChar *value) const
 290         { return (wxObject*)DoGet( value, lhash ); }
 291
 292     // Deletes entry and returns data if found
 293     wxObject *Delete(long key)
 294         { return (wxObject*)DoDelete( key, key ); }
 295     wxObject *Delete(long lhash, long key)
 296         { return (wxObject*)DoDelete( key, lhash ); }
 297     wxObject *Delete(const wxChar *key)
 298         { return (wxObject*)DoDelete( key, MakeKey( key ) ); }
 299     // FIXME-UTF8: have only wxString forms here
 300     wxObject *Delete(const wxString& key)
 301         { return (wxObject*)DoDelete( key, MakeKey( key ) ); }
 302     wxObject *Delete(long lhash, const wxChar *key)
 303         { return (wxObject*)DoDelete( key, lhash ); }
 304
 305     // Construct your own integer key from a string, e.g. in case
 306     // you need to combine it with something
 307     long MakeKey(const wxChar *string) const
 308         { return wxHashTableBase::MakeKey(string); }
 309
 310     // Way of iterating through whole hash table (e.g. to delete everything)
 311     // Not necessary, of course, if you're only storing pointers to
 312     // objects maintained separately
 313     void BeginFind() { m_curr = NULL; m_currBucket = 0; }
 314     Node* Next();
 315
 316     void Clear() { wxHashTableBase::Clear(); }
 317
 318     size_t GetCount() const { return wxHashTableBase::GetCount(); }
 319 protected:
 320     // copy helper
 321     void DoCopy( const wxHashTable& copy );
 322
 323     // searches the next node starting from bucket bucketStart and sets
 324     // m_curr to it and m_currBucket to its bucket
 325     void GetNextNode( size_t bucketStart );
 326 private:
 327     virtual void DoDeleteContents( wxHashTableBase_Node* node );
 328
 329     // current node
 330     Node* m_curr;
 331
 332     // bucket the current node belongs to
 333     size_t m_currBucket;
 334 };
 335
 336 #else // if wxUSE_OLD_HASH_TABLE
 337
 338 class WXDLLIMPEXP_BASE wxHashTable : public wxObject
 339 {
 340 public:
 341     typedef wxNode Node;
 342     typedef wxNode* compatibility_iterator;
 343
 344     int n;
 345     int current_position;
 346     wxNode *current_node;
 347
 348     unsigned int key_type;
 349     wxList **hash_table;
 350
 351     wxHashTable(int the_key_type = wxKEY_INTEGER,
 352                 int size = wxHASH_SIZE_DEFAULT);
 353     virtual ~wxHashTable();
 354
 355     // copy ctor and assignment operator
 356     wxHashTable(const wxHashTable& table) : wxObject()
 357         { DoCopy(table); }
 358     wxHashTable& operator=(const wxHashTable& table)
 359         { Clear(); DoCopy(table); return *this; }
 360
 361     void DoCopy(const wxHashTable& table);
 362
 363     void Destroy();
 364
 365     bool Create(int the_key_type = wxKEY_INTEGER,
 366                 int size = wxHASH_SIZE_DEFAULT);
 367
 368     // Note that there are 2 forms of Put, Get.
 369     // With a key and a value, the *value* will be checked
 370     // when a collision is detected. Otherwise, if there are
 371     // 2 items with a different value but the same key,
 372     // we'll retrieve the WRONG ONE. So where possible,
 373     // supply the required value along with the key.
 374     // In fact, the value-only versions make a key, and still store
 375     // the value. The use of an explicit key might be required
 376     // e.g. when combining several values into one key.
 377     // When doing that, it's highly likely we'll get a collision,
 378     // e.g. 1 + 2 = 3, 2 + 1 = 3.
 379
 380     // key and value are NOT necessarily the same
 381     void Put(long key, long value, wxObject *object);
 382     void Put(long key, const wxChar *value, wxObject *object);
 383
 384     // key and value are the same
 385     void Put(long value, wxObject *object);
 386     void Put(const wxChar *value, wxObject *object);
 387
 388     // key and value not the same
 389     wxObject *Get(long key, long value) const;
 390     wxObject *Get(long key, const wxChar *value) const;
 391
 392     // key and value are the same
 393     wxObject *Get(long value) const;
 394     wxObject *Get(const wxChar *value) const;
 395
 396     // Deletes entry and returns data if found
 397     wxObject *Delete(long key);
 398     wxObject *Delete(const wxChar *key);
 399
 400     wxObject *Delete(long key, int value);
 401     wxObject *Delete(long key, const wxChar *value);
 402
 403     // Construct your own integer key from a string, e.g. in case
 404     // you need to combine it with something
 405     long MakeKey(const wxChar *string) const;
 406
 407     // Way of iterating through whole hash table (e.g. to delete everything)
 408     // Not necessary, of course, if you're only storing pointers to
 409     // objects maintained separately
 410
 411     void BeginFind();
 412     Node* Next();
 413
 414     void DeleteContents(bool flag);
 415     void Clear();
 416
 417     // Returns number of nodes
 418     size_t GetCount() const { return m_count; }
 419
 420 private:
 421     size_t m_count;             // number of elements in the hashtable
 422     bool m_deleteContents;
 423
 424     DECLARE_DYNAMIC_CLASS(wxHashTable)
 425 };
 426
 427 #endif // wxUSE_OLD_HASH_TABLE
 428
 429 #if !wxUSE_OLD_HASH_TABLE
 430
 431 // defines a new type safe hash table which stores the elements of type eltype
 432 // in lists of class listclass
 433 #define _WX_DECLARE_HASH(eltype, dummy, hashclass, classexp)                  \
 434     classexp hashclass : public wxHashTableBase                               \
 435     {                                                                         \
 436     public:                                                                   \
 437         hashclass(wxKeyType keyType = wxKEY_INTEGER,                          \
 438                   size_t size = wxHASH_SIZE_DEFAULT)                          \
 439             : wxHashTableBase() { Create(keyType, size); }                    \
 440                                                                               \
 441         virtual ~hashclass() { Destroy(); }                                   \
 442                                                                               \
 443         void Put(long key, eltype *data) { DoPut(key, key, (void*)data); }    \
 444         void Put(long lhash, long key, eltype *data)                          \
 445             { DoPut(key, lhash, (void*)data); }                               \
 446         eltype *Get(long key) const { return (eltype*)DoGet(key, key); }      \
 447         eltype *Get(long lhash, long key) const                               \
 448             { return (eltype*)DoGet(key, lhash); }                            \
 449         eltype *Delete(long key) { return (eltype*)DoDelete(key, key); }      \
 450         eltype *Delete(long lhash, long key)                                  \
 451             { return (eltype*)DoDelete(key, lhash); }                         \
 452     private:                                                                  \
 453         virtual void DoDeleteContents( wxHashTableBase_Node* node )           \
 454             { delete (eltype*)node->GetData(); }                              \
 455                                                                               \
 456         DECLARE_NO_COPY_CLASS(hashclass)                                      \
 457     }
 458
 459 #else // if wxUSE_OLD_HASH_TABLE
 460
 461 #define _WX_DECLARE_HASH(eltype, listclass, hashclass, classexp)               \
 462     classexp hashclass : public wxHashTableBase                                \
 463     {                                                                          \
 464     public:                                                                    \
 465         hashclass(wxKeyType keyType = wxKEY_INTEGER,                           \
 466                   size_t size = wxHASH_SIZE_DEFAULT)                           \
 467             { Create(keyType, size); }                                         \
 468                                                                                \
 469         virtual ~hashclass() { Destroy(); }                                            \
 470                                                                                \
 471         void Put(long key, long val, eltype *data) { DoPut(key, val, data); }  \
 472         void Put(long key, eltype *data) { DoPut(key, key, data); }            \
 473                                                                                \
 474         eltype *Get(long key, long value) const                                \
 475         {                                                                      \
 476             wxNodeBase *node = GetNode(key, value);                            \
 477             return node ? ((listclass::Node *)node)->GetData() : (eltype *)0;  \
 478         }                                                                      \
 479         eltype *Get(long key) const { return Get(key, key); }                  \
 480                                                                                \
 481         eltype *Delete(long key, long value)                                   \
 482         {                                                                      \
 483             eltype *data;                                                      \
 484                                                                                \
 485             wxNodeBase *node = GetNode(key, value);                            \
 486             if ( node )                                                        \
 487             {                                                                  \
 488                 data = ((listclass::Node *)node)->GetData();                   \
 489                                                                                \
 490                 delete node;                                                   \
 491                 m_count--;                                                     \
 492             }                                                                  \
 493             else                                                               \
 494             {                                                                  \
 495                 data = (eltype *)0;                                            \
 496             }                                                                  \
 497                                                                                \
 498             return data;                                                       \
 499         }                                                                      \
 500         eltype *Delete(long key) { return Delete(key, key); }                  \
 501                                                                                \
 502     protected:                                                                 \
 503         void DoPut(long key, long value, eltype *data)                         \
 504         {                                                                      \
 505             size_t slot = (size_t)abs((int)(key % (long)m_hashSize));          \
 506                                                                                \
 507             if ( !m_hashTable[slot] )                                          \
 508             {                                                                  \
 509                 m_hashTable[slot] = new listclass(m_keyType);                  \
 510                 if ( m_deleteContents )                                        \
 511                     m_hashTable[slot]->DeleteContents(true);                   \
 512             }                                                                  \
 513                                                                                \
 514             ((listclass *)m_hashTable[slot])->Append(value, data);             \
 515             m_count++;                                                         \
 516         }                                                                      \
 517                                                                                \
 518         DECLARE_NO_COPY_CLASS(hashclass)                                       \
 519     }
 520
 521 #endif // wxUSE_OLD_HASH_TABLE
 522
 523 // this macro is to be used in the user code
 524 #define WX_DECLARE_HASH(el, list, hash) \
 525     _WX_DECLARE_HASH(el, list, hash, class)
 526
 527 // and this one does exactly the same thing but should be used inside the
 528 // library
 529 #define WX_DECLARE_EXPORTED_HASH(el, list, hash)  \
 530     _WX_DECLARE_HASH(el, list, hash, class WXDLLEXPORT)
 531
 532 #define WX_DECLARE_USER_EXPORTED_HASH(el, list, hash, usergoo)  \
 533     _WX_DECLARE_HASH(el, list, hash, class usergoo)
 534
 535 // delete all hash elements
 536 //
 537 // NB: the class declaration of the hash elements must be visible from the
 538 //     place where you use this macro, otherwise the proper destructor may not
 539 //     be called (a decent compiler should give a warning about it, but don't
 540 //     count on it)!
 541 #define WX_CLEAR_HASH_TABLE(hash)                                            \
 542     {                                                                        \
 543         (hash).BeginFind();                                                  \
 544         wxHashTable::compatibility_iterator it = (hash).Next();              \
 545         while( it )                                                          \
 546         {                                                                    \
 547             delete it->GetData();                                            \
 548             it = (hash).Next();                                              \
 549         }                                                                    \
 550         (hash).Clear();                                                      \
 551     }
 552
 553 #endif
 554     // _WX_HASH_H__