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)
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_HASH_H__
  13 #define _WX_HASH_H__
  14
  15 #if defined(__GNUG__) && !defined(__APPLE__)
  16 #pragma interface "hash.h"
  17 #endif
  18
  19 #include "wx/list.h"
  20 #include "wx/dynarray.h"
  21
  22 // the default size of the hash
  23 #define wxHASH_SIZE_DEFAULT     (1000)
  24
  25 /*
  26  * A hash table is an array of user-definable size with lists
  27  * of data items hanging off the array positions.  Usually there'll
  28  * be a hit, so no search is required; otherwise we'll have to run down
  29  * the list to find the desired item.
  30 */
  31
  32 // ----------------------------------------------------------------------------
  33 // this is the base class for object hashes: hash tables which contain
  34 // pointers to objects
  35 // ----------------------------------------------------------------------------
  36
  37 class WXDLLIMPEXP_BASE wxHashTableBase : public wxObject
  38 {
  39 public:
  40     wxHashTableBase();
  41
  42     void Create(wxKeyType keyType = wxKEY_INTEGER,
  43                 size_t size = wxHASH_SIZE_DEFAULT);
  44     void Destroy();
  45
  46     size_t GetSize() const { return m_hashSize; }
  47     size_t GetCount() const { return m_count; }
  48
  49     void DeleteContents(bool flag);
  50
  51 protected:
  52     // find the node for (key, value)
  53     wxNodeBase *GetNode(long key, long value) const;
  54
  55     // the array of lists in which we store the values for given key hash
  56     wxListBase **m_hashTable;
  57
  58     // the size of m_lists array
  59     size_t m_hashSize;
  60
  61     // the type of indexing we use
  62     wxKeyType m_keyType;
  63
  64     // the total number of elements in the hash
  65     size_t m_count;
  66
  67     // should we delete our data?
  68     bool m_deleteContents;
  69
  70 private:
  71     // no copy ctor/assignment operator (yet)
  72     DECLARE_NO_COPY_CLASS(wxHashTableBase)
  73 };
  74
  75 #if WXWIN_COMPATIBILITY_2_4
  76
  77 // ----------------------------------------------------------------------------
  78 // a hash table which stores longs
  79 // ----------------------------------------------------------------------------
  80
  81 class WXDLLIMPEXP_BASE wxHashTableLong : public wxObject
  82 {
  83 public:
  84     wxHashTableLong(size_t size = wxHASH_SIZE_DEFAULT)
  85         { Init(size); }
  86     virtual ~wxHashTableLong();
  87
  88     void Create(size_t size = wxHASH_SIZE_DEFAULT);
  89     void Destroy();
  90
  91     size_t GetSize() const { return m_hashSize; }
  92     size_t GetCount() const { return m_count; }
  93
  94     void Put(long key, long value);
  95     long Get(long key) const;
  96     long Delete(long key);
  97
  98 protected:
  99     void Init(size_t size);
 100
 101 private:
 102     wxArrayLong **m_values,
 103                 **m_keys;
 104
 105     // the size of array above
 106     size_t m_hashSize;
 107
 108     // the total number of elements in the hash
 109     size_t m_count;
 110
 111     // not implemented yet
 112     DECLARE_NO_COPY_CLASS(wxHashTableLong)
 113 };
 114
 115 // ----------------------------------------------------------------------------
 116 // wxStringHashTable: a hash table which indexes strings with longs
 117 // ----------------------------------------------------------------------------
 118
 119 class WXDLLIMPEXP_BASE wxStringHashTable : public wxObject
 120 {
 121 public:
 122     wxStringHashTable(size_t sizeTable = wxHASH_SIZE_DEFAULT);
 123     virtual ~wxStringHashTable();
 124
 125     // add a string associated with this key to the table
 126     void Put(long key, const wxString& value);
 127
 128     // get the string from the key: if not found, an empty string is returned
 129     // and the wasFound is set to FALSE if not NULL
 130     wxString Get(long key, bool *wasFound = NULL) const;
 131
 132     // remove the item, returning TRUE if the item was found and deleted
 133     bool Delete(long key) const;
 134
 135     // clean up
 136     void Destroy();
 137
 138 private:
 139     wxArrayLong **m_keys;
 140     wxArrayString **m_values;
 141
 142     // the size of array above
 143     size_t m_hashSize;
 144
 145     DECLARE_NO_COPY_CLASS(wxStringHashTable)
 146 };
 147
 148 #endif
 149
 150 // ----------------------------------------------------------------------------
 151 // for compatibility only
 152 // ----------------------------------------------------------------------------
 153
 154 class WXDLLIMPEXP_BASE wxHashTable : public wxObject
 155 {
 156 public:
 157     int n;
 158     int current_position;
 159     wxNode *current_node;
 160
 161     unsigned int key_type;
 162     wxList **hash_table;
 163
 164     wxHashTable(int the_key_type = wxKEY_INTEGER,
 165                 int size = wxHASH_SIZE_DEFAULT);
 166     ~wxHashTable();
 167
 168     // copy ctor and assignment operator
 169     wxHashTable(const wxHashTable& table) : wxObject()
 170         { DoCopy(table); }
 171     wxHashTable& operator=(const wxHashTable& table)
 172         { Clear(); DoCopy(table); return *this; }
 173
 174     void DoCopy(const wxHashTable& table);
 175
 176     void Destroy();
 177
 178     bool Create(int the_key_type = wxKEY_INTEGER,
 179                 int size = wxHASH_SIZE_DEFAULT);
 180
 181     // Note that there are 2 forms of Put, Get.
 182     // With a key and a value, the *value* will be checked
 183     // when a collision is detected. Otherwise, if there are
 184     // 2 items with a different value but the same key,
 185     // we'll retrieve the WRONG ONE. So where possible,
 186     // supply the required value along with the key.
 187     // In fact, the value-only versions make a key, and still store
 188     // the value. The use of an explicit key might be required
 189     // e.g. when combining several values into one key.
 190     // When doing that, it's highly likely we'll get a collision,
 191     // e.g. 1 + 2 = 3, 2 + 1 = 3.
 192
 193     // key and value are NOT necessarily the same
 194     void Put(long key, long value, wxObject *object);
 195     void Put(long key, const wxChar *value, wxObject *object);
 196
 197     // key and value are the same
 198     void Put(long value, wxObject *object);
 199     void Put(const wxChar *value, wxObject *object);
 200
 201     // key and value not the same
 202     wxObject *Get(long key, long value) const;
 203     wxObject *Get(long key, const wxChar *value) const;
 204
 205     // key and value are the same
 206     wxObject *Get(long value) const;
 207     wxObject *Get(const wxChar *value) const;
 208
 209     // Deletes entry and returns data if found
 210     wxObject *Delete(long key);
 211     wxObject *Delete(const wxChar *key);
 212
 213     wxObject *Delete(long key, int value);
 214     wxObject *Delete(long key, const wxChar *value);
 215
 216     // Construct your own integer key from a string, e.g. in case
 217     // you need to combine it with something
 218     long MakeKey(const wxChar *string) const;
 219
 220     // Way of iterating through whole hash table (e.g. to delete everything)
 221     // Not necessary, of course, if you're only storing pointers to
 222     // objects maintained separately
 223
 224     void BeginFind();
 225     wxNode *Next();
 226
 227     void DeleteContents(bool flag);
 228     void Clear();
 229
 230     // Returns number of nodes
 231     size_t GetCount() const { return m_count; }
 232
 233 private:
 234     size_t m_count;             // number of elements in the hashtable
 235     bool m_deleteContents;
 236
 237     DECLARE_DYNAMIC_CLASS(wxHashTable)
 238 };
 239
 240 // defines a new type safe hash table which stores the elements of type eltype
 241 // in lists of class listclass
 242 #define _WX_DECLARE_HASH(eltype, listclass, hashclass, classexp)               \
 243     classexp hashclass : public wxHashTableBase                                \
 244     {                                                                          \
 245     public:                                                                    \
 246         hashclass(wxKeyType keyType = wxKEY_INTEGER,                           \
 247                   size_t size = wxHASH_SIZE_DEFAULT)                           \
 248             { Create(keyType, size); }                                         \
 249                                                                                \
 250         ~hashclass() { Destroy(); }                                            \
 251                                                                                \
 252         void Put(long key, long val, eltype *data) { DoPut(key, val, data); }  \
 253         void Put(long key, eltype *data) { DoPut(key, key, data); }            \
 254                                                                                \
 255         eltype *Get(long key, long value) const                                \
 256         {                                                                      \
 257             wxNodeBase *node = GetNode(key, value);                            \
 258             return node ? ((listclass::Node *)node)->GetData() : (eltype *)0;  \
 259         }                                                                      \
 260         eltype *Get(long key) const { return Get(key, key); }                  \
 261                                                                                \
 262         eltype *Delete(long key, long value)                                   \
 263         {                                                                      \
 264             eltype *data;                                                      \
 265                                                                                \
 266             wxNodeBase *node = GetNode(key, value);                            \
 267             if ( node )                                                        \
 268             {                                                                  \
 269                 data = ((listclass::Node *)node)->GetData();                   \
 270                                                                                \
 271                 delete node;                                                   \
 272                 m_count--;                                                     \
 273             }                                                                  \
 274             else                                                               \
 275             {                                                                  \
 276                 data = (eltype *)0;                                            \
 277             }                                                                  \
 278                                                                                \
 279             return data;                                                       \
 280         }                                                                      \
 281         eltype *Delete(long key) { return Delete(key, key); }                  \
 282                                                                                \
 283     protected:                                                                 \
 284         void DoPut(long key, long value, eltype *data)                         \
 285         {                                                                      \
 286             size_t slot = (size_t)abs((int)(key % (long)m_hashSize));          \
 287                                                                                \
 288             if ( !m_hashTable[slot] )                                          \
 289             {                                                                  \
 290                 m_hashTable[slot] = new listclass(m_keyType);                  \
 291                 if ( m_deleteContents )                                        \
 292                     m_hashTable[slot]->DeleteContents(TRUE);                   \
 293             }                                                                  \
 294                                                                                \
 295             ((listclass *)m_hashTable[slot])->Append(value, data);             \
 296             m_count++;                                                         \
 297         }                                                                      \
 298     }
 299
 300 // this macro is to be used in the user code
 301 #define WX_DECLARE_HASH(el, list, hash) \
 302     _WX_DECLARE_HASH(el, list, hash, class)
 303
 304 // and this one does exactly the same thing but should be used inside the
 305 // library
 306 #define WX_DECLARE_EXPORTED_HASH(el, list, hash)  \
 307     _WX_DECLARE_HASH(el, list, hash, class WXDLLEXPORT)
 308
 309 #define WX_DECLARE_USER_EXPORTED_HASH(el, list, hash, usergoo)  \
 310     _WX_DECLARE_HASH(el, list, hash, class usergoo)
 311
 312 // delete all hash elements
 313 //
 314 // NB: the class declaration of the hash elements must be visible from the
 315 //     place where you use this macro, otherwise the proper destructor may not
 316 //     be called (a decent compiler should give a warning about it, but don't
 317 //     count on it)!
 318 #define WX_CLEAR_HASH_TABLE(array)                                           \
 319     {                                                                        \
 320         (array).BeginFind();                                                 \
 321         wxNode* it = (array).Next();                                         \
 322         while( it )                                                          \
 323         {                                                                    \
 324             delete it->GetData();                                            \
 325             it = (array).Next();                                             \
 326         }                                                                    \
 327         (array).Clear();                                                     \
 328     }
 329
 330 #endif
 331     // _WX_HASH_H__