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 #ifdef __GNUG__
  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 WXDLLEXPORT 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 // ----------------------------------------------------------------------------
  76 // a hash table which stores longs
  77 // ----------------------------------------------------------------------------
  78
  79 class WXDLLEXPORT wxHashTableLong : public wxObject
  80 {
  81 public:
  82     wxHashTableLong(size_t size = wxHASH_SIZE_DEFAULT)
  83         { Init(size); }
  84     virtual ~wxHashTableLong();
  85
  86     void Create(size_t size = wxHASH_SIZE_DEFAULT);
  87     void Destroy();
  88
  89     size_t GetSize() const { return m_hashSize; }
  90     size_t GetCount() const { return m_count; }
  91
  92     void Put(long key, long value);
  93     long Get(long key) const;
  94     long Delete(long key);
  95
  96 protected:
  97     void Init(size_t size);
  98
  99 private:
 100     wxArrayLong **m_values,
 101                 **m_keys;
 102
 103     // the size of array above
 104     size_t m_hashSize;
 105
 106     // the total number of elements in the hash
 107     size_t m_count;
 108
 109     // not implemented yet
 110     DECLARE_NO_COPY_CLASS(wxHashTableLong)
 111 };
 112
 113 // ----------------------------------------------------------------------------
 114 // wxStringHashTable: a hash table which indexes strings with longs
 115 // ----------------------------------------------------------------------------
 116
 117 class WXDLLEXPORT wxStringHashTable : public wxObject
 118 {
 119 public:
 120     wxStringHashTable(size_t sizeTable = wxHASH_SIZE_DEFAULT);
 121     virtual ~wxStringHashTable();
 122
 123     // add a string associated with this key to the table
 124     void Put(long key, const wxString& value);
 125
 126     // get the string from the key: if not found, an empty string is returned
 127     // and the wasFound is set to FALSE if not NULL
 128     wxString Get(long key, bool *wasFound = NULL) const;
 129
 130     // clean up
 131     void Destroy();
 132
 133 private:
 134     wxArrayLong **m_keys;
 135     wxArrayString **m_values;
 136
 137     // the size of array above
 138     size_t m_hashSize;
 139
 140     DECLARE_NO_COPY_CLASS(wxStringHashTable)
 141 };
 142
 143 // ----------------------------------------------------------------------------
 144 // for compatibility only
 145 // ----------------------------------------------------------------------------
 146
 147 class WXDLLEXPORT wxHashTable : public wxObject
 148 {
 149 public:
 150     int n;
 151     int current_position;
 152     wxNode *current_node;
 153
 154     unsigned int key_type;
 155     wxList **hash_table;
 156
 157     wxHashTable(int the_key_type = wxKEY_INTEGER,
 158                 int size = wxHASH_SIZE_DEFAULT);
 159     ~wxHashTable();
 160
 161     // copy ctor and assignment operator
 162     wxHashTable(const wxHashTable& table) : wxObject()
 163         { DoCopy(table); }
 164     wxHashTable& operator=(const wxHashTable& table)
 165         { Clear(); DoCopy(table); return *this; }
 166
 167     void DoCopy(const wxHashTable& table);
 168
 169     void Destroy();
 170
 171     bool Create(int the_key_type = wxKEY_INTEGER,
 172                 int size = wxHASH_SIZE_DEFAULT);
 173
 174     // Note that there are 2 forms of Put, Get.
 175     // With a key and a value, the *value* will be checked
 176     // when a collision is detected. Otherwise, if there are
 177     // 2 items with a different value but the same key,
 178     // we'll retrieve the WRONG ONE. So where possible,
 179     // supply the required value along with the key.
 180     // In fact, the value-only versions make a key, and still store
 181     // the value. The use of an explicit key might be required
 182     // e.g. when combining several values into one key.
 183     // When doing that, it's highly likely we'll get a collision,
 184     // e.g. 1 + 2 = 3, 2 + 1 = 3.
 185
 186     // key and value are NOT necessarily the same
 187     void Put(long key, long value, wxObject *object);
 188     void Put(long key, const wxChar *value, wxObject *object);
 189
 190     // key and value are the same
 191     void Put(long value, wxObject *object);
 192     void Put(const wxChar *value, wxObject *object);
 193
 194     // key and value not the same
 195     wxObject *Get(long key, long value) const;
 196     wxObject *Get(long key, const wxChar *value) const;
 197
 198     // key and value are the same
 199     wxObject *Get(long value) const;
 200     wxObject *Get(const wxChar *value) const;
 201
 202     // Deletes entry and returns data if found
 203     wxObject *Delete(long key);
 204     wxObject *Delete(const wxChar *key);
 205
 206     wxObject *Delete(long key, int value);
 207     wxObject *Delete(long key, const wxChar *value);
 208
 209     // Construct your own integer key from a string, e.g. in case
 210     // you need to combine it with something
 211     long MakeKey(const wxChar *string) const;
 212
 213     // Way of iterating through whole hash table (e.g. to delete everything)
 214     // Not necessary, of course, if you're only storing pointers to
 215     // objects maintained separately
 216
 217     void BeginFind();
 218     wxNode *Next();
 219
 220     void DeleteContents(bool flag);
 221     void Clear();
 222
 223     // Returns number of nodes
 224     size_t GetCount() const { return m_count; }
 225
 226 private:
 227     size_t m_count;             // number of elements in the hashtable
 228     bool m_deleteContents;
 229
 230     DECLARE_DYNAMIC_CLASS(wxHashTable)
 231 };
 232
 233 // defines a new type safe hash table which stores the elements of type eltype
 234 // in lists of class listclass
 235 #define _WX_DECLARE_HASH(eltype, listclass, hashclass, classexp)               \
 236     classexp hashclass : public wxHashTableBase                                \
 237     {                                                                          \
 238     public:                                                                    \
 239         hashclass(wxKeyType keyType = wxKEY_INTEGER,                           \
 240                   size_t size = wxHASH_SIZE_DEFAULT)                           \
 241             { Create(keyType, size); }                                         \
 242                                                                                \
 243         ~hashclass() { Destroy(); }                                            \
 244                                                                                \
 245         void Put(long key, long val, eltype *data) { DoPut(key, val, data); }  \
 246         void Put(long key, eltype *data) { DoPut(key, key, data); }            \
 247                                                                                \
 248         eltype *Get(long key, long value) const                                \
 249         {                                                                      \
 250             wxNodeBase *node = GetNode(key, value);                            \
 251             return node ? ((listclass::Node *)node)->GetData() : (eltype *)0;  \
 252         }                                                                      \
 253         eltype *Get(long key) const { return Get(key, key); }                  \
 254                                                                                \
 255         eltype *Delete(long key, long value)                                   \
 256         {                                                                      \
 257             eltype *data;                                                      \
 258                                                                                \
 259             wxNodeBase *node = GetNode(key, value);                            \
 260             if ( node )                                                        \
 261             {                                                                  \
 262                 data = ((listclass::Node *)node)->GetData();                   \
 263                                                                                \
 264                 delete node;                                                   \
 265                 m_count--;                                                     \
 266             }                                                                  \
 267             else                                                               \
 268             {                                                                  \
 269                 data = (eltype *)0;                                            \
 270             }                                                                  \
 271                                                                                \
 272             return data;                                                       \
 273         }                                                                      \
 274         eltype *Delete(long key) { return Delete(key, key); }                  \
 275                                                                                \
 276     protected:                                                                 \
 277         void DoPut(long key, long value, eltype *data)                         \
 278         {                                                                      \
 279             size_t slot = (size_t)abs((int)(key % (long)m_hashSize));          \
 280                                                                                \
 281             if ( !m_hashTable[slot] )                                          \
 282             {                                                                  \
 283                 m_hashTable[slot] = new listclass(m_keyType);                  \
 284                 if ( m_deleteContents )                                        \
 285                     m_hashTable[slot]->DeleteContents(TRUE);                   \
 286             }                                                                  \
 287                                                                                \
 288             ((listclass *)m_hashTable[slot])->Append(value, data);             \
 289             m_count++;                                                         \
 290         }                                                                      \
 291     }
 292
 293 // this macro is to be used in the user code
 294 #define WX_DECLARE_HASH(el, list, hash) \
 295     _WX_DECLARE_HASH(el, list, hash, class)
 296
 297 // and this one does exactly the same thing but should be used inside the
 298 // library
 299 #define WX_DECLARE_EXPORTED_HASH(el, list, hash)  \
 300     _WX_DECLARE_HASH(el, list, hash, class WXDLLEXPORT)
 301
 302 #define WX_DECLARE_USER_EXPORTED_HASH(el, list, hash, usergoo)  \
 303     _WX_DECLARE_HASH(el, list, hash, class usergoo)
 304
 305 #endif
 306     // _WX_HASH_H__