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 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     // remove the item, returning TRUE if the item was found and deleted
 131     bool Delete(long key) const;
 132
 133     // clean up
 134     void Destroy();
 135
 136 private:
 137     wxArrayLong **m_keys;
 138     wxArrayString **m_values;
 139
 140     // the size of array above
 141     size_t m_hashSize;
 142
 143     DECLARE_NO_COPY_CLASS(wxStringHashTable)
 144 };
 145
 146 // ----------------------------------------------------------------------------
 147 // for compatibility only
 148 // ----------------------------------------------------------------------------
 149
 150 class WXDLLEXPORT wxHashTable : public wxObject
 151 {
 152 public:
 153     int n;
 154     int current_position;
 155     wxNode *current_node;
 156
 157     unsigned int key_type;
 158     wxList **hash_table;
 159
 160     wxHashTable(int the_key_type = wxKEY_INTEGER,
 161                 int size = wxHASH_SIZE_DEFAULT);
 162     ~wxHashTable();
 163
 164     // copy ctor and assignment operator
 165     wxHashTable(const wxHashTable& table) : wxObject()
 166         { DoCopy(table); }
 167     wxHashTable& operator=(const wxHashTable& table)
 168         { Clear(); DoCopy(table); return *this; }
 169
 170     void DoCopy(const wxHashTable& table);
 171
 172     void Destroy();
 173
 174     bool Create(int the_key_type = wxKEY_INTEGER,
 175                 int size = wxHASH_SIZE_DEFAULT);
 176
 177     // Note that there are 2 forms of Put, Get.
 178     // With a key and a value, the *value* will be checked
 179     // when a collision is detected. Otherwise, if there are
 180     // 2 items with a different value but the same key,
 181     // we'll retrieve the WRONG ONE. So where possible,
 182     // supply the required value along with the key.
 183     // In fact, the value-only versions make a key, and still store
 184     // the value. The use of an explicit key might be required
 185     // e.g. when combining several values into one key.
 186     // When doing that, it's highly likely we'll get a collision,
 187     // e.g. 1 + 2 = 3, 2 + 1 = 3.
 188
 189     // key and value are NOT necessarily the same
 190     void Put(long key, long value, wxObject *object);
 191     void Put(long key, const wxChar *value, wxObject *object);
 192
 193     // key and value are the same
 194     void Put(long value, wxObject *object);
 195     void Put(const wxChar *value, wxObject *object);
 196
 197     // key and value not the same
 198     wxObject *Get(long key, long value) const;
 199     wxObject *Get(long key, const wxChar *value) const;
 200
 201     // key and value are the same
 202     wxObject *Get(long value) const;
 203     wxObject *Get(const wxChar *value) const;
 204
 205     // Deletes entry and returns data if found
 206     wxObject *Delete(long key);
 207     wxObject *Delete(const wxChar *key);
 208
 209     wxObject *Delete(long key, int value);
 210     wxObject *Delete(long key, const wxChar *value);
 211
 212     // Construct your own integer key from a string, e.g. in case
 213     // you need to combine it with something
 214     long MakeKey(const wxChar *string) const;
 215
 216     // Way of iterating through whole hash table (e.g. to delete everything)
 217     // Not necessary, of course, if you're only storing pointers to
 218     // objects maintained separately
 219
 220     void BeginFind();
 221     wxNode *Next();
 222
 223     void DeleteContents(bool flag);
 224     void Clear();
 225
 226     // Returns number of nodes
 227     size_t GetCount() const { return m_count; }
 228
 229 private:
 230     size_t m_count;             // number of elements in the hashtable
 231     bool m_deleteContents;
 232
 233     DECLARE_DYNAMIC_CLASS(wxHashTable)
 234 };
 235
 236 // defines a new type safe hash table which stores the elements of type eltype
 237 // in lists of class listclass
 238 #define _WX_DECLARE_HASH(eltype, listclass, hashclass, classexp)               \
 239     classexp hashclass : public wxHashTableBase                                \
 240     {                                                                          \
 241     public:                                                                    \
 242         hashclass(wxKeyType keyType = wxKEY_INTEGER,                           \
 243                   size_t size = wxHASH_SIZE_DEFAULT)                           \
 244             { Create(keyType, size); }                                         \
 245                                                                                \
 246         ~hashclass() { Destroy(); }                                            \
 247                                                                                \
 248         void Put(long key, long val, eltype *data) { DoPut(key, val, data); }  \
 249         void Put(long key, eltype *data) { DoPut(key, key, data); }            \
 250                                                                                \
 251         eltype *Get(long key, long value) const                                \
 252         {                                                                      \
 253             wxNodeBase *node = GetNode(key, value);                            \
 254             return node ? ((listclass::Node *)node)->GetData() : (eltype *)0;  \
 255         }                                                                      \
 256         eltype *Get(long key) const { return Get(key, key); }                  \
 257                                                                                \
 258         eltype *Delete(long key, long value)                                   \
 259         {                                                                      \
 260             eltype *data;                                                      \
 261                                                                                \
 262             wxNodeBase *node = GetNode(key, value);                            \
 263             if ( node )                                                        \
 264             {                                                                  \
 265                 data = ((listclass::Node *)node)->GetData();                   \
 266                                                                                \
 267                 delete node;                                                   \
 268                 m_count--;                                                     \
 269             }                                                                  \
 270             else                                                               \
 271             {                                                                  \
 272                 data = (eltype *)0;                                            \
 273             }                                                                  \
 274                                                                                \
 275             return data;                                                       \
 276         }                                                                      \
 277         eltype *Delete(long key) { return Delete(key, key); }                  \
 278                                                                                \
 279     protected:                                                                 \
 280         void DoPut(long key, long value, eltype *data)                         \
 281         {                                                                      \
 282             size_t slot = (size_t)abs((int)(key % (long)m_hashSize));          \
 283                                                                                \
 284             if ( !m_hashTable[slot] )                                          \
 285             {                                                                  \
 286                 m_hashTable[slot] = new listclass(m_keyType);                  \
 287                 if ( m_deleteContents )                                        \
 288                     m_hashTable[slot]->DeleteContents(TRUE);                   \
 289             }                                                                  \
 290                                                                                \
 291             ((listclass *)m_hashTable[slot])->Append(value, data);             \
 292             m_count++;                                                         \
 293         }                                                                      \
 294     }
 295
 296 // this macro is to be used in the user code
 297 #define WX_DECLARE_HASH(el, list, hash) \
 298     _WX_DECLARE_HASH(el, list, hash, class)
 299
 300 // and this one does exactly the same thing but should be used inside the
 301 // library
 302 #define WX_DECLARE_EXPORTED_HASH(el, list, hash)  \
 303     _WX_DECLARE_HASH(el, list, hash, class WXDLLEXPORT)
 304
 305 #define WX_DECLARE_USER_EXPORTED_HASH(el, list, hash, usergoo)  \
 306     _WX_DECLARE_HASH(el, list, hash, class usergoo)
 307
 308 #endif
 309     // _WX_HASH_H__