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 // Copyright:   (c) Julian Smart
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_HASH_H__
  12 #define _WX_HASH_H__
  13
  14 #include "wx/defs.h"
  15 #include "wx/string.h"
  16
  17 #if !wxUSE_STD_CONTAINERS
  18     #include "wx/object.h"
  19 #else
  20     class WXDLLIMPEXP_FWD_BASE wxObject;
  21 #endif
  22
  23 // the default size of the hash
  24 #define wxHASH_SIZE_DEFAULT     (1000)
  25
  26 /*
  27  * A hash table is an array of user-definable size with lists
  28  * of data items hanging off the array positions.  Usually there'll
  29  * be a hit, so no search is required; otherwise we'll have to run down
  30  * the list to find the desired item.
  31 */
  32
  33 union wxHashKeyValue
  34 {
  35     long integer;
  36     wxString *string;
  37 };
  38
  39 // for some compilers (AIX xlC), defining it as friend inside the class is not
  40 // enough, so provide a real forward declaration
  41 class WXDLLIMPEXP_FWD_BASE wxHashTableBase;
  42
  43 class WXDLLIMPEXP_BASE wxHashTableBase_Node
  44 {
  45     friend class WXDLLIMPEXP_FWD_BASE wxHashTableBase;
  46     typedef class WXDLLIMPEXP_FWD_BASE wxHashTableBase_Node _Node;
  47 public:
  48     wxHashTableBase_Node( long key, void* value,
  49                           wxHashTableBase* table );
  50     wxHashTableBase_Node( const wxString&  key, void* value,
  51                           wxHashTableBase* table );
  52     ~wxHashTableBase_Node();
  53
  54     long GetKeyInteger() const { return m_key.integer; }
  55     const wxString& GetKeyString() const { return *m_key.string; }
  56
  57     void* GetData() const { return m_value; }
  58     void SetData( void* data ) { m_value = data; }
  59
  60 protected:
  61     _Node* GetNext() const { return m_next; }
  62
  63 protected:
  64     // next node in the chain
  65     wxHashTableBase_Node* m_next;
  66
  67     // key
  68     wxHashKeyValue m_key;
  69
  70     // value
  71     void* m_value;
  72
  73     // pointer to the hash containing the node, used to remove the
  74     // node from the hash when the user deletes the node iterating
  75     // through it
  76     // TODO: move it to wxHashTable_Node (only wxHashTable supports
  77     //       iteration)
  78     wxHashTableBase* m_hashPtr;
  79 };
  80
  81 class WXDLLIMPEXP_BASE wxHashTableBase
  82 #if !wxUSE_STD_CONTAINERS
  83     : public wxObject
  84 #endif
  85 {
  86     friend class WXDLLIMPEXP_FWD_BASE wxHashTableBase_Node;
  87 public:
  88     typedef wxHashTableBase_Node Node;
  89
  90     wxHashTableBase();
  91     virtual ~wxHashTableBase() { }
  92
  93     void Create( wxKeyType keyType = wxKEY_INTEGER,
  94                  size_t size = wxHASH_SIZE_DEFAULT );
  95     void Clear();
  96     void Destroy();
  97
  98     size_t GetSize() const { return m_size; }
  99     size_t GetCount() const { return m_count; }
 100
 101     void DeleteContents( bool flag ) { m_deleteContents = flag; }
 102
 103     static long MakeKey(const wxString& string);
 104
 105 protected:
 106     void DoPut( long key, long hash, void* data );
 107     void DoPut( const wxString&  key, long hash, void* data );
 108     void* DoGet( long key, long hash ) const;
 109     void* DoGet( const wxString&  key, long hash ) const;
 110     void* DoDelete( long key, long hash );
 111     void* DoDelete( const wxString&  key, long hash );
 112
 113 private:
 114     // Remove the node from the hash, *only called from
 115     // ~wxHashTable*_Node destructor
 116     void DoRemoveNode( wxHashTableBase_Node* node );
 117
 118     // destroys data contained in the node if appropriate:
 119     // deletes the key if it is a string and destrys
 120     // the value if m_deleteContents is true
 121     void DoDestroyNode( wxHashTableBase_Node* node );
 122
 123     // inserts a node in the table (at the end of the chain)
 124     void DoInsertNode( size_t bucket, wxHashTableBase_Node* node );
 125
 126     // removes a node from the table (fiven a pointer to the previous
 127     // but does not delete it (only deletes its contents)
 128     void DoUnlinkNode( size_t bucket, wxHashTableBase_Node* node,
 129                        wxHashTableBase_Node* prev );
 130
 131     // unconditionally deletes node value (invoking the
 132     // correct destructor)
 133     virtual void DoDeleteContents( wxHashTableBase_Node* node ) = 0;
 134
 135 protected:
 136     // number of buckets
 137     size_t m_size;
 138
 139     // number of nodes (key/value pairs)
 140     size_t m_count;
 141
 142     // table
 143     Node** m_table;
 144
 145     // key typ (INTEGER/STRING)
 146     wxKeyType m_keyType;
 147
 148     // delete contents when hash is cleared
 149     bool m_deleteContents;
 150
 151 private:
 152     wxDECLARE_NO_COPY_CLASS(wxHashTableBase);
 153 };
 154
 155 // ----------------------------------------------------------------------------
 156 // for compatibility only
 157 // ----------------------------------------------------------------------------
 158
 159 class WXDLLIMPEXP_BASE wxHashTable_Node : public wxHashTableBase_Node
 160 {
 161     friend class WXDLLIMPEXP_FWD_BASE wxHashTable;
 162 public:
 163     wxHashTable_Node( long key, void* value,
 164                       wxHashTableBase* table )
 165         : wxHashTableBase_Node( key, value, table ) { }
 166     wxHashTable_Node( const wxString&  key, void* value,
 167                       wxHashTableBase* table )
 168         : wxHashTableBase_Node( key, value, table ) { }
 169
 170     wxObject* GetData() const
 171         { return (wxObject*)wxHashTableBase_Node::GetData(); }
 172     void SetData( wxObject* data )
 173         { wxHashTableBase_Node::SetData( data ); }
 174
 175     wxHashTable_Node* GetNext() const
 176         { return (wxHashTable_Node*)wxHashTableBase_Node::GetNext(); }
 177 };
 178
 179 // should inherit protectedly, but it is public for compatibility in
 180 // order to publicly inherit from wxObject
 181 class WXDLLIMPEXP_BASE wxHashTable : public wxHashTableBase
 182 {
 183     typedef wxHashTableBase hash;
 184 public:
 185     typedef wxHashTable_Node Node;
 186     typedef wxHashTable_Node* compatibility_iterator;
 187 public:
 188     wxHashTable( wxKeyType keyType = wxKEY_INTEGER,
 189                  size_t size = wxHASH_SIZE_DEFAULT )
 190         : wxHashTableBase() { Create( keyType, size ); BeginFind(); }
 191     wxHashTable( const wxHashTable& table );
 192
 193     virtual ~wxHashTable() { Destroy(); }
 194
 195     const wxHashTable& operator=( const wxHashTable& );
 196
 197     // key and value are the same
 198     void Put(long value, wxObject *object)
 199         { DoPut( value, value, object ); }
 200     void Put(long lhash, long value, wxObject *object)
 201         { DoPut( value, lhash, object ); }
 202     void Put(const wxString& value, wxObject *object)
 203         { DoPut( value, MakeKey( value ), object ); }
 204     void Put(long lhash, const wxString& value, wxObject *object)
 205         { DoPut( value, lhash, object ); }
 206
 207     // key and value are the same
 208     wxObject *Get(long value) const
 209         { return (wxObject*)DoGet( value, value ); }
 210     wxObject *Get(long lhash, long value) const
 211         { return (wxObject*)DoGet( value, lhash ); }
 212     wxObject *Get(const wxString& value) const
 213         { return (wxObject*)DoGet( value, MakeKey( value ) ); }
 214     wxObject *Get(long lhash, const wxString& value) const
 215         { return (wxObject*)DoGet( value, lhash ); }
 216
 217     // Deletes entry and returns data if found
 218     wxObject *Delete(long key)
 219         { return (wxObject*)DoDelete( key, key ); }
 220     wxObject *Delete(long lhash, long key)
 221         { return (wxObject*)DoDelete( key, lhash ); }
 222     wxObject *Delete(const wxString& key)
 223         { return (wxObject*)DoDelete( key, MakeKey( key ) ); }
 224     wxObject *Delete(long lhash, const wxString& key)
 225         { return (wxObject*)DoDelete( key, lhash ); }
 226
 227     // Way of iterating through whole hash table (e.g. to delete everything)
 228     // Not necessary, of course, if you're only storing pointers to
 229     // objects maintained separately
 230     void BeginFind() { m_curr = NULL; m_currBucket = 0; }
 231     Node* Next();
 232
 233     void Clear() { wxHashTableBase::Clear(); }
 234
 235     size_t GetCount() const { return wxHashTableBase::GetCount(); }
 236 protected:
 237     // copy helper
 238     void DoCopy( const wxHashTable& copy );
 239
 240     // searches the next node starting from bucket bucketStart and sets
 241     // m_curr to it and m_currBucket to its bucket
 242     void GetNextNode( size_t bucketStart );
 243 private:
 244     virtual void DoDeleteContents( wxHashTableBase_Node* node );
 245
 246     // current node
 247     Node* m_curr;
 248
 249     // bucket the current node belongs to
 250     size_t m_currBucket;
 251 };
 252
 253 // defines a new type safe hash table which stores the elements of type eltype
 254 // in lists of class listclass
 255 #define _WX_DECLARE_HASH(eltype, dummy, hashclass, classexp)                  \
 256     classexp hashclass : public wxHashTableBase                               \
 257     {                                                                         \
 258     public:                                                                   \
 259         hashclass(wxKeyType keyType = wxKEY_INTEGER,                          \
 260                   size_t size = wxHASH_SIZE_DEFAULT)                          \
 261             : wxHashTableBase() { Create(keyType, size); }                    \
 262                                                                               \
 263         virtual ~hashclass() { Destroy(); }                                   \
 264                                                                               \
 265         void Put(long key, eltype *data) { DoPut(key, key, (void*)data); }    \
 266         void Put(long lhash, long key, eltype *data)                          \
 267             { DoPut(key, lhash, (void*)data); }                               \
 268         eltype *Get(long key) const { return (eltype*)DoGet(key, key); }      \
 269         eltype *Get(long lhash, long key) const                               \
 270             { return (eltype*)DoGet(key, lhash); }                            \
 271         eltype *Delete(long key) { return (eltype*)DoDelete(key, key); }      \
 272         eltype *Delete(long lhash, long key)                                  \
 273             { return (eltype*)DoDelete(key, lhash); }                         \
 274     private:                                                                  \
 275         virtual void DoDeleteContents( wxHashTableBase_Node* node )           \
 276             { delete (eltype*)node->GetData(); }                              \
 277                                                                               \
 278         DECLARE_NO_COPY_CLASS(hashclass)                                      \
 279     }
 280
 281
 282 // this macro is to be used in the user code
 283 #define WX_DECLARE_HASH(el, list, hash) \
 284     _WX_DECLARE_HASH(el, list, hash, class)
 285
 286 // and this one does exactly the same thing but should be used inside the
 287 // library
 288 #define WX_DECLARE_EXPORTED_HASH(el, list, hash)  \
 289     _WX_DECLARE_HASH(el, list, hash, class WXDLLIMPEXP_CORE)
 290
 291 #define WX_DECLARE_USER_EXPORTED_HASH(el, list, hash, usergoo)  \
 292     _WX_DECLARE_HASH(el, list, hash, class usergoo)
 293
 294 // delete all hash elements
 295 //
 296 // NB: the class declaration of the hash elements must be visible from the
 297 //     place where you use this macro, otherwise the proper destructor may not
 298 //     be called (a decent compiler should give a warning about it, but don't
 299 //     count on it)!
 300 #define WX_CLEAR_HASH_TABLE(hash)                                            \
 301     {                                                                        \
 302         (hash).BeginFind();                                                  \
 303         wxHashTable::compatibility_iterator it = (hash).Next();              \
 304         while( it )                                                          \
 305         {                                                                    \
 306             delete it->GetData();                                            \
 307             it = (hash).Next();                                              \
 308         }                                                                    \
 309         (hash).Clear();                                                      \
 310     }
 311
 312 #endif // _WX_HASH_H__