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