contrib/include/wx/fl/garbagec.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        garbagec.h
   3 // Purpose:     GarbageCollector class.
   4 // Author:      Aleksandras Gluchovas (@Lithuania)
   5 // Modified by:
   6 // Created:     ??/10/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Aleksandras Gluchovas
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef __GARBAGEC_G__
  13 #define __GARBAGEC_G__
  14
  15 #ifdef __GNUG__
  16     #pragma interface "garbagec.h"
  17 #endif
  18
  19 #include "wx/list.h"
  20
  21 struct GCItem
  22 {
  23     void*      mpObj;
  24     wxList    mRefs;   // references to other nodes
  25 };
  26
  27 inline void* gc_node_to_obj( wxNode* pGCNode )
  28 {
  29     return ( (GCItem*) (pGCNode->Data()) )->mpObj;
  30 }
  31
  32 /*
  33 This class implements an extremely slow but simple garbage collection algorithm.
  34 */
  35
  36 class GarbageCollector
  37 {
  38 protected:
  39     wxList mAllNodes;
  40     wxList mRegularLst;
  41     wxList mCycledLst;
  42
  43         // Internal method for finding a node.
  44     wxNode* FindItemNode( void* pForObj );
  45
  46         // Internal method for resolving references.
  47     void    ResolveReferences();
  48
  49         // Internal method for findind and freeing a node.
  50     wxNode* FindReferenceFreeItemNode();
  51
  52         // Remove references to this node.
  53     void    RemoveReferencesToNode( wxNode* pItemNode );
  54
  55         // Destroys a list of items.
  56     void    DestroyItemList( wxList& lst );
  57
  58 public:
  59
  60         // Default constructor.
  61     GarbageCollector() {}
  62
  63         // Destructor.
  64     virtual ~GarbageCollector();
  65
  66         // Prepare data for garbage collection.
  67
  68     virtual void AddObject( void* pObj, int refCnt = 1 );
  69
  70         // Prepare data for garbage collection.
  71
  72     virtual void AddDependency( void* pObj, void* pDependsOnObj );
  73
  74         // Executes garbage collection algorithm.
  75
  76     virtual void ArrangeCollection();
  77
  78         // Accesses the results of the algorithm.
  79
  80     wxList& GetRegularObjects();
  81
  82         // Get cycled objects.
  83
  84     wxList& GetCycledObjects();
  85
  86         // Removes all data from the garbage collector.
  87
  88     void Reset();
  89 };
  90
  91 #endif /* __GARBAGEC_G__ */
  92