#include "ftobject.c"#define  FT_MAGIC_DEATH   0xDEADdead#define  FT_MAGIC_CLASS   0x12345678#define  FT_OBJECT_CHECK(o)                                  \           ( FT_OBJECT(o)              != NULL            && \             FT_OBJECT(o)->clazz       != NULL            && \             FT_OBJECT(o)->ref_count   >= 1               && \             FT_OBJECT(o)->clazz->magic == FT_MAGIC_CLASS ) /*******************************************************************/ /*******************************************************************/ /*****                                                         *****/ /*****                                                         *****/ /*****                  M E T A - C L A S S                    *****/ /*****                                                         *****/ /*****                                                         *****/ /*******************************************************************/ /*******************************************************************/ /* we use a dynamic hash table to map types to classes */ /* this structure defines the layout of each node of   */ /* this table                                          */  typedef struct FT_ClassHNodeRec_  {    FT_HashNodeRec  hnode;    FT_Type         ctype;    FT_Class        clazz;  } FT_ClassHNodeRec, *FT_ClassHNode; /* the meta class contains a type -> class mapping */ /* and owns all class objects..                    */ /*                                                 */  typedef struct FT_MetaClassRec_  {    FT_ClassRec  clazz;    FT_HashRec   type_to_class;  } FT_MetaClassRec, *FT_MetaClass; /* forward declaration */  static const FT_TypeRec  ft_meta_class_type; /* destroy a given class */  static void  ft_class_hnode_destroy( FT_ClassHNode  node )  {    FT_Clazz   clazz  = node->clazz;    FT_Memory  memory = clazz->memory;    FT_Type    ctype  = clazz->type;    if ( ctype->class_done )      ctype->class_done( clazz );    FT_FREE( clazz );    node->clazz = NULL;    node->type  = NULL;    FT_FREE( node );  }  static FT_Int  ft_class_hnode_compare( const FT_ClassHNode  node1,                          const FT_ClassHNode  node2 )  {    return ( node1->type == node2->type );  }  static void  ft_metaclass_done( FT_MetaClass  meta )  {    /* clear all objects */    ft_hash_done( &meta->type_to_class,                  (FT_Hash_ForeachFunc) ft_class_destroy,                   NULL );    meta->clazz->object.clazz    = NULL;    meta->clazz->object.ref_count = 0;    meta->clazz->magic            = FT_MAGIC_DEATH;  }  static void  ft_metaclass_init( FT_MetaClass  meta,                     FT_Library    library )  {    FT_ClassRec*  clazz = meta->clazz;    /* the meta-class is its OWN class !! */    clazz->object.clazz     = (FT_Class) clazz;    clazz->object.ref_count = 1;    clazz->magic            = FT_MAGIC_CLASS;    clazz->library          = library;    clazz->memory           = library->memory;    clazz->type             = &ft_metaclass_type;    clazz->info             = NULL;    clazz->obj_size         = sizeof( FT_ClassRec );    clazz->obj_init         = NULL;    clazz->obj_done         = NULL;    ft_hash_init( &meta->type_to_class,                  (FT_Hash_CompareFunc) ft_class_hnode_compare,                  library->memory );  } /* find or create the class corresponding to a given type */  static FT_Class  ft_metaclass_get_class( FT_MetaClass  meta,                          FT_Type       ctype )  {    FT_ClassHNodeRec   keynode, *node, **pnode;    FT_Memory          memory;    keynode.hnode.hash = (FT_UInt32)( ctype >> 2 );    keynode.type       = type;    pnode = (FT_ClassHNode) ft_hash_lookup( &meta->type_to_class,                                            &noderec );    node  = *pnode;    if ( node != NULL )      return node->clazz;    memory = FT_CLASS__MEMORY(meta);    node   = FT_MEM_SAFE_ALLOC( sizeof(*node) );    if ( node != NULL )    {      FT_ClassRec*  clazz;      clazz = FT_MEM_SAFE_ALLOC( ctype->class_size );      if ( clazz == NULL )      {        FT_FREE( node );        FT_XTHROW( FT_Err_Out_Of_Memory );      }    }  }  static const FT_TypeRec  ft_meta_class_type =  {    "FT2.MetaClass",    NULL,    sizeof( FT_MetaClassRec ),    (FT_Object_InitFunc)  ft_metaclass_init,    (FT_Object_DoneFunc)  ft_metaclass_done,    sizeof( FT_ClassRec ),    (FT_Object_InitFunc)  ft_class_init,    (FT_Object_DoneFunc)  ft_class_done  };  FT_BASE_DEF( FT_Int )  ft_object_check( FT_Pointer  obj )  {    return FT_OBJECT_CHECK(obj);  }  FT_BASE_DEF( FT_Int )  ft_object_is_a( FT_Pointer  obj,                  FT_Class    clazz )  {    if ( FT_OBJECT_CHECK(obj) )    {      FT_Object  o = FT_OBJECT(obj);      FT_Class   c = FT_OBJECT__CLASS(obj);      do      {        if ( c == clazz )          return 1;        c = c->super;      }      while ( c == NULL );      return (clazz == NULL);    }  } /* the cleanup routine for all objects */  static void  ft_object_cleanup( FT_Object  object )  {    FT_Memory  memory = FT_OBJECT__MEMORY(object);    FT_Class   clazz  = FT_OBJECT__CLASS(object);    if ( clazz->obj_done )      clazz->obj_done( object );    FT_FREE( object );  }  FT_BASE_DEF( FT_Object )  ft_object_new( FT_Class    clazz,                 FT_Pointer  init_data )  {    FT_Memory  memory;    FT_Object  obj;    FT_ASSERT_IS_CLASS(clazz);    memory         = FT_CLASS__MEMORY(clazz);    obj            = ft_mem_alloc( clazz->obj_size, memory );    obj->clazz     = clazz;    obj->ref_count = 1;    if ( clazz->obj_init )    {      FT_CleanupStack  stack = FT_MEMORY__CLEANUP(memory);      ft_cleanup_push( stack, obj, (FT_CleanupFunc) ft_object_cleanup, NULL );      clazz->obj_init( obj, init_data );      ft_cleanup_pop( stack, obj, 0 );    }    return obj;  }  FT_BASE_DEF( void )  ft_object_create( FT_Object  *pobject,                    FT_Class    clazz,                    FT_Pointer  init_data )  {    FT_Memory  memory;    FT_Object  obj;    FT_ASSERT_IS_CLASS(clazz);    memory         = FT_CLASS__MEMORY(memory);    obj            = ft_mem_alloc( clazz->obj_size, memory );    obj->clazz     = clazz;    obj->ref_count = 1;    *pobject       = obj;    if ( clazz->obj_init )      clazz->obj_init( obj, init_data );  }  FT_BASE_DEF( FT_Class )  ft_class_find_by_type( FT_Type    type,                         FT_Memory  memory )  {  }  FT_BASE_DEF( FT_Class )  ft_class_find_by_name( FT_CString  class_name,                         FT_Memory   memory );  FT_BASE_DEF( FT_Object )  ft_object_new_from_type( FT_Type     type,                           FT_Pointer  data,                           FT_Memory   memory );  FT_BASE_DEF( void )  ft_object_create_from_type( FT_Object  *pobject,                              FT_Type     type,                              FT_Pointer  init_data,                              FT_Memory   memory );  FT_BASE_DEF( void )  ft_object_push( FT_Object  object );  FT_BASE_DEF( void )  ft_object_pop( FT_Object  object );  FT_BASE_DEF( void )  ft_object_pop_destroy( FT_Object  object );