ftobject.c

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Author : David Turner
Date : 2002-05-01 08:46:56
Hash : 10937304
Message : * include/freetype/internal/fthash.h, src/base/fthash.c: adding a generic implementation of dynamic hash tables using linear algorithm (to get rid of 'stalls' during resizes). This will be used in the future in at least three parts of the library: the cache sub-system, the object sub-system and the memory debugger. * include/freetype/internal/ftcore.h: added this header file to group all new definitions related to exception handling and memory management. It's very likely that this file will disappear or be renamed in the future.. * include/freetype/internal/ftobject.h, include/freetype/ftsysmem.h: adding comments to better explain the object sub-system as well as the new memory manager interface.

src/base/ftobject.c

#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 );

kc3-lang/freetype/src/base/ftobject.c

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kc3-lang/freetype /src/base/ftobject.c