ref: 8b61525b9ac44d4ca37524b7e3b588e9f3c9870d
dir: /src/base/ftobject.c/
#include <ft2build.h>
#include FT_INTERNAL_OBJECT_H
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_OBJECTS_H
#define FT_MAGIC_DEATH 0xDEADdead
#define FT_MAGIC_CLASS 0x12345678
#define FT_TYPE_HASH(x) (( (FT_UInt32)(x) >> 2 )^( (FT_UInt32)(x) >> 10 ))
#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 )
#define FT_CLASS_CHECK(c) \
( FT_CLASS(c) != NULL && FT_CLASS(c)->magic == FT_MAGIC_CLASS )
#define FT_ASSERT_IS_CLASS(c) FT_ASSERT( FT_CLASS_CHECK(c) )
/*******************************************************************/
/*******************************************************************/
/***** *****/
/***** *****/
/***** M E T A - C L A S S *****/
/***** *****/
/***** *****/
/*******************************************************************/
/*******************************************************************/
/* forward declaration */
FT_BASE_DEF( FT_Error )
ft_metaclass_init( FT_MetaClass meta,
FT_Library library );
/* forward declaration */
FT_BASE_DEF( void )
ft_metaclass_done( FT_MetaClass meta );
/* class type for the meta-class itself */
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) NULL,
(FT_Object_DoneFunc) NULL
};
/* destroy a given class */
static void
ft_class_hnode_destroy( FT_ClassHNode node )
{
FT_Class clazz = node->clazz;
FT_Memory memory = clazz->memory;
if ( clazz->class_done )
clazz->class_done( (FT_Object) clazz );
FT_FREE( clazz );
node->clazz = NULL;
node->type = NULL;
FT_FREE( node );
}
static FT_Int
ft_type_equal( FT_Type type1,
FT_Type type2 )
{
if ( type1 == type2 )
goto Ok;
if ( type1 == NULL || type2 == NULL )
goto Fail;
/* compare parent types */
if ( type1->super != type2->super )
{
if ( type1->super == NULL ||
type2->super == NULL ||
!ft_type_equal( type1, type2 ) )
goto Fail;
}
/* compare type names */
if ( type1->name != type2->name )
{
if ( type1->name == NULL ||
type2->name == NULL ||
ft_strcmp( type1->name, type2->name ) != 0 )
goto Fail;
}
/* compare the other type fields */
if ( type1->class_size != type2->class_size ||
type1->class_init != type2->class_init ||
type1->class_done != type2->class_done ||
type1->obj_size != type2->obj_size ||
type1->obj_init != type2->obj_init ||
type1->obj_done != type2->obj_done )
goto Fail;
Ok:
return 1;
Fail:
return 0;
}
static FT_Int
ft_class_hnode_equal( const FT_ClassHNode node1,
const FT_ClassHNode node2 )
{
FT_Type type1 = node1->type;
FT_Type type2 = node2->type;
/* comparing the pointers should work in 99% of cases */
return ( type1 == type2 ) ? 1 : ft_type_equal( type1, type2 );
}
FT_BASE_DEF( void )
ft_metaclass_done( FT_MetaClass meta )
{
/* clear all classes */
ft_hash_done( &meta->type_to_class,
(FT_Hash_ForeachFunc) ft_class_hnode_destroy,
NULL );
meta->clazz.object.clazz = NULL;
meta->clazz.object.ref_count = 0;
meta->clazz.magic = FT_MAGIC_DEATH;
}
FT_BASE_DEF( FT_Error )
ft_metaclass_init( FT_MetaClass meta,
FT_Library library )
{
FT_ClassRec* clazz = (FT_ClassRec*) &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_meta_class_type;
clazz->info = NULL;
clazz->class_done = (FT_Object_DoneFunc) ft_metaclass_done;
clazz->obj_size = sizeof( FT_ClassRec );
clazz->obj_init = NULL;
clazz->obj_done = NULL;
return ft_hash_init( &meta->type_to_class,
(FT_Hash_EqualFunc) ft_class_hnode_equal,
library->memory );
}
/* find or create the class corresponding to a given type */
/* note that this function will retunr NULL in case of */
/* memory overflow */
/* */
static FT_Class
ft_metaclass_get_class( FT_MetaClass meta,
FT_Type ctype )
{
FT_ClassHNodeRec keynode, *node, **pnode;
FT_Memory memory;
FT_ClassRec* clazz;
FT_Class parent;
FT_Error error;
keynode.hnode.hash = FT_TYPE_HASH( ctype );
keynode.type = ctype;
pnode = (FT_ClassHNode*) ft_hash_lookup( &meta->type_to_class,
(FT_HashNode) &keynode );
node = *pnode;
if ( node != NULL )
{
clazz = (FT_ClassRec*) node->clazz;
goto Exit;
}
memory = FT_CLASS__MEMORY(meta);
clazz = NULL;
parent = NULL;
if ( ctype->super != NULL )
{
FT_ASSERT( ctype->super->class_size <= ctype->class_size );
FT_ASSERT( ctype->super->obj_size <= ctype->obj_size );
parent = ft_metaclass_get_class( meta, ctype->super );
}
if ( !FT_NEW( node ) )
{
if ( !FT_ALLOC( clazz, ctype->class_size ) )
{
if ( parent )
FT_MEM_COPY( (FT_ClassRec*)clazz, parent, parent->type->class_size );
clazz->object.clazz = (FT_Class) meta;
clazz->object.ref_count = 1;
clazz->memory = memory;
clazz->library = FT_CLASS__LIBRARY(meta);
clazz->super = parent;
clazz->type = ctype;
clazz->info = NULL;
clazz->magic = FT_MAGIC_CLASS;
clazz->class_done = ctype->class_done;
clazz->obj_size = ctype->obj_size;
clazz->obj_init = ctype->obj_init;
clazz->obj_done = ctype->obj_done;
if ( parent )
{
if ( clazz->class_done == NULL )
clazz->class_done = parent->class_done;
if ( clazz->obj_init == NULL )
clazz->obj_init = parent->obj_init;
if ( clazz->obj_done == NULL )
clazz->obj_done = parent->obj_done;
}
/* find class initializer, if any */
{
FT_Type ztype = ctype;
FT_Object_InitFunc cinit = NULL;
do
{
cinit = ztype->class_init;
if ( cinit != NULL )
break;
ztype = ztype->super;
}
while ( ztype != NULL );
/* then call it when needed */
if ( cinit != NULL )
error = cinit( (FT_Object) clazz, NULL );
}
}
if (error)
{
if ( clazz )
{
/* we always call the class destructor when */
/* an error was detected in the constructor !! */
if ( clazz->class_done )
clazz->class_done( (FT_Object) clazz );
FT_FREE( clazz );
}
FT_FREE( node );
}
}
Exit:
return (FT_Class) clazz;
}
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_Class c = FT_OBJECT__CLASS(obj);
do
{
if ( c == clazz )
return 1;
c = c->super;
}
while ( c == NULL );
return (clazz == NULL);
}
return 0;
}
FT_BASE_DEF( FT_Error )
ft_object_create( FT_Object *pobject,
FT_Class clazz,
FT_Pointer init_data )
{
FT_Memory memory;
FT_Error error;
FT_Object obj;
FT_ASSERT_IS_CLASS(clazz);
memory = FT_CLASS__MEMORY(clazz);
if ( !FT_ALLOC( obj, clazz->obj_size ) )
{
obj->clazz = clazz;
obj->ref_count = 1;
if ( clazz->obj_init )
{
error = clazz->obj_init( obj, init_data );
if ( error )
{
/* IMPORTANT: call the destructor when an error */
/* was detected in the constructor !! */
if ( clazz->obj_done )
clazz->obj_done( obj );
FT_FREE( obj );
}
}
}
*pobject = obj;
return error;
}
FT_BASE_DEF( FT_Class )
ft_class_find_by_type( FT_Type type,
FT_Library library )
{
FT_MetaClass meta = &library->meta_class;
return ft_metaclass_get_class( meta, type );
}
FT_BASE_DEF( FT_Error )
ft_object_create_from_type( FT_Object *pobject,
FT_Type type,
FT_Pointer init_data,
FT_Library library )
{
FT_Class clazz;
FT_Error error;
clazz = ft_class_find_by_type( type, library );
if ( clazz )
error = ft_object_create( pobject, clazz, init_data );
else
{
*pobject = NULL;
error = FT_Err_Out_Of_Memory;
}
return error;
}