/*

 * Copyright © 2007  Chris Wilson

 * Copyright © 2009,2010  Red Hat, Inc.

 * Copyright © 2011,2012  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Contributor(s):

 *      Chris Wilson <chris@chris-wilson.co.uk>

 * Red Hat Author(s): Behdad Esfahbod

 * Google Author(s): Behdad Esfahbod

 */

#define HB_REFERENCE_COUNT_INERT_VALUE 0

#define HB_REFERENCE_COUNT_POISON_VALUE -0x0000DEAD

#define HB_REFERENCE_COUNT_INIT {HB_ATOMIC_INT_INIT (HB_REFERENCE_COUNT_INERT_VALUE)}

struct hb_reference_count_t

{

};

/* user_data */

struct hb_user_data_array_t

{

  struct hb_user_data_item_t {

    hb_user_data_key_t *key;

    void *data;

    hb_destroy_func_t destroy;

  };

  hb_mutex_t lock;

  hb_lockable_set_t<hb_user_data_item_t, hb_mutex_t> items;

  HB_INTERNAL bool set (hb_user_data_key_t *key,

                        void *              data,

                        hb_destroy_func_t   destroy,

                        hb_bool_t           replace);

  HB_INTERNAL void *get (hb_user_data_key_t *key);

};

struct hb_object_header_t

{

  hb_reference_count_t ref_count;

};

template <typename Type>

static inline void hb_object_trace (const Type *obj, const char *function)

{

  DEBUG_MSG (OBJECT, (void *) obj,

             "%s refcount=%d",

             function,

}

template <typename Type>

{

  Type *obj = (Type *) calloc (1, sizeof (Type));

  if (unlikely (!obj))

    return obj;

  hb_object_init (obj);

  hb_object_trace (obj, HB_FUNC);

  return obj;

}

template <typename Type>

static inline void hb_object_init (Type *obj)

{

}

template <typename Type>

static inline bool hb_object_is_inert (const Type *obj)

{

  return unlikely (obj->header.ref_count.is_inert ());

}

template <typename Type>

static inline bool hb_object_is_valid (const Type *obj)

{

  return likely (obj->header.ref_count.is_valid ());

}

template <typename Type>

static inline Type *hb_object_reference (Type *obj)

{

  hb_object_trace (obj, HB_FUNC);

  if (unlikely (!obj || hb_object_is_inert (obj)))

    return obj;

  assert (hb_object_is_valid (obj));

  obj->header.ref_count.inc ();

  return obj;

}

template <typename Type>

static inline bool hb_object_destroy (Type *obj)

{

  hb_object_trace (obj, HB_FUNC);

  if (unlikely (!obj || hb_object_is_inert (obj)))

    return false;

  assert (hb_object_is_valid (obj));

  if (obj->header.ref_count.dec () != 1)

    return false;

  hb_object_fini (obj);

  return true;

}

template <typename Type>

static inline void hb_object_fini (Type *obj)

{

  obj->header.ref_count.fini (); /* Do this before user_data */

  {

  }

}

template <typename Type>

static inline bool hb_object_set_user_data (Type               *obj,

                                            hb_user_data_key_t *key,

                                            void *              data,

                                            hb_destroy_func_t   destroy,

                                            hb_bool_t           replace)

{

  if (unlikely (!obj || hb_object_is_inert (obj)))

    return false;

  assert (hb_object_is_valid (obj));

retry:

  if (unlikely (!user_data))

  {

    user_data = (hb_user_data_array_t *) calloc (sizeof (hb_user_data_array_t), 1);

    if (unlikely (!user_data))

      return false;

    user_data->init ();

    {

      user_data->fini ();

      free (user_data);

      goto retry;

    }

  }

  return user_data->set (key, data, destroy, replace);

}

template <typename Type>

static inline void *hb_object_get_user_data (Type               *obj,

                                             hb_user_data_key_t *key)

{

    return nullptr;

  assert (hb_object_is_valid (obj));

}