/* GObject - GLib Type, Object, Parameter and Signal Library

 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

/* WARNING:

 *

 *    This file is INSTALLED and other projects (outside of glib)

 *    #include its contents.

 */

#ifndef __G_OBJECT_NOTIFY_QUEUE_H__

#define __G_OBJECT_NOTIFY_QUEUE_H__

#include <string.h> /* memset */

#include <glib-object.h>

G_BEGIN_DECLS

/* --- typedefs --- */

typedef struct _GObjectNotifyContext          GObjectNotifyContext;

typedef struct _GObjectNotifyQueue            GObjectNotifyQueue;

typedef void (*GObjectNotifyQueueDispatcher) (GObject     *object,

					      guint        n_pspecs,

					      GParamSpec **pspecs);

/* --- structures --- */

struct _GObjectNotifyContext

{

  GQuark                       quark_notify_queue;

  GObjectNotifyQueueDispatcher dispatcher;

  GTrashStack                 *_nqueue_trash; /* unused */

};

struct _GObjectNotifyQueue

{

  GObjectNotifyContext *context;

  GSList               *pspecs;

  guint16               n_pspecs;

  guint16               freeze_count;

};

G_LOCK_DEFINE_STATIC(notify_lock);

/* --- functions --- */

static void

g_object_notify_queue_free (gpointer data)

{

  GObjectNotifyQueue *nqueue = data;

  g_slist_free (nqueue->pspecs);

  g_slice_free (GObjectNotifyQueue, nqueue);

}

static inline GObjectNotifyQueue*

g_object_notify_queue_freeze (GObject		   *object,

			      GObjectNotifyContext *context)

{

  GObjectNotifyQueue *nqueue;

  G_LOCK(notify_lock);

  nqueue = g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);

  if (!nqueue)

    {

      nqueue = g_slice_new0 (GObjectNotifyQueue);

      nqueue->context = context;

      g_datalist_id_set_data_full (&object->qdata, context->quark_notify_queue,

				   nqueue, g_object_notify_queue_free);

    }

  if (nqueue->freeze_count >= 65535)

    g_critical("Free queue for %s (%p) is larger than 65535,"

               " called g_object_freeze_notify() too often."

               " Forgot to call g_object_thaw_notify() or infinite loop",

               G_OBJECT_TYPE_NAME (object), object);

  else

    nqueue->freeze_count++;

  G_UNLOCK(notify_lock);

  return nqueue;

}

static inline void

g_object_notify_queue_thaw (GObject            *object,

			    GObjectNotifyQueue *nqueue)

{

  GObjectNotifyContext *context = nqueue->context;

  GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;

  GSList *slist;

  guint n_pspecs = 0;

  g_return_if_fail (nqueue->freeze_count > 0);

  g_return_if_fail (g_atomic_int_get(&object->ref_count) > 0);

  G_LOCK(notify_lock);

  /* Just make sure we never get into some nasty race condition */

  if (G_UNLIKELY(nqueue->freeze_count == 0)) {

    G_UNLOCK(notify_lock);

    g_warning ("%s: property-changed notification for %s(%p) is not frozen",

	       G_STRFUNC, G_OBJECT_TYPE_NAME (object), object);

    return;

  }

  nqueue->freeze_count--;

  if (nqueue->freeze_count) {

    G_UNLOCK(notify_lock);

    return;

  }

  pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;

  for (slist = nqueue->pspecs; slist; slist = slist->next)

    {

      pspecs[n_pspecs++] = slist->data;

    }

  g_datalist_id_set_data (&object->qdata, context->quark_notify_queue, NULL);

  G_UNLOCK(notify_lock);

  if (n_pspecs)

    context->dispatcher (object, n_pspecs, pspecs);

  g_free (free_me);

}

static inline void

g_object_notify_queue_clear (GObject            *object,

			     GObjectNotifyQueue *nqueue)

{

  g_return_if_fail (nqueue->freeze_count > 0);

  G_LOCK(notify_lock);

  g_slist_free (nqueue->pspecs);

  nqueue->pspecs = NULL;

  nqueue->n_pspecs = 0;

  G_UNLOCK(notify_lock);

}

static inline void

g_object_notify_queue_add (GObject            *object,

			   GObjectNotifyQueue *nqueue,

			   GParamSpec	      *pspec)

{

  if (pspec->flags & G_PARAM_READABLE)

    {

      GParamSpec *redirect;

      G_LOCK(notify_lock);

      g_return_if_fail (nqueue->n_pspecs < 65535);

      redirect = g_param_spec_get_redirect_target (pspec);

      if (redirect)

	pspec = redirect;

      /* we do the deduping in _thaw */

      if (g_slist_find (nqueue->pspecs, pspec) == NULL)

        {

          nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);

          nqueue->n_pspecs++;

        }

      G_UNLOCK(notify_lock);

    }

}

/* NB: This function is not threadsafe, do not ever use it if

 * you need a threadsafe notify queue.

 * Use g_object_notify_queue_freeze() to acquire the queue and

 * g_object_notify_queue_thaw() after you are done instead.

 */

static inline GObjectNotifyQueue*

g_object_notify_queue_from_object (GObject              *object,

                                   GObjectNotifyContext *context)

{

  return g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);

}

G_END_DECLS

#endif /* __G_OBJECT_NOTIFY_QUEUE_H__ */