gobject/gobjectnotifyqueue.c

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General
  15  * Public License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19 #ifndef __G_NOTIFY_H__
  20 #define __G_NOTIFY_H__
  21
  22 #include        <string.h> /* memset */
  23 #include        <glib-object.h>
  24
  25 G_BEGIN_DECLS
  26
  27
  28 /* --- typedefs --- */
  29 typedef struct _GObjectNotifyContext          GObjectNotifyContext;
  30 typedef struct _GObjectNotifyQueue            GObjectNotifyQueue;
  31 typedef void (*GObjectNotifyQueueDispatcher) (GObject     *object,
  32                                               guint        n_pspecs,
  33                                               GParamSpec **pspecs);
  34
  35
  36 /* --- structures --- */
  37 struct _GObjectNotifyContext
  38 {
  39   GQuark                       quark_notify_queue;
  40   GObjectNotifyQueueDispatcher dispatcher;
  41   GTrashStack                 *_nqueue_trash; /* unused */
  42 };
  43 struct _GObjectNotifyQueue
  44 {
  45   GObjectNotifyContext *context;
  46   GSList               *pspecs;
  47   guint16               n_pspecs;
  48   guint16               freeze_count;
  49   /* currently, this structure abuses the GList allocation chain and thus
  50    * must be <= sizeof (GList)
  51    */
  52 };
  53
  54
  55 /* --- functions --- */
  56 static void
  57 g_object_notify_queue_free (gpointer data)
  58 {
  59   GObjectNotifyQueue *nqueue = data;
  60
  61   g_slist_free (nqueue->pspecs);
  62   g_list_free_1 ((void*) nqueue);
  63 }
  64
  65 static inline GObjectNotifyQueue*
  66 g_object_notify_queue_freeze (GObject              *object,
  67                               GObjectNotifyContext *context)
  68 {
  69   GObjectNotifyQueue *nqueue;
  70
  71   nqueue = g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);
  72   if (!nqueue)
  73     {
  74       nqueue = (void*) g_list_alloc ();
  75       memset (nqueue, 0, sizeof (*nqueue));
  76       nqueue->context = context;
  77       g_datalist_id_set_data_full (&object->qdata, context->quark_notify_queue,
  78                                    nqueue, g_object_notify_queue_free);
  79     }
  80
  81   g_return_val_if_fail (nqueue->freeze_count < 65535, nqueue);
  82   nqueue->freeze_count++;
  83
  84   return nqueue;
  85 }
  86
  87 static inline void
  88 g_object_notify_queue_thaw (GObject            *object,
  89                             GObjectNotifyQueue *nqueue)
  90 {
  91   GObjectNotifyContext *context = nqueue->context;
  92   GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
  93   GSList *slist;
  94   guint n_pspecs = 0;
  95
  96   g_return_if_fail (nqueue->freeze_count > 0);
  97
  98   nqueue->freeze_count--;
  99   if (nqueue->freeze_count)
 100     return;
 101   g_return_if_fail (object->ref_count > 0);
 102
 103   pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
 104   /* set first entry to NULL since it's checked unconditionally */
 105   pspecs[0] = NULL;
 106   for (slist = nqueue->pspecs; slist; slist = slist->next)
 107     {
 108       GParamSpec *pspec = slist->data;
 109       gint i = 0;
 110
 111       /* dedup, make pspecs in the list unique */
 112     redo_dedup_check:
 113       if (pspecs[i] == pspec)
 114         continue;
 115       if (++i < n_pspecs)
 116         goto redo_dedup_check;
 117
 118       pspecs[n_pspecs++] = pspec;
 119     }
 120   g_datalist_id_set_data (&object->qdata, context->quark_notify_queue, NULL);
 121
 122   if (n_pspecs)
 123     context->dispatcher (object, n_pspecs, pspecs);
 124   g_free (free_me);
 125 }
 126
 127 static inline void
 128 g_object_notify_queue_clear (GObject            *object,
 129                              GObjectNotifyQueue *nqueue)
 130 {
 131   g_return_if_fail (nqueue->freeze_count > 0);
 132
 133   g_slist_free (nqueue->pspecs);
 134   nqueue->pspecs = NULL;
 135   nqueue->n_pspecs = 0;
 136 }
 137
 138 static inline void
 139 g_object_notify_queue_add (GObject            *object,
 140                            GObjectNotifyQueue *nqueue,
 141                            GParamSpec         *pspec)
 142 {
 143   if (pspec->flags & G_PARAM_READABLE)
 144     {
 145       g_return_if_fail (nqueue->n_pspecs < 65535);
 146
 147       /* we do the deduping in _thaw */
 148       nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
 149       nqueue->n_pspecs++;
 150     }
 151 }
 152
 153 static inline GObjectNotifyQueue*
 154 g_object_notify_queue_from_object (GObject              *object,
 155                                    GObjectNotifyContext *context)
 156 {
 157   return g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);
 158 }
 159
 160
 161 G_END_DECLS
 162
 163 #endif /* __G_OBJECT_H__ */