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;
  42 };
  43 struct _GObjectNotifyQueue
  44 {
  45   GObjectNotifyContext *context;
  46   GSList               *pspecs;
  47   guint                 n_pspecs;
  48   guint                 freeze_count;
  49 };
  50
  51
  52 /* --- functions --- */
  53 static void
  54 g_object_notify_queue_free (gpointer data)
  55 {
  56   GObjectNotifyQueue *nqueue = data;
  57
  58   g_slist_free (nqueue->pspecs);
  59   g_trash_stack_push (&nqueue->context->nqueue_trash, nqueue);
  60 }
  61
  62 static inline GObjectNotifyQueue*
  63 g_object_notify_queue_freeze (GObject              *object,
  64                               GObjectNotifyContext *context)
  65 {
  66   GObjectNotifyQueue *nqueue;
  67
  68   nqueue = g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);
  69   if (!nqueue)
  70     {
  71       nqueue = g_trash_stack_pop (&context->nqueue_trash);
  72       if (!nqueue)
  73         {
  74           guint i;
  75
  76           nqueue = g_new (GObjectNotifyQueue, 16);
  77           for (i = 0; i < 15; i++)
  78             g_trash_stack_push (&context->nqueue_trash, nqueue++);
  79         }
  80       memset (nqueue, 0, sizeof (*nqueue));
  81       nqueue->context = context;
  82       g_datalist_id_set_data_full (&object->qdata, context->quark_notify_queue,
  83                                    nqueue, g_object_notify_queue_free);
  84     }
  85   nqueue->freeze_count++;
  86
  87   return nqueue;
  88 }
  89
  90 static inline void
  91 g_object_notify_queue_thaw (GObject            *object,
  92                             GObjectNotifyQueue *nqueue)
  93 {
  94   GObjectNotifyContext *context = nqueue->context;
  95   GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
  96   GSList *slist;
  97   guint n_pspecs = 0;
  98
  99   g_return_if_fail (nqueue->freeze_count > 0);
 100
 101   nqueue->freeze_count--;
 102   if (nqueue->freeze_count)
 103     return;
 104   g_return_if_fail (object->ref_count > 0);
 105
 106   pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
 107   /* set first entry to NULL since it's checked unconditionally */
 108   pspecs[0] = NULL;
 109   for (slist = nqueue->pspecs; slist; slist = slist->next)
 110     {
 111       GParamSpec *pspec = slist->data;
 112       gint i = 0;
 113
 114       /* dedup, make pspecs in the list unique */
 115     redo_dedup_check:
 116       if (pspecs[i] == pspec)
 117         continue;
 118       if (++i < n_pspecs)
 119         goto redo_dedup_check;
 120
 121       pspecs[n_pspecs++] = pspec;
 122     }
 123   g_datalist_id_set_data (&object->qdata, context->quark_notify_queue, NULL);
 124
 125   if (n_pspecs)
 126     context->dispatcher (object, n_pspecs, pspecs);
 127   g_free (free_me);
 128 }
 129
 130 static inline void
 131 g_object_notify_queue_clear (GObject            *object,
 132                              GObjectNotifyQueue *nqueue)
 133 {
 134   g_return_if_fail (nqueue->freeze_count > 0);
 135
 136   g_slist_free (nqueue->pspecs);
 137   nqueue->pspecs = NULL;
 138   nqueue->n_pspecs = 0;
 139 }
 140
 141 static inline void
 142 g_object_notify_queue_add (GObject            *object,
 143                            GObjectNotifyQueue *nqueue,
 144                            GParamSpec         *pspec)
 145 {
 146   if (pspec->flags & G_PARAM_READABLE)
 147     {
 148       /* we do the deduping in _thaw */
 149       nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
 150       nqueue->n_pspecs++;
 151     }
 152 }
 153
 154 static inline GObjectNotifyQueue*
 155 g_object_notify_queue_from_object (GObject              *object,
 156                                    GObjectNotifyContext *context)
 157 {
 158   return g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);
 159 }
 160
 161
 162 G_END_DECLS
 163
 164 #endif /* __G_OBJECT_H__ */