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
  20 #ifndef __G_OBJECT_NOTIFY_QUEUE_H__
  21 #define __G_OBJECT_NOTIFY_QUEUE_H__
  22
  23 #include <string.h> /* memset */
  24
  25 #include <glib-object.h>
  26
  27 G_BEGIN_DECLS
  28
  29
  30 /* --- typedefs --- */
  31 typedef struct _GObjectNotifyContext          GObjectNotifyContext;
  32 typedef struct _GObjectNotifyQueue            GObjectNotifyQueue;
  33 typedef void (*GObjectNotifyQueueDispatcher) (GObject     *object,
  34                                               guint        n_pspecs,
  35                                               GParamSpec **pspecs);
  36
  37
  38 /* --- structures --- */
  39 struct _GObjectNotifyContext
  40 {
  41   GQuark                       quark_notify_queue;
  42   GObjectNotifyQueueDispatcher dispatcher;
  43   GTrashStack                 *_nqueue_trash; /* unused */
  44 };
  45 struct _GObjectNotifyQueue
  46 {
  47   GObjectNotifyContext *context;
  48   GSList               *pspecs;
  49   guint16               n_pspecs;
  50   guint16               freeze_count;
  51   /* currently, this structure abuses the GList allocation chain and thus
  52    * must be <= sizeof (GList)
  53    */
  54 };
  55
  56
  57 /* --- functions --- */
  58 static void
  59 g_object_notify_queue_free (gpointer data)
  60 {
  61   GObjectNotifyQueue *nqueue = data;
  62
  63   g_slist_free (nqueue->pspecs);
  64   g_list_free_1 ((void*) nqueue);
  65 }
  66
  67 static inline GObjectNotifyQueue*
  68 g_object_notify_queue_freeze (GObject              *object,
  69                               GObjectNotifyContext *context)
  70 {
  71   GObjectNotifyQueue *nqueue;
  72
  73   nqueue = g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);
  74   if (!nqueue)
  75     {
  76       nqueue = (void*) g_list_alloc ();
  77       memset (nqueue, 0, sizeof (*nqueue));
  78       nqueue->context = context;
  79       g_datalist_id_set_data_full (&object->qdata, context->quark_notify_queue,
  80                                    nqueue, g_object_notify_queue_free);
  81     }
  82
  83   g_return_val_if_fail (nqueue->freeze_count < 65535, nqueue);
  84   nqueue->freeze_count++;
  85
  86   return nqueue;
  87 }
  88
  89 static inline void
  90 g_object_notify_queue_thaw (GObject            *object,
  91                             GObjectNotifyQueue *nqueue)
  92 {
  93   GObjectNotifyContext *context = nqueue->context;
  94   GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
  95   GSList *slist;
  96   guint n_pspecs = 0;
  97
  98   g_return_if_fail (nqueue->freeze_count > 0);
  99
 100   nqueue->freeze_count--;
 101   if (nqueue->freeze_count)
 102     return;
 103   g_return_if_fail (object->ref_count > 0);
 104
 105   pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
 106   /* set first entry to NULL since it's checked unconditionally */
 107   pspecs[0] = NULL;
 108   for (slist = nqueue->pspecs; slist; slist = slist->next)
 109     {
 110       GParamSpec *pspec = slist->data;
 111       guint i = 0;
 112
 113       /* dedup, make pspecs in the list unique */
 114     redo_dedup_check:
 115       if (pspecs[i] == pspec)
 116         continue;
 117       if (++i < n_pspecs)
 118         goto redo_dedup_check;
 119
 120       pspecs[n_pspecs++] = pspec;
 121     }
 122   g_datalist_id_set_data (&object->qdata, context->quark_notify_queue, NULL);
 123
 124   if (n_pspecs)
 125     context->dispatcher (object, n_pspecs, pspecs);
 126   g_free (free_me);
 127 }
 128
 129 static inline void
 130 g_object_notify_queue_clear (GObject            *object,
 131                              GObjectNotifyQueue *nqueue)
 132 {
 133   g_return_if_fail (nqueue->freeze_count > 0);
 134
 135   g_slist_free (nqueue->pspecs);
 136   nqueue->pspecs = NULL;
 137   nqueue->n_pspecs = 0;
 138 }
 139
 140 static inline void
 141 g_object_notify_queue_add (GObject            *object,
 142                            GObjectNotifyQueue *nqueue,
 143                            GParamSpec         *pspec)
 144 {
 145   if (pspec->flags & G_PARAM_READABLE)
 146     {
 147       GParamSpec *redirect;
 148
 149       g_return_if_fail (nqueue->n_pspecs < 65535);
 150
 151       redirect = g_param_spec_get_redirect_target (pspec);
 152       if (redirect)
 153         pspec = redirect;
 154
 155       /* we do the deduping in _thaw */
 156       nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
 157       nqueue->n_pspecs++;
 158     }
 159 }
 160
 161 static inline GObjectNotifyQueue*
 162 g_object_notify_queue_from_object (GObject              *object,
 163                                    GObjectNotifyContext *context)
 164 {
 165   return g_datalist_id_get_data (&object->qdata, context->quark_notify_queue);
 166 }
 167
 168
 169 G_END_DECLS
 170
 171 #endif /* __G_OBJECT_NOTIFY_QUEUE_H__ */