eglib/src/gqueue.c

   1 /*
   2  * gqueue.c: Queue
   3  *
   4  * Author:
   5  *   Duncan Mak (duncan@novell.com)
   6  *   Gonzalo Paniagua Javier (gonzalo@novell.com)
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining
   9  * a copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sublicense, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be
  17  * included in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  20  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  22  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  23  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  24  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  25  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  * Copyright (c) 2006-2009 Novell, Inc.
  28  *
  29  */
  30
  31 #include <stdio.h>
  32 #include <glib.h>
  33
  34 gpointer
  35 g_queue_pop_head (GQueue *queue)
  36 {
  37         gpointer result;
  38         GList *old_head;
  39
  40         if (!queue || queue->length == 0)
  41                 return NULL;
  42
  43         result = queue->head->data;
  44         old_head = queue->head;
  45         queue->head = old_head->next;
  46         g_list_free_1 (old_head);
  47
  48         if (--queue->length)
  49                 queue->head->prev = NULL;
  50         else
  51                 queue->tail = NULL;
  52
  53         return result;
  54 }
  55
  56 gboolean
  57 g_queue_is_empty (GQueue *queue)
  58 {
  59         if (!queue)
  60                 return TRUE;
  61
  62         return queue->length == 0;
  63 }
  64
  65 void
  66 g_queue_push_head (GQueue *queue, gpointer head)
  67 {
  68         if (!queue)
  69                 return;
  70
  71         queue->head = g_list_prepend (queue->head, head);
  72
  73         if (!queue->tail)
  74                 queue->tail = queue->head;
  75
  76         queue->length ++;
  77 }
  78
  79 void
  80 g_queue_push_tail (GQueue *queue, gpointer data)
  81 {
  82         if (!queue)
  83                 return;
  84
  85         queue->tail = g_list_append (queue->tail, data);
  86         if (queue->head == NULL)
  87                 queue->head = queue->tail;
  88         else
  89                 queue->tail = queue->tail->next;
  90         queue->length++;
  91 }
  92
  93 GQueue *
  94 g_queue_new (void)
  95 {
  96         return g_new0 (GQueue, 1);
  97 }
  98
  99 void
 100 g_queue_free (GQueue *queue)
 101 {
 102         if (!queue)
 103                 return;
 104
 105         g_list_free (queue->head);
 106         g_free (queue);
 107 }