gts/fifo.c

   1 /* GTS - Library for the manipulation of triangulated surfaces
   2  * Copyright (C) 1999 Stéphane Popinet
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library 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  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * 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 #include "gts.h"
  21
  22 struct _GtsFifo {
  23   GList * head;
  24   GList * tail;
  25 };
  26
  27 /**
  28  * gts_fifo_new:
  29  *
  30  * Returns: a new #GtsFifo.
  31  */
  32 GtsFifo * gts_fifo_new ()
  33 {
  34   GtsFifo * fifo = g_malloc (sizeof (GtsFifo));
  35
  36   fifo->head = fifo->tail = NULL;
  37   return fifo;
  38 }
  39
  40 /**
  41  * gts_fifo_write:
  42  * @fifo: a #GtsFifo.
  43  * @fp: a file pointer.
  44  *
  45  * Writes the content of @fifo in @fp.
  46  */
  47 void gts_fifo_write (GtsFifo * fifo, FILE * fp)
  48 {
  49   GList * i;
  50
  51   g_return_if_fail (fifo != NULL);
  52   g_return_if_fail (fp != NULL);
  53
  54   fprintf (fp, "[");
  55   i = fifo->head;
  56   while (i) {
  57     fprintf (fp, "%p ", i->data);
  58     i = i->next;
  59   }
  60   fprintf (fp, "]");
  61 }
  62
  63 /**
  64  * gts_fifo_push:
  65  * @fifo: a #GtsFifo.
  66  * @data: data to add to @fifo.
  67  *
  68  * Push @data into @fifo.
  69  */
  70 void gts_fifo_push (GtsFifo * fifo, gpointer data)
  71 {
  72   g_return_if_fail (fifo != NULL);
  73
  74   fifo->head = g_list_prepend (fifo->head, data);
  75   if (fifo->tail == NULL)
  76     fifo->tail = fifo->head;
  77 }
  78
  79 /**
  80  * gts_fifo_pop:
  81  * @fifo: a #GtsFifo.
  82  *
  83  * Removes the first element from @fifo.
  84  *
  85  * Returns: the first element in @fifo or %NULL if @fifo is empty.
  86  */
  87 gpointer gts_fifo_pop (GtsFifo * fifo)
  88 {
  89   gpointer data;
  90   GList * tail;
  91
  92   g_return_val_if_fail (fifo != NULL, NULL);
  93
  94   if (fifo->tail == NULL)
  95     return NULL;
  96   tail = fifo->tail->prev;
  97   data = fifo->tail->data;
  98   fifo->head = g_list_remove_link (fifo->head, fifo->tail);
  99   g_list_free_1 (fifo->tail);
 100   fifo->tail = tail;
 101   return data;
 102 }
 103
 104 /**
 105  * gts_fifo_top:
 106  * @fifo: a #GtsFifo.
 107  *
 108  * Returns: the first element in @fifo or %NULL if @fifo is empty.
 109  */
 110 gpointer gts_fifo_top (GtsFifo * fifo)
 111 {
 112   g_return_val_if_fail (fifo != NULL, NULL);
 113
 114   if (fifo->tail == NULL)
 115     return NULL;
 116   return fifo->tail->data;
 117 }
 118
 119 /**
 120  * gts_fifo_size:
 121  * @fifo: a #GtsFifo.
 122  *
 123  * Returns: the number of elements in @fifo.
 124  */
 125 guint gts_fifo_size (GtsFifo * fifo)
 126 {
 127   g_return_val_if_fail (fifo != NULL, 0);
 128
 129   return g_list_length (fifo->head);
 130 }
 131
 132 /**
 133  * gts_fifo_destroy:
 134  * @fifo: a #GtsFifo.
 135  *
 136  * Frees all the memory allocated for @fifo.
 137  */
 138 void gts_fifo_destroy (GtsFifo * fifo)
 139 {
 140   g_return_if_fail (fifo != NULL);
 141   g_list_free (fifo->head);
 142   g_free (fifo);
 143 }
 144
 145 /**
 146  * gts_fifo_is_empty:
 147  * @fifo: a #GtsFifo.
 148  *
 149  * Returns: %TRUE if @fifo is empty, %FALSE otherwise.
 150  */
 151 gboolean gts_fifo_is_empty (GtsFifo * fifo)
 152 {
 153   g_return_val_if_fail (fifo != NULL, TRUE);
 154
 155   return (fifo->head == NULL);
 156 }
 157
 158 /**
 159  * gts_fifo_foreach:
 160  * @fifo: a #GtsFifo.
 161  * @func: a #GtsFunc.
 162  * @data: user data to be passed to @func.
 163  *
 164  * Calls @func in order for each item in @fifo, passing @data.
 165  */
 166 void gts_fifo_foreach (GtsFifo * fifo, GtsFunc func, gpointer data)
 167 {
 168   GList * i;
 169
 170   g_return_if_fail (fifo != NULL);
 171   g_return_if_fail (func != NULL);
 172
 173   i = fifo->tail;
 174   while (i) {
 175     (* func) (i->data, data);
 176     i = i->prev;
 177   }
 178 }
 179
 180 /**
 181  * gts_fifo_reverse:
 182  * @fifo: a #GtsFifo.
 183  *
 184  * Reverses the order of elements in @fifo.
 185  */
 186 void gts_fifo_reverse (GtsFifo * fifo)
 187 {
 188   g_return_if_fail (fifo != NULL);
 189
 190   fifo->tail = fifo->head;
 191   fifo->head = g_list_reverse (fifo->head);
 192 }