code.delx.au - pulseaudio/blob - src/pulsecore/llist.h

   1 #ifndef foollistfoo
   2 #define foollistfoo
   3
   4 /* $Id$ */
   5
   6 /***
   7   This file is part of PulseAudio.
   8
   9   PulseAudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU Lesser General Public License as
  11   published by the Free Software Foundation; either version 2 of the
  12   License, or (at your option) any later version.
  13
  14   PulseAudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public
  20   License along with PulseAudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #include <assert.h>
  26
  27 /* Some macros for maintaining doubly linked lists */
  28
  29 /* The head of the linked list. Use this in the structure that shall
  30  * contain the head of the linked list */
  31 #define PA_LLIST_HEAD(t,name) t *name
  32
  33 /* The pointers in the linked list's items. Use this in the item structure */
  34 #define PA_LLIST_FIELDS(t) t *next, *prev
  35
  36 /* Initialize the list's head */
  37 #define PA_LLIST_HEAD_INIT(t,item) do { (item) = (t*) NULL; } while(0)
  38
  39 /* Initialize a list item */
  40 #define PA_LLIST_INIT(t,item) do { \
  41                                t *_item = (item); \
  42                                assert(_item); \
  43                                _item->prev = _item->next = NULL; \
  44                                } while(0)
  45
  46 /* Prepend an item to the list */
  47 #define PA_LLIST_PREPEND(t,head,item) do { \
  48                                         t **_head = &(head), *_item = (item); \
  49                                         assert(_item); \
  50                                         if ((_item->next = *_head)) \
  51                                            _item->next->prev = _item; \
  52                                         _item->prev = NULL; \
  53                                         *_head = _item; \
  54                                         } while (0)
  55
  56 /* Remove an item from the list */
  57 #define PA_LLIST_REMOVE(t,head,item) do { \
  58                                     t **_head = &(head), *_item = (item); \
  59                                     assert(_item); \
  60                                     if (_item->next) \
  61                                        _item->next->prev = _item->prev; \
  62                                     if (_item->prev) \
  63                                        _item->prev->next = _item->next; \
  64                                     else {\
  65                                        assert(*_head == _item); \
  66                                        *_head = _item->next; \
  67                                     } \
  68                                     _item->next = _item->prev = NULL; \
  69                                     } while(0)
  70
  71 #define PA_LLIST_FIND_HEAD(t,item,head) \
  72 do { \
  73     t **_head = (head), *_item = (item); \
  74     *_head = _item; \
  75     assert(_head); \
  76     while ((*_head)->prev) \
  77         *_head = (*_head)->prev; \
  78 } while (0)
  79
  80 #define PA_LLIST_INSERT_AFTER(t,head,a,b) \
  81 do { \
  82     t **_head = &(head), *_a = (a), *_b = (b); \
  83     assert(_b); \
  84     if (!_a) { \
  85         if ((_b->next = *_head)) \
  86             _b->next->prev = _b; \
  87         _b->prev = NULL; \
  88         *_head = _b; \
  89     } else { \
  90         if ((_b->next = _a->next)) \
  91             _b->next->prev = _b; \
  92         _b->prev = _a; \
  93         _a->next = _b; \
  94     } \
  95 } while (0)
  96
  97
  98 #endif