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   Copyright 2004-2006 Lennart Poettering
  10
  11   PulseAudio is free software; you can redistribute it and/or modify
  12   it under the terms of the GNU Lesser General Public License as
  13   published by the Free Software Foundation; either version 2 of the
  14   License, or (at your option) any later version.
  15
  16   PulseAudio is distributed in the hope that it will be useful, but
  17   WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   General Public License for more details.
  20
  21   You should have received a copy of the GNU Lesser General Public
  22   License along with PulseAudio; if not, write to the Free Software
  23   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  24   USA.
  25 ***/
  26
  27 #include <assert.h>
  28
  29 /* Some macros for maintaining doubly linked lists */
  30
  31 /* The head of the linked list. Use this in the structure that shall
  32  * contain the head of the linked list */
  33 #define PA_LLIST_HEAD(t,name) t *name
  34
  35 /* The pointers in the linked list's items. Use this in the item structure */
  36 #define PA_LLIST_FIELDS(t) t *next, *prev
  37
  38 /* Initialize the list's head */
  39 #define PA_LLIST_HEAD_INIT(t,item) do { (item) = (t*) NULL; } while(0)
  40
  41 /* Initialize a list item */
  42 #define PA_LLIST_INIT(t,item) do { \
  43                                t *_item = (item); \
  44                                assert(_item); \
  45                                _item->prev = _item->next = NULL; \
  46                                } while(0)
  47
  48 /* Prepend an item to the list */
  49 #define PA_LLIST_PREPEND(t,head,item) do { \
  50                                         t **_head = &(head), *_item = (item); \
  51                                         assert(_item); \
  52                                         if ((_item->next = *_head)) \
  53                                            _item->next->prev = _item; \
  54                                         _item->prev = NULL; \
  55                                         *_head = _item; \
  56                                         } while (0)
  57
  58 /* Remove an item from the list */
  59 #define PA_LLIST_REMOVE(t,head,item) do { \
  60                                     t **_head = &(head), *_item = (item); \
  61                                     assert(_item); \
  62                                     if (_item->next) \
  63                                        _item->next->prev = _item->prev; \
  64                                     if (_item->prev) \
  65                                        _item->prev->next = _item->next; \
  66                                     else {\
  67                                        assert(*_head == _item); \
  68                                        *_head = _item->next; \
  69                                     } \
  70                                     _item->next = _item->prev = NULL; \
  71                                     } while(0)
  72
  73 #define PA_LLIST_FIND_HEAD(t,item,head) \
  74 do { \
  75     t **_head = (head), *_item = (item); \
  76     *_head = _item; \
  77     assert(_head); \
  78     while ((*_head)->prev) \
  79         *_head = (*_head)->prev; \
  80 } while (0)
  81
  82 #define PA_LLIST_INSERT_AFTER(t,head,a,b) \
  83 do { \
  84     t **_head = &(head), *_a = (a), *_b = (b); \
  85     assert(_b); \
  86     if (!_a) { \
  87         if ((_b->next = *_head)) \
  88             _b->next->prev = _b; \
  89         _b->prev = NULL; \
  90         *_head = _b; \
  91     } else { \
  92         if ((_b->next = _a->next)) \
  93             _b->next->prev = _b; \
  94         _b->prev = _a; \
  95         _a->next = _b; \
  96     } \
  97 } while (0)
  98
  99
 100 #endif