1/* 2 Unix SMB/CIFS implementation. 3 some simple double linked list macros 4 Copyright (C) Andrew Tridgell 1998 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program. If not, see <http://www.gnu.org/licenses/>. 18*/ 19 20/* To use these macros you must have a structure containing a next and 21 prev pointer */ 22 23#ifndef _DLINKLIST_H 24#define _DLINKLIST_H 25 26 27/* hook into the front of the list */ 28#define DLIST_ADD(list, p) \ 29do { \ 30 if (!(list)) { \ 31 (list) = (p); \ 32 (p)->next = (p)->prev = NULL; \ 33 } else { \ 34 (list)->prev = (p); \ 35 (p)->next = (list); \ 36 (p)->prev = NULL; \ 37 (list) = (p); \ 38 }\ 39} while (0) 40 41/* remove an element from a list - element doesn't have to be in list. */ 42#define DLIST_REMOVE(list, p) \ 43do { \ 44 if ((p) == (list)) { \ 45 (list) = (p)->next; \ 46 if (list) (list)->prev = NULL; \ 47 } else { \ 48 if ((p)->prev) (p)->prev->next = (p)->next; \ 49 if ((p)->next) (p)->next->prev = (p)->prev; \ 50 } \ 51 if ((p) && ((p) != (list))) (p)->next = (p)->prev = NULL; \ 52} while (0) 53 54/* promote an element to the top of the list */ 55#define DLIST_PROMOTE(list, p) \ 56do { \ 57 DLIST_REMOVE(list, p); \ 58 DLIST_ADD(list, p); \ 59} while (0) 60 61/* hook into the end of the list - needs the entry type */ 62#define DLIST_ADD_END(list, p, type) \ 63do { \ 64 if (!(list)) { \ 65 (list) = (p); \ 66 (p)->next = (p)->prev = NULL; \ 67 } else { \ 68 type tmp; \ 69 for (tmp = (list); tmp->next; tmp = tmp->next) ; \ 70 tmp->next = (p); \ 71 (p)->next = NULL; \ 72 (p)->prev = tmp; \ 73 } \ 74} while (0) 75 76/* insert 'p' after the given element 'el' in a list. If el is NULL then 77 this is the same as a DLIST_ADD() */ 78#define DLIST_ADD_AFTER(list, p, el) \ 79do { \ 80 if (!(list) || !(el)) { \ 81 DLIST_ADD(list, p); \ 82 } else { \ 83 p->prev = el; \ 84 p->next = el->next; \ 85 el->next = p; \ 86 if (p->next) p->next->prev = p; \ 87 }\ 88} while (0) 89 90/* demote an element to the end of the list, needs the entry type */ 91#define DLIST_DEMOTE(list, p, type) \ 92do { \ 93 DLIST_REMOVE(list, p); \ 94 DLIST_ADD_END(list, p, type); \ 95} while (0) 96 97/* concatenate two lists - putting all elements of the 2nd list at the 98 end of the first list */ 99#define DLIST_CONCATENATE(list1, list2, type) \ 100do { \ 101 if (!(list1)) { \ 102 (list1) = (list2); \ 103 } else { \ 104 type tmp; \ 105 for (tmp = (list1); tmp->next; tmp = tmp->next) ; \ 106 tmp->next = (list2); \ 107 if (list2) { \ 108 (list2)->prev = tmp; \ 109 } \ 110 } \ 111} while (0) 112 113#endif /* _DLINKLIST_H */ 114 115