src/misc-progs/list.h

   1 /* list.h by Jan Bobrowski. Inspired by list.h from Linux */
   2
   3 #ifndef LIST_H
   4 #define LIST_H
   5
   6 typedef struct list {
   7         struct list *next, *prev;
   8 } list_t;
   9
  10 static inline void list_link(struct list *a, struct list *b)
  11 {
  12         a->next = b;
  13         b->prev = a;
  14 }
  15
  16 static inline void list_add(struct list *head, struct list *item)
  17 {
  18         struct list *first = head->next;
  19         list_link(head, item);
  20         list_link(item, first);
  21 }
  22
  23 static inline void list_add_end(struct list *head, struct list *item)
  24 {
  25         struct list *last = head->prev;
  26         list_link(item, head);
  27         list_link(last, item);
  28 }
  29
  30 static inline list_t *list_del(struct list *item)
  31 {
  32         struct list *prev = item->prev, *next = item->next;
  33         list_link(prev, next);
  34         return next;
  35 }
  36
  37 static inline void list_init(struct list *head)
  38 {
  39         list_link(head, head);
  40 }
  41
  42 /* delete item from one list and add it to another */
  43 static inline void list_del_add(list_t *head, list_t *item)
  44 {
  45         list_t *prev = item->prev, *next = item->next;
  46         list_link(prev, next);
  47         next = head->next;
  48         list_link(head, item);
  49         list_link(item, next);
  50 }
  51
  52 /*static inline list_check(list_t *l)
  53 {
  54         list_t *a = l;
  55         list_t *b;
  56         do {
  57                 b = a->next;
  58                 assert(b->prev == a);
  59                 if(a==l) break;
  60                 a = b;
  61         } while(1);
  62 }*/
  63
  64 static inline void list_del_add_end(list_t *head, list_t *item)
  65 {
  66         list_t *prev = item->prev, *next = item->next;
  67         list_link(prev, next);
  68         prev = head->prev;
  69         list_link(item, head);
  70         item->prev = prev;
  71         prev->next = item;
  72 }
  73
  74 static inline void list_del_init(struct list *item)
  75 {
  76         struct list *prev = item->prev, *next = item->next;
  77         list_link(item, item);
  78         list_link(prev, next);
  79 }
  80
  81 static inline void list_join(struct list *a, struct list *b)
  82 {
  83         list_t *ae = a->prev;
  84         list_t *be = b->prev;
  85         b->prev = ae;
  86         a->prev = be;
  87         ae->next = b;
  88         be->next = a;
  89 }
  90
  91 static inline int list_empty(struct list *head)
  92 {
  93         return head->next == head;
  94 }
  95
  96 #define LIST(L) struct list L = {&L, &L}
  97
  98 #define list_entry(L, T, M) ((T*)((char*)(L) - (long)(&((T*)0)->M)))
  99 #define list_item(L, T, M) ((T*)((char*)(L) - (long)(&((T*)0)->M)))
 100
 101 #define list_first(H, T, M) list_item((H)->next, T, M)
 102 #define list_last(H, T, M) list_item((H)->prev, T, M)
 103 #define list_next(O, M) list_item((O)->M.next, typeof(*(O)), M)
 104
 105 /* remove first element and return it */
 106 static inline struct list *list_get(struct list *head)
 107 {
 108         struct list *item = head->next;
 109         struct list *next = item->next;
 110         list_link(head, next);
 111         return item;
 112 }
 113
 114 /* remove first element, initialize and return it */
 115 static inline struct list *list_get_init(struct list *head)
 116 {
 117         struct list *item = head->next;
 118         struct list *next = item->next;
 119         list_link(item, item);
 120         list_link(head, next);
 121         return item;
 122 }
 123
 124 #define list_get_entry(H, T, M) list_item(list_get((H)), T, M)
 125 #define list_get_init_entry(H, T, M) list_item(list_get_init((H)), T, M)
 126 #define list_get_item(H, T, M) list_item(list_get((H)), T, M)
 127 #define list_get_init_item(H, T, M) list_item(list_get_init((H)), T, M)
 128
 129 #endif