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0.99.22

    1: /* Generic linked list
    2:  * Copyright (C) 1997, 2000 Kunihiro Ishiguro
    3:  *
    4:  * This file is part of GNU Zebra.
    5:  *
    6:  * GNU Zebra is free software; you can redistribute it and/or modify it
    7:  * under the terms of the GNU General Public License as published by the
    8:  * Free Software Foundation; either version 2, or (at your option) any
    9:  * later version.
   10:  *
   11:  * GNU Zebra is distributed in the hope that it will be useful, but
   12:  * WITHOUT ANY WARRANTY; without even the implied warranty of
   13:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   14:  * General Public License for more details.
   15:  *
   16:  * You should have received a copy of the GNU General Public License
   17:  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
   18:  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   19:  * 02111-1307, USA.  
   20:  */
   21: 
   22: #ifndef _ZEBRA_LINKLIST_H
   23: #define _ZEBRA_LINKLIST_H
   24: 
   25: /* listnodes must always contain data to be valid. Adding an empty node
   26:  * to a list is invalid
   27:  */
   28: struct listnode 
   29: {
   30:   struct listnode *next;
   31:   struct listnode *prev;
   32:   
   33:   /* private member, use getdata() to retrieve, do not access directly */
   34:   void *data;
   35: };
   36: 
   37: struct list 
   38: {
   39:   struct listnode *head;
   40:   struct listnode *tail;
   41: 
   42:   /* invariant: count is the number of listnodes in the list */
   43:   unsigned int count;
   44: 
   45:   /*
   46:    * Returns -1 if val1 < val2, 0 if equal?, 1 if val1 > val2.
   47:    * Used as definition of sorted for listnode_add_sort
   48:    */
   49:   int (*cmp) (void *val1, void *val2);
   50: 
   51:   /* callback to free user-owned data when listnode is deleted. supplying
   52:    * this callback is very much encouraged!
   53:    */
   54:   void (*del) (void *val);
   55: };
   56: 
   57: #define listnextnode(X) ((X) ? ((X)->next) : NULL)
   58: #define listhead(X) ((X) ? ((X)->head) : NULL)
   59: #define listtail(X) ((X) ? ((X)->tail) : NULL)
   60: #define listcount(X) ((X)->count)
   61: #define list_isempty(X) ((X)->head == NULL && (X)->tail == NULL)
   62: #define listgetdata(X) (assert((X)->data != NULL), (X)->data)
   63: 
   64: /* Prototypes. */
   65: extern struct list *list_new(void); /* encouraged: set list.del callback on new lists */
   66: extern void list_free (struct list *);
   67: 
   68: extern void listnode_add (struct list *, void *);
   69: extern void listnode_add_sort (struct list *, void *);
   70: extern void listnode_add_after (struct list *, struct listnode *, void *);
   71: extern void listnode_delete (struct list *, void *);
   72: extern struct listnode *listnode_lookup (struct list *, void *);
   73: extern void *listnode_head (struct list *);
   74: 
   75: extern void list_delete (struct list *);
   76: extern void list_delete_all_node (struct list *);
   77: 
   78: /* For ospfd and ospf6d. */
   79: extern void list_delete_node (struct list *, struct listnode *);
   80: 
   81: /* For ospf_spf.c */
   82: extern void list_add_node_prev (struct list *, struct listnode *, void *);
   83: extern void list_add_node_next (struct list *, struct listnode *, void *);
   84: extern void list_add_list (struct list *, struct list *);
   85: 
   86: /* List iteration macro. 
   87:  * Usage: for (ALL_LIST_ELEMENTS (...) { ... }
   88:  * It is safe to delete the listnode using this macro.
   89:  */
   90: #define ALL_LIST_ELEMENTS(list,node,nextnode,data) \
   91:   (node) = listhead(list), ((data) = NULL); \
   92:   (node) != NULL && \
   93:     ((data) = listgetdata(node),(nextnode) = node->next, 1); \
   94:   (node) = (nextnode), ((data) = NULL)
   95: 
   96: /* read-only list iteration macro.
   97:  * Usage: as per ALL_LIST_ELEMENTS, but not safe to delete the listnode Only
   98:  * use this macro when it is *immediately obvious* the listnode is not
   99:  * deleted in the body of the loop. Does not have forward-reference overhead
  100:  * of previous macro.
  101:  */
  102: #define ALL_LIST_ELEMENTS_RO(list,node,data) \
  103:   (node) = listhead(list), ((data) = NULL);\
  104:   (node) != NULL && ((data) = listgetdata(node), 1); \
  105:   (node) = listnextnode(node), ((data) = NULL)
  106: 
  107: /* these *do not* cleanup list nodes and referenced data, as the functions
  108:  * do - these macros simply {de,at}tach a listnode from/to a list.
  109:  */
  110:  
  111: /* List node attach macro.  */
  112: #define LISTNODE_ATTACH(L,N) \
  113:   do { \
  114:     (N)->prev = (L)->tail; \
  115:     if ((L)->head == NULL) \
  116:       (L)->head = (N); \
  117:     else \
  118:       (L)->tail->next = (N); \
  119:     (L)->tail = (N); \
  120:     (L)->count++; \
  121:   } while (0)
  122: 
  123: /* List node detach macro.  */
  124: #define LISTNODE_DETACH(L,N) \
  125:   do { \
  126:     if ((N)->prev) \
  127:       (N)->prev->next = (N)->next; \
  128:     else \
  129:       (L)->head = (N)->next; \
  130:     if ((N)->next) \
  131:       (N)->next->prev = (N)->prev; \
  132:     else \
  133:       (L)->tail = (N)->prev; \
  134:     (L)->count--; \
  135:   } while (0)
  136: 
  137: /* Deprecated: 20050406 */
  138: #if !defined(QUAGGA_NO_DEPRECATED_INTERFACES)
  139: #warning "Using deprecated libzebra interfaces"
  140: #define LISTNODE_ADD(L,N) LISTNODE_ATTACH(L,N)
  141: #define LISTNODE_DELETE(L,N) LISTNODE_DETACH(L,N)
  142: #define nextnode(X) ((X) = (X)->next)
  143: #define getdata(X) listgetdata(X)
  144: #define LIST_LOOP(L,V,N) \
  145:   for (ALL_LIST_ELEMENTS_RO (L,N,V))
  146: #endif /* QUAGGA_NO_DEPRECATED_INTERFACES */
  147: 
  148: #endif /* _ZEBRA_LINKLIST_H */