libopkg/active_list.c

   1 /* active_list.h - the opkg package management system
   2
   3    Tick Chen <tick@openmoko.com>
   4
   5    Copyright (C) 2008 Openmoko Inc.
   6
   7    This program is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU General Public License as
   9    published by the Free Software Foundation; either version 2, or (at
  10    your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    General Public License for more details.
  16 */
  17
  18
  19 #include "active_list.h"
  20 #include <stdio.h>
  21
  22
  23 void active_list_init(struct active_list *ptr) {
  24     INIT_LIST_HEAD(&ptr->node);
  25     INIT_LIST_HEAD(&ptr->depend);
  26     ptr->depended = NULL;
  27 }
  28
  29 /**
  30  */
  31 struct active_list * active_list_next(struct active_list *head, struct active_list *ptr) {
  32     struct active_list *next=NULL;
  33     if (!head) {
  34         fprintf(stderr, "active_list_prev head = %p, ptr = %p invalid value!!\n", head, ptr);
  35         return NULL;
  36     }
  37     if (!ptr)
  38         ptr = head;
  39     next = list_entry(ptr->node.next, struct active_list, node);
  40     if (next == head ) {
  41         return NULL;
  42     }
  43     if (ptr->depended && &ptr->depended->depend == ptr->node.next ) {
  44         return ptr->depended;
  45     }
  46     while (next->depend.next != &next->depend) {
  47         next = list_entry(next->depend.next, struct active_list, node);
  48     }
  49     return next;
  50 }
  51
  52
  53 void active_list_clear(struct active_list *head) {
  54 }
  55
  56 void active_list_add_depend(struct active_list *node, struct active_list *depend) {
  57     list_del_init(&depend->node);
  58     list_add_tail(&depend->node, &node->depend);
  59     depend->depended  = node;
  60 }
  61
  62 void active_list_add(struct active_list *head, struct active_list *node) {
  63     list_del_init(&node->node);
  64     list_add_tail(&node->node, &head->node);
  65     node->depended  = head;
  66 }