libopkg/void_list.c

   1 /* void_list.c - the opkg package management system
   2
   3    Carl D. Worth
   4
   5    Copyright (C) 2001 University of Southern California
   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 #include "void_list.h"
  19 #include "libbb/libbb.h"
  20
  21 void void_list_elt_init(void_list_elt_t *elt, void *data)
  22 {
  23     INIT_LIST_HEAD(&elt->node);
  24     elt->data = data;
  25 }
  26
  27 static void_list_elt_t * void_list_elt_new (void *data) {
  28     void_list_elt_t *elt;
  29     /* freed in void_list_elt_deinit */
  30     elt = xcalloc(1, sizeof(void_list_elt_t));
  31     void_list_elt_init(elt, data);
  32     return elt;
  33 }
  34
  35 void void_list_elt_deinit(void_list_elt_t *elt)
  36 {
  37     list_del_init(&elt->node);
  38     void_list_elt_init(elt, NULL);
  39     free(elt);
  40 }
  41
  42 void void_list_init(void_list_t *list)
  43 {
  44     INIT_LIST_HEAD(&list->head);
  45 }
  46
  47 void void_list_deinit(void_list_t *list)
  48 {
  49     void_list_elt_t *elt;
  50
  51     while (!void_list_empty(list)) {
  52         elt = void_list_pop(list);
  53         void_list_elt_deinit(elt);
  54     }
  55     INIT_LIST_HEAD(&list->head);
  56 }
  57
  58 void void_list_append(void_list_t *list, void *data)
  59 {
  60     void_list_elt_t *elt = void_list_elt_new(data);
  61     list_add_tail(&elt->node, &list->head);
  62 }
  63
  64 void void_list_push(void_list_t *list, void *data)
  65 {
  66     void_list_elt_t *elt = void_list_elt_new(data);
  67     list_add(&elt->node, &list->head);
  68 }
  69
  70 void_list_elt_t *void_list_pop(void_list_t *list)
  71 {
  72     struct list_head *node;
  73
  74     if (void_list_empty(list))
  75         return NULL;
  76     node = list->head.next;
  77     list_del_init(node);
  78     return list_entry(node, void_list_elt_t, node);
  79 }
  80
  81 void *void_list_remove(void_list_t *list, void_list_elt_t **iter)
  82 {
  83     void_list_elt_t *pos, *n;
  84     void_list_elt_t *old_elt;
  85     void *old_data = NULL;
  86
  87     old_elt = *iter;
  88     if (!old_elt)
  89         return old_data;
  90     old_data = old_elt->data;
  91
  92     list_for_each_entry_safe(pos, n, &list->head, node) {
  93         if (pos == old_elt)
  94             break;
  95     }
  96     if ( pos != old_elt) {
  97         opkg_msg(ERROR, "Internal error: element not found in list.\n");
  98         return NULL;
  99     }
 100
 101     *iter = list_entry(pos->node.prev, void_list_elt_t, node);
 102     void_list_elt_deinit(pos);
 103
 104     return old_data;
 105 }
 106
 107 /* remove element containing elt data, using cmp(elt->data, target_data) == 0. */
 108 void *void_list_remove_elt(void_list_t *list, const void *target_data, void_list_cmp_t cmp)
 109 {
 110     void_list_elt_t *pos, *n;
 111     void *old_data = NULL;
 112     list_for_each_entry_safe(pos, n, &list->head, node) {
 113         if ( pos->data && cmp(pos->data, target_data)==0 ){
 114             old_data = pos->data;
 115             void_list_elt_deinit(pos);
 116             break;
 117         }
 118     }
 119     return old_data;
 120 }
 121
 122 void_list_elt_t *void_list_first(void_list_t *list) {
 123     struct list_head *elt;
 124     if (!list)
 125         return NULL;
 126     elt = list->head.next;
 127     if (elt == &list->head ) {
 128         return NULL;
 129     }
 130     return list_entry(elt, void_list_elt_t, node);
 131 }
 132
 133 void_list_elt_t *void_list_prev(void_list_t *list, void_list_elt_t *node) {
 134     struct list_head *elt;
 135     if (!list || !node)
 136         return NULL;
 137     elt = node->node.prev;
 138     if (elt == &list->head ) {
 139         return NULL;
 140     }
 141     return list_entry(elt, void_list_elt_t, node);
 142 }
 143
 144 void_list_elt_t *void_list_next(void_list_t *list, void_list_elt_t *node) {
 145     struct list_head *elt;
 146     if (!list || !node)
 147         return NULL;
 148     elt = node->node.next;
 149     if (elt == &list->head ) {
 150         return NULL;
 151     }
 152     return list_entry(elt, void_list_elt_t, node);
 153 }
 154
 155 void_list_elt_t *void_list_last(void_list_t *list) {
 156     struct list_head *elt;
 157     if (!list)
 158         return NULL;
 159     elt = list->head.prev;
 160     if (elt == &list->head ) {
 161         return NULL;
 162     }
 163     return list_entry(elt, void_list_elt_t, node);
 164 }
 165