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 "includes.h"
  19 #include <errno.h>
  20
  21 #include "void_list.h"
  22 #include "libbb/libbb.h"
  23
  24 void void_list_elt_init(void_list_elt_t *elt, void *data)
  25 {
  26     INIT_LIST_HEAD(&elt->node);
  27     elt->data = data;
  28 }
  29
  30 void_list_elt_t * void_list_elt_new (void *data) {
  31     void_list_elt_t *elt;
  32     /* freed in void_list_elt_deinit */
  33     elt = xcalloc(1, sizeof(void_list_elt_t));
  34     void_list_elt_init(elt, data);
  35     return elt;
  36 }
  37
  38 void void_list_elt_deinit(void_list_elt_t *elt)
  39 {
  40     list_del_init(&elt->node);
  41     void_list_elt_init(elt, NULL);
  42     free(elt);
  43 }
  44
  45 void void_list_init(void_list_t *list)
  46 {
  47     INIT_LIST_HEAD(&list->head);
  48 }
  49
  50 void void_list_deinit(void_list_t *list)
  51 {
  52     void_list_elt_t *elt;
  53
  54     while (!void_list_empty(list)) {
  55         elt = void_list_pop(list);
  56         void_list_elt_deinit(elt);
  57     }
  58     INIT_LIST_HEAD(&list->head);
  59 }
  60
  61 void void_list_append(void_list_t *list, void *data)
  62 {
  63     void_list_elt_t *elt = void_list_elt_new(data);
  64     list_add_tail(&elt->node, &list->head);
  65 }
  66
  67 void void_list_push(void_list_t *list, void *data)
  68 {
  69     void_list_elt_t *elt = void_list_elt_new(data);
  70     list_add(&elt->node, &list->head);
  71 }
  72
  73 void_list_elt_t *void_list_pop(void_list_t *list)
  74 {
  75     struct list_head *node;
  76
  77     if (void_list_empty(list))
  78         return NULL;
  79     node = list->head.next;
  80     list_del_init(node);
  81     return list_entry(node, void_list_elt_t, node);
  82 }
  83
  84 void *void_list_remove(void_list_t *list, void_list_elt_t **iter)
  85 {
  86     void_list_elt_t *pos, *n;
  87     void_list_elt_t *old_elt;
  88     void *old_data = NULL;
  89
  90     old_elt = *iter;
  91     if (!old_elt)
  92         return old_data;
  93     old_data = old_elt->data;
  94
  95     list_for_each_entry_safe(pos, n, &list->head, node) {
  96         if (pos == old_elt)
  97             break;
  98     }
  99     if ( pos != old_elt) {
 100         fprintf(stderr, "%s: ERROR: element not found in list\n", __FUNCTION__);
 101         return NULL;
 102     }
 103
 104     *iter = list_entry(pos->node.prev, void_list_elt_t, node);
 105     void_list_elt_deinit(pos);
 106
 107     return old_data;
 108 }
 109
 110 /* remove element containing elt data, using cmp(elt->data, target_data) == 0. */
 111 void *void_list_remove_elt(void_list_t *list, const void *target_data, void_list_cmp_t cmp)
 112 {
 113     void_list_elt_t *pos, *n;
 114     void *old_data = NULL;
 115     list_for_each_entry_safe(pos, n, &list->head, node) {
 116         if ( pos->data && cmp(pos->data, target_data)==0 ){
 117             old_data = pos->data;
 118             void_list_elt_deinit(pos);
 119             break;
 120         }
 121     }
 122     return old_data;
 123 }
 124
 125 void_list_elt_t *void_list_first(void_list_t *list) {
 126     struct list_head *elt;
 127     if (!list)
 128         return NULL;
 129     elt = list->head.next;
 130     if (elt == &list->head ) {
 131         return NULL;
 132     }
 133     return list_entry(elt, void_list_elt_t, node);
 134 }
 135
 136 void_list_elt_t *void_list_prev(void_list_t *list, void_list_elt_t *node) {
 137     struct list_head *elt;
 138     if (!list || !node)
 139         return NULL;
 140     elt = node->node.prev;
 141     if (elt == &list->head ) {
 142         return NULL;
 143     }
 144     return list_entry(elt, void_list_elt_t, node);
 145 }
 146
 147 void_list_elt_t *void_list_next(void_list_t *list, void_list_elt_t *node) {
 148     struct list_head *elt;
 149     if (!list || !node)
 150         return NULL;
 151     elt = node->node.next;
 152     if (elt == &list->head ) {
 153         return NULL;
 154     }
 155     return list_entry(elt, void_list_elt_t, node);
 156 }
 157
 158 void_list_elt_t *void_list_last(void_list_t *list) {
 159     struct list_head *elt;
 160     if (!list)
 161         return NULL;
 162     elt = list->head.prev;
 163     if (elt == &list->head ) {
 164         return NULL;
 165     }
 166     return list_entry(elt, void_list_elt_t, node);
 167 }
 168