dep/mysqllite/mysys/list.c

   1 /* Copyright (C) 2000 MySQL AB
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 of the License.
   6
   7    This program is distributed in the hope that it will be useful,
   8    but WITHOUT ANY WARRANTY; without even the implied warranty of
   9    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10    GNU General Public License for more details.
  11
  12    You should have received a copy of the GNU General Public License
  13    along with this program; if not, write to the Free Software
  14    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
  15
  16 /*
  17   Code for handling dubble-linked lists in C
  18 */
  19
  20 #include "mysys_priv.h"
  21 #include <my_list.h>
  22
  23
  24
  25         /* Add a element to start of list */
  26
  27 LIST *list_add(LIST *root, LIST *element)
  28 {
  29   DBUG_ENTER("list_add");
  30   DBUG_PRINT("enter",("root: 0x%lx  element: 0x%lx", (long) root, (long) element));
  31   if (root)
  32   {
  33     if (root->prev)                     /* If add in mid of list */
  34       root->prev->next= element;
  35     element->prev=root->prev;
  36     root->prev=element;
  37   }
  38   else
  39     element->prev=0;
  40   element->next=root;
  41   DBUG_RETURN(element);                 /* New root */
  42 }
  43
  44
  45 LIST *list_delete(LIST *root, LIST *element)
  46 {
  47   if (element->prev)
  48     element->prev->next=element->next;
  49   else
  50     root=element->next;
  51   if (element->next)
  52     element->next->prev=element->prev;
  53   return root;
  54 }
  55
  56
  57 void list_free(LIST *root, uint free_data)
  58 {
  59   LIST *next;
  60   while (root)
  61   {
  62     next=root->next;
  63     if (free_data)
  64       my_free((uchar*) root->data,MYF(0));
  65     my_free((uchar*) root,MYF(0));
  66     root=next;
  67   }
  68 }
  69
  70
  71 LIST *list_cons(void *data, LIST *list)
  72 {
  73   LIST *new_charset=(LIST*) my_malloc(sizeof(LIST),MYF(MY_FAE));
  74   if (!new_charset)
  75     return 0;
  76   new_charset->data=data;
  77   return list_add(list,new_charset);
  78 }
  79
  80
  81 LIST *list_reverse(LIST *root)
  82 {
  83   LIST *last;
  84
  85   last=root;
  86   while (root)
  87   {
  88     last=root;
  89     root=root->next;
  90     last->next=last->prev;
  91     last->prev=root;
  92   }
  93   return last;
  94 }
  95
  96 uint list_length(LIST *list)
  97 {
  98   uint count;
  99   for (count=0 ; list ; list=list->next, count++) ;
 100   return count;
 101 }
 102
 103
 104 int list_walk(LIST *list, list_walk_action action, uchar* argument)
 105 {
 106   int error=0;
 107   while (list)
 108   {
 109     if ((error = (*action)(list->data,argument)))
 110       return error;
 111     list=list_rest(list);
 112   }
 113   return 0;
 114 }