MGMDB/MySQL/list.c

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C
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2011-10-02 20:48:43 -05:00
/* Copyright (C) 2000 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*
Code for handling dubble-linked lists in C
*/
#include "mysys_priv.h"
#include <my_list.h>
/* Add a element to start of list */
LIST *list_add(LIST *root, LIST *element)
{
DBUG_ENTER("list_add");
DBUG_PRINT("enter",("root: 0x%lx element: 0x%lx", (long) root, (long) element));
if (root)
{
if (root->prev) /* If add in mid of list */
root->prev->next= element;
element->prev=root->prev;
root->prev=element;
}
else
element->prev=0;
element->next=root;
DBUG_RETURN(element); /* New root */
}
LIST *list_delete(LIST *root, LIST *element)
{
if (element->prev)
element->prev->next=element->next;
else
root=element->next;
if (element->next)
element->next->prev=element->prev;
return root;
}
void list_free(LIST *root, uint free_data)
{
LIST *next;
while (root)
{
next=root->next;
if (free_data)
my_free((uchar*) root->data,MYF(0));
my_free((uchar*) root,MYF(0));
root=next;
}
}
LIST *list_cons(void *data, LIST *list)
{
LIST *new_charset=(LIST*) my_malloc(sizeof(LIST),MYF(MY_FAE));
if (!new_charset)
return 0;
new_charset->data=data;
return list_add(list,new_charset);
}
LIST *list_reverse(LIST *root)
{
LIST *last;
last=root;
while (root)
{
last=root;
root=root->next;
last->next=last->prev;
last->prev=root;
}
return last;
}
uint list_length(LIST *list)
{
uint count;
for (count=0 ; list ; list=list->next, count++) ;
return count;
}
int list_walk(LIST *list, list_walk_action action, uchar* argument)
{
int error=0;
while (list)
{
if ((error = (*action)(list->data,argument)))
return error;
list=list_rest(list);
}
return 0;
}