~drizzle-trunk/drizzle/development

/* 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)

{

  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;

  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;

}