list.c 2.37 KB
Newer Older
unknown's avatar
unknown committed
1 2 3 4 5 6 7 8
/* 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; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
unknown's avatar
unknown committed
9
   but WITHOUT ANY WARRANTY; without even the implied warranty of
unknown's avatar
unknown committed
10 11 12 13 14 15
   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 */
unknown's avatar
unknown committed
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

/*
  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: %lx  element: %lx", root, 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;
}


58
void list_free(LIST *root, uint free_data)
unknown's avatar
unknown committed
59 60 61 62 63 64 65 66 67 68 69 70 71 72 73
{
  LIST *next;
  while (root)
  {
    next=root->next;
    if (free_data)
      my_free((gptr) root->data,MYF(0));
    my_free((gptr) root,MYF(0));
    root=next;
  }
}


LIST *list_cons(void *data, LIST *list)
{
unknown's avatar
unknown committed
74 75
  LIST *new_charset=(LIST*) my_malloc(sizeof(LIST),MYF(MY_FAE));
  if (!new_charset)
unknown's avatar
unknown committed
76
    return 0;
unknown's avatar
unknown committed
77 78
  new_charset->data=data;
  return list_add(list,new_charset);
unknown's avatar
unknown committed
79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115
}


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, gptr argument)
{
  int error=0;
  while (list)
  {
    if ((error = (*action)(list->data,argument)))
      return error;
    list=rest(list);
  }
  return 0;
}