ausearch-int.c

/*
* ausearch-int.c - Minimal linked list library for integers
* Copyright (c) 2005 Red Hat Inc., Durham, North Carolina.
* All Rights Reserved. 
*
* This software may be freely redistributed and/or modified under the
* terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2, or (at your option) any
* later version.
*
* 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; see the file COPYING. If not, write to the
* Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Authors:
*   Steve Grubb <sgrubb@redhat.com>
*/

#include "config.h"
#include <stdlib.h>
#include <string.h>
#include "ausearch-int.h"

void ilist_create(ilist *l)
{
      l->head = NULL;
      l->cur = NULL;
      l->cnt = 0;
}

void ilist_last(ilist *l)
{
        register int_node* window;
      
      if (l->head == NULL)
            return;

        window = l->head;
      while (window->next)
            window = window->next;
      l->cur = window;
}

int_node *ilist_next(ilist *l)
{
      if (l->cur == NULL)
            return NULL;
      l->cur = l->cur->next;
      return l->cur;
}

int_node *ilist_prev(ilist *l)
{
      if (l->cur == NULL)
            return NULL;

      if (l->cur->item <= 0)
            return NULL;

      ilist_find_item(l, l->cur->item-1);
      return l->cur;
}

void ilist_append(ilist *l, int num, unsigned int hits, int aux)
{
      int_node* newnode;

      newnode = malloc(sizeof(int_node));

      newnode->num = num;
      newnode->hits = hits;
      newnode->aux1 = aux;
      newnode->item = l->cnt; 
      newnode->next = NULL;

      // if we are at top, fix this up
      if (l->head == NULL)
            l->head = newnode;
      else  // Otherwise add pointer to newnode
            l->cur->next = newnode;

      // make newnode current
      l->cur = newnode;
      l->cnt++;
}

int ilist_find_item(ilist *l, unsigned int i)
{
        register int_node* window;
                                                                                
      if (l->cur && (l->cur->item <= i))
            window = l->cur;  /* Try to use where we are */
      else
            window = l->head; /* Can't, start over */

      while (window) {
            if (window->item == i) {
                  l->cur = window;
                  return 1;
            }
            else
                  window = window->next;
      }
      return 0;
}

void ilist_clear(ilist* l)
{
      int_node* nextnode;
      register int_node* current;

      if (l == NULL)
            return;

      current = l->head;
      while (current) {
            nextnode=current->next;
            free(current);
            current=nextnode;
      }
      l->head = NULL;
      l->cur = NULL;
      l->cnt = 0;
}

int ilist_add_if_uniq(ilist *l, int num, int aux)
{
      register int_node* cur;

      cur = l->head;
      while (cur) {
            if (cur->num == num) {
                  cur->hits++;
                  return 0;
            }
            else
                  cur = cur->next;
      }

      /* No matches, append to the end */
      ilist_append(l, num, 1, aux);
      return 1;
}

void ilist_sort_by_hits(ilist *l)
{
      register int_node* cur, *prev = NULL;

      if (l->cnt <= 1)
            return;

      cur = l->head;

      /* Make sure l->cur points to end */
      if (l->cur->next != NULL) {
            prev = l->cur->next;
            while (prev->next)
                  prev = prev->next;
            l->cur = prev;
      }

      while (cur && cur->next) {
            /* If the next node is bigger */
            if (cur->hits < cur->next->hits) {
                  // detach node
                  if (l->head == cur)
                        l->head = cur->next;
                  if (prev)
                        prev->next = cur->next;
                  else
                        prev = cur->next;

                  // append
                  ilist_append(l, cur->num, cur->hits, cur->aux1);
                  free(cur);

                  // start over
                  cur = l->head;
                  prev = NULL;
                  continue;
            }
            prev = cur;
            cur = cur->next;
      }
}