list.c

0.5.3版本的lwip

/*
 * Copyright (c) 2001, Swedish Institute of Computer Science.
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 * 3. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE. 
 *
 * This file is part of the lwIP TCP/IP stack.
 * 
 * Author: Adam Dunkels <[e-mail]>
 *
 * $Id: list.c,v 1.1 2001/12/12 10:00:58 adam Exp $
 */


#include "lwip/list.h"

#include <stdlib.h>

struct list {
  struct elem *first, *last;
  int size, elems;
};

struct elem {
  struct elem *next;
  void *data;
};

/*-----------------------------------------------------------------------------------*/
struct list *
list_new(int size)
{
  struct list *list;
  list = malloc(sizeof(struct list));
  list->first = list->last = NULL;
  list->size = size;
  list->elems = 0;
  return list;
}
/*-----------------------------------------------------------------------------------*/
int
list_push(struct list *list, void *data)
{
  struct elem *elem;
  
  if(list->elems < list->size) {
    elem = malloc(sizeof(struct elem));
    elem->data = data;
    elem->next = NULL;
    if(list->last != NULL) {
      list->last->next = elem;
    }
    list->last = elem;
    if(list->first == NULL) {
      list->first = elem;
    }
    list->elems++;
    return 1;
  }
  return 0;
}
/*-----------------------------------------------------------------------------------*/
void *
list_pop(struct list *list)
{
  struct elem *elem;
  void *data;
  
  if(list->elems > 0) {    
    elem = list->first;
    if(elem == list->last) {
      list->last = elem->next;
    }
    list->first = elem->next;
    
    list->elems--;

    data = elem->data;
    free(elem);

    return data;
  }
  return NULL;
}
/*-----------------------------------------------------------------------------------*/
void *
list_first(struct list *list)
{
  return list->first;
}
/*-----------------------------------------------------------------------------------*/
int
list_elems(struct list *list)
{
  return list->elems;
}
/*-----------------------------------------------------------------------------------*/
void
list_delete(struct list *list)
{
  while(list_pop(list) != NULL);
  free(list);
}
/*-----------------------------------------------------------------------------------*/
int
list_remove(struct list *list, void *elem)
{
  struct elem *e, *p;
  
  p = NULL;
  for(e = list->first; e != NULL; e = e->next) {
    if(e->data == elem) {
      if(p != NULL) {
        p->next = e->next;
      } else {
        list->first = e->next;
      }
      if(list->last == e) {
        list->last = p;
        if(p != NULL) {
          p->next = NULL;
        }
      }
      free(e);
      list->elems--;
      return 1;
    } 
    p = e;    
  }
  return 0;
}
/*-----------------------------------------------------------------------------------*/
void
list_map(struct list *list, void (* func)(void *arg))
{
  struct elem *e;

  for(e = list->first; e != NULL; e = e->next) {
    func(e->data);
  }
}
/*-----------------------------------------------------------------------------------*/