/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

#include "curl_setup.h"

#include <curl/curl.h>

#include "llist.h"

#include "curl_memory.h"

/* this must be the last include file */

#include "memdebug.h"

/*

 * @unittest: 1300

 */

void

Curl_llist_init(struct Curl_llist *l, Curl_llist_dtor dtor)

{

  l->size = 0;

  l->dtor = dtor;

  l->head = NULL;

  l->tail = NULL;

}

/*

 * Curl_llist_insert_next()

 *

 * Inserts a new list element after the given one 'e'. If the given existing

 * entry is NULL and the list already has elements, the new one will be

 * inserted first in the list.

 *

 * The 'ne' argument should be a pointer into the object to store.

 *

 * @unittest: 1300

 */

void

Curl_llist_insert_next(struct Curl_llist *list, struct Curl_llist_element *e,

                       const void *p,

                       struct Curl_llist_element *ne)

{

  ne->ptr = (void *) p;

  if(list->size == 0) {

    list->head = ne;

    list->head->prev = NULL;

    list->head->next = NULL;

    list->tail = ne;

  }

  else {

    /* if 'e' is NULL here, we insert the new element first in the list */

    ne->next = e?e->next:list->head;

    ne->prev = e;

    if(!e) {

      list->head->prev = ne;

      list->head = ne;

    }

    else if(e->next) {

      e->next->prev = ne;

    }

    else {

      list->tail = ne;

    }

    if(e)

      e->next = ne;

  }

  ++list->size;

}

/*

 * @unittest: 1300

 */

void

Curl_llist_remove(struct Curl_llist *list, struct Curl_llist_element *e,

                  void *user)

{

  void *ptr;

  if(!e || list->size == 0)

    return;

  if(e == list->head) {

    list->head = e->next;

    if(!list->head)

      list->tail = NULL;

    else

      e->next->prev = NULL;

  }

  else {

    if(e->prev)

      e->prev->next = e->next;

    if(!e->next)

      list->tail = e->prev;

    else

      e->next->prev = e->prev;

  }

  ptr = e->ptr;

  e->ptr  = NULL;

  e->prev = NULL;

  e->next = NULL;

  --list->size;

  /* call the dtor() last for when it actually frees the 'e' memory itself */

  if(list->dtor)

    list->dtor(user, ptr);

}

void

Curl_llist_destroy(struct Curl_llist *list, void *user)

{

  if(list) {

    while(list->size > 0)

      Curl_llist_remove(list, list->tail, user);

  }

}

size_t

Curl_llist_count(struct Curl_llist *list)

{

  return list->size;

}