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

 *                                  _   _ ____  _

 *  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 "slist.h"

/* returns last node in linked list */

static struct curl_slist *slist_get_last(struct curl_slist *list)

{

  struct curl_slist *item;

  /* if caller passed us a NULL, return now */

  if(!list)

    return NULL;

  /* loop through to find the last item */

  item = list;

  while(item->next) {

    item = item->next;

  }

  return item;

}

/*

 * Curl_slist_append_nodup() appends a string to the linked list. Rather than

 * copying the string in dynamic storage, it takes its ownership. The string

 * should have been malloc()ated. Curl_slist_append_nodup always returns

 * the address of the first record, so that you can use this function as an

 * initialization function as well as an append function.

 * If an error occurs, NULL is returned and the string argument is NOT

 * released.

 */

struct curl_slist *Curl_slist_append_nodup(struct curl_slist *list,

                                           const char *data)

{

  struct curl_slist *last;

  struct curl_slist *new_item;

  DEBUGASSERT(data);

  new_item = curlx_malloc(sizeof(struct curl_slist));

  if(!new_item)

    return NULL;

  new_item->next = NULL;

  new_item->data = CURL_UNCONST(data);

  /* if this is the first item, then new_item *is* the list */

  if(!list)

    return new_item;

  last = slist_get_last(list);

  last->next = new_item;

  return list;

}

/*

 * curl_slist_append() appends a string to the linked list. It always returns

 * the address of the first record, so that you can use this function as an

 * initialization function as well as an append function. If you find this

 * bothersome, then simply create a separate _init function and call it

 * appropriately from within the program.

 */

struct curl_slist *curl_slist_append(struct curl_slist *list, const char *data)

{

  char *dupdata = curlx_strdup(data);

  if(!dupdata)

    return NULL;

  list = Curl_slist_append_nodup(list, dupdata);

  if(!list)

    curlx_free(dupdata);

  return list;

}

/*

 * Curl_slist_duplicate() duplicates a linked list. It always returns the

 * address of the first record of the cloned list or NULL in case of an

 * error (or if the input list was NULL).

 */

struct curl_slist *Curl_slist_duplicate(struct curl_slist *inlist)

{

  struct curl_slist *outlist = NULL;

  struct curl_slist *tmp;

  while(inlist) {

    tmp = curl_slist_append(outlist, inlist->data);

    if(!tmp) {

      curl_slist_free_all(outlist);

      return NULL;

    }

    outlist = tmp;

    inlist = inlist->next;

  }

  return outlist;

}

/* be nice and clean up resources */

void curl_slist_free_all(struct curl_slist *list)

{

  struct curl_slist *next;

  struct curl_slist *item;

  if(!list)

    return;

  item = list;

  do {

    next = item->next;

    Curl_safefree(item->data);

    curlx_free(item);

    item = next;

  } while(next);

}