kissgml/src/uniqstr.c

/*
 *  Copyright 2021 籽籮籮 籵籮籮籯类籲籷籰
 *
 *  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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  These are the four essential freedoms with GNU GPL software:
 *  1: freedom to run the program, for any purpose
 *  2: freedom to study how the program works, and change it to make it do what you wish
 *  3: freedom to redistribute copies to help your Free Software friends
 *  4: freedom to distribute copies of your modified versions to your Free Software friends
 *   ,           ,
 *  /             \
 * ((__-^^-,-^^-__))
 * `-_---'  `---_-'
 *  `--|o`   'o|--'
 *      \  `  /
 *       ): :(
 *       :o_o:
 *        "-"
 */

#include "config.h"

/* needed to get strdup() */
#define _GNU_SOURCE

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "splay-tree.h"
#include "main.h"
#include "uniqstr.h"

/* strdup issue here and gcc-6.3.0 */
#ifndef HAVE_STRDUP
extern char *strdup (const char *str);
#endif

static splay_tree uniqstr_splaytree = NULL;

void
clear_uniqstr (void)
{
  uniqstr_splaytree = splay_tree_delete (uniqstr_splaytree);
  return;
}

char *
uniqstr (char *str)
{
  char *s = NULL;
  splay_tree_node spn;
  if (str == NULL)
    {
      return (NULL);
    }
  if (strlen (str) == 0)
    {
      return ("");
    }
  spn = splay_tree_lookup (uniqstr_splaytree, (splay_tree_key) str);
  if (spn)
    {
      return ((char *) spn->key);
    }
  if (uniqstr_splaytree == NULL)
    {
      uniqstr_splaytree =
	splay_tree_new (splay_tree_compare_strings, splay_tree_free_key,
			NULL);
    }
  s = strdup (str);
  splay_tree_insert (uniqstr_splaytree, (splay_tree_key) s, 0);
  return (s);
}

/* end */