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/* $Id: anonymous.c,v 1.1 2000-03-31 19:56:55 rjkaes Exp $
*
* Handles insertion and searches for headers which should be let through when
* the anonymous feature is turned on. The headers are stored in a Ternary
* Search Tree. The initial code came from Dr. Dobb's Journal, April 1998
* "Ternary Search Trees", Jon Bentley and Bob Sedgewick, pg 20-25.
*
* Copyright (C) 2000 Robert James Kaes (rjkaes@flarenet.com)
*
* 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 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.
*/
#ifdef HAVE_CONFIG_H
#include <defines.h>
#endif
#include <stdlib.h>
#include <ctype.h>
#include "anonymous.h"
typedef struct tnode *Tptr;
typedef struct tnode {
char splitchar;
Tptr lokid, eqkid, hikid;
} Tnode;
static Tptr anon_root = NULL;
static Tptr intern_insert(Tptr p, char *s)
{
if (p == NULL) {
p = (Tptr) malloc(sizeof(Tnode));
p->splitchar = tolower(*s);
p->lokid = p->eqkid = p->hikid = NULL;
}
if (tolower(*s) < p->splitchar)
p->lokid = intern_insert(p->lokid, s);
else if (tolower(*s) == p->splitchar) {
if (tolower(*s) != 0)
p->eqkid = intern_insert(p->eqkid, ++s);
} else
p->hikid = intern_insert(p->hikid, s);
return p;
}
int anon_search(char *s)
{
Tptr p = anon_root;
while (p) {
if (tolower(*s) < p->splitchar)
p = p->lokid;
else if (tolower(*s) == p->splitchar) {
if (*s++ == 0)
return 1;
p = p->eqkid;
} else
p = p->hikid;
}
return 0;
}
void anon_insert(char *s)
{
anon_root = intern_insert(anon_root, s);
}
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