/*
* lftp - file transfer program
*
* Copyright (c) 1996-2013 by Alexander V. Lukyanov (lav@yars.free.net)
*
* 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/>.
*/
#ifndef XLIST_H
#define XLIST_H 1
// this list implementation is based on linux kernel idea of lists
#include <stddef.h>
#include <assert.h>
template<class T> class xlist
{
xlist<T> *next;
xlist<T> *prev;
T *obj;
static void _add(xlist<T> *node,xlist<T> *prev,xlist<T> *next) {
next->prev=node;
node->next=next;
node->prev=prev;
prev->next=node;
}
static void _del(xlist<T> *prev,xlist<T> *next) {
next->prev=prev;
prev->next=next;
}
protected:
xlist() : next(this), prev(this), obj(0) {}
public:
xlist(T *t) : next(0), prev(0), obj(t) {}
void add(xlist<T> *node) {
assert(!node->next && !node->prev);
_add(node,this,next);
}
void add(xlist<T>& node) { add(&node); }
void add_tail(xlist<T> *node) {
assert(!node->next && !node->prev);
_add(node,prev,this);
}
void add_tail(xlist<T>& node) { add_tail(&node); }
void remove() {
_del(prev,next);
next=prev=0;
}
xlist<T> *get_next() const { return next; }
xlist<T> *get_prev() const { return prev; }
T *get_obj() const { return obj; }
T *next_obj() const { return next->obj; }
int count() const {
int count=0;
for(xlist<T> *scan=next; scan!=this; scan=scan->next)
count++;
return count;
}
bool listed() const {
return next!=0;
}
};
template<class T> class xlist_head : public xlist<T>
{
public:
xlist_head() {}
T *first_obj() const { return xlist<T>::next_obj(); }
};
#define xlist_for_each(TYPE,list_head,node,obj) \
TYPE *obj; \
for(xlist<TYPE> *node=(list_head).get_next(); obj=node->get_obj(), node!=&list_head; node=node->get_next())
#define xlist_for_each_safe(TYPE,list_head,node,obj,next) \
TYPE *obj; \
for(xlist<TYPE> *node=(list_head).get_next(), *next=node->get_next(); obj=node->get_obj(), node!=&list_head; node=next, next=node->get_next())
#endif//XLIST_H