1// vi:set ft=cpp: -*- Mode: C++ -*-
2/*
3 * (c) 2011 Alexander Warg <warg@os.inf.tu-dresden.de>
4 *     economic rights: Technische Universität Dresden (Germany)
5 *
6 * This file is part of TUD:OS and distributed under the terms of the
7 * GNU General Public License 2.
8 * Please see the COPYING-GPL-2 file for details.
9 *
10 * As a special exception, you may use this file as part of a free software
11 * library without restriction.  Specifically, if other files instantiate
12 * templates or use macros or inline functions from this file, or you compile
13 * this file and link it with other files to produce an executable, this
14 * file does not by itself cause the resulting executable to be covered by
15 * the GNU General Public License.  This exception does not however
16 * invalidate any other reasons why the executable file might be covered by
17 * the GNU General Public License.
18 */
19
20#pragma once
21
22namespace cxx {
23
24class D_list_item
25{
26public:
27  D_list_item() : _dli_next(0) {}
28private:
29  friend class D_list_item_policy;
30
31  D_list_item(D_list_item const &);
32  void operator = (D_list_item const &);
33
34  D_list_item *_dli_next, *_dli_prev;
35};
36
37class D_list_item_policy
38{
39public:
40  typedef D_list_item Item;
41  static D_list_item *&prev(D_list_item *e) { return e->_dli_prev; }
42  static D_list_item *&next(D_list_item *e) { return e->_dli_next; }
43  static D_list_item *prev(D_list_item const *e) { return e->_dli_prev; }
44  static D_list_item *next(D_list_item const *e) { return e->_dli_next; }
45};
46
47template< typename T >
48struct Sd_list_head_policy
49{
50  typedef T *Head_type;
51  static T *head(Head_type h) { return h; }
52  static void set_head(Head_type &h, T *v) { h = v; }
53};
54
55template<
56  typename T,
57  typename C = D_list_item_policy
58>
59class D_list_cyclic
60{
61protected:
62  template< typename VALUE, typename ITEM >
63  class __Iterator
64  {
65  public:
66    typedef VALUE *Value_type;
67    typedef VALUE *value_type;
68
69    __Iterator() {}
70
71    bool operator == (__Iterator const &o) const
72    { return _c == o._c; }
73
74    bool operator != (__Iterator const &o) const
75    { return _c != o._c; }
76
77    __Iterator &operator ++ ()
78    {
79      _c = C::next(_c);
80      return *this;
81    }
82
83    __Iterator &operator -- ()
84    {
85      _c = C::prev(_c);
86      return *this;
87    }
88
89    Value_type operator * () const { return static_cast<Value_type>(_c); }
90    Value_type operator -> () const { return static_cast<Value_type>(_c); }
91
92  private:
93    friend class D_list_cyclic;
94
95    explicit __Iterator(ITEM *s) : _c(s) {}
96
97    ITEM *_c;
98  };
99
100public:
101  typedef T *Value_type;
102  typedef T *value_type;
103  typedef __Iterator<T, typename C::Item> Iterator;
104  typedef Iterator Const_iterator;
105
106  static void remove(T *e)
107  {
108    C::next(C::prev(e)) = C::next(e);
109    C::prev(C::next(e)) = C::prev(e);
110    C::next(e) = 0;
111  }
112
113  static Iterator erase(Iterator const &e)
114  {
115    typename C::Item *n = C::next(*e);
116    remove(*e);
117    return __iter(n);
118  }
119
120  static Iterator iter(T const *e) { return Iterator(const_cast<T*>(e)); }
121
122  static bool in_list(T const *e) { return C::next(const_cast<T*>(e)); }
123  static bool has_sibling(T const *e) { return C::next(const_cast<T*>(e)) != e; }
124
125  static Iterator insert_after(T *e, Iterator const &pos)
126  {
127    C::prev(e) = *pos;
128    C::next(e) = C::next(*pos);
129    C::prev(C::next(*pos)) = e;
130    C::next(*pos) = e;
131    return pos;
132  }
133
134  static Iterator insert_before(T *e, Iterator const &pos)
135  {
136    C::next(e) = *pos;
137    C::prev(e) = C::prev(*pos);
138    C::next(C::prev(*pos)) = e;
139    C::prev(*pos) = e;
140    return pos;
141  }
142
143  static T *self_insert(T *e)
144  { C::next(e) = C::prev(e) = e; return e; }
145
146  static void remove_last(T *e)
147  { C::next(e) = 0; }
148
149protected:
150  static Iterator __iter(typename C::Item *e) { return Iterator(e); }
151};
152
153template<
154  typename T,
155  typename C = D_list_item_policy,
156  typename H = Sd_list_head_policy<T>,
157  bool BSS = false
158>
159class Sd_list : public D_list_cyclic<T, C>
160{
161private:
162  typedef D_list_cyclic<T, C> Base;
163
164public:
165  typedef typename Base::Iterator Iterator;
166  enum Pos
167  { Back, Front };
168
169  Sd_list() { if (!BSS) H::set_head(_f, 0); }
170
171  bool empty() const { return !H::head(_f); }
172  T *front() const { return H::head(_f); }
173
174  void remove(T *e)
175  {
176    T *h = H::head(_f);
177    if (e == C::next(e)) // must be the last
178      {
179        Base::remove_last(e);
180        H::set_head(_f, 0);
181        return;
182      }
183
184    if (e == H::head(_f))
185      H::set_head(_f, static_cast<T*>(C::next(h)));
186
187    Base::remove(e);
188  }
189
190  Iterator erase(Iterator const &e)
191  {
192    typename C::Item *n = C::next(*e);
193    remove(*e);
194    return __iter(n);
195  }
196
197  void push(T *e, Pos pos)
198  {
199    T *h = H::head(_f);
200    if (!h)
201      H::set_head(_f, Base::self_insert(e));
202    else
203      {
204        Base::insert_before(e, this->iter(h));
205        if (pos == Front)
206          H::set_head(_f, e);
207      }
208  }
209
210  void push_back(T *e) { push(e, Back); }
211  void push_front(T *e) { push(e, Front); }
212  void rotate_to(T *h) { H::set_head(_f, h); }
213
214  typename H::Head_type const &head() const { return _f; }
215  typename H::Head_type &head() { return _f; }
216
217private:
218  Sd_list(Sd_list const &);
219  void operator = (Sd_list const &);
220
221  typename H::Head_type _f;
222};
223
224template<
225  typename T,
226  typename C = D_list_item_policy,
227  bool BSS = false
228>
229class D_list : public D_list_cyclic<T, C>
230{
231private:
232  typedef D_list_cyclic<T, C> Base;
233  typedef typename C::Item Internal_type;
234
235public:
236  enum Pos
237  { Back, Front };
238
239  typedef typename Base::Iterator Iterator;
240  typedef typename Base::Const_iterator Const_iterator;
241  typedef T* value_type;
242  typedef T* Value_type;
243
244  D_list() { this->self_insert(static_cast<T*>(&_h)); }
245
246  bool empty() const { return C::next(static_cast<T const *>(&_h)) == &_h; }
247
248  static void remove(T *e) { Base::remove(e); }
249  Iterator erase(Iterator const &e) { return Base::erase(e); }
250
251  void push(T *e, Pos pos)
252  {
253    if (pos == Front)
254      Base::insert_after(e, end());
255    else
256      Base::insert_before(e, end());
257  }
258
259  void push_back(T *e) { push(e, Back); }
260  void push_front(T *e) { push(e, Front); }
261
262  Iterator begin() const { return this->__iter(C::next(const_cast<Internal_type *>(&_h))); }
263  Iterator end() const { return this->__iter(const_cast<Internal_type *>(&_h)); }
264
265private:
266  D_list(D_list const &);
267  void operator = (D_list const &);
268
269  Internal_type _h;
270};
271
272}
273
274