stl_deque.h

著名的SGI的STL lib源码.(C++范型类编成,没有合适的分类,但是放到数据结构类别中也绝对适合)

  void push_front(const value_type& t) {
    if (start.cur != start.first) {
      construct(start.cur - 1, t);
      --start.cur;
    }
    else
      push_front_aux(t);
  }

  void pop_back() {
    if (finish.cur != finish.first) {
      --finish.cur;
      destroy(finish.cur);
    }
    else
      pop_back_aux();
  }

  void pop_front() {
    if (start.cur != start.last - 1) {
      destroy(start.cur);
      ++start.cur;
    }
    else 
      pop_front_aux();
  }

public:                         // Insert

  iterator insert(iterator position, const value_type& x) {
    if (position.cur == start.cur) {
      push_front(x);
      return start;
    }
    else if (position.cur == finish.cur) {
      push_back(x);
      iterator tmp = finish;
      --tmp;
      return tmp;
    }
    else {
      return insert_aux(position, x);
    }
  }

  iterator insert(iterator position) { return insert(position, value_type()); }

  void insert(iterator pos, size_type n, const value_type& x); 

  void insert(iterator pos, int n, const value_type& x) {
    insert(pos, (size_type) n, x);
  }
  void insert(iterator pos, long n, const value_type& x) {
    insert(pos, (size_type) n, x);
  }

#ifdef __STL_MEMBER_TEMPLATES  

  template <class InputIterator>
  void insert(iterator pos, InputIterator first, InputIterator last) {
    insert(pos, first, last, iterator_category(first));
  }

#else /* __STL_MEMBER_TEMPLATES */

  void insert(iterator pos, const value_type* first, const value_type* last);
  void insert(iterator pos, const_iterator first, const_iterator last);

#endif /* __STL_MEMBER_TEMPLATES */

  void resize(size_type new_size, const value_type& x) {
    const size_type len = size();
    if (new_size < len) 
      erase(start + new_size, finish);
    else
      insert(finish, new_size - len, x);
  }

  void resize(size_type new_size) { resize(new_size, value_type()); }

public:                         // Erase
  iterator erase(iterator pos) {
    iterator next = pos;
    ++next;
    difference_type index = pos - start;
    if (index < (size() >> 1)) {
      copy_backward(start, pos, next);
      pop_front();
    }
    else {
      copy(next, finish, pos);
      pop_back();
    }
    return start + index;
  }

  iterator erase(iterator first, iterator last);
  void clear(); 

protected:                        // Internal construction/destruction

  void create_map_and_nodes(size_type num_elements);
  void destroy_map_and_nodes();
  void fill_initialize(size_type n, const value_type& value);

#ifdef __STL_MEMBER_TEMPLATES  

  template <class InputIterator>
  void range_initialize(InputIterator first, InputIterator last,
                        input_iterator_tag);

  template <class ForwardIterator>
  void range_initialize(ForwardIterator first, ForwardIterator last,
                        forward_iterator_tag);

#endif /* __STL_MEMBER_TEMPLATES */

protected:                        // Internal push_* and pop_*

  void push_back_aux(const value_type& t);
  void push_front_aux(const value_type& t);
  void pop_back_aux();
  void pop_front_aux();

protected:                        // Internal insert functions

#ifdef __STL_MEMBER_TEMPLATES  

  template <class InputIterator>
  void insert(iterator pos, InputIterator first, InputIterator last,
              input_iterator_tag);

  template <class ForwardIterator>
  void insert(iterator pos, ForwardIterator first, ForwardIterator last,
              forward_iterator_tag);

#endif /* __STL_MEMBER_TEMPLATES */

  iterator insert_aux(iterator pos, const value_type& x);
  void insert_aux(iterator pos, size_type n, const value_type& x);

#ifdef __STL_MEMBER_TEMPLATES  

  template <class ForwardIterator>
  void insert_aux(iterator pos, ForwardIterator first, ForwardIterator last,
                  size_type n);

#else /* __STL_MEMBER_TEMPLATES */
  
  void insert_aux(iterator pos,
                  const value_type* first, const value_type* last,
                  size_type n);

  void insert_aux(iterator pos, const_iterator first, const_iterator last,
                  size_type n);
 
#endif /* __STL_MEMBER_TEMPLATES */

  iterator reserve_elements_at_front(size_type n) {
    size_type vacancies = start.cur - start.first;
    if (n > vacancies) 
      new_elements_at_front(n - vacancies);
    return start - difference_type(n);
  }

  iterator reserve_elements_at_back(size_type n) {
    size_type vacancies = (finish.last - finish.cur) - 1;
    if (n > vacancies)
      new_elements_at_back(n - vacancies);
    return finish + difference_type(n);
  }

  void new_elements_at_front(size_type new_elements);
  void new_elements_at_back(size_type new_elements);

  void destroy_nodes_at_front(iterator before_start);
  void destroy_nodes_at_back(iterator after_finish);

protected:                      // Allocation of map and nodes

  // Makes sure the map has space for new nodes.  Does not actually
  //  add the nodes.  Can invalidate map pointers.  (And consequently, 
  //  deque iterators.)

  void reserve_map_at_back (size_type nodes_to_add = 1) {
    if (nodes_to_add + 1 > map_size - (finish.node - map))
      reallocate_map(nodes_to_add, false);
  }

  void reserve_map_at_front (size_type nodes_to_add = 1) {
    if (nodes_to_add > start.node - map)
      reallocate_map(nodes_to_add, true);
  }

  void reallocate_map(size_type nodes_to_add, bool add_at_front);

  pointer allocate_node() { return data_allocator::allocate(buffer_size()); }
  void deallocate_node(pointer n) {
    data_allocator::deallocate(n, buffer_size());
  }

#ifdef __STL_NON_TYPE_TMPL_PARAM_BUG
public:
  bool operator==(const deque<T, Alloc, 0>& x) const {
    return size() == x.size() && equal(begin(), end(), x.begin());
  }
  bool operator!=(const deque<T, Alloc, 0>& x) const {
    return size() != x.size() || !equal(begin(), end(), x.begin());
  }
  bool operator<(const deque<T, Alloc, 0>& x) const {
    return lexicographical_compare(begin(), end(), x.begin(), x.end());
  }
#endif /* __STL_NON_TYPE_TMPL_PARAM_BUG */
};

// Non-inline member functions

template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::insert(iterator pos,
                                      size_type n, const value_type& x) {
  if (pos.cur == start.cur) {
    iterator new_start = reserve_elements_at_front(n);
    uninitialized_fill(new_start, start, x);
    start = new_start;
  }
  else if (pos.cur == finish.cur) {
    iterator new_finish = reserve_elements_at_back(n);
    uninitialized_fill(finish, new_finish, x);
    finish = new_finish;
  }
  else 
    insert_aux(pos, n, x);
}

#ifndef __STL_MEMBER_TEMPLATES  

template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::insert(iterator pos,
                                      const value_type* first,
                                      const value_type* last) {
  size_type n = last - first;
  if (pos.cur == start.cur) {
    iterator new_start = reserve_elements_at_front(n);
    __STL_TRY {
      uninitialized_copy(first, last, new_start);
      start = new_start;
    }
    __STL_UNWIND(destroy_nodes_at_front(new_start));
  }
  else if (pos.cur == finish.cur) {
    iterator new_finish = reserve_elements_at_back(n);
    __STL_TRY {
      uninitialized_copy(first, last, finish);
      finish = new_finish;
    }
    __STL_UNWIND(destroy_nodes_at_back(new_finish));
  }
  else
    insert_aux(pos, first, last, n);
}

template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::insert(iterator pos,
                                      const_iterator first,
                                      const_iterator last)
{
  size_type n = last - first;
  if (pos.cur == start.cur) {
    iterator new_start = reserve_elements_at_front(n);
    __STL_TRY {
      uninitialized_copy(first, last, new_start);
      start = new_start;
    }
    __STL_UNWIND(destroy_nodes_at_front(new_start));
  }
  else if (pos.cur == finish.cur) {
    iterator new_finish = reserve_elements_at_back(n);
    __STL_TRY {
      uninitialized_copy(first, last, finish);
      finish = new_finish;
    }
    __STL_UNWIND(destroy_nodes_at_back(new_finish));
  }
  else
    insert_aux(pos, first, last, n);
}

#endif /* __STL_MEMBER_TEMPLATES */

template <class T, class Alloc, size_t BufSize>
deque<T, Alloc, BufSize>::iterator 
deque<T, Alloc, BufSize>::erase(iterator first, iterator last) {
  if (first == start && last == finish) {
    clear();
    return finish;
  }
  else {
    difference_type n = last - first;
    difference_type elems_before = first - start;
    if (elems_before < (size() - n) / 2) {
      copy_backward(start, first, last);
      iterator new_start = start + n;
      destroy(start, new_start);
      for (map_pointer cur = start.node; cur < new_start.node; ++cur)
        data_allocator::deallocate(*cur, buffer_size());
      start = new_start;
    }
    else {
      copy(last, finish, first);
      iterator new_finish = finish - n;
      destroy(new_finish, finish);
      for (map_pointer cur = new_finish.node + 1; cur <= finish.node; ++cur)
        data_allocator::deallocate(*cur, buffer_size());
      finish = new_finish;
    }
    return start + elems_before;
  }
}

template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::clear() {
  for (map_pointer node = start.node + 1; node < finish.node; ++node) {
    destroy(*node, *node + buffer_size());
    data_allocator::deallocate(*node, buffer_size());
  }

  if (start.node != finish.node) {
    destroy(start.cur, start.last);
    destroy(finish.first, finish.cur);
    data_allocator::deallocate(finish.first, buffer_size());
  }
  else
    destroy(start.cur, finish.cur);

  finish = start;
}

template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::create_map_and_nodes(size_type num_elements) {
  size_type num_nodes = num_elements / buffer_size() + 1;

  map_size = max(initial_map_size(), num_nodes + 2);
  map = map_allocator::allocate(map_size);

  map_pointer nstart = map + (map_size - num_nodes) / 2;
  map_pointer nfinish = nstart + num_nodes - 1;
    
  map_pointer cur;
  __STL_TRY {
    for (cur = nstart; cur <= nfinish; ++cur)
      *cur = allocate_node();
  }
#     ifdef  __STL_USE_EXCEPTIONS 
  catch(...) {
    for (map_pointer n = nstart; n < cur; ++n)
      deallocate_node(*n);
    map_allocator::deallocate(map, map_size);
    throw;
  }
#     endif /* __STL_USE_EXCEPTIONS */

  start.set_node(nstart);
  finish.set_node(nfinish);
  start.cur = start.first;
  finish.cur = finish.first + num_elements % buffer_size();
}

// This is only used as a cleanup function in catch clauses.
template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::destroy_map_and_nodes() {
  for (map_pointer cur = start.node; cur <= finish.node; ++cur)
    deallocate_node(*cur);
  map_allocator::deallocate(map, map_size);
}
  

template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::fill_initialize(size_type n,
                                               const value_type& value) {
  create_map_and_nodes(n);
  map_pointer cur;
  __STL_TRY {
    for (cur = start.node; cur < finish.node; ++cur)
      uninitialized_fill(*cur, *cur + buffer_size(), value);
    uninitialized_fill(finish.first, finish.cur, value);
  }
#       ifdef __STL_USE_EXCEPTIONS
  catch(...) {
    for (map_pointer n = start.node; n < cur; ++n)
      destroy(*n, *n + buffer_size());
    destroy_map_and_nodes();
    throw;
  }
#       endif /* __STL_USE_EXCEPTIONS */
}

#ifdef __STL_MEMBER_TEMPLATES  

template <class T, class Alloc, size_t BufSize>
template <class InputIterator>
void deque<T, Alloc, BufSize>::range_initialize(InputIterator first,
                                                InputIterator last,
                                                input_iterator_tag) {
  create_map_and_nodes(0);
  for ( ; first != last; ++first)
    push_back(*first);
}

template <class T, class Alloc, size_t BufSize>
template <class ForwardIterator>
void deque<T, Alloc, BufSize>::range_initialize(ForwardIterator first,
                                                ForwardIterator last,
                                                forward_iterator_tag) {
  size_type n = 0;
  distance(first, last, n);
  create_map_and_nodes(n);
  __STL_TRY {
    uninitialized_copy(first, last, start);
  }
  __STL_UNWIND(destroy_map_and_nodes());
}

#endif /* __STL_MEMBER_TEMPLATES */

// Called only if finish.cur == finish.last - 1.
template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::push_back_aux(const value_type& t) {
  value_type t_copy = t;
  reserve_map_at_back();
  *(finish.node + 1) = allocate_node();
  __STL_TRY {
    construct(finish.cur, t_copy);
    finish.set_node(finish.node + 1);
    finish.cur = finish.first;
  }
  __STL_UNWIND(deallocate_node(*(finish.node + 1)));
}

// Called only if start.cur == start.first.
template <class T, class Alloc, size_t BufSize>
void deque<T, Alloc, BufSize>::push_front_aux(const value_type& t) {
  value_type t_copy = t;
  reserve_map_at_front();
  *(start.node - 1) = allocate_node();
  __STL_TRY {