Click here to Skip to main content
Click here to Skip to main content
Add your own
alternative version

The Windows Access Control Model: Part 2

, 27 Jun 2005
This second part of the Access Control series will program with the basic Access Control structures.
boost.zip
boost
config
compiler
platform
stdlib
detail
mpl
aux_
config
preprocessed
bcc
bcc551
gcc
msvc60
msvc70
mwcw
no_ctps
no_ttp
plain
preprocessor
range_c
preprocessor
arithmetic
detail
array
comparison
config
control
detail
edg
msvc
detail
facilities
iteration
detail
bounds
iter
list
detail
edg
logical
punctuation
repetition
detail
edg
msvc
selection
seq
detail
slot
detail
tuple
regex
v3
test
detail
included
type_traits
detail
utility
userfun.zip
ATL
release
UserFun.exe
LowLevel
release
LowLevel.exe
2000
release
2000.exe
whoami.zip
Whoami
release
Whoami.exe
/*
 *
 * Copyright (c) 1998-2002
 * Dr John Maddock
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Dr John Maddock makes no representations
 * about the suitability of this software for any purpose.  
 * It is provided "as is" without express or implied warranty.
 *
 */

 /*
  *   LOCATION:    see http://www.boost.org for most recent version.
  *   FILE         regex_stack.hpp
  *   VERSION      see <boost/version.hpp>
  *   DESCRIPTION: Implements customised internal regex stacks.
  *                Note this is an internal header file included
  *                by regex.hpp, do not include on its own.
  */

#ifndef BOOST_REGEX_STACK_HPP
#define BOOST_REGEX_STACK_HPP

#ifndef BOOST_REGEX_CONFIG_HPP
#include <boost/regex/config.hpp>
#endif
#ifndef BOOST_REGEX_RAW_BUFFER_HPP
#include <boost/regex/v3/regex_raw_buffer.hpp>
#endif

namespace boost{
   namespace re_detail{

#ifdef __BORLANDC__
   #pragma option push -a8 -b -Vx -Ve -pc
#endif

//
// class jstack
// simplified stack optimised for push/peek/pop
// operations, we could use std::stack<std::vector<T>> instead...
//
template <class T, class Allocator = BOOST_DEFAULT_ALLOCATOR(T) >
class jstack
{
private:
   typedef typename boost::detail::rebind_allocator<unsigned char, Allocator>::type allocator_type;
   typedef typename boost::detail::rebind_allocator<T, Allocator>::type             T_alloc_type;
   typedef typename T_alloc_type::size_type                              size_type;
   typedef T value_type;
   struct node
   {
      node* next;
      T* start;  // first item
      T* end;    // last item
      T* last;   // end of storage
   };
   
   //
   // empty base member optimisation:
   struct data : public allocator_type
   {
      padding buf[(sizeof(T) * 16 + sizeof(padding) - 1) / sizeof(padding)];
      data(const Allocator& a) : allocator_type(a){}
   };

   data alloc_inst;
   mutable node* m_stack;
   mutable node* unused;
   node base;
   size_type block_size;

   void BOOST_REGEX_CALL pop_aux()const;
   void BOOST_REGEX_CALL push_aux();

public:
   jstack(size_type n = 64, const Allocator& a = Allocator());

   ~jstack();

   node* BOOST_REGEX_CALL get_node()
   {
      node* new_stack = reinterpret_cast<node*>(alloc_inst.allocate(sizeof(node) + sizeof(T) * block_size));
      BOOST_REGEX_NOEH_ASSERT(new_stack)
      new_stack->last = reinterpret_cast<T*>(new_stack+1);
      new_stack->start = new_stack->end = new_stack->last + block_size;
      new_stack->next = 0;
      return new_stack;
   }

   bool BOOST_REGEX_CALL empty()
   {
      return (m_stack->start == m_stack->end) && (m_stack->next == 0);
   }

   bool BOOST_REGEX_CALL good()
   {
      return (m_stack->start != m_stack->end) || (m_stack->next != 0);
   }

   T& BOOST_REGEX_CALL peek()
   {
      if(m_stack->start == m_stack->end)
         pop_aux();
      return *m_stack->end;
   }

   const T& BOOST_REGEX_CALL peek()const
   {
      if(m_stack->start == m_stack->end)
         pop_aux();
      return *m_stack->end;
   }

   void BOOST_REGEX_CALL pop()
   {
      if(m_stack->start == m_stack->end)
         pop_aux();
      ::boost::re_detail::pointer_destroy(m_stack->end);
      ++(m_stack->end);
   }

   void BOOST_REGEX_CALL pop(T& t)
   {
      if(m_stack->start == m_stack->end)
         pop_aux();
      t = *m_stack->end;
      ::boost::re_detail::pointer_destroy(m_stack->end);
      ++(m_stack->end);
   }

   void BOOST_REGEX_CALL push(const T& t)
   {
      if(m_stack->end == m_stack->last)
         push_aux();
      --(m_stack->end);
      pointer_construct(m_stack->end, t);
   }

};

template <class T, class Allocator>
jstack<T, Allocator>::jstack(size_type n, const Allocator& a)
    : alloc_inst(a)
{
  unused = 0;
  block_size = n;
  m_stack = &base;
  base.last = reinterpret_cast<T*>(alloc_inst.buf);
  base.end = base.start = base.last + 16;
  base.next = 0;
}

template <class T, class Allocator>
void BOOST_REGEX_CALL jstack<T, Allocator>::push_aux()
{
   // make sure we have spare space on TOS:
   register node* new_node;
   if(unused)
   {
      new_node = unused;
      unused = new_node->next;
      new_node->next = m_stack;
      m_stack = new_node;
   }
   else
   {
      new_node = get_node();
      new_node->next = m_stack;
      m_stack = new_node;
   }
}

template <class T, class Allocator>
void BOOST_REGEX_CALL jstack<T, Allocator>::pop_aux()const
{
   // make sure that we have a valid item
   // on TOS:
   jm_assert(m_stack->next);
   register node* p = m_stack;
   m_stack = p->next;
   p->next = unused;
   unused = p;
}

template <class T, class Allocator>
jstack<T, Allocator>::~jstack()
{
   node* condemned;
   while(good())
      pop();
   while(unused)
   {
      condemned = unused;
      unused = unused->next;
      alloc_inst.deallocate(reinterpret_cast<unsigned char*>(condemned), sizeof(node) + sizeof(T) * block_size);
   }
   while(m_stack != &base)
   {
      condemned = m_stack;
      m_stack = m_stack->next;
      alloc_inst.deallocate(reinterpret_cast<unsigned char*>(condemned), sizeof(node) + sizeof(T) * block_size);
   }
}

#ifdef __BORLANDC__
  #pragma option pop
#endif

} // namespace re_detail
} // namespace boost

#endif










By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

oshah
Web Developer
United States United States
Mr. Shah is a reclusive C++/C# developer lurking somewhere in the depths of the city of London. He learnt physics at Kings' College London and obtained a Master in Science there. Having earned an MCAD, he teeters on the brink of transitioning from C++ to C#, unsure of which language to jump to. Fortunately, he also knows how to use .NET interop to merge code between the two languages (which means he won't have to make the choice anytime soon).
 
His interests (apart from programming) are walking, football (the real one!), philosophy, history, retro-gaming, strategy gaming, and any good game in general.
 
He maintains a website / blog / FAQ / junk at shexec32.serveftp.net, where he places the best answers he's written to the questions you've asked. If you can find him, maybe you can hire Mr. Shah to help you with anything C++[/CLI]/C#/.NET related Smile | :) .

| Advertise | Privacy | Mobile
Web04 | 2.8.140827.1 | Last Updated 27 Jun 2005
Article Copyright 2005 by oshah
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid