vqueue.hp

早期freebsd实现

// This may look like C code, but it is really -*- C++ -*-
/* 
Copyright (C) 1988 Free Software Foundation
    written by Doug Lea ([e-mail])

This file is part of the GNU C++ Library.  This library is free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.  This library 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 Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/


#ifndef _<T>VQueue_h
#ifdef __GNUG__
#pragma interface
#endif
#define _<T>VQueue_h 1

#include "<T>.Queue.h"

class <T>VQueue : public <T>Queue
{
protected:
  int                   size;
  int                   cnt;
  int                   inp;
  int                   outp;
  <T>*                  s;

public:

                        <T>VQueue(int sz = DEFAULT_INITIAL_CAPACITY);
                        <T>VQueue(<T>VQueue&);
                        ~<T>VQueue();

  void                  operator = (<T>VQueue&);

  void                  enq(<T&> item);
  <T>                   deq();
  <T>&                  front();
  void                  del_front();

  int                   length();
  int                   empty();
  int                   full();

  int                   capacity();
  void                  resize(int sz);
  void                  clear();

  int                   OK();
};


inline <T>VQueue::<T>VQueue(int sz)
{
  s = new <T> [size = sz];
  cnt = inp = outp = 0;
}

inline <T>VQueue::~<T>VQueue()
{
  delete [] s;
}

inline void <T>VQueue::clear()
{
  inp = outp = 0;
  cnt = 0;
}

inline int <T>VQueue::empty()
{
  return cnt <= 0;
}

inline int <T>VQueue::capacity()
{
  return size;
}

inline int <T>VQueue::full()
{
  return cnt >= size;
}

inline int <T>VQueue::length()
{
  return cnt;
}

inline void <T>VQueue::enq(<T&> item)
{
  if (cnt >= size) error("enq to full Queue.");
  ++cnt;
  s[inp] = item;
  if (++inp == size) inp = 0;
}

inline <T> <T>VQueue::deq()
{
  if (cnt <= 0) error("deq from empty Queue.");
  --cnt;
  int i = outp;
  if (++outp == size) outp = 0;
  return s[i];
}


inline void <T>VQueue::del_front()
{
  if (cnt <= 0) error("delete from empty Queue.");
  --cnt;
  if (++outp == size) outp = 0;
}

inline <T>& <T>VQueue::front()
{
  if (empty()) error("top from empty Queue.");
  return s[outp];
}

#endif