tpl_arrayQueue.H

/*
  This file is part of Aleph system

  Copyright (c) 2002, 2003, 2004, 2005, 2006
  UNIVERSITY LOS ANDES (ULA) Merida - REPÚBLICA BOLIVARIANA DE VENEZUELA  

  - Center of Studies in Microelectronics & Distributed Systems (CEMISID) 
  - ULA Computer Science Department
  - FUNDACITE Mérida - Ministerio de Ciencia y Tecnología

  PERMISSION TO USE, COPY, MODIFY AND DISTRIBUTE THIS SOFTWARE AND ITS
  DOCUMENTATION IS HEREBY GRANTED, PROVIDED THAT BOTH THE COPYRIGHT
  NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES OF THE
  SOFTWARE, DERIVATIVE WORKS OR MODIFIED VERSIONS, AND ANY PORTIONS
  THEREOF, AND THAT BOTH NOTICES APPEAR IN SUPPORTING DOCUMENTATION.

  Aleph 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.

  UNIVERSIDAD DE LOS ANDES requests users of this software to return to 

  Leandro Leon
  CEMISID 
  Ed La Hechicera 
  3er piso, ala sur
  Facultad de Ingenieria 
  Universidad de Los Andes 
  Merida - REPÚBLICA BOLIVARIANA DE VENEZUELA    or

  lrleon@ula.ve

  any improvements or extensions that they make and grant Universidad 
  de Los Andes (ULA) the rights to redistribute these changes. 

  Aleph is (or was) granted by: 
  - Consejo de Desarrollo Cientifico, Humanistico, Tecnico de la ULA 
    (CDCHT)
  - Fundacite Mérida
*/


# ifndef TPL_ARRAYQUEUE_H
# define TPL_ARRAYQUEUE_H

# include <ahAssert.H>
# include <ahDefs.H>

using namespace Aleph;

namespace Aleph {

    template <typename T> 
class ArrayQueue
{

private:

  const size_t two_pow;

  const size_t dim;

  T * array;
  size_t front_index; /* index of oldest inserted item */
  size_t rear_index;
  const size_t mask;
  size_t num_items; 

  void increase_index(size_t & i, const size_t & inc = 1) const
  {

    I( ((i + inc)%dim) == ((i+ inc)&mask) );

    i += inc;
    i &= mask;  
  }
  T & rear_item(const size_t & i = 0) 
  {

    I(static_cast<size_t>((rear_index - i - 1) & mask) == 
           (rear_index - i - 1)%dim);

    return array[static_cast<size_t> ((rear_index - i - 1) & mask)];
  }

public:


  ArrayQueue(const size_t & tp = 8) 
    : two_pow(tp), dim(1<<two_pow), array(NULL), front_index(0), 
      rear_index(0), mask(dim - 1), num_items(0)
  {
    array = new T [dim];
  }

  ~ArrayQueue()
  {
    if (array != NULL)
      delete [] array;
  }

  T & put(const T & item) throw(std::exception,std::overflow_error)
  {

    if (num_items >= dim)
      throw std::overflow_error ("Array queue is full");

    array[rear_index] = item;
    T & ret_val = array[rear_index];
    increase_index(rear_index);
    num_items++;
    return ret_val;
  }
  T & putn(const size_t & n) throw(std::exception, std::overflow_error)
  {

    if (num_items + n >= dim)
      throw std::overflow_error ("Array queue is full");

    increase_index(rear_index, n);
    num_items += n;

    return rear_item();
  }
  T get() throw(std::exception, std::underflow_error)
  {

    if (num_items == 0)
      throw std::underflow_error ("queue is empty");

    num_items--;
    T ret_val = array[front_index]; 
    increase_index(front_index);

    return ret_val;
  }
  T & getn(const size_t & n) throw(std::exception, std::underflow_error)
  {

    if (num_items < n)
      throw std::underflow_error ("queue is empty");

    num_items -= n;
    increase_index(front_index, n);
    return array[front_index];
  } 
  T & front(const size_t & i = 0) throw(std::exception, std::underflow_error)
  {
    if (i >= num_items) 
      throw std::underflow_error ("queue is empty");
    return array[front_index + i];
  }
  T & rear(const size_t & i = 0) throw(std::exception, std::underflow_error)
  {
    if (i >= num_items) 
      throw std::underflow_error ("queue is empty");
    return rear_item(i);
  }

  const size_t & size() const { return num_items; }

  bool is_empty() const { return num_items == 0; }

  const size_t & capacity() const { return dim; }
};

    template <typename T> 
class FixedQueue
{

private:

  const size_t two_pow;

  const size_t dim;

  T * array;
  size_t front_index; /* index of oldest inserted item */
  size_t rear_index;
  const size_t mask;
  size_t num_items; 
  void increase_index(size_t & i, const size_t & inc = 1) const
  {

    I( ((i + inc)%dim) == ((i+ inc)&mask) );

    i += inc;
    i &= mask;  
  }
  T & rear_item(const size_t & i = 0) 
  {

    I(static_cast<size_t>((rear_index - i - 1) & mask) == 
           (rear_index - i - 1)%dim);

    return array[static_cast<size_t> ((rear_index - i - 1) & mask)];
  }

public:

  FixedQueue(const size_t & tp = 8)  
    : two_pow(tp), dim(1<<two_pow), array(NULL), front_index(0), 
      rear_index(0), mask(dim - 1), num_items(0)
  { 
    array = new T [dim];
  }

  ~FixedQueue()
  {
    if (array != NULL)
      delete [] array;
  }

  T & put(const T& item) throw(std::exception, std::overflow_error)
  {
    I(num_items < dim);
    array[rear_index] = item;
    T & ret_val = array[rear_index];
    increase_index(rear_index);
    num_items++;
    return ret_val;
  }

  T & putn(const size_t & n) throw(std::exception, std::overflow_error)
  {
    I(num_items + n < dim);
    increase_index(rear_index, n);
    num_items += n;

    return rear_item();
  }

  T get() throw(std::exception, std::underflow_error)
  {
    I(num_items > 0);
    num_items--;
    T ret_val = array[front_index]; 
    increase_index(front_index);

    return ret_val;
  }

  T & getn(const size_t & n) throw(std::exception, std::underflow_error)
  {
    I(num_items >= n);
    num_items -= n;
    increase_index(front_index, n);
    return array[front_index];
  } 

  T & front(const size_t & i = 0) throw(std::exception, std::underflow_error)
  {
    I(i < num_items);
    return array[front_index + i];
  }

  T & rear(const size_t & i = 0) throw(std::exception, std::underflow_error)
  {
    I(i < num_items);
    return rear_item(i);
  }
  const size_t & size() const { return num_items; }

  bool is_empty() const { return num_items == 0; }

  const size_t & capacity() const { return dim; }
};

} // end namespace Aleph

# endif /* TPL_ARRAYQUEUE_H */

---