Array_Base.h

Go to the documentation of this file.

// -*- C++ -*-

//=============================================================================
/**
 *  @file Array_Base.h
 *
 *  $Id: Array_Base.h 80826 2008-03-04 14:51:23Z wotte $
 *
 *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
 */
//=============================================================================

#ifndef ACE_ARRAY_BASE_H
#define ACE_ARRAY_BASE_H

#include /**/ "ace/pre.h"

#include /**/ "ace/config-all.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#include "ace/Global_Macros.h"
#include "ace/Malloc_Base.h"
#include <iterator>  /* For reverse_iterator adapters */

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

// Forward declaration.
template <class T> class ACE_Array_Iterator;

/**
 * @class ACE_Array_Base
 *
 * @brief Implement a simple dynamic array
 *
 * This parametric class implements a simple dynamic array;
 * resizing must be controlled by the user. No comparison or find
 * operations are implemented.
 */
template<class T>
class ACE_Array_Base
{
public:

  // Old/ACE-style traits.
  typedef T TYPE;
  typedef ACE_Array_Iterator<T> ITERATOR;

  // STL-style typedefs/traits.
  typedef T                              value_type;
  typedef value_type *                   iterator;
  typedef value_type const *             const_iterator;
  typedef value_type &                   reference;
  typedef value_type const &             const_reference;
  typedef value_type *                   pointer;
  typedef value_type const *             const_pointer;
  typedef ptrdiff_t                      difference_type;
  typedef ACE_Allocator::size_type       size_type;

  ACE_DECLARE_STL_REVERSE_ITERATORS

  // = Initialization and termination methods.

  /// Dynamically create an uninitialized array.
  ACE_Array_Base (size_type size = 0,
                  ACE_Allocator * the_allocator = 0);

  /// Dynamically initialize the entire array to the <default_value>.
  ACE_Array_Base (size_type size,
                  T const & default_value,
                  ACE_Allocator * the_allocator = 0);

  /**
   * The copy constructor performs initialization by making an exact
   * copy of the contents of parameter <s>, i.e., *this == s will
   * return true.
   */
  ACE_Array_Base (ACE_Array_Base<T> const & s);

  /**
   * Assignment operator performs an assignment by making an exact
   * copy of the contents of parameter <s>, i.e., *this == s will
   * return true.  Note that if the <max_size_> of <array_> is >= than
   * <s.max_size_> we can copy it without reallocating.  However, if
   * <max_size_> is < <s.max_size_> we must delete the <array_>,
   * reallocate a new <array_>, and then copy the contents of <s>.
   */
  void operator= (ACE_Array_Base<T> const & s);

  /// Clean up the array (e.g., delete dynamically allocated memory).
  ~ACE_Array_Base (void);

  // = Set/get methods.

  /// Set item in the array at location @a slot.  Doesn't
  /// perform range checking.
  T & operator[] (size_type slot);

  /// Get item in the array at location @a slot.  Doesn't
  /// perform range checking.
  T const & operator[] (size_type slot) const;

  /// Set an item in the array at location @a slot.  Returns
  /// -1 if @a slot is not in range, else returns 0.
  int set (T const & new_item, size_type slot);

  /**
   * Get an item in the array at location @a slot.  Returns -1 if
   * @a slot is not in range, else returns 0.  Note that this function
   * copies the item.  If you want to avoid the copy, you can use
   * the const operator [], but then you'll be responsible for range checking.
   */
  int get (T & item, size_type slot) const;

  /// Returns the <cur_size_> of the array.
  size_type size (void) const;

  /**
   * Changes the size of the array to match <new_size>.
   * It copies the old contents into the new array.
   * Return -1 on failure.
   */
  int size (size_type new_size);

  /// Returns the <max_size_> of the array.
  size_type max_size (void) const;

  /**
   * Changes the size of the array to match <new_size>.
   * It copies the old contents into the new array.
   * Return -1 on failure.
   * It does not affect new_size
   */
  int max_size (size_type new_size);

  /**
   * @name Forward Iterator Accessors
   *
   * Forward iterator accessors.
   */
  //@{
  iterator begin (void);
  iterator end   (void);
  const_iterator begin (void) const;
  const_iterator end   (void) const;
  //@}

  /**
   * @name Reverse Iterator Accessors
   *
   * Reverse iterator accessors.
   */
  //@{
  reverse_iterator rbegin (void);
  reverse_iterator rend   (void);
  const_reverse_iterator rbegin (void) const;
  const_reverse_iterator rend   (void) const;
  //@}

  /// Swap the contents of this array with the given @a array in
  /// an exception-safe manner.
  void swap (ACE_Array_Base<T> & array);

protected:

  /// Returns 1 if @a slot is within range, i.e., 0 >= @a slot <
  /// <cur_size_>, else returns 0.
  bool in_range (size_type slot) const;

  /// Maximum size of the array, i.e., the total number of <T> elements
  /// in <array_>.
  size_type max_size_;

  /**
   * Current size of the array.  This starts out being == to
   * <max_size_>.  However, if we are assigned a smaller array, then
   * <cur_size_> will become less than <max_size_>.  The purpose of
   * keeping track of both sizes is to avoid reallocating memory if we
   * don't have to.
   */
  size_type cur_size_;

  /// Pointer to the array's storage buffer.
  value_type * array_;

  /// Allocation strategy of the ACE_Array_Base.
  ACE_Allocator * allocator_;

  friend class ACE_Array_Iterator<T>;
};

// ****************************************************************

/**
 * @class ACE_Array_Iterator
 *
 * @brief Implement an iterator over an ACE_Array.
 *
 * This iterator is safe in the face of array element deletions.
 * But it is NOT safe if the array is resized (via the ACE_Array
 * assignment operator) during iteration.  That would be very
 * odd, and dangerous.
 */
template <class T>
class ACE_Array_Iterator
{
public:
  // = Initialization method.
  ACE_Array_Iterator (ACE_Array_Base<T> &);

  // = Iteration methods.

  /// Pass back the <next_item> that hasn't been seen in the Array.
  /// Returns 0 when all items have been seen, else 1.
  int next (T *&next_item);

  /// Move forward by one element in the Array.  Returns 0 when all the
  /// items in the Array have been seen, else 1.
  int advance (void);

  /// Returns 1 when all items have been seen, else 0.
  int done (void) const;

  /// Dump the state of an object.
  void dump (void) const;

  /// Declare the dynamic allocation hooks.
  ACE_ALLOC_HOOK_DECLARE;

private:
  /// Pointer to the current item in the iteration.
  size_t current_;

  /// Pointer to the Array we're iterating over.
  ACE_Array_Base<T> &array_;
};

ACE_END_VERSIONED_NAMESPACE_DECL

#if defined (__ACE_INLINE__)
#include "ace/Array_Base.inl"
#endif /* __ACE_INLINE__ */

#if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
#include "ace/Array_Base.cpp"
#endif /* ACE_TEMPLATES_REQUIRE_SOURCE */

#if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
#pragma implementation ("Array_Base.cpp")
#endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */

#include /**/ "ace/post.h"

#endif /* ACE_ARRAY_BASE_H */

---