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%%	options

copyright owner =       Dirk Krause
copyright year  =       2013-xxxx
SPDX-License-Identifier:	BSD-3-Clause

%%	header

#ifndef	DK4CONF_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4conf.h"
#else
#include <dktools-4/dk4conf.h>
#endif
#endif

#ifndef	DK4ERROR_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4error.h"
#else
#include <dktools-4/dk4error.h>
#endif
#endif

#ifndef	DK4STO_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4sto.h"
#else
#include <dktools-4/dk4sto.h>
#endif
#endif

#include <stdexcept>
#include <new>

#ifndef	DK4COMPARABLE_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "Dk4Comparable.h"
#else
#include <dktools-4/Dk4Comparable.h>
#endif
#endif


/**	Namespace to protect Container and Iterator from name collisions.
*/
namespace DkTools4 {

	/**	Container class for sorted storage.
	*/
	template<class T> class Container;

	/**	Iterator class to traverse a Container.
	*/
	template<class T> class Iterator;

	/**	A container class for sorted storage.
		The objects saved in the storage must be derived from the Comparable
		class.
	*/
	template<class T>
	class Container
	{
		/**	Iterator is allowed to access Containers internals.
		*/
		friend class Iterator<T>;

		private:

			/**	Storage to store elements.
			*/
			dk4_sto_t		*sto;

			/**	Iterator, used in destructor.
			*/
			dk4_sto_it_t	*it;

			/**	Comparison criteria for ordering elements.
			*/
			int				cr;

			/**	Flag: Container is owner of the objects and in charge
				for destruction.
			*/
			bool			bOwner;

		public:

			/**	Constructor.
				@param	crit	Sort criteria for objects in container.
				@param	owner	Owner flag value. If a container is the owner
								of the objects stored in it, the objects are
								deleted in the containers destructor.
				Exceptions:
				- std::bad_alloc<br>
				  if there is not enough memory available.
			*/

			Container<T>(int crit, bool owner = false)
			/* throws(std::bad_alloc) */
			;


			/**	Destructor.
			*/

			~Container<T>();


			/**	Add an object to the container.
				@param	ptr		Pointer to add.
				@return	True on success, false on error (object not added).
			*/

			bool
			add(T *ptr);


			/**	Remove object from container.
				@param	ptr		Pointer to remove.
				@return	True on success, false on error (element not found).
			*/

			bool
			remove(T *ptr);


			/**	Check owner flag.
				@return	Owner flag value.
			*/

			bool
			isOwner(void) const;


			/**	Reset iterator.
			*/

			void
			reset(void);


			/**	Set iterator to exact position.
				@param	data	Object to search for.
				@param	crit	Comparison criteria.
				@return	Pointer to found object on success, NULL otherwise.
			*/

			T *
			findExact(void const *data, int crit);


			/**	Set iterator to object evaluating equally.
				@param	data	Object to search for.
				@param	crit	Comparison criteria.
				@return	Pointer to found object on success, NULL otherwise.
			*/

			T *
			findLike(void const *data, int crit);


			/**	Step to next element.
				@return	Pointer to next object (if there is one), NULL
				if there is no next object.
			*/

			T *
			next(void);

	};	/* End of class Container */



	/**	Iterator class to traverse a Container.
	*/
	template<class T>
	class Iterator
	{
		private:
			/**	Low-level iterator.
			*/
			dk4_sto_it_t	*it;

		public:

			/**	Constructor.
				@param	cont	Container for which the iterator is for.

				Exceptions:
				- std::bad_alloc<br>
				  if there is not enough memory available.
			*/

			Iterator<T>(Container<T> & cont)
			/* throws(std::bad_alloc) */
			;


			/**	Destructor.
			*/

			~Iterator<T>();


			/**	Reset iterator.
			*/

			void
			reset(void);


			/**	Set iterator to exact position.
				@param	data	Object to search for.
				@param	crit	Comparison criteria.
				@return	Pointer to found object on success, NULL otherwise.
			*/

			T *
			findExact(void const *data, int crit);


			/**	Set iterator to object evaluating equally.
				@param	data	Object to search for.
				@param	crit	Comparison criteria.
				@return	Pointer to found object on success, NULL otherwise.
			*/

			T *
			findLike(void const *data, int crit);


			/**	Step to next element.
				@return	Pointe to next object (if there is one), NULL
				if there is no next object.
			*/

			T *
			next(void);

	};	/* End of class Iterator */

}	/* End of namespace DkTools4 */



$*
	Implementation for container methods.
$*

template<class T>
DkTools4::Container<T>::Container(int crit, bool owner)
{
	bool	mustThrow = true;		/* Flag: Must throw exception. */

	/*	Initialize members.
	*/
	bOwner	= owner;
	cr		= crit;
	sto		= NULL;
	it		= NULL;

	/*	Allocate memory.
	*/
	sto = dk4sto_open(NULL);
	if(NULL != sto) {
		dk4sto_set_comp(sto, DkTools4::Comparable::compareTwoPointers, crit);
		it = dk4sto_it_open(sto, NULL);
		if (NULL != it) {
			mustThrow = false;	/* All memory allocations succeeded. */
		}
		else {
			dk4sto_close(sto);
			sto = NULL;
		}
	}
	if (mustThrow) {
		throw(std::bad_alloc());
	}
}



/*	The destructor is also called when an exception is thrown by
	the constructor. So we must check the sto and it component for
	being not NULL.
*/

template<class T>
DkTools4::Container<T>::~Container<T>()
{
	T *ptr;

	/*	Close storage and iterator.
		If we are the owner of the objects stored, delete the objects too.
	*/
	if (NULL != it) {
		if (bOwner) {
			dk4sto_it_reset(it);
			while(NULL != (ptr = (T *)dk4sto_it_next(it))) {
				delete ptr;
			}
		}
		dk4sto_it_close(it);
	}
	if (NULL != sto) {
		dk4sto_close(sto);
	}

	/*	Mark all components as not allocated.
	*/
	sto = NULL;
	it  = NULL;
	cr  = 0;
	bOwner = false;
}



/*	The remaining container methods are not called if there was
	an exception from the constructor. So no NULL pointer checks
	are necessary here.
*/


template<class T>
bool
DkTools4::Container<T>::add(T *ptr)
{
	bool back = false;

	if(0 != dk4sto_add(sto, (void *)ptr, NULL)) {
		back = true;
	}
	return back;
}



template<class T>
bool
DkTools4::Container<T>::remove(T *ptr)
{
	bool back = false;

	if(0 != dk4sto_remove(sto, (void *)ptr, NULL)) {
		back = true;
	}
	return back;
}



template<class T>
bool
DkTools4::Container<T>::isOwner(void) const
{
	return bOwner;
}



/*	The remaining iterator methods are not invoked if the constructor
	throws an exception, so we do not need to check the it component.
*/

template<class T>
void
DkTools4::Container<T>::reset(void)
{
	dk4sto_it_reset(it);
}



template<class T>
T *
DkTools4::Container<T>::findExact(void const *data, int crit)
{
	T *back = NULL;

	back = (T *)dk4sto_it_find_exact(it, data);
	return back;
}



template<class T>
T *
DkTools4::Container<T>::findLike(void const *data, int crit)
{
	T *back;

	back = (T *)dk4sto_it_find_like(it, data, crit);
	return back;
}



template<class T>
T *
DkTools4::Container<T>::next(void)
{
	T *back = NULL;

	back = (T *)dk4sto_it_next(it);
	return back;
}



$*
	Implementation for iterator methods.
$*

template<class T>
DkTools4::Iterator<T>::Iterator(Container<T> & cont)
{
	it = dk4sto_it_open(cont.sto, NULL);
	if(NULL != it) {
		dk4sto_it_reset(it);
	}
	else {
		throw(std::bad_alloc());
	}
}



/*	The iterators destructor is also invoked if the constructor throws
	an exception. So we must check the it component to be not NULL.
*/

template<class T>
DkTools4::Iterator<T>::~Iterator<T>()
{
	if (NULL != it) {
		dk4sto_it_close(it); it = NULL;
	}
}



/*	The remaining iterator methods are not invoked if the constructor
	throws an exception, so we do not need to check the it component.
*/

template<class T>
void
DkTools4::Iterator<T>::reset(void)
{
	dk4sto_it_reset(it);
}



template<class T>
T *
DkTools4::Iterator<T>::findExact(void const *data, int crit)
{
	T *back = NULL;
	back = (T *)dk4sto_it_find_exact(it, data);
	return back;
}



template<class T>
T *
DkTools4::Iterator<T>::findLike(void const *data, int crit)
{
	T *back;
	back = (T *)dk4sto_it_find_like(it, data, crit);
	return back;
}



template<class T>
T *
DkTools4::Iterator<T>::next(void)
{
	T *back = NULL;
	back = (T *)dk4sto_it_next(it);
	return back;
}



/* vim: set ai sw=4 ts=4 : */