openmohaa/code/qcommon/queue.h

/*
===========================================================================
Copyright (C) 2015 the OpenMoHAA team

This file is part of OpenMoHAA source code.

OpenMoHAA source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

OpenMoHAA source code 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with OpenMoHAA source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/

// queue.h: Generic Queue object
//

#ifndef __QUEUE_H__
#define __QUEUE_H__

#include "class.h"

template<class T>
class QueueNode : public Class
{
public:
	T data;
	QueueNode *next;

	QueueNode();
};

template<class T>
QueueNode<T>::QueueNode()
{
	data = NULL;
	next = NULL;
}

template<class T>
class Queue : public Class
{
private:
	QueueNode<T> *head;
	QueueNode<T> *tail;

public:
	Queue();
	~Queue();
	void Clear(void);
	qboolean Empty(void);
	void Enqueue(T data);
	T Dequeue(void);
	void Remove(T data);
	qboolean Inqueue(T data);
};

template<class T>
qboolean Queue<T>::Empty
	(
	void
	)
{
	if (head == NULL)
	{
		assert(!tail);
		return true;
	}

	assert(tail);
	return false;
}

template<class T>
void Queue<T>::Enqueue
	(
	T data
	)
{
	QueueNode<T> *tmp;

	tmp = new QueueNode<T>;
	assert(tmp);

	tmp->data = data;

	assert(!tmp->next);
	if (!head)
	{
		assert(!tail);
		head = tmp;
	}
	else
	{
		assert(tail);
		tail->next = tmp;
	}
	tail = tmp;
}

template<class T>
T Queue<T>::Dequeue
	(
	void
	)
{
	T ptr;
	QueueNode<T> *node;

	if (!head)
	{
		assert(!tail);
		return NULL;
	}

	node = head;
	ptr = node->data;

	head = node->next;
	if (head == NULL)
	{
		assert(tail == node);
		tail = NULL;
	}

	delete node;

	return ptr;
}

template<class T>
void Queue<T>::Clear
	(
	void
	)
{
	while (!Empty())
	{
		Dequeue();
	}
}

template<class T>
Queue<T>::Queue()
{
	head = NULL;
	tail = NULL;
}

template<class T>
Queue<T>::~Queue()
{
	Clear();
}

template<class T>
void Queue<T>::Remove
	(
	T data
	)
{
	QueueNode<T> *node;
	QueueNode<T> *prev;

	if (!head)
	{
		assert(!tail);

		gi.DPrintf("Queue::Remove : Data not found in queue\n");
		return;
	}

	for (prev = NULL, node = head; node != NULL; prev = node, node = node->next)
	{
		if (node->data == data)
		{
			break;
		}
	}

	if (!node)
	{
		gi.DPrintf("Queue::Remove : Data not found in queue\n");
	}
	else
	{
		if (!prev)
		{
			// at head
			assert(node == head);
			head = node->next;
			if (head == NULL)
			{
				assert(tail == node);
				tail = NULL;
			}
		}
		else
		{
			prev->next = node->next;
			if (prev->next == NULL)
			{
				// at tail
				assert(tail == node);
				tail = prev;
			}
		}

		delete node;
	}
}

template<class T>
qboolean Queue<T>::Inqueue
	(
	T data
	)
{
	QueueNode<T> *node;

	for (node = head; node != NULL; node = node->next)
	{
		if (node->data == data)
		{
			return true;
		}
	}

	return false;
}

#endif /* queue.h */