Jupiter/Jupiter/Queue.cpp

/**
 * Copyright (C) 2013-2015 Jessica James.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Written by Jessica James <jessica.aj@outlook.com>
 */

#include "Queue.h"

struct Jupiter::Queue::Data
{
	Data *next;
	void *data;
};

Jupiter::Queue::Queue()
{
	Jupiter::Queue::end = new Jupiter::Queue::Data();
	Jupiter::Queue::end->next = nullptr;
	Jupiter::Queue::head = new Jupiter::Queue::Data();
	Jupiter::Queue::head->next = Jupiter::Queue::end;
	Jupiter::Queue::head->data = nullptr;
	Jupiter::Queue::length = 0;
}

Jupiter::Queue::~Queue()
{
	Jupiter::Queue::Data *p;
	Jupiter::Queue::Data *c = head;
	do
	{
		p = c;
		c = c->next;
		delete p;
	}
	while (c != nullptr);
}

void Jupiter::Queue::enqueue(void *data)
{
	Jupiter::Queue::Data *nEnd = new Jupiter::Queue::Data();
	nEnd->next = nullptr;
	end->data = data;
	end->next = nEnd;
	end = nEnd;
	Jupiter::Queue::length++;
}

void *Jupiter::Queue::dequeue()
{
	if (Jupiter::Queue::length > 0)
	{
		Jupiter::Queue::Data *tmp = Jupiter::Queue::head->next;
		Jupiter::Queue::head->next = tmp->next;
		void *data = tmp->data;
		delete tmp;
		Jupiter::Queue::length--;
		return data;
	}
	return nullptr;
}

size_t Jupiter::Queue::size() const
{
	return Jupiter::Queue::length;
}