#include "GCycleQueue.h"
#include <math.h>
#include <memory.h>
#include <stdio.h>

GCycleQueue::GCycleQueue()
{
    m_ptrFrameQueue = nullptr;

	m_nFront = 0;
    m_nTail = 0;
	m_nQueueSize = 10;
}


GCycleQueue::~GCycleQueue()
{
	DestroyQueue();
}

/*
 *初始化队列
 */
bool	GCycleQueue::InitQueue(int nQueueSize)
{
	DestroyQueue();

    //QMutexLocker lock(&m_mutex);
	m_mutex.lock();


	m_nQueueSize = (nQueueSize > 0) ? (nQueueSize + 1) : (DEFAULT_QUEUE_SIZE + 1);		//循环队列，有一个数据块为空，用于存储队列指针


    m_ptrFrameQueue = new unsigned char[m_nQueueSize][MAX_FRAME_SIZE];
	
    if(nullptr == m_ptrFrameQueue)
	{

		return false;
	}
	m_mutex.unlock();

	return true;
}

/*
 *数据插入队列尾部
 */
bool	GCycleQueue::PushBack(Frame* pFrameData,int& nRes)
{
	//if (m_nFrameSize != nFrameSize)
	//{
	//	return false;
 //   }

    if(nullptr == pFrameData)
    {
        return false;
    }

    //QMutexLocker lock(&m_mutex);
	m_mutex.lock();

    nRes = 0;

	//如果队尾与队首相同，说明队列已满，队首指针后移一位
	if ((m_nTail + 1) % m_nQueueSize == m_nFront)
	{
		m_nFront++;
		m_nFront %= m_nQueueSize;
        nRes = 1;
	}

	//数据入队
    memcpy(m_ptrFrameQueue[m_nTail], pFrameData, sizeof(Frame));

	m_nTail++;
	m_nTail %= m_nQueueSize;

	m_mutex.unlock();

	return true;
}

/*
 *从队列头部获取数据
 */
bool	GCycleQueue::GetFront(Frame* pFrameData)
{
	if (IsEmpty() )
	{
		return false;
    }

    //QMutexLocker lock(&m_mutex);
	m_mutex.lock();

    memcpy(pFrameData, m_ptrFrameQueue[m_nFront], sizeof(Frame));

	m_nFront++;
	m_nFront %= m_nQueueSize;
	m_mutex.unlock();
	return true;
}

/*
 *判断队列是否为空
 */
bool	GCycleQueue::IsEmpty()
{
	return !(Size() > 0);
}

/*
 *清空队列
 */
void	GCycleQueue::Clear()
{
    //QMutexLocker lock(&m_mutex);
	m_mutex.lock();
	m_nFront = 0;
	m_nTail = 0;
	m_mutex.unlock();
}

/*
 *获取队列大小(有效数据个数)
 */
int		GCycleQueue::Size()
{
	int nSize = 0;

    // QMutexLocker lock(&m_mutex);
	 m_mutex.lock();

	if (m_nTail > m_nFront)
	{
		nSize = m_nTail - m_nFront;
	}
	else if (m_nTail < m_nFront)
	{
		nSize = m_nQueueSize + m_nTail - m_nFront;
	}
	else
	{
		nSize = 0;
	}
	m_mutex.unlock();
	return nSize;
}

/*
 *销毁队列
 */
void	GCycleQueue::DestroyQueue()
{
    //QMutexLocker lock(&m_mutex);

	m_mutex.lock();

    if (nullptr != m_ptrFrameQueue)
	{
		delete [] m_ptrFrameQueue;
        m_ptrFrameQueue = nullptr;
	}

	m_nFront = 0;
	m_nTail = 0;
	m_mutex.unlock();
}