// Queue.cpp: implementation of the CQueue class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "CVoiceChat.h"
#include "Queue.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CQueue::CQueue()
{
	front=NULL;
	back=NULL;
	count=0;
	InitializeCriticalSection(&CriticalSection);
	//m_event4=CreateEvent(NULL,false,true,NULL);
}
bool CQueue::InsertItem(CQueueItem *item)
{
	::EnterCriticalSection(&CriticalSection);
	if(front==NULL)
	{
		front=back=item;
		count++;
	}
	else
	{
		back->nextItem=item;
		back=item;
		count++;
		
	}
	::LeaveCriticalSection(&CriticalSection);
	return true;
}
//取出數據后應將內存釋放
char* CQueue::TakeOutItem()
{
    CQueueItem *item;
	::EnterCriticalSection(&CriticalSection);
	if(front==NULL)
	{
		::LeaveCriticalSection(&CriticalSection);
		AfxMessageBox("緩沖區中沒有數據可取!");
		return NULL;
	}
	if(front==back)
	{
		item=front;
		front=back=NULL;
		count--;
		::LeaveCriticalSection(&CriticalSection);
		return item->data;
	}
	item=front;
	front=front->nextItem;
	count--;
	::LeaveCriticalSection(&CriticalSection);
	return item->data;

}
int CQueue::Itemnum()
{
	::EnterCriticalSection(&CriticalSection);
	int ncount=count;
	::LeaveCriticalSection(&CriticalSection);
	return ncount;
}
bool CQueue::deleteall()
{
	CQueueItem *item;
	EnterCriticalSection(&CriticalSection);
	while(1)
	{
		if(front==NULL)
		{
			LeaveCriticalSection(&CriticalSection);
			return 1;
		}
		if(front==back)
		{
			item=front;
			delete(item);
			front=back=NULL;
			count=0;
			LeaveCriticalSection(&CriticalSection);
			return 1;
		}
		else
		{
			item=front;
			front=front->nextItem;
			delete(item);
		}
	}
	//::LeaveCriticalSection(&CriticalSection);
	return 1;
}
CQueue::~CQueue()
{
	CQueueItem *pcur;
	while(front!=NULL)
	{
		pcur=front;
		front=front->nextItem;
		delete(pcur);
	}
}