#include "stdafx.h"
#include "BuffManager.h"

BuffNode::BuffNode()
{
	m_Buff.resize(PAGE, 0);
}

BuffNode::~BuffNode()
{

}


//--------------
BuffManager::BuffManager()
{
	BuffNode *p = NULL;

	m_Lock = CreateMutex(0, 0, 0);
	WaitForSingleObject(m_Lock, INFINITE);

	//for the first time ,init as four
	p = new BuffNode();
	m_BuffManager.push_back(p);
	p = new BuffNode();
	m_BuffManager.push_back(p);
	p = new BuffNode();
	m_BuffManager.push_back(p);
	p = new BuffNode();
	m_BuffManager.push_back(p);

	ReleaseMutex(m_Lock);

}


BuffManager::~BuffManager()
{
	WaitForSingleObject(m_Lock, INFINITE);
	for (size_t i = 0; i < m_BuffManager.size(); i++)
	{
		delete m_BuffManager[i];
	}
	m_BuffManager.clear();

	ReleaseMutex(m_Lock);

	CloseHandle(m_Lock);



}

BuffNode *BuffManager::GetBuff()
{
	BuffNode *p = NULL;
	WaitForSingleObject(m_Lock, INFINITE);

	if (m_BuffManager.size() > 0)
	{
		p = m_BuffManager[m_BuffManager.size() - 1];
		m_BuffManager.pop_back();
		p->m_Buff[0] = 0;
	}
	else
	{
		//we need new one
		p = new BuffNode();
		p->m_Buff[0] = 0;

	}

	ReleaseMutex(m_Lock);

	return p;
}

void BuffManager::ReleaseBuff(BuffNode* p)
{
	WaitForSingleObject(m_Lock, INFINITE);
	m_BuffManager.push_back(p);
	ReleaseMutex(m_Lock);

}



BuffManager g_BuffManager;