// Copyright 2008-2018 Yolo Technologies, Inc. All Rights Reserved. https://www.comblockengine.com



#include "baseapp.h"
#include "backuper.h"
#include "server/serverconfig.h"
#include <random>


namespace KBEngine{	

float backupPeriod = 0.0;



//-------------------------------------------------------------------------------------

Backuper::Backuper():

backupEntityIDs_(),

backupRemainder_(0.f)

{

}



//-------------------------------------------------------------------------------------

Backuper::~Backuper()

{

	backupEntityIDs_.clear();

}



//-------------------------------------------------------------------------------------

void Backuper::tick()

{

	int32 periodInTicks = (int32)secondsToTicks(ServerConfig::getSingleton().getBaseApp().backupPeriod, 0);

	if (periodInTicks == 0)

		return;



	// 这里对备份的entity做一下分批操作

	// 大概算法是配置上填写的备份周期换算成tick数量， 每个tick备份一部分entity

	float numToBackUpFloat = float(Baseapp::getSingleton().pEntities()->size()) / periodInTicks + backupRemainder_;



	// 本次备份的数量

	int numToBackUp = int(numToBackUpFloat);



	// 计算出精度导致的损失数量

	backupRemainder_ = numToBackUpFloat - numToBackUp;



	// 如果备份表中没有内容了则重新产生一份新的

	if (backupEntityIDs_.empty())

	{

		this->createBackupTable();

	}



	MemoryStream* s = MemoryStream::createPoolObject(OBJECTPOOL_POINT);

	

	while((numToBackUp > 0) && !backupEntityIDs_.empty())

	{

		Entity * pEntity = Baseapp::getSingleton().findEntity(backupEntityIDs_.back());

		backupEntityIDs_.pop_back();

		

		if (pEntity && backup(*pEntity, *s))

		{

			--numToBackUp;

		}

		

		s->clear(false);

	}

	

	MemoryStream::reclaimPoolObject(s);

}



//-------------------------------------------------------------------------------------

bool Backuper::backup(Entity& entity, MemoryStream& s)

{

	// 这里开始将需要备份的数据写入流

	entity.writeBackupData(&s);



	if(entity.shouldAutoBackup() == KBE_NEXT_ONLY)

		entity.shouldAutoBackup(0);



	return true;

}



//-------------------------------------------------------------------------------------

void Backuper::createBackupTable()

{

	backupEntityIDs_.clear();



	Entities<Entity>::ENTITYS_MAP::const_iterator iter = Baseapp::getSingleton().pEntities()->getEntities().begin();



	for(; iter != Baseapp::getSingleton().pEntities()->getEntities().end(); ++iter)

	{

		Entity* pEntity = static_cast<Entity*>(iter->second.get());



		if(pEntity->shouldAutoBackup() > 0)

			backupEntityIDs_.push_back(iter->first);

	}

	// 随机一下序列
	static thread_local std::mt19937 rng(std::random_device{}());
	std::shuffle(backupEntityIDs_.begin(), backupEntityIDs_.end(), rng);
}

}