SETUP_LOG (LoadManager)

LoadManager::LoadManager (int creditRate, int creditLimit, int debitWarn, int debitLimit)
	: mCreditRate(creditRate)
	, mCreditLimit(creditLimit)
	, mDebitWarn(debitWarn)
	, mDebitLimit(debitLimit)
	, mShutdown(false)
	, mArmed(false)
	, mDeadLock(0)
	, mCosts(LT_MAX)
{
	addLoadCost(LoadCost(LT_InvalidRequest,		-10,		LC_CPU | LC_Network));
	addLoadCost(LoadCost(LT_RequestNoReply,		-1,		LC_CPU | LC_Disk));
	addLoadCost(LoadCost(LT_InvalidSignature,	-100,	LC_CPU));
	addLoadCost(LoadCost(LT_UnwantedData,		-5,		LC_CPU | LC_Network));
	addLoadCost(LoadCost(LT_BadData,			-20,		LC_CPU));

	addLoadCost(LoadCost(LT_NewTrusted,			-10,		0));
	addLoadCost(LoadCost(LT_NewTransaction,		-2,		0));
	addLoadCost(LoadCost(LT_NeededData,			-10,		0));

	addLoadCost(LoadCost(LT_RequestData,		-5,		LC_Disk | LC_Network));
	addLoadCost(LoadCost(LT_CheapQuery,			-1,		LC_CPU));

}

void LoadManager::init()
{
	UptimeTimer::getInstance().beginManualUpdates ();

	boost::thread(boost::bind(&LoadManager::threadEntry, this)).detach();
}

LoadManager::~LoadManager()
{
	UptimeTimer::getInstance().endManualUpdates ();

    // VFALCO What is this loop? it doesn't seem to do anything useful.
	do
	{
		boost::this_thread::sleep(boost::posix_time::milliseconds(100));
		{
			boost::mutex::scoped_lock sl(mLock);
			if (!mShutdown)
				return;
		}
	}
	while (1);
}

void LoadManager::noDeadLock()
{
	boost::mutex::scoped_lock sl(mLock);
	//mDeadLock = mUptime;
	mDeadLock = UptimeTimer::getInstance ().getElapsedSeconds ();
}

int LoadManager::getCreditRate() const
{
	boost::mutex::scoped_lock sl(mLock);
	return mCreditRate;
}

int LoadManager::getCreditLimit() const
{
	boost::mutex::scoped_lock sl(mLock);
	return mCreditLimit;
}

int LoadManager::getDebitWarn() const
{
	boost::mutex::scoped_lock sl(mLock);
	return mDebitWarn;
}

int LoadManager::getDebitLimit() const
{
	boost::mutex::scoped_lock sl(mLock);
	return mDebitLimit;
}

void LoadManager::setCreditRate(int r)
{
	boost::mutex::scoped_lock sl(mLock);
	mCreditRate = r;
}

void LoadManager::setCreditLimit(int r)
{
	boost::mutex::scoped_lock sl(mLock);
	mCreditLimit = r;
}

void LoadManager::setDebitWarn(int r)
{
	boost::mutex::scoped_lock sl(mLock);
	mDebitWarn = r;
}

void LoadManager::setDebitLimit(int r)
{
	boost::mutex::scoped_lock sl(mLock);
	mDebitLimit = r;
}

void LoadManager::canonicalize(LoadSource& source, int now) const
{
	if (source.mLastUpdate != now)
	{
		if (source.mLastUpdate < now)
		{
			source.mBalance += mCreditRate * (now - source.mLastUpdate);
			if (source.mBalance > mCreditLimit)
			{
				source.mBalance = mCreditLimit;
				source.mLogged = false;
			}
		}
		source.mLastUpdate = now;
	}
}

bool LoadManager::shouldWarn(LoadSource& source) const
{
	{
		boost::mutex::scoped_lock sl(mLock);

		int now = UptimeTimer::getInstance().getElapsedSeconds ();
		canonicalize(source, now);
		if (source.isPrivileged() || (source.mBalance > mDebitWarn) || (source.mLastWarning == now))
			return false;

		source.mLastWarning = now;
	}
	logWarning(source.getName());
	return true;
}

bool LoadManager::shouldCutoff(LoadSource& source) const
{
	{
		boost::mutex::scoped_lock sl(mLock);
		int now = UptimeTimer::getInstance().getElapsedSeconds ();
		canonicalize(source, now);
		if (source.isPrivileged() || (source.mBalance > mDebitLimit))
			return false;
		if (source.mLogged)
			return true;
		source.mLogged = true;
	}
	logDisconnect(source.getName());
	return true;
}

bool LoadManager::adjust(LoadSource& source, LoadType t) const
{ // FIXME: Scale by category
	LoadCost cost = mCosts[static_cast<int>(t)];
	return adjust(source, cost.mCost);
}

bool LoadManager::adjust(LoadSource& source, int credits) const
{ // return: true = need to warn/cutoff

	// We do it this way in case we want to add exponential decay later
	int now = UptimeTimer::getInstance().getElapsedSeconds ();
	canonicalize(source, now);
	source.mBalance += credits;
	if (source.mBalance > mCreditLimit)
		source.mBalance = mCreditLimit;

	if (source.isPrivileged()) // privileged sources never warn/cutoff
		return false;

	if ((source.mBalance >= mDebitLimit) && (source.mLastWarning == now)) // no need to warn
		return false;

	return true;
}

static void LogDeadLock(int dlTime)
{
	WriteLog (lsWARNING, LoadManager) << "Server stalled for " << dlTime << " seconds.";
}

void LoadManager::threadEntry()
{
	setCallingThreadName ("loadmgr");

    // VFALCO TODO replace this with a beast Time object
	boost::posix_time::ptime t = boost::posix_time::microsec_clock::universal_time();
	while (1)
	{
		{
			boost::mutex::scoped_lock sl(mLock);
			if (mShutdown)
			{
				mShutdown = false;
				return;
			}
			
			UptimeTimer::getInstance ().incrementElapsedTime ();

			int dlTime = UptimeTimer::getInstance ().getElapsedSeconds () - mDeadLock;
			if (mArmed && (dlTime >= 10))
			{
				if ((dlTime % 10) == 0)
				{
					boost::thread(BIND_TYPE(&LogDeadLock, dlTime)).detach();
				}

				assert (dlTime < 500);
			}

		}

        // VFALCO TODO Eliminate the dependence on the Application object by
        //         constructing with the job queue and the fee tracker.
		bool change;
		if (theApp->getJobQueue().isOverloaded())
		{
			WriteLog (lsINFO, LoadManager) << theApp->getJobQueue().getJson(0);
			change = theApp->getFeeTrack().raiseLocalFee();
		}
		else
        {
			change = theApp->getFeeTrack().lowerLocalFee();
        }

        if (change)
        {
            // VFALCO TODO replace this with a Listener / observer and subscribe in NetworkOPs or Application
			theApp->getOPs().reportFeeChange();
        }

		t += boost::posix_time::seconds(1);
		boost::posix_time::time_duration when = t - boost::posix_time::microsec_clock::universal_time();

		if ((when.is_negative()) || (when.total_seconds() > 1))
		{
			WriteLog (lsWARNING, LoadManager) << "time jump";
			t = boost::posix_time::microsec_clock::universal_time();
		}
		else
			boost::this_thread::sleep(when);
	}
}

void LoadManager::logWarning(const std::string& source) const
{
	if (source.empty())
		WriteLog (lsDEBUG, LoadManager) << "Load warning from empty source";
	else
		WriteLog (lsINFO, LoadManager) << "Load warning: " << source;
}

void LoadManager::logDisconnect(const std::string& source) const
{
	if (source.empty())
		WriteLog (lsINFO, LoadManager) << "Disconnect for empty source";
	else
		WriteLog (lsWARNING, LoadManager) << "Disconnect for: " << source;
}

// vim:ts=4