/**
 * @file llthrottle.h
 * @brief LLThrottle class used for network bandwidth control
 *
 * $LicenseInfo:firstyear=2001&license=viewergpl$
 *
 * Copyright (c) 2001-2009, Linden Research, Inc.
 *
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 *
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 *
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#ifndef LL_LLTHROTTLE_H
#define LL_LLTHROTTLE_H

#include "llpreprocessor.h"
#include "lltimer.h"

constexpr S32 MAX_THROTTLE_SIZE = 32;

class LLDataPacker;

// Single instance of a generic throttle
class LLThrottle
{
public:
	LLThrottle(F32 throttle = 1.f);
	~LLThrottle()							{}

	void setRate(F32 rate);
	// About to add an amount, true if would overflow throttle
	bool checkOverflow(F32 amount);
	// Just sent amount, true if that overflowed the throttle
	bool throttleOverflow(F32 amount);

	F32 getAvailable();		// Returns the available bits

	LL_INLINE F32 getRate() const			{ return mRate; }

private:
	F32 mLookaheadSecs;		// Seconds to look ahead, maximum
	F32	mRate;				// bps available, dynamically adjusted
	F32	mAvailable;			// Bits available to send right now on each channel
	F64	mLastSendTime;		// Time since last send on this channel
};

typedef enum e_throttle_categories
{
	TC_RESEND,
	TC_LAND,
	TC_WIND,
	TC_CLOUD,
	TC_TASK,
	TC_TEXTURE,
	TC_ASSET,
	TC_EOF
} EThrottleCats;

class LLThrottleGroup
{
public:
	LLThrottleGroup();
	~LLThrottleGroup()						{}

	void resetDynamicAdjust();
	// About to send bits, true if would overflow channel
	bool checkOverflow(S32 throttle_cat, F32 bits);
	// Just sent bits, true if that overflowed the channel
	bool throttleOverflow(S32 throttle_cat, F32 bits);
	// Shift bandwidth from idle channels to busy channels, true if adjustment
	// occurred
	bool dynamicAdjust();
	// true if any value was different, resets adjustment system if was
	// different
	bool setNominalBPS(F32* throttle_vec);

	// Returns bits available in the channel
	S32 getAvailable(S32 throttle_cat);

	void packThrottle(LLDataPacker& dp) const;
	void unpackThrottle(LLDataPacker& dp);

public:
	// bps available, sent by viewer, sum for all simulators
	F32		mThrottleTotal[TC_EOF];

protected:
	// bps available, adjusted to be just this simulator
	F32		mNominalBPS[TC_EOF];
	// bps available, dynamically adjusted
	F32		mCurrentBPS[TC_EOF];

	// Bits available to send right now on each channel
	F32		mBitsAvailable[TC_EOF];
	// Sent in this dynamic allocation period
	F32		mBitsSentThisPeriod[TC_EOF];
	// Sent before this dynamic allocation period, adjusted to one period
	// length
	F32		mBitsSentHistory[TC_EOF];
	// Time since last send on this channel
	F64		mLastSendTime[TC_EOF];
	// Only dynamic adjust every 2 seconds or so.
	F64		mDynamicAdjustTime;
};

#endif