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engine.go
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engine.go
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// Copyright (C) 2023 Gobalsky Labs Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package settlement
import (
"context"
"sort"
"sync"
"time"
"code.vegaprotocol.io/vega/core/events"
"code.vegaprotocol.io/vega/core/metrics"
"code.vegaprotocol.io/vega/core/products"
"code.vegaprotocol.io/vega/core/types"
"code.vegaprotocol.io/vega/libs/num"
"code.vegaprotocol.io/vega/logging"
)
// MarketPosition ...
//
//go:generate go run github.com/golang/mock/mockgen -destination mocks/market_position_mock.go -package mocks code.vegaprotocol.io/vega/core/settlement MarketPosition
type MarketPosition interface {
Party() string
Size() int64
Buy() int64
Sell() int64
Price() *num.Uint
BuySumProduct() *num.Uint
SellSumProduct() *num.Uint
VWBuy() *num.Uint
VWSell() *num.Uint
ClearPotentials()
}
// Product ...
//
//go:generate go run github.com/golang/mock/mockgen -destination mocks/settlement_product_mock.go -package mocks code.vegaprotocol.io/vega/core/settlement Product
type Product interface {
Settle(*num.Uint, *num.Uint, num.Decimal) (*types.FinancialAmount, bool, num.Decimal, error)
GetAsset() string
}
// TimeService.
//
//go:generate go run github.com/golang/mock/mockgen -destination mocks/time_service_mock.go -package mocks code.vegaprotocol.io/vega/core/settlement TimeService
type TimeService interface {
GetTimeNow() time.Time
}
// Broker - the event bus broker, send events here.
type Broker interface {
Send(event events.Event)
SendBatch(events []events.Event)
}
// Engine - the main type (of course).
type Engine struct {
Config
log *logging.Logger
market string
product Product
settledPosition map[string]int64 // party -> last mark-to-market position
mu *sync.Mutex
trades map[string][]*settlementTrade
timeService TimeService
broker Broker
positionFactor num.Decimal
lastMarkPrice *num.Uint // price at last mark to market
}
// New instantiates a new instance of the settlement engine.
func New(log *logging.Logger, conf Config, product Product, market string, timeService TimeService, broker Broker, positionFactor num.Decimal) *Engine {
// setup logger
log = log.Named(namedLogger)
log.SetLevel(conf.Level.Get())
return &Engine{
Config: conf,
log: log,
market: market,
product: product,
settledPosition: map[string]int64{},
mu: &sync.Mutex{},
trades: map[string][]*settlementTrade{},
timeService: timeService,
broker: broker,
positionFactor: positionFactor,
}
}
func (e *Engine) UpdateProduct(product products.Product) {
e.product = product
}
// ReloadConf update the internal configuration of the settlement engined.
func (e *Engine) ReloadConf(cfg Config) {
e.log.Info("reloading configuration")
if e.log.GetLevel() != cfg.Level.Get() {
e.log.Info("updating log level",
logging.String("old", e.log.GetLevel().String()),
logging.String("new", cfg.Level.String()),
)
e.log.SetLevel(cfg.Level.Get())
}
e.Config = cfg
}
// Update merely adds positions to the settlement engine, and won't be useful for a MTM settlement
// this function is mainly used for testing, and should be used with extreme caution as a result
// perhaps the tests should be refactored to use the Settle call to create positions first.
func (e *Engine) Update(positions []events.MarketPosition) {
e.mu.Lock()
for _, p := range positions {
party := p.Party()
e.settledPosition[party] = p.Size()
e.lastMarkPrice = p.Price()
}
e.mu.Unlock()
}
// Settle run settlement over all the positions.
func (e *Engine) Settle(t time.Time, settlementData *num.Uint) ([]*types.Transfer, *num.Uint, error) {
e.log.Debugf("Settling market, closed at %s", t.Format(time.RFC3339))
positions, round, err := e.settleAll(settlementData)
if err != nil {
e.log.Error(
"Something went wrong trying to settle positions",
logging.Error(err),
)
return nil, nil, err
}
return positions, round, nil
}
// AddTrade - this call is required to get the correct MTM settlement values
// each change in position has to be calculated using the exact price of the trade.
func (e *Engine) AddTrade(trade *types.Trade) {
e.mu.Lock()
var buyerSize, sellerSize int64
// checking the len of cd shouldn't be required here, but it is needed in the second if
// in case the buyer and seller are one and the same...
if cd, ok := e.trades[trade.Buyer]; !ok || len(cd) == 0 {
e.trades[trade.Buyer] = []*settlementTrade{}
// check if the buyer already has a known position
if pos, ok := e.settledPosition[trade.Buyer]; ok {
buyerSize = pos
}
} else {
buyerSize = cd[len(cd)-1].newSize
}
if cd, ok := e.trades[trade.Seller]; !ok || len(cd) == 0 {
e.trades[trade.Seller] = []*settlementTrade{}
// check if seller has a known position
if pos, ok := e.settledPosition[trade.Seller]; ok {
sellerSize = pos
}
} else {
sellerSize = cd[len(cd)-1].newSize
}
size := int64(trade.Size)
// the parties both need to get a MTM settlement on the traded volume
// and this MTM part has to be based on the _actual_ trade value
price := trade.Price.Clone()
e.trades[trade.Buyer] = append(e.trades[trade.Buyer], &settlementTrade{
price: price,
marketPrice: trade.MarketPrice,
size: size,
newSize: buyerSize + size,
})
e.trades[trade.Seller] = append(e.trades[trade.Seller], &settlementTrade{
price: price.Clone(),
marketPrice: trade.MarketPrice,
size: -size,
newSize: sellerSize - size,
})
e.mu.Unlock()
}
func (e *Engine) HasTraded() bool {
return len(e.trades) > 0
}
func (e *Engine) getFundingTransfer(mtmShare *num.Uint, neg bool, mpos events.MarketPosition, owner string) (*mtmTransfer, bool) {
tf := e.getMtmTransfer(mtmShare, neg, mpos, owner)
if tf.transfer == nil {
tf.transfer = &types.Transfer{
Type: types.TransferTypePerpFundingWin,
Owner: owner,
Amount: &types.FinancialAmount{
Amount: mtmShare,
Asset: e.product.GetAsset(),
},
}
return tf, false
}
if tf.transfer.Type == types.TransferTypeMTMLoss {
tf.transfer.Type = types.TransferTypePerpFundingLoss
} else {
tf.transfer.Type = types.TransferTypePerpFundingWin
}
return tf, true
}
func (e *Engine) getMtmTransfer(mtmShare *num.Uint, neg bool, mpos events.MarketPosition, owner string) *mtmTransfer {
if mtmShare.IsZero() {
return &mtmTransfer{
MarketPosition: mpos,
transfer: nil,
}
}
typ := types.TransferTypeMTMWin
if neg {
typ = types.TransferTypeMTMLoss
}
return &mtmTransfer{
MarketPosition: mpos,
transfer: &types.Transfer{
Type: typ,
Owner: owner,
Amount: &types.FinancialAmount{
Amount: mtmShare,
Asset: e.product.GetAsset(),
},
},
}
}
func (e *Engine) winSocialisationUpdate(transfer *mtmTransfer, amt *num.Uint) {
if amt.IsZero() {
return
}
if transfer.transfer == nil {
transfer.transfer = &types.Transfer{
Type: types.TransferTypeMTMWin,
Owner: transfer.Party(),
Amount: &types.FinancialAmount{
Amount: num.UintZero(),
Asset: e.product.GetAsset(),
},
}
}
transfer.transfer.Amount.Amount.AddSum(amt)
}
func (e *Engine) SettleMTM(ctx context.Context, markPrice *num.Uint, positions []events.MarketPosition) []events.Transfer {
timer := metrics.NewTimeCounter("-", "settlement", "SettleOrder")
defer func() { e.lastMarkPrice = markPrice.Clone() }()
e.mu.Lock()
tCap := e.transferCap(positions)
transfers := make([]events.Transfer, 0, tCap)
// roughly half of the transfers should be wins, half losses
wins := make([]events.Transfer, 0, tCap/2)
trades := e.trades
e.trades = map[string][]*settlementTrade{} // remove here, once we've processed it all here, we're done
evts := make([]events.Event, 0, len(positions))
var (
largestShare *mtmTransfer // pointer to whomever gets the last remaining amount from the loss
zeroShares = []*mtmTransfer{} // all zero shares for equal distribution if possible
zeroAmts = false
mtmDec = num.NewDecimalFromFloat(0)
lossTotal = num.UintZero()
winTotal = num.UintZero()
lossTotalDec = num.NewDecimalFromFloat(0)
winTotalDec = num.NewDecimalFromFloat(0)
)
// Process any network trades first
traded, hasTraded := trades[types.NetworkParty]
if hasTraded {
// don't create an event for the network. Its position is irrelevant
mtmShare, mtmDShare, neg := calcMTM(markPrice, markPrice, 0, traded, e.positionFactor)
// MarketPosition stub for network
netMPos := &npos{
price: markPrice.Clone(),
}
mtmTransfer := e.getMtmTransfer(mtmShare.Clone(), neg, netMPos, types.NetworkParty)
if !neg {
wins = append(wins, mtmTransfer)
winTotal.AddSum(mtmShare)
winTotalDec = winTotalDec.Add(mtmDShare)
mtmDec = mtmDShare
largestShare = mtmTransfer
// mtmDec is zero at this point, this will always be the largest winning party at this point
if mtmShare.IsZero() {
zeroShares = append(zeroShares, mtmTransfer)
zeroAmts = true
}
} else if mtmShare.IsZero() {
// This would be a zero-value loss, so not sure why this would be at the end of the slice
// shouldn't really matter if this is in the wins or losses part of the slice, but
// this was the previous behaviour, so let's keep it
wins = append(wins, mtmTransfer)
lossTotalDec = lossTotalDec.Add(mtmDShare)
} else {
transfers = append(transfers, mtmTransfer)
lossTotal.AddSum(mtmShare)
lossTotalDec = lossTotalDec.Add(mtmDShare)
}
}
for _, evt := range positions {
party := evt.Party()
current, lastSettledPrice := e.getOrCreateCurrentPosition(party, evt.Size())
traded, hasTraded = trades[party]
tradeset := make([]events.TradeSettlement, 0, len(traded))
// empty position
skip := current == 0 && lastSettledPrice.IsZero() && evt.Buy() == 0 && evt.Sell() == 0
for _, t := range traded {
tradeset = append(tradeset, t)
}
// create (and add position to buffer)
evts = append(evts, events.NewSettlePositionEvent(ctx, party, e.market, evt.Price(), tradeset, e.timeService.GetTimeNow().UnixNano(), e.positionFactor))
// no changes in position, and the MTM price hasn't changed, we don't need to do anything
// or an empty position that isn't the result of the party closing itself out
if !hasTraded && (lastSettledPrice.EQ(markPrice) || skip) {
// no changes in position and markPrice hasn't changed -> nothing needs to be marked
continue
}
// calculate MTM value, we need the signed mark-price, the OLD open position/volume
// the new position is either the same, or accounted for by the traded var (added trades)
// and the old mark price at which the party held the position
// the trades slice contains all trade positions (position changes for the party)
// at their exact trade price, so we can MTM that volume correctly, too
mtmShare, mtmDShare, neg := calcMTM(markPrice, lastSettledPrice, current, traded, e.positionFactor)
// we've marked this party to market, their position can now reflect this
e.settledPosition[party] = evt.Size()
// we don't want to accidentally MTM a party who closed out completely when they open
// a new position at a later point, so remove if size == 0
if evt.Size() == 0 && evt.Buy() == 0 && evt.Sell() == 0 {
// broke this up into its own func for symmetry
e.rmPosition(party)
}
// there's still a subset of potential-only positions, their MTM will be zero
// but they don't hold an open position, and are excluded from win-socialisation.
skip = !hasTraded && evt.Size() == 0
posEvent := newPos(evt, markPrice)
mtmTransfer := e.getMtmTransfer(mtmShare.Clone(), neg, posEvent, party)
if !neg {
wins = append(wins, mtmTransfer)
winTotal.AddSum(mtmShare)
winTotalDec = winTotalDec.Add(mtmDShare)
if !skip && mtmShare.IsZero() {
zeroShares = append(zeroShares, mtmTransfer)
zeroAmts = true
}
if mtmDShare.GreaterThan(mtmDec) {
mtmDec = mtmDShare
largestShare = mtmTransfer
}
} else if mtmShare.IsZero() {
// zero value loss
wins = append(wins, mtmTransfer)
lossTotalDec = lossTotalDec.Add(mtmDShare)
} else {
transfers = append(transfers, mtmTransfer)
lossTotal.AddSum(mtmShare)
lossTotalDec = lossTotalDec.Add(mtmDShare)
}
}
// no need for this lock anymore
e.mu.Unlock()
delta := num.UintZero().Sub(lossTotal, winTotal)
if !delta.IsZero() {
if zeroAmts {
zRound := num.DecimalFromInt64(int64(len(zeroShares)))
// there are more transfers from losses than we pay out to wins, but some winning parties have zero transfers
// this delta should == combined win decimals, let's sanity check this!
if winTotalDec.LessThan(lossTotalDec) && winTotalDec.LessThan(lossTotalDec.Sub(zRound)) {
e.log.Panic("There's less MTM wins than losses, even accounting for decimals",
logging.Decimal("total loss", lossTotalDec),
logging.Decimal("total wins", winTotalDec),
)
}
// parties with a zero win transfer should get AT MOST a transfer of value 1
// any remainder after that should go to the largest win share, unless we only have parties
// with a win share of 0. that shouldn't be possible however, and so we can ignore that case
// should this happen at any point, the collateral engine will panic on settlement balance > 0
// which is the correct behaviour
// start distributing the delta
one := num.NewUint(1)
for _, transfer := range zeroShares {
e.winSocialisationUpdate(transfer, one)
delta.Sub(delta, one)
if delta.IsZero() {
break // all done
}
}
}
// delta is whatever amount the largest share win party gets, this shouldn't be too much
// delta can be zero at this stage, which is fine
e.winSocialisationUpdate(largestShare, delta)
}
// append wins after loss transfers
transfers = append(transfers, wins...)
e.broker.SendBatch(evts)
timer.EngineTimeCounterAdd()
return transfers
}
// RemoveDistressed - remove whatever settlement data we have for distressed parties
// they are being closed out, and shouldn't be part of any MTM settlement or closing settlement.
func (e *Engine) RemoveDistressed(ctx context.Context, evts []events.Margin) {
devts := make([]events.Event, 0, len(evts))
e.mu.Lock()
for _, v := range evts {
key := v.Party()
margin := num.Sum(v.MarginBalance(), v.GeneralBalance())
devts = append(devts, events.NewSettleDistressed(ctx, key, e.market, v.Price(), margin, e.timeService.GetTimeNow().UnixNano()))
delete(e.settledPosition, key)
delete(e.trades, key)
}
e.mu.Unlock()
e.broker.SendBatch(devts)
}
// simplified settle call.
func (e *Engine) settleAll(settlementData *num.Uint) ([]*types.Transfer, *num.Uint, error) {
e.mu.Lock()
// there should be as many positions as there are parties (obviously)
aggregated := make([]*types.Transfer, 0, len(e.settledPosition))
// parties who are in profit should be appended (collect first).
// The split won't always be 50-50, but it's a reasonable approximation
owed := make([]*types.Transfer, 0, len(e.settledPosition)/2)
// ensure we iterate over the positions in the same way by getting all the parties (keys)
// and sort them
keys := make([]string, 0, len(e.settledPosition))
for p := range e.settledPosition {
keys = append(keys, p)
}
sort.Strings(keys)
var delta num.Decimal
for _, party := range keys {
pos := e.settledPosition[party]
// this is possible now, with the Mark to Market stuff, it's possible we've settled any and all positions for a given party
if pos == 0 {
continue
}
e.log.Debug("Settling position for party", logging.String("party-id", party))
// @TODO - there was something here... the final amount had to be oracle - market or something
amt, neg, rem, err := e.product.Settle(e.lastMarkPrice, settlementData.Clone(), num.DecimalFromInt64(pos).Div(e.positionFactor))
// for now, product.Settle returns the total value, we need to only settle the delta between a parties current position
// and the final price coming from the oracle, so oracle_price - mark_price * volume (check with Tamlyn whether this should be absolute or not)
if err != nil {
e.log.Error(
"Failed to settle position for party",
logging.String("party-id", party),
logging.Error(err),
)
e.mu.Unlock()
return nil, nil, err
}
settlePos := &types.Transfer{
Owner: party,
Amount: amt,
}
e.log.Debug(
"Settled position for party",
logging.String("party-id", party),
logging.String("amount", amt.Amount.String()),
)
if neg { // this is a loss transfer
settlePos.Type = types.TransferTypeLoss
aggregated = append(aggregated, settlePos)
// truncated loss amount will not be transferred to the settlement balance
// so remove it from the total delta (aka rounding)
delta = delta.Sub(rem)
} else { // this is a win transfer
settlePos.Type = types.TransferTypeWin
owed = append(owed, settlePos)
// Truncated win transfer won't be withdrawn from the settlement balance
// so add it to the total delta (aka rounding)
delta = delta.Add(rem)
}
}
// we only care about the int part
round := num.UintZero()
// if delta > 0, the settlement account will have a non-zero balance at the end
if !delta.IsNegative() {
round, _ = num.UintFromDecimal(delta)
}
// append the parties in profit to the end
aggregated = append(aggregated, owed...)
e.mu.Unlock()
return aggregated, round, nil
}
func (e *Engine) getOrCreateCurrentPosition(party string, size int64) (int64, *num.Uint) {
p, ok := e.settledPosition[party]
if !ok {
e.settledPosition[party] = size
return 0, num.UintZero()
}
return p, e.lastMarkPrice
}
func (e *Engine) HasPosition(party string) bool {
_, okPos := e.settledPosition[party]
_, okTrades := e.trades[party]
return okPos && okTrades
}
func (e *Engine) rmPosition(party string) {
delete(e.settledPosition, party)
}
// just get the max len as cap.
func (e *Engine) transferCap(evts []events.MarketPosition) int {
curLen, evtLen := len(e.settledPosition), len(evts)
if curLen >= evtLen {
return curLen
}
return evtLen
}
// party.PREV_OPEN_VOLUME * (product.value(current_price) - product.value(prev_mark_price)) + SUM(from i=1 to new_trades.length)( new_trade(i).volume(party) * (product.value(current_price) - new_trade(i).price ) )
// the sum bit is a worry, we do not have all the trades available at this point...
// calcMTM only handles futures ATM. The formula is simple:
// amount = prev_vol * (current_price - prev_mark_price) + SUM(new_trade := range trades)( new_trade(i).volume(party)*(current_price - new_trade(i).price )
// given that the new trades price will equal new mark price, the sum(trades) bit will probably == 0 for nicenet
// the size here is the _new_ position size, the price is the OLD price!!
func calcMTM(markPrice, price *num.Uint, size int64, trades []*settlementTrade, positionFactor num.Decimal) (*num.Uint, num.Decimal, bool) {
delta, sign := num.UintZero().Delta(markPrice, price)
// this shouldn't be possible I don't think, but just in case
if size < 0 {
size = -size
// swap sign
sign = !sign
}
mtmShare := delta.Mul(delta, num.NewUint(uint64(size)))
for _, c := range trades {
delta, neg := num.UintZero().Delta(markPrice, c.price)
size := num.NewUint(uint64(c.size))
if c.size < 0 {
size = size.SetUint64(uint64(-c.size))
neg = !neg
}
add := delta.Mul(delta, size)
if mtmShare.IsZero() {
mtmShare.Set(add)
sign = neg
} else if neg == sign {
// both mtmShare and add are the same sign
mtmShare = mtmShare.Add(mtmShare, add)
} else if mtmShare.GTE(add) {
// regardless of sign, we just have to subtract
mtmShare = mtmShare.Sub(mtmShare, add)
} else {
// add > mtmShare, we don't care about signs here
// just subtract mtmShare and switch signs
mtmShare = add.Sub(add, mtmShare)
sign = neg
}
}
// as mtmShare was calculated with the volumes as integers (not decimals in pdp space) we need to divide by position factor
decShare := mtmShare.ToDecimal().Div(positionFactor)
res, _ := num.UintFromDecimal(decShare)
return res, decShare, sign
}
// SettleFundingPeriod takes positions and a funding-payement and returns a slice of transfers.
// returns the slice of transfers to perform, and the max remainder on the settlement account due to rounding issues.
func (e *Engine) SettleFundingPeriod(ctx context.Context, positions []events.MarketPosition, fundingPayment *num.Int) ([]events.Transfer, *num.Uint) {
if fundingPayment.IsZero() || len(positions) == 0 {
// nothing to do here
return nil, nil
}
// colletral engine expects all the losses before the wins
transfers := make([]events.Transfer, 0, len(positions))
wins := make([]events.Transfer, 0, len(positions))
zeroTransfers := make([]events.Transfer, 0, len(positions)/2)
totalW, totalL := num.UintZero(), num.UintZero()
var delta num.Decimal
for _, p := range positions {
// per-party cash flow is -openVolume * fundingPayment
flow, rem, neg := calcFundingFlow(fundingPayment, p, e.positionFactor)
if neg {
// amount of loss not collected, this never gets added to the settlement account
delta = delta.Sub(rem)
} else {
// amount of wins never collected, remains in the settlement account
delta = delta.Add(rem)
}
if tf, valid := e.getFundingTransfer(flow, neg, p, p.Party()); valid {
if tf.transfer.Type == types.TransferTypePerpFundingWin {
wins = append(wins, tf)
totalW.AddSum(flow)
} else {
transfers = append(transfers, tf)
totalL.AddSum(flow)
}
} else {
// we could use deltas to order these transfers to prioritise the right people
zeroTransfers = append(zeroTransfers, tf)
}
if e.log.IsDebug() {
e.log.Debug("cash flow", logging.String("mid", e.market), logging.String("pid", p.Party()), logging.String("flow", flow.String()))
}
}
// account for cases where the winning side never even accounts for an amount of 1
if len(wins) == 0 && len(zeroTransfers) > 0 {
wins = zeroTransfers
}
// profit and loss balances out perfectly, or profit > loss
if totalL.LTE(totalW) {
// this rounding shouldn't be needed, losses will be distributed in their entirety
round, _ := num.UintFromDecimal(delta.Abs())
return append(transfers, wins...), round
}
round := totalL.Sub(totalL, totalW) // loss - win is what will be left over
// we have a remainder, make sure it's an expected amount due to rounding
if dU, _ := num.UintFromDecimal(delta.Ceil().Abs()); dU.LT(round) {
e.log.Panic("Excess loss transfer amount found, cannot be explained by rounding",
logging.String("loss-win delta", round.String()),
logging.Decimal("rounding delta", delta.Abs()),
)
}
return append(transfers, wins...), round
}
func calcFundingFlow(fp *num.Int, p events.MarketPosition, posFac num.Decimal) (*num.Uint, num.Decimal, bool) {
// -openVolume * fundingPayment
// divide by position factor to account for position decimal places
flowD := num.DecimalFromInt64(-p.Size()).Mul(num.DecimalFromInt(fp)).Div(posFac)
neg := flowD.IsNegative()
flow, frac := num.UintFromDecimalWithFraction(flowD.Abs())
return flow, frac, neg
}