[R4R] Fix pricefeed sims so does not always go to zero (#434)

* Generate pricefeed prices using a random walk at the beginning of sims

Co-authored-by: rhuairahrighairigh <ruaridh.odonnell@gmail.com>
Co-authored-by: John Maheswaran <john@kava.io>
Co-authored-by: Ruaridh <rhuairahrighairidh@users.noreply.github.com>
Co-authored-by: John Maheswaran <john@noreply>
Co-authored-by: Kevin Davis <karzak@users.noreply.github.com>
Co-authored-by: Kevin Davis <kjydavis3@gmail.com>
Co-authored-by: Denali Marsh <denali@kava.io>
This commit is contained in:
jmahess 2020-04-17 18:29:54 -04:00 committed by GitHub
parent 5ae0b76e0c
commit 55747ed0b8
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4 changed files with 124 additions and 83 deletions

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@ -304,7 +304,7 @@ func testAndRunTxs(app *App, config simulation.Config) []simulation.WeightedOper
})
return v
}(nil),
pricefeedsimops.SimulateMsgUpdatePrices(app.pricefeedKeeper),
pricefeedsimops.SimulateMsgUpdatePrices(app.pricefeedKeeper, config.NumBlocks),
},
{
func(_ *rand.Rand) int {

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@ -156,7 +156,7 @@ func SimulateMsgCdp(ak auth.AccountKeeper, k cdp.Keeper, pfk pricefeed.Keeper) s
// repay debt 25% of the time
if hasCoins(acc, randDebtParam.Denom) {
debt := (existingCDP.Principal.Add(existingCDP.AccumulatedFees)).AmountOf(randDebtParam.Denom)
debt := existingCDP.Principal.AmountOf(randDebtParam.Denom)
maxRepay := acc.GetCoins().AmountOf(randDebtParam.Denom)
payableDebt := debt.Sub(randDebtParam.DebtFloor)
if maxRepay.GT(payableDebt) {

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@ -12,51 +12,61 @@ import (
pricefeed "github.com/kava-labs/kava/x/pricefeed/types"
)
var (
// BaseAssets is a list of collateral asset denoms
BaseAssets = [3]string{"bnb", "xrp", "btc"}
QuoteAsset = "usd"
)
// RandomizedGenState generates a random GenesisState for pricefeed
func RandomizedGenState(simState *module.SimulationState) {
// get the params with xrp, btc and bnb to usd
// getPricefeedSimulationParams is defined to return params with xrp:usd, btc:usd, bnb:usd
params := getPricefeedSimulationParams()
markets := []types.Market{}
genPrices := []types.PostedPrice{}
// chose one account to be the oracle
oracle := simState.Accounts[simulation.RandIntBetween(simState.Rand, 0, len(simState.Accounts))]
for _, market := range params.Markets {
updatedMarket := types.Market{market.MarketID, market.BaseAsset, market.QuoteAsset, []sdk.AccAddress{oracle.Address}, true}
markets = append(markets, updatedMarket)
genPrice := types.PostedPrice{market.MarketID, oracle.Address, getInitialPrice(market.MarketID), simState.GenTimestamp.Add(time.Hour * 24)}
genPrices = append(genPrices, genPrice)
}
params = types.NewParams(markets)
pricefeedGenesis := types.NewGenesisState(params, genPrices)
pricefeedGenesis := loadPricefeedGenState(simState)
fmt.Printf("Selected randomly generated %s parameters:\n%s\n", types.ModuleName, codec.MustMarshalJSONIndent(simState.Cdc, pricefeedGenesis))
simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(pricefeedGenesis)
}
// getPricefeedSimulationParams returns the params with xrp:usd, btc:usd, bnb:usd
func getPricefeedSimulationParams() types.Params {
// SET UP THE PRICEFEED GENESIS STATE
pricefeedGenesis := pricefeed.GenesisState{
Params: pricefeed.Params{
Markets: []pricefeed.Market{
pricefeed.Market{MarketID: "btc:usd", BaseAsset: "btc", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
pricefeed.Market{MarketID: "xrp:usd", BaseAsset: "xrp", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
pricefeed.Market{MarketID: "bnb:usd", BaseAsset: "bnb", QuoteAsset: "usd", Oracles: []sdk.AccAddress{}, Active: true},
},
},
// loadPricefeedGenState loads a valid pricefeed gen state
func loadPricefeedGenState(simState *module.SimulationState) pricefeed.GenesisState {
var markets []pricefeed.Market
var postedPrices []pricefeed.PostedPrice
for _, denom := range BaseAssets {
// Select an account to be the oracle
oracle := simState.Accounts[simulation.RandIntBetween(simState.Rand, 0, len(simState.Accounts))]
marketID := fmt.Sprintf("%s:%s", denom, QuoteAsset)
// Construct market for asset
market := pricefeed.Market{
MarketID: marketID,
BaseAsset: denom,
QuoteAsset: QuoteAsset,
Oracles: []sdk.AccAddress{oracle.Address},
Active: true,
}
return pricefeedGenesis.Params
// Construct posted price for asset
postedPrice := pricefeed.PostedPrice{
MarketID: market.MarketID,
OracleAddress: oracle.Address,
Price: getInitialPrice(marketID),
Expiry: simState.GenTimestamp.Add(time.Hour * 24),
}
markets = append(markets, market)
postedPrices = append(postedPrices, postedPrice)
}
params := pricefeed.NewParams(markets)
return pricefeed.NewGenesisState(params, postedPrices)
}
// getInitialPrice gets the starting price for each of the base assets
func getInitialPrice(marketId string) (price sdk.Dec) {
switch marketId {
func getInitialPrice(marketID string) (price sdk.Dec) {
switch marketID {
case "btc:usd":
return sdk.MustNewDecFromStr("7000")
case "bnb:usd":
return sdk.MustNewDecFromStr("14")
case "xrp:usd":
return sdk.MustNewDecFromStr("0.2")
default:
return sdk.MustNewDecFromStr("20") // Catch future additional assets
}
panic(fmt.Sprintf("Invalid marketId in getInitialPrice: %s\n", marketId))
}

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@ -3,6 +3,7 @@ package operations
import (
"fmt"
"math/rand"
"sync"
"time"
"github.com/cosmos/cosmos-sdk/baseapp"
@ -16,43 +17,53 @@ import (
var (
noOpMsg = simulation.NoOpMsg(pricefeed.ModuleName)
btcPrices = []sdk.Dec{}
bnbPrices = []sdk.Dec{}
xrpPrices = []sdk.Dec{}
genPrices sync.Once
)
// SimulateMsgUpdatePrices updates the prices of various assets by randomly varying them based on current price
func SimulateMsgUpdatePrices(keeper keeper.Keeper) simulation.Operation {
func SimulateMsgUpdatePrices(keeper keeper.Keeper, blocks int) simulation.Operation {
// get a pricefeed handler
handler := pricefeed.NewHandler(keeper)
return func(r *rand.Rand, app *baseapp.BaseApp, ctx sdk.Context, accs []simulation.Account) (
simulation.OperationMsg, []simulation.FutureOperation, error) {
genPrices.Do(func() {
// generate a random walk for each asset exactly once, with observations equal to the number of blocks in the sim
for _, m := range keeper.GetMarkets(ctx) {
startPrice := getStartPrice(m.MarketID)
// allow prices to fluctuate from 10x GAINZ to 100x REKT
maxPrice := sdk.MustNewDecFromStr("10.0").Mul(startPrice)
minPrice := sdk.MustNewDecFromStr("0.01").Mul(startPrice)
previousPrice := startPrice
for i := 0; i < blocks; i++ {
increment := getIncrement(m.MarketID)
// note calling r instead of rand here breaks determinism
upDown := rand.Intn(2)
if upDown == 0 {
if previousPrice.Add(increment).GT(maxPrice) {
previousPrice = maxPrice
} else {
previousPrice = previousPrice.Add(increment)
}
} else {
if previousPrice.Sub(increment).LT(minPrice) {
previousPrice = minPrice
} else {
previousPrice = previousPrice.Sub(increment)
}
}
setPrice(m.MarketID, previousPrice)
}
}
})
// OVERALL LOGIC:
// (1) RANDOMLY PICK AN ASSET OUT OF BNB AN BTC [TODO QUESTION - USDX IS EXCLUDED AS IT IS A STABLE DENOM
// (2) GET THE CURRENT PRICE OF THAT ASSET IN USD
// (3) GENERATE A RANDOM NUMBER IN THE RANGE 0.8-1.2 (UNIFORM DISTRIBUTION)
// (4) MULTIPLY THE CURRENT PRICE BY THE RANDOM NUMBER
// (5) POST THE NEW PRICE TO THE KEEPER
// pick a random asset out of BNB and BTC
randomMarket := pickRandomAsset(ctx, keeper, r)
marketID := randomMarket.MarketID
// Get the current price of the asset
currentPrice, err := keeper.GetCurrentPrice(ctx, marketID) // Note this is marketID AND **NOT** just the base asset
if err != nil {
return noOpMsg, nil, fmt.Errorf("Error getting current price")
}
// get the address for the account
// this address needs to be an oracle and also exist. genesis should add all the accounts as oracles.
address := getRandomOracle(r, randomMarket)
// generate a new random price based off the current price
price, err := pickNewRandomPrice(r, currentPrice.Price)
if err != nil {
return noOpMsg, nil, fmt.Errorf("Error picking random price")
}
price := pickNewRandomPrice(marketID, int(ctx.BlockHeight()))
// get the expiry time based off the current time
expiry := getExpiryTime(ctx)
@ -73,6 +84,51 @@ func SimulateMsgUpdatePrices(keeper keeper.Keeper) simulation.Operation {
}
}
func getStartPrice(marketID string) (startPrice sdk.Dec) {
switch marketID {
case "btc:usd":
return sdk.MustNewDecFromStr("7000")
case "bnb:usd":
return sdk.MustNewDecFromStr("15")
case "xrp:usd":
return sdk.MustNewDecFromStr("0.25")
}
return sdk.MustNewDecFromStr("100")
}
func getIncrement(marketID string) (increment sdk.Dec) {
startPrice := getStartPrice(marketID)
divisor := sdk.MustNewDecFromStr("20")
increment = startPrice.Quo(divisor)
return increment
}
func setPrice(marketID string, price sdk.Dec) {
switch marketID {
case "btc:usd":
btcPrices = append(btcPrices, price)
return
case "bnb:usd":
bnbPrices = append(bnbPrices, price)
return
case "xrp:usd":
xrpPrices = append(xrpPrices, price)
}
return
}
func pickNewRandomPrice(marketID string, blockHeight int) (newPrice sdk.Dec) {
switch marketID {
case "btc:usd":
return btcPrices[blockHeight-1]
case "bnb:usd":
return bnbPrices[blockHeight-1]
case "xrp:usd":
return xrpPrices[blockHeight-1]
}
panic("invalid price request")
}
// getRandomOracle picks a random oracle from the list of oracles
func getRandomOracle(r *rand.Rand, market pricefeed.Market) sdk.AccAddress {
randomIndex := simulation.RandIntBetween(r, 0, len(market.Oracles))
@ -98,31 +154,6 @@ func getExpiryTime(ctx sdk.Context) (t time.Time) {
return t
}
// pickNewRandomPrice picks a new random price given the current price
// It takes the current price then generates a random number to multiply it by to create variation while
// still being in the similar range. Random walk style.
func pickNewRandomPrice(r *rand.Rand, currentPrice sdk.Dec) (price sdk.Dec, err sdk.Error) {
// Pick random price
// this is in the range [0-0.4) because when added to 0.8 it gives a multiplier in the range 0.8-1.2
got := sdk.MustNewDecFromStr("0.4")
randomPriceMultiplier := simulation.RandomDecAmount(r, got) // get a random number
if err != nil {
fmt.Errorf("Error generating random price multiplier\n")
return sdk.ZeroDec(), err
}
// 0.8 offset corresponds to 80% of the the current price
offset := sdk.MustNewDecFromStr("0.8")
// gives a result in range 0.8-1.2 inclusive, so the price can fluctuate from 80% to 120% of its current value
randomPriceMultiplier = randomPriceMultiplier.Add(offset)
// multiply the current price by the price multiplier
price = randomPriceMultiplier.Mul(currentPrice)
// return the price
return price, nil
}
// submitMsg submits a message to the current instance of the keeper and returns a boolean whether the operation completed successfully or not
func submitMsg(ctx sdk.Context, handler sdk.Handler, msg sdk.Msg) (ok bool) {
ctx, write := ctx.CacheContext()