fix: simplify collateral auction logic

This commit is contained in:
Kevin Davis 2020-05-11 18:35:16 -04:00
parent d489bacfac
commit 89b63a3cba
3 changed files with 34 additions and 145 deletions

View File

@ -1,8 +1,6 @@
package keeper
import (
"fmt"
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/kava-labs/kava/x/cdp/types"
@ -13,100 +11,15 @@ const (
dump = 100
)
type partialDeposit struct {
Depositor sdk.AccAddress
Amount sdk.Coin
DebtShare sdk.Int
}
func newPartialDeposit(depositor sdk.AccAddress, amount sdk.Coin, ds sdk.Int) partialDeposit {
return partialDeposit{
Depositor: depositor,
Amount: amount,
DebtShare: ds,
}
}
type partialDeposits []partialDeposit
func (pd partialDeposits) SumCollateral() (sum sdk.Int) {
sum = sdk.ZeroInt()
for _, d := range pd {
sum = sum.Add(d.Amount.Amount)
}
return
}
func (pd partialDeposits) SumDebt() (sum sdk.Int) {
sum = sdk.ZeroInt()
for _, d := range pd {
sum = sum.Add(d.DebtShare)
}
return
}
// AuctionCollateral creates auctions from the input deposits which attempt to raise the corresponding amount of debt
func (k Keeper) AuctionCollateral(ctx sdk.Context, deposits types.Deposits, debt sdk.Int, bidDenom string) error {
auctionSize := k.getAuctionSize(ctx, deposits[0].Amount.Denom)
partialAuctionDeposits := partialDeposits{}
totalCollateral := deposits.SumCollateral()
for totalCollateral.GT(sdk.ZeroInt()) {
for i, dep := range deposits {
if dep.Amount.IsZero() {
continue
}
collateralAmount := dep.Amount.Amount
collateralDenom := dep.Amount.Denom
// create auctions from individual deposits that are larger than the auction size
debtChange, collateralChange, err := k.CreateAuctionsFromDeposit(ctx, dep, debt, totalCollateral, auctionSize, bidDenom)
if err != nil {
return err
}
fmt.Printf("AuctionCollateral:createFromD:loop%d:liquidator:%s\n", i, k.supplyKeeper.GetModuleAccount(ctx, types.LiquidatorMacc))
debt = debt.Sub(debtChange)
totalCollateral = totalCollateral.Sub(collateralChange)
dep.Amount = sdk.NewCoin(collateralDenom, collateralAmount.Sub(collateralChange))
collateralAmount = collateralAmount.Sub(collateralChange)
// if there is leftover collateral that is less than a lot
if !dep.Amount.IsZero() {
// figure out how much debt this deposit accounts for
// (depositCollateral / totalCollateral) * totalDebtFromCDP
debtCoveredByDeposit := collateralAmount.Mul(debt).Quo(totalCollateral) // integer division (ie rounds down)
// if adding this deposit to the other partial deposits is less than a lot
if (partialAuctionDeposits.SumCollateral().Add(collateralAmount)).LT(auctionSize) {
// append the deposit to the partial deposits and zero out the deposit
pd := newPartialDeposit(dep.Depositor, dep.Amount, debtCoveredByDeposit)
partialAuctionDeposits = append(partialAuctionDeposits, pd)
dep.Amount = sdk.NewCoin(collateralDenom, sdk.ZeroInt())
} else {
// if the sum of partial deposits now makes a lot
partialCollateral := sdk.NewCoin(collateralDenom, auctionSize.Sub(partialAuctionDeposits.SumCollateral()))
partialAmount := partialCollateral.Amount
partialDebt := partialAmount.Mul(debtCoveredByDeposit).Quo(collateralAmount) // integer division (ie rounds down)
// create a partial deposit from the deposit
partialDep := newPartialDeposit(dep.Depositor, partialCollateral, partialDebt)
// append it to the partial deposits
partialAuctionDeposits = append(partialAuctionDeposits, partialDep)
// create an auction from the partial deposits
debtChange, collateralChange, err := k.CreateAuctionFromPartialDeposits(ctx, partialAuctionDeposits, debt, totalCollateral, auctionSize, bidDenom)
if err != nil {
return err
}
fmt.Printf("AuctionCollateral:createFromPD:loop%d:liquidator:%s\n", i, k.supplyKeeper.GetModuleAccount(ctx, types.LiquidatorMacc))
debt = debt.Sub(debtChange)
totalCollateral = totalCollateral.Sub(collateralChange)
// reset partial deposits and update the deposit amount
partialAuctionDeposits = partialDeposits{}
dep.Amount = sdk.NewCoin(collateralDenom, collateralAmount.Sub(partialAmount))
}
}
deposits[i] = dep
totalCollateral = deposits.SumCollateral()
}
}
if partialAuctionDeposits.SumCollateral().GT(sdk.ZeroInt()) {
_, _, err := k.CreateAuctionFromPartialDeposits(ctx, partialAuctionDeposits, debt, totalCollateral, partialAuctionDeposits.SumCollateral(), bidDenom)
auctionSize := k.getAuctionSize(ctx, deposits[0].Amount.Denom)
totalCollateral := deposits.SumCollateral()
for _, deposit := range deposits {
debtCoveredByDeposit := (sdk.NewDecFromInt(deposit.Amount.Amount).Quo(sdk.NewDecFromInt(totalCollateral))).Mul(sdk.NewDecFromInt(debt)).RoundInt()
err := k.CreateAuctionsFromDeposit(ctx, deposit.Amount, deposit.Depositor, debtCoveredByDeposit, auctionSize, bidDenom)
if err != nil {
return err
}
@ -114,54 +27,37 @@ func (k Keeper) AuctionCollateral(ctx sdk.Context, deposits types.Deposits, debt
return nil
}
// CreateAuctionsFromDeposit creates auctions from the input deposit until there is less than auctionSize left on the deposit
// CreateAuctionsFromDeposit creates auctions from the input deposit
func (k Keeper) CreateAuctionsFromDeposit(
ctx sdk.Context, dep types.Deposit, debt sdk.Int, totalCollateral sdk.Int, auctionSize sdk.Int,
principalDenom string) (debtChange sdk.Int, collateralChange sdk.Int, err error) {
debtChange = sdk.ZeroInt()
collateralChange = sdk.ZeroInt()
depositAmount := dep.Amount.Amount
depositDenom := dep.Amount.Denom
for depositAmount.GTE(auctionSize) {
// figure out how much debt is covered by one lots worth of collateral
depositDebtAmount := (sdk.NewDecFromInt(auctionSize).Quo(sdk.NewDecFromInt(totalCollateral))).Mul(sdk.NewDecFromInt(debt)).RoundInt()
penalty := k.ApplyLiquidationPenalty(ctx, depositDenom, depositDebtAmount)
// start an auction for one lot, attempting to raise depositDebtAmount plus the liquidation penalty
ctx sdk.Context, collateral sdk.Coin, returnAddr sdk.AccAddress, debt, auctionSize sdk.Int,
principalDenom string) (err error) {
amountToAuction := sdk.NewInt(collateral.Amount.Int64())
totalCollateralAmount := sdk.NewInt(collateral.Amount.Int64())
remainingDebt := sdk.NewInt(debt.Int64())
for amountToAuction.GT(sdk.ZeroInt()) {
for amountToAuction.GT(auctionSize) {
debtCoveredByAuction := (sdk.NewDecFromInt(auctionSize).Quo(sdk.NewDecFromInt(totalCollateralAmount))).Mul(sdk.NewDecFromInt(debt)).RoundInt()
penalty := k.ApplyLiquidationPenalty(ctx, collateral.Denom, debtCoveredByAuction)
_, err := k.auctionKeeper.StartCollateralAuction(
ctx, types.LiquidatorMacc, sdk.NewCoin(depositDenom, auctionSize), sdk.NewCoin(principalDenom, depositDebtAmount.Add(penalty)), []sdk.AccAddress{dep.Depositor},
[]sdk.Int{auctionSize}, sdk.NewCoin(k.GetDebtDenom(ctx), depositDebtAmount))
ctx, types.LiquidatorMacc, sdk.NewCoin(collateral.Denom, auctionSize), sdk.NewCoin(principalDenom, debtCoveredByAuction.Add(penalty)), []sdk.AccAddress{returnAddr},
[]sdk.Int{auctionSize}, sdk.NewCoin(k.GetDebtDenom(ctx), debtCoveredByAuction))
if err != nil {
return sdk.ZeroInt(), sdk.ZeroInt(), err
return err
}
depositAmount = depositAmount.Sub(auctionSize)
totalCollateral = totalCollateral.Sub(auctionSize)
debt = debt.Sub(depositDebtAmount)
// subtract one lot's worth of debt from the total debt covered by this deposit
debtChange = debtChange.Add(depositDebtAmount)
collateralChange = collateralChange.Add(auctionSize)
amountToAuction = amountToAuction.Sub(auctionSize)
remainingDebt = remainingDebt.Sub(debtCoveredByAuction)
}
return debtChange, collateralChange, nil
}
// CreateAuctionFromPartialDeposits creates an auction from the input partial deposits
func (k Keeper) CreateAuctionFromPartialDeposits(ctx sdk.Context, partialDeps partialDeposits, debt sdk.Int, collateral sdk.Int, auctionSize sdk.Int, bidDenom string) (debtChange, collateralChange sdk.Int, err error) {
returnAddrs := []sdk.AccAddress{}
returnWeights := []sdk.Int{}
depositDenom := partialDeps[0].Amount.Denom
for _, pd := range partialDeps {
returnAddrs = append(returnAddrs, pd.Depositor)
returnWeights = append(returnWeights, pd.DebtShare)
}
penalty := k.ApplyLiquidationPenalty(ctx, depositDenom, partialDeps.SumDebt())
_, err = k.auctionKeeper.StartCollateralAuction(ctx, types.LiquidatorMacc, sdk.NewCoin(partialDeps[0].Amount.Denom, auctionSize), sdk.NewCoin(bidDenom, partialDeps.SumDebt().Add(penalty)), returnAddrs, returnWeights, sdk.NewCoin(k.GetDebtDenom(ctx), partialDeps.SumDebt()))
penalty := k.ApplyLiquidationPenalty(ctx, collateral.Denom, remainingDebt)
_, err := k.auctionKeeper.StartCollateralAuction(
ctx, types.LiquidatorMacc, sdk.NewCoin(collateral.Denom, amountToAuction), sdk.NewCoin(principalDenom, remainingDebt.Add(penalty)), []sdk.AccAddress{returnAddr},
[]sdk.Int{amountToAuction}, sdk.NewCoin(k.GetDebtDenom(ctx), remainingDebt))
if err != nil {
return sdk.ZeroInt(), sdk.ZeroInt(), err
return err
}
debtChange = partialDeps.SumDebt()
collateralChange = partialDeps.SumCollateral()
return debtChange, collateralChange, nil
amountToAuction = sdk.ZeroInt()
}
return nil
}
// NetSurplusAndDebt burns surplus and debt coins equal to the minimum of surplus and debt balances held by the liquidator module account

View File

@ -32,7 +32,6 @@ func (k Keeper) SeizeCollateral(ctx sdk.Context, cdp types.CDP) error {
if err != nil {
return err
}
fmt.Printf("SeizeCollateral:liquidator: %s\n", k.supplyKeeper.GetModuleAccount(ctx, types.LiquidatorMacc))
// liquidate deposits and send collateral from cdp to liquidator
for _, dep := range deposits {
@ -50,7 +49,6 @@ func (k Keeper) SeizeCollateral(ctx sdk.Context, cdp types.CDP) error {
}
k.DeleteDeposit(ctx, dep.CdpID, dep.Depositor)
}
fmt.Printf("SeizeCollateral:liquidator: %s\n", k.supplyKeeper.GetModuleAccount(ctx, types.LiquidatorMacc))
err = k.AuctionCollateral(ctx, deposits, debt, cdp.Principal.Denom)
if err != nil {
return err

View File

@ -2,7 +2,6 @@ package keeper_test
import (
"errors"
"fmt"
"math/rand"
"testing"
"time"
@ -167,10 +166,6 @@ func (suite *SeizeTestSuite) TestSeizeCollateralMultiDeposit() {
p := cdp.Principal.Amount
cl := cdp.Collateral.Amount
tpb := suite.keeper.GetTotalPrincipal(suite.ctx, "xrp", "usdx")
fmt.Printf("%s\n", cdp)
fmt.Printf("%s\n", deposits)
fmt.Printf("cdpaccount: %s\n", suite.app.GetSupplyKeeper().GetModuleAccount(suite.ctx, types.ModuleName))
fmt.Printf("liquidator: %s\n", suite.app.GetSupplyKeeper().GetModuleAccount(suite.ctx, types.LiquidatorMacc))
err = suite.keeper.SeizeCollateral(suite.ctx, cdp)
suite.NoError(err)
tpa := suite.keeper.GetTotalPrincipal(suite.ctx, "xrp", "usdx")