0g-chain/x/cdp/keeper/seize.go
Kevin Davis 9b1bf55be7
R4R: Move liquidator functions to cdp module (#280)
* wip: tpyes and keeper methods

* wip: iterators

* wip: types and keeper methods

* wip: add msgs

* wip: client methods

* wip: rebase develop

* wip: types tests

* wip: keeper tests, small fixes

* wip: add cdp tests

* wip: deposit tests

* wip: keeper tests

* wip: tests and module methods

* feat: error when fetching expired price

* feat: conversion factor for external assets

* feat: debt floor for new cdps

* feat: save deposits on export genesis

* feat: ensure messages implement msg

* feat: index deposits by status

* fix: stray comment

* wip: address review comments

* address review comments

* wip: move liquidation to cdp module

* wip: handle liquidations directly

* wip: use new auction interface

* feat: auction collateral in cdp begin block

* feat: update param validation

* feat: surplus and debt auctions

* address review comments

* address review comments

* fix: auction multiple deposits

* clean up netting function
2020-01-15 15:19:33 +01:00

111 lines
4.4 KiB
Go

package keeper
import (
"fmt"
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/kava-labs/kava/x/cdp/types"
)
// SeizeCollateral liquidates the collateral in the input cdp.
// the following operations are performed:
// 1. updates the fees for the input cdp,
// 2. sends collateral for all deposits from the cdp module to the liquidator module,
// 3. moves debt coins from the cdp module to the liquidator module,
// 4. decrements the total amount of principal outstanding for that collateral type
// (this is the equivalent of saying that fees are no longer accumulated by a cdp once it
// gets liquidated)
func (k Keeper) SeizeCollateral(ctx sdk.Context, cdp types.CDP) sdk.Error {
// Calculate the previous collateral ratio
oldCollateralToDebtRatio := k.CalculateCollateralToDebtRatio(ctx, cdp.Collateral, cdp.Principal.Add(cdp.AccumulatedFees))
// Update fees
periods := sdk.NewInt(ctx.BlockTime().Unix()).Sub(sdk.NewInt(cdp.FeesUpdated.Unix()))
fees := k.CalculateFees(ctx, cdp.Principal.Add(cdp.AccumulatedFees), periods, cdp.Collateral[0].Denom)
cdp.AccumulatedFees = cdp.AccumulatedFees.Add(fees)
cdp.FeesUpdated = ctx.BlockTime()
// TODO implement liquidation penalty
// Move debt coins from cdp to liquidator account
deposits := k.GetDeposits(ctx, cdp.ID)
debt := sdk.ZeroInt()
for _, pc := range cdp.Principal {
debt = debt.Add(pc.Amount)
}
for _, dc := range cdp.AccumulatedFees {
debt = debt.Add(dc.Amount)
}
debtCoin := sdk.NewCoin(k.GetDebtDenom(ctx), debt)
err := k.supplyKeeper.SendCoinsFromModuleToModule(ctx, types.ModuleName, types.LiquidatorMacc, sdk.NewCoins(debtCoin))
if err != nil {
return err
}
// liquidate deposits and send collateral from cdp to liquidator
for _, dep := range deposits {
ctx.EventManager().EmitEvent(
sdk.NewEvent(
types.EventTypeCdpLiquidation,
sdk.NewAttribute(sdk.AttributeKeyModule, types.AttributeValueCategory),
sdk.NewAttribute(types.AttributeKeyCdpID, fmt.Sprintf("%d", cdp.ID)),
sdk.NewAttribute(types.AttributeKeyDepositor, fmt.Sprintf("%s", dep.Depositor)),
),
)
err := k.supplyKeeper.SendCoinsFromModuleToModule(ctx, types.ModuleName, types.LiquidatorMacc, dep.Amount)
if err != nil {
return err
}
k.DeleteDeposit(ctx, dep.CdpID, dep.Depositor)
}
err = k.AuctionCollateral(ctx, deposits, debt, cdp.Principal[0].Denom)
if err != nil {
return err
}
// Decrement total principal for this collateral type
for _, dc := range cdp.Principal {
feeAmount := cdp.AccumulatedFees.AmountOf(dc.Denom)
coinsToDecrement := sdk.NewCoins(dc)
if feeAmount.IsPositive() {
feeCoins := sdk.NewCoins(sdk.NewCoin(dc.Denom, feeAmount))
coinsToDecrement = coinsToDecrement.Add(feeCoins)
}
k.DecrementTotalPrincipal(ctx, cdp.Collateral[0].Denom, coinsToDecrement)
}
k.RemoveCdpOwnerIndex(ctx, cdp)
k.RemoveCdpCollateralRatioIndex(ctx, cdp.Collateral[0].Denom, cdp.ID, oldCollateralToDebtRatio)
k.DeleteCDP(ctx, cdp)
return nil
}
// HandleNewDebt compounds the accumulated fees for the input collateral and principal coins.
// the following operations are performed:
// 1. mints the fee coins in the liquidator module account,
// 2. mints the same amount of debt coins in the cdp module account
// 3. updates the total amount of principal for the input collateral type in the store,
func (k Keeper) HandleNewDebt(ctx sdk.Context, collateralDenom string, principalDenom string, periods sdk.Int) {
previousDebt := k.GetTotalPrincipal(ctx, collateralDenom, principalDenom)
feeCoins := sdk.NewCoins(sdk.NewCoin(principalDenom, previousDebt))
newFees := k.CalculateFees(ctx, feeCoins, periods, collateralDenom)
k.MintDebtCoins(ctx, types.ModuleName, k.GetDebtDenom(ctx), newFees)
k.supplyKeeper.MintCoins(ctx, types.LiquidatorMacc, newFees)
k.SetTotalPrincipal(ctx, collateralDenom, principalDenom, feeCoins.Add(newFees).AmountOf(principalDenom))
}
// LiquidateCdps seizes collateral from all CDPs below the input liquidation ratio
func (k Keeper) LiquidateCdps(ctx sdk.Context, marketID string, denom string, liquidationRatio sdk.Dec) sdk.Error {
price, err := k.pricefeedKeeper.GetCurrentPrice(ctx, marketID)
if err != nil {
return err
}
normalizedRatio := sdk.OneDec().Quo(price.Price.Quo(liquidationRatio))
cdpsToLiquidate := k.GetAllCdpsByDenomAndRatio(ctx, denom, normalizedRatio)
for _, c := range cdpsToLiquidate {
err := k.SeizeCollateral(ctx, c)
if err != nil {
return err
}
}
return nil
}