Pool Cleanup

x/gamm/keeper/pool.go

@@ -80,6 +80,109 @@ func (k Keeper) SetPool(ctx sdk.Context, pool types.PoolI) error {
 	return nil
 }
 
+func (k Keeper) DeletePool(ctx sdk.Context, poolId uint64) error {
+	store := ctx.KVStore(k.storeKey)
+	poolKey := types.GetKeyPrefixPools(poolId)
+	if !store.Has(poolKey) {
+		return fmt.Errorf("pool with ID %d does not exist", poolId)
+	}
+
+	store.Delete(poolKey)
+	return nil
+}
+
+// CleanupBalancerPool destructs a pool and refund all the assets according to
+// the shares held by the accounts. CleanupBalancerPool should not be called during
+// the chain execution time, as it iterates the entire account balances.
+// TODO: once SDK v0.46.0, use https://github.com/cosmos/cosmos-sdk/pull/9611
+//
+// All locks on this pool share must be unlocked prior to execution. Use LockupKeeper.ForceUnlock
+// on remaining locks before calling this function.
+func (k Keeper) CleanupBalancerPool(ctx sdk.Context, poolIds []uint64, excludedModules []string) (err error) {
+	pools := make(map[string]types.PoolI)
+	totalShares := make(map[string]sdk.Int)
+	for _, poolId := range poolIds {
+		pool, err := k.GetPool(ctx, poolId)
+		if err != nil {
+			return err
+		}
+		shareDenom := pool.GetTotalShares().Denom
+		pools[shareDenom] = pool
+		totalShares[shareDenom] = pool.GetTotalShares().Amount
+	}
+
+	moduleAccounts := make(map[string]string)
+	for _, module := range excludedModules {
+		moduleAccounts[string(authtypes.NewModuleAddress(module))] = module
+	}
+
+	// first iterate through the share holders and burn them
+	k.bankKeeper.IterateAllBalances(ctx, func(addr sdk.AccAddress, coin sdk.Coin) (stop bool) {
+		if coin.Amount.IsZero() {
+			return
+		}
+
+		pool, ok := pools[coin.Denom]
+		if !ok {
+			return
+		}
+
+		// track the iterated shares
+		pool.SubTotalShares(coin.Amount)
+		pools[coin.Denom] = pool
+
+		// check if the shareholder is a module
+		if _, ok = moduleAccounts[coin.Denom]; ok {
+			return
+		}
+
+		// Burn the share tokens
+		err = k.bankKeeper.SendCoinsFromAccountToModule(ctx, addr, types.ModuleName, sdk.Coins{coin})
+		if err != nil {
+			return true
+		}
+
+		err = k.bankKeeper.BurnCoins(ctx, types.ModuleName, sdk.Coins{coin})
+		if err != nil {
+			return true
+		}
+
+		// Refund assets
+		for _, asset := range pool.GetAllPoolAssets() {
+			// lpShareEquivalentTokens = (amount in pool) * (your shares) / (total shares)
+			lpShareEquivalentTokens := asset.Token.Amount.Mul(coin.Amount).Quo(totalShares[coin.Denom])
+			if lpShareEquivalentTokens.IsZero() {
+				continue
+			}
+			err = k.bankKeeper.SendCoins(
+				ctx, pool.GetAddress(), addr, sdk.Coins{{asset.Token.Denom, lpShareEquivalentTokens}})
+			if err != nil {
+				return true
+			}
+		}
+
+		return false
+	})
+
+	if err != nil {
+		return err
+	}
+
+	for _, pool := range pools {
+		// sanity check
+		if !pool.GetTotalShares().IsZero() {
+			panic("pool total share should be zero after cleanup")
+		}
+
+		err = k.DeletePool(ctx, pool.GetId())
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // newBalancerPool is an internal function that creates a new Balancer Pool object with the provided
 // parameters, initial assets, and future governor.
 func (k Keeper) newBalancerPool(ctx sdk.Context, balancerPoolParams balancer.BalancerPoolParams, assets []types.PoolAsset, futureGovernor string) (types.PoolI, error) {

x/gamm/keeper/pool_test.go

@@ -0,0 +1,222 @@
+package keeper_test
+
+import (
+	"math/rand"
+	"time"
+
+	"github.com/cosmos/cosmos-sdk/simapp"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/osmosis-labs/osmosis/x/gamm/types"
+)
+
+func (suite *KeeperTestSuite) TestCleanupPool() {
+	// Mint some assets to the accounts.
+	for _, acc := range []sdk.AccAddress{acc1, acc2, acc3} {
+		err := simapp.FundAccount(
+			suite.app.BankKeeper,
+			suite.ctx,
+			acc,
+			sdk.NewCoins(
+				sdk.NewCoin("uosmo", sdk.NewInt(1000000000)),
+				sdk.NewCoin("foo", sdk.NewInt(1000)),
+				sdk.NewCoin("bar", sdk.NewInt(1000)),
+				sdk.NewCoin("baz", sdk.NewInt(1000)),
+			),
+		)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	poolId, err := suite.app.GAMMKeeper.CreateBalancerPool(suite.ctx, acc1, defaultBalancerPoolParams, []types.PoolAsset{
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("foo", sdk.NewInt(1000)),
+		},
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("bar", sdk.NewInt(1000)),
+		},
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("baz", sdk.NewInt(1000)),
+		},
+	}, "")
+	suite.NoError(err)
+
+	for _, acc := range []sdk.AccAddress{acc2, acc3} {
+		err = suite.app.GAMMKeeper.JoinPool(suite.ctx, acc, poolId, types.OneShare.MulRaw(100), sdk.NewCoins(
+			sdk.NewCoin("foo", sdk.NewInt(1000)),
+			sdk.NewCoin("bar", sdk.NewInt(1000)),
+			sdk.NewCoin("baz", sdk.NewInt(1000)),
+		))
+		suite.NoError(err)
+	}
+
+	pool, err := suite.app.GAMMKeeper.GetPool(suite.ctx, poolId)
+	suite.NoError(err)
+	denom := pool.GetTotalShares().Denom
+	totalAmount := sdk.ZeroInt()
+	for _, acc := range []sdk.AccAddress{acc1, acc2, acc3} {
+		coin := suite.app.BankKeeper.GetBalance(suite.ctx, acc, denom)
+		suite.True(coin.Amount.Equal(types.OneShare.MulRaw(100)))
+		totalAmount = totalAmount.Add(coin.Amount)
+	}
+	suite.True(totalAmount.Equal(types.OneShare.MulRaw(300)))
+
+	err = suite.app.GAMMKeeper.CleanupBalancerPool(suite.ctx, []uint64{poolId}, []string{})
+	suite.NoError(err)
+	for _, acc := range []sdk.AccAddress{acc1, acc2, acc3} {
+		for _, denom := range []string{"foo", "bar", "baz"} {
+			amt := suite.app.BankKeeper.GetBalance(suite.ctx, acc, denom)
+			suite.True(amt.Amount.Equal(sdk.NewInt(1000)),
+				"Expected equal %s: %d, %d", amt.Denom, amt.Amount.Int64(), 1000)
+		}
+	}
+}
+
+func (suite *KeeperTestSuite) TestCleanupPoolRandomized() {
+	// address => deposited coins
+	coinOf := make(map[string]sdk.Coins)
+	denoms := []string{"foo", "bar", "baz"}
+
+	// Mint some assets to the accounts.
+	for _, acc := range []sdk.AccAddress{acc1, acc2, acc3} {
+		coins := make(sdk.Coins, 3)
+		for i := range coins {
+			amount := sdk.NewInt(rand.Int63n(1000))
+			// give large amount of coins to the pool creator
+			if i == 0 {
+				amount = amount.MulRaw(10000)
+			}
+			coins[i] = sdk.Coin{denoms[i], amount}
+		}
+		coinOf[acc.String()] = coins
+		coins = append(coins, sdk.NewCoin("uosmo", sdk.NewInt(1000000000)))
+
+		err := simapp.FundAccount(
+			suite.app.BankKeeper,
+			suite.ctx,
+			acc,
+			coins.Sort(),
+		)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	initialAssets := []types.PoolAsset{}
+	for _, coin := range coinOf[acc1.String()] {
+		initialAssets = append(initialAssets, types.PoolAsset{Weight: types.OneShare.MulRaw(100), Token: coin})
+	}
+	poolId, err := suite.app.GAMMKeeper.CreateBalancerPool(suite.ctx, acc1, defaultBalancerPoolParams, initialAssets, "")
+	suite.NoError(err)
+
+	for _, acc := range []sdk.AccAddress{acc2, acc3} {
+		err = suite.app.GAMMKeeper.JoinPool(suite.ctx, acc, poolId, types.OneShare, coinOf[acc.String()])
+		suite.NoError(err)
+	}
+
+	err = suite.app.GAMMKeeper.CleanupBalancerPool(suite.ctx, []uint64{poolId}, []string{})
+	suite.NoError(err)
+	for _, acc := range []sdk.AccAddress{acc1, acc2, acc3} {
+		for _, coin := range coinOf[acc.String()] {
+			amt := suite.app.BankKeeper.GetBalance(suite.ctx, acc, coin.Denom)
+			// the refund could have rounding error
+			suite.True(amt.Amount.Equal(coin.Amount) || amt.Amount.Equal(coin.Amount.SubRaw(1)),
+				"Expected equal %s: %d, %d", amt.Denom, amt.Amount.Int64(), coin.Amount.Int64())
+		}
+	}
+}
+
+func (suite *KeeperTestSuite) TestCleanupPoolErrorOnSwap() {
+	suite.ctx = suite.ctx.WithBlockTime(time.Unix(1000, 1000))
+	err := simapp.FundAccount(
+		suite.app.BankKeeper,
+		suite.ctx,
+		acc1,
+		sdk.NewCoins(
+			sdk.NewCoin("uosmo", sdk.NewInt(1000000000)),
+			sdk.NewCoin("foo", sdk.NewInt(1000)),
+			sdk.NewCoin("bar", sdk.NewInt(1000)),
+			sdk.NewCoin("baz", sdk.NewInt(1000)),
+		),
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	poolId, err := suite.app.GAMMKeeper.CreateBalancerPool(suite.ctx, acc1, defaultBalancerPoolParams, []types.PoolAsset{
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("foo", sdk.NewInt(1000)),
+		},
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("bar", sdk.NewInt(1000)),
+		},
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("baz", sdk.NewInt(1000)),
+		},
+	}, "")
+	suite.NoError(err)
+
+	err = suite.app.GAMMKeeper.CleanupBalancerPool(suite.ctx, []uint64{poolId}, []string{})
+	suite.NoError(err)
+
+	_, _, err = suite.app.GAMMKeeper.SwapExactAmountIn(suite.ctx, acc1, poolId, sdk.NewCoin("foo", sdk.NewInt(1)), "bar", sdk.NewInt(1))
+	suite.Error(err)
+}
+
+func (suite *KeeperTestSuite) TestCleanupPoolWithLockup() {
+	suite.ctx = suite.ctx.WithBlockTime(time.Unix(1000, 1000))
+	err := simapp.FundAccount(
+		suite.app.BankKeeper,
+		suite.ctx,
+		acc1,
+		sdk.NewCoins(
+			sdk.NewCoin("uosmo", sdk.NewInt(1000000000)),
+			sdk.NewCoin("foo", sdk.NewInt(1000)),
+			sdk.NewCoin("bar", sdk.NewInt(1000)),
+			sdk.NewCoin("baz", sdk.NewInt(1000)),
+		),
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	poolId, err := suite.app.GAMMKeeper.CreateBalancerPool(suite.ctx, acc1, defaultBalancerPoolParams, []types.PoolAsset{
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("foo", sdk.NewInt(1000)),
+		},
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("bar", sdk.NewInt(1000)),
+		},
+		{
+			Weight: sdk.NewInt(100),
+			Token:  sdk.NewCoin("baz", sdk.NewInt(1000)),
+		},
+	}, "")
+	suite.NoError(err)
+
+	_, err = suite.app.LockupKeeper.LockTokens(suite.ctx, acc1, sdk.Coins{sdk.NewCoin(types.GetPoolShareDenom(poolId), types.InitPoolSharesSupply)}, time.Hour)
+	suite.NoError(err)
+
+	for _, lock := range suite.app.LockupKeeper.GetLocksDenom(suite.ctx, types.GetPoolShareDenom(poolId)) {
+		err = suite.app.LockupKeeper.ForceUnlock(suite.ctx, lock)
+		suite.NoError(err)
+	}
+
+	err = suite.app.GAMMKeeper.CleanupBalancerPool(suite.ctx, []uint64{poolId}, []string{})
+	suite.NoError(err)
+	for _, coin := range []string{"foo", "bar", "baz"} {
+		amt := suite.app.BankKeeper.GetBalance(suite.ctx, acc1, coin)
+		// the refund could have rounding error
+		suite.True(amt.Amount.Equal(sdk.NewInt(1000)) || amt.Amount.Equal(sdk.NewInt(1000).SubRaw(1)),
+			"Expected equal %s: %d, %d", amt.Denom, amt.Amount.Int64(), sdk.NewInt(1000).Int64())
+	}
+}

x/gamm/types/errors.go

@@ -4,14 +4,15 @@ import sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 
 // x/gamm module sentinel errors
 var (
-	ErrPoolNotFound      = sdkerrors.Register(ModuleName, 1, "pool not found")
-	ErrPoolAlreadyExist  = sdkerrors.Register(ModuleName, 2, "pool already exist")
-	ErrPoolLocked        = sdkerrors.Register(ModuleName, 3, "pool is locked")
-	ErrTooFewPoolAssets  = sdkerrors.Register(ModuleName, 4, "pool should have at least 2 assets, as they must be swapping between at least two assets")
-	ErrTooManyPoolAssets = sdkerrors.Register(ModuleName, 5, "pool has too many assets (currently capped at 8 assets per pool)")
-	ErrLimitMaxAmount    = sdkerrors.Register(ModuleName, 6, "calculated amount is larger than max amount")
-	ErrLimitMinAmount    = sdkerrors.Register(ModuleName, 7, "calculated amount is lesser than min amount")
-	ErrInvalidMathApprox = sdkerrors.Register(ModuleName, 8, "invalid calculated result")
+	ErrPoolNotFound       = sdkerrors.Register(ModuleName, 1, "pool not found")
+	ErrPoolAlreadyExist   = sdkerrors.Register(ModuleName, 2, "pool already exist")
+	ErrPoolLocked         = sdkerrors.Register(ModuleName, 3, "pool is locked")
+	ErrTooFewPoolAssets   = sdkerrors.Register(ModuleName, 4, "pool should have at least 2 assets, as they must be swapping between at least two assets")
+	ErrTooManyPoolAssets  = sdkerrors.Register(ModuleName, 5, "pool has too many assets (currently capped at 8 assets per pool)")
+	ErrLimitMaxAmount     = sdkerrors.Register(ModuleName, 6, "calculated amount is larger than max amount")
+	ErrLimitMinAmount     = sdkerrors.Register(ModuleName, 7, "calculated amount is lesser than min amount")
+	ErrInvalidMathApprox  = sdkerrors.Register(ModuleName, 8, "invalid calculated result")
+	ErrAlreadyInvalidPool = sdkerrors.Register(ModuleName, 9, "destruction on already invalid pool")
 
 	ErrEmptyRoutes              = sdkerrors.Register(ModuleName, 21, "routes not defined")
 	ErrEmptyPoolAssets          = sdkerrors.Register(ModuleName, 22, "PoolAssets not defined")

x/gamm/types/expected_keepers.go

@@ -54,6 +54,7 @@ type BankKeeper interface {
 	GetSupply(ctx sdk.Context, denom string) sdk.Coin
 	UndelegateCoinsFromModuleToAccount(ctx sdk.Context, senderModule string, recipientAddr sdk.AccAddress, amt sdk.Coins) error
 	DelegateCoinsFromAccountToModule(ctx sdk.Context, senderAddr sdk.AccAddress, recipientModule string, amt sdk.Coins) error
+	IterateAllBalances(ctx sdk.Context, callback func(addr sdk.AccAddress, coin sdk.Coin) (stop bool))
 }
 
 // DistrKeeper defines the contract needed to be fulfilled for distribution keeper