fix gas cost of insert header (#309)

* fix gas cost of insert header

app/app.go

@@ -298,7 +298,8 @@ func NewBabylonApp(
 		ibctransfertypes.StoreKey,
 		zctypes.StoreKey,
 	)
-	tkeys := sdk.NewTransientStoreKeys(paramstypes.TStoreKey)
+	tkeys := sdk.NewTransientStoreKeys(
+		paramstypes.TStoreKey, btccheckpointtypes.TStoreKey)
 	// NOTE: The testingkey is just mounted for testing purposes. Actual applications should
 	// not include this key.
 	memKeys := sdk.NewMemoryStoreKeys(capabilitytypes.MemStoreKey, "testingkey")
@@ -518,6 +519,7 @@ func NewBabylonApp(
 		btccheckpointkeeper.NewKeeper(
 			appCodec,
 			keys[btccheckpointtypes.StoreKey],
+			tkeys[btccheckpointtypes.TStoreKey],
 			keys[btccheckpointtypes.MemStoreKey],
 			app.GetSubspace(btccheckpointtypes.ModuleName),
 			&btclightclientKeeper,

testutil/keeper/btccheckpoint.go

@@ -26,6 +26,7 @@ func NewBTCCheckpointKeeper(
 	ek btcctypes.CheckpointingKeeper,
 	powLimit *big.Int) (*keeper.Keeper, sdk.Context) {
 	storeKey := sdk.NewKVStoreKey(btcctypes.StoreKey)
+	tstoreKey := sdk.NewTransientStoreKey(btcctypes.TStoreKey)
 	memStoreKey := storetypes.NewMemoryStoreKey(btcctypes.MemStoreKey)
 
 	db := tmdb.NewMemDB()
@@ -47,6 +48,7 @@ func NewBTCCheckpointKeeper(
 	k := keeper.NewKeeper(
 		cdc,
 		storeKey,
+		tstoreKey,
 		memStoreKey,
 		paramsSubspace,
 		lk,

x/btccheckpoint/abci.go

@@ -0,0 +1,16 @@
+package btccheckpoint
+
+import (
+	"github.com/babylonchain/babylon/x/btccheckpoint/keeper"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	abci "github.com/tendermint/tendermint/abci/types"
+)
+
+// EndBlocker checks if during block execution btc light client head had been
+// updated. If the head had been updated, status of all available checkpoints
+// is checked to determine if any of them became confirmed/finalized/abandonded.
+func EndBlocker(ctx sdk.Context, k keeper.Keeper, req abci.RequestEndBlock) {
+	if k.BtcLightClientUpdated(ctx) {
+		k.OnTipChange(ctx)
+	}
+}

x/btccheckpoint/keeper/hooks.go

@@ -21,11 +21,11 @@ var _ HandledHooks = Hooks{}
 func (k Keeper) Hooks() Hooks { return Hooks{k} }
 
 func (h Hooks) AfterBTCRollBack(ctx sdk.Context, headerInfo *ltypes.BTCHeaderInfo) {
-	h.k.OnTipChange(ctx)
+	h.k.setBtcLightClientUpdated(ctx)
 }
 
 func (h Hooks) AfterBTCRollForward(ctx sdk.Context, headerInfo *ltypes.BTCHeaderInfo) {
-	h.k.OnTipChange(ctx)
+	h.k.setBtcLightClientUpdated(ctx)
 }
 
 func (h Hooks) AfterBTCHeaderInserted(ctx sdk.Context, headerInfo *ltypes.BTCHeaderInfo) {}

x/btccheckpoint/keeper/keeper.go

@@ -20,6 +20,7 @@ type (
 	Keeper struct {
 		cdc                   codec.BinaryCodec
 		storeKey              storetypes.StoreKey
+		tstoreKey             storetypes.StoreKey
 		memKey                storetypes.StoreKey
 		paramstore            paramtypes.Subspace
 		btcLightClientKeeper  types.BTCLightClientKeeper
@@ -60,6 +61,7 @@ const (
 func NewKeeper(
 	cdc codec.BinaryCodec,
 	storeKey,
+	tstoreKey,
 	memKey storetypes.StoreKey,
 	ps paramtypes.Subspace,
 	bk types.BTCLightClientKeeper,
@@ -75,6 +77,7 @@ func NewKeeper(
 	return Keeper{
 		cdc:                   cdc,
 		storeKey:              storeKey,
+		tstoreKey:             tstoreKey,
 		memKey:                memKey,
 		paramstore:            ps,
 		btcLightClientKeeper:  bk,
@@ -347,6 +350,21 @@ func (k Keeper) OnTipChange(ctx sdk.Context) {
 	k.checkCheckpoints(ctx)
 }
 
+func (k Keeper) setBtcLightClientUpdated(ctx sdk.Context) {
+	store := ctx.TransientStore(k.tstoreKey)
+	store.Set(types.GetBtcLightClientUpdatedKey(), []byte{1})
+}
+
+// BtcLightClientUpdated checks if btc light client was updated during block execution
+func (k Keeper) BtcLightClientUpdated(ctx sdk.Context) bool {
+	// transient store is cleared after each block execution, therfore if
+	// BtcLightClientKey is set, it means setBtcLightClientUpdated was called during
+	// current block execution
+	store := ctx.TransientStore(k.tstoreKey)
+	lcUpdated := store.Get(types.GetBtcLightClientUpdatedKey())
+	return len(lcUpdated) > 0
+}
+
 func (k Keeper) getLastFinalizedEpochNumber(ctx sdk.Context) uint64 {
 	store := ctx.KVStore(k.storeKey)
 	epoch := store.Get(types.GetLatestFinalizedEpochKey())

x/btccheckpoint/module.go

@@ -172,6 +172,7 @@ func (am AppModule) BeginBlock(_ sdk.Context, _ abci.RequestBeginBlock) {}
 
 // EndBlock executes all ABCI EndBlock logic respective to the capability module. It
 // returns no validator updates.
-func (am AppModule) EndBlock(_ sdk.Context, _ abci.RequestEndBlock) []abci.ValidatorUpdate {
+func (am AppModule) EndBlock(ctx sdk.Context, req abci.RequestEndBlock) []abci.ValidatorUpdate {
+	EndBlocker(ctx, am.keeper, req)
 	return []abci.ValidatorUpdate{}
 }

x/btccheckpoint/types/keys.go

@@ -18,16 +18,21 @@ const (
 	// QuerierRoute defines the module's query routing key
 	QuerierRoute = ModuleName
 
+	TStoreKey = "transient_btccheckpoint"
+
 	// MemStoreKey defines the in-memory store key
 	MemStoreKey = "mem_btccheckpoint"
 
 	LatestFinalizedEpochKey = "latestFinalizedEpoch"
+
+	btcLightClientUpdated = "btcLightClientUpdated"
 )
 
 var (
-	SubmisionKeyPrefix    = []byte{3}
-	EpochDataPrefix       = []byte{4}
-	LastFinalizedEpochKey = append([]byte{5}, []byte(LatestFinalizedEpochKey)...)
+	SubmisionKeyPrefix       = []byte{3}
+	EpochDataPrefix          = []byte{4}
+	LastFinalizedEpochKey    = append([]byte{5}, []byte(LatestFinalizedEpochKey)...)
+	BtcLightClientUpdatedKey = append([]byte{6}, []byte(btcLightClientUpdated)...)
 )
 
 func KeyPrefix(p string) []byte {
@@ -45,3 +50,7 @@ func GetEpochIndexKey(e uint64) []byte {
 func GetLatestFinalizedEpochKey() []byte {
 	return LastFinalizedEpochKey
 }
+
+func GetBtcLightClientUpdatedKey() []byte {
+	return BtcLightClientUpdatedKey
+}