Supply by denom Migrations (cosmos#8780)

* Add back supply proto

* Add migration for supply

* Fix lint

* Update x/bank/spec/01_state.md

* Fix test

* Proto gen

* Update x/bank/spec/01_state.md

* Make proto gen

Co-authored-by: Jonathan Gimeno <jgimeno@gmail.com>

docs/core/proto-docs.md

@@ -80,6 +80,7 @@
     - [Output](#cosmos.bank.v1beta1.Output)
     - [Params](#cosmos.bank.v1beta1.Params)
     - [SendEnabled](#cosmos.bank.v1beta1.SendEnabled)
+    - [Supply](#cosmos.bank.v1beta1.Supply)
 
 - [cosmos/bank/v1beta1/genesis.proto](#cosmos/bank/v1beta1/genesis.proto)
     - [Balance](#cosmos.bank.v1beta1.Balance)
@@ -1560,6 +1561,23 @@ sendable).
 
 
 
+
+<a name="cosmos.bank.v1beta1.Supply"></a>
+
+### Supply
+Supply represents a struct that passively keeps track of the total supply
+amounts in the network.
+This message is deprecated now that supply is indexed by denom.
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| `total` | [cosmos.base.v1beta1.Coin](#cosmos.base.v1beta1.Coin) | repeated |  |
+
+
+
+
+
  <!-- end messages -->
 
  <!-- end enums -->

proto/cosmos/bank/v1beta1/bank.proto

@@ -43,6 +43,21 @@ message Output {
       [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];
 }
 
+// Supply represents a struct that passively keeps track of the total supply
+// amounts in the network.
+// This message is deprecated now that supply is indexed by denom.
+message Supply {
+  option deprecated = true;
+
+  option (gogoproto.equal)            = true;
+  option (gogoproto.goproto_getters)  = false;
+
+  option (cosmos_proto.implements_interface) = "*github.com/cosmos/cosmos-sdk/x/bank/exported.SupplyI";
+
+  repeated cosmos.base.v1beta1.Coin total = 1
+      [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];
+}
+
 // DenomUnit represents a struct that describes a given
 // denomination unit of the basic token.
 message DenomUnit {

x/bank/keeper/migrations.go

@@ -17,5 +17,5 @@ func NewMigrator(keeper BaseKeeper) Migrator {
 
 // Migrate1to2 migrates from version 1 to 2.
 func (m Migrator) Migrate1to2(ctx sdk.Context) error {
-	return v042.MigrateStore(ctx, m.keeper.storeKey)
+	return v042.MigrateStore(ctx, m.keeper.storeKey, m.keeper.cdc)
 }

x/bank/keeper/querier.go

@@ -84,7 +84,8 @@ func queryTotalSupply(ctx sdk.Context, req abci.RequestQuery, k Keeper, legacyQu
 		return nil, sdkerrors.Wrap(sdkerrors.ErrJSONUnmarshal, err.Error())
 	}
 
-	//TODO: pagenate
+	// TODO: paginate
+	// https://github.com/cosmos/cosmos-sdk/issues/8761
 	totalSupply := k.GetTotalSupply(ctx)
 
 	start, end := client.Paginate(len(totalSupply), params.Page, params.Limit, 100)

x/bank/legacy/v042/store.go

@@ -1,21 +1,46 @@
 package v042
 
 import (
+	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/store/prefix"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	v040auth "github.com/cosmos/cosmos-sdk/x/auth/legacy/v040"
 	v040bank "github.com/cosmos/cosmos-sdk/x/bank/legacy/v040"
 	"github.com/cosmos/cosmos-sdk/x/bank/types"
 )
 
-// MigrateStore performs in-place store migrations from v0.40 to v0.42. The
-// migration includes:
-//
-// - Change addresses to be length-prefixed.
-// - Change balances prefix to 1 byte
-func MigrateStore(ctx sdk.Context, storeKey sdk.StoreKey) error {
-	store := ctx.KVStore(storeKey)
+// migrateSupply migrates the supply to be stored by denom key instead in a
+// single blob.
+// ref: https://github.com/cosmos/cosmos-sdk/issues/7092
+func migrateSupply(store sdk.KVStore, cdc codec.BinaryMarshaler) error {
+	// Old supply was stored as a single blob under the SupplyKey.
+	var oldSupply types.Supply // nolint:staticcheck
+	err := cdc.UnmarshalBinaryBare(store.Get(v040bank.SupplyKey), &oldSupply)
+	if err != nil {
+		return err
+	}
+
+	// We delete the single key holding the whole blob.
+	store.Delete(v040bank.SupplyKey)
+
+	// We add a new key for each denom
+	supplyStore := prefix.NewStore(store, types.SupplyKey)
+	for i := range oldSupply.Total {
+		coin := oldSupply.Total[i]
+		coinBz, err := cdc.MarshalBinaryBare(&coin)
+		if err != nil {
+			return err
+		}
 
+		supplyStore.Set([]byte(coin.Denom), coinBz)
+	}
+
+	return nil
+}
+
+// migrateBalanceKeys migrate the balances keys to cater for variable-length
+// addresses.
+func migrateBalanceKeys(store sdk.KVStore) {
 	// old key is of format:
 	// prefix ("balances") || addrBytes (20 bytes) || denomBytes
 	// new key is of format
@@ -34,6 +59,17 @@ func MigrateStore(ctx sdk.Context, storeKey sdk.StoreKey) error {
 		store.Set(newStoreKey, oldStoreIter.Value())
 		oldStore.Delete(oldStoreIter.Key())
 	}
+}
 
-	return nil
+// MigrateStore performs in-place store migrations from v0.40 to v0.42. The
+// migration includes:
+//
+// - Change addresses to be length-prefixed.
+// - Change balances prefix to 1 byte
+// - Change supply to be indexed by denom
+func MigrateStore(ctx sdk.Context, storeKey sdk.StoreKey, cdc codec.BinaryMarshaler) error {
+	store := ctx.KVStore(storeKey)
+
+	migrateBalanceKeys(store)
+	return migrateSupply(store, cdc)
 }

x/bank/legacy/v042/store_test.go

@@ -5,6 +5,8 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/cosmos/cosmos-sdk/simapp"
+	"github.com/cosmos/cosmos-sdk/store/prefix"
 	"github.com/cosmos/cosmos-sdk/testutil"
 	"github.com/cosmos/cosmos-sdk/testutil/testdata"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -13,7 +15,35 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/bank/types"
 )
 
-func TestStoreMigration(t *testing.T) {
+func TestSupplyMigration(t *testing.T) {
+	encCfg := simapp.MakeTestEncodingConfig()
+	bankKey := sdk.NewKVStoreKey("bank")
+	ctx := testutil.DefaultContext(bankKey, sdk.NewTransientStoreKey("transient_test"))
+	store := ctx.KVStore(bankKey)
+
+	oldFooCoin := sdk.NewCoin("foo", sdk.NewInt(100))
+	oldBarCoin := sdk.NewCoin("bar", sdk.NewInt(200))
+
+	// Old supply was stored as a single blob under the `SupplyKey`.
+	oldSupply := types.Supply{Total: sdk.NewCoins(oldFooCoin, oldBarCoin)}
+	store.Set(v040bank.SupplyKey, encCfg.Marshaler.MustMarshalBinaryBare(&oldSupply))
+
+	// Run migration.
+	err := v042bank.MigrateStore(ctx, bankKey, encCfg.Marshaler)
+	require.NoError(t, err)
+
+	// New supply is indexed by denom.
+	var newFooCoin, newBarCoin sdk.Coin
+	supplyStore := prefix.NewStore(store, types.SupplyKey)
+	encCfg.Marshaler.MustUnmarshalBinaryBare(supplyStore.Get([]byte("foo")), &newFooCoin)
+	encCfg.Marshaler.MustUnmarshalBinaryBare(supplyStore.Get([]byte("bar")), &newBarCoin)
+
+	require.Equal(t, oldFooCoin, newFooCoin)
+	require.Equal(t, oldBarCoin, newBarCoin)
+}
+
+func TestBalanceKeysMigration(t *testing.T) {
+	encCfg := simapp.MakeTestEncodingConfig()
 	bankKey := sdk.NewKVStoreKey("bank")
 	ctx := testutil.DefaultContext(bankKey, sdk.NewTransientStoreKey("transient_test"))
 	store := ctx.KVStore(bankKey)
@@ -25,7 +55,7 @@ func TestStoreMigration(t *testing.T) {
 	oldKey := append(append(v040bank.BalancesPrefix, addr...), denom...)
 	store.Set(oldKey, value)
 
-	err := v042bank.MigrateStore(ctx, bankKey)
+	err := v042bank.MigrateStore(ctx, bankKey, encCfg.Marshaler)
 	require.NoError(t, err)
 
 	newKey := append(types.CreateAccountBalancesPrefix(addr), denom...)

x/bank/spec/01_state.md

@@ -4,8 +4,9 @@ order: 1
 
 # State
 
-The `x/bank` module keeps state of two primary objects, account balances and the
+The `x/bank` module keeps state of three primary objects, account balances, denom metadata and the
 total supply of all balances.
 
-- Supply: `0x0 -> ProtocolBuffer(Supply)`
+- Supply: `0x0 | byte(denom) -> ProtocolBuffer(coin)`
+- Denom Metadata: `0x1 | byte(denom) -> ProtocolBuffer(Metadata)`
 - Balances: `0x2 | byte(address length) | []byte(address) | []byte(balance.Denom) -> ProtocolBuffer(balance)`