add staking middleware module

proto/centauri/stakingmiddleware/v1beta1/genesis.proto

@@ -0,0 +1,16 @@
+syntax = "proto3";
+package centauri.stakingmiddleware.v1beta1;
+
+import "gogoproto/gogo.proto";
+
+option go_package = "x/stakingmiddleware/types";
+
+// GenesisState defines the stakingmiddleware module's genesis state.
+message GenesisState {
+  // last_total_power tracks the total amounts of bonded tokens recorded during
+  // the previous end block.
+  bytes last_total_power = 1 [
+    (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Int",
+    (gogoproto.nullable)   = false
+  ];
+}

x/stakingmiddleware/types/keys.go

@@ -0,0 +1,29 @@
+package types
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/address"
+)
+
+// MinterKey is the key to use for the keeper store.
+var (
+	DelegationKey = []byte{0x01} // key for a delegation
+)
+
+const (
+	// module name
+	ModuleName = "mint"
+
+	// StoreKey is the default store key for mint
+	StoreKey = ModuleName
+)
+
+// GetDelegationKey creates the key for delegator bond with validator
+// VALUE: staking/Delegation
+func GetDelegationKey(delAddr sdk.AccAddress, valAddr sdk.ValAddress) []byte {
+	return append(GetDelegationsKey(delAddr), address.MustLengthPrefix(valAddr)...)
+}
+
+func GetDelegationsKey(delAddr sdk.AccAddress) []byte {
+	return append(DelegationKey, address.MustLengthPrefix(delAddr)...)
+}