Add reserved space for future upgrade

axieinfinity · Nov 4, 2022 · 603d7f6 · 603d7f6
1 parent 4ea5137
commit 603d7f6
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diff --git a/contracts/ronin/staking/RewardCalculation.sol b/contracts/ronin/staking/RewardCalculation.sol
@@ -17,6 +17,12 @@ abstract contract RewardCalculation is IRewardPool {
   /// @dev Mapping from the pool address => reward pool fields
   mapping(address => PoolFields) private _stakingPool;
 
+  /**
+   * @dev This empty reserved space is put in place to allow future versions to add new
+   * variables without shifting down storage in the inheritance chain.
+   */
+  uint256[50] private ______gap;
+
   /**
    * @inheritdoc IRewardPool
    */

diff --git a/contracts/ronin/staking/StakingManager.sol b/contracts/ronin/staking/StakingManager.sol
@@ -19,6 +19,12 @@ abstract contract StakingManager is
   /// @dev Mapping from pool address => staking pool detail
   mapping(address => PoolDetail) internal _stakingPool;
 
+  /**
+   * @dev This empty reserved space is put in place to allow future versions to add new
+   * variables without shifting down storage in the inheritance chain.
+   */
+  uint256[50] private ______gap;
+
   modifier noEmptyValue() {
     require(msg.value > 0, "StakingManager: query with empty value");
     _;