added extended interface

src/MeijiMasterChefExtended.sol

@@ -0,0 +1,44 @@
+pragma solidity ^0.8.14;
+
+import "./MeijiMasterChef.sol";
+
+// Functions which would otherwise Clutter Masterchef for multi-actions
+contract MeijiMasterChefExtended is MeijiMasterChef {
+    function multiWithdraw(uint256[] calldata positionIds, uint256[] calldata amounts) external {
+        // Update summations only once.
+        _updateRewardSummations();
+
+        // Ensure array lengths match.
+        uint256 length = positionIds.length;
+        if (length != amounts.length) revert MismatchedArrayLengths();
+
+        for (uint256 i = 0; i < length; ) {
+            _withdraw(positionIds[i], amounts[i]);
+
+            // Counter realistically cannot overflow.
+            unchecked {
+                ++i;
+            }
+        }
+    }
+
+    function multiStake(uint256[] calldata positionIds, uint256[] calldata amounts) external {
+        // Update summations only once. Note that rewards accumulated when there is no one
+        // staking will be lost. But this is only a small risk of value loss if a reward period
+        // during no one staking is followed by staking.
+        _updateRewardSummations();
+
+        // Ensure array lengths match.
+        uint256 length = positionIds.length;
+        if (length != amounts.length) revert MismatchedArrayLengths();
+
+        for (uint256 i = 0; i < length; ) {
+            _stake(positionIds[i], amounts[i]);
+
+            // Counter realistically cannot overflow.
+            unchecked {
+                ++i;
+            }
+        }
+    }
+}