optimize Git3HubStorage

contracts/Git3Hub.sol

@@ -5,23 +5,7 @@ pragma solidity ^0.8.0;
 // import "@openzeppelin/contracts/access/Ownable.sol";
 import "./v2/LargeStorageManagerV2.sol";
 
-contract Git3HubStorage {
-    struct refInfo {
-        bytes20 hash;
-        uint96 index;
-    }
-
-    struct refData {
-        bytes20 hash;
-        bytes name;
-    }
-
-    mapping(bytes => address) public repoNameToOwner;
-    mapping(bytes => refInfo) public nameToRefInfo; // dev => {hash: 0x1234..., index: 1 }
-    mapping(bytes => bytes[]) public repoNameToRefs; // [main, dev, test, staging]
-}
-
-contract Git3Hub is Git3HubStorage, LargeStorageManagerV2 {
+contract Git3Hub is LargeStorageManagerV2 {
     event RepoCreated(bytes repoName, address owner);
     event RepoOwnerTransfer(bytes repoName, address oldOwner, address newOwner);
     event PushRef(bytes repoName, bytes ref);

contracts/Git3HubStorage.sol

@@ -0,0 +1,23 @@
+//SPDX-License-Identifier: Unlicense
+pragma solidity ^0.8.0;
+
+contract Git3HubStorage {
+    struct refInfo {
+        bytes20 hash;
+        uint96 index;
+    }
+
+    struct refData {
+        bytes20 hash;
+        bytes name;
+    }
+    // LargeStorageManagerV2 Storage Layout
+    mapping(bytes32 => mapping(uint256 => bytes32)) internal keyToMetadata;
+    mapping(bytes32 => mapping(uint256 => mapping(uint256 => bytes32)))
+        internal keyToSlots;  
+
+    // Git3Hub Storage Layout
+    mapping(bytes => address) public repoNameToOwner;
+    mapping(bytes => refInfo) public nameToRefInfo; // dev => {hash: 0x1234..., index: 1 }
+    mapping(bytes => bytes[]) public repoNameToRefs; // [main, dev, test, staging]
+}

contracts/v2/LargeStorageManagerV2.sol

@@ -4,19 +4,16 @@ pragma solidity ^0.8.0;
 import "./optimize/SlotHelper.sol";
 import "./StorageHelperV2.sol";
 import "./StorageSlotSelfDestructableV2.sol";
+import "../Git3HubStorage.sol";
 
 // Large storage manager to support arbitrarily-sized data with multiple chunk
-contract LargeStorageManagerV2 {
+contract LargeStorageManagerV2 is Git3HubStorage {
     using SlotHelper for bytes32;
     using SlotHelper for address;
 
     uint8 internal constant SLOT_LIMIT = 0;                                                                                                                                                         
 
-    mapping(bytes32 => mapping(uint256 => bytes32)) internal keyToMetadata;
-    mapping(bytes32 => mapping(uint256 => mapping(uint256 => bytes32)))
-        internal keyToSlots;
-
-    function isOptimize() public view returns (bool) {
+    function isOptimize() public pure returns (bool) {
         return SLOT_LIMIT > 0;
     }