Merge pull request #94 from meTokens/diamond

refactor: diamond storage

contracts/Diamond.sol

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/******************************************************************************\
+* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
+* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
+*
+* Implementation of a diamond.
+/******************************************************************************/
+
+import {LibDiamond} from "./libs/LibDiamond.sol";
+import {IDiamondCut} from "./interfaces/IDiamondCut.sol";
+import {LibAppStorage} from "./libs/Details.sol";
+
+contract Diamond {
+    constructor(address _firstController, address _diamondCutFacet) payable {
+        LibAppStorage.initControllers(_firstController);
+
+        // Add the diamondCut external function from the diamondCutFacet
+        IDiamondCut.FacetCut[] memory cut = new IDiamondCut.FacetCut[](1);
+        bytes4[] memory functionSelectors = new bytes4[](1);
+        functionSelectors[0] = IDiamondCut.diamondCut.selector;
+        cut[0] = IDiamondCut.FacetCut({
+            facetAddress: _diamondCutFacet,
+            action: IDiamondCut.FacetCutAction.Add,
+            functionSelectors: functionSelectors
+        });
+        LibDiamond.diamondCut(cut, address(0), "");
+    }
+
+    receive() external payable {}
+
+    // Find facet for function that is called and execute the
+    // function if a facet is found and return any value.
+    /* solhint-disable */
+    fallback() external payable {
+        LibDiamond.DiamondStorage storage ds;
+        bytes32 position = LibDiamond.DIAMOND_STORAGE_POSITION;
+        // get diamond storage
+        assembly {
+            ds.slot := position
+        }
+        // get facet from function selector
+        address facet = ds.selectorToFacetAndPosition[msg.sig].facetAddress;
+        require(facet != address(0), "Diamond: Function does not exist");
+        // Execute external function from facet using delegatecall and return any value.
+        assembly {
+            // copy function selector and any arguments
+            calldatacopy(0, 0, calldatasize())
+            // execute function call using the facet
+            let result := delegatecall(gas(), facet, 0, calldatasize(), 0, 0)
+            // get any return value
+            returndatacopy(0, 0, returndatasize())
+            // return any return value or error back to the caller
+            switch result
+            case 0 {
+                revert(0, returndatasize())
+            }
+            default {
+                return(0, returndatasize())
+            }
+        }
+    }
+}

contracts/DiamondInit.sol

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import {IERC165} from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
+import {IERC173} from "./interfaces/IERC173.sol";
+import {IRegistry} from "./interfaces/IRegistry.sol";
+import {IMigrationRegistry} from "./interfaces/IMigrationRegistry.sol";
+import {IDiamondCut} from "./interfaces/IDiamondCut.sol";
+import {IDiamondLoupe} from "./interfaces/IDiamondLoupe.sol";
+import {LibDiamond} from "./libs/LibDiamond.sol";
+import "./libs/Details.sol";
+
+contract DiamondInit {
+    struct Args {
+        uint256 mintFee;
+        uint256 burnBuyerFee;
+        uint256 burnOwnerFee;
+        uint256 transferFee;
+        uint256 interestFee;
+        uint256 yieldFee;
+        address diamond;
+        IRegistry vaultRegistry;
+        IRegistry curveRegistry;
+        IMigrationRegistry migrationRegistry;
+        address meTokenFactory;
+    }
+
+    AppStorage internal s; // solhint-disable-line
+
+    // TODO: access control?
+    function init(Args memory _args) external {
+        s.diamond = _args.diamond;
+        s.vaultRegistry = _args.vaultRegistry;
+        s.curveRegistry = _args.curveRegistry;
+        s.migrationRegistry = _args.migrationRegistry;
+        s.meTokenFactory = _args.meTokenFactory;
+        s.mintFee = _args.mintFee;
+        s.burnBuyerFee = _args.burnBuyerFee;
+        s.burnOwnerFee = _args.burnOwnerFee;
+        s.transferFee = _args.transferFee;
+        s.interestFee = _args.interestFee;
+        s.yieldFee = _args.yieldFee;
+
+        s.MAX_REFUND_RATIO = 1e6;
+        s.PRECISION = 1e18;
+
+        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
+
+        // Adding erc165 data
+        ds.supportedInterfaces[type(IDiamondCut).interfaceId] = true;
+        ds.supportedInterfaces[type(IDiamondLoupe).interfaceId] = true;
+        ds.supportedInterfaces[type(IERC165).interfaceId] = true;
+        ds.supportedInterfaces[type(IERC173).interfaceId] = true;
+    }
+}