Contract Name:
DiamondLoupeFacet
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/******************************************************************************\
* Author: Nick Mudge <[email protected]> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/
import { LibDiamond } from "../libraries/LibDiamond.sol";
import { IDiamondLoupe } from "../interfaces/IDiamondLoupe.sol";
import { IERC165 } from "../interfaces/IERC165.sol";
// The functions in DiamondLoupeFacet MUST be added to a diamond.
// The EIP-2535 Diamond standard requires these functions.
contract DiamondLoupeFacet is IDiamondLoupe, IERC165 {
// Diamond Loupe Functions
////////////////////////////////////////////////////////////////////
/// These functions are expected to be called frequently by tools.
//
// struct Facet {
// address facetAddress;
// bytes4[] functionSelectors;
// }
/// @notice Gets all facets and their selectors.
/// @return facets_ Facet
function facets() external override view returns (Facet[] memory facets_) {
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
uint256 numFacets = ds.facetAddresses.length;
facets_ = new Facet[](numFacets);
for (uint256 i; i < numFacets; i++) {
address facetAddress_ = ds.facetAddresses[i];
facets_[i].facetAddress = facetAddress_;
facets_[i].functionSelectors = ds.facetFunctionSelectors[facetAddress_].functionSelectors;
}
}
/// @notice Gets all the function selectors provided by a facet.
/// @param _facet The facet address.
/// @return facetFunctionSelectors_
function facetFunctionSelectors(address _facet) external override view returns (bytes4[] memory facetFunctionSelectors_) {
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
facetFunctionSelectors_ = ds.facetFunctionSelectors[_facet].functionSelectors;
}
/// @notice Get all the facet addresses used by a diamond.
/// @return facetAddresses_
function facetAddresses() external override view returns (address[] memory facetAddresses_) {
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
facetAddresses_ = ds.facetAddresses;
}
/// @notice Gets the facet that supports the given selector.
/// @dev If facet is not found return address(0).
/// @param _functionSelector The function selector.
/// @return facetAddress_ The facet address.
function facetAddress(bytes4 _functionSelector) external override view returns (address facetAddress_) {
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
facetAddress_ = ds.selectorToFacetAndPosition[_functionSelector].facetAddress;
}
// This implements ERC-165.
function supportsInterface(bytes4 _interfaceId) external override view returns (bool) {
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
return ds.supportedInterfaces[_interfaceId];
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/******************************************************************************\
* Author: Nick Mudge <[email protected]> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/
interface IDiamondCut {
enum FacetCutAction {Add, Replace, Remove}
// Add=0, Replace=1, Remove=2
struct FacetCut {
address facetAddress;
FacetCutAction action;
bytes4[] functionSelectors;
}
/// @notice Add/replace/remove any number of functions and optionally execute
/// a function with delegatecall
/// @param _diamondCut Contains the facet addresses and function selectors
/// @param _init The address of the contract or facet to execute _calldata
/// @param _calldata A function call, including function selector and arguments
/// _calldata is executed with delegatecall on _init
function diamondCut(
FacetCut[] calldata _diamondCut,
address _init,
bytes calldata _calldata
) external;
event DiamondCut(FacetCut[] _diamondCut, address _init, bytes _calldata);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/******************************************************************************\
* Author: Nick Mudge <[email protected]> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/
// A loupe is a small magnifying glass used to look at diamonds.
// These functions look at diamonds
interface IDiamondLoupe {
/// These functions are expected to be called frequently
/// by tools.
struct Facet {
address facetAddress;
bytes4[] functionSelectors;
}
/// @notice Gets all facet addresses and their four byte function selectors.
/// @return facets_ Facet
function facets() external view returns (Facet[] memory facets_);
/// @notice Gets all the function selectors supported by a specific facet.
/// @param _facet The facet address.
/// @return facetFunctionSelectors_
function facetFunctionSelectors(address _facet) external view returns (bytes4[] memory facetFunctionSelectors_);
/// @notice Get all the facet addresses used by a diamond.
/// @return facetAddresses_
function facetAddresses() external view returns (address[] memory facetAddresses_);
/// @notice Gets the facet that supports the given selector.
/// @dev If facet is not found return address(0).
/// @param _functionSelector The function selector.
/// @return facetAddress_ The facet address.
function facetAddress(bytes4 _functionSelector) external view returns (address facetAddress_);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface IERC165 {
/// @notice Query if a contract implements an interface
/// @param interfaceId The interface identifier, as specified in ERC-165
/// @dev Interface identification is specified in ERC-165. This function
/// uses less than 30,000 gas.
/// @return `true` if the contract implements `interfaceID` and
/// `interfaceID` is not 0xffffffff, `false` otherwise
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/******************************************************************************\
* Author: Nick Mudge <[email protected]> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/
import { IDiamondCut } from "../interfaces/IDiamondCut.sol";
// Remember to add the loupe functions from DiamondLoupeFacet to the diamond.
// The loupe functions are required by the EIP2535 Diamonds standard
error InitializationFunctionReverted(address _initializationContractAddress, bytes _calldata);
library LibDiamond {
bytes32 constant DIAMOND_STORAGE_POSITION = keccak256("diamond.standard.diamond.storage");
struct FacetAddressAndPosition {
address facetAddress;
uint96 functionSelectorPosition; // position in facetFunctionSelectors.functionSelectors array
}
struct FacetFunctionSelectors {
bytes4[] functionSelectors;
uint256 facetAddressPosition; // position of facetAddress in facetAddresses array
}
struct DiamondStorage {
// maps function selector to the facet address and
// the position of the selector in the facetFunctionSelectors.selectors array
mapping(bytes4 => FacetAddressAndPosition) selectorToFacetAndPosition;
// maps facet addresses to function selectors
mapping(address => FacetFunctionSelectors) facetFunctionSelectors;
// facet addresses
address[] facetAddresses;
// Used to query if a contract implements an interface.
// Used to implement ERC-165.
mapping(bytes4 => bool) supportedInterfaces;
// owner of the contract
address contractOwner;
}
function diamondStorage() internal pure returns (DiamondStorage storage ds) {
bytes32 position = DIAMOND_STORAGE_POSITION;
assembly {
ds.slot := position
}
}
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
function setContractOwner(address _newOwner) internal {
DiamondStorage storage ds = diamondStorage();
address previousOwner = ds.contractOwner;
ds.contractOwner = _newOwner;
emit OwnershipTransferred(previousOwner, _newOwner);
}
function contractOwner() internal view returns (address contractOwner_) {
contractOwner_ = diamondStorage().contractOwner;
}
function enforceIsContractOwner() internal view {
require(msg.sender == diamondStorage().contractOwner, "LibDiamond: Must be contract owner");
}
event DiamondCut(IDiamondCut.FacetCut[] _diamondCut, address _init, bytes _calldata);
// Internal function version of diamondCut
function diamondCut(
IDiamondCut.FacetCut[] memory _diamondCut,
address _init,
bytes memory _calldata
) internal {
for (uint256 facetIndex; facetIndex < _diamondCut.length; facetIndex++) {
IDiamondCut.FacetCutAction action = _diamondCut[facetIndex].action;
if (action == IDiamondCut.FacetCutAction.Add) {
addFunctions(_diamondCut[facetIndex].facetAddress, _diamondCut[facetIndex].functionSelectors);
} else if (action == IDiamondCut.FacetCutAction.Replace) {
replaceFunctions(_diamondCut[facetIndex].facetAddress, _diamondCut[facetIndex].functionSelectors);
} else if (action == IDiamondCut.FacetCutAction.Remove) {
removeFunctions(_diamondCut[facetIndex].facetAddress, _diamondCut[facetIndex].functionSelectors);
} else {
revert("LibDiamondCut: Incorrect FacetCutAction");
}
}
emit DiamondCut(_diamondCut, _init, _calldata);
initializeDiamondCut(_init, _calldata);
}
function addFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
require(_functionSelectors.length > 0, "LibDiamondCut: No selectors in facet to cut");
DiamondStorage storage ds = diamondStorage();
require(_facetAddress != address(0), "LibDiamondCut: Add facet can't be address(0)");
uint96 selectorPosition = uint96(ds.facetFunctionSelectors[_facetAddress].functionSelectors.length);
// add new facet address if it does not exist
if (selectorPosition == 0) {
addFacet(ds, _facetAddress);
}
for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
bytes4 selector = _functionSelectors[selectorIndex];
address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
require(oldFacetAddress == address(0), "LibDiamondCut: Can't add function that already exists");
addFunction(ds, selector, selectorPosition, _facetAddress);
selectorPosition++;
}
}
function replaceFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
require(_functionSelectors.length > 0, "LibDiamondCut: No selectors in facet to cut");
DiamondStorage storage ds = diamondStorage();
require(_facetAddress != address(0), "LibDiamondCut: Add facet can't be address(0)");
uint96 selectorPosition = uint96(ds.facetFunctionSelectors[_facetAddress].functionSelectors.length);
// add new facet address if it does not exist
if (selectorPosition == 0) {
addFacet(ds, _facetAddress);
}
for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
bytes4 selector = _functionSelectors[selectorIndex];
address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
require(oldFacetAddress != _facetAddress, "LibDiamondCut: Can't replace function with same function");
removeFunction(ds, oldFacetAddress, selector);
addFunction(ds, selector, selectorPosition, _facetAddress);
selectorPosition++;
}
}
function removeFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
require(_functionSelectors.length > 0, "LibDiamondCut: No selectors in facet to cut");
DiamondStorage storage ds = diamondStorage();
// if function does not exist then do nothing and return
require(_facetAddress == address(0), "LibDiamondCut: Remove facet address must be address(0)");
for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
bytes4 selector = _functionSelectors[selectorIndex];
address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
removeFunction(ds, oldFacetAddress, selector);
}
}
function addFacet(DiamondStorage storage ds, address _facetAddress) internal {
enforceHasContractCode(_facetAddress, "LibDiamondCut: New facet has no code");
ds.facetFunctionSelectors[_facetAddress].facetAddressPosition = ds.facetAddresses.length;
ds.facetAddresses.push(_facetAddress);
}
function addFunction(DiamondStorage storage ds, bytes4 _selector, uint96 _selectorPosition, address _facetAddress) internal {
ds.selectorToFacetAndPosition[_selector].functionSelectorPosition = _selectorPosition;
ds.facetFunctionSelectors[_facetAddress].functionSelectors.push(_selector);
ds.selectorToFacetAndPosition[_selector].facetAddress = _facetAddress;
}
function removeFunction(DiamondStorage storage ds, address _facetAddress, bytes4 _selector) internal {
require(_facetAddress != address(0), "LibDiamondCut: Can't remove function that doesn't exist");
// an immutable function is a function defined directly in a diamond
require(_facetAddress != address(this), "LibDiamondCut: Can't remove immutable function");
// replace selector with last selector, then delete last selector
uint256 selectorPosition = ds.selectorToFacetAndPosition[_selector].functionSelectorPosition;
uint256 lastSelectorPosition = ds.facetFunctionSelectors[_facetAddress].functionSelectors.length - 1;
// if not the same then replace _selector with lastSelector
if (selectorPosition != lastSelectorPosition) {
bytes4 lastSelector = ds.facetFunctionSelectors[_facetAddress].functionSelectors[lastSelectorPosition];
ds.facetFunctionSelectors[_facetAddress].functionSelectors[selectorPosition] = lastSelector;
ds.selectorToFacetAndPosition[lastSelector].functionSelectorPosition = uint96(selectorPosition);
}
// delete the last selector
ds.facetFunctionSelectors[_facetAddress].functionSelectors.pop();
delete ds.selectorToFacetAndPosition[_selector];
// if no more selectors for facet address then delete the facet address
if (lastSelectorPosition == 0) {
// replace facet address with last facet address and delete last facet address
uint256 lastFacetAddressPosition = ds.facetAddresses.length - 1;
uint256 facetAddressPosition = ds.facetFunctionSelectors[_facetAddress].facetAddressPosition;
if (facetAddressPosition != lastFacetAddressPosition) {
address lastFacetAddress = ds.facetAddresses[lastFacetAddressPosition];
ds.facetAddresses[facetAddressPosition] = lastFacetAddress;
ds.facetFunctionSelectors[lastFacetAddress].facetAddressPosition = facetAddressPosition;
}
ds.facetAddresses.pop();
delete ds.facetFunctionSelectors[_facetAddress].facetAddressPosition;
}
}
function initializeDiamondCut(address _init, bytes memory _calldata) internal {
if (_init == address(0)) {
return;
}
enforceHasContractCode(_init, "LibDiamondCut: _init address has no code");
(bool success, bytes memory error) = _init.delegatecall(_calldata);
if (!success) {
if (error.length > 0) {
// bubble up error
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(error)
revert(add(32, error), returndata_size)
}
} else {
revert InitializationFunctionReverted(_init, _calldata);
}
}
}
function enforceHasContractCode(address _contract, string memory _errorMessage) internal view {
uint256 contractSize;
assembly {
contractSize := extcodesize(_contract)
}
require(contractSize > 0, _errorMessage);
}
}