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Contract Source Code:
File 1 of 1 : OwnedUpgradeabilityProxy
pragma solidity ^0.5.0; /** * @title Proxy * @dev Gives the possibility to delegate any call to a foreign implementation. */ contract Proxy { /** * @dev Fallback function allowing to perform a delegatecall to the given implementation. * This function will return whatever the implementation call returns */ function () external payable { address _impl = implementation(); require(_impl != address(0)); assembly { let ptr := mload(0x40) calldatacopy(ptr, 0, calldatasize) let result := delegatecall(gas, _impl, ptr, calldatasize, 0, 0) let size := returndatasize returndatacopy(ptr, 0, size) switch result case 0 { revert(ptr, size) } default { return(ptr, size) } } } /** * @dev Tells the address of the implementation where every call will be delegated. * @return address of the implementation to which it will be delegated */ function implementation() public view returns (address); } /** * @title UpgradeabilityProxy * @dev This contract represents a proxy where the implementation address to which it will delegate can be upgraded */ contract UpgradeabilityProxy is Proxy { /** * @dev This event will be emitted every time the implementation gets upgraded * @param implementation representing the address of the upgraded implementation */ event Upgraded(address indexed implementation); // Storage position of the address of the current implementation bytes32 private constant IMPLEMENTATION_POSITION = keccak256("offchain.proxy.implementation"); /** * @dev Constructor function */ constructor() public {} /** * @dev Tells the address of the current implementation * @return address of the current implementation */ function implementation() public view returns (address impl) { bytes32 position = IMPLEMENTATION_POSITION; assembly { impl := sload(position) } } /** * @dev Sets the address of the current implementation * @param _newImplementation address representing the new implementation to be set */ function _setImplementation(address _newImplementation) internal { bytes32 position = IMPLEMENTATION_POSITION; assembly { sstore(position, _newImplementation) } } /** * @dev Upgrades the implementation address * @param _newImplementation representing the address of the new implementation to be set */ function _upgradeTo(address _newImplementation) internal { address currentImplementation = implementation(); require(currentImplementation != _newImplementation); _setImplementation(_newImplementation); emit Upgraded(_newImplementation); } } /** * @title OwnedUpgradeabilityProxy * @dev This contract combines an upgradeability proxy with basic authorization control functionalities */ contract OwnedUpgradeabilityProxy is UpgradeabilityProxy { /** * @dev Event to show ownership has been transferred * @param previousOwner representing the address of the previous owner * @param newOwner representing the address of the new owner */ event ProxyOwnershipTransferred(address previousOwner, address newOwner); // Storage position of the owner of the contract bytes32 private constant PROXY_OWNER_POSITION = keccak256("offchain.proxy.owner"); /** * @dev the constructor sets the original owner of the contract to the sender account. */ constructor(address _implementation) public { _setUpgradeabilityOwner(msg.sender); _upgradeTo(_implementation); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyProxyOwner() { require(msg.sender == proxyOwner()); _; } /** * @dev Tells the address of the owner * @return the address of the owner */ function proxyOwner() public view returns (address owner) { bytes32 position = PROXY_OWNER_POSITION; assembly { owner := sload(position) } } /** * @dev Allows the current owner to transfer control of the contract to a newOwner. * @param _newOwner The address to transfer ownership to. */ function transferProxyOwnership(address _newOwner) public onlyProxyOwner { require(_newOwner != address(0)); _setUpgradeabilityOwner(_newOwner); emit ProxyOwnershipTransferred(proxyOwner(), _newOwner); } /** * @dev Allows the proxy owner to upgrade the current version of the proxy. * @param _implementation representing the address of the new implementation to be set. */ function upgradeTo(address _implementation) public onlyProxyOwner { _upgradeTo(_implementation); } /** * @dev Sets the address of the owner */ function _setUpgradeabilityOwner(address _newProxyOwner) internal { bytes32 position = PROXY_OWNER_POSITION; assembly { sstore(position, _newProxyOwner) } } }
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