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May 3, 2018 16:00
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pragma solidity ^0.4.18; | |
/** | |
* @title Ownable | |
* @dev The Ownable contract has an owner address, and provides basic authorization control | |
* functions, this simplifies the implementation of "user permissions". | |
* @author https://github.com/OpenZeppelin/zeppelin-solidity | |
*/ | |
contract Ownable { | |
address public owner; | |
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); | |
/** | |
* @dev The Ownable constructor sets the original `owner` of the contract to the sender | |
* account. | |
*/ | |
function Ownable() public { | |
owner = msg.sender; | |
} | |
/** | |
* @dev Throws if called by any account other than the owner. | |
*/ | |
modifier onlyOwner() { | |
require(msg.sender == owner); | |
_; | |
} | |
/** | |
* @dev Allows the current owner to transfer control of the contract to a newOwner. | |
* @param newOwner The address to transfer ownership to. | |
*/ | |
function transferOwnership(address newOwner) public onlyOwner { | |
require(newOwner != address(0)); | |
OwnershipTransferred(owner, newOwner); | |
owner = newOwner; | |
} | |
} | |
contract Proxied is Ownable { | |
address public target; | |
mapping (address => bool) public initialized; | |
event EventUpgrade(address indexed newTarget, address indexed oldTarget, address indexed admin); | |
event EventInitialized(address indexed target); | |
function upgradeTo(address _target) public; | |
} | |
contract Proxy is Proxied { | |
constructor(address _target) public { | |
upgradeTo(_target); | |
} | |
// onlyOwner moifier has been applied to function | |
function upgradeTo(address _target) public onlyOwner { | |
assert(target != _target); | |
address oldTarget = target; | |
target = _target; | |
emit EventUpgrade(_target, oldTarget, msg.sender); | |
} | |
function () payable public { | |
bytes memory data = msg.data; | |
address impl = target; | |
assembly { | |
let result := delegatecall(gas, impl, add(data, 0x20), mload(data), 0, 0) | |
let size := returndatasize | |
let ptr := mload(0x40) | |
returndatacopy(ptr, 0, size) | |
switch result | |
case 0 { revert(ptr, size) } | |
default { return(ptr, size) } | |
} | |
} | |
} | |
contract Upgradeable is Proxied { | |
/** | |
* This function, as it is here, will never be executed. The function that will execute will be | |
* Proxy.upgradeTo(address) | |
*/ | |
function upgradeTo(address) public { | |
assert(false); | |
} | |
/** | |
* This abstract function needs to be implemented in child contracts if the child contrat requires | |
* variable initialization on creation. This is because, the contructor of the Proxy contract will not | |
* initialize any of the upgradeable child contract's variables when the target is set | |
*/ | |
function initialize() public; // { | |
// if(initializeUpgradeable(target)) { | |
// // initialize contract variables here | |
// } | |
// } | |
function initializeUpgradeable(address target) internal returns (bool) { | |
if(!initialized[target]) { | |
initialized[target] = true; | |
emit EventInitialized(target); | |
return true; | |
} | |
else return false; | |
} | |
} |
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