Contract Source Code:
File 1 of 1 : ReadProxy
/*
____ __ __ __ _
/ __/__ __ ___ / /_ / / ___ / /_ (_)__ __
_\ \ / // // _ \/ __// _ \/ -_)/ __// / \ \ /
/___/ \_, //_//_/\__//_//_/\__/ \__//_/ /_\_\
/___/
* Synthetix: ReadProxy.sol
*
* Latest source (may be newer): https://github.com/Synthetixio/synthetix/blob/master/contracts/ReadProxy.sol
* Docs: https://docs.synthetix.io/contracts/ReadProxy
*
* Contract Dependencies:
* - Owned
* Libraries: (none)
*
* MIT License
* ===========
*
* Copyright (c) 2020 Synthetix
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
*/
/* ===============================================
* Flattened with Solidifier by Coinage
*
* https://solidifier.coina.ge
* ===============================================
*/
pragma solidity ^0.5.16;
// https://docs.synthetix.io/contracts/Owned
contract Owned {
address public owner;
address public nominatedOwner;
constructor(address _owner) public {
require(_owner != address(0), "Owner address cannot be 0");
owner = _owner;
emit OwnerChanged(address(0), _owner);
}
function nominateNewOwner(address _owner) external onlyOwner {
nominatedOwner = _owner;
emit OwnerNominated(_owner);
}
function acceptOwnership() external {
require(msg.sender == nominatedOwner, "You must be nominated before you can accept ownership");
emit OwnerChanged(owner, nominatedOwner);
owner = nominatedOwner;
nominatedOwner = address(0);
}
modifier onlyOwner {
require(msg.sender == owner, "Only the contract owner may perform this action");
_;
}
event OwnerNominated(address newOwner);
event OwnerChanged(address oldOwner, address newOwner);
}
// solhint-disable payable-fallback
// https://docs.synthetix.io/contracts/ReadProxy
contract ReadProxy is Owned {
address public target;
constructor(address _owner) public Owned(_owner) {}
function setTarget(address _target) external onlyOwner {
target = _target;
emit TargetUpdated(target);
}
function() external {
// The basics of a proxy read call
// Note that msg.sender in the underlying will always be the address of this contract.
assembly {
calldatacopy(0, 0, calldatasize)
// Use of staticcall - this will revert if the underlying function mutates state
let result := staticcall(gas, sload(target_slot), 0, calldatasize, 0, 0)
returndatacopy(0, 0, returndatasize)
if iszero(result) {
revert(0, returndatasize)
}
return(0, returndatasize)
}
}
event TargetUpdated(address newTarget);
}