mirror of openzeppelin-contracts
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
openzeppelin-contracts/contracts/proxy/BeaconProxy.sol

86 lines
2.9 KiB

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "./Proxy.sol";
import "../utils/Address.sol";
import "./IBeacon.sol";
/**
* @dev This contract implements a proxy that gets the implementation address for each call from a {UpgradeableBeacon}.
*
* The beacon address is stored in storage slot `uint256(keccak256('eip1967.proxy.beacon')) - 1`, so that it doesn't
* conflict with the storage layout of the implementation behind the proxy.
*/
contract BeaconProxy is Proxy {
/**
* @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
* This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
*/
bytes32 private constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
/**
* @dev Initializes the proxy with `beacon`.
*
* If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon. This
* will typically be an encoded function call, and allows initializating the storage of the proxy like a Solidity
* constructor.
*
* Requirements:
*
* - `beacon` must be a contract with the interface {IBeacon}.
*/
constructor(address beacon, bytes memory data) public payable {
assert(_BEACON_SLOT == bytes32(uint256(keccak256("eip1967.proxy.beacon")) - 1));
_setBeacon(beacon, data);
}
/**
* @dev Returns the current beacon address.
*/
function _beacon() internal view returns (address beacon) {
bytes32 slot = _BEACON_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
beacon := sload(slot)
}
}
/**
* @dev Returns the current implementation address of the associated beacon.
*/
function _implementation() internal view override returns (address) {
return IBeacon(_beacon()).implementation();
}
/**
* @dev Changes the proxy to use a new beacon.
*
* If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon.
*
* Requirements:
*
* - `beacon` must be a contract.
* - The implementation returned by `beacon` must be a contract.
*/
function _setBeacon(address beacon, bytes memory data) internal {
require(
Address.isContract(beacon),
"BeaconProxy: beacon is not a contract"
);
require(
Address.isContract(IBeacon(beacon).implementation()),
"BeaconProxy: beacon implementation is not a contract"
);
bytes32 slot = _BEACON_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
sstore(slot, beacon)
}
if (data.length > 0) {
Address.functionDelegateCall(_implementation(), data, "BeaconProxy: function call failed");
}
}
}