Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.3;
import "@openzeppelin/contracts/utils/Address.sol";
import "./GraphProxyStorage.sol";
/**
* @title Graph Proxy
* @dev Graph Proxy contract used to delegate call implementation contracts and support upgrades.
* This contract should NOT define storage as it is managed by GraphProxyStorage.
* This contract implements a proxy that is upgradeable by an admin.
* https://docs.openzeppelin.com/upgrades-plugins/1.x/proxies#transparent-proxies-and-function-clashes
*/
contract GraphProxy is GraphProxyStorage {
/**
* @dev Modifier used internally that will delegate the call to the implementation unless
* the sender is the admin.
*/
modifier ifAdmin() {
if (msg.sender == _admin()) {
_;
} else {
_fallback();
}
}
/**
* @dev Modifier used internally that will delegate the call to the implementation unless
* the sender is the admin or pending implementation.
*/
modifier ifAdminOrPendingImpl() {
if (msg.sender == _admin() || msg.sender == _pendingImplementation()) {
_;
} else {
_fallback();
}
}
/**
* @dev Contract constructor.
* @param _impl Address of the initial implementation
* @param _admin Address of the proxy admin
*/
constructor(address _impl, address _admin) {
assert(ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
assert(
IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1)
);
assert(
PENDING_IMPLEMENTATION_SLOT ==
bytes32(uint256(keccak256("eip1967.proxy.pendingImplementation")) - 1)
);
_setAdmin(_admin);
_setPendingImplementation(_impl);
}
/**
* @dev Returns the current admin.
*
* NOTE: Only the admin and implementation can call this function.
*
* TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
* https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
* `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
*/
function admin() external ifAdminOrPendingImpl returns (address) {
return _admin();
}
/**
* @dev Returns the current implementation.
*
* NOTE: Only the admin can call this function.
*
* TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
* https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
* `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
*/
function implementation() external ifAdminOrPendingImpl returns (address) {
return _implementation();
}
/**
* @dev Returns the current pending implementation.
*
* NOTE: Only the admin can call this function.
*
* TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
* https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
* `0x9e5eddc59e0b171f57125ab86bee043d9128098c3a6b9adb4f2e86333c2f6f8c`
*/
function pendingImplementation() external ifAdminOrPendingImpl returns (address) {
return _pendingImplementation();
}
/**
* @dev Changes the admin of the proxy.
*
* NOTE: Only the admin can call this function.
*/
function setAdmin(address _newAdmin) external ifAdmin {
require(_newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
_setAdmin(_newAdmin);
}
/**
* @dev Upgrades to a new implementation contract.
* @param _newImplementation Address of implementation contract
*
* NOTE: Only the admin can call this function.
*/
function upgradeTo(address _newImplementation) external ifAdmin {
_setPendingImplementation(_newImplementation);
}
/**
* @dev Admin function for new implementation to accept its role as implementation.
*/
function acceptUpgrade() external ifAdminOrPendingImpl {
_acceptUpgrade();
}
/**
* @dev Admin function for new implementation to accept its role as implementation.
*/
function acceptUpgradeAndCall(bytes calldata data) external ifAdminOrPendingImpl {
_acceptUpgrade();
// solhint-disable-next-line avoid-low-level-calls
(bool success, ) = _implementation().delegatecall(data);
require(success);
}
/**
* @dev Admin function for new implementation to accept its role as implementation.
*/
function _acceptUpgrade() internal {
address _pendingImplementation = _pendingImplementation();
require(Address.isContract(_pendingImplementation), "Implementation must be a contract");
require(
_pendingImplementation != address(0) && msg.sender == _pendingImplementation,
"Caller must be the pending implementation"
);
_setImplementation(_pendingImplementation);
_setPendingImplementation(address(0));
}
/**
* @dev Delegates the current call to implementation.
* This function does not return to its internal call site, it will return directly to the
* external caller.
*/
function _fallback() internal {
require(msg.sender != _admin(), "Cannot fallback to proxy target");
assembly {
// (a) get free memory pointer
let ptr := mload(0x40)
// (b) get address of the implementation
let impl := and(sload(IMPLEMENTATION_SLOT), 0xffffffffffffffffffffffffffffffffffffffff)
// (1) copy incoming call data
calldatacopy(ptr, 0, calldatasize())
// (2) forward call to logic contract
let result := delegatecall(gas(), impl, ptr, calldatasize(), 0, 0)
let size := returndatasize()
// (3) retrieve return data
returndatacopy(ptr, 0, size)
// (4) forward return data back to caller
switch result
case 0 {
revert(ptr, size)
}
default {
return(ptr, size)
}
}
}
/**
* @dev Fallback function that delegates calls to implementation. Will run if no other
* function in the contract matches the call data.
*/
fallback() external payable {
_fallback();
}
/**
* @dev Fallback function that delegates calls to implementation. Will run if call data
* is empty.
*/
receive() external payable {
_fallback();
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.3;
/**
* @title Graph Proxy Storage
* @dev Contract functions related to getting and setting proxy storage.
* This contract does not actually define state variables managed by the compiler
* but uses fixed slot locations.
*/
contract GraphProxyStorage {
/**
* @dev Storage slot with the address of the current implementation.
* This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
* validated in the constructor.
*/
bytes32
internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
/**
* @dev Storage slot with the address of the pending implementation.
* This is the keccak-256 hash of "eip1967.proxy.pendingImplementation" subtracted by 1, and is
* validated in the constructor.
*/
bytes32
internal constant PENDING_IMPLEMENTATION_SLOT = 0x9e5eddc59e0b171f57125ab86bee043d9128098c3a6b9adb4f2e86333c2f6f8c;
/**
* @dev Storage slot with the admin of the contract.
* This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
* validated in the constructor.
*/
bytes32
internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
/**
* @dev Emitted when pendingImplementation is changed.
*/
event PendingImplementationUpdated(
address indexed oldPendingImplementation,
address indexed newPendingImplementation
);
/**
* @dev Emitted when pendingImplementation is accepted,
* which means contract implementation is updated.
*/
event ImplementationUpdated(
address indexed oldImplementation,
address indexed newImplementation
);
/**
* @dev Emitted when the admin account has changed.
*/
event AdminUpdated(address indexed oldAdmin, address indexed newAdmin);
/**
* @dev Modifier to check whether the `msg.sender` is the admin.
*/
modifier onlyAdmin() {
require(msg.sender == _admin(), "Caller must be admin");
_;
}
/**
* @return adm The admin slot.
*/
function _admin() internal view returns (address adm) {
bytes32 slot = ADMIN_SLOT;
assembly {
adm := sload(slot)
}
}
/**
* @dev Sets the address of the proxy admin.
* @param _newAdmin Address of the new proxy admin
*/
function _setAdmin(address _newAdmin) internal {
bytes32 slot = ADMIN_SLOT;
assembly {
sstore(slot, _newAdmin)
}
emit AdminUpdated(_admin(), _newAdmin);
}
/**
* @dev Returns the current implementation.
* @return impl Address of the current implementation
*/
function _implementation() internal view returns (address impl) {
bytes32 slot = IMPLEMENTATION_SLOT;
assembly {
impl := sload(slot)
}
}
/**
* @dev Returns the current pending implementation.
* @return impl Address of the current pending implementation
*/
function _pendingImplementation() internal view returns (address impl) {
bytes32 slot = PENDING_IMPLEMENTATION_SLOT;
assembly {
impl := sload(slot)
}
}
/**
* @dev Sets the implementation address of the proxy.
* @param _newImplementation Address of the new implementation
*/
function _setImplementation(address _newImplementation) internal {
address oldImplementation = _implementation();
bytes32 slot = IMPLEMENTATION_SLOT;
assembly {
sstore(slot, _newImplementation)
}
emit ImplementationUpdated(oldImplementation, _newImplementation);
}
/**
* @dev Sets the pending implementation address of the proxy.
* @param _newImplementation Address of the new pending implementation
*/
function _setPendingImplementation(address _newImplementation) internal {
address oldPendingImplementation = _pendingImplementation();
bytes32 slot = PENDING_IMPLEMENTATION_SLOT;
assembly {
sstore(slot, _newImplementation)
}
emit PendingImplementationUpdated(oldPendingImplementation, _newImplementation);
}
}
