/** *Submitted for verification at BscScan.com on 2021-05-03 */
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/proxy/Proxy.sol
pragma solidity ^0.8.0;
/**
-
@dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
-
instruction
delegatecall
. We refer to the second contract as the implementation behind the proxy, and it has to -
be specified by overriding the virtual {_implementation} function.
-
Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
-
different contract through the {_delegate} function.
-
The success and return data of the delegated call will be returned back to the caller of the proxy. / abstract contract Proxy { /*
-
@dev Delegates the current call to
implementation
. -
This function does not return to its internall call site, it will return directly to the external caller. */ function _delegate(address implementation) internal virtual { // solhint-disable-next-line no-inline-assembly assembly { // Copy msg.data. We take full control of memory in this inline assembly // block because it will not return to Solidity code. We overwrite the // Solidity scratch pad at memory position 0. calldatacopy(0, 0, calldatasize())
// Call the implementation. // out and outsize are 0 because we don't know the size yet. let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0) // Copy the returned data. returndatacopy(0, 0, returndatasize()) switch result // delegatecall returns 0 on error. case 0 { revert(0, returndatasize()) } default { return(0, returndatasize()) }
} }
/**
- @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
- and {_fallback} should delegate. */ function _implementation() internal view virtual returns (address);
/**
- @dev Delegates the current call to the address returned by
_implementation()
. - This function does not return to its internall call site, it will return directly to the external caller. */ function _fallback() internal virtual { _beforeFallback(); _delegate(_implementation()); }
/**
- @dev Fallback function that delegates calls to the address returned by
_implementation()
. Will run if no other - function in the contract matches the call data. */ fallback () external payable virtual { _fallback(); }
/**
- @dev Fallback function that delegates calls to the address returned by
_implementation()
. Will run if call data - is empty. */ receive () external payable virtual { _fallback(); }
/**
- @dev Hook that is called before falling back to the implementation. Can happen as part of a manual
_fallback
- call, or as part of the Solidity
fallback
orreceive
functions. - If overriden should call
super._beforeFallback()
. */ function _beforeFallback() internal virtual { } }
-
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/proxy/beacon/IBeacon.sol
pragma solidity ^0.8.0;
/**
- @dev This is the interface that {BeaconProxy} expects of its beacon.
/
interface IBeacon {
/*
- @dev Must return an address that can be used as a delegate call target.
- {BeaconProxy} will check that this address is a contract. */ function implementation() external view returns (address); }
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/utils/Address.sol
pragma solidity ^0.8.0;
/**
-
@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
: sendsamount
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
withdata
must not revert.
- calling
- 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 whentarget
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 totarget
. - Requirements:
-
- the calling contract must have an ETH balance of at least
value
.
- the calling contract must have an ETH balance of at least
-
- the called Solidity function must be
payable
.
- the called Solidity function must be
- 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 whentarget
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); }
/**
- @dev Same as {xref-Address-functionCall-address-bytes-}[
functionCall
], - but performing a delegate call.
- Available since v3.4. */ function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) { return functionDelegateCall(target, data, "Address: low-level delegate call failed"); }
/**
-
@dev Same as {xref-Address-functionCall-address-bytes-string-}[
functionCall
], -
but performing a delegate call.
-
Available since v3.4. */ function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) { require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.delegatecall(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); } }
} }
-
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/utils/StorageSlot.sol
pragma solidity ^0.8.0;
/**
-
@dev Library for reading and writing primitive types to specific storage slots.
-
Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
-
This library helps with reading and writing to such slots without the need for inline assembly.
-
The functions in this library return Slot structs that contain a
value
member that can be used to read or write. -
Example usage to set ERC1967 implementation slot:
-
-
contract ERC1967 {
-
bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
-
function _getImplementation() internal view returns (address) {
-
return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
-
}
-
function _setImplementation(address newImplementation) internal {
-
require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
-
StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
-
}
-
}
-
-
Available since v4.1 for
address
,bool
,bytes32
, anduint256
. */ library StorageSlot { struct AddressSlot { address value; }struct BooleanSlot { bool value; }
struct Bytes32Slot { bytes32 value; }
struct Uint256Slot { uint256 value; }
/**
- @dev Returns an
AddressSlot
with membervalue
located atslot
. */ function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) { assembly { r.slot := slot } }
/**
- @dev Returns an
BooleanSlot
with membervalue
located atslot
. */ function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) { assembly { r.slot := slot } }
/**
- @dev Returns an
Bytes32Slot
with membervalue
located atslot
. */ function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) { assembly { r.slot := slot } }
/**
- @dev Returns an
Uint256Slot
with membervalue
located atslot
. */ function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) { assembly { r.slot := slot } } }
- @dev Returns an
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/proxy/ERC1967/ERC1967Upgrade.sol
pragma solidity ^0.8.2;
/**
-
@dev This abstract contract provides getters and event emitting update functions for
-
Available since v4.1.
-
@custom:oz-upgrades-unsafe-allow delegatecall */ abstract contract ERC1967Upgrade { // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1 bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
/**
- @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 Emitted when the implementation is upgraded. */ event Upgraded(address indexed implementation);
/**
- @dev Returns the current implementation address. */ function _getImplementation() internal view returns (address) { return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value; }
/**
- @dev Stores a new address in the EIP1967 implementation slot. */ function _setImplementation(address newImplementation) private { require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract"); StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation; }
/**
- @dev Perform implementation upgrade
- Emits an {Upgraded} event. */ function _upgradeTo(address newImplementation) internal { _setImplementation(newImplementation); emit Upgraded(newImplementation); }
/**
- @dev Perform implementation upgrade with additional setup call.
- Emits an {Upgraded} event. */ function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal { _setImplementation(newImplementation); emit Upgraded(newImplementation); if (data.length > 0 || forceCall) { Address.functionDelegateCall(newImplementation, data); } }
/**
-
@dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
-
Emits an {Upgraded} event. */ function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal { address oldImplementation = _getImplementation();
// Initial upgrade and setup call _setImplementation(newImplementation); if (data.length > 0 || forceCall) { Address.functionDelegateCall(newImplementation, data); }
// Perform rollback test if not already in progress StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT); if (!rollbackTesting.value) { // Trigger rollback using upgradeTo from the new implementation rollbackTesting.value = true; Address.functionDelegateCall( newImplementation, abi.encodeWithSignature( "upgradeTo(address)", oldImplementation ) ); rollbackTesting.value = false; // Check rollback was effective require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades"); // Finally reset to the new implementation and log the upgrade _setImplementation(newImplementation); emit Upgraded(newImplementation); } }
/**
- @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
- not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
- Emits a {BeaconUpgraded} event. */ function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal { _setBeacon(newBeacon); emit BeaconUpgraded(newBeacon); if (data.length > 0 || forceCall) { Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data); } }
/**
- @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 the admin account has changed. */ event AdminChanged(address previousAdmin, address newAdmin);
/**
- @dev Returns the current admin. */ function _getAdmin() internal view returns (address) { return StorageSlot.getAddressSlot(_ADMIN_SLOT).value; }
/**
- @dev Stores a new address in the EIP1967 admin slot. */ function _setAdmin(address newAdmin) private { require(newAdmin != address(0), "ERC1967: new admin is the zero address"); StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin; }
/**
- @dev Changes the admin of the proxy.
- Emits an {AdminChanged} event. */ function _changeAdmin(address newAdmin) internal { emit AdminChanged(_getAdmin(), newAdmin); _setAdmin(newAdmin); }
/**
- @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 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
/**
- @dev Emitted when the beacon is upgraded. */ event BeaconUpgraded(address indexed beacon);
/**
- @dev Returns the current beacon. */ function _getBeacon() internal view returns (address) { return StorageSlot.getAddressSlot(_BEACON_SLOT).value; }
/**
- @dev Stores a new beacon in the EIP1967 beacon slot. */ function _setBeacon(address newBeacon) private { require( Address.isContract(newBeacon), "ERC1967: new beacon is not a contract" ); require( Address.isContract(IBeacon(newBeacon).implementation()), "ERC1967: beacon implementation is not a contract" ); StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon; } }
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/proxy/ERC1967/ERC1967Proxy.sol
pragma solidity ^0.8.0;
/**
-
@dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
-
implementation address that can be changed. This address is stored in storage in the location specified by
-
https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
-
implementation behind the proxy. / contract ERC1967Proxy is Proxy, ERC1967Upgrade { /*
- @dev Initializes the upgradeable proxy with an initial implementation specified by
_logic
. - If
_data
is nonempty, it's used as data in a delegate call to_logic
. This will typically be an encoded - function call, and allows initializating the storage of the proxy like a Solidity constructor. */ constructor(address _logic, bytes memory _data) payable { assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1)); _upgradeToAndCall(_logic, _data, false); }
/**
- @dev Returns the current implementation address. */ function _implementation() internal view virtual override returns (address impl) { return ERC1967Upgrade._getImplementation(); } }
- @dev Initializes the upgradeable proxy with an initial implementation specified by
// File: ../../../.brownie/packages/OpenZeppelin/openzeppelin-contracts@4.1.0/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
-
@dev This contract implements a proxy that is upgradeable by an admin.
-
To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
-
clashing], which can potentially be used in an attack, this contract uses the
-
https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
-
things that go hand in hand:
-
- If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
-
that call matches one of the admin functions exposed by the proxy itself.
-
- If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
-
implementation. If the admin tries to call a function on the implementation it will fail with an error that says
-
"admin cannot fallback to proxy target".
-
These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
-
the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
-
to sudden errors when trying to call a function from the proxy implementation.
-
Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
-
you should think of the
ProxyAdmin
instance as the real administrative interface of your proxy. / contract TransparentUpgradeableProxy is ERC1967Proxy { /*- @dev Initializes an upgradeable proxy managed by
_admin
, backed by the implementation at_logic
, and - optionally initialized with
_data
as explained in {ERC1967Proxy-constructor}. */ constructor(address logic, address admin, bytes memory _data) payable ERC1967Proxy(_logic, _data) { assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1)); changeAdmin(admin); }
/**
- @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin. */ modifier ifAdmin() { if (msg.sender == _getAdmin()) { _; } else { _fallback(); } }
/**
- @dev Returns the current admin.
- NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
- 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 ifAdmin returns (address admin_) { admin_ = _getAdmin(); }
/**
- @dev Returns the current implementation.
- NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
- 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 ifAdmin returns (address implementation_) { implementation_ = _implementation(); }
/**
- @dev Changes the admin of the proxy.
- Emits an {AdminChanged} event.
- NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}. */ function changeAdmin(address newAdmin) external virtual ifAdmin { _changeAdmin(newAdmin); }
/**
- @dev Upgrade the implementation of the proxy.
- NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}. */ function upgradeTo(address newImplementation) external ifAdmin { _upgradeToAndCall(newImplementation, bytes(""), false); }
/**
- @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
- by
data
, which should be an encoded function call. This is useful to initialize new storage variables in the - proxied contract.
- NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}. */ function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin { _upgradeToAndCall(newImplementation, data, true); }
/**
- @dev Returns the current admin. */ function _admin() internal view virtual returns (address) { return _getAdmin(); }
/**
- @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}. */ function _beforeFallback() internal virtual override { require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target"); super._beforeFallback(); } }
- @dev Initializes an upgradeable proxy managed by