Contract Source Code:
// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;
/**
* @dev Intended to update the TWAP for a token based on accepting an update call from that token.
* expectation is to have this happen in the _beforeTokenTransfer function of ERC20.
* Provides a method for a token to register its price sourve adaptor.
* Provides a function for a token to register its TWAP updater. Defaults to token itself.
* Provides a function a tokent to set its TWAP epoch.
* Implements automatic closeing and opening up a TWAP epoch when epoch ends.
* Provides a function to report the TWAP from the last epoch when passed a token address.
*/
interface ITWAPOracle {
function uniV2CompPairAddressForLastEpochUpdateBlockTimstamp( address ) external returns ( uint32 );
function priceTokenAddressForPricingTokenAddressForLastEpochUpdateBlockTimstamp( address tokenToPrice_, address tokenForPriceComparison_, uint epochPeriod_ ) external returns ( uint32 );
function pricedTokenForPricingTokenForEpochPeriodForPrice( address, address, uint ) external returns ( uint );
function pricedTokenForPricingTokenForEpochPeriodForLastEpochPrice( address, address, uint ) external returns ( uint );
function updateTWAP( address uniV2CompatPairAddressToUpdate_, uint eopchPeriodToUpdate_ ) external returns ( bool );
}
library EnumerableSet {
// To implement this library for multiple types with as little code
// repetition as possible, we write it in terms of a generic Set type with
// bytes32 values.
// The Set implementation uses private functions, and user-facing
// implementations (such as AddressSet) are just wrappers around the
// underlying Set.
// This means that we can only create new EnumerableSets for types that fit
// in bytes32.
struct Set {
// Storage of set values
bytes32[] _values;
// Position of the value in the `values` array, plus 1 because index 0
// means a value is not in the set.
mapping (bytes32 => uint256) _indexes;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function _add(Set storage set, bytes32 value) private returns (bool) {
if (!_contains(set, value)) {
set._values.push(value);
// The value is stored at length-1, but we add 1 to all indexes
// and use 0 as a sentinel value
set._indexes[value] = set._values.length;
return true;
} else {
return false;
}
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function _remove(Set storage set, bytes32 value) private returns (bool) {
// We read and store the value's index to prevent multiple reads from the same storage slot
uint256 valueIndex = set._indexes[value];
if (valueIndex != 0) { // Equivalent to contains(set, value)
// To delete an element from the _values array in O(1), we swap the element to delete with the last one in
// the array, and then remove the last element (sometimes called as 'swap and pop').
// This modifies the order of the array, as noted in {at}.
uint256 toDeleteIndex = valueIndex - 1;
uint256 lastIndex = set._values.length - 1;
// When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
// so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
bytes32 lastvalue = set._values[lastIndex];
// Move the last value to the index where the value to delete is
set._values[toDeleteIndex] = lastvalue;
// Update the index for the moved value
set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
// Delete the slot where the moved value was stored
set._values.pop();
// Delete the index for the deleted slot
delete set._indexes[value];
return true;
} else {
return false;
}
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function _contains(Set storage set, bytes32 value) private view returns (bool) {
return set._indexes[value] != 0;
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function _length(Set storage set) private view returns (uint256) {
return set._values.length;
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function _at(Set storage set, uint256 index) private view returns (bytes32) {
require(set._values.length > index, "EnumerableSet: index out of bounds");
return set._values[index];
}
function _getValues( Set storage set_ ) private view returns ( bytes32[] storage ) {
return set_._values;
}
// TODO needs insert function that maintains order.
// TODO needs NatSpec documentation comment.
/**
* Inserts new value by moving existing value at provided index to end of array and setting provided value at provided index
*/
function _insert(Set storage set_, uint256 index_, bytes32 valueToInsert_ ) private returns ( bool ) {
require( set_._values.length > index_ );
require( !_contains( set_, valueToInsert_ ), "Remove value you wish to insert if you wish to reorder array." );
bytes32 existingValue_ = _at( set_, index_ );
set_._values[index_] = valueToInsert_;
return _add( set_, existingValue_);
}
struct Bytes4Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes4Set storage set, bytes4 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes4Set storage set, bytes4 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes4Set storage set, bytes4 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(Bytes4Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes4Set storage set, uint256 index) internal view returns ( bytes4 ) {
return bytes4( _at( set._inner, index ) );
}
function getValues( Bytes4Set storage set_ ) internal view returns ( bytes4[] memory ) {
bytes4[] memory bytes4Array_;
for( uint256 iteration_ = 0; _length( set_._inner ) > iteration_; iteration_++ ) {
bytes4Array_[iteration_] = bytes4( _at( set_._inner, iteration_ ) );
}
return bytes4Array_;
}
function insert( Bytes4Set storage set_, uint256 index_, bytes4 valueToInsert_ ) internal returns ( bool ) {
return _insert( set_._inner, index_, valueToInsert_ );
}
struct Bytes32Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(Bytes32Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes32Set storage set, uint256 index) internal view returns ( bytes32 ) {
return _at(set._inner, index);
}
function getValues( Bytes32Set storage set_ ) internal view returns ( bytes4[] memory ) {
bytes4[] memory bytes4Array_;
for( uint256 iteration_ = 0; _length( set_._inner ) >= iteration_; iteration_++ ){
bytes4Array_[iteration_] = bytes4( at( set_, iteration_ ) );
}
return bytes4Array_;
}
function insert( Bytes32Set storage set_, uint256 index_, bytes32 valueToInsert_ ) internal returns ( bool ) {
return _insert( set_._inner, index_, valueToInsert_ );
}
// AddressSet
struct AddressSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(AddressSet storage set, address value) internal returns (bool) {
return _add(set._inner, bytes32(uint256(value)));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(AddressSet storage set, address value) internal returns (bool) {
return _remove(set._inner, bytes32(uint256(value)));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(AddressSet storage set, address value) internal view returns (bool) {
return _contains(set._inner, bytes32(uint256(value)));
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(AddressSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(AddressSet storage set, uint256 index) internal view returns (address) {
return address(uint256(_at(set._inner, index)));
}
/**
* TODO Might require explicit conversion of bytes32[] to address[].
* Might require iteration.
*/
function getValues( AddressSet storage set_ ) internal view returns ( address[] memory ) {
address[] memory addressArray;
for( uint256 iteration_ = 0; _length(set_._inner) >= iteration_; iteration_++ ){
addressArray[iteration_] = at( set_, iteration_ );
}
return addressArray;
}
function insert(AddressSet storage set_, uint256 index_, address valueToInsert_ ) internal returns ( bool ) {
return _insert( set_._inner, index_, bytes32(uint256(valueToInsert_)) );
}
// UintSet
struct UintSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UintSet storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UintSet storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UintSet storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(UintSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UintSet storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
struct UInt256Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UInt256Set storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UInt256Set storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UInt256Set storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(UInt256Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UInt256Set storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
}
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
function sqrrt(uint256 a) internal pure returns (uint c) {
if (a > 3) {
c = a;
uint b = add( div( a, 2), 1 );
while (b < c) {
c = b;
b = div( add( div( a, b ), b), 2 );
}
} else if (a != 0) {
c = 1;
}
}
/*
* Expects percentage to be trailed by 00,
*/
function percentageAmount( uint256 total_, uint8 percentage_ ) internal pure returns ( uint256 percentAmount_ ) {
return div( mul( total_, percentage_ ), 1000 );
}
/*
* Expects percentage to be trailed by 00,
*/
function substractPercentage( uint256 total_, uint8 percentageToSub_ ) internal pure returns ( uint256 result_ ) {
return sub( total_, div( mul( total_, percentageToSub_ ), 1000 ) );
}
function percentageOfTotal( uint256 part_, uint256 total_ ) internal pure returns ( uint256 percent_ ) {
return div( mul(part_, 100) , total_ );
}
/**
* Taken from Hypersonic https://github.com/M2629/HyperSonic/blob/main/Math.sol
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow, so we distribute
return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
}
function quadraticPricing( uint256 payment_, uint256 multiplier_ ) internal pure returns (uint256) {
return sqrrt( mul( multiplier_, payment_ ) );
}
function bondingCurve( uint256 supply_, uint256 multiplier_ ) internal pure returns (uint256) {
return mul( multiplier_, supply_ );
}
}
abstract contract ERC20
is
IERC20
{
using SafeMath for uint256;
// TODO comment actual hash value.
bytes32 constant private ERC20TOKEN_ERC1820_INTERFACE_ID = keccak256( "ERC20Token" );
// Present in ERC777
mapping (address => uint256) internal _balances;
// Present in ERC777
mapping (address => mapping (address => uint256)) internal _allowances;
// Present in ERC777
uint256 internal _totalSupply;
// Present in ERC777
string internal _name;
// Present in ERC777
string internal _symbol;
// Present in ERC777
uint8 internal _decimals;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor (string memory name_, string memory symbol_, uint8 decimals_) {
_name = name_;
_symbol = symbol_;
_decimals = decimals_;
}
/**
* @dev Returns the name of the token.
*/
// Present in ERC777
function name() public view returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
// Present in ERC777
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
// Present in ERC777
function decimals() public view returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
// Present in ERC777
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
// Present in ERC777
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
// Overrideen in ERC777
// Confirm that this behavior changes
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(msg.sender, recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
// Present in ERC777
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
// Present in ERC777
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
// Present in ERC777
function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(address sender, address recipient, uint256 amount) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `to` cannot be the zero address.
*/
// Present in ERC777
function _mint(address account_, uint256 amount_) internal virtual {
require(account_ != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address( this ), account_, amount_);
_totalSupply = _totalSupply.add(amount_);
_balances[account_] = _balances[account_].add(amount_);
emit Transfer(address( this ), account_, amount_);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
// Present in ERC777
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
// Present in ERC777
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
// Considering deprication to reduce size of bytecode as changing _decimals to internal acheived the same functionality.
// function _setupDecimals(uint8 decimals_) internal {
// _decimals = decimals_;
// }
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
// Present in ERC777
function _beforeTokenTransfer( address from_, address to_, uint256 amount_ ) internal virtual { }
}
library Counters {
using SafeMath for uint256;
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
// The {SafeMath} overflow check can be skipped here, see the comment at the top
counter._value += 1;
}
function decrement(Counter storage counter) internal {
counter._value = counter._value.sub(1);
}
}
interface IERC2612Permit {
/**
* @dev Sets `amount` as the allowance of `spender` over `owner`'s tokens,
* given `owner`'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 amount,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current ERC2612 nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
}
abstract contract ERC20Permit is ERC20, IERC2612Permit {
using Counters for Counters.Counter;
mapping(address => Counters.Counter) private _nonces;
// keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
bytes32 public DOMAIN_SEPARATOR;
constructor() {
uint256 chainID;
assembly {
chainID := chainid()
}
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
keccak256(bytes(name())),
keccak256(bytes("1")), // Version
chainID,
address(this)
)
);
}
/**
* @dev See {IERC2612Permit-permit}.
*
*/
function permit(
address owner,
address spender,
uint256 amount,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override {
require(block.timestamp <= deadline, "Permit: expired deadline");
bytes32 hashStruct =
keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, amount, _nonces[owner].current(), deadline));
bytes32 _hash = keccak256(abi.encodePacked(uint16(0x1901), DOMAIN_SEPARATOR, hashStruct));
address signer = ecrecover(_hash, v, r, s);
require(signer != address(0) && signer == owner, "ZeroSwapPermit: Invalid signature");
_nonces[owner].increment();
_approve(owner, spender, amount);
}
/**
* @dev See {IERC2612Permit-nonces}.
*/
function nonces(address owner) public view override returns (uint256) {
return _nonces[owner].current();
}
}
interface IOwnable {
function owner() external view returns (address);
function renounceOwnership() external;
function transferOwnership( address newOwner_ ) external;
}
contract Ownable is IOwnable {
address internal _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () {
_owner = msg.sender;
emit OwnershipTransferred( address(0), _owner );
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view override returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require( _owner == msg.sender, "Ownable: caller is not the owner" );
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual override onlyOwner() {
emit OwnershipTransferred( _owner, address(0) );
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership( address newOwner_ ) public virtual override onlyOwner() {
require( newOwner_ != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred( _owner, newOwner_ );
_owner = newOwner_;
}
}
contract VaultOwned is Ownable {
address internal _vault;
function setVault( address vault_ ) external onlyOwner() returns ( bool ) {
_vault = vault_;
return true;
}
/**
* @dev Returns the address of the current vault.
*/
function vault() public view returns (address) {
return _vault;
}
/**
* @dev Throws if called by any account other than the vault.
*/
modifier onlyVault() {
require( _vault == msg.sender, "VaultOwned: caller is not the Vault" );
_;
}
}
contract TWAPOracleUpdater is ERC20Permit, VaultOwned {
using EnumerableSet for EnumerableSet.AddressSet;
event TWAPOracleChanged( address indexed previousTWAPOracle, address indexed newTWAPOracle );
event TWAPEpochChanged( uint previousTWAPEpochPeriod, uint newTWAPEpochPeriod );
event TWAPSourceAdded( address indexed newTWAPSource );
event TWAPSourceRemoved( address indexed removedTWAPSource );
EnumerableSet.AddressSet private _dexPoolsTWAPSources;
ITWAPOracle public twapOracle;
uint public twapEpochPeriod;
constructor(
string memory name_,
string memory symbol_,
uint8 decimals_
) ERC20(name_, symbol_, decimals_) {
}
function changeTWAPOracle( address newTWAPOracle_ ) external onlyOwner() {
emit TWAPOracleChanged( address(twapOracle), newTWAPOracle_);
twapOracle = ITWAPOracle( newTWAPOracle_ );
}
function changeTWAPEpochPeriod( uint newTWAPEpochPeriod_ ) external onlyOwner() {
require( newTWAPEpochPeriod_ > 0, "TWAPOracleUpdater: TWAP Epoch period must be greater than 0." );
emit TWAPEpochChanged( twapEpochPeriod, newTWAPEpochPeriod_ );
twapEpochPeriod = newTWAPEpochPeriod_;
}
function addTWAPSource( address newTWAPSourceDexPool_ ) external onlyOwner() {
require( _dexPoolsTWAPSources.add( newTWAPSourceDexPool_ ), "OlympusERC20TOken: TWAP Source already stored." );
emit TWAPSourceAdded( newTWAPSourceDexPool_ );
}
function removeTWAPSource( address twapSourceToRemove_ ) external onlyOwner() {
require( _dexPoolsTWAPSources.remove( twapSourceToRemove_ ), "OlympusERC20TOken: TWAP source not present." );
emit TWAPSourceRemoved( twapSourceToRemove_ );
}
function _uodateTWAPOracle( address dexPoolToUpdateFrom_, uint twapEpochPeriodToUpdate_ ) internal {
if ( _dexPoolsTWAPSources.contains( dexPoolToUpdateFrom_ )) {
twapOracle.updateTWAP( dexPoolToUpdateFrom_, twapEpochPeriodToUpdate_ );
}
}
function _beforeTokenTransfer( address from_, address to_, uint256 amount_ ) internal override virtual {
if( _dexPoolsTWAPSources.contains( from_ ) ) {
_uodateTWAPOracle( from_, twapEpochPeriod );
} else {
if ( _dexPoolsTWAPSources.contains( to_ ) ) {
_uodateTWAPOracle( to_, twapEpochPeriod );
}
}
}
}
contract Divine is TWAPOracleUpdater {
constructor(
string memory name_,
string memory symbol_,
uint8 decimals_
) TWAPOracleUpdater(name_, symbol_, decimals_) {
}
}
contract BRRRERC20 is Divine {
using SafeMath for uint256;
constructor() Divine("BRRR", "BRRR", 9) {
}
function mint(address account_, uint256 amount_) external onlyVault() {
_mint(account_, amount_);
}
/**
* @dev Destroys `amount` tokens from the caller.
*
* See {ERC20-_burn}.
*/
function burn(uint256 amount) public virtual {
_burn(msg.sender, amount);
}
// function _beforeTokenTransfer( address from_, address to_, uint256 amount_ ) internal override virtual {
// if( _dexPoolsTWAPSources.contains( from_ ) ) {
// _uodateTWAPOracle( from_, twapEpochPeriod );
// } else {
// if ( _dexPoolsTWAPSources.contains( to_ ) ) {
// _uodateTWAPOracle( to_, twapEpochPeriod );
// }
// }
// }
/*
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for ``accounts``'s tokens of at least
* `amount`.
*/
function burnFrom(address account_, uint256 amount_) public virtual {
_burnFrom(account_, amount_);
}
function _burnFrom(address account_, uint256 amount_) public virtual {
uint256 decreasedAllowance_ =
allowance(account_, msg.sender).sub(
amount_,
"ERC20: burn amount exceeds allowance"
);
_approve(account_, msg.sender, decreasedAllowance_);
_burn(account_, amount_);
}
}