Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` 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:
*
* - `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 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;
/**
* @dev Returns the current 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);
/**
* @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b > a) return (false, 0);
return (true, a - b);
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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 (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a / b);
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a % b);
}
/**
* @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) {
require(b <= a, "SafeMath: subtraction overflow");
return a - b;
}
/**
* @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) {
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, reverting 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) {
require(b > 0, "SafeMath: division by zero");
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting 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) {
require(b > 0, "SafeMath: modulo by zero");
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* 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);
return a - b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* 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);
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* 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;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// 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);
}
/**
* @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);
}
}
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.7.6;
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "../interfaces/IIchiV2.sol";
contract IchiV2 is IIchiV2 {
using SafeMath for uint256;
using SafeERC20 for IERC20;
// EIP-20 token name for this token
string public constant override name = "ICHI";
// EIP-20 token symbol for this token
string public constant override symbol = "ICHI";
// EIP-20 token decimals for this token
uint8 public constant override decimals = 18;
// ICHI V1 address
address public immutable override ichiV1;
// constant that represents 100%
uint256 constant PERCENT = 100;
// constant that represents difference in decimals between ICHI V1 and ICHI V2 tokens
uint256 constant DECIMALS_DIFF = 1e9;
// constant that represents address(0)
address constant NULL_ADDRESS = address(0);
// Total number of tokens in circulation
// Initially capped at 5 million ICHI, another 5 million can be minted via swaps with ICHI V1
// On top of it 2% extra (inflationary) tokens can be minted with 1 year intervals
uint256 public override totalSupply = 5_000_000e18;
// Address which may mint inflationary tokens
address public override minter;
// The timestamp after which inflationary minting may occur
uint256 public override mintingAllowedAfter;
// Minimum time between inflationary mints
uint32 public constant override minimumTimeBetweenMints = 1 days * 365;
// Cap on the percentage of totalSupply that can be minted at each inflationary mint
uint8 public constant override mintCap = 2;
// ICHI V2 to ICHI V1 conversion fee (default is 0%)
uint256 public override conversionFee = 0;
// Allowance amounts on behalf of others
mapping (address => mapping (address => uint96)) internal allowances;
// Official record of token balances for each account
mapping (address => uint96) internal balances;
// A record of each accounts delegate
mapping (address => address) public override delegates;
// A checkpoint for marking number of votes from a given block
struct Checkpoint {
uint32 fromBlock;
uint96 votes;
}
// A record of votes checkpoints for each account, by index
mapping (address => mapping (uint32 => Checkpoint)) public override checkpoints;
// The number of checkpoints for each account
mapping (address => uint32) public override numCheckpoints;
// The EIP-712 typehash for the contract's domain
bytes32 public constant override DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
// The EIP-712 typehash for the delegation struct used by the contract
bytes32 public constant override DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");
// The EIP-712 typehash for the permit struct used by the contract
bytes32 public constant override PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
// A record of states for signing / validating signatures
mapping (address => uint256) public override nonces;
/**
* @notice Construct a new ICHI token
* @param account The initial account to grant 5 million tokens
* @param minter_ The account with minting ability
* @param ichi_v1_ ICHI V1 address
* @param mintingAllowedAfter_ The timestamp after which inflationary minting may occur
*/
constructor(address account, address minter_, address ichi_v1_, uint256 mintingAllowedAfter_) {
require(mintingAllowedAfter_ >= block.timestamp, "IchiV2.constructor: minting can only begin after deployment");
require(account != NULL_ADDRESS && minter_ != NULL_ADDRESS && ichi_v1_ != NULL_ADDRESS, "IchiV2.constructor: cannot init with zero addresses");
balances[account] = uint96(totalSupply);
ichiV1 = ichi_v1_;
minter = minter_;
mintingAllowedAfter = mintingAllowedAfter_;
emit Transfer(NULL_ADDRESS, account, totalSupply);
emit MinterChanged(NULL_ADDRESS, minter);
}
/**
* @notice Change the minter address
* @param minter_ The address of the new minter
*/
function setMinter(address minter_) external override {
require(msg.sender == minter, "IchiV2.setMinter: only the minter can change the minter address");
require(minter_ != NULL_ADDRESS, "IchiV2.setMinter: cannot use zero address");
emit MinterChanged(minter, minter_);
minter = minter_;
}
/**
* @notice Mint new tokens
* @param dst The address of the destination account
* @param amount The number of tokens to be minted
*/
function mint(address dst, uint256 amount) external override {
require(msg.sender == minter, "IchiV2.mint: only the minter can mint");
require(block.timestamp >= mintingAllowedAfter, "IchiV2.mint: minting not allowed yet");
require(dst != NULL_ADDRESS, "IchiV2.mint: cannot transfer to the zero address");
// record the mint
mintingAllowedAfter = block.timestamp.add(minimumTimeBetweenMints);
// mint the amount
uint96 amount96 = safe96(amount, "IchiV2.mint: amount exceeds 96 bits");
require(amount <= totalSupply.mul(mintCap).div(PERCENT), "IchiV2.mint: exceeded mint cap");
totalSupply = uint256(safe96(totalSupply.add(amount), "IchiV2.mint: totalSupply exceeds 96 bits"));
// transfer the amount to the recipient
balances[dst] = add96(balances[dst], amount96, "IchiV2.mint: destination balance overflows");
emit Transfer(NULL_ADDRESS, dst, amount);
// move delegates
_moveDelegates(NULL_ADDRESS, delegates[dst], amount96);
}
/**
* @notice Change the ICHI V2 to ICHI V1 conversion fee
* @param fee_ New conversion fee, 0-100%
*/
function setConversionFee(uint256 fee_) external override {
require(fee_ <= 100, "IchiV2.setConversionFee: fee must be <= 100");
require(msg.sender == minter, "IchiV2.setConversionFee: only the minter can change the converson fee");
conversionFee = fee_;
emit ConversionFeeChanged(minter, fee_);
}
/**
* @notice Convert ICHI V1 tokens to ICHI V2 tokens
* @param v1Amount The number of ICHI V1 tokens to be converted (using 9 decimals representation)
*/
function convertToV2(uint256 v1Amount) external override {
require(v1Amount > 0, "IchiV2.convertToV2: amount must be > 0");
// convert 9 decimals ICHI V1 to 18 decimals ICHI V2
uint256 v2Amount = v1Amount.mul(DECIMALS_DIFF);
uint96 v2Amount96 = safe96(v2Amount, "IchiV2.convertToV2: amount exceeds 96 bits");
// transfer ICHI V1 tokens in
IERC20(ichiV1).safeTransferFrom(msg.sender, address(this), v1Amount);
// increase ICHI V2 totalSupply
totalSupply = totalSupply.add(v2Amount);
// transfer the amount of ICHI V2 to the recipient
balances[msg.sender] = add96(balances[msg.sender], v2Amount96, "IchiV2.convertToV2: transfer amount overflows");
emit ConvertedToV2(msg.sender, v1Amount, v2Amount);
emit Transfer(NULL_ADDRESS, msg.sender, v2Amount);
// move delegates
_moveDelegates(NULL_ADDRESS, delegates[msg.sender], v2Amount96);
}
/**
* @notice Convert ICHI V2 tokens back to ICHI V1 tokens
* @param v2Amount The number of ICHI V2 tokens to be converted (using 18 decimals representation)
*/
function convertToV1(uint256 v2Amount) external override {
require(v2Amount > 0, "IchiV2.convertToV1: amount must be > 0");
uint96 v2Amount96 = safe96(v2Amount, "IchiV2.convertToV1: amount exceeds 96 bits");
require(v2Amount96 <= balances[msg.sender], "IchiV2.convertToV1: insufficient V2 balance");
// convert 18 decimals ICHI V2 to 9 decimals ICHI V2 and take off the conversion fee
uint256 v1Amount = v2Amount.mul(PERCENT.sub(conversionFee)).div(DECIMALS_DIFF).div(PERCENT);
require(v1Amount > 0, "IchiV2.convertToV1: amount is too small");
// decrease ICHI V2 totalSupply
totalSupply = totalSupply.sub(v2Amount);
// burn the traded amount of ICHI V2
balances[msg.sender] = sub96(balances[msg.sender], v2Amount96, "IchiV2.convertToV1: transfer amount overflows");
// transfer ICHI V1 tokens to the user
IERC20(ichiV1).safeTransfer(msg.sender, v1Amount);
emit ConvertedToV1(msg.sender, v2Amount96, v1Amount);
emit Transfer(msg.sender, NULL_ADDRESS, v2Amount96);
// move delegates
_moveDelegates(delegates[msg.sender], NULL_ADDRESS, v2Amount96);
}
/**
* @notice Get the number of tokens `spender` is approved to spend on behalf of `account`
* @param _owner The address of the account holding the funds
* @param _spender The address of the account spending the funds
* @return The number of tokens approved
*/
function allowance(address _owner, address _spender) external view override returns (uint256) {
return uint256(allowances[_owner][_spender]);
}
/**
* @notice Approve `spender` to transfer up to `amount` from `src`
* @dev This will overwrite the approval amount for `spender`
* and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
* @param _spender The address of the account which may transfer tokens
* @param _value The number of tokens that are approved (2^256-1 means infinite)
* @return Whether or not the approval succeeded
*/
function approve(address _spender, uint256 _value) external override returns (bool) {
uint96 amount;
if (_value == uint256(-1)) {
amount = uint96(-1);
} else {
amount = safe96(_value, "IchiV2.approve: amount exceeds 96 bits");
}
allowances[msg.sender][_spender] = amount;
emit Approval(msg.sender, _spender, uint256(amount));
return true;
}
/**
* @notice Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
* @return domain separator
*/
function DOMAIN_SEPARATOR() public view override returns (bytes32) {
return keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainId(), address(this)));
}
/**
* @notice Triggers an approval from owner to spends
* @param owner The address to approve from
* @param spender The address to be approved
* @param rawAmount The number of tokens that are approved (2^256-1 means infinite)
* @param deadline The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function permit(address owner, address spender, uint256 rawAmount, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external override {
uint96 amount;
if (rawAmount == uint256(-1)) {
amount = uint96(-1);
} else {
amount = safe96(rawAmount, "IchiV2.permit: amount exceeds 96 bits");
}
bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, rawAmount, nonces[owner]++, deadline));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR(), structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != NULL_ADDRESS, "IchiV2.permit: invalid signature");
require(signatory == owner, "IchiV2.permit: unauthorized");
require(block.timestamp <= deadline, "IchiV2.permit: signature expired");
allowances[owner][spender] = amount;
emit Approval(owner, spender, uint256(amount));
}
/**
* @notice Get the number of tokens held by the `account`
* @param _owner The address of the account to get the balance of
* @return The number of tokens held
*/
function balanceOf(address _owner) external view override returns (uint256) {
return uint256(balances[_owner]);
}
/**
* @notice Transfer `amount` tokens from `msg.sender` to `dst`
* @param _to The address of the destination account
* @param _value The number of tokens to transfer
* @return Whether or not the transfer succeeded
*/
function transfer(address _to, uint256 _value) external override returns (bool) {
uint96 amount = safe96(_value, "IchiV2.transfer: amount exceeds 96 bits");
_transferTokens(msg.sender, _to, amount);
return true;
}
/**
* @notice Transfer `amount` tokens from `src` to `dst`
* @param _from The address of the source account
* @param _to The address of the destination account
* @param _value The number of tokens to transfer
* @return Whether or not the transfer succeeded
*/
function transferFrom(address _from, address _to, uint256 _value) external override returns (bool) {
address spender = msg.sender;
uint96 spenderAllowance = allowances[_from][spender];
uint96 amount96 = safe96(_value, "IchiV2.approve: amount exceeds 96 bits");
if (spender != _from && spenderAllowance != uint96(-1)) {
uint96 newAllowance = sub96(spenderAllowance, amount96, "IchiV2.transferFrom: transfer amount exceeds spender allowance");
allowances[_from][spender] = newAllowance;
emit Approval(_from, spender, uint256(newAllowance));
}
_transferTokens(_from, _to, amount96);
return true;
}
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) public override {
return _delegate(msg.sender, delegatee);
}
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(address delegatee, uint256 nonce, uint256 expiry, uint8 v, bytes32 r, bytes32 s) public override {
bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR(), structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != NULL_ADDRESS, "IchiV2.delegateBySig: invalid signature");
require(nonce == nonces[signatory]++, "IchiV2.delegateBySig: invalid nonce");
require(block.timestamp <= expiry, "IchiV2.delegateBySig: signature expired");
return _delegate(signatory, delegatee);
}
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view override returns (uint96) {
uint32 nCheckpoints = numCheckpoints[account];
return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
}
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint256 blockNumber) public view override returns (uint96) {
require(blockNumber < block.number, "IchiV2.getPriorVotes: not yet determined");
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance
if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance
if (checkpoints[account][0].fromBlock > blockNumber) {
return 0;
}
uint32 lower = 0;
uint32 upper = nCheckpoints - 1;
while (upper > lower) {
uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
Checkpoint memory cp = checkpoints[account][center];
if (cp.fromBlock == blockNumber) {
return cp.votes;
} else if (cp.fromBlock < blockNumber) {
lower = center;
} else {
upper = center - 1;
}
}
return checkpoints[account][lower].votes;
}
/**
* @notice Delegate votes from `delegator` to `delegatee`
* @param delegator The address of the delegator
* @param delegatee The address to delegate votes to
*/
function _delegate(address delegator, address delegatee) internal {
address currentDelegate = delegates[delegator];
uint96 delegatorBalance = balances[delegator];
delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
_moveDelegates(currentDelegate, delegatee, delegatorBalance);
}
/**
* @notice Transfer `amount` tokens from `src` to `dst`
* @param src The address of the source account
* @param dst The address of the destination account
* @param amount The number of tokens to transfer
*/
function _transferTokens(address src, address dst, uint96 amount) internal {
require(src != NULL_ADDRESS, "IchiV2._transferTokens: cannot transfer from the zero address");
require(dst != NULL_ADDRESS, "IchiV2._transferTokens: cannot transfer to the zero address");
balances[src] = sub96(balances[src], amount, "IchiV2._transferTokens: transfer amount exceeds balance");
balances[dst] = add96(balances[dst], amount, "IchiV2._transferTokens: transfer amount overflows");
emit Transfer(src, dst, amount);
_moveDelegates(delegates[src], delegates[dst], amount);
}
/**
* @notice Move delegate votes from `delegator` to `delegatee`
* @param srcRep The address of the delegator
* @param dstRep The address to delegate votes to
* @param amount The number of tokens to delegate
*/
function _moveDelegates(address srcRep, address dstRep, uint96 amount) internal {
if (srcRep != dstRep && amount > 0) {
if (srcRep != NULL_ADDRESS) {
uint32 srcRepNum = numCheckpoints[srcRep];
uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
uint96 srcRepNew = sub96(srcRepOld, amount, "IchiV2._moveVotes: vote amount underflows");
_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
}
if (dstRep != NULL_ADDRESS) {
uint32 dstRepNum = numCheckpoints[dstRep];
uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
uint96 dstRepNew = add96(dstRepOld, amount, "IchiV2._moveVotes: vote amount overflows");
_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
}
}
}
/**
* @notice Create new votes checkpoint for a `delegatee`
* @param delegatee The address of the delegatee
* @param nCheckpoints Current number of checkpoints for the `delegatee`
* @param oldVotes Old number of votes
* @param newVotes New number of votes
*/
function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint96 oldVotes, uint96 newVotes) internal {
uint32 blockNumber = safe32(block.number, "IchiV2._writeCheckpoint: block number exceeds 32 bits");
if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, uint256(oldVotes), uint256(newVotes));
}
/**
* @notice safe conversion to uint32
* @param n number to convert
* @param errorMessage error raised during the conversion
* @return converted unit32 number
*/
function safe32(uint256 n, string memory errorMessage) internal pure returns (uint32) {
require(n < 2**32, errorMessage);
return uint32(n);
}
/**
* @notice safe conversion to uint96
* @param n number to convert
* @param errorMessage error raised during the conversion
* @return converted unit96 number
*/
function safe96(uint256 n, string memory errorMessage) internal pure returns (uint96) {
require(n < 2**96, errorMessage);
return uint96(n);
}
/**
* @notice safe addition for uint96
* @param a number to add
* @param b number to add
* @param errorMessage error raised during the conversion
* @return the result of the addition
*/
function add96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
uint96 c = a + b;
require(c >= a, errorMessage);
return c;
}
/**
* @notice safe subtraction for uint96
* @param a initial number
* @param b number to subtract
* @param errorMessage error raised during the conversion
* @return the result of the subtraction
*/
function sub96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
require(b <= a, errorMessage);
return a - b;
}
/**
* @notice returns the chain ID
* @return chain ID
*/
function getChainId() internal pure returns (uint256) {
uint256 chainId;
assembly { chainId := chainid() }
return chainId;
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.7.6;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/drafts/IERC20Permit.sol";
interface IIchiV2 is IERC20, IERC20Permit {
// EIP-20 token name for this token
function name() external view returns(string memory);
// EIP-20 token symbol for this token
function symbol() external view returns(string memory);
// EIP-20 token decimals for this token
function decimals() external view returns(uint8);
// ICHI V1 address
function ichiV1() external view returns(address);
// Address which may mint inflationary tokens
function minter() external view returns(address);
// The timestamp after which inflationary minting may occur
function mintingAllowedAfter() external view returns(uint256);
// Minimum time between inflationary mints
function minimumTimeBetweenMints() external view returns(uint32);
// Cap on the percentage of totalSupply that can be minted at each inflationary mint
function mintCap() external view returns(uint8);
// ICHI V2 to ICHI V1 conversion fee (default is 0%)
function conversionFee() external view returns(uint256);
// A record of each accounts delegate
function delegates(address) external view returns(address);
// A record of votes checkpoints for each account, by index
function checkpoints(address, uint32) external view returns(uint32, uint96);
// The number of checkpoints for each account
function numCheckpoints(address) external view returns(uint32);
// The EIP-712 typehash for the contract's domain
function DOMAIN_TYPEHASH() external view returns(bytes32);
// The EIP-712 typehash for the delegation struct used by the contract
function DELEGATION_TYPEHASH() external view returns(bytes32);
// The EIP-712 typehash for the permit struct used by the contract
function PERMIT_TYPEHASH() external view returns(bytes32);
// An event thats emitted when the minter address is changed
event MinterChanged(address minter, address newMinter);
// An event thats emitted when an account changes its delegate
event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);
// An event thats emitted when a delegate account's vote balance changes
event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);
// An event thats emitted when ICHI V1 tokens are converted into ICHI V2 tokens
event ConvertedToV2(address indexed from, uint256 amountIn, uint256 amountOut);
// An event thats emitted when ICHI V2 tokens are converted into ICHI V1 tokens
event ConvertedToV1(address indexed from, uint256 amountIn, uint256 amountOut);
// An event thats emitted when the conversion fee is changed
event ConversionFeeChanged(address minter, uint256 fee);
/**
* @notice Change the minter address
* @param minter_ The address of the new minter
*/
function setMinter(address minter_) external;
/**
* @notice Mint new tokens
* @param dst The address of the destination account
* @param rawAmount The number of tokens to be minted
*/
function mint(address dst, uint256 rawAmount) external;
/**
* @notice Change the ICHI V2 to ICHI V1 conversion fee
* @param fee_ New conversion fee
*/
function setConversionFee(uint256 fee_) external;
/**
* @notice Convert ICHI V1 tokens to ICHI V2 tokens
* @param rawAmount The number of ICHI V1 tokens to be converted (using 9 decimals representation)
*/
function convertToV2(uint256 rawAmount) external;
/**
* @notice Convert ICHI V2 tokens back to ICHI V1 tokens
* @param rawAmount The number of ICHI V2 tokens to be converted (using 18 decimals representation)
*/
function convertToV1(uint256 rawAmount) external;
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) external;
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(address delegatee, uint256 nonce, uint256 expiry, uint8 v, bytes32 r, bytes32 s) external;
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view returns (uint96);
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint256 blockNumber) external view returns (uint96);
}