Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_setOwner(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "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 onlyOwner {
_setOwner(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 onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @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 ^0.8.0;
/**
* @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;
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");
(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");
(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");
(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");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal 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
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;
/**
* @title Governance token interface.
*/
interface IGovernanceToken {
/// @notice A checkpoint for marking number of votes as of a given block.
struct Checkpoint {
// The 32-bit unsigned integer is valid until these estimated dates for these given chains:
// - BSC: Sat Dec 23 2428 18:23:11 UTC
// - ETH: Tue Apr 18 3826 09:27:12 UTC
// This assumes that block mining rates don't speed up.
uint32 blockNumber;
// This type is set to `uint224` for optimizations purposes (i.e., specifically to fit in a 32-byte block). It
// assumes that the number of votes for the implementing governance token never exceeds the maximum value for a
// 224-bit number.
uint224 votes;
}
/**
* @notice Determine the 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 getVotesAtBlock(address account, uint32 blockNumber) external view returns (uint224);
/// @notice Emitted whenever a new delegate is set for an account.
event DelegateChanged(address indexed delegator, address currentDelegate, address newDelegate);
/// @notice Emitted when a delegate's vote count changes.
event DelegateVotesChanged(address indexed delegatee, uint224 oldVotes, uint224 newVotes);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "./governance/IGovernanceToken.sol";
import "./tax/ITaxHandler.sol";
import "./treasury/ITreasuryHandler.sol";
/**
* @title Tokenfi token contract
* @dev The Tokenfi token has modular systems for tax and treasury handler as well as governance capabilities.
*/
contract T1 is IERC20, IGovernanceToken, Ownable {
using Address for address payable;
/// @dev Registry of user token balances.
mapping(address => uint256) private _balances;
/// @dev Registry of addresses users have given allowances to.
mapping(address => mapping(address => uint256)) private _allowances;
/// @notice Registry of user delegates for governance.
mapping(address => address) public delegates;
/// @notice Registry of nonces for vote delegation.
mapping(address => uint256) public nonces;
/// @notice Registry of the number of balance checkpoints an account has.
mapping(address => uint32) public numCheckpoints;
/// @notice Registry of balance checkpoints per account.
mapping(address => mapping(uint32 => Checkpoint)) public checkpoints;
/// @notice The EIP-712 typehash for the contract's domain.
bytes32 public constant DOMAIN_TYPEHASH =
keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
/// @notice The EIP-712 typehash for the delegation struct used by the contract.
bytes32 public constant DELEGATION_TYPEHASH =
keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");
/// @notice The contract implementing tax calculations.
ITaxHandler public taxHandler;
/// @notice The contract that performs treasury-related operations.
ITreasuryHandler public treasuryHandler;
/// @notice Emitted when the tax handler contract is changed.
event TaxHandlerChanged(address oldAddress, address newAddress);
/// @notice Emitted when the treasury handler contract is changed.
event TreasuryHandlerChanged(address oldAddress, address newAddress);
/// @dev Name of the token.
string private _name;
/// @dev Symbol of the token.
string private _symbol;
/**
* @param name_ Name of the token.
* @param symbol_ Symbol of the token.
* @param taxHandlerAddress Initial tax handler contract.
* @param treasuryHandlerAddress Initial treasury handler contract.
*/
constructor(
string memory name_,
string memory symbol_,
address taxHandlerAddress,
address treasuryHandlerAddress
) {
_name = name_;
_symbol = symbol_;
taxHandler = ITaxHandler(taxHandlerAddress);
treasuryHandler = ITreasuryHandler(treasuryHandlerAddress);
_balances[_msgSender()] = totalSupply();
emit Transfer(address(0), _msgSender(), totalSupply());
}
/**
* @notice Get token name.
* @return Name of the token.
*/
function name() public view returns (string memory) {
return _name;
}
/**
* @notice Get token symbol.
* @return Symbol of the token.
*/
function symbol() external view returns (string memory) {
return _symbol;
}
/**
* @notice Get number of decimals used by the token.
* @return Number of decimals used by the token.
*/
function decimals() external pure returns (uint8) {
return 9;
}
/**
* @notice Get the maximum number of tokens.
* @return The maximum number of tokens that will ever be in existence.
*/
function totalSupply() public pure override returns (uint256) {
// Five billion, i.e., 5,000,000,000 tokens.
return 5e9 * 1e9;
}
/**
* @notice Get token balance of given account.
* @param account Address to retrieve balance for.
* @return The number of tokens owned by `account`.
*/
function balanceOf(address account) external view override returns (uint256) {
return _balances[account];
}
/**
* @notice Transfer tokens from caller's address to another.
* @param recipient Address to send the caller's tokens to.
* @param amount The number of tokens to transfer to recipient.
* @return True if transfer succeeds, else an error is raised.
*/
function transfer(address recipient, uint256 amount) external override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @notice Get the allowance `owner` has given `spender`.
* @param owner The address on behalf of whom tokens can be spent by `spender`.
* @param spender The address authorized to spend tokens on behalf of `owner`.
* @return The allowance `owner` has given `spender`.
*/
function allowance(address owner, address spender) external view override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @notice Approve address to spend caller's tokens.
* @dev This method can be exploited by malicious spenders if their allowance is already non-zero. See the following
* document for details: https://docs.google.com/document/d/1YLPtQxZu1UAvO9cZ1O2RPXBbT0mooh4DYKjA_jp-RLM/edit.
* Ensure the spender can be trusted before calling this method if they've already been approved before. Otherwise
* use either the `increaseAllowance`/`decreaseAllowance` functions, or first set their allowance to zero, before
* setting a new allowance.
* @param spender Address to authorize for token expenditure.
* @param amount The number of tokens `spender` is allowed to spend.
* @return True if the approval succeeds, else an error is raised.
*/
function approve(address spender, uint256 amount) external override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @notice Transfer tokens from one address to another.
* @param sender Address to move tokens from.
* @param recipient Address to send the caller's tokens to.
* @param amount The number of tokens to transfer to recipient.
* @return True if the transfer succeeds, else an error is raised.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external override returns (bool) {
_transfer(sender, recipient, amount);
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(
currentAllowance >= amount,
"FLOKI:transferFrom:ALLOWANCE_EXCEEDED: Transfer amount exceeds allowance."
);
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}
return true;
}
/**
* @notice Increase spender's allowance.
* @param spender Address of user authorized to spend caller's tokens.
* @param addedValue The number of tokens to add to `spender`'s allowance.
* @return True if the allowance is successfully increased, else an error is raised.
*/
function increaseAllowance(address spender, uint256 addedValue) external returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
return true;
}
/**
* @notice Decrease spender's allowance.
* @param spender Address of user authorized to spend caller's tokens.
* @param subtractedValue The number of tokens to remove from `spender`'s allowance.
* @return True if the allowance is successfully decreased, else an error is raised.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(
currentAllowance >= subtractedValue,
"FLOKI:decreaseAllowance:ALLOWANCE_UNDERFLOW: Subtraction results in sub-zero allowance."
);
unchecked {
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @notice Delegate votes to given address.
* @dev It should be noted that users that want to vote themselves, also need to call this method, albeit with their
* own address.
* @param delegatee Address to delegate votes to.
*/
function delegate(address delegatee) external {
return _delegate(msg.sender, delegatee);
}
/**
* @notice Delegate 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 {
bytes32 domainSeparator = keccak256(
abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), block.chainid, address(this))
);
bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), "FLOKI:delegateBySig:INVALID_SIGNATURE: Received signature was invalid.");
require(block.timestamp <= expiry, "FLOKI:delegateBySig:EXPIRED_SIGNATURE: Received signature has expired.");
require(nonce == nonces[signatory]++, "FLOKI:delegateBySig:INVALID_NONCE: Received nonce was invalid.");
return _delegate(signatory, delegatee);
}
/**
* @notice Determine the 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 getVotesAtBlock(address account, uint32 blockNumber) public view returns (uint224) {
require(
blockNumber < block.number,
"FLOKI:getVotesAtBlock:FUTURE_BLOCK: Cannot get votes at a block in the future."
);
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance.
if (checkpoints[account][nCheckpoints - 1].blockNumber <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance.
if (checkpoints[account][0].blockNumber > blockNumber) {
return 0;
}
// Perform binary search.
uint32 lowerBound = 0;
uint32 upperBound = nCheckpoints - 1;
while (upperBound > lowerBound) {
uint32 center = upperBound - (upperBound - lowerBound) / 2;
Checkpoint memory checkpoint = checkpoints[account][center];
if (checkpoint.blockNumber == blockNumber) {
return checkpoint.votes;
} else if (checkpoint.blockNumber < blockNumber) {
lowerBound = center;
} else {
upperBound = center - 1;
}
}
// No exact block found. Use last known balance before that block number.
return checkpoints[account][lowerBound].votes;
}
/**
* @notice Set new tax handler contract.
* @param taxHandlerAddress Address of new tax handler contract.
*/
function setTaxHandler(address taxHandlerAddress) external onlyOwner {
address oldTaxHandlerAddress = address(taxHandler);
taxHandler = ITaxHandler(taxHandlerAddress);
emit TaxHandlerChanged(oldTaxHandlerAddress, taxHandlerAddress);
}
/**
* @notice Set new treasury handler contract.
* @param treasuryHandlerAddress Address of new treasury handler contract.
*/
function setTreasuryHandler(address treasuryHandlerAddress) external onlyOwner {
address oldTreasuryHandlerAddress = address(treasuryHandler);
treasuryHandler = ITreasuryHandler(treasuryHandlerAddress);
emit TreasuryHandlerChanged(oldTreasuryHandlerAddress, treasuryHandlerAddress);
}
/**
* @notice Send any tokens or ETH stuck in the token contract to the treasury handler.
* @param tokenAddress Address of the token to withdraw. If set to the zero address, ETH will be withdrawn.
* @param amount The number of tokens to withdraw.
* @dev The treasury handler has a method to send any tokens to the treasury (except for what it uses to swap).
*/
function withdraw(address tokenAddress, uint256 amount) external onlyOwner {
if (tokenAddress == address(0)) {
payable(address(treasuryHandler)).sendValue(amount);
} else {
IERC20(tokenAddress).transferFrom(address(this), address(treasuryHandler), amount);
}
}
/**
* @notice Delegate votes from one address to another.
* @param delegator Address from which to delegate votes for.
* @param delegatee Address to delegate votes to.
*/
function _delegate(address delegator, address delegatee) private {
address currentDelegate = delegates[delegator];
uint256 delegatorBalance = _balances[delegator];
delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
_moveDelegates(currentDelegate, delegatee, uint224(delegatorBalance));
}
/**
* @notice Move delegates from one address to another.
* @param from Representative to move delegates from.
* @param to Representative to move delegates to.
* @param amount Number of delegates to move.
*/
function _moveDelegates(
address from,
address to,
uint224 amount
) private {
// No need to update checkpoints if the votes don't actually move between different delegates. This can be the
// case where tokens are transferred between two parties that have delegated their votes to the same address.
if (from == to) {
return;
}
// Some users preemptively delegate their votes (i.e. before they have any tokens). No need to perform an update
// to the checkpoints in that case.
if (amount == 0) {
return;
}
if (from != address(0)) {
uint32 fromRepNum = numCheckpoints[from];
uint224 fromRepOld = fromRepNum > 0 ? checkpoints[from][fromRepNum - 1].votes : 0;
uint224 fromRepNew = fromRepOld - amount;
_writeCheckpoint(from, fromRepNum, fromRepOld, fromRepNew);
}
if (to != address(0)) {
uint32 toRepNum = numCheckpoints[to];
uint224 toRepOld = toRepNum > 0 ? checkpoints[to][toRepNum - 1].votes : 0;
uint224 toRepNew = toRepOld + amount;
_writeCheckpoint(to, toRepNum, toRepOld, toRepNew);
}
}
/**
* @notice Write balance checkpoint to chain.
* @param delegatee The address to write the checkpoint for.
* @param nCheckpoints The number of checkpoints `delegatee` already has.
* @param oldVotes Number of votes prior to this checkpoint.
* @param newVotes Number of votes `delegatee` now has.
*/
function _writeCheckpoint(
address delegatee,
uint32 nCheckpoints,
uint224 oldVotes,
uint224 newVotes
) private {
uint32 blockNumber = uint32(block.number);
if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].blockNumber == blockNumber) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
}
/**
* @notice Approve spender on behalf of owner.
* @param owner Address on behalf of whom tokens can be spent by `spender`.
* @param spender Address to authorize for token expenditure.
* @param amount The number of tokens `spender` is allowed to spend.
*/
function _approve(
address owner,
address spender,
uint256 amount
) private {
require(owner != address(0), "FLOKI:_approve:OWNER_ZERO: Cannot approve for the zero address.");
require(spender != address(0), "FLOKI:_approve:SPENDER_ZERO: Cannot approve to the zero address.");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @notice Transfer `amount` tokens from account `from` to account `to`.
* @param from Address the tokens are moved out of.
* @param to Address the tokens are moved to.
* @param amount The number of tokens to transfer.
*/
function _transfer(
address from,
address to,
uint256 amount
) private {
require(from != address(0), "FLOKI:_transfer:FROM_ZERO: Cannot transfer from the zero address.");
require(to != address(0), "FLOKI:_transfer:TO_ZERO: Cannot transfer to the zero address.");
require(amount > 0, "FLOKI:_transfer:ZERO_AMOUNT: Transfer amount must be greater than zero.");
require(amount <= _balances[from], "FLOKI:_transfer:INSUFFICIENT_BALANCE: Transfer amount exceeds balance.");
treasuryHandler.beforeTransferHandler(from, to, amount);
uint256 tax = taxHandler.getTax(from, to, amount);
uint256 taxedAmount = amount - tax;
_balances[from] -= amount;
_balances[to] += taxedAmount;
_moveDelegates(delegates[from], delegates[to], uint224(taxedAmount));
if (tax > 0) {
_balances[address(treasuryHandler)] += tax;
_moveDelegates(delegates[from], delegates[address(treasuryHandler)], uint224(tax));
emit Transfer(from, address(treasuryHandler), tax);
}
treasuryHandler.afterTransferHandler(from, to, amount);
emit Transfer(from, to, taxedAmount);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;
/**
* @title Tax handler interface
* @dev Any class that implements this interface can be used for protocol-specific tax calculations.
*/
interface ITaxHandler {
/**
* @notice Get number of tokens to pay as tax.
* @param benefactor Address of the benefactor.
* @param beneficiary Address of the beneficiary.
* @param amount Number of tokens in the transfer.
* @return Number of tokens to pay as tax.
*/
function getTax(
address benefactor,
address beneficiary,
uint256 amount
) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;
/**
* @title Treasury handler interface
* @dev Any class that implements this interface can be used for protocol-specific operations pertaining to the treasury.
*/
interface ITreasuryHandler {
/**
* @notice Perform operations before a transfer is executed.
* @param benefactor Address of the benefactor.
* @param beneficiary Address of the beneficiary.
* @param amount Number of tokens in the transfer.
*/
function beforeTransferHandler(
address benefactor,
address beneficiary,
uint256 amount
) external;
/**
* @notice Perform operations after a transfer is executed.
* @param benefactor Address of the benefactor.
* @param beneficiary Address of the beneficiary.
* @param amount Number of tokens in the transfer.
*/
function afterTransferHandler(
address benefactor,
address beneficiary,
uint256 amount
) external;
}