The contract "X7R" is an ERC20 token that allows for token transfers with fees and integrates with a liquidity hub and discount authority. It includes features such as setting fee ratios, defining AMM pairs, and enabling/disabling transfers.
The ILiquidityHub interface defines a function processFees that processes fees for a given address. The IDiscountAuthority interface defines a function discountRatio that returns the discount ratio for a given address, represented by two uint256 values.
IDiscountAuthoritypublic discountAuthority;ILiquidityHubpublic liquidityHub;mapping(address=> bool)public ammPair;address public offRampPair;// max 7% feeuint256 public maxFeeNumerator =700;// 6 % feeuint256 public feeNumerator =600;uint256 public feeDenominator =10000;bool discountAuthorityFrozen;bool liquidityHubFrozen;bool transfersEnabled;
The contract has public variables discountAuthority and liquidityHub of types IDiscountAuthority and ILiquidityHub, respectively. It also includes a mapping ammPair that maps addresses to boolean values, representing whether an address is an automated market maker (AMM) pair. The contract has an offRampPair variable to store an address.
There are additional public variables maxFeeNumerator, feeNumerator, and feeDenominator to control the fee calculation. The contract also includes boolean variables discountAuthorityFrozen, liquidityHubFrozen, and transfersEnabled to track certain states related to discount authority, liquidity hub, and transfers.
The constructor of the contract initializes the discountAuthority and liquidityHub variables with the provided addresses. It also sets the contract name and symbol to "X7R" using the ERC20 constructor and sets the contract owner to the address 0x7000a09c425ABf5173FF458dF1370C25d1C58105 using the Ownable constructor. Additionally, it mints 100,000,000 * 10¹⁸ X7R tokens to the address 0x7000a09c425ABf5173FF458dF1370C25d1C58105.
The setLiquidityHub function allows the owner of the contract to set the address of the liquidity hub. It requires that the liquidity hub address is not frozen (liquidityHubFrozen is false). Once the new address is set, the function emits the LiquidityHubSet event with the updated liquidity hub address.
The setDiscountAuthority function allows the owner of the contract to set the address of the discount authority. It requires that the discount authority address is not frozen (discountAuthorityFrozen is false). Once the new address is set, the function emits the DiscountAuthoritySet event with the updated discount authority address.
The setFeeNumerator function allows the owner of the contract to set the fee numerator value. It requires that the new fee numerator does not exceed the maximum fee numerator (feeNumerator_ <= maxFeeNumerator). Once the new fee numerator is set, the function emits the FeeNumeratorSet event with the updated fee numerator value.
The setAMM function allows the owner of the contract to set whether an address represents an Automated Market Maker (AMM) pair. It takes an ammAddress and a boolean isAMM as parameters. It updates the ammPair mapping with the given address and its associated AMM status. The function emits the AMMSet event with the updated AMM pair address and its corresponding boolean value.
The setOffRampPair function allows the owner of the contract to set the address of the off-ramp pair. It takes an ammAddress parameter representing the off-ramp pair address and updates the offRampPair variable with this value. The function emits the OffRampPairSet event with the updated off-ramp pair address.
The freezeLiquidityHub function allows the owner of the contract to freeze the liquidity hub address. It requires that the liquidity hub address is not already frozen (liquidityHubFrozen is false). If the condition is met, it sets the liquidityHubFrozen variable to true, indicating that the liquidity hub address is now frozen. The function emits the LiquidityHubFrozen event to signal the freezing of the liquidity hub address.
The freezeDiscountAuthority function allows the owner of the contract to freeze the discount authority address. It requires that the discount authority address is not already frozen (discountAuthorityFrozen is false). If the condition is met, it sets the discountAuthorityFrozen variable to true, indicating that the discount authority address is now frozen. The function emits the DiscountAuthorityFrozen event to signal the freezing of the discount authority address.
The circulatingSupply function is a view function that returns the circulating supply of the token. It calculates the circulating supply by subtracting the balance of the zero address (address(0)) and the balance of the dead address (address(0x000000000000000000000000000000000000dEaD)) from the total supply of the token (totalSupply()).
The enableTrading function allows the owner of the contract to enable token transfers. It requires that transfers are currently disabled (transfersEnabled is false). If the condition is met, it sets the transfersEnabled variable to true, indicating that token transfers are now enabled.
The _transfer function is an internal override function from the ERC20 contract. It handles the logic for token transfers with additional features.
It checks if transfers are enabled or if the transfer is initiated by the owner. If transfers are disabled and the sender is not the owner, the function will revert.
It initializes a variable transferAmount with the original transfer amount (amount).
If the sender or recipient address is the liquidity hub, the function calls the _transfer function from the ERC20 contract to execute the transfer and returns.
If the sender or recipient is identified as an AMM pair based on the ammPair mapping, additional fee calculations are performed.
The effective principal address is determined based on whether the recipient is an AMM pair or not.
The discountRatio function from the discount authority contract is called to retrieve the fee modifier numerator and denominator for the effective principal address.
If the fee modifier numerator is greater than the denominator or the denominator is zero, the fee modifier values are set to 1 to avoid invalid calculations.
The fee amount is calculated based on the fee numerator, fee modifier numerator, and fee denominator.
The fee amount is transferred to the liquidity hub address using the _transfer function.
The transferAmount is updated to reflect the amount minus the fee.
If the recipient address matches the off-ramp pair, the processFees function is called on the liquidity hub contract to process the fees for the current contract.
Finally, the remaining transferAmount is transferred to the recipient address using the _transfer function.
This function provides additional functionality for fee calculations, AMM pair handling, and integration with the liquidity hub contract during token transfers.
The rescueETH function allows anyone to transfer any Ether (ETH) held by the contract to the liquidity hub address. It uses the payable keyword to indicate that the contract can receive Ether. It calls the call function on the liquidity hub address with the Ether value as address(this).balance. The success variable captures the success status of the call. If the call is successful, it proceeds without any action. If the call fails, the function reverts the transaction with a require statement.
The rescueTokens function allows anyone to transfer any ERC20 tokens held by the contract to the liquidity hub address. It takes a tokenAddress parameter representing the address of the ERC20 token. It transfers the balance of the ERC20 token held by the contract (IERC20(tokenAddress).balanceOf(address(this))) to the liquidity hub address using the transfer function from the ERC20 token contract (IERC20(tokenAddress)).
