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LLA Token

LLA Token#

Contract Overview#

LLA Token is an upgradeable ERC20 token contract based on OpenZeppelin, supporting the following core functions:

  • Role-based Access Control: Manages ADMIN_ROLE, PAUSER_ROLE, MINTER_ROLE, UPGRADER_ROLE through AccessControl

  • Upgradeability: Implements secure upgrades through UUPS pattern

  • Token Pausability: Supports global pause/unpause of token transfers

  • Token Minting and Burning: Supports controlled minting and burning

  • Fixed Total Supply: Set total supply at 100,000,000 LLA

Core Variables and Configuration#

Role Definitions#

bytes32 public constant ADMIN_ROLE = keccak256("ADMIN_ROLE");
bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
bytes32 public constant UPGRADER_ROLE = keccak256("UPGRADER_ROLE");

Other Configurations#

string public constant version = "v1.0";
uint256 public constant TOTAL_SUPPLY = 100_0000_0000 * 1e18; // 100,000,000 LLA

Core Functions Explained#

1. Initialization Function#

function initialize(
    address defaultAdmin,
    address pauser,
    address minter,
    address upgrader
) public initializer {
    if (defaultAdmin == address(0)) revert InvalidAddress(defaultAdmin);
    // ... other address validations
    __ERC20_init("LLA", "LLA");
    __ERC20Burnable_init();
    __ERC20Pausable_init();
    __AccessControl_init();
    __UUPSUpgradeable_init();
    _grantRole(ADMIN_ROLE, defaultAdmin);
    _grantRole(PAUSER_ROLE, pauser);
    _grantRole(MINTER_ROLE, minter);
    _grantRole(UPGRADER_ROLE, upgrader);
}

  • Purpose: Initialize contract and assign roles

  • Key Points:

    • Validate all address legitimacy

    • Initialize parent contracts (ERC20, Access Control, Upgradeable)

    • Grant initial role permissions

2. Token Minting#

function mint(address to, uint256 amount) public onlyRole(MINTER_ROLE) {
    if (amount == 0) revert InvalidAmount(amount);
    if (to == address(0)) revert InvalidAddress(to);
    _mint(to, amount);
}

  • Purpose: Mint new tokens

  • Restrictions:

    • Only callable by MINTER_ROLE

    • Prevent minting to zero address or zero amount

3. Pause and Unpause#

function pause() public onlyRole(PAUSER_ROLE) {
    _pause();
}

function unpause() public onlyRole(PAUSER_ROLE) {
    _unpause();
}

  • Purpose: Global pause/unpause of token transfers

  • Impact:

    • No transfers or approvals during pause

4. Token Burning#

function burn(uint256 amount) public override {
    if (amount == 0) revert InvalidAmount(amount);
    _burn(msg.sender, amount);
}

  • Purpose: Burn user’s own tokens

  • Enhancement:

    • Validate burn amount is not zero

5. Upgrade Control#

function _authorizeUpgrade(
    address _newImplementation
) internal view override onlyRole(UPGRADER_ROLE) {
    if (_newImplementation == address(0)) revert InvalidAddress(_newImplementation);
}

  • Purpose: Authorize upgrade to new implementation contract

  • Restrictions:

    • Only callable by UPGRADER_ROLE

    • Prevent upgrade to zero address

6. Role Management#

function addRole(bytes32 role, address account) external onlyRole(ADMIN_ROLE) {
    _grantRole(role, account);
}

function revokeRole(bytes32 role, address account) public override onlyRole(ADMIN_ROLE) {
    _revokeRole(role, account);
}

  • Purpose: Admin management of role permissions

  • Permissions:

    • Only ADMIN_ROLE can add/revoke roles

7. Custom Errors#

error InvalidAddress(address addr);
error InvalidAmount(uint amount);

  • Usage: Enhance error message readability

Function Workflows#

Scenario: Minting and Distributing Tokens#

  1. Deploy contract and call initialize function:

LLAToken.initialize(admin, pauser, minter, upgrader);

  1. Call mint function to mint tokens:

LLAToken.mint(userAddress, 1000 * 1e18); // Mint 1000 LLA

Scenario: Pausing Token Trading#

  1. Call pause function to pause contract:

LLAToken.pause(); // Must be called by PAUSER_ROLE

  1. No transfers or approvals possible during pause

Events and Errors#

Events#

  • ERC20 Standard Events: Transfer, Approval

  • Access Control Events: RoleGranted, RoleRevoked

Errors#

error InvalidAddress(address addr);
error InvalidAmount(uint amount);
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