79 lines
2.7 KiB
Solidity
79 lines
2.7 KiB
Solidity
// SPDX-License-Identifier: MIT
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pragma solidity 0.8.19;
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/**
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* @title DurianUSDT
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* @dev Fixed supply ERC-20 token - NO MINTING CAPABILITY
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* Total Supply: 1,000,000,000,000 (1 Trillion) tokens with 6 decimals (matching USDT)
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*
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* IMPORTANT: This contract has NO mint function and NO way to increase supply.
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* All tokens are minted to the deployer at construction time.
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*/
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contract DurianUSDT {
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string public constant name = "Durian USDT";
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string public constant symbol = "dUSDT";
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uint8 public constant decimals = 6;
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// Fixed total supply: 1 trillion tokens (1,000,000,000,000 * 10^6)
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uint256 public constant totalSupply = 1_000_000_000_000 * 10**6;
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mapping(address => uint256) private _balances;
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mapping(address => mapping(address => uint256)) private _allowances;
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event Transfer(address indexed from, address indexed to, uint256 value);
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event Approval(address indexed owner, address indexed spender, uint256 value);
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/**
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* @dev Constructor - mints entire fixed supply to deployer
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* No mint function exists - supply is permanently fixed
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*/
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constructor() {
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_balances[msg.sender] = totalSupply;
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emit Transfer(address(0), msg.sender, totalSupply);
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}
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function balanceOf(address account) public view returns (uint256) {
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return _balances[account];
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}
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function transfer(address to, uint256 amount) public returns (bool) {
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require(to != address(0), "Transfer to zero address");
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require(_balances[msg.sender] >= amount, "Insufficient balance");
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unchecked {
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_balances[msg.sender] -= amount;
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_balances[to] += amount;
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}
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emit Transfer(msg.sender, to, amount);
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return true;
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}
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function allowance(address owner, address spender) public view returns (uint256) {
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return _allowances[owner][spender];
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}
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function approve(address spender, uint256 amount) public returns (bool) {
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require(spender != address(0), "Approve to zero address");
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_allowances[msg.sender][spender] = amount;
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emit Approval(msg.sender, spender, amount);
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return true;
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}
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function transferFrom(address from, address to, uint256 amount) public returns (bool) {
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require(from != address(0), "Transfer from zero address");
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require(to != address(0), "Transfer to zero address");
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require(_balances[from] >= amount, "Insufficient balance");
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require(_allowances[from][msg.sender] >= amount, "Insufficient allowance");
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unchecked {
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_balances[from] -= amount;
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_balances[to] += amount;
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_allowances[from][msg.sender] -= amount;
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}
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emit Transfer(from, to, amount);
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return true;
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}
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}
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