pragma solidity ^0.4.18;
/**
* @title ERC20 Token Interface
*/
contract ERC20 {
uint256 public totalSupply;
function balanceOf(address _owner) public view returns (uint256 balance);
function transfer(address _to, uint256 _value) public returns (bool success);
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);
function approve(address _spender, uint256 _value) public returns (bool success);
function allowance(address _owner, address _spender) public view returns (uint256 remaining);
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
/**
* @title ERC677 transferAndCall token interface
* @dev See https://github.com/ethereum/EIPs/issues/677 for specification and
* discussion.
*/
contract ERC677 {
event Transfer(address indexed _from, address indexed _to, uint256 _value, bytes _data);
function transferAndCall(address _to, uint _value, bytes _data) public returns (bool success);
}
/**
* @title Receiver interface for ERC677 transferAndCall
* @dev See https://github.com/ethereum/EIPs/issues/677 for specification and
* discussion.
*/
contract ERC677Receiver {
function tokenFallback(address _from, uint _value, bytes _data) public;
}
/**
* @title VALID Token
* @dev ERC20 compatible smart contract for the VALID token. Closely follows
* ConsenSys StandardToken.
*/
contract ValidToken is ERC677, ERC20 {
// token metadata
string public constant name = "VALID";
string public constant symbol = "VLD";
uint8 public constant decimals = 18;
// total supply and maximum amount of tokens
uint256 public constant maxSupply = 10**9 * 10**uint256(decimals);
// note: this equals 10**27, which is smaller than uint256 max value (~10**77)
// token accounting
mapping(address => uint256) balances;
mapping(address => mapping(address => uint256)) internal allowed;
// token lockups
mapping(address => uint256) lockups;
event TokensLocked(address indexed _holder, uint256 _timeout);
// ownership
address public owner;
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
// minting
bool public mintingDone = false;
modifier mintingFinished() {
require(mintingDone == true);
_;
}
modifier mintingInProgress() {
require(mintingDone == false);
_;
}
// constructor
function ValidToken() public {
owner = msg.sender;
}
/**
* @dev Allows the current owner to transfer the ownership.
* @param _newOwner The address to transfer ownership to.
*/
function transferOwnership(address _newOwner) public onlyOwner {
owner = _newOwner;
}
// minting functionality
function mint(address[] _recipients, uint256[] _amounts) public mintingInProgress onlyOwner {
require(_recipients.length == _amounts.length);
require(_recipients.length < 255);
for (uint8 i = 0; i < _recipients.length; i++) {
address recipient = _recipients[i];
uint256 amount = _amounts[i];
// enforce maximum token supply
require(totalSupply + amount >= totalSupply);
require(totalSupply + amount <= maxSupply);
balances[recipient] += amount;
totalSupply += amount;
Transfer(0, recipient, amount);
}
}
function lockTokens(address[] _holders, uint256[] _timeouts) public mintingInProgress onlyOwner {
require(_holders.length == _timeouts.length);
require(_holders.length < 255);
for (uint8 i = 0; i < _holders.length; i++) {
address holder = _holders[i];
uint256 timeout = _timeouts[i];
// make sure lockup period can not be overwritten
require(lockups[holder] == 0);
lockups[holder] = timeout;
TokensLocked(holder, timeout);
}
}
function finishMinting() public mintingInProgress onlyOwner {
// check hard cap again
assert(totalSupply <= maxSupply);
mintingDone = true;
}
// ERC20 functionality
function balanceOf(address _owner) public view returns (uint256) {
return balances[_owner];
}
function transfer(address _to, uint256 _value) public mintingFinished returns (bool) {
// prevent some common errors
require(_to != address(0x0));
require(_to != address(this));
// check lockups
if (lockups[msg.sender] != 0) {
require(now >= lockups[msg.sender]);
}
// check balance
require(balances[msg.sender] >= _value);
assert(balances[_to] + _value >= balances[_to]); // receiver balance overflow check
balances[msg.sender] -= _value;
balances[_to] += _value;
Transfer(msg.sender, _to, _value);
return true;
}
function transferFrom(address _from, address _to, uint256 _value) public mintingFinished returns (bool) {
// prevent some common errors
require(_to != address(0x0));
require(_to != address(this));
// check lockups
if (lockups[_from] != 0) {
require(now >= lockups[_from]);
}
// check balance and allowance
uint256 allowance = allowed[_from][msg.sender];
require(balances[_from] >= _value);
require(allowance >= _value);
assert(balances[_to] + _value >= balances[_to]); // receiver balance overflow check
allowed[_from][msg.sender] -= _value;
balances[_from] -= _value;
balances[_to] += _value;
Transfer(_from, _to, _value);
return true;
}
function approve(address _spender, uint256 _value) public returns (bool) {
// no check for zero allowance, see NOTES.md
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
return true;
}
function allowance(address _owner, address _spender) public view returns (uint256) {
return allowed[_owner][_spender];
}
// ERC677 functionality
function transferAndCall(address _to, uint _value, bytes _data) public mintingFinished returns (bool) {
require(transfer(_to, _value));
Transfer(msg.sender, _to, _value, _data);
// call receiver
if (isContract(_to)) {
ERC677Receiver receiver = ERC677Receiver(_to);
receiver.tokenFallback(msg.sender, _value, _data);
}
return true;
}
function isContract(address _addr) private view returns (bool) {
uint len;
assembly {
len := extcodesize(_addr)
}
return len > 0;
}
}
{
"compilationTarget": {
"ValidToken.sol": "ValidToken"
},
"evmVersion": "byzantium",
"libraries": {},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}
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