Contract Source Code:
File 1 of 1 : RotoToken
pragma solidity 0.4.24;
/**
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
/**
* @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
/**
* @dev Adds two numbers, throws on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
c = a + b;
assert(c >= a);
return c;
}
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20 {
function allowance(address owner, address spender) public view returns (uint256);
function transferFrom(address from, address to, uint256 value) public returns (bool);
function approve(address spender, uint256 value) public returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 value);
function totalSupply() public view returns (uint256);
function balanceOf(address who) public view returns (uint256);
function transfer(address to, uint256 value) public returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
}
/**
* @title Standard ERC20 token
*
* @dev Implementation of the basic standard token.
* @dev https://github.com/ethereum/EIPs/issues/20
* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*/
contract StandardToken is ERC20 {
using SafeMath for uint256;
mapping(address => uint256) balances;
uint256 totalSupply_;
mapping (address => mapping (address => uint256)) internal allowed;
/**
* @dev Transfer tokens from one address to another
* @param _from address The address which you want to send tokens from
* @param _to address The address which you want to transfer to
* @param _value uint256 the amount of tokens to be transferred
*/
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
require(_to != address(0));
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
emit Transfer(_from, _to, _value);
return true;
}
/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
*
* 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
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint256 _value) public returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
* @param _owner address The address which owns the funds.
* @param _spender address The address which will spend the funds.
* @return A uint256 specifying the amount of tokens still available for the spender.
*/
function allowance(address _owner, address _spender) public view returns (uint256) {
return allowed[_owner][_spender];
}
/**
* @dev Increase the amount of tokens that an owner allowed to a spender.
*
* approve should be called when allowed[_spender] == 0. To increment
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* @param _spender The address which will spend the funds.
* @param _addedValue The amount of tokens to increase the allowance by.
*/
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
/**
* @dev Decrease the amount of tokens that an owner allowed to a spender.
*
* approve should be called when allowed[_spender] == 0. To decrement
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* @param _spender The address which will spend the funds.
* @param _subtractedValue The amount of tokens to decrease the allowance by.
*/
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
/**
* @dev total number of tokens in existence
*/
function totalSupply() public view returns (uint256) {
return totalSupply_;
}
/**
* @dev transfer token for a specified address
* @param _to The address to transfer to.
* @param _value The amount to be transferred.
*/
function transfer(address _to, uint256 _value) public returns (bool) {
require(_to != address(0));
require(_value <= balances[msg.sender]);
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}
/**
* @dev Gets the balance of the specified address.
* @param _owner The address to query the the balance of.
* @return An uint256 representing the amount owned by the passed address.
*/
function balanceOf(address _owner) public view returns (uint256 balance) {
return balances[_owner];
}
}
contract RotoToken is StandardToken {
string public constant name = "Roto"; // token name
string public constant symbol = "ROTO"; // token symbol
uint8 public constant decimals = 18; // token decimal
uint256 public constant INITIAL_SUPPLY = 21000000 * (10 ** uint256(decimals));
address owner;
address roto = this;
address manager;
// keeps track of the ROTO currently staked in a tournament
// the format is user address -> the tournament they staked in -> how much they staked
mapping (address => mapping (bytes32 => uint256)) stakes;
uint256 owner_transfer = 2000000 * (10** uint256(decimals));
/**
* @dev Constructor that gives msg.sender all of existing tokens.
*/
modifier onlyOwner {
require(msg.sender==owner);
_;
}
modifier onlyManager {
require(msg.sender==manager);
_;
}
event ManagerChanged(address _contract);
event RotoStaked(address _user, uint256 stake);
event RotoReleased(address _user, uint256 stake);
event RotoDestroyed(address _user, uint256 stake);
event RotoRewarded(address _contract, address _user, uint256 reward);
constructor() public {
owner = msg.sender;
totalSupply_ = INITIAL_SUPPLY;
balances[roto] = INITIAL_SUPPLY;
emit Transfer(0x0, roto, INITIAL_SUPPLY);
}
/**
* @dev A function that can only be called by RotoHive, transfers Roto Tokens out of the contract.
@param _to address, the address that the ROTO will be transferred to
@param _value ROTO, amount to transfer
@return - whether the Roto was transferred succesfully
*/
function transferFromContract(address _to, uint256 _value) public onlyOwner returns(bool) {
require(_to!=address(0));
require(_value<=balances[roto]);
require(owner_transfer > 0);
owner_transfer = owner_transfer.sub(_value);
balances[roto] = balances[roto].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(roto, _to, _value);
return true;
}
/**
@dev updates the helper contract(which will manage the tournament) with the new version
@param _contract address, the address of the manager contract
@return - whether the contract was successfully set
*/
function setManagerContract(address _contract) external onlyOwner returns(bool) {
//checks that the address sent isn't the 0 address, the owner or the token contract
require(_contract!=address(0)&&_contract!=roto);
// requires that the address sent be a contract
uint size;
assembly { size := extcodesize(_contract) }
require(size > 0);
manager = _contract;
emit ManagerChanged(_contract);
return true;
}
/**
@dev - called by the manager contract to add back to the user their roto in the event that their submission was successful
@param _user address, the address of the user who submitted the rankings
@param _tournamentID identifier
@return boolean value, whether the roto were successfully released
*/
function releaseRoto(address _user, bytes32 _tournamentID) external onlyManager returns(bool) {
require(_user!=address(0));
uint256 value = stakes[_user][_tournamentID];
require(value > 0);
stakes[_user][_tournamentID] = 0;
balances[_user] = balances[_user].add(value);
emit RotoReleased(_user, value);
return true;
}
/**
@dev - function called by manager contract to process the accounting aspects of the destroyRoto function
@param _user address, the address of the user who's stake will be destroyed
@param _tournamentID identifier
@return - a boolean value that reflects whether the roto were successfully destroyed
*/
function destroyRoto(address _user, bytes32 _tournamentID) external onlyManager returns(bool) {
require(_user!=address(0));
uint256 value = stakes[_user][_tournamentID];
require(value > 0);
stakes[_user][_tournamentID] = 0;
balances[roto] = balances[roto].add(value);
emit RotoDestroyed(_user, value);
return true;
}
/**
@dev - called by the manager contract, runs the accounting portions of the staking process
@param _user address, the address of the user staking ROTO
@param _tournamentID identifier
@param _value ROTO, the amount the user is staking
@return - whether the staking process went successfully
*/
function stakeRoto(address _user, bytes32 _tournamentID, uint256 _value) external onlyManager returns(bool) {
require(_user!=address(0));
require(_value<=balances[_user]);
require(stakes[_user][_tournamentID] == 0);
balances[_user] = balances[_user].sub(_value);
stakes[_user][_tournamentID] = _value;
emit RotoStaked(_user, _value);
return true;
}
/**
@dev - called by the manager contract, used to reward non-staked submissions by users
@param _user address, the address that will receive the rewarded ROTO
@param _value ROTO, the amount of ROTO that they'll be rewarded
*/
function rewardRoto(address _user, uint256 _value) external onlyManager returns(bool successful) {
require(_user!=address(0));
require(_value<=balances[roto]);
balances[_user] = balances[_user].add(_value);
balances[roto] = balances[roto].sub(_value);
emit Transfer(roto, _user, _value);
return true;
}
/**
@dev - to be called by the manager contract to check if a given user has enough roto to
stake the given amount
@param _user address, the address of the user who's attempting to stake ROTO
@param _value ROTO, the amount they are attempting to stake
@return - whether the user has enough balance to stake the received amount
*/
function canStake(address _user, uint256 _value) public view onlyManager returns(bool) {
require(_user!=address(0));
require(_value<=balances[_user]);
return true;
}
/**
@dev Getter function for manager
*/
function getManager() public view returns (address _manager) {
return manager;
}
/**
@dev - sets the owner address to a new one
@param _newOwner address
@return - true if the address was changed successful
*/
function changeOwner(address _newOwner) public onlyOwner returns(bool) {
owner = _newOwner;
}
}