Contract Source Code:
File 1 of 1 : CDTToken
pragma solidity ^0.4.8;
/**
* Math operations with safety checks
*/
library SafeMath {
function mul(uint a, uint b) internal returns (uint) {
uint c = a * b;
assert(a == 0 || c / a == b);
return c;
}
function div(uint a, uint b) internal returns (uint) {
// assert(b > 0); // Solidity automatically throws when dividing by 0
uint c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
function sub(uint a, uint b) internal returns (uint) {
assert(b <= a);
return a - b;
}
function add(uint a, uint b) internal returns (uint) {
uint c = a + b;
assert(c >= a);
return c;
}
function max64(uint64 a, uint64 b) internal constant returns (uint64) {
return a >= b ? a : b;
}
function min64(uint64 a, uint64 b) internal constant returns (uint64) {
return a < b ? a : b;
}
function max256(uint256 a, uint256 b) internal constant returns (uint256) {
return a >= b ? a : b;
}
function min256(uint256 a, uint256 b) internal constant returns (uint256) {
return a < b ? a : b;
}
function assert(bool assertion) internal {
if (!assertion) {
throw;
}
}
}
/**
* @title ERC20Basic
* @dev Simpler version of ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20Basic {
uint public totalSupply;
function balanceOf(address who) constant returns (uint);
function transfer(address to, uint value);
event Transfer(address indexed from, address indexed to, uint value);
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20 is ERC20Basic {
function allowance(address owner, address spender) constant returns (uint);
function transferFrom(address from, address to, uint value);
function approve(address spender, uint value);
event Approval(address indexed owner, address indexed spender, uint value);
}
/**
* @title LimitedTransferToken
* @dev LimitedTransferToken defines the generic interface and the implementation to limit token
* transferability for different events. It is intended to be used as a base class for other token
* contracts.
* LimitedTransferToken has been designed to allow for different limiting factors,
* this can be achieved by recursively calling super.transferableTokens() until the base class is
* hit. For example:
* function transferableTokens(address holder, uint64 time) constant public returns (uint256) {
* return min256(unlockedTokens, super.transferableTokens(holder, time));
* }
* A working example is VestedToken.sol:
* https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/token/VestedToken.sol
*/
contract LimitedTransferToken is ERC20 {
/**
* @dev Checks whether it can transfer or otherwise throws.
*/
modifier canTransfer(address _sender, uint _value) {
if (_value > transferableTokens(_sender, uint64(now))) throw;
_;
}
/**
* @dev Checks modifier and allows transfer if tokens are not locked.
* @param _to The address that will recieve the tokens.
* @param _value The amount of tokens to be transferred.
*/
function transfer(address _to, uint _value) canTransfer(msg.sender, _value) {
return super.transfer(_to, _value);
}
/**
* @dev Checks modifier and allows transfer if tokens are not locked.
* @param _from The address that will send the tokens.
* @param _to The address that will recieve the tokens.
* @param _value The amount of tokens to be transferred.
*/
function transferFrom(address _from, address _to, uint _value) canTransfer(_from, _value) {
return super.transferFrom(_from, _to, _value);
}
/**
* @dev Default transferable tokens function returns all tokens for a holder (no limit).
* @dev Overwriting transferableTokens(address holder, uint64 time) is the way to provide the
* specific logic for limiting token transferability for a holder over time.
*/
function transferableTokens(address holder, uint64 time) constant public returns (uint256) {
return balanceOf(holder);
}
}
/**
* @title Basic token
* @dev Basic version of StandardToken, with no allowances.
*/
contract BasicToken is ERC20Basic {
using SafeMath for uint;
mapping(address => uint) balances;
/**
* @dev Fix for the ERC20 short address attack.
*/
modifier onlyPayloadSize(uint size) {
if(msg.data.length < size + 4) {
throw;
}
_;
}
/**
* @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, uint _value) onlyPayloadSize(2 * 32) {
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
Transfer(msg.sender, _to, _value);
}
/**
* @dev Gets the balance of the specified address.
* @param _owner The address to query the the balance of.
* @return An uint representing the amount owned by the passed address.
*/
function balanceOf(address _owner) constant returns (uint balance) {
return balances[_owner];
}
}
/**
* @title Standard ERC20 token
*
* @dev Implemantation of the basic standart 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 BasicToken, ERC20 {
mapping (address => mapping (address => uint)) 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 uint the amout of tokens to be transfered
*/
function transferFrom(address _from, address _to, uint _value) onlyPayloadSize(3 * 32) {
var _allowance = allowed[_from][msg.sender];
// Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
// if (_value > _allowance) throw;
balances[_to] = balances[_to].add(_value);
balances[_from] = balances[_from].sub(_value);
allowed[_from][msg.sender] = _allowance.sub(_value);
Transfer(_from, _to, _value);
}
/**
* @dev Aprove the passed address to spend the specified amount of tokens on beahlf of msg.sender.
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint _value) {
// To change the approve amount you first have to reduce the addresses`
// allowance to zero by calling `approve(_spender, 0)` if it is not
// already 0 to mitigate the race condition described here:
// https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
if ((_value != 0) && (allowed[msg.sender][_spender] != 0)) throw;
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
}
/**
* @dev Function to check the amount of tokens than 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 uint specifing the amount of tokens still avaible for the spender.
*/
function allowance(address _owner, address _spender) constant returns (uint remaining) {
return allowed[_owner][_spender];
}
}
/**
* @title Vested token
* @dev Tokens that can be vested for a group of addresses.
*/
contract VestedToken is StandardToken, LimitedTransferToken {
uint256 MAX_GRANTS_PER_ADDRESS = 20;
struct TokenGrant {
address granter; // 20 bytes
uint256 value; // 32 bytes
uint64 cliff;
uint64 vesting;
uint64 start; // 3 * 8 = 24 bytes
bool revokable;
bool burnsOnRevoke; // 2 * 1 = 2 bits? or 2 bytes?
} // total 78 bytes = 3 sstore per operation (32 per sstore)
mapping (address => TokenGrant[]) public grants;
event NewTokenGrant(address indexed from, address indexed to, uint256 value, uint256 grantId);
/**
* @dev Grant tokens to a specified address
* @param _to address The address which the tokens will be granted to.
* @param _value uint256 The amount of tokens to be granted.
* @param _start uint64 Time of the beginning of the grant.
* @param _cliff uint64 Time of the cliff period.
* @param _vesting uint64 The vesting period.
*/
function grantVestedTokens(
address _to,
uint256 _value,
uint64 _start,
uint64 _cliff,
uint64 _vesting,
bool _revokable,
bool _burnsOnRevoke
) public {
// Check for date inconsistencies that may cause unexpected behavior
if (_cliff < _start || _vesting < _cliff) {
throw;
}
if (tokenGrantsCount(_to) > MAX_GRANTS_PER_ADDRESS) throw; // To prevent a user being spammed and have his balance locked (out of gas attack when calculating vesting).
uint count = grants[_to].push(
TokenGrant(
_revokable ? msg.sender : 0, // avoid storing an extra 20 bytes when it is non-revokable
_value,
_cliff,
_vesting,
_start,
_revokable,
_burnsOnRevoke
)
);
transfer(_to, _value);
NewTokenGrant(msg.sender, _to, _value, count - 1);
}
/**
* @dev Revoke the grant of tokens of a specifed address.
* @param _holder The address which will have its tokens revoked.
* @param _grantId The id of the token grant.
*/
function revokeTokenGrant(address _holder, uint _grantId) public {
TokenGrant grant = grants[_holder][_grantId];
if (!grant.revokable) { // Check if grant was revokable
throw;
}
if (grant.granter != msg.sender) { // Only granter can revoke it
throw;
}
address receiver = grant.burnsOnRevoke ? 0xdead : msg.sender;
uint256 nonVested = nonVestedTokens(grant, uint64(now));
// remove grant from array
delete grants[_holder][_grantId];
grants[_holder][_grantId] = grants[_holder][grants[_holder].length.sub(1)];
grants[_holder].length -= 1;
balances[receiver] = balances[receiver].add(nonVested);
balances[_holder] = balances[_holder].sub(nonVested);
Transfer(_holder, receiver, nonVested);
}
/**
* @dev Calculate the total amount of transferable tokens of a holder at a given time
* @param holder address The address of the holder
* @param time uint64 The specific time.
* @return An uint representing a holder's total amount of transferable tokens.
*/
function transferableTokens(address holder, uint64 time) constant public returns (uint256) {
uint256 grantIndex = tokenGrantsCount(holder);
if (grantIndex == 0) return balanceOf(holder); // shortcut for holder without grants
// Iterate through all the grants the holder has, and add all non-vested tokens
uint256 nonVested = 0;
for (uint256 i = 0; i < grantIndex; i++) {
nonVested = SafeMath.add(nonVested, nonVestedTokens(grants[holder][i], time));
}
// Balance - totalNonVested is the amount of tokens a holder can transfer at any given time
uint256 vestedTransferable = SafeMath.sub(balanceOf(holder), nonVested);
// Return the minimum of how many vested can transfer and other value
// in case there are other limiting transferability factors (default is balanceOf)
return SafeMath.min256(vestedTransferable, super.transferableTokens(holder, time));
}
/**
* @dev Check the amount of grants that an address has.
* @param _holder The holder of the grants.
* @return A uint representing the total amount of grants.
*/
function tokenGrantsCount(address _holder) constant returns (uint index) {
return grants[_holder].length;
}
/**
* @dev Calculate amount of vested tokens at a specifc time.
* @param tokens uint256 The amount of tokens grantted.
* @param time uint64 The time to be checked
* @param start uint64 A time representing the begining of the grant
* @param cliff uint64 The cliff period.
* @param vesting uint64 The vesting period.
* @return An uint representing the amount of vested tokensof a specif grant.
* transferableTokens
* | _/-------- vestedTokens rect
* | _/
* | _/
* | _/
* | _/
* | /
* | .|
* | . |
* | . |
* | . |
* | . |
* | . |
* +===+===========+---------+----------> time
* Start Clift Vesting
*/
function calculateVestedTokens(
uint256 tokens,
uint256 time,
uint256 start,
uint256 cliff,
uint256 vesting) constant returns (uint256)
{
// Shortcuts for before cliff and after vesting cases.
if (time < cliff) return 0;
if (time >= vesting) return tokens;
// Interpolate all vested tokens.
// As before cliff the shortcut returns 0, we can use just calculate a value
// in the vesting rect (as shown in above's figure)
// vestedTokens = tokens * (time - start) / (vesting - start)
uint256 vestedTokens = SafeMath.div(
SafeMath.mul(
tokens,
SafeMath.sub(time, start)
),
SafeMath.sub(vesting, start)
);
return vestedTokens;
}
/**
* @dev Get all information about a specifc grant.
* @param _holder The address which will have its tokens revoked.
* @param _grantId The id of the token grant.
* @return Returns all the values that represent a TokenGrant(address, value, start, cliff,
* revokability, burnsOnRevoke, and vesting) plus the vested value at the current time.
*/
function tokenGrant(address _holder, uint _grantId) constant returns (address granter, uint256 value, uint256 vested, uint64 start, uint64 cliff, uint64 vesting, bool revokable, bool burnsOnRevoke) {
TokenGrant grant = grants[_holder][_grantId];
granter = grant.granter;
value = grant.value;
start = grant.start;
cliff = grant.cliff;
vesting = grant.vesting;
revokable = grant.revokable;
burnsOnRevoke = grant.burnsOnRevoke;
vested = vestedTokens(grant, uint64(now));
}
/**
* @dev Get the amount of vested tokens at a specific time.
* @param grant TokenGrant The grant to be checked.
* @param time The time to be checked
* @return An uint representing the amount of vested tokens of a specific grant at a specific time.
*/
function vestedTokens(TokenGrant grant, uint64 time) private constant returns (uint256) {
return calculateVestedTokens(
grant.value,
uint256(time),
uint256(grant.start),
uint256(grant.cliff),
uint256(grant.vesting)
);
}
/**
* @dev Calculate the amount of non vested tokens at a specific time.
* @param grant TokenGrant The grant to be checked.
* @param time uint64 The time to be checked
* @return An uint representing the amount of non vested tokens of a specifc grant on the
* passed time frame.
*/
function nonVestedTokens(TokenGrant grant, uint64 time) private constant returns (uint256) {
return grant.value.sub(vestedTokens(grant, time));
}
/**
* @dev Calculate the date when the holder can trasfer all its tokens
* @param holder address The address of the holder
* @return An uint representing the date of the last transferable tokens.
*/
function lastTokenIsTransferableDate(address holder) constant public returns (uint64 date) {
date = uint64(now);
uint256 grantIndex = grants[holder].length;
for (uint256 i = 0; i < grantIndex; i++) {
date = SafeMath.max64(grants[holder][i].vesting, date);
}
}
}
contract CDTToken is VestedToken {
using SafeMath for uint;
//FIELDS
//CONSTANTS
uint public constant decimals = 18; // 18 decimal places, the same as ETH.
string public constant name = "CoinDash Token";
string public constant symbol = "CDT";
//ASSIGNED IN INITIALIZATION
address public creator; //address of the account which may mint new tokens
//May only be called by the owner address
modifier only_owner() {
if (msg.sender != creator) throw;
_;
}
// Initialization contract assigns address of crowdfund contract and end time.
function CDTToken(uint supply) {
totalSupply = supply;
creator = msg.sender;
balances[msg.sender] = supply;
MAX_GRANTS_PER_ADDRESS = 2;
}
// Fallback function throws when called.
function() {
throw;
}
function vestedBalanceOf(address _owner) constant returns (uint balance) {
return transferableTokens(_owner, uint64(now));
}
//failsafe drain
function drain()
only_owner
{
if (!creator.send(this.balance)) throw;
}
}