-
-
Save dworznik/b510739401066fb61050c49bc97c8306 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
pragma solidity ^0.4.13; | |
library SafeMath { | |
function mul(uint256 a, uint256 b) internal constant returns (uint256) { | |
uint256 c = a * b; | |
assert(a == 0 || c / a == b); | |
return c; | |
} | |
function div(uint256 a, uint256 b) internal constant returns (uint256) { | |
// assert(b > 0); // Solidity automatically throws when dividing by 0 | |
uint256 c = a / b; | |
// assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
return c; | |
} | |
function sub(uint256 a, uint256 b) internal constant returns (uint256) { | |
assert(b <= a); | |
return a - b; | |
} | |
function add(uint256 a, uint256 b) internal constant returns (uint256) { | |
uint256 c = a + b; | |
assert(c >= a); | |
return c; | |
} | |
} | |
contract Ownable { | |
address public owner; | |
/** | |
* @dev The Ownable constructor sets the original `owner` of the contract to the sender | |
* account. | |
*/ | |
function Ownable() { | |
owner = msg.sender; | |
} | |
/** | |
* @dev Throws if called by any account other than the owner. | |
*/ | |
modifier onlyOwner() { | |
require(msg.sender == owner); | |
_; | |
} | |
/** | |
* @dev Allows the current owner to transfer control of the contract to a newOwner. | |
* @param newOwner The address to transfer ownership to. | |
*/ | |
function transferOwnership(address newOwner) onlyOwner { | |
if (newOwner != address(0)) { | |
owner = newOwner; | |
} | |
} | |
} | |
contract ERC20Basic { | |
uint256 public totalSupply; | |
function balanceOf(address who) constant returns (uint256); | |
function transfer(address to, uint256 value) returns (bool); | |
event Transfer(address indexed from, address indexed to, uint256 value); | |
} | |
contract BasicToken is ERC20Basic { | |
using SafeMath for uint256; | |
mapping(address => uint256) balances; | |
/** | |
* @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) returns (bool) { | |
balances[msg.sender] = balances[msg.sender].sub(_value); | |
balances[_to] = balances[_to].add(_value); | |
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) constant returns (uint256 balance) { | |
return balances[_owner]; | |
} | |
} | |
contract ERC20 is ERC20Basic { | |
function allowance(address owner, address spender) constant returns (uint256); | |
function transferFrom(address from, address to, uint256 value) returns (bool); | |
function approve(address spender, uint256 value) returns (bool); | |
event Approval(address indexed owner, address indexed spender, uint256 value); | |
} | |
contract StandardToken is ERC20, BasicToken { | |
mapping (address => mapping (address => uint256)) 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 amout of tokens to be transfered | |
*/ | |
function transferFrom(address _from, address _to, uint256 _value) returns (bool) { | |
var _allowance = allowed[_from][msg.sender]; | |
// Check is not needed because sub(_allowance, _value) will already throw if this condition is not met | |
// require (_value <= _allowance); | |
balances[_to] = balances[_to].add(_value); | |
balances[_from] = balances[_from].sub(_value); | |
allowed[_from][msg.sender] = _allowance.sub(_value); | |
Transfer(_from, _to, _value); | |
return true; | |
} | |
/** | |
* @dev Aprove the passed address to spend the specified amount of tokens on behalf 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, uint256 _value) returns (bool) { | |
// 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 | |
require((_value == 0) || (allowed[msg.sender][_spender] == 0)); | |
allowed[msg.sender][_spender] = _value; | |
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 specifing the amount of tokens still avaible for the spender. | |
*/ | |
function allowance(address _owner, address _spender) constant returns (uint256 remaining) { | |
return allowed[_owner][_spender]; | |
} | |
} | |
contract TokenizedAsset is StandardToken, Ownable { | |
//--- Definitions | |
using SafeMath for uint256; | |
//--- Storage | |
string public name; | |
string public symbol; | |
uint256 public decimals; | |
uint256 public unitAmount; | |
uint256 public tokenPrice; | |
//--- Construction | |
/** | |
* @param _tokenPrice Price of 1 token denominated in Wei (ignoring the token decimals) | |
*/ | |
function TokenizedAsset( | |
string _name, | |
string _symbol, | |
uint256 _decimals, | |
uint256 _totalSupply, | |
uint256 _tokenPrice | |
) { | |
require(bytes(_name).length > 0); | |
require(bytes(_symbol).length > 0); | |
require(_decimals > 0 && _decimals <= 32); | |
require(_totalSupply > 0); | |
require(_tokenPrice > 0); | |
name = _name; | |
symbol = _symbol; | |
decimals = _decimals; | |
unitAmount = 10 ** decimals; | |
totalSupply = _totalSupply; | |
tokenPrice = _tokenPrice; | |
balances[this] = _totalSupply; | |
} | |
//--- Accessors | |
/** | |
* @dev Updates the token value | |
* @param _tokenPrice Price of 1 token denominated in Wei (ignoring the token decimals) | |
*/ | |
function setTokenPrice(uint256 _tokenPrice) public onlyOwner { | |
require(_tokenPrice > 0); | |
tokenPrice = _tokenPrice; | |
} | |
//--- Events | |
event TokenBought(address indexed account, uint256 tokenAmount, uint256 value); | |
//--- Public mutable functions | |
function buy(uint256 tokenAmount) public payable { | |
uint256 expectedValue = tokenAmount.mul(tokenPrice).div(unitAmount); | |
require(msg.value == expectedValue); | |
balances[msg.sender] = balances[msg.sender].add(tokenAmount); | |
balances[this] = balances[this].sub(tokenAmount); | |
TokenBought(msg.sender, tokenAmount, msg.value); | |
} | |
function withdraw(uint256 value) public onlyOwner { | |
msg.sender.transfer(value); | |
} | |
function () { | |
// prevent accidental sending of Ether | |
revert(); | |
} | |
} | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment