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@ShardixDB ShardixDB/Test.rdn
Last active Apr 14, 2018

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pragma solidity ^0.4.18;
/**
* @title ERC20Basic
* @dev Simpler version of ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/179
*/
contract ERC20Basic {
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 ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20 is ERC20Basic {
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);
}
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a * b;
assert(a == 0 || c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal pure 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 pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
contract Hive is ERC20 {
using SafeMath for uint;
string public constant name = "UHIVE";
string public constant symbol = "HVE";
uint256 public constant decimals = 18;
uint256 _totalSupply = 80000000000 * (10**decimals);
mapping (address => bool) public frozenAccount;
event FrozenFunds(address target, bool frozen);
// Balances for each account
mapping(address => uint256) balances;
// Owner of account approves the transfer of an amount to another account
mapping(address => mapping (address => uint256)) allowed;
// Owner of this contract
address public owner;
// Functions with this modifier can only be executed by the owner
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
function changeOwner(address _newOwner) onlyOwner public {
require(_newOwner != address(0));
owner = _newOwner;
}
function freezeAccount(address target, bool freeze) onlyOwner public {
frozenAccount[target] = freeze;
FrozenFunds(target, freeze);
}
function isFrozenAccount(address _addr) public constant returns (bool) {
return frozenAccount[_addr];
}
function destroyCoins(address addressToDestroy, uint256 amount) onlyOwner public {
require(addressToDestroy != address(0));
require(amount > 0);
require(amount <= balances[addressToDestroy]);
balances[addressToDestroy] -= amount;
_totalSupply -= amount;
}
// Constructor
function Hive() public {
owner = msg.sender;
balances[owner] = _totalSupply;
}
function totalSupply() public constant returns (uint256 supply) {
supply = _totalSupply;
}
// What is the balance of a particular account?
function balanceOf(address _owner) public constant returns (uint256 balance) {
return balances[_owner];
}
// Transfer the balance from owner's account to another account
function transfer(address _to, uint256 _value) public returns (bool success) {
if (_to != address(0) && isFrozenAccount(msg.sender) == false && balances[msg.sender] >= _value && _value > 0 && balances[_to] + _value > balances[_to]) {
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
Transfer(msg.sender, _to, _value);
return true;
} else {
return false;
}
}
// Send _value amount of tokens from address _from to address _to
// The transferFrom method is used for a withdraw workflow, allowing contracts to send
// tokens on your behalf, for example to "deposit" to a contract address and/or to charge
// fees in sub-currencies; the command should fail unless the _from account has
// deliberately authorized the sender of the message via some mechanism; we propose
// these standardized APIs for approval:
function transferFrom(address _from,address _to, uint256 _value) public returns (bool success) {
if (_to != address(0) && isFrozenAccount(_from) == false && balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0 && balances[_to] + _value > balances[_to]) {
balances[_from] = balances[_from].sub(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
Transfer(_from, _to, _value);
return true;
} else {
return false;
}
}
// Allow _spender to withdraw from your account, multiple times, up to the _value amount.
// If this function is called again it overwrites the current allowance with _value.
function approve(address _spender, uint256 _value) public returns (bool success) {
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
return true;
}
function allowance(address _owner, address _spender) public constant returns (uint256 remaining) {
return allowed[_owner][_spender];
}
}
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