Transaction Hash:
Block:
6377859 at Sep-22-2018 09:40:44 AM +UTC
Transaction Fee:
0.00018326 ETH
$0.47
Gas Used:
45,815 Gas / 4 Gwei
Emitted Events:
19 |
DistributedCreditChain.Approval( owner=[Sender] 0x9d7a25bcfcd7fd24fe8e69c2f6f103ab7a3e53d4, spender=0x8d12A197...2A5CC6819, value=1420000000000000000000 )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x9d7A25bc...B7a3E53d4 |
0.052923729938114246 Eth
Nonce: 32
|
0.052740469938114246 Eth
Nonce: 33
| 0.00018326 | ||
0xcC16E3c0...786dfE610
Miner
| 25,207.382796529315579158 Eth | 25,207.382979789315579158 Eth | 0.00018326 | ||
0xFFa93Aac...52FDFB961 |
Execution Trace
DistributedCreditChain.approve( _spender=0x8d12A197cB00D4747a1fe03395095ce2A5CC6819, _value=1420000000000000000000 ) => ( True )
approve[ERC20 (ln:156)]
pragma solidity ^0.4.18; /** * @title Ownable * @dev The Ownable contract has an owner address, and provides basic authorization control * functions, this simplifies the implementation of "user permissions". */ contract Ownable { address public owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev The Ownable constructor sets the original `owner` of the contract to the sender * account. */ function Ownable() public { 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) public onlyOwner { require(newOwner != address(0)); OwnershipTransferred(owner, newOwner); owner = newOwner; } } /** * @title ERC20Basic * @dev Simpler version of ERC20 interface * @dev see https://github.com/ethereum/EIPs/issues/179 */ contract ERC20Basic { uint256 public totalSupply; 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); } contract BasicToken is ERC20Basic, Ownable { using SafeMath for uint256; mapping(address => uint256) balances; bool public transfersEnabledFlag; /** * @dev Throws if transfersEnabledFlag is false and not owner. */ modifier transfersEnabled() { require(transfersEnabledFlag); _; } function enableTransfers() public onlyOwner { transfersEnabledFlag = true; } /** * @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) transfersEnabled public returns (bool) { require(_to != address(0)); require(_value <= balances[msg.sender]); // SafeMath.sub will throw if there is not enough balance. balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); Transfer(msg.sender, _to, _value); return true; } function batchTransfer(address[] _addresses, uint256[] _value) public returns (bool) { for (uint256 i = 0; i < _addresses.length; i++) { require(transfer(_addresses[i], _value[i])); } 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]; } } /** * @title SafeMath * @dev Math operations with safety checks that throw on error */ library SafeMath { function mul(uint256 a, uint256 b) internal pure returns (uint256) { if (a == 0) { return 0; } uint256 c = a * b; assert(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; } } /** * @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); } /** * @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, BasicToken { 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) transfersEnabled 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); 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) transfersEnabled public returns (bool) { 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 specifying the amount of tokens still available for the spender. */ function allowance(address _owner, address _spender) public view returns (uint256) { return allowed[_owner][_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 */ function increaseApproval(address _spender, uint _addedValue) transfersEnabled public returns (bool) { allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue); Approval(msg.sender, _spender, allowed[msg.sender][_spender]); return true; } function decreaseApproval(address _spender, uint _subtractedValue) transfersEnabled 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); } Approval(msg.sender, _spender, allowed[msg.sender][_spender]); return true; } } /** * @title Mintable token * @dev Simple ERC20 Token example, with mintable token creation * @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol */ contract MintableToken is StandardToken { event Mint(address indexed to, uint256 amount); event MintFinished(); bool public mintingFinished = false; mapping(address => bool) public minters; modifier canMint() { require(!mintingFinished); _; } modifier onlyMinters() { require(minters[msg.sender] || msg.sender == owner); _; } function addMinter(address _addr) public onlyOwner { require(_addr != address(0)); minters[_addr] = true; } function deleteMinter(address _addr) public onlyOwner { require(_addr != address(0)); delete minters[_addr]; } /** * @dev Function to mint tokens * @param _to The address that will receive the minted tokens. * @param _amount The amount of tokens to mint. * @return A boolean that indicates if the operation was successful. */ function mint(address _to, uint256 _amount) onlyMinters canMint public returns (bool) { require(_to != address(0)); totalSupply = totalSupply.add(_amount); balances[_to] = balances[_to].add(_amount); Mint(_to, _amount); Transfer(address(0), _to, _amount); return true; } /** * @dev Function to stop minting new tokens. * @return True if the operation was successful. */ function finishMinting() onlyOwner canMint public returns (bool) { mintingFinished = true; MintFinished(); return true; } } /** * @title Capped token * @dev Mintable token with a token cap. */ contract CappedToken is MintableToken { uint256 public cap; function CappedToken(uint256 _cap) public { require(_cap > 0); cap = _cap; } /** * @dev Function to mint tokens * @param _to The address that will receive the minted tokens. * @param _amount The amount of tokens to mint. * @return A boolean that indicates if the operation was successful. */ function mint(address _to, uint256 _amount) onlyMinters canMint public returns (bool) { require(totalSupply.add(_amount) <= cap); return super.mint(_to, _amount); } } contract ParameterizedToken is CappedToken { //1.3 update add minter/delete minter address validation string public version = "1.3"; string public name; string public symbol; uint256 public decimals; function ParameterizedToken(string _name, string _symbol, uint256 _decimals, uint256 _capIntPart) public CappedToken(_capIntPart * 10 ** _decimals) { name = _name; symbol = _symbol; decimals = _decimals; } } contract DistributedCreditChain is ParameterizedToken { function DistributedCreditChain() public ParameterizedToken("Distributed Credit Chain", "DCC", 18, 10000000000) { } }