Skip to content

Instantly share code, notes, and snippets.

@forthxu
Created Jun 20, 2018
Embed
What would you like to do?
Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.4.24+commit.e67f0147.js&optimize=false&gist=
pragma solidity ^0.4.23;
/**
* @title ERC20 interface
*/
contract ERC20 {
function totalSupply()
public view returns (uint256);
function balanceOf(address who)
public view returns (uint256);
function transfer(address to, uint256 value)
public returns (bool);
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
);
event Transfer(
address indexed from,
address indexed to,
uint256 value);
}
/**
* @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.
*/
constructor() 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));
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
}
}
/**
* @title ERC827 interface, an extension of ERC20 token standard
*
* @dev Interface of a ERC827 token, following the ERC20 standard with extra
* @dev methods to transfer value and data and execute calls in transfers and
* @dev approvals.
*/
contract ERC827 is ERC20 {
function approveAndCall(
address _spender,
uint256 _value,
bytes _data
)
public
payable
returns (bool);
function transferAndCall(
address _to,
uint256 _value,
bytes _data
)
public
payable
returns (bool);
function transferFromAndCall(
address _from,
address _to,
uint256 _value,
bytes _data
)
public
payable
returns (bool);
}
/**
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
/**
* @dev Multiplies two numbers, throws on overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
if (a == 0) {
return 0;
}
c = a * b;
assert(c / a == b);
return c;
}
/**
* @dev Integer division of two numbers, truncating the quotient.
*/
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 a / b;
}
/**
* @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 Standard ERC20 token
*
*/
contract ERC20Token is ERC20{
using SafeMath for uint256;
mapping (address => mapping (address => uint256)) internal allowed;
mapping(address => uint256) balances;
uint256 totalSupply_;
/**
* @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) {
return balances[_owner];
}
/**
* @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.
*/
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;
}
}
/**
* @title ERC827, an extension of ERC20 token standard
*
* @dev Implementation the ERC827, following the ERC20 standard with extra
* @dev methods to transfer value and data and execute calls in transfers and
* @dev approvals.
*
* @dev Uses OpenZeppelin StandardToken.
*/
contract ERC827Token is ERC827, ERC20Token {
/**
* @dev Addition to ERC20 token methods. It allows to
* @dev approve the transfer of value and execute a call with the sent data.
*
* @dev Beware that changing an allowance with this method brings the risk that
* @dev someone may use both the old and the new allowance by unfortunate
* @dev transaction ordering. One possible solution to mitigate this race condition
* @dev is to first reduce the spender's allowance to 0 and set the desired value
* @dev afterwards:
* @dev https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* @param _spender The address that will spend the funds.
* @param _value The amount of tokens to be spent.
* @param _data ABI-encoded contract call to call `_to` address.
*
* @return true if the call function was executed successfully
*/
function approveAndCall(
address _spender,
uint256 _value,
bytes _data
)
public
payable
returns (bool)
{
require(_spender != address(this));
super.approve(_spender, _value);
// solium-disable-next-line security/no-call-value
require(_spender.call.value(msg.value)(_data));
return true;
}
/**
* @dev Addition to ERC20 token methods. Transfer tokens to a specified
* @dev address and execute a call with the sent data on the same transaction
*
* @param _to address The address which you want to transfer to
* @param _value uint256 the amout of tokens to be transfered
* @param _data ABI-encoded contract call to call `_to` address.
*
* @return true if the call function was executed successfully
*/
function transferAndCall(
address _to,
uint256 _value,
bytes _data
)
public
payable
returns (bool)
{
require(_to != address(this));
super.transfer(_to, _value);
require(_to.call.value(msg.value)(_data));
return true;
}
/**
* @dev Addition to ERC20 token methods. Transfer tokens from one address to
* @dev another and make a contract call on the same transaction
*
* @param _from The address which you want to send tokens from
* @param _to The address which you want to transfer to
* @param _value The amout of tokens to be transferred
* @param _data ABI-encoded contract call to call `_to` address.
*
* @return true if the call function was executed successfully
*/
function transferFromAndCall(
address _from,
address _to,
uint256 _value,
bytes _data
)
public payable returns (bool)
{
require(_to != address(this));
super.transferFrom(_from, _to, _value);
require(_to.call.value(msg.value)(_data));
return true;
}
/**
* @dev Addition to StandardToken methods. Increase the amount of tokens that
* @dev an owner allowed to a spender and execute a call with the sent data.
*
* @dev approve should be called when allowed[_spender] == 0. To increment
* @dev allowed value is better to use this function to avoid 2 calls (and wait until
* @dev the first transaction is mined)
* @dev From MonolithDAO Token.sol
*
* @param _spender The address which will spend the funds.
* @param _addedValue The amount of tokens to increase the allowance by.
* @param _data ABI-encoded contract call to call `_spender` address.
*/
function increaseApprovalAndCall(
address _spender,
uint _addedValue,
bytes _data
)
public
payable
returns (bool)
{
require(_spender != address(this));
super.increaseApproval(_spender, _addedValue);
require(_spender.call.value(msg.value)(_data));
return true;
}
/**
* @dev Addition to StandardToken methods. Decrease the amount of tokens that
* @dev an owner allowed to a spender and execute a call with the sent data.
*
* @dev approve should be called when allowed[_spender] == 0. To decrement
* @dev allowed value is better to use this function to avoid 2 calls (and wait until
* @dev the first transaction is mined)
* @dev From MonolithDAO Token.sol
*
* @param _spender The address which will spend the funds.
* @param _subtractedValue The amount of tokens to decrease the allowance by.
* @param _data ABI-encoded contract call to call `_spender` address.
*/
function decreaseApprovalAndCall(
address _spender,
uint _subtractedValue,
bytes _data
)
public
payable
returns (bool)
{
require(_spender != address(this));
super.decreaseApproval(_spender, _subtractedValue);
require(_spender.call.value(msg.value)(_data));
return true;
}
}
/**
* @title Burnable and Pause Token
* @dev StandardToken modified with pausable transfers.
**/
contract PauseBurnableERC827Token is ERC827Token, Ownable{
using SafeMath for uint256;
event Pause();
event Unpause();
event PauseOperatorTransferred(address indexed previousOperator,address indexed newOperator);
event Burn(address indexed burner, uint256 value);
bool public paused = false;
address public pauseOperator;
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyPauseOperator() {
require(msg.sender == pauseOperator || msg.sender == owner);
_;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() {
require(!paused);
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() {
require(paused);
_;
}
/**
* @dev The constructor sets the original `owner` of the contract to the sender
* account.
*/
constructor() public {
pauseOperator = msg.sender;
}
/**
* @dev called by the operator to set the new operator to pause the token
*/
function transferPauseOperator(address newPauseOperator) onlyPauseOperator public {
require(newPauseOperator != address(0));
emit PauseOperatorTransferred(pauseOperator, newPauseOperator);
pauseOperator = newPauseOperator;
}
/**
* @dev called by the owner to pause, triggers stopped state
*/
function pause() onlyPauseOperator whenNotPaused public {
paused = true;
emit Pause();
}
/**
* @dev called by the owner to unpause, returns to normal state
*/
function unpause() onlyPauseOperator whenPaused public {
paused = false;
emit Unpause();
}
function transfer(address _to,uint256 _value)
public
whenNotPaused
returns (bool)
{
return super.transfer(_to, _value);
}
function transferFrom(address _from,address _to,uint256 _value)
public
whenNotPaused
returns (bool)
{
return super.transferFrom(_from, _to, _value);
}
function approve(address _spender,uint256 _value)
public
whenNotPaused
returns (bool)
{
return super.approve(_spender, _value);
}
function increaseApproval(address _spender,uint _addedValue)
public
whenNotPaused
returns (bool success)
{
return super.increaseApproval(_spender, _addedValue);
}
function decreaseApproval(address _spender,uint _subtractedValue)
public
whenNotPaused
returns (bool success)
{
return super.decreaseApproval(_spender, _subtractedValue);
}
/**
* @dev Burns a specific amount of tokens.
* @param _value The amount of token to be burned.
*/
function burn(uint256 _value)
public whenNotPaused
{
_burn(msg.sender, _value);
}
function _burn(address _who, uint256 _value) internal{
require(_value <= balances[_who]);
// no need to require value <= totalSupply, since that would imply the
// sender's balance is greater than the totalSupply, which *should* be an assertion failure
balances[_who] = balances[_who].sub(_value); // Subtract from the sender
totalSupply_ = totalSupply_.sub(_value);
emit Burn(_who, _value);
emit Transfer(_who, address(0), _value);
}
/**
* @dev Burns a specific amount of tokens from the target address and decrements allowance
* @param _from address The address which you want to send tokens from
* @param _value uint256 The amount of token to be burned
*/
function burnFrom(address _from, uint256 _value)
public whenNotPaused
{
require(_value <= allowed[_from][msg.sender]);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
_burn(_from, _value);
}
}
/**
* @title the Blockchain Quotations Token for BQI.COM
*
* @dev Uses OpenZeppelin Lib.
*/
contract BQT is PauseBurnableERC827Token {
string public constant name = "BQT";
string public constant symbol = "BQT";
uint8 public constant decimals = 18;
uint256 public constant INITIAL_SUPPLY = 1000000000 * (10 ** uint256(decimals));
/**
* @dev Constructor that gives msg.sender all of existing tokens.
*/
constructor() public {
totalSupply_ = INITIAL_SUPPLY;
balances[msg.sender] = INITIAL_SUPPLY;
emit Transfer(0x0, msg.sender, INITIAL_SUPPLY);
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment