Contract Source Code:
File 1 of 1 : Keep3rV1
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.12;
// From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/Math.sol
// Subject to the MIT license.
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint a, uint b) internal pure returns (uint) {
uint c = a + b;
require(c >= a, "add: +");
return c;
}
/**
* @dev Returns the addition of two unsigned integers, reverting with custom message on overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
uint c = a + b;
require(c >= a, errorMessage);
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on underflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot underflow.
*/
function sub(uint a, uint b) internal pure returns (uint) {
return sub(a, b, "sub: -");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on underflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot underflow.
*/
function sub(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
require(b <= a, errorMessage);
uint c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint a, uint b) internal pure returns (uint) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint c = a * b;
require(c / a == b, "mul: *");
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint c = a * b;
require(c / a == b, errorMessage);
return c;
}
/**
* @dev Returns the integer division of two unsigned integers.
* Reverts on division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint a, uint b) internal pure returns (uint) {
return div(a, b, "div: /");
}
/**
* @dev Returns the integer division of two unsigned integers.
* Reverts with custom message on division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint a, uint b) internal pure returns (uint) {
return mod(a, b, "mod: %");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
require(b != 0, errorMessage);
return a % b;
}
}
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor () internal {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: 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
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly { codehash := extcodehash(account) }
return (codehash != accountHash && codehash != 0x0);
}
/**
* @dev Converts an `address` into `address payable`. Note that this is
* simply a type cast: the actual underlying value is not changed.
*
* _Available since v2.4.0._
*/
function toPayable(address account) internal pure returns (address payable) {
return address(uint160(account));
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*
* _Available since v2.4.0._
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient");
// solhint-disable-next-line avoid-call-value
(bool success, ) = recipient.call{value:amount}("");
require(success, "Address: reverted");
}
}
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: < 0");
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves.
// A Solidity high level call has three parts:
// 1. The target address is checked to verify it contains contract code
// 2. The call itself is made, and success asserted
// 3. The return value is decoded, which in turn checks the size of the returned data.
// solhint-disable-next-line max-line-length
require(address(token).isContract(), "SafeERC20: !contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = address(token).call(data);
require(success, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: !succeed");
}
}
}
library Keep3rV1Library {
function getReserve(address pair, address reserve) external view returns (uint) {
(uint _r0, uint _r1,) = IUniswapV2Pair(pair).getReserves();
if (IUniswapV2Pair(pair).token0() == reserve) {
return _r0;
} else if (IUniswapV2Pair(pair).token1() == reserve) {
return _r1;
} else {
return 0;
}
}
}
interface IUniswapV2Pair {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);
function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
interface IGovernance {
function proposeJob(address job) external;
}
interface IKeep3rV1Helper {
function getQuoteLimit(uint gasUsed) external view returns (uint);
}
contract Keep3rV1 is ReentrancyGuard {
using SafeMath for uint;
using SafeERC20 for IERC20;
/// @notice Keep3r Helper to set max prices for the ecosystem
IKeep3rV1Helper public KPRH;
/// @notice EIP-20 token name for this token
string public constant name = "Keep3rV1";
/// @notice EIP-20 token symbol for this token
string public constant symbol = "KP3R";
/// @notice EIP-20 token decimals for this token
uint8 public constant decimals = 18;
/// @notice Total number of tokens in circulation
uint public totalSupply = 0; // Initial 0
/// @notice A record of each accounts delegate
mapping (address => address) public delegates;
/// @notice A record of votes checkpoints for each account, by index
mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;
/// @notice The number of checkpoints for each account
mapping (address => uint32) public numCheckpoints;
mapping (address => mapping (address => uint)) internal allowances;
mapping (address => uint) internal balances;
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint chainId,address verifyingContract)");
bytes32 public immutable DOMAINSEPARATOR;
/// @notice The EIP-712 typehash for the delegation struct used by the contract
bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint nonce,uint expiry)");
/// @notice The EIP-712 typehash for the permit struct used by the contract
bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint value,uint nonce,uint deadline)");
/// @notice A record of states for signing / validating signatures
mapping (address => uint) public nonces;
/// @notice An event thats emitted when an account changes its delegate
event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);
/// @notice An event thats emitted when a delegate account's vote balance changes
event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);
/// @notice A checkpoint for marking number of votes from a given block
struct Checkpoint {
uint32 fromBlock;
uint votes;
}
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) public {
_delegate(msg.sender, delegatee);
}
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) public {
bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", DOMAINSEPARATOR, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), "delegateBySig: sig");
require(nonce == nonces[signatory]++, "delegateBySig: nonce");
require(now <= expiry, "delegateBySig: expired");
_delegate(signatory, delegatee);
}
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view returns (uint) {
uint32 nCheckpoints = numCheckpoints[account];
return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
}
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint blockNumber) public view returns (uint) {
require(blockNumber < block.number, "getPriorVotes:");
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance
if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance
if (checkpoints[account][0].fromBlock > blockNumber) {
return 0;
}
uint32 lower = 0;
uint32 upper = nCheckpoints - 1;
while (upper > lower) {
uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
Checkpoint memory cp = checkpoints[account][center];
if (cp.fromBlock == blockNumber) {
return cp.votes;
} else if (cp.fromBlock < blockNumber) {
lower = center;
} else {
upper = center - 1;
}
}
return checkpoints[account][lower].votes;
}
function _delegate(address delegator, address delegatee) internal {
address currentDelegate = delegates[delegator];
uint delegatorBalance = votes[delegator].add(bonds[delegator][address(this)]);
delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
_moveDelegates(currentDelegate, delegatee, delegatorBalance);
}
function _moveDelegates(address srcRep, address dstRep, uint amount) internal {
if (srcRep != dstRep && amount > 0) {
if (srcRep != address(0)) {
uint32 srcRepNum = numCheckpoints[srcRep];
uint srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
uint srcRepNew = srcRepOld.sub(amount, "_moveVotes: underflows");
_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
}
if (dstRep != address(0)) {
uint32 dstRepNum = numCheckpoints[dstRep];
uint dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
uint dstRepNew = dstRepOld.add(amount);
_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
}
}
}
function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint oldVotes, uint newVotes) internal {
uint32 blockNumber = safe32(block.number, "_writeCheckpoint: 32 bits");
if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
}
function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {
require(n < 2**32, errorMessage);
return uint32(n);
}
/// @notice The standard EIP-20 transfer event
event Transfer(address indexed from, address indexed to, uint amount);
/// @notice The standard EIP-20 approval event
event Approval(address indexed owner, address indexed spender, uint amount);
/// @notice Submit a job
event SubmitJob(address indexed job, address indexed liquidity, address indexed provider, uint block, uint credit);
/// @notice Apply credit to a job
event ApplyCredit(address indexed job, address indexed liquidity, address indexed provider, uint block, uint credit);
/// @notice Remove credit for a job
event RemoveJob(address indexed job, address indexed liquidity, address indexed provider, uint block, uint credit);
/// @notice Unbond credit for a job
event UnbondJob(address indexed job, address indexed liquidity, address indexed provider, uint block, uint credit);
/// @notice Added a Job
event JobAdded(address indexed job, uint block, address governance);
/// @notice Removed a job
event JobRemoved(address indexed job, uint block, address governance);
/// @notice Worked a job
event KeeperWorked(address indexed credit, address indexed job, address indexed keeper, uint block, uint amount);
/// @notice Keeper bonding
event KeeperBonding(address indexed keeper, uint block, uint active, uint bond);
/// @notice Keeper bonded
event KeeperBonded(address indexed keeper, uint block, uint activated, uint bond);
/// @notice Keeper unbonding
event KeeperUnbonding(address indexed keeper, uint block, uint deactive, uint bond);
/// @notice Keeper unbound
event KeeperUnbound(address indexed keeper, uint block, uint deactivated, uint bond);
/// @notice Keeper slashed
event KeeperSlashed(address indexed keeper, address indexed slasher, uint block, uint slash);
/// @notice Keeper disputed
event KeeperDispute(address indexed keeper, uint block);
/// @notice Keeper resolved
event KeeperResolved(address indexed keeper, uint block);
event AddCredit(address indexed credit, address indexed job, address indexed creditor, uint block, uint amount);
/// @notice 1 day to bond to become a keeper
uint constant public BOND = 3 days;
/// @notice 14 days to unbond to remove funds from being a keeper
uint constant public UNBOND = 14 days;
/// @notice 3 days till liquidity can be bound
uint constant public LIQUIDITYBOND = 3 days;
/// @notice direct liquidity fee 0.3%
uint constant public FEE = 30;
uint constant public BASE = 10000;
/// @notice address used for ETH transfers
address constant public ETH = address(0xE);
/// @notice tracks all current bondings (time)
mapping(address => mapping(address => uint)) public bondings;
/// @notice tracks all current unbondings (time)
mapping(address => mapping(address => uint)) public unbondings;
/// @notice allows for partial unbonding
mapping(address => mapping(address => uint)) public partialUnbonding;
/// @notice tracks all current pending bonds (amount)
mapping(address => mapping(address => uint)) public pendingbonds;
/// @notice tracks how much a keeper has bonded
mapping(address => mapping(address => uint)) public bonds;
/// @notice tracks underlying votes (that don't have bond)
mapping(address => uint) public votes;
/// @notice total bonded (totalSupply for bonds)
uint public totalBonded = 0;
/// @notice tracks when a keeper was first registered
mapping(address => uint) public firstSeen;
/// @notice tracks if a keeper has a pending dispute
mapping(address => bool) public disputes;
/// @notice tracks last job performed for a keeper
mapping(address => uint) public lastJob;
/// @notice tracks the total job executions for a keeper
mapping(address => uint) public workCompleted;
/// @notice list of all jobs registered for the keeper system
mapping(address => bool) public jobs;
/// @notice the current credit available for a job
mapping(address => mapping(address => uint)) public credits;
/// @notice the balances for the liquidity providers
mapping(address => mapping(address => mapping(address => uint))) public liquidityProvided;
/// @notice liquidity unbonding days
mapping(address => mapping(address => mapping(address => uint))) public liquidityUnbonding;
/// @notice liquidity unbonding amounts
mapping(address => mapping(address => mapping(address => uint))) public liquidityAmountsUnbonding;
/// @notice job proposal delay
mapping(address => uint) public jobProposalDelay;
/// @notice liquidity apply date
mapping(address => mapping(address => mapping(address => uint))) public liquidityApplied;
/// @notice liquidity amount to apply
mapping(address => mapping(address => mapping(address => uint))) public liquidityAmount;
/// @notice list of all current keepers
mapping(address => bool) public keepers;
/// @notice blacklist of keepers not allowed to participate
mapping(address => bool) public blacklist;
/// @notice traversable array of keepers to make external management easier
address[] public keeperList;
/// @notice traversable array of jobs to make external management easier
address[] public jobList;
/// @notice governance address for the governance contract
address public governance;
address public pendingGovernance;
/// @notice the liquidity token supplied by users paying for jobs
mapping(address => bool) public liquidityAccepted;
address[] public liquidityPairs;
uint internal _gasUsed;
constructor(address _kph) public {
// Set governance for this token
governance = msg.sender;
DOMAINSEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), _getChainId(), address(this)));
KPRH = IKeep3rV1Helper(_kph);
}
/**
* @notice Add ETH credit to a job to be paid out for work
* @param job the job being credited
*/
function addCreditETH(address job) external payable {
require(jobs[job], "addCreditETH: !job");
uint _fee = msg.value.mul(FEE).div(BASE);
credits[job][ETH] = credits[job][ETH].add(msg.value.sub(_fee));
payable(governance).transfer(_fee);
emit AddCredit(ETH, job, msg.sender, block.number, msg.value);
}
/**
* @notice Add credit to a job to be paid out for work
* @param credit the credit being assigned to the job
* @param job the job being credited
* @param amount the amount of credit being added to the job
*/
function addCredit(address credit, address job, uint amount) external nonReentrant {
require(jobs[job], "addCreditETH: !job");
uint _before = IERC20(credit).balanceOf(address(this));
IERC20(credit).safeTransferFrom(msg.sender, address(this), amount);
uint _received = IERC20(credit).balanceOf(address(this)).sub(_before);
uint _fee = _received.mul(FEE).div(BASE);
credits[job][credit] = credits[job][credit].add(_received.sub(_fee));
IERC20(credit).safeTransfer(governance, _fee);
emit AddCredit(credit, job, msg.sender, block.number, _received);
}
/**
* @notice Add non transferable votes for governance
* @param voter to add the votes to
* @param amount of votes to add
*/
function addVotes(address voter, uint amount) external {
require(msg.sender == governance, "addVotes: !gov");
_activate(voter, address(this));
votes[voter] = votes[voter].add(amount);
totalBonded = totalBonded.add(amount);
_moveDelegates(address(0), delegates[voter], amount);
}
/**
* @notice Remove non transferable votes for governance
* @param voter to subtract the votes
* @param amount of votes to remove
*/
function removeVotes(address voter, uint amount) external {
require(msg.sender == governance, "addVotes: !gov");
votes[voter] = votes[voter].sub(amount);
totalBonded = totalBonded.sub(amount);
_moveDelegates(delegates[voter], address(0), amount);
}
/**
* @notice Add credit to a job to be paid out for work
* @param job the job being credited
* @param amount the amount of credit being added to the job
*/
function addKPRCredit(address job, uint amount) external {
require(msg.sender == governance, "addKPRCredit: !gov");
require(jobs[job], "addKPRCredit: !job");
credits[job][address(this)] = credits[job][address(this)].add(amount);
_mint(address(this), amount);
emit AddCredit(address(this), job, msg.sender, block.number, amount);
}
/**
* @notice Approve a liquidity pair for being accepted in future
* @param liquidity the liquidity no longer accepted
*/
function approveLiquidity(address liquidity) external {
require(msg.sender == governance, "approveLiquidity: !gov");
require(!liquidityAccepted[liquidity], "approveLiquidity: !pair");
liquidityAccepted[liquidity] = true;
liquidityPairs.push(liquidity);
}
/**
* @notice Revoke a liquidity pair from being accepted in future
* @param liquidity the liquidity no longer accepted
*/
function revokeLiquidity(address liquidity) external {
require(msg.sender == governance, "revokeLiquidity: !gov");
liquidityAccepted[liquidity] = false;
}
/**
* @notice Displays all accepted liquidity pairs
*/
function pairs() external view returns (address[] memory) {
return liquidityPairs;
}
/**
* @notice Allows liquidity providers to submit jobs
* @param liquidity the liquidity being added
* @param job the job to assign credit to
* @param amount the amount of liquidity tokens to use
*/
function addLiquidityToJob(address liquidity, address job, uint amount) external nonReentrant {
require(liquidityAccepted[liquidity], "addLiquidityToJob: !pair");
IERC20(liquidity).safeTransferFrom(msg.sender, address(this), amount);
liquidityProvided[msg.sender][liquidity][job] = liquidityProvided[msg.sender][liquidity][job].add(amount);
liquidityApplied[msg.sender][liquidity][job] = now.add(LIQUIDITYBOND);
liquidityAmount[msg.sender][liquidity][job] = liquidityAmount[msg.sender][liquidity][job].add(amount);
if (!jobs[job] && jobProposalDelay[job] < now) {
IGovernance(governance).proposeJob(job);
jobProposalDelay[job] = now.add(UNBOND);
}
emit SubmitJob(job, liquidity, msg.sender, block.number, amount);
}
/**
* @notice Applies the credit provided in addLiquidityToJob to the job
* @param provider the liquidity provider
* @param liquidity the pair being added as liquidity
* @param job the job that is receiving the credit
*/
function applyCreditToJob(address provider, address liquidity, address job) external {
require(liquidityAccepted[liquidity], "addLiquidityToJob: !pair");
require(liquidityApplied[provider][liquidity][job] != 0, "credit: no bond");
require(liquidityApplied[provider][liquidity][job] < now, "credit: bonding");
uint _liquidity = Keep3rV1Library.getReserve(liquidity, address(this));
uint _credit = _liquidity.mul(liquidityAmount[provider][liquidity][job]).div(IERC20(liquidity).totalSupply());
_mint(address(this), _credit);
credits[job][address(this)] = credits[job][address(this)].add(_credit);
liquidityAmount[provider][liquidity][job] = 0;
emit ApplyCredit(job, liquidity, provider, block.number, _credit);
}
/**
* @notice Unbond liquidity for a job
* @param liquidity the pair being unbound
* @param job the job being unbound from
* @param amount the amount of liquidity being removed
*/
function unbondLiquidityFromJob(address liquidity, address job, uint amount) external {
require(liquidityAmount[msg.sender][liquidity][job] == 0, "credit: pending credit");
liquidityUnbonding[msg.sender][liquidity][job] = now.add(UNBOND);
liquidityAmountsUnbonding[msg.sender][liquidity][job] = liquidityAmountsUnbonding[msg.sender][liquidity][job].add(amount);
require(liquidityAmountsUnbonding[msg.sender][liquidity][job] <= liquidityProvided[msg.sender][liquidity][job], "unbondLiquidityFromJob: insufficient funds");
uint _liquidity = Keep3rV1Library.getReserve(liquidity, address(this));
uint _credit = _liquidity.mul(amount).div(IERC20(liquidity).totalSupply());
if (_credit > credits[job][address(this)]) {
_burn(address(this), credits[job][address(this)]);
credits[job][address(this)] = 0;
} else {
_burn(address(this), _credit);
credits[job][address(this)] = credits[job][address(this)].sub(_credit);
}
emit UnbondJob(job, liquidity, msg.sender, block.number, amount);
}
/**
* @notice Allows liquidity providers to remove liquidity
* @param liquidity the pair being unbound
* @param job the job being unbound from
*/
function removeLiquidityFromJob(address liquidity, address job) external {
require(liquidityUnbonding[msg.sender][liquidity][job] != 0, "removeJob: unbond");
require(liquidityUnbonding[msg.sender][liquidity][job] < now, "removeJob: unbonding");
uint _amount = liquidityAmountsUnbonding[msg.sender][liquidity][job];
liquidityProvided[msg.sender][liquidity][job] = liquidityProvided[msg.sender][liquidity][job].sub(_amount);
liquidityAmountsUnbonding[msg.sender][liquidity][job] = 0;
IERC20(liquidity).safeTransfer(msg.sender, _amount);
emit RemoveJob(job, liquidity, msg.sender, block.number, _amount);
}
/**
* @notice Allows governance to mint new tokens to treasury
* @param amount the amount of tokens to mint to treasury
*/
function mint(uint amount) external {
require(msg.sender == governance, "mint: !gov");
_mint(governance, amount);
}
/**
* @notice burn owned tokens
* @param amount the amount of tokens to burn
*/
function burn(uint amount) external {
_burn(msg.sender, amount);
}
function _mint(address dst, uint amount) internal {
// mint the amount
totalSupply = totalSupply.add(amount);
// transfer the amount to the recipient
balances[dst] = balances[dst].add(amount);
emit Transfer(address(0), dst, amount);
}
function _burn(address dst, uint amount) internal {
require(dst != address(0), "_burn: zero address");
balances[dst] = balances[dst].sub(amount, "_burn: exceeds balance");
totalSupply = totalSupply.sub(amount);
emit Transfer(dst, address(0), amount);
}
/**
* @notice Implemented by jobs to show that a keeper performed work
* @param keeper address of the keeper that performed the work
*/
function worked(address keeper) external {
workReceipt(keeper, KPRH.getQuoteLimit(_gasUsed.sub(gasleft())));
}
/**
* @notice Implemented by jobs to show that a keeper performed work
* @param keeper address of the keeper that performed the work
* @param amount the reward that should be allocated
*/
function workReceipt(address keeper, uint amount) public {
require(jobs[msg.sender], "workReceipt: !job");
require(amount <= KPRH.getQuoteLimit(_gasUsed.sub(gasleft())), "workReceipt: max limit");
credits[msg.sender][address(this)] = credits[msg.sender][address(this)].sub(amount, "workReceipt: insuffient funds");
lastJob[keeper] = now;
_reward(keeper, amount);
workCompleted[keeper] = workCompleted[keeper].add(amount);
emit KeeperWorked(address(this), msg.sender, keeper, block.number, amount);
}
/**
* @notice Implemented by jobs to show that a keeper performed work
* @param credit the asset being awarded to the keeper
* @param keeper address of the keeper that performed the work
* @param amount the reward that should be allocated
*/
function receipt(address credit, address keeper, uint amount) external {
require(jobs[msg.sender], "receipt: !job");
credits[msg.sender][credit] = credits[msg.sender][credit].sub(amount, "workReceipt: insuffient funds");
lastJob[keeper] = now;
IERC20(credit).safeTransfer(keeper, amount);
emit KeeperWorked(credit, msg.sender, keeper, block.number, amount);
}
/**
* @notice Implemented by jobs to show that a keeper performed work
* @param keeper address of the keeper that performed the work
* @param amount the amount of ETH sent to the keeper
*/
function receiptETH(address keeper, uint amount) external {
require(jobs[msg.sender], "receipt: !job");
credits[msg.sender][ETH] = credits[msg.sender][ETH].sub(amount, "workReceipt: insuffient funds");
lastJob[keeper] = now;
payable(keeper).transfer(amount);
emit KeeperWorked(ETH, msg.sender, keeper, block.number, amount);
}
function _reward(address _from, uint _amount) internal {
bonds[_from][address(this)] = bonds[_from][address(this)].add(_amount);
totalBonded = totalBonded.add(_amount);
_moveDelegates(address(0), delegates[_from], _amount);
emit Transfer(msg.sender, _from, _amount);
}
function _bond(address bonding, address _from, uint _amount) internal {
bonds[_from][bonding] = bonds[_from][bonding].add(_amount);
if (bonding == address(this)) {
totalBonded = totalBonded.add(_amount);
_moveDelegates(address(0), delegates[_from], _amount);
}
}
function _unbond(address bonding, address _from, uint _amount) internal {
bonds[_from][bonding] = bonds[_from][bonding].sub(_amount);
if (bonding == address(this)) {
totalBonded = totalBonded.sub(_amount);
_moveDelegates(delegates[_from], address(0), _amount);
}
}
/**
* @notice Allows governance to add new job systems
* @param job address of the contract for which work should be performed
*/
function addJob(address job) external {
require(msg.sender == governance, "addJob: !gov");
require(!jobs[job], "addJob: job known");
jobs[job] = true;
jobList.push(job);
emit JobAdded(job, block.number, msg.sender);
}
/**
* @notice Full listing of all jobs ever added
* @return array blob
*/
function getJobs() external view returns (address[] memory) {
return jobList;
}
/**
* @notice Allows governance to remove a job from the systems
* @param job address of the contract for which work should be performed
*/
function removeJob(address job) external {
require(msg.sender == governance, "removeJob: !gov");
jobs[job] = false;
emit JobRemoved(job, block.number, msg.sender);
}
/**
* @notice Allows governance to change the Keep3rHelper for max spend
* @param _kprh new helper address to set
*/
function setKeep3rHelper(IKeep3rV1Helper _kprh) external {
require(msg.sender == governance, "setKeep3rHelper: !gov");
KPRH = _kprh;
}
/**
* @notice Allows governance to change governance (for future upgradability)
* @param _governance new governance address to set
*/
function setGovernance(address _governance) external {
require(msg.sender == governance, "setGovernance: !gov");
pendingGovernance = _governance;
}
/**
* @notice Allows pendingGovernance to accept their role as governance (protection pattern)
*/
function acceptGovernance() external {
require(msg.sender == pendingGovernance, "acceptGovernance: !pendingGov");
governance = pendingGovernance;
}
/**
* @notice confirms if the current keeper is registered, can be used for general (non critical) functions
* @param keeper the keeper being investigated
* @return true/false if the address is a keeper
*/
function isKeeper(address keeper) external returns (bool) {
_gasUsed = gasleft();
return keepers[keeper];
}
/**
* @notice confirms if the current keeper is registered and has a minimum bond, should be used for protected functions
* @param keeper the keeper being investigated
* @param minBond the minimum requirement for the asset provided in bond
* @param earned the total funds earned in the keepers lifetime
* @param age the age of the keeper in the system
* @return true/false if the address is a keeper and has more than the bond
*/
function isMinKeeper(address keeper, uint minBond, uint earned, uint age) external returns (bool) {
_gasUsed = gasleft();
return keepers[keeper]
&& bonds[keeper][address(this)].add(votes[keeper]) >= minBond
&& workCompleted[keeper] >= earned
&& now.sub(firstSeen[keeper]) >= age;
}
/**
* @notice confirms if the current keeper is registered and has a minimum bond, should be used for protected functions
* @param keeper the keeper being investigated
* @param bond the bound asset being evaluated
* @param minBond the minimum requirement for the asset provided in bond
* @param earned the total funds earned in the keepers lifetime
* @param age the age of the keeper in the system
* @return true/false if the address is a keeper and has more than the bond
*/
function isBondedKeeper(address keeper, address bond, uint minBond, uint earned, uint age) external returns (bool) {
_gasUsed = gasleft();
return keepers[keeper]
&& bonds[keeper][bond] >= minBond
&& workCompleted[keeper] >= earned
&& now.sub(firstSeen[keeper]) >= age;
}
/**
* @notice begin the bonding process for a new keeper
* @param bonding the asset being bound
* @param amount the amount of bonding asset being bound
*/
function bond(address bonding, uint amount) external nonReentrant {
require(!blacklist[msg.sender], "bond: blacklisted");
bondings[msg.sender][bonding] = now.add(BOND);
if (bonding == address(this)) {
_transferTokens(msg.sender, address(this), amount);
} else {
uint _before = IERC20(bonding).balanceOf(address(this));
IERC20(bonding).safeTransferFrom(msg.sender, address(this), amount);
amount = IERC20(bonding).balanceOf(address(this)).sub(_before);
}
pendingbonds[msg.sender][bonding] = pendingbonds[msg.sender][bonding].add(amount);
emit KeeperBonding(msg.sender, block.number, bondings[msg.sender][bonding], amount);
}
/**
* @notice get full list of keepers in the system
*/
function getKeepers() external view returns (address[] memory) {
return keeperList;
}
/**
* @notice allows a keeper to activate/register themselves after bonding
* @param bonding the asset being activated as bond collateral
*/
function activate(address bonding) external {
require(!blacklist[msg.sender], "activate: blacklisted");
require(bondings[msg.sender][bonding] != 0 && bondings[msg.sender][bonding] < now, "activate: bonding");
_activate(msg.sender, bonding);
}
function _activate(address keeper, address bonding) internal {
if (firstSeen[keeper] == 0) {
firstSeen[keeper] = now;
keeperList.push(keeper);
lastJob[keeper] = now;
}
keepers[keeper] = true;
_bond(bonding, keeper, pendingbonds[keeper][bonding]);
pendingbonds[keeper][bonding] = 0;
emit KeeperBonded(keeper, block.number, block.timestamp, bonds[keeper][bonding]);
}
/**
* @notice begin the unbonding process to stop being a keeper
* @param bonding the asset being unbound
* @param amount allows for partial unbonding
*/
function unbond(address bonding, uint amount) external {
unbondings[msg.sender][bonding] = now.add(UNBOND);
_unbond(bonding, msg.sender, amount);
partialUnbonding[msg.sender][bonding] = partialUnbonding[msg.sender][bonding].add(amount);
emit KeeperUnbonding(msg.sender, block.number, unbondings[msg.sender][bonding], amount);
}
/**
* @notice withdraw funds after unbonding has finished
* @param bonding the asset to withdraw from the bonding pool
*/
function withdraw(address bonding) external nonReentrant {
require(unbondings[msg.sender][bonding] != 0 && unbondings[msg.sender][bonding] < now, "withdraw: unbonding");
require(!disputes[msg.sender], "withdraw: disputes");
if (bonding == address(this)) {
_transferTokens(address(this), msg.sender, partialUnbonding[msg.sender][bonding]);
} else {
IERC20(bonding).safeTransfer(msg.sender, partialUnbonding[msg.sender][bonding]);
}
emit KeeperUnbound(msg.sender, block.number, block.timestamp, partialUnbonding[msg.sender][bonding]);
partialUnbonding[msg.sender][bonding] = 0;
}
/**
* @notice allows governance to create a dispute for a given keeper
* @param keeper the address in dispute
*/
function dispute(address keeper) external {
require(msg.sender == governance, "dispute: !gov");
disputes[keeper] = true;
emit KeeperDispute(keeper, block.number);
}
/**
* @notice allows governance to slash a keeper based on a dispute
* @param bonded the asset being slashed
* @param keeper the address being slashed
* @param amount the amount being slashed
*/
function slash(address bonded, address keeper, uint amount) public nonReentrant {
require(msg.sender == governance, "slash: !gov");
if (bonded == address(this)) {
_transferTokens(address(this), governance, amount);
} else {
IERC20(bonded).safeTransfer(governance, amount);
}
_unbond(bonded, keeper, amount);
disputes[keeper] = false;
emit KeeperSlashed(keeper, msg.sender, block.number, amount);
}
/**
* @notice blacklists a keeper from participating in the network
* @param keeper the address being slashed
*/
function revoke(address keeper) external {
require(msg.sender == governance, "slash: !gov");
keepers[keeper] = false;
blacklist[keeper] = true;
slash(address(this), keeper, bonds[keeper][address(this)]);
}
/**
* @notice allows governance to resolve a dispute on a keeper
* @param keeper the address cleared
*/
function resolve(address keeper) external {
require(msg.sender == governance, "resolve: !gov");
disputes[keeper] = false;
emit KeeperResolved(keeper, block.number);
}
/**
* @notice Get the number of tokens `spender` is approved to spend on behalf of `account`
* @param account The address of the account holding the funds
* @param spender The address of the account spending the funds
* @return The number of tokens approved
*/
function allowance(address account, address spender) external view returns (uint) {
return allowances[account][spender];
}
/**
* @notice Approve `spender` to transfer up to `amount` from `src`
* @dev This will overwrite the approval amount for `spender`
* and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
* @param spender The address of the account which may transfer tokens
* @param amount The number of tokens that are approved (2^256-1 means infinite)
* @return Whether or not the approval succeeded
*/
function approve(address spender, uint amount) public returns (bool) {
allowances[msg.sender][spender] = amount;
emit Approval(msg.sender, spender, amount);
return true;
}
/**
* @notice Triggers an approval from owner to spends
* @param owner The address to approve from
* @param spender The address to be approved
* @param amount The number of tokens that are approved (2^256-1 means infinite)
* @param deadline The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function permit(address owner, address spender, uint amount, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, amount, nonces[owner]++, deadline));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", DOMAINSEPARATOR, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), "permit: signature");
require(signatory == owner, "permit: unauthorized");
require(now <= deadline, "permit: expired");
allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @notice Get the number of tokens held by the `account`
* @param account The address of the account to get the balance of
* @return The number of tokens held
*/
function balanceOf(address account) external view returns (uint) {
return balances[account];
}
/**
* @notice Transfer `amount` tokens from `msg.sender` to `dst`
* @param dst The address of the destination account
* @param amount The number of tokens to transfer
* @return Whether or not the transfer succeeded
*/
function transfer(address dst, uint amount) public returns (bool) {
_transferTokens(msg.sender, dst, amount);
return true;
}
/**
* @notice Transfer `amount` tokens from `src` to `dst`
* @param src The address of the source account
* @param dst The address of the destination account
* @param amount The number of tokens to transfer
* @return Whether or not the transfer succeeded
*/
function transferFrom(address src, address dst, uint amount) external returns (bool) {
address spender = msg.sender;
uint spenderAllowance = allowances[src][spender];
if (spender != src && spenderAllowance != uint(-1)) {
uint newAllowance = spenderAllowance.sub(amount, "transferFrom: exceeds spender allowance");
allowances[src][spender] = newAllowance;
emit Approval(src, spender, newAllowance);
}
_transferTokens(src, dst, amount);
return true;
}
function _transferTokens(address src, address dst, uint amount) internal {
require(src != address(0), "_transferTokens: zero address");
require(dst != address(0), "_transferTokens: zero address");
balances[src] = balances[src].sub(amount, "_transferTokens: exceeds balance");
balances[dst] = balances[dst].add(amount, "_transferTokens: overflows");
emit Transfer(src, dst, amount);
}
function _getChainId() internal pure returns (uint) {
uint chainId;
assembly { chainId := chainid() }
return chainId;
}
}