solidity/test/compilationTests/zeppelin/DayLimit.sol
2018-07-02 18:58:44 +02:00

76 lines
2.0 KiB
Solidity

pragma solidity ^0.4.11;
/**
* @title DayLimit
* @dev Base contract that enables methods to be protected by placing a linear limit (specifiable)
* on a particular resource per calendar day. Is multiowned to allow the limit to be altered.
*/
contract DayLimit {
uint256 public dailyLimit;
uint256 public spentToday;
uint256 public lastDay;
/**
* @dev Constructor that sets the passed value as a dailyLimit.
* @param _limit uint256 to represent the daily limit.
*/
constructor(uint256 _limit) {
dailyLimit = _limit;
lastDay = today();
}
/**
* @dev sets the daily limit. Does not alter the amount already spent today.
* @param _newLimit uint256 to represent the new limit.
*/
function _setDailyLimit(uint256 _newLimit) internal {
dailyLimit = _newLimit;
}
/**
* @dev Resets the amount already spent today.
*/
function _resetSpentToday() internal {
spentToday = 0;
}
/**
* @dev Checks to see if there is enough resource to spend today. If true, the resource may be expended.
* @param _value uint256 representing the amount of resource to spend.
* @return A boolean that is True if the resource was spended and false otherwise.
*/
function underLimit(uint256 _value) internal returns (bool) {
// reset the spend limit if we're on a different day to last time.
if (today() > lastDay) {
spentToday = 0;
lastDay = today();
}
// check to see if there's enough left - if so, subtract and return true.
// overflow protection // dailyLimit check
if (spentToday + _value >= spentToday && spentToday + _value <= dailyLimit) {
spentToday += _value;
return true;
}
return false;
}
/**
* @dev Private function to determine today's index
* @return uint256 of today's index.
*/
function today() private view returns (uint256) {
return now / 1 days;
}
/**
* @dev Simple modifier for daily limit.
*/
modifier limitedDaily(uint256 _value) {
if (!underLimit(_value)) {
throw;
}
_;
}
}