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_deriveStartFrom

Contract: JBFundingCycleStore​

The date that is the nearest multiple of the specified funding cycle's duration from its end.

Definition​

function _deriveStartFrom(JBFundingCycle memory _baseFundingCycle, uint256 _mustStartAtOrAfter)
  private
  pure
  returns (uint256 start) { ... }
  • Arguments:
    • _baseFundingCycle is The JBFundingCycle to base the calculation on.
    • _mustStartAtOrAfter is a date that the derived start must be on or come after.
  • The view function is private to this contract.
  • The view function does not alter state on the blockchain.
  • The function returns the next start time.

Body​

  1. A funding cycle with a duration of 0 can start as soon as possible.

    // A subsequent cycle to one with a duration of 0 should start as soon as possible.
    if (_baseFundingCycle.duration == 0) return _mustStartAtOrAfter;

  2. Get a reference to the start time of the cycle immediately following the base cycle. This is the base cycle's start time plus the base cycle's duration.

    // The time when the funding cycle immediately after the specified funding cycle starts.
    uint256 _nextImmediateStart = _baseFundingCycle.start + _baseFundingCycle.duration;

  3. If the next immediate start is allowed, it should be used. Otherwise, calculate a value depending on how much time has passed since the next immediate start.

    // If the next immediate start is now or in the future, return it.
    if (_nextImmediateStart >= _mustStartAtOrAfter) return _nextImmediateStart;

  4. Save a reference to the amount of seconds since the time when the funding cycle must start on or after, which results in a start time that might satisfy the specified constraints.

    // The amount of seconds since the `_mustStartAtOrAfter` time which results in a start time that might satisfy the specified constraints.
    uint256 _timeFromImmediateStartMultiple = (_mustStartAtOrAfter - _nextImmediateStart) %
      _baseFundingCycle.duration;

  5. Save a reference to the first possible start time.

    // A reference to the first possible start timestamp.
    start = _mustStartAtOrAfter - _timeFromImmediateStartMultiple;

  6. It's possible that the start time doesn't satisfy the specified constraints. If so, add increments of the funding cycle's duration as necessary to satisfy the threshold.

    // Add increments of duration as necessary to satisfy the threshold.
    while (_mustStartAtOrAfter > start) start = start + _baseFundingCycle.duration;