module DragonSkeleton::LongCalculation

Contains methods for defining and running long calculations that can be spread over multiple ticks.

Define a calculation with the LongCalculation.define method.

calculation = LongCalculation.define do
  result = 0
  1_000_000.times do |i|
    result += compute_something(i)
    LongCalculation.finish_step
  end
  result
end

It will be interrupted every time the LongCalculation.finish_step method is called during the calculation and will be resumed the next time the LongCalculationFiber#resume method is called on the calculation.

calculation.resume

Once finished, the result can be accessed with the LongCalculationFiber#result method.

result = calculation.result

The calculation can also be run completely with the LongCalculationFiber#finish method. Or to run as many steps as possible in a given amount of milliseconds, use the LongCalculationFiber#run_for_ms method.

Public Class Methods

define() { || ... } click to toggle source

Define a long calculation with many steps and returns it as a LongCalculationFiber.

# File lib/dragon_skeleton/long_calculation.rb, line 30
def define
  fiber = Fiber.new do
    result = yield
    Fiber.current.result = result
  end
  fiber.extend LongCalculationFiber
  fiber
end

finish_step() click to toggle source

Call this inside a long calculation to signify that one step of the calculation has finished.

The calculation will be resumed the next time the LongCalculationFiber#resume method is called on the calculation.

# File lib/dragon_skeleton/long_calculation.rb, line 44
def finish_step
  return unless inside_calculation?
  return unless Fiber.current.yield_strategy.should_yield?

  Fiber.current.yield_strategy = nil
  Fiber.yield
end

inside_calculation?() click to toggle source

Returns true if the current code is running inside a long calculation.

# File lib/dragon_skeleton/long_calculation.rb, line 53
def inside_calculation?
  Fiber.current.respond_to? :result
end