module Octopoller

Constants

VERSION

Public Class Methods

poll(wait: 1, timeout: nil, retries: nil) { || ... } click to toggle source

Polls until success Re-runs when the block returns `:re_poll`

wait - The time delay in seconds between polls (default is 1 second)

- When given the argument `:exponentially` the action will be retried with exponetial backoff

timeout - The maximum number of seconds the poller will execute retries - The maximum number of times the action will be retried yield - A block that will execute, and if `:re_poll` is returned it will re-run

- Re-runs until something is returned or the timeout/retries is reached

raise - Raises an Octopoller::TimeoutError if the timeout is reached raise - Raises an Octopoller::TooManyAttemptsError if the retries is reached

# File lib/octopoller.rb, line 18
def poll(wait: 1, timeout: nil, retries: nil)
  Octopoller.validate_arguments(wait, timeout, retries)
  exponential_backoff = (wait == :exponentially)

  wait = 0.25 if exponential_backoff
  if timeout
    start = Time.now.utc
    while Time.now.utc < start + timeout
      block_value = yield
      return block_value unless block_value == :re_poll
      sleep wait
      wait *= 2 if exponential_backoff
    end
    raise TimeoutError, "Polling timed out paitently"
  else
    (retries + 1).times do
      block_value = yield
      return block_value unless block_value == :re_poll
      sleep wait
      wait *= 2 if exponential_backoff
    end
    raise TooManyAttemptsError, "Polled maximum number of attempts"
  end
end

validate_arguments(wait, timeout, retries) click to toggle source

# File lib/octopoller.rb, line 43
def self.validate_arguments(wait, timeout, retries)
  if (timeout.nil? && retries.nil?) || (timeout && retries)
    raise ArgumentError, "Must pass an argument to either `timeout` or `retries`"
  end
  exponential_backoff = wait == :exponentially
  raise ArgumentError, "Cannot wait backwards in time" unless exponential_backoff || wait.positive?
  raise ArgumentError, "Timed out without even being able to try" if timeout&.negative?
  raise ArgumentError, "Cannot retry something a negative number of times" if retries&.negative?
end

Private Instance Methods

poll(wait: 1, timeout: nil, retries: nil) { || ... } click to toggle source

Polls until success Re-runs when the block returns `:re_poll`

wait - The time delay in seconds between polls (default is 1 second)

- When given the argument `:exponentially` the action will be retried with exponetial backoff

- Re-runs until something is returned or the timeout/retries is reached

raise - Raises an Octopoller::TimeoutError if the timeout is reached raise - Raises an Octopoller::TooManyAttemptsError if the retries is reached

# File lib/octopoller.rb, line 18
def poll(wait: 1, timeout: nil, retries: nil)
  Octopoller.validate_arguments(wait, timeout, retries)
  exponential_backoff = (wait == :exponentially)

  wait = 0.25 if exponential_backoff
  if timeout
    start = Time.now.utc
    while Time.now.utc < start + timeout
      block_value = yield
      return block_value unless block_value == :re_poll
      sleep wait
      wait *= 2 if exponential_backoff
    end
    raise TimeoutError, "Polling timed out paitently"
  else
    (retries + 1).times do
      block_value = yield
      return block_value unless block_value == :re_poll
      sleep wait
      wait *= 2 if exponential_backoff
    end
    raise TooManyAttemptsError, "Polled maximum number of attempts"
  end
end