wait_for.rb

gistfile1.rb

module Fog 
  def self.wait_for(timeout=Fog.timeout, interval=Fog.interval, &block)
    duration = 0 
    start = Time.now
    retries = 0 
    until yield || duration > timeout
      sleep(wait_policy(retries += 1, interval))
      duration = Time.now - start
    end 
    if duration > timeout
      raise Errors::TimeoutError.new("The specified wait_for timeout (#{timeout} seconds) was exceeded")
    else
      { :duration => duration }
    end 
  end 
  
  def self.wait_policy(retries, policy)
    interval = policy.respond_to?(:call) ? policy.call(retries) : policy
    interval.to_f
  end 
end

__END__

#test

i = 0
r = Fog.wait_for(10, lambda { |retries| [2 ** (retries - 1), 32].min }) do
  i += 1
  i > 3 
end
puts r