class AttemptThis::AttemptObject
Retry policy implementation. This class is internal and is not supposed to be used outside of the module.
Public Class Methods
get_object(id_or_enumerator)
click to toggle source
# File lib/attempt_this/attempt_object.rb, line 15 def self.get_object(id_or_enumerator) impl = @@scenarios[id_or_enumerator] impl ||= AttemptObject.new(id_or_enumerator) impl end
new(enumerator)
click to toggle source
Initializes object with enumerator.
# File lib/attempt_this/attempt_object.rb, line 22 def initialize(enumerator) @enumerator = enumerator end
reset()
click to toggle source
Resets all static data.
# File lib/attempt_this/attempt_object.rb, line 11 def self.reset @@scenarios = {} end
Public Instance Methods
and_default_to(default_method, &block)
click to toggle source
Specifies default method that should be called after all attempts have failed.
# File lib/attempt_this/attempt_object.rb, line 75 def and_default_to(default_method, &block) raise(ArgumentError, 'Default method is nil!') unless default_method raise(ArgumentError, 'Default method has already been specified!') if @default_method @default_method = default_method attempt(block) end
attempt(block)
click to toggle source
Executes the code block.
# File lib/attempt_this/attempt_object.rb, line 27 def attempt(block) # Returning self will allow chaining calls return self unless block return block.call unless AttemptThis.enabled? apply_defaults # Retriable attempts require special error handling result = each_retriable_attempt do return attempt_with_reset(&block) end # Final attempt if (result != :empty) @delay_policy.call unless result == :skipped final_attempt(&block) end end
scenario(id)
click to toggle source
Creates a scenario with the given id.
# File lib/attempt_this/attempt_object.rb, line 108 def scenario(id) raise(ArgumentError, 'Nil id!') if id.nil? raise(ArgumentError, "There is already a scenario with id #{id}") if @@scenarios.has_key?(id) @@scenarios[id] = self end
with_binary_backoff(initial_delay, &block)
click to toggle source
Specifies delay which doubles between failed attempts.
# File lib/attempt_this/attempt_object.rb, line 84 def with_binary_backoff(initial_delay, &block) raise(ArgumentError, "Delay should be a number; got ${initial_delay}!") unless initial_delay.is_a?(Numeric) raise(ArgumentError, "Delay should be a positive number; got #{initial_delay}!") unless initial_delay > 0 raise(ArgumentError, "Delay policy has already been specified!") if @delay_policy @delay_policy = BinaryBackoffPolicy.new(initial_delay) attempt(block) end
with_delay(delay, &block)
click to toggle source
Specifies delay in seconds between failed attempts.
# File lib/attempt_this/attempt_object.rb, line 47 def with_delay(delay, &block) # Delay should be either an integer or a range of integers. if (delay.is_a?(Numeric)) raise(ArgumentError, "Delay should be a non-negative number; got #{delay}!") unless delay >= 0 delay = delay..delay elsif delay.is_a?(Range) raise(ArgumentError, "Range members should be numbers; got #{delay}!") unless delay.first.is_a?(Numeric) && delay.last.is_a?(Numeric) raise(ArgumentError, "Range members should be non-negative; got #{delay}!") unless delay.first >= 0 && delay.last >= 0 raise(ArgumentError, "Range's end should be greater than or equal to range's start; got #{delay}!") unless delay.first <= delay.last else raise(ArgumentError, "Delay should be either an number or a range of numbers; got #{delay}!") end raise(ArgumentError, 'Delay policy has already been specified!') if @delay_policy @delay_policy = lambda{Kernel.sleep(delay.first + rand(delay.count))} attempt(block) end
with_filter(*exceptions, &block)
click to toggle source
Specifies exceptions
# File lib/attempt_this/attempt_object.rb, line 94 def with_filter(*exceptions, &block) raise(ArgumentError, "Empty exceptions list!") unless exceptions.size > 0 # Everything must be an exception. exceptions.each do |e| raise(ArgumentError, "Not an exception: #{e}!") unless e <= Exception end raise(ArgumentError, "Exception filter has already been specified!") if @exception_filter @exception_filter = ExceptionTypeFilter.new(exceptions) attempt(block) end
with_reset(reset_method, &block)
click to toggle source
Specifies reset method that will be called after each failed attempt.
# File lib/attempt_this/attempt_object.rb, line 66 def with_reset(reset_method, &block) raise(ArgumentError, 'Reset method is nil!') unless reset_method raise(ArgumentError, 'Reset method has already been speicifed!') if @reset_method @reset_method = reset_method attempt(block) end
Private Instance Methods
apply_defaults()
click to toggle source
# File lib/attempt_this/attempt_object.rb, line 126 def apply_defaults @delay_policy = lambda{} unless @delay_policy @reset_method = lambda{} unless @reset_method @exception_filter = ExceptionTypeFilter.new([StandardError]) unless @exception_filter end
attempt_with_reset(&block)
click to toggle source
# File lib/attempt_this/attempt_object.rb, line 150 def attempt_with_reset(&block) block.call rescue Exception => ex @reset_method.call raise end
each_retriable_attempt(&block)
click to toggle source
# File lib/attempt_this/attempt_object.rb, line 132 def each_retriable_attempt(&block) result = :empty @enumerator.each do if (result == :empty) result = :skipped next end @delay_policy.call unless result == :skipped result = :attempted begin block.call rescue Exception => ex raise unless @exception_filter.include?(ex) end end result end
final_attempt(&block)
click to toggle source
# File lib/attempt_this/attempt_object.rb, line 118 def final_attempt(&block) attempt_with_reset(&block) rescue Exception => ex raise unless @default_method raise unless @exception_filter.include?(ex) @default_method.call end