module Faraday # Catches exceptions and retries each request a limited number of times. # # By default, it retries 2 times and handles only timeout exceptions. It can # be configured with an arbitrary number of retries, a list of exceptions to # handle an a retry interval. # # Examples # # Faraday.new do |conn| # conn.request :retry, max: 2, interval: 0.05, # exceptions: [CustomException, 'Timeout::Error'] # conn.adapter ... # end class Request::Retry < Faraday::Middleware # Public: Initialize middleware # # Options: # max - Maximum number of retries (default: 2). # interval - Pause in seconds between retries (default: 0). # exceptions - The list of exceptions to handle. Exceptions can be # given as Class, Module, or String. (default: # [Errno::ETIMEDOUT, Timeout::Error, Error::TimeoutError]) def initialize(app, options = {}) super(app) @retries, options = options, {} if options.is_a? Integer @retries ||= options.fetch(:max, 2).to_i @sleep = options.fetch(:interval, 0).to_f to_handle = options.fetch(:exceptions) { [Errno::ETIMEDOUT, 'Timeout::Error', Error::TimeoutError] } @errmatch = build_exception_matcher Array(to_handle) end def call(env) retries = @retries begin @app.call(env) rescue @errmatch if retries > 0 retries -= 1 sleep @sleep if @sleep > 0 retry end raise end end # Private: construct an exception matcher object. # # An exception matcher for the rescue clause can usually be any object that # responds to `===`, but for Ruby 1.8 it has to be a Class or Module. def build_exception_matcher(exceptions) matcher = Module.new (class << matcher; self; end).class_eval do define_method(:===) do |error| exceptions.any? do |ex| if ex.is_a? Module then error.is_a? ex else error.class.to_s == ex.to_s end end end end matcher end end end