Contents

require 'faraday'



module Saddle::Middleware
  module Request

    # Catches exceptions and retries each request a limited number of times.
    #
    # By default, it retries 2 times and performs exponential backoff, starting
    # at 50ms
    class Retry < Faraday::Middleware
      def initialize(app, ignored_exceptions=[])
        super(app)
        @ignored_exceptions = ignored_exceptions
      end

      def call(env)
        retries = env[:request][:num_retries] || 2
        backoff = env[:request][:retry_backoff] || 0.050 # ms
        begin
          @app.call(self.class.deep_copy(env))
        rescue => e
          unless @ignored_exceptions.include?(e.class)
            # Retry a limited number of times
            if retries > 0
              retries -= 1
              sleep(backoff) if backoff > 0.0
              backoff *= 2
              retry
            end
          end
          # Re-raise if we're out of retries or it's not handled
          raise
        end
      end

      def self.deep_copy(value)
        if value.is_a?(Hash)
          result = value.clone
          value.each{|k, v| result[k] = deep_copy(v)}
          result
        elsif value.is_a?(Array)
          result = value.clone
          result.clear
          value.each{|v| result << deep_copy(v)}
          result
        else
          value
        end
      end
    end

  end
end

Version data entries

5 entries across 5 versions & 1 rubygems

Version	Path
saddle-0.0.12	lib/saddle/middleware/request/retry.rb
saddle-0.0.11	lib/saddle/middleware/request/retry.rb
saddle-0.0.10	lib/saddle/middleware/request/retry.rb
saddle-0.0.7	lib/saddle/middleware/request/retry.rb
saddle-0.0.6	lib/saddle/middleware/request/retry.rb