class Saddle::Middleware::Request::Retry

Catches exceptions and retries each request a limited number of times.

By default, it retries 0 times and performs exponential backoff, starting at 50ms

Public Class Methods

deep_copy(value) click to toggle source
# File lib/saddle/middleware/request/retry.rb, line 42
def self.deep_copy(value)
  if value.is_a?(Struct)
    result = value.clone
    value.each{|k, v| result.send("#{k}=", deep_copy(v))}
    result
  elsif 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
new(app, ignored_exceptions=[]) click to toggle source
Calls superclass method
# File lib/saddle/middleware/request/retry.rb, line 14
def initialize(app, ignored_exceptions=[])
  super(app)
  @ignored_exceptions = ignored_exceptions
end

Public Instance Methods

call(env) click to toggle source
# File lib/saddle/middleware/request/retry.rb, line 19
def call(env)
  retries = env[:saddle][:num_retries] || 0
  backoff = env[:saddle][:retry_backoff] || 0.050 # in seconds
  begin
    @app.call(self.class.deep_copy(env))
  rescue => e
    # Only retry for GET or if the request is marked as idempotent
    if env[:method] == :get || env[:saddle][:idempotent]
      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
    end
    # Re-raise if we're out of retries or it's not handled
    raise
  end
end