Class: Saddle::Middleware::Request::Retry

Inherits:
Faraday::Middleware
  • Object
show all
Defined in:
lib/saddle/middleware/request/retry.rb

Overview

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

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

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app, ignored_exceptions = []) ⇒ Retry

Returns a new instance of Retry.



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# File 'lib/saddle/middleware/request/retry.rb', line 14

def initialize(app, ignored_exceptions=[])
  super(app)
  @ignored_exceptions = ignored_exceptions
end

Class Method Details

.deep_copy(value) ⇒ Object 



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# File 'lib/saddle/middleware/request/retry.rb', line 42

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

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/saddle/middleware/request/retry.rb', line 19

def call(env)
  retries = env[:request][:num_retries] || 0
  backoff = env[:request][: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[:request][: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