Class: CommandRetry

Inherits:
Object
  • Object
show all
Defined in:
lib/rails2ext/active_support/command_retry.rb

Overview

CommandRetry helps you repeat system commands when they are not successful for a given number of times (repeat once by default). If all repetitions fail, an error (default is RuntimeError) will be raised unless you passed in :fail => false option

It accepts also a on option, which can be a single exit code or an array of exit codes that will cause the block to be repeated. Other exit codes not included in the on array (if provided) will not cause repetitions and will will not raise errors.

Will retry 5 times, failing each time and eventually raise the default error:

CommandRetry.retry(:times => 5) { system 'bingobongo' }
#=> RuntimeError: #<RuntimeError:0x101d89648>

Will fail 5 times with exit code 7, eventually will raise custom error:

CommandRetry.retry(:fail => ArgumentError, :on => 7 :times => 5) do
  system 'curl localhost:123/notfound'
end

Will fail just once since exit code 7 is not included in on array, and will raise no error:

CommandRetry.retry(:on => 52, :times => 5) do
  system 'curl localhost:123/notfound'
end

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}, &block) ⇒ CommandRetry

Returns a new instance of CommandRetry.



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# File 'lib/rails2ext/active_support/command_retry.rb', line 40

def initialize(opts={}, &block)
  opts.symbolize_keys!
  @times   = opts[:times] || 2
  @fail    = opts[:fail]  || RuntimeError unless opts[:fail] == false
  @on      = Array.wrap(opts[:on]) if opts[:on]
  @command = block
end

Class Method Details

.retry(opts = {}, &block) ⇒ Object 



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# File 'lib/rails2ext/active_support/command_retry.rb', line 36

def self.retry(opts={}, &block)
  new(opts, &block).retry
end

Instance Method Details

#retry ⇒ Object 



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# File 'lib/rails2ext/active_support/command_retry.rb', line 48

def retry
  result = false
  status = 0
  @times.times do
    result = @command.call
    status = exit_status
    if should_break?(status)
      break
    end
  end

  if @fail && status != 0
    unless on_allows?(status)
      raise @fail, caller
    end
  end
  result
end