Class: Retries

Inherits:
Object
  • Object
show all
Defined in:
lib/robustserver.rb

Overview

Description

Counts retries ot something. If the retries are to often in a short time, you shouldn’t retry again.

Examples

Strings aren’t Integers and 2*“Text” will raise TypeError.

retries = Retry.new 5, 1 begin array_of_ints_and_some_strings.each do |i| puts 2*i end rescue TypeError retries.retry? and retry raise $! end

Retry.new( 10, 30).run( ConnectionLost) do try_to_connect_to_db try_query end

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(max = nil, range = nil) ⇒ Retries

max: How many retries in range-time are allowed maximal. range: In which time-range are these retries are allowed



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# File 'lib/robustserver.rb', line 65

def initialize max = nil, range = nil
	@max, @range, @count, @last = max || 10, range || 10, 0, Time.now
end

Instance Attribute Details

#count ⇒ Object (readonly)

Returns the value of attribute count.



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# File 'lib/robustserver.rb', line 61

def count
  @count
end

#last ⇒ Object (readonly)

Returns the value of attribute last.



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# File 'lib/robustserver.rb', line 61

def last
  @last
end

#max ⇒ Object

Returns the value of attribute max.



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# File 'lib/robustserver.rb', line 60

def max
  @max
end

#range ⇒ Object

Returns the value of attribute range.



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# File 'lib/robustserver.rb', line 60

def range
  @range
end

Instance Method Details

#retry? ⇒ Boolean

Counts retries on every call. If these retries are to often - max times in range - it will return false else true. Now you can say: “I give up, to many retries, it seems it doesn’t work.”

Returns:

  • (Boolean) 


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# File 'lib/robustserver.rb', line 73

def retry?
	@count = @last + @range > Time.now ? @count + 1 : 1
	@last = Time.now
	@count < @max
end

#run(ex = nil, &e) ⇒ Object

Automatical retrieing on raised exceptions in block. ex: Your expected Esception you will rescue. Default: Object, so realy everything.

Example: Retries.new( 10, 30).run ArgumentError do something_do_which_could_raise_exception ArgumentError end

This will retry maximal 10 times in 30 seconds to Call this block. But only rescues ArgumentError! Every other Error it will ignore and throws Exception. No retry.



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# File 'lib/robustserver.rb', line 87

def run ex = nil, &e
	ex ||= Object
	begin e.call *args
	rescue ex
		retries.retry? and retry
	end
end