Class: Perf::MeterFactory

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/perf/meter_factory.rb

Overview

Very simple Perf::Meter factory and singleton management.

Useful to not have to pass around Perf::Meter objects and still be able to generate stats in various parts of the code. For complex situations where you have multiple Perf::Meter objects you might need to consider either creating a factory that fulfills your needs, or create Perf::Meter objects and pass them around or use this factory will well planned out key values so that you won’t have conflicts and overrides.

Example of usage where it would be inconvenient to pass around the Perf::Meter object from example to function2:

def example

Perf::MeterFactory.instance.get.measure(:function1)
  function1()
end

end

def function1()

..
function2()
..

end

def function2()

..
Perf::MeterFactory.instance.get.measure(:some_hot_code_in_function2)
  ...
end
..

end

Constant Summary collapse

DEFAULT_METER = 
:default

Instance Method Summary collapse

Constructor Details

#initialize ⇒ MeterFactory

Returns a new instance of MeterFactory.



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# File 'lib/perf/meter_factory.rb', line 41

def initialize
  @perf_meters       = {}
  @new_meter_options = {}
  @factory_options   = {:noop=>false}
end

Instance Method Details

#all ⇒ Object

Returns a hash of existing meters.



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# File 'lib/perf/meter_factory.rb', line 109

def all
  @perf_meters.dup
end

#clear_all! ⇒ Object

Clears the entire cache of meters.



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# File 'lib/perf/meter_factory.rb', line 121

def clear_all!
  @perf_meters.clear
end

#clear_factory_options! ⇒ Object

Clear factory options.



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# File 'lib/perf/meter_factory.rb', line 84

def clear_factory_options!
  @factory_options.clear
end

#clear_meter(key = DEFAULT_METER) ⇒ Object

Removes an existing meter from the cache



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# File 'lib/perf/meter_factory.rb', line 115

def clear_meter(key=DEFAULT_METER)
  @perf_meters.delete(key) if @perf_meters
end

#exists?(key = DEFAULT_METER) ⇒ Boolean

If you use set_new_meters_options, or if you pass options to Perf::MeterFactory.get, you are setting options only for if the meter is created. For this reason you might need to find out if the meter already exist.

Returns:

  • (Boolean) 


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# File 'lib/perf/meter_factory.rb', line 91

def exists?(key=DEFAULT_METER)
  !@perf_meters[key].nil?
end

#get(key = DEFAULT_METER, new_meter_options = nil) ⇒ Object

Returns a Perf::Meter with a given key, and creates it lazily if it doesn’t exist’. NOTE: The options are set ONLY the first time that get is called on a specific key.

After that the options will be ignored!



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# File 'lib/perf/meter_factory.rb', line 51

def get(key=DEFAULT_METER,new_meter_options=nil)
  if !@factory_options[:noop]
    # Creates a real meter
    @perf_meters[key] ||= Perf::Meter.new(new_meter_options || @new_meter_options)
  else
    # If noop is set, creates a no-nop version of the meter, unless a meter with this key has already been
    # created.
    @perf_meters[key] ||= Perf::NoOpMeter.new
  end
end

#meter(key = DEFAULT_METER) ⇒ Object

meter is like get, but if the meter doesn’t already exists it returns a NoOpMeter. You can use this every time that you want “somebody else” make the decision of what meter to use.



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# File 'lib/perf/meter_factory.rb', line 65

def meter(key=DEFAULT_METER)
  @perf_meters[key] ||= Perf::NoOpMeter.new
end

#no_op_instance ⇒ Object

Used by ProductionMeterFactory to return the instance ensuring that no Perf::Meters will be created if they do not exist.



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# File 'lib/perf/meter_factory.rb', line 128

def no_op_instance
  @factory_options[:noop] = true
  self
end

#set_default(meter) ⇒ Object

Sets the default meter.



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# File 'lib/perf/meter_factory.rb', line 103

def set_default(meter)
  set_meter(DEFAULT_METER,meter)
end

#set_factory_options(options) ⇒ Object

Set options for the factory behaviour.



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# File 'lib/perf/meter_factory.rb', line 78

def set_factory_options(options)
  @factory_options.merge!(options)
end

#set_meter(key, meter) ⇒ Object

Pushes a Perf::Meter into a key



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# File 'lib/perf/meter_factory.rb', line 97

def set_meter(key,meter)
  @perf_meters[key]=meter
end

#set_new_meters_options(options) ⇒ Object

To set options for new meters created by get, when specific options are not passed, you can do so with this method.



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# File 'lib/perf/meter_factory.rb', line 72

def set_new_meters_options(options)
  @new_meter_options.merge(options)
end