Class: StatsD::Instrument::CompiledMetric::PrecompiledDatagram

Inherits:
Object
  • Object
show all
Defined in:
lib/statsd/instrument/compiled_metric.rb

Overview

A precompiled datagram that can quickly build the final StatsD datagram string using sprintf formatting with cached tag values.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(tag_values, datagram_blueprint, sample_rate) ⇒ PrecompiledDatagram

Returns a new instance of PrecompiledDatagram.

Parameters:

  • tag_values (Array) —

    The tag values to cache

  • datagram_blueprint (String) —

    The sprintf template

  • sample_rate (Float) —

    The sample rate (0.0-1.0)



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# File 'lib/statsd/instrument/compiled_metric.rb', line 390

def initialize(tag_values, datagram_blueprint, sample_rate)
  @tag_values = tag_values
  @datagram_blueprint = datagram_blueprint
  @sample_rate = sample_rate
end

Instance Attribute Details

#datagram_blueprint ⇒ Object (readonly)

Returns the value of attribute datagram_blueprint.



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# File 'lib/statsd/instrument/compiled_metric.rb', line 385

def datagram_blueprint
  @datagram_blueprint
end

#sample_rate ⇒ Object (readonly)

Returns the value of attribute sample_rate.



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# File 'lib/statsd/instrument/compiled_metric.rb', line 385

def sample_rate
  @sample_rate
end

#tag_values ⇒ Object (readonly)

Returns the value of attribute tag_values.



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# File 'lib/statsd/instrument/compiled_metric.rb', line 385

def tag_values
  @tag_values
end

Instance Method Details

#to_datagram(value) ⇒ String

Builds the final datagram string by substituting values into the blueprint

Parameters:

  • value (Numeric | Array[Numeric]) —

    The metric value

Returns:

  • (String) —

    The complete StatsD datagram



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# File 'lib/statsd/instrument/compiled_metric.rb', line 399

def to_datagram(value)
  packed_value = if value.is_a?(Array)
    value.join(":")
  else
    value.to_s
  end

  # Fast path: no tag values (static metrics)
  return @datagram_blueprint % packed_value if @tag_values.empty?

  # Sanitize string and symbol values (other types handled by sprintf %s)
  values = @tag_values.map do |arg|
    if arg.is_a?(String)
      /[|,]/.match?(arg) ? arg.tr("|,", "") : arg
    elsif arg.is_a?(Symbol)
      str = arg.to_s
      /[|,]/.match?(str) ? str.tr("|,", "") : str
    else
      arg
    end
  end

  # Prepend the metric value
  values.unshift(packed_value)

  # Use sprintf to build the final datagram
  @datagram_blueprint % values
end