Module: StatsD

Extended by:
StatsD
Included in:
StatsD
Defined in:
lib/statsd/instrument.rb,
lib/statsd/instrument/version.rb

Overview

The StatsD module contains low-level metrics for collecting metrics and sending them to the backend.

See Also:

Defined Under Namespace

Modules: Instrument

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#backend ⇒ StatsD::Instrument::Backend

The backend that is being used to emit the metrics.

Returns:

See Also:



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# File 'lib/statsd/instrument.rb', line 36

module StatsD
  extend self

  # The StatsD::Instrument module provides metaprogramming methods to instrument your methods with
  # StatsD metrics. E.g., yopu can create counters on how often a method is called, how often it is
  # successful, the duration of the methods call, etc.
  module Instrument

    # @private
    def self.generate_metric_name(metric_name, callee, *args)
      metric_name.respond_to?(:call) ? metric_name.call(callee, args).gsub('::', '.') : metric_name.gsub('::', '.')
    end

    if Process.respond_to?(:clock_gettime)
      # @private
      def self.duration
        start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        yield
        Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
      end
    else
      # @private
      def self.duration
        start = Time.now
        yield
        Time.now - start
      end
    end

    # Adds execution duration instrumentation to a method.
    #
    # @param method [Symbol] The name of the method to instrument.
    # @param name [String, #call] The name of the metric to use. You can also pass in a
    #    callable to dynamically generate a metric name
    # @param metric_options (see StatsD#measure)
    # @return [void]
    def statsd_measure(method, name, *metric_options)
      add_to_method(method, name, :measure) do |old_method, new_method, metric_name, *args|
        define_method(new_method) do |*args, &block|
          StatsD.measure(StatsD::Instrument.generate_metric_name(metric_name, self, *args), nil, *metric_options) { send(old_method, *args, &block) }
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # For successful calls, the metric <tt>[name].success</tt> will be incremented; for failed calls, the metric
    # name is <tt>[name].failure</tt>.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield You can pass a block to this method if you want to define yourself what is a successful call
    #   based on the return value of the method.
    # @yieldparam result The return value of the instrumented method.
    # @yieldreturn [Boolean] Return true iff the return value is consisered a success, false otherwise.
    # @return [void]
    # @see #statsd_count_if
    def statsd_count_success(method, name, *metric_options)
      add_to_method(method, name, :count_success) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            suffix = truthiness == false ? 'failure' : 'success'
            StatsD.increment("#{StatsD::Instrument.generate_metric_name(metric_name, self, *args)}.#{suffix}", 1, *metric_options)
          end
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # Only for successful calls, the metric will be icnremented
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield (see #statsd_count_success)
    # @yieldparam result (see #statsd_count_success)
    # @yieldreturn (see #statsd_count_success)
    # @return [void]
    # @see #statsd_count_success
    def statsd_count_if(method, name, *metric_options)
      add_to_method(method, name, :count_if) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), *metric_options) if truthiness
          end
        end
      end
    end

    # Adds counter instrumentation to a method.
    #
    # The metric will be incremented for every call of the instrumented method, no matter
    # whether what the method returns, or whether it raises an exception.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @return [void]
    def statsd_count(method, name, *metric_options)
      add_to_method(method, name, :count) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), 1, *metric_options)
          send(old_method, *args, &block)
        end
      end
    end

    # Removes StatsD counter instrumentation from a method
    # @param method [Symbol] The method to remove instrumentation from.
    # @param name [String] The name of the metric that was used.
    # @return [void]
    # @see #statsd_count
    def statsd_remove_count(method, name)
      remove_from_method(method, name, :count)
    end

    # Removes StatsD conditional counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_if
    def statsd_remove_count_if(method, name)
      remove_from_method(method, name, :count_if)
    end

    # Removes StatsD success counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_success
    def statsd_remove_count_success(method, name)
      remove_from_method(method, name, :count_success)
    end

    # Removes StatsD measure instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_measure
    def statsd_remove_measure(method, name)
      remove_from_method(method, name, :measure)
    end

    private

    def add_to_method(method, name, action, &block)
      metric_name = name

      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_without_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_with_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      raise ArgumentError, "already instrumented #{method} for #{self.name}" if method_defined? method_name_without_statsd
      raise ArgumentError, "could not find method #{method} for #{self.name}" unless method_defined?(method) || private_method_defined?(method)

      method_scope = method_visibility(method)

      alias_method method_name_without_statsd, method
      yield method_name_without_statsd, method_name_with_statsd, metric_name
      alias_method method, method_name_with_statsd

      private(method_name_without_statsd)
      send(method_scope, method)
      private(method_name_with_statsd)
    end

    def remove_from_method(method, name, action)
      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"

      method_scope = method_visibility(method)

      send(:remove_method, method_name_with_statsd)
      alias_method method, method_name_without_statsd
      send(:remove_method, method_name_without_statsd)

      send(method_scope, method)
    end

    def method_visibility(method)
      case
      when private_method_defined?(method)
        :private
      when protected_method_defined?(method)
        :protected
      else
        :public
      end
    end
  end

  attr_accessor :logger, :default_sample_rate, :prefix
  attr_writer :backend

  def backend
    @backend ||= StatsD::Instrument::Environment.default_backend
  end

  # Emits a duration metric.
  #
  # @overload measure(key, value, metric_options = {})
  #   Emits a measure metric, by providing a duration in milliseconds.
  #   @param key [String] The name of the metric.
  #   @param value [Float] The measured duration in milliseconds
  #   @param metric_options [Hash] Options for the metric
  #   @return [StatsD::Instrument::Metric] The metric that was sent to the backend.
  #
  # @overload measure(key, metric_options = {}, &block)
  #   Emits a measure metric, after measuring the execution duration of the
  #   block passed to this method.
  #   @param key [String] The name of the metric.
  #   @param metric_options [Hash] Options for the metric
  #   @yield The method will yield the block that was passed to this emthod to measure its duration.
  #   @return The value that was returns by the block passed to this method.
  #
  #   @example
  #      http_response = StatsD.measure('HTTP.call.duration') do
  #        HTTP.get(url)
  #      end
  def measure(key, value = nil, *metric_options, &block)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    result = nil
    value  = 1000 * StatsD::Instrument.duration { result = block.call } if block_given?
    metric = collect_metric(hash_argument(metric_options).merge(type: :ms, name: key, value: value))
    result = metric unless block_given?
    result
  end

  # Emits a counter metric.
  # @param key [String] The name of the metric.
  # @param value [Integer] The value to increment the counter by.
  #
  #   You should not compensate for the sample rate using the counter increment. E.g., if
  #   your sample rate is 0.01, you should <b>not</b> use 100 as increment to compensate for it.
  #   The sample rate is part of the packet that is being sent to the server, and the server
  #   should know how to handle it.
  #
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def increment(key, value = 1, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, 1)
    end

    collect_metric(hash_argument(metric_options).merge(type: :c, name: key, value: value))
  end

  # Emits a gauge metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The current value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def gauge(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :g, name: key, value: value))
  end

  # Emits a histogram metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def histogram(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :h, name: key, value: value))
  end

  # Emits a key/value metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the statsite implementation only.
  def key_value(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :kv, name: key, value: value))
  end

  # Emits a set metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def set(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :s, name: key, value: value))
  end

  private

  # Converts old-style ordered arguments in an argument hash for backwards compatibility.
  # @param args [Array] The list of non-required arguments.
  # @return [Hash] The hash of optional arguments.
  def hash_argument(args)
    return {} if args.length == 0
    return args.first if args.length == 1 && args.first.is_a?(Hash)

    order = [:sample_rate, :tags]
    hash = {}
    args.each_with_index do |value, index|
      hash[order[index]] = value
    end

    return hash
  end

  # Instantiates a metric, and sends it to the backend for further processing.
  # @param options (see StatsD::Instrument::Metric#initialize)
  # @return [StatsD::Instrument::Metric] The meric that was sent to the backend.
  def collect_metric(options)
    backend.collect_metric(metric = StatsD::Instrument::Metric.new(options))
    metric
  end
end

#default_sample_rate ⇒ Float

The sample rate to use if the sample rate is unspecified for a metric call.

Returns:

  • (Float) —

    Default is 1.0.



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# File 'lib/statsd/instrument.rb', line 36

module StatsD
  extend self

  # The StatsD::Instrument module provides metaprogramming methods to instrument your methods with
  # StatsD metrics. E.g., yopu can create counters on how often a method is called, how often it is
  # successful, the duration of the methods call, etc.
  module Instrument

    # @private
    def self.generate_metric_name(metric_name, callee, *args)
      metric_name.respond_to?(:call) ? metric_name.call(callee, args).gsub('::', '.') : metric_name.gsub('::', '.')
    end

    if Process.respond_to?(:clock_gettime)
      # @private
      def self.duration
        start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        yield
        Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
      end
    else
      # @private
      def self.duration
        start = Time.now
        yield
        Time.now - start
      end
    end

    # Adds execution duration instrumentation to a method.
    #
    # @param method [Symbol] The name of the method to instrument.
    # @param name [String, #call] The name of the metric to use. You can also pass in a
    #    callable to dynamically generate a metric name
    # @param metric_options (see StatsD#measure)
    # @return [void]
    def statsd_measure(method, name, *metric_options)
      add_to_method(method, name, :measure) do |old_method, new_method, metric_name, *args|
        define_method(new_method) do |*args, &block|
          StatsD.measure(StatsD::Instrument.generate_metric_name(metric_name, self, *args), nil, *metric_options) { send(old_method, *args, &block) }
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # For successful calls, the metric <tt>[name].success</tt> will be incremented; for failed calls, the metric
    # name is <tt>[name].failure</tt>.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield You can pass a block to this method if you want to define yourself what is a successful call
    #   based on the return value of the method.
    # @yieldparam result The return value of the instrumented method.
    # @yieldreturn [Boolean] Return true iff the return value is consisered a success, false otherwise.
    # @return [void]
    # @see #statsd_count_if
    def statsd_count_success(method, name, *metric_options)
      add_to_method(method, name, :count_success) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            suffix = truthiness == false ? 'failure' : 'success'
            StatsD.increment("#{StatsD::Instrument.generate_metric_name(metric_name, self, *args)}.#{suffix}", 1, *metric_options)
          end
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # Only for successful calls, the metric will be icnremented
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield (see #statsd_count_success)
    # @yieldparam result (see #statsd_count_success)
    # @yieldreturn (see #statsd_count_success)
    # @return [void]
    # @see #statsd_count_success
    def statsd_count_if(method, name, *metric_options)
      add_to_method(method, name, :count_if) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), *metric_options) if truthiness
          end
        end
      end
    end

    # Adds counter instrumentation to a method.
    #
    # The metric will be incremented for every call of the instrumented method, no matter
    # whether what the method returns, or whether it raises an exception.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @return [void]
    def statsd_count(method, name, *metric_options)
      add_to_method(method, name, :count) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), 1, *metric_options)
          send(old_method, *args, &block)
        end
      end
    end

    # Removes StatsD counter instrumentation from a method
    # @param method [Symbol] The method to remove instrumentation from.
    # @param name [String] The name of the metric that was used.
    # @return [void]
    # @see #statsd_count
    def statsd_remove_count(method, name)
      remove_from_method(method, name, :count)
    end

    # Removes StatsD conditional counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_if
    def statsd_remove_count_if(method, name)
      remove_from_method(method, name, :count_if)
    end

    # Removes StatsD success counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_success
    def statsd_remove_count_success(method, name)
      remove_from_method(method, name, :count_success)
    end

    # Removes StatsD measure instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_measure
    def statsd_remove_measure(method, name)
      remove_from_method(method, name, :measure)
    end

    private

    def add_to_method(method, name, action, &block)
      metric_name = name

      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_without_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_with_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      raise ArgumentError, "already instrumented #{method} for #{self.name}" if method_defined? method_name_without_statsd
      raise ArgumentError, "could not find method #{method} for #{self.name}" unless method_defined?(method) || private_method_defined?(method)

      method_scope = method_visibility(method)

      alias_method method_name_without_statsd, method
      yield method_name_without_statsd, method_name_with_statsd, metric_name
      alias_method method, method_name_with_statsd

      private(method_name_without_statsd)
      send(method_scope, method)
      private(method_name_with_statsd)
    end

    def remove_from_method(method, name, action)
      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"

      method_scope = method_visibility(method)

      send(:remove_method, method_name_with_statsd)
      alias_method method, method_name_without_statsd
      send(:remove_method, method_name_without_statsd)

      send(method_scope, method)
    end

    def method_visibility(method)
      case
      when private_method_defined?(method)
        :private
      when protected_method_defined?(method)
        :protected
      else
        :public
      end
    end
  end

  attr_accessor :logger, :default_sample_rate, :prefix
  attr_writer :backend

  def backend
    @backend ||= StatsD::Instrument::Environment.default_backend
  end

  # Emits a duration metric.
  #
  # @overload measure(key, value, metric_options = {})
  #   Emits a measure metric, by providing a duration in milliseconds.
  #   @param key [String] The name of the metric.
  #   @param value [Float] The measured duration in milliseconds
  #   @param metric_options [Hash] Options for the metric
  #   @return [StatsD::Instrument::Metric] The metric that was sent to the backend.
  #
  # @overload measure(key, metric_options = {}, &block)
  #   Emits a measure metric, after measuring the execution duration of the
  #   block passed to this method.
  #   @param key [String] The name of the metric.
  #   @param metric_options [Hash] Options for the metric
  #   @yield The method will yield the block that was passed to this emthod to measure its duration.
  #   @return The value that was returns by the block passed to this method.
  #
  #   @example
  #      http_response = StatsD.measure('HTTP.call.duration') do
  #        HTTP.get(url)
  #      end
  def measure(key, value = nil, *metric_options, &block)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    result = nil
    value  = 1000 * StatsD::Instrument.duration { result = block.call } if block_given?
    metric = collect_metric(hash_argument(metric_options).merge(type: :ms, name: key, value: value))
    result = metric unless block_given?
    result
  end

  # Emits a counter metric.
  # @param key [String] The name of the metric.
  # @param value [Integer] The value to increment the counter by.
  #
  #   You should not compensate for the sample rate using the counter increment. E.g., if
  #   your sample rate is 0.01, you should <b>not</b> use 100 as increment to compensate for it.
  #   The sample rate is part of the packet that is being sent to the server, and the server
  #   should know how to handle it.
  #
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def increment(key, value = 1, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, 1)
    end

    collect_metric(hash_argument(metric_options).merge(type: :c, name: key, value: value))
  end

  # Emits a gauge metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The current value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def gauge(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :g, name: key, value: value))
  end

  # Emits a histogram metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def histogram(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :h, name: key, value: value))
  end

  # Emits a key/value metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the statsite implementation only.
  def key_value(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :kv, name: key, value: value))
  end

  # Emits a set metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def set(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :s, name: key, value: value))
  end

  private

  # Converts old-style ordered arguments in an argument hash for backwards compatibility.
  # @param args [Array] The list of non-required arguments.
  # @return [Hash] The hash of optional arguments.
  def hash_argument(args)
    return {} if args.length == 0
    return args.first if args.length == 1 && args.first.is_a?(Hash)

    order = [:sample_rate, :tags]
    hash = {}
    args.each_with_index do |value, index|
      hash[order[index]] = value
    end

    return hash
  end

  # Instantiates a metric, and sends it to the backend for further processing.
  # @param options (see StatsD::Instrument::Metric#initialize)
  # @return [StatsD::Instrument::Metric] The meric that was sent to the backend.
  def collect_metric(options)
    backend.collect_metric(metric = StatsD::Instrument::Metric.new(options))
    metric
  end
end

#logger ⇒ Logger

The logger to use in case of any errors. The logger is also used as default logger for the LoggerBackend (although this can be overwritten).

Returns:

  • (Logger)

See Also:



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# File 'lib/statsd/instrument.rb', line 36

module StatsD
  extend self

  # The StatsD::Instrument module provides metaprogramming methods to instrument your methods with
  # StatsD metrics. E.g., yopu can create counters on how often a method is called, how often it is
  # successful, the duration of the methods call, etc.
  module Instrument

    # @private
    def self.generate_metric_name(metric_name, callee, *args)
      metric_name.respond_to?(:call) ? metric_name.call(callee, args).gsub('::', '.') : metric_name.gsub('::', '.')
    end

    if Process.respond_to?(:clock_gettime)
      # @private
      def self.duration
        start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        yield
        Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
      end
    else
      # @private
      def self.duration
        start = Time.now
        yield
        Time.now - start
      end
    end

    # Adds execution duration instrumentation to a method.
    #
    # @param method [Symbol] The name of the method to instrument.
    # @param name [String, #call] The name of the metric to use. You can also pass in a
    #    callable to dynamically generate a metric name
    # @param metric_options (see StatsD#measure)
    # @return [void]
    def statsd_measure(method, name, *metric_options)
      add_to_method(method, name, :measure) do |old_method, new_method, metric_name, *args|
        define_method(new_method) do |*args, &block|
          StatsD.measure(StatsD::Instrument.generate_metric_name(metric_name, self, *args), nil, *metric_options) { send(old_method, *args, &block) }
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # For successful calls, the metric <tt>[name].success</tt> will be incremented; for failed calls, the metric
    # name is <tt>[name].failure</tt>.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield You can pass a block to this method if you want to define yourself what is a successful call
    #   based on the return value of the method.
    # @yieldparam result The return value of the instrumented method.
    # @yieldreturn [Boolean] Return true iff the return value is consisered a success, false otherwise.
    # @return [void]
    # @see #statsd_count_if
    def statsd_count_success(method, name, *metric_options)
      add_to_method(method, name, :count_success) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            suffix = truthiness == false ? 'failure' : 'success'
            StatsD.increment("#{StatsD::Instrument.generate_metric_name(metric_name, self, *args)}.#{suffix}", 1, *metric_options)
          end
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # Only for successful calls, the metric will be icnremented
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield (see #statsd_count_success)
    # @yieldparam result (see #statsd_count_success)
    # @yieldreturn (see #statsd_count_success)
    # @return [void]
    # @see #statsd_count_success
    def statsd_count_if(method, name, *metric_options)
      add_to_method(method, name, :count_if) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), *metric_options) if truthiness
          end
        end
      end
    end

    # Adds counter instrumentation to a method.
    #
    # The metric will be incremented for every call of the instrumented method, no matter
    # whether what the method returns, or whether it raises an exception.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @return [void]
    def statsd_count(method, name, *metric_options)
      add_to_method(method, name, :count) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), 1, *metric_options)
          send(old_method, *args, &block)
        end
      end
    end

    # Removes StatsD counter instrumentation from a method
    # @param method [Symbol] The method to remove instrumentation from.
    # @param name [String] The name of the metric that was used.
    # @return [void]
    # @see #statsd_count
    def statsd_remove_count(method, name)
      remove_from_method(method, name, :count)
    end

    # Removes StatsD conditional counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_if
    def statsd_remove_count_if(method, name)
      remove_from_method(method, name, :count_if)
    end

    # Removes StatsD success counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_success
    def statsd_remove_count_success(method, name)
      remove_from_method(method, name, :count_success)
    end

    # Removes StatsD measure instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_measure
    def statsd_remove_measure(method, name)
      remove_from_method(method, name, :measure)
    end

    private

    def add_to_method(method, name, action, &block)
      metric_name = name

      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_without_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_with_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      raise ArgumentError, "already instrumented #{method} for #{self.name}" if method_defined? method_name_without_statsd
      raise ArgumentError, "could not find method #{method} for #{self.name}" unless method_defined?(method) || private_method_defined?(method)

      method_scope = method_visibility(method)

      alias_method method_name_without_statsd, method
      yield method_name_without_statsd, method_name_with_statsd, metric_name
      alias_method method, method_name_with_statsd

      private(method_name_without_statsd)
      send(method_scope, method)
      private(method_name_with_statsd)
    end

    def remove_from_method(method, name, action)
      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"

      method_scope = method_visibility(method)

      send(:remove_method, method_name_with_statsd)
      alias_method method, method_name_without_statsd
      send(:remove_method, method_name_without_statsd)

      send(method_scope, method)
    end

    def method_visibility(method)
      case
      when private_method_defined?(method)
        :private
      when protected_method_defined?(method)
        :protected
      else
        :public
      end
    end
  end

  attr_accessor :logger, :default_sample_rate, :prefix
  attr_writer :backend

  def backend
    @backend ||= StatsD::Instrument::Environment.default_backend
  end

  # Emits a duration metric.
  #
  # @overload measure(key, value, metric_options = {})
  #   Emits a measure metric, by providing a duration in milliseconds.
  #   @param key [String] The name of the metric.
  #   @param value [Float] The measured duration in milliseconds
  #   @param metric_options [Hash] Options for the metric
  #   @return [StatsD::Instrument::Metric] The metric that was sent to the backend.
  #
  # @overload measure(key, metric_options = {}, &block)
  #   Emits a measure metric, after measuring the execution duration of the
  #   block passed to this method.
  #   @param key [String] The name of the metric.
  #   @param metric_options [Hash] Options for the metric
  #   @yield The method will yield the block that was passed to this emthod to measure its duration.
  #   @return The value that was returns by the block passed to this method.
  #
  #   @example
  #      http_response = StatsD.measure('HTTP.call.duration') do
  #        HTTP.get(url)
  #      end
  def measure(key, value = nil, *metric_options, &block)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    result = nil
    value  = 1000 * StatsD::Instrument.duration { result = block.call } if block_given?
    metric = collect_metric(hash_argument(metric_options).merge(type: :ms, name: key, value: value))
    result = metric unless block_given?
    result
  end

  # Emits a counter metric.
  # @param key [String] The name of the metric.
  # @param value [Integer] The value to increment the counter by.
  #
  #   You should not compensate for the sample rate using the counter increment. E.g., if
  #   your sample rate is 0.01, you should <b>not</b> use 100 as increment to compensate for it.
  #   The sample rate is part of the packet that is being sent to the server, and the server
  #   should know how to handle it.
  #
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def increment(key, value = 1, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, 1)
    end

    collect_metric(hash_argument(metric_options).merge(type: :c, name: key, value: value))
  end

  # Emits a gauge metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The current value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def gauge(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :g, name: key, value: value))
  end

  # Emits a histogram metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def histogram(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :h, name: key, value: value))
  end

  # Emits a key/value metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the statsite implementation only.
  def key_value(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :kv, name: key, value: value))
  end

  # Emits a set metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def set(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :s, name: key, value: value))
  end

  private

  # Converts old-style ordered arguments in an argument hash for backwards compatibility.
  # @param args [Array] The list of non-required arguments.
  # @return [Hash] The hash of optional arguments.
  def hash_argument(args)
    return {} if args.length == 0
    return args.first if args.length == 1 && args.first.is_a?(Hash)

    order = [:sample_rate, :tags]
    hash = {}
    args.each_with_index do |value, index|
      hash[order[index]] = value
    end

    return hash
  end

  # Instantiates a metric, and sends it to the backend for further processing.
  # @param options (see StatsD::Instrument::Metric#initialize)
  # @return [StatsD::Instrument::Metric] The meric that was sent to the backend.
  def collect_metric(options)
    backend.collect_metric(metric = StatsD::Instrument::Metric.new(options))
    metric
  end
end

#prefix ⇒ String?

The prefix to apply to metric names. This can be useful to group all the metrics for an application in a shared StatsD server.

When using a prefix a dot will be included automatically to separate the prefix from the metric name.

Returns:

  • (String, nil) —

    The prefix, or nil when no prefix is used

See Also:



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# File 'lib/statsd/instrument.rb', line 36

module StatsD
  extend self

  # The StatsD::Instrument module provides metaprogramming methods to instrument your methods with
  # StatsD metrics. E.g., yopu can create counters on how often a method is called, how often it is
  # successful, the duration of the methods call, etc.
  module Instrument

    # @private
    def self.generate_metric_name(metric_name, callee, *args)
      metric_name.respond_to?(:call) ? metric_name.call(callee, args).gsub('::', '.') : metric_name.gsub('::', '.')
    end

    if Process.respond_to?(:clock_gettime)
      # @private
      def self.duration
        start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        yield
        Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
      end
    else
      # @private
      def self.duration
        start = Time.now
        yield
        Time.now - start
      end
    end

    # Adds execution duration instrumentation to a method.
    #
    # @param method [Symbol] The name of the method to instrument.
    # @param name [String, #call] The name of the metric to use. You can also pass in a
    #    callable to dynamically generate a metric name
    # @param metric_options (see StatsD#measure)
    # @return [void]
    def statsd_measure(method, name, *metric_options)
      add_to_method(method, name, :measure) do |old_method, new_method, metric_name, *args|
        define_method(new_method) do |*args, &block|
          StatsD.measure(StatsD::Instrument.generate_metric_name(metric_name, self, *args), nil, *metric_options) { send(old_method, *args, &block) }
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # For successful calls, the metric <tt>[name].success</tt> will be incremented; for failed calls, the metric
    # name is <tt>[name].failure</tt>.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield You can pass a block to this method if you want to define yourself what is a successful call
    #   based on the return value of the method.
    # @yieldparam result The return value of the instrumented method.
    # @yieldreturn [Boolean] Return true iff the return value is consisered a success, false otherwise.
    # @return [void]
    # @see #statsd_count_if
    def statsd_count_success(method, name, *metric_options)
      add_to_method(method, name, :count_success) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            suffix = truthiness == false ? 'failure' : 'success'
            StatsD.increment("#{StatsD::Instrument.generate_metric_name(metric_name, self, *args)}.#{suffix}", 1, *metric_options)
          end
        end
      end
    end

    # Adds success and failure counter instrumentation to a method.
    #
    # A method call will be considered successful if it does not raise an exception, and the result is true-y.
    # Only for successful calls, the metric will be icnremented
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @yield (see #statsd_count_success)
    # @yieldparam result (see #statsd_count_success)
    # @yieldreturn (see #statsd_count_success)
    # @return [void]
    # @see #statsd_count_success
    def statsd_count_if(method, name, *metric_options)
      add_to_method(method, name, :count_if) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          begin
            truthiness = result = send(old_method, *args, &block)
          rescue
            truthiness = false
            raise
          else
            truthiness = (yield(result) rescue false) if block_given?
            result
          ensure
            StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), *metric_options) if truthiness
          end
        end
      end
    end

    # Adds counter instrumentation to a method.
    #
    # The metric will be incremented for every call of the instrumented method, no matter
    # whether what the method returns, or whether it raises an exception.
    #
    # @param method (see #statsd_measure)
    # @param name (see #statsd_measure)
    # @param metric_options (see #statsd_measure)
    # @return [void]
    def statsd_count(method, name, *metric_options)
      add_to_method(method, name, :count) do |old_method, new_method, metric_name|
        define_method(new_method) do |*args, &block|
          StatsD.increment(StatsD::Instrument.generate_metric_name(metric_name, self, *args), 1, *metric_options)
          send(old_method, *args, &block)
        end
      end
    end

    # Removes StatsD counter instrumentation from a method
    # @param method [Symbol] The method to remove instrumentation from.
    # @param name [String] The name of the metric that was used.
    # @return [void]
    # @see #statsd_count
    def statsd_remove_count(method, name)
      remove_from_method(method, name, :count)
    end

    # Removes StatsD conditional counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_if
    def statsd_remove_count_if(method, name)
      remove_from_method(method, name, :count_if)
    end

    # Removes StatsD success counter instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_count_success
    def statsd_remove_count_success(method, name)
      remove_from_method(method, name, :count_success)
    end

    # Removes StatsD measure instrumentation from a method
    # @param method (see #statsd_remove_count)
    # @param name (see #statsd_remove_count)
    # @return [void]
    # @see #statsd_measure
    def statsd_remove_measure(method, name)
      remove_from_method(method, name, :measure)
    end

    private

    def add_to_method(method, name, action, &block)
      metric_name = name

      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_without_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"
      # raw_ssl_request_for_measure_on_FedEx_with_ActiveMerchant.Shipping.#{self.class.name}.ssl_request

      raise ArgumentError, "already instrumented #{method} for #{self.name}" if method_defined? method_name_without_statsd
      raise ArgumentError, "could not find method #{method} for #{self.name}" unless method_defined?(method) || private_method_defined?(method)

      method_scope = method_visibility(method)

      alias_method method_name_without_statsd, method
      yield method_name_without_statsd, method_name_with_statsd, metric_name
      alias_method method, method_name_with_statsd

      private(method_name_without_statsd)
      send(method_scope, method)
      private(method_name_with_statsd)
    end

    def remove_from_method(method, name, action)
      method_name_without_statsd = :"#{method}_for_#{action}_on_#{self.name}_without_#{name}"
      method_name_with_statsd = :"#{method}_for_#{action}_on_#{self.name}_with_#{name}"

      method_scope = method_visibility(method)

      send(:remove_method, method_name_with_statsd)
      alias_method method, method_name_without_statsd
      send(:remove_method, method_name_without_statsd)

      send(method_scope, method)
    end

    def method_visibility(method)
      case
      when private_method_defined?(method)
        :private
      when protected_method_defined?(method)
        :protected
      else
        :public
      end
    end
  end

  attr_accessor :logger, :default_sample_rate, :prefix
  attr_writer :backend

  def backend
    @backend ||= StatsD::Instrument::Environment.default_backend
  end

  # Emits a duration metric.
  #
  # @overload measure(key, value, metric_options = {})
  #   Emits a measure metric, by providing a duration in milliseconds.
  #   @param key [String] The name of the metric.
  #   @param value [Float] The measured duration in milliseconds
  #   @param metric_options [Hash] Options for the metric
  #   @return [StatsD::Instrument::Metric] The metric that was sent to the backend.
  #
  # @overload measure(key, metric_options = {}, &block)
  #   Emits a measure metric, after measuring the execution duration of the
  #   block passed to this method.
  #   @param key [String] The name of the metric.
  #   @param metric_options [Hash] Options for the metric
  #   @yield The method will yield the block that was passed to this emthod to measure its duration.
  #   @return The value that was returns by the block passed to this method.
  #
  #   @example
  #      http_response = StatsD.measure('HTTP.call.duration') do
  #        HTTP.get(url)
  #      end
  def measure(key, value = nil, *metric_options, &block)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    result = nil
    value  = 1000 * StatsD::Instrument.duration { result = block.call } if block_given?
    metric = collect_metric(hash_argument(metric_options).merge(type: :ms, name: key, value: value))
    result = metric unless block_given?
    result
  end

  # Emits a counter metric.
  # @param key [String] The name of the metric.
  # @param value [Integer] The value to increment the counter by.
  #
  #   You should not compensate for the sample rate using the counter increment. E.g., if
  #   your sample rate is 0.01, you should <b>not</b> use 100 as increment to compensate for it.
  #   The sample rate is part of the packet that is being sent to the server, and the server
  #   should know how to handle it.
  #
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def increment(key, value = 1, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, 1)
    end

    collect_metric(hash_argument(metric_options).merge(type: :c, name: key, value: value))
  end

  # Emits a gauge metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The current value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  def gauge(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :g, name: key, value: value))
  end

  # Emits a histogram metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def histogram(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :h, name: key, value: value))
  end

  # Emits a key/value metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the statsite implementation only.
  def key_value(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :kv, name: key, value: value))
  end

  # Emits a set metric.
  # @param key [String] The name of the metric.
  # @param value [Numeric] The value to record.
  # @param metric_options [Hash] (default: {}) Metric options
  # @return (see #collect_metric)
  # @note Supported by the datadog implementation only.
  def set(key, value, *metric_options)
    if value.is_a?(Hash) && metric_options.empty?
      metric_options = [value]
      value = value.fetch(:value, nil)
    end

    collect_metric(hash_argument(metric_options).merge(type: :s, name: key, value: value))
  end

  private

  # Converts old-style ordered arguments in an argument hash for backwards compatibility.
  # @param args [Array] The list of non-required arguments.
  # @return [Hash] The hash of optional arguments.
  def hash_argument(args)
    return {} if args.length == 0
    return args.first if args.length == 1 && args.first.is_a?(Hash)

    order = [:sample_rate, :tags]
    hash = {}
    args.each_with_index do |value, index|
      hash[order[index]] = value
    end

    return hash
  end

  # Instantiates a metric, and sends it to the backend for further processing.
  # @param options (see StatsD::Instrument::Metric#initialize)
  # @return [StatsD::Instrument::Metric] The meric that was sent to the backend.
  def collect_metric(options)
    backend.collect_metric(metric = StatsD::Instrument::Metric.new(options))
    metric
  end
end

Instance Method Details

#gauge(key, value, *metric_options) ⇒ StatsD::Instrument::Metric

Emits a gauge metric.

Parameters:

  • key (String) —

    The name of the metric.

  • value (Numeric) —

    The current value to record.

  • metric_options (Hash) —

    (default: {}) Metric options

Returns:



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# File 'lib/statsd/instrument.rb', line 315

def gauge(key, value, *metric_options)
  if value.is_a?(Hash) && metric_options.empty?
    metric_options = [value]
    value = value.fetch(:value, nil)
  end

  collect_metric(hash_argument(metric_options).merge(type: :g, name: key, value: value))
end

#histogram(key, value, *metric_options) ⇒ StatsD::Instrument::Metric

Note:

Supported by the datadog implementation only.

Emits a histogram metric.

Parameters:

  • key (String) —

    The name of the metric.

  • value (Numeric) —

    The value to record.

  • metric_options (Hash) —

    (default: {}) Metric options

Returns:



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# File 'lib/statsd/instrument.rb', line 330

def histogram(key, value, *metric_options)
  if value.is_a?(Hash) && metric_options.empty?
    metric_options = [value]
    value = value.fetch(:value, nil)
  end

  collect_metric(hash_argument(metric_options).merge(type: :h, name: key, value: value))
end

#increment(key, value = 1, *metric_options) ⇒ StatsD::Instrument::Metric

Emits a counter metric.

Parameters:

  • key (String) —

    The name of the metric.

  • value (Integer) (defaults to: 1) —

    The value to increment the counter by.

    You should not compensate for the sample rate using the counter increment. E.g., if your sample rate is 0.01, you should not use 100 as increment to compensate for it. The sample rate is part of the packet that is being sent to the server, and the server should know how to handle it.

  • metric_options (Hash) —

    (default: {}) Metric options

Returns:



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# File 'lib/statsd/instrument.rb', line 301

def increment(key, value = 1, *metric_options)
  if value.is_a?(Hash) && metric_options.empty?
    metric_options = [value]
    value = value.fetch(:value, 1)
  end

  collect_metric(hash_argument(metric_options).merge(type: :c, name: key, value: value))
end

#key_value(key, value, *metric_options) ⇒ StatsD::Instrument::Metric

Note:

Supported by the statsite implementation only.

Emits a key/value metric.

Parameters:

  • key (String) —

    The name of the metric.

  • value (Numeric) —

    The value to record.

  • metric_options (Hash) —

    (default: {}) Metric options

Returns:



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# File 'lib/statsd/instrument.rb', line 345

def key_value(key, value, *metric_options)
  if value.is_a?(Hash) && metric_options.empty?
    metric_options = [value]
    value = value.fetch(:value, nil)
  end

  collect_metric(hash_argument(metric_options).merge(type: :kv, name: key, value: value))
end

#measure(key, value, metric_options = {}) ⇒ StatsD::Instrument::Metric #measure(key, metric_options = {}) { ... } ⇒ Object

Emits a duration metric.

Overloads:

  • #measure(key, value, metric_options = {}) ⇒ StatsD::Instrument::Metric

    Emits a measure metric, by providing a duration in milliseconds.

    Parameters:

    • key (String) —

      The name of the metric.

    • value (Float) —

      The measured duration in milliseconds

    • metric_options (Hash) (defaults to: {}) —

      Options for the metric

    Returns:

  • #measure(key, metric_options = {}) { ... } ⇒ Object

    Emits a measure metric, after measuring the execution duration of the block passed to this method.

    Examples:

    http_response = StatsD.measure('HTTP.call.duration') do
  HTTP.get(url)
end

    Parameters:

    • key (String) —

      The name of the metric.

    • metric_options (Hash) (defaults to: {}) —

      Options for the metric

    Yields:

    • The method will yield the block that was passed to this emthod to measure its duration.

    Returns:

    • The value that was returns by the block passed to this method.



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# File 'lib/statsd/instrument.rb', line 277

def measure(key, value = nil, *metric_options, &block)
  if value.is_a?(Hash) && metric_options.empty?
    metric_options = [value]
    value = value.fetch(:value, nil)
  end

  result = nil
  value  = 1000 * StatsD::Instrument.duration { result = block.call } if block_given?
  metric = collect_metric(hash_argument(metric_options).merge(type: :ms, name: key, value: value))
  result = metric unless block_given?
  result
end

#set(key, value, *metric_options) ⇒ StatsD::Instrument::Metric

Note:

Supported by the datadog implementation only.

Emits a set metric.

Parameters:

  • key (String) —

    The name of the metric.

  • value (Numeric) —

    The value to record.

  • metric_options (Hash) —

    (default: {}) Metric options

Returns:



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# File 'lib/statsd/instrument.rb', line 360

def set(key, value, *metric_options)
  if value.is_a?(Hash) && metric_options.empty?
    metric_options = [value]
    value = value.fetch(:value, nil)
  end

  collect_metric(hash_argument(metric_options).merge(type: :s, name: key, value: value))
end