JezK
Edit File: timed_metric.rb
#-- # Copyright (c) 2008, 2009 Jeremy Hinegardner # All rights reserved. See LICENSE and/or COPYING for details. #++ require 'forwardable' module Hitimes # # A TimedMetric holds the metrics on how long it takes to do something. For # example, measuring how long a method takes to operate. # # tm = TimedMetric.new( 'my-method' ) # # 200.times do # my_method_result = tm.measure do # my_method( ... ) # end # end # # puts "#{ tm.name } operated at a rate of #{ tm.rate } calls per second" # # Since TimedMetric is a child class of Metric make sure to look at the # Metric API also. # # A TimedMetric measures the execution time of an option with the Interval # class. # # A TimedMetric contains a Stats object, therefore TimedMetric has +count+, +max+, # +mean+, +min+, +rate+, +stddev+, +sum+, +sumsq+ methods that delegate to that Stats # object for convenience. # # class TimedMetric < Metric # holds all the statistics attr_reader :stats class << TimedMetric # # :call-seq: # TimedMetric.now -> TimedMetric # # Return a TimedMetric that has been started # def now( name, additional_data = {} ) t = TimedMetric.new( name, additional_data ) t.start return t end end # # :call-seq: # TimedMetric.new( 'name') -> TimedMetric # TimedMetric.new( 'name', 'other' => 'data') -> TimedMetric # # Create a new TimedMetric giving it a name and additional data. # +additional_data+ may be anything that follows the +to_hash+ protocol # def initialize( name, additional_data = {} ) super( name, additional_data ) @stats = Stats.new @current_interval = Interval.new end # # :call-seq: # timed_metric.running? -> true or false # # return whether or not the timer is currently running. # def running? @current_interval.running? end # # :call-seq: # timed_metric.start -> nil # # Start the current metric, if the current metric is already started, then # this is a noop. # def start if not @current_interval.running? then @current_interval.start @sampling_start_time ||= self.utc_microseconds() @sampling_start_interval ||= Interval.now end nil end # # :call-seq: # timed_metric.stop -> Float or nil # # Stop the current metric. This updates the stats and removes the current # interval. If the timer was stopped then the duration of the last Interval # is returned. If the timer was already stopped then false is returned and # no stats are updated. # def stop if @current_interval.running? then d = @current_interval.stop @stats.update( d ) @current_interval = Interval.new # update the length of time we have been sampling @sampling_delta = @sampling_start_interval.duration_so_far return d end return false end # # :call-seq: # timed_metric.measure { ... } -> Object # # Measure the execution of a block and add those stats to the running stats. # The return value is the return value of the block # def measure( &block ) return_value = nil begin start return_value = yield ensure stop end return return_value end # # :call-seq: # timed_metric.split -> Float # # Split the current TimedMetric. Essentially, mark a split time. This means # stop the current interval and create a new interval, but make sure # that the new interval lines up exactly, timewise, behind the previous # interval. # # If the timer is running, then split returns the duration of the previous # interval, i.e. the split-time. If the timer is not running, nothing # happens and false is returned. # def split if @current_interval.running? then next_interval = @current_interval.split d = @current_interval.duration @stats.update( d ) @current_interval = next_interval return d end return false end # # :call-seq: # metric.to_hash -> Hash # # Convert the metric to a hash # def to_hash h = super Stats::STATS.each do |s| h[s] = self.send( s ) end return h end # forward appropriate calls directly to the stats object extend Forwardable def_delegators :@stats, :count, :max, :mean, :min, :rate, :stddev, :sum, :sumsq alias :duration :sum end end