diff options
Diffstat (limited to 'lib/mongrel/stats.rb')
-rw-r--r-- | lib/mongrel/stats.rb | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/lib/mongrel/stats.rb b/lib/mongrel/stats.rb deleted file mode 100644 index f6cf5ab..0000000 --- a/lib/mongrel/stats.rb +++ /dev/null @@ -1,89 +0,0 @@ -# Copyright (c) 2005 Zed A. Shaw -# You can redistribute it and/or modify it under the same terms as Ruby. -# -# Additional work donated by contributors. See http://mongrel.rubyforge.org/attributions.html -# for more information. - -# A very simple little class for doing some basic fast statistics sampling. -# You feed it either samples of numeric data you want measured or you call -# Stats.tick to get it to add a time delta between the last time you called it. -# When you're done either call sum, sumsq, n, min, max, mean or sd to get -# the information. The other option is to just call dump and see everything. -# -# It does all of this very fast and doesn't take up any memory since the samples -# are not stored but instead all the values are calculated on the fly. -module Mongrel - class Stats - attr_reader :sum, :sumsq, :n, :min, :max - - def initialize(name) - @name = name - reset - end - - # Resets the internal counters so you can start sampling again. - def reset - @sum = 0.0 - @sumsq = 0.0 - @last_time = Time.new - @n = 0.0 - @min = 0.0 - @max = 0.0 - end - - # Adds a sampling to the calculations. - def sample(s) - @sum += s - @sumsq += s * s - if @n == 0 - @min = @max = s - else - @min = s if @min > s - @max = s if @max < s - end - @n+=1 - end - - # Dump this Stats object with an optional additional message. - def dump(msg = "", out=STDERR) - out.puts "#{msg}: #{self.to_s}" - end - - # Returns a common display (used by dump) - def to_s - "[#{@name}]: SUM=%0.4f, SUMSQ=%0.4f, N=%0.4f, MEAN=%0.4f, SD=%0.4f, MIN=%0.4f, MAX=%0.4f" % [@sum, @sumsq, @n, mean, sd, @min, @max] - end - - - # Calculates and returns the mean for the data passed so far. - def mean - @sum / @n - end - - # Calculates the standard deviation of the data so far. - def sd - # (sqrt( ((s).sumsq - ( (s).sum * (s).sum / (s).n)) / ((s).n-1) )) - begin - return Math.sqrt( (@sumsq - ( @sum * @sum / @n)) / (@n-1) ) - rescue Errno::EDOM - return 0.0 - end - end - - - # Adds a time delta between now and the last time you called this. This - # will give you the average time between two activities. - # - # An example is: - # - # t = Stats.new("do_stuff") - # 10000.times { do_stuff(); t.tick } - # t.dump("time") - # - def tick - now = Time.now - sample(now - @last_time) - @last_time = now - end - end -end |