meter.rb in ruby-metrics-0.9.4

- old
+ new

@@ -5,61 +5,58 @@
   module Instruments
     class Meter < Instrument
       include Metrics::TimeConversion
 
       # From http://www.teamquest.com/pdfs/whitepaper/ldavg2.pdf
-      INTERVAL = 5.0
-      INTERVAL_IN_NS = 5000000000.0
-      ONE_MINUTE_FACTOR     = 1 - Math.exp(-INTERVAL / 60.0)
-      FIVE_MINUTE_FACTOR    = 1 - Math.exp(-INTERVAL / (60.0 * 5.0))
-      FIFTEEN_MINUTE_FACTOR = 1 - Math.exp(-INTERVAL / (60.0 * 15.0))
+      INTERVAL_SECONDS = 5.0
+      ONE_MINUTE_FACTOR     = 1 - Math.exp(-INTERVAL_SECONDS / 60.0)
+      FIVE_MINUTE_FACTOR    = 1 - Math.exp(-INTERVAL_SECONDS / (60.0 * 5.0))
+      FIFTEEN_MINUTE_FACTOR = 1 - Math.exp(-INTERVAL_SECONDS / (60.0 * 15.0))
 
-      attr_reader :count
-      attr_reader :units
+      attr_reader :count, :units
       alias_method :counted, :count
 
       def initialize(options = {})
-        @one_minute_rate = @five_minute_rate = @fifteen_minute_rate = 0.0
-        @count  = 0
-        @initialized = false
-        @start_time = Time.now.to_f
         @units = options[:units]
+        clear
 
         @timer_thread = Thread.new do
           begin
             loop do
-              self.tick
-              sleep(INTERVAL)
+              tick
+              sleep(INTERVAL_SECONDS)
             end
           rescue Exception => e
             logger.error "Error in timer thread: #{e.class.name}: #{e}\n  #{e.backtrace.join("\n  ")}"
-          end # begin
-        end # thread new
-
+          end
+        end
       end
 
       def clear
+        @one_minute_rate = @five_minute_rate = @fifteen_minute_rate = 0.0
+        @count  = 0
+        @initialized = false
+        @start_time = Time.now.to_f
       end
 
       def mark(count = 1)
         @count += count
       end
 
       def calc_rate(rate, factor, count)
-        rate = rate.to_f + (factor.to_f * (count.to_f - rate.to_f))
-        rate.to_f
+        rate.to_f + factor.to_f * (count.to_f - rate.to_f)
       end
 
       def tick
-        count = @count.to_f  / Seconds.to_nsec(INTERVAL).to_f
+        count = @count.to_f / Seconds.to_nsec(INTERVAL_SECONDS).to_f
 
-        if (@initialized)
+        if @initialized
           @one_minute_rate      = calc_rate(@one_minute_rate,     ONE_MINUTE_FACTOR,     count)
           @five_minute_rate     = calc_rate(@five_minute_rate,    FIVE_MINUTE_FACTOR,    count)
           @fifteen_minute_rate  = calc_rate(@fifteen_minute_rate, FIFTEEN_MINUTE_FACTOR, count)
         else
-          @one_minute_rate = @five_minute_rate = @fifteen_minute_rate  = (count)
+          @one_minute_rate = @five_minute_rate = @fifteen_minute_rate  = count
           @initialized = true
         end
 
         @count = 0
       end
@@ -75,24 +72,23 @@
       def fifteen_minute_rate(rate_unit = :seconds)
         convert_to_ns @fifteen_minute_rate, rate_unit
       end
 
       def mean_rate(rate_unit = :seconds)
-        count = @count
-        if count == 0
-          return 0.0
+        if @count == 0
+          0.0
         else
           elapsed = Time.now.to_f - @start_time.to_f
-          mult = scale_time_units(:seconds, rate_unit)
-          count.to_f / (mult * elapsed.to_f)
+          scale_factor = scale_time_units(:seconds, rate_unit)
+          @count.to_f / (elapsed * scale_factor)
         end
       end
 
       def as_json(*_)
         {
-          :one_minute_rate => self.one_minute_rate,
-          :five_minute_rate => self.five_minute_rate,
-          :fifteen_minute_rate => self.fifteen_minute_rate
+          :one_minute_rate      => one_minute_rate,
+          :five_minute_rate     => five_minute_rate,
+          :fifteen_minute_rate  => fifteen_minute_rate
         }
       end
 
       def to_json(*_)
         as_json.to_json