1 #!/usr/bin/env ruby 2 3 # Copyright 2016 gRPC authors. 4 # 5 # Licensed under the Apache License, Version 2.0 (the "License"); 6 # you may not use this file except in compliance with the License. 7 # You may obtain a copy of the License at 8 # 9 # http://www.apache.org/licenses/LICENSE-2.0 10 # 11 # Unless required by applicable law or agreed to in writing, software 12 # distributed under the License is distributed on an "AS IS" BASIS, 13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 # See the License for the specific language governing permissions and 15 # limitations under the License. 16 17 # Histogram class for use in performance testing and measurement 18 19 require 'thread' 20 21 class Histogram 22 # Determine the bucket index for a given value 23 # @param {number} value The value to check 24 # @return {number} The bucket index 25 def bucket_for(value) 26 (Math.log(value)/Math.log(@multiplier)).to_i 27 end 28 # Initialize an empty histogram 29 # @param {number} resolution The resolution of the histogram 30 # @param {number} max_possible The maximum value for the histogram 31 def initialize(resolution, max_possible) 32 @lock = Mutex.new 33 @resolution=resolution 34 @max_possible=max_possible 35 @sum=0 36 @sum_of_squares=0 37 @multiplier=1+resolution 38 @count=0 39 @min_seen=max_possible 40 @max_seen=0 41 @buckets=Array.new(bucket_for(max_possible)+1, 0) 42 end 43 # Add a value to the histogram. This updates all statistics with the new 44 # value. Those statistics should not be modified except with this function 45 # @param {number} value The value to add 46 def add(value) 47 @sum += value 48 @sum_of_squares += value * value 49 @count += 1 50 if value < @min_seen 51 @min_seen = value 52 end 53 if value > @max_seen 54 @max_seen = value 55 end 56 @buckets[bucket_for(value)] += 1 57 end 58 def minimum 59 @min_seen 60 end 61 def maximum 62 @max_seen 63 end 64 def sum 65 @sum 66 end 67 def sum_of_squares 68 @sum_of_squares 69 end 70 def count 71 @count 72 end 73 def contents 74 @buckets 75 end 76 77 def merge(hist) 78 @lock.synchronize do 79 @min_seen = hist.min_seen 80 @max_seen = hist.max_seen 81 @sum += hist.sum 82 @sum_of_squares += hist.sum_of_squares 83 @count += hist.count 84 received_bucket = hist.bucket.to_a 85 @buckets = @buckets.map.with_index{ |m,i| m + received_bucket[i].to_i } 86 end 87 end 88 end 89
