blob: e48fb842be4c8843140f08edc8fc2cb5b2b6066f [file] [log] [blame]
#!/usr/bin/env ruby
# Copyright 2016 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Histogram class for use in performance testing and measurement
require 'thread'
class Histogram
# Determine the bucket index for a given value
# @param {number} value The value to check
# @return {number} The bucket index
def bucket_for(value)
(Math.log(value)/Math.log(@multiplier)).to_i
end
# Initialize an empty histogram
# @param {number} resolution The resolution of the histogram
# @param {number} max_possible The maximum value for the histogram
def initialize(resolution, max_possible)
@lock = Mutex.new
@resolution=resolution
@max_possible=max_possible
@sum=0
@sum_of_squares=0
@multiplier=1+resolution
@count=0
@min_seen=max_possible
@max_seen=0
@buckets=Array.new(bucket_for(max_possible)+1, 0)
end
# Add a value to the histogram. This updates all statistics with the new
# value. Those statistics should not be modified except with this function
# @param {number} value The value to add
def add(value)
@sum += value
@sum_of_squares += value * value
@count += 1
if value < @min_seen
@min_seen = value
end
if value > @max_seen
@max_seen = value
end
@buckets[bucket_for(value)] += 1
end
def minimum
@min_seen
end
def maximum
@max_seen
end
def sum
@sum
end
def sum_of_squares
@sum_of_squares
end
def count
@count
end
def contents
@buckets
end
def merge(hist)
@lock.synchronize do
@min_seen = hist.min_seen
@max_seen = hist.max_seen
@sum += hist.sum
@sum_of_squares += hist.sum_of_squares
@count += hist.count
received_bucket = hist.bucket.to_a
@buckets = @buckets.map.with_index{ |m,i| m + received_bucket[i].to_i }
end
end
end