debian-mirror-gitlab/lib/gitlab/metrics/delta.rb
2016-01-14 18:37:52 +05:30

32 lines
856 B
Ruby

module Gitlab
module Metrics
# Class for calculating the difference between two numeric values.
#
# Every call to `compared_with` updates the internal value. This makes it
# possible to use a single Delta instance to calculate the delta over time
# of an ever increasing number.
#
# Example usage:
#
# delta = Delta.new(0)
#
# delta.compared_with(10) # => 10
# delta.compared_with(15) # => 5
# delta.compared_with(20) # => 5
class Delta
def initialize(value = 0)
@value = value
end
# new_value - The value to compare with as a Numeric.
#
# Returns a new Numeric (depending on the type of `new_value`).
def compared_with(new_value)
delta = new_value - @value
@value = new_value
delta
end
end
end
end