Since I'm doing some time measurements at the moment, I wondered if it is possible to measure the user time or system time without using the Benchmark
class or the command line utility time
.
Using the Time
class only reveals the wall clock time, not system and user time, however I'm looking for a solution which has the same flexibility, e.g.
time = TimeUtility.now
# some code
user, system, real = TimeUtility.now - time
The reason is that I somehow dislike Benchmark
, since it cannot return numbers only (EDIT: I was wrong - it can. See answers below.). Sure, I could parse the output, but that doesn't feels right. The time
utility from *NIX systems should solve my problem as well, but I wanted to know if there already is some kind of wrapper implemented in Ruby so I don't need to make these system calls by myself.
Thanks a lot!
I re-read the Benchmark documentation and saw that it has a method named measure
. This method does exactly what I want: Measure the time your code needs and returning an object which contains user time, system time, system time of childrens etc. It is as easy as
require 'benchmark'
measurement = Benchmark.measure do
# your code goes here
end
In the process I found out that you can add custom rows to the Benchmark output. You can use this to get the best of both worlds (custom time measurements and a nice output at the end) as follows:
require 'benchmark'
measurements = []
10.times { measurements << Benchmark.measure { 1_000_000.times { a = "1" } } }
# measurements.sum or measurements.inject(0){...} does not work, since the
# array contains Benchmark instances, which cannot be coerced into Fixnum's
# Array#sum will work if you are using Rails
sum = measurements.inject(nil) { |sum, t| sum.nil? ? sum = t : sum += t }
avg = sum / measurements.size
# 7 is the width reserved for the description "sum:" and "avg:"
Benchmark.bm(7, "sum:", "avg:") do |b|
[sum, avg]
end
The result will look like the following:
user system total real
sum: 2.700000 0.000000 2.700000 ( 2.706234)
avg: 0.270000 0.000000 0.270000 ( 0.270623)