d7b4f36a3c
Process.clock_gettime allows getting the real time in nanoseconds as
well as allowing one to get a monotonic timestamp. This offers greater
accuracy without the overhead of having to allocate a Time instance. In
general using Time.now/Time.new is about 2x slower than using
Process.clock_gettime(). For example:
require 'benchmark/ips'
Benchmark.ips do |bench|
bench.report 'Time.now' do
Time.now.to_f
end
bench.report 'clock_gettime' do
Process.clock_gettime(Process::CLOCK_MONOTONIC, :millisecond)
end
bench.compare!
end
Running this benchmark gives:
Calculating -------------------------------------
Time.now 108.052k i/100ms
clock_gettime 125.984k i/100ms
-------------------------------------------------
Time.now 2.343M (± 7.1%) i/s - 11.670M
clock_gettime 4.979M (± 0.8%) i/s - 24.945M
Comparison:
clock_gettime: 4979393.8 i/s
Time.now: 2342986.8 i/s - 2.13x slower
Another benefit of using Process.clock_gettime() is that we can simplify
the code a bit since it can give timestamps in nanoseconds out of the
box.
52 lines
1.3 KiB
Ruby
52 lines
1.3 KiB
Ruby
module Gitlab
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module Metrics
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# Class for tracking timing information about method calls
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class MethodCall
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attr_reader :real_time, :cpu_time, :call_count
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# name - The full name of the method (including namespace) such as
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# `User#sign_in`.
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#
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# series - The series to use for storing the data.
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def initialize(name, series)
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@name = name
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@series = series
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@real_time = 0.0
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@cpu_time = 0.0
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@call_count = 0
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end
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# Measures the real and CPU execution time of the supplied block.
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def measure
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start_real = System.monotonic_time
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start_cpu = System.cpu_time
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retval = yield
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@real_time += System.monotonic_time - start_real
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@cpu_time += System.cpu_time - start_cpu
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@call_count += 1
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retval
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end
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# Returns a Metric instance of the current method call.
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def to_metric
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Metric.new(
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@series,
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{
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duration: real_time,
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cpu_duration: cpu_time,
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call_count: call_count
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},
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method: @name
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)
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end
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# Returns true if the total runtime of this method exceeds the method call
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# threshold.
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def above_threshold?
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real_time >= Metrics.method_call_threshold
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end
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end
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end
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end
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