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Diffstat (limited to 'guides/source/contributing_to_ruby_on_rails.md')
| -rw-r--r-- | guides/source/contributing_to_ruby_on_rails.md | 45 |
1 files changed, 18 insertions, 27 deletions
diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md index 4f938f5deb..830a546570 100644 --- a/guides/source/contributing_to_ruby_on_rails.md +++ b/guides/source/contributing_to_ruby_on_rails.md @@ -270,33 +270,24 @@ The above are guidelines - please use your best judgment in using them. ### Benchmark Your Code -If your change has an impact on the performance of Rails, please use the -[benchmark-ips](https://github.com/evanphx/benchmark-ips) gem to provide -benchmark results for comparison. - -Here's an example of using benchmark-ips: - -```ruby -require 'benchmark/ips' - -Benchmark.ips do |x| - x.report('addition') { 1 + 2 } - x.report('addition with send') { 1.send(:+, 2) } -end -``` - -This will generate a report with the following information: - -``` -Calculating ------------------------------------- - addition 132.013k i/100ms - addition with send 125.413k i/100ms -------------------------------------------------- - addition 9.677M (± 1.7%) i/s - 48.449M - addition with send 6.794M (± 1.1%) i/s - 33.987M -``` - -Please see the benchmark/ips [README](https://github.com/evanphx/benchmark-ips/blob/master/README.md) for more information. +For changes that might have an impact on performance, please benchmark your +code and measure the impact. Please share the benchmark script you used as well +as the results. You should consider including this information in your commit +message, which allows future contributors to easily verify your findings and +determine if they are still relevant. (For example, future optimizations in the +Ruby VM might render certain optimizations unnecessary.) + +It is very easy to make an optimization that improves performance for a +specific scenario you care about but regresses on other common cases. +Therefore, you should test your change against a list of representative +scenarios. Ideally, they should be based on real-world scenarios extracted +from production applications. + +You can use the [benchmark template](https://github.com/rails/rails/blob/master/guides/bug_report_templates/benchmark.rb) +as a starting point. It includes the boilerplate code to setup a benchmark +using the [benchmark-ips](https://github.com/evanphx/benchmark-ips) gem. The +template is designed for testing relatively self-contained changes that can be +inlined into the script. ### Running Tests |