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5bb1d4d288
I wrote a utility that helps find areas where you could optimize your program using a frozen string instead of a string literal, it's called [let_it_go](https://github.com/schneems/let_it_go). After going through the output and adding `.freeze` I was able to eliminate the creation of 1,114 string objects on EVERY request to [codetriage](codetriage.com). How does this impact execution? To look at memory: ```ruby require 'get_process_mem' mem = GetProcessMem.new GC.start GC.disable 1_114.times { " " } before = mem.mb after = mem.mb GC.enable puts "Diff: #{after - before} mb" ``` Creating 1,114 string objects results in `Diff: 0.03125 mb` of RAM allocated on every request. Or 1mb every 32 requests. To look at raw speed: ```ruby require 'benchmark/ips' number_of_objects_reduced = 1_114 Benchmark.ips do |x| x.report("freeze") { number_of_objects_reduced.times { " ".freeze } } x.report("no-freeze") { number_of_objects_reduced.times { " " } } end ``` We get the results ``` Calculating ------------------------------------- freeze 1.428k i/100ms no-freeze 609.000 i/100ms ------------------------------------------------- freeze 14.363k (± 8.5%) i/s - 71.400k no-freeze 6.084k (± 8.1%) i/s - 30.450k ``` Now we can do some maths: ```ruby ips = 6_226k # iterations / 1 second call_time_before = 1.0 / ips # seconds per iteration ips = 15_254 # iterations / 1 second call_time_after = 1.0 / ips # seconds per iteration diff = call_time_before - call_time_after number_of_objects_reduced * diff * 100 # => 0.4530373333993266 miliseconds saved per request ``` So we're shaving off 1 second of execution time for every 220 requests. Is this going to be an insane speed boost to any Rails app: nope. Should we merge it: yep. p.s. If you know of a method call that doesn't modify a string input such as [String#gsub](b0e2da69f0/lib/let_it_go/core_ext/string.rb (L37)) please [give me a pull request to the appropriate file](b0e2da69f0/lib/let_it_go/core_ext/string.rb (L37)), or open an issue in LetItGo so we can track and freeze more strings. Keep those strings Frozen 
74 lines
2.4 KiB
Ruby
74 lines
2.4 KiB
Ruby
module ActionController
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class LogSubscriber < ActiveSupport::LogSubscriber
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INTERNAL_PARAMS = %w(controller action format _method only_path)
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def start_processing(event)
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return unless logger.info?
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payload = event.payload
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params = payload[:params].except(*INTERNAL_PARAMS)
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format = payload[:format]
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format = format.to_s.upcase if format.is_a?(Symbol)
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info "Processing by #{payload[:controller]}##{payload[:action]} as #{format}"
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info " Parameters: #{params.inspect}" unless params.empty?
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end
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def process_action(event)
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info do
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payload = event.payload
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additions = ActionController::Base.log_process_action(payload)
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status = payload[:status]
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if status.nil? && payload[:exception].present?
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exception_class_name = payload[:exception].first
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status = ActionDispatch::ExceptionWrapper.status_code_for_exception(exception_class_name)
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end
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message = "Completed #{status} #{Rack::Utils::HTTP_STATUS_CODES[status]} in #{event.duration.round}ms"
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message << " (#{additions.join(" | ".freeze)})" unless additions.blank?
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message
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end
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end
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def halted_callback(event)
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info { "Filter chain halted as #{event.payload[:filter].inspect} rendered or redirected" }
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end
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def send_file(event)
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info { "Sent file #{event.payload[:path]} (#{event.duration.round(1)}ms)" }
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end
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def redirect_to(event)
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info { "Redirected to #{event.payload[:location]}" }
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end
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def send_data(event)
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info { "Sent data #{event.payload[:filename]} (#{event.duration.round(1)}ms)" }
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end
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def unpermitted_parameters(event)
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debug do
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unpermitted_keys = event.payload[:keys]
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"Unpermitted parameter#{'s' if unpermitted_keys.size > 1}: #{unpermitted_keys.join(", ")}"
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end
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end
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%w(write_fragment read_fragment exist_fragment?
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expire_fragment expire_page write_page).each do |method|
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class_eval <<-METHOD, __FILE__, __LINE__ + 1
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def #{method}(event)
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return unless logger.info?
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key_or_path = event.payload[:key] || event.payload[:path]
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human_name = #{method.to_s.humanize.inspect}
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info("\#{human_name} \#{key_or_path} (\#{event.duration.round(1)}ms)")
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end
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METHOD
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end
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def logger
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ActionController::Base.logger
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end
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end
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end
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ActionController::LogSubscriber.attach_to :action_controller
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