From 5bb1d4d288d019e276335465d0389fd2f5246bfd Mon Sep 17 00:00:00 2001 From: schneems Date: Sun, 19 Jul 2015 16:19:15 -0500 Subject: Freeze string literals when not mutated. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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](https://github.com/schneems/let_it_go/blob/b0e2da69f0cca87ab581022baa43291cdf48638c/lib/let_it_go/core_ext/string.rb#L37) please [give me a pull request to the appropriate file](https://github.com/schneems/let_it_go/blob/b0e2da69f0cca87ab581022baa43291cdf48638c/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 ![](https://www.dropbox.com/s/z4dj9fdsv213r4v/let-it-go.gif?dl=1) --- actionpack/lib/abstract_controller/base.rb | 2 +- actionpack/lib/abstract_controller/helpers.rb | 2 +- actionpack/lib/action_controller/log_subscriber.rb | 2 +- actionpack/lib/action_controller/metal/helpers.rb | 4 ++-- actionpack/lib/action_dispatch/http/parameter_filter.rb | 8 ++++---- actionpack/lib/action_dispatch/http/url.rb | 2 +- actionpack/lib/action_dispatch/journey/nodes/node.rb | 2 +- actionpack/lib/action_dispatch/journey/router/utils.rb | 6 +++--- actionpack/lib/action_dispatch/middleware/static.rb | 6 +++--- actionpack/lib/action_dispatch/routing/route_set.rb | 2 +- 10 files changed, 18 insertions(+), 18 deletions(-) (limited to 'actionpack/lib') diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb index ebd02bd9a1..784092867c 100644 --- a/actionpack/lib/abstract_controller/base.rb +++ b/actionpack/lib/abstract_controller/base.rb @@ -96,7 +96,7 @@ module AbstractController # ==== Returns # * String def controller_path - @controller_path ||= name.sub(/Controller$/, '').underscore unless anonymous? + @controller_path ||= name.sub(/Controller$/, ''.freeze).underscore unless anonymous? end # Refresh the cached action_methods when a new action_method is added. diff --git a/actionpack/lib/abstract_controller/helpers.rb b/actionpack/lib/abstract_controller/helpers.rb index 109eff10eb..d84c238a62 100644 --- a/actionpack/lib/abstract_controller/helpers.rb +++ b/actionpack/lib/abstract_controller/helpers.rb @@ -181,7 +181,7 @@ module AbstractController end def default_helper_module! - module_name = name.sub(/Controller$/, '') + module_name = name.sub(/Controller$/, ''.freeze) module_path = module_name.underscore helper module_path rescue LoadError => e diff --git a/actionpack/lib/action_controller/log_subscriber.rb b/actionpack/lib/action_controller/log_subscriber.rb index 87609d8aa7..4c9f14e409 100644 --- a/actionpack/lib/action_controller/log_subscriber.rb +++ b/actionpack/lib/action_controller/log_subscriber.rb @@ -25,7 +25,7 @@ module ActionController status = ActionDispatch::ExceptionWrapper.status_code_for_exception(exception_class_name) end message = "Completed #{status} #{Rack::Utils::HTTP_STATUS_CODES[status]} in #{event.duration.round}ms" - message << " (#{additions.join(" | ")})" unless additions.blank? + message << " (#{additions.join(" | ".freeze)})" unless additions.blank? message end end diff --git a/actionpack/lib/action_controller/metal/helpers.rb b/actionpack/lib/action_controller/metal/helpers.rb index b4da381d26..fcaf3e6425 100644 --- a/actionpack/lib/action_controller/metal/helpers.rb +++ b/actionpack/lib/action_controller/metal/helpers.rb @@ -73,7 +73,7 @@ module ActionController # Provides a proxy to access helpers methods from outside the view. def helpers - @helper_proxy ||= begin + @helper_proxy ||= begin proxy = ActionView::Base.new proxy.config = config.inheritable_copy proxy.extend(_helpers) @@ -100,7 +100,7 @@ module ActionController def all_helpers_from_path(path) helpers = Array(path).flat_map do |_path| extract = /^#{Regexp.quote(_path.to_s)}\/?(.*)_helper.rb$/ - names = Dir["#{_path}/**/*_helper.rb"].map { |file| file.sub(extract, '\1') } + names = Dir["#{_path}/**/*_helper.rb"].map { |file| file.sub(extract, '\1'.freeze) } names.sort! end helpers.uniq! diff --git a/actionpack/lib/action_dispatch/http/parameter_filter.rb b/actionpack/lib/action_dispatch/http/parameter_filter.rb index 6e058b829e..e826551f4b 100644 --- a/actionpack/lib/action_dispatch/http/parameter_filter.rb +++ b/actionpack/lib/action_dispatch/http/parameter_filter.rb @@ -34,11 +34,11 @@ module ActionDispatch end end - deep_regexps, regexps = regexps.partition { |r| r.to_s.include?("\\.") } - deep_strings, strings = strings.partition { |s| s.include?("\\.") } + deep_regexps, regexps = regexps.partition { |r| r.to_s.include?("\\.".freeze) } + deep_strings, strings = strings.partition { |s| s.include?("\\.".freeze) } - regexps << Regexp.new(strings.join('|'), true) unless strings.empty? - deep_regexps << Regexp.new(deep_strings.join('|'), true) unless deep_strings.empty? + regexps << Regexp.new(strings.join('|'.freeze), true) unless strings.empty? + deep_regexps << Regexp.new(deep_strings.join('|'.freeze), true) unless deep_strings.empty? new regexps, deep_regexps, blocks end diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb index f5b709ccd6..6fcf49030b 100644 --- a/actionpack/lib/action_dispatch/http/url.rb +++ b/actionpack/lib/action_dispatch/http/url.rb @@ -245,7 +245,7 @@ module ActionDispatch # req = Request.new 'HTTP_HOST' => 'example.com:8080' # req.host # => "example.com" def host - raw_host_with_port.sub(/:\d+$/, '') + raw_host_with_port.sub(/:\d+$/, ''.freeze) end # Returns a \host:\port string for this request, such as "example.com" or diff --git a/actionpack/lib/action_dispatch/journey/nodes/node.rb b/actionpack/lib/action_dispatch/journey/nodes/node.rb index bb01c087bc..cf6542b370 100644 --- a/actionpack/lib/action_dispatch/journey/nodes/node.rb +++ b/actionpack/lib/action_dispatch/journey/nodes/node.rb @@ -30,7 +30,7 @@ module ActionDispatch end def name - left.tr '*:', '' + left.tr '*:'.freeze, ''.freeze end def type diff --git a/actionpack/lib/action_dispatch/journey/router/utils.rb b/actionpack/lib/action_dispatch/journey/router/utils.rb index d02ed96d0d..9793ca1c7a 100644 --- a/actionpack/lib/action_dispatch/journey/router/utils.rb +++ b/actionpack/lib/action_dispatch/journey/router/utils.rb @@ -14,10 +14,10 @@ module ActionDispatch # normalize_path("/%ab") # => "/%AB" def self.normalize_path(path) path = "/#{path}" - path.squeeze!('/') - path.sub!(%r{/+\Z}, '') + path.squeeze!('/'.freeze) + path.sub!(%r{/+\Z}, ''.freeze) path.gsub!(/(%[a-f0-9]{2})/) { $1.upcase } - path = '/' if path == '' + path = '/' if path == ''.freeze path end diff --git a/actionpack/lib/action_dispatch/middleware/static.rb b/actionpack/lib/action_dispatch/middleware/static.rb index b098ea389f..f38da4fdf6 100644 --- a/actionpack/lib/action_dispatch/middleware/static.rb +++ b/actionpack/lib/action_dispatch/middleware/static.rb @@ -35,7 +35,7 @@ module ActionDispatch paths = [path, "#{path}#{ext}", "#{path}/#{@index}#{ext}"] if match = paths.detect { |p| - path = File.join(@root, p.force_encoding('UTF-8')) + path = File.join(@root, p.force_encoding('UTF-8'.freeze)) begin File.file?(path) && File.readable?(path) rescue SystemCallError @@ -76,7 +76,7 @@ module ActionDispatch end def content_type(path) - ::Rack::Mime.mime_type(::File.extname(path), 'text/plain') + ::Rack::Mime.mime_type(::File.extname(path), 'text/plain'.freeze) end def gzip_encoding_accepted?(env) @@ -112,7 +112,7 @@ module ActionDispatch def call(env) case env['REQUEST_METHOD'] when 'GET', 'HEAD' - path = env['PATH_INFO'].chomp('/') + path = env['PATH_INFO'].chomp('/'.freeze) if match = @file_handler.match?(path) env['PATH_INFO'] = match return @file_handler.call(env) diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb index 454593b59f..42512cad91 100644 --- a/actionpack/lib/action_dispatch/routing/route_set.rb +++ b/actionpack/lib/action_dispatch/routing/route_set.rb @@ -671,7 +671,7 @@ module ActionDispatch # Remove leading slashes from controllers def normalize_controller! - @options[:controller] = controller.sub(%r{^/}, '') if controller + @options[:controller] = controller.sub(%r{^/}, ''.freeze) if controller end # Move 'index' action from options to recall -- cgit v1.2.3