Performance sucker! -> Get performance doubled!

[janbiedermann]

sprockets-3.7.1/lib/sprockets/uri_utils.rb
in
def split_file_uri(uri)

Line 51

      # Hack for parsing Windows "file:///C:/Users/IEUser" paths
      path.gsub!(/^\/([a-zA-Z]:)/, '\1'.freeze)

is a performance sucker. Replacing it with this:

      # Hack for parsing Windows "file:///C:/Users/IEUser" paths
      path.gsub!(/^\/([a-zA-Z]:)/, '\1'.freeze) if path[9].include?(':')

DOUBLES performance for me, that is injavascript_include_tag 'applications.js', generating the <script> tag, time going down from 3 seconds to 1.5 seconds, in rails, development environment, with opal-rails and ruby-hyperloop.org.

[schneems]

Send me a PR?

[janbiedermann]

Ok, a little later, currently busy investigating another, maybe related issue

[schneems]

Also strings can start with file:/// or file://

[janbiedermann]

yes, i am looking for file:///c:, the second :, because its about windows, and i don't use windows,
and the regexp does so too, its looking for /c:, if i understand it correctly, if it runs on windows, in [9] will be a :, if it doesn't, no need to gsub

[janbiedermann]

Note to self: Try with this:

require 'rbconfig'
@platform = case RbConfig::CONFIG['host_os']
           when /darwin/
              OSX
           when /win/
              WINDOWS
end`

thanks to @fkchang

[schneems]

I'm saying that while doing the check we have to check for a colon in both index path[9] and path[8] since the start of the string could have 2 slashes or 3.

Also we can use a straight equal == instead of include?(':') as it will do less work and be faster.

[schneems]

We generally use File::ALT_SEPARATOR to detect windows

sprockets/lib/sprockets/path_utils.rb

Line 76 in 341fed4

if File::ALT_SEPARATOR

[janbiedermann]

Oh, yes, before i had

if path[7..9].include?(':')

thats where the include came from, then i thought [7..8] is not legal and changed it to [9]

[janbiedermann]

Great, then File::ALT_SEPARATOR it shall be

[ahorek]

hi, the comment is misleading. 'path' variable contains already parsed uri, so it actualy looks like this

# Hack for parsing Windows "/C:/Users/IEUser" paths
if File::ALT_SEPARATOR
  path = path[1..-1]
end

[janbiedermann]

patches and numbers
#506
sorry, forgot about path[1..-1]

[janbiedermann]

Here are numbers, effects per patch vs. stock 3.7.1 for a large set of assets like in opal-rails/ruby-hyperloop on my machine, large rails app, time taken for a javascript_include_tag, development environment, ruby-2.4.2, macOS, assets.debug = true, FileStore, best out of 10:

without compile

3.7.1 stock:         5.08s
3.7.1 3.x perf #506: 2.51s, ~2x
3.7.1 cache:         3.67s, ~1.38x
3.7.1 regexp:        3.85s, ~1.31x

conclusion

regexp patch and cache size patch are most effective, performance doubled
digest, fqmatch, fastcomp each give mixed results, non conclusive

opal recompiling an *.rb

3.7.1 stock:          7.08s
3.7.1 3.x perf #506:  3.09s, ~2.2x
3.7.1 cache:          5.38s, ~1.31x
3.7.1 regexp:         5.07s, ~1.38x

conclusion

regexp patch and cache size patch are most effective, performance doubled
digest, fqmatch, fastcomp each give mixed results, non conclusive

[janbiedermann]

without compile

3.7.1 3.x perf proper #509: 2.66s, ~1.9x

opal recompiling an *.rb

3.7.1 3.x perf proper #509: 3.17s, ~2.2%

[janbiedermann]

*_proper containing only the cache adjustment and regexp patch

[janbiedermann]

closing, got a opal-webpack-loader instead