calling `js :name` slows down sinatra extremely (in production too)

[doits]

i have the following asset configured:

assets do
    serve '/js', from: 'views/coffee'
    js :global, [
        '/js/webshim/src/extras/modernizr-custom.js',
        '/js/webshim/src/polyfiller.js',
        '/js/webshim/src/extras/custom-validity.js',
        '/js/vendor/*.js',
        '/js/parts/*.js',
        '/js/global.js',
        '/js/pages/*.js'
    ]    
end 

To render the following haml, it takes about 280ms:

!!!
%html 
  != js :global 

Removing the js :global, it cuts down the time to about 80ms:

!!!
%html

It does not matter if I am in production mode or test mode.

Reducing the number of assets help, about 120ms with this:

assets do
    serve '/js', from: 'views/coffee'
    js :global, [
        '/js/global.js',
    ]    
end 

So I assume looking up the files is causing it to slow down. Any chance to make this faster or at least have it in production mode fast?

[j15e]

Not enough details / 120ms is not that slow depending on the number of assets.

If you need performance for production env, you should build assets or use a cdn.

[lukesmith]

We're having performance issues too when the html is rendered. I think I've tracked it down to a performance problem with Sinatra::AssetPack::Options#glob.

I used MethodProfiler to get the following information when the application was running in the production environment using rackup -E production. Note this running on Windows.

Tracing from Sinatra::AssetPack::Package#paths_and_files ends up in Sinatra::AssetPack::Options#glob

MethodProfiler results for: Sinatra::AssetPack::Package
+---------------------+------------+-------------+--------------+-------------+-------------+
| Method              | Min Time   | Max Time    | Average Time | Total Time  | Total Calls |
+---------------------+------------+-------------+--------------+-------------+-------------+
| #to_production_html | 643.064 ms | 2077.208 ms | 1247.375 ms  | 4989.499 ms | 4           |
| #production_path    | 641.064 ms | 2076.208 ms | 1246.374 ms  | 4985.498 ms | 4           |
| #files              | 640.064 ms | 2071.207 ms | 1243.624 ms  | 4974.497 ms | 4           |
| #paths_and_files    | 640.064 ms | 2071.207 ms | 1243.624 ms  | 4974.497 ms | 4           |
| #link_tag           | 0.000 ms   | 1.000 ms    | 0.500 ms     | 2.000 ms    | 4           |
| #add_path_prefix    | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 4           |
| #css?               | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 2           |
| #js?                | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 4           |
+---------------------+------------+-------------+--------------+-------------+-------------+
MethodProfiler results for: Sinatra::AssetPack::Options
+-----------------+------------+-------------+--------------+-------------+-------------+
| Method          | Min Time   | Max Time    | Average Time | Total Time  | Total Calls |
+-----------------+------------+-------------+--------------+-------------+-------------+
| #glob           | 640.064 ms | 2070.207 ms | 1243.374 ms  | 4973.497 ms | 4           |
| #files          | 303.030 ms | 396.039 ms  | 331.433 ms   | 4971.497 ms | 15          |
| #ignored?       | 0.000 ms   | 1.000 ms    | 0.067 ms     | 1.000 ms    | 15          |
| #to_uri         | 0.000 ms   | 20.002 ms   | 0.018 ms     | 719.071 ms  | 39780       |
| #packages       | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 4           |
| #served         | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 4           |
| #app            | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 8           |
| #local_file_for | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 4           |
| #asset_hosts    | 0.000 ms   | 0.000 ms    | 0.000 ms     | 0.000 ms    | 8           |
+-----------------+------------+-------------+--------------+-------------+-------------+
MethodProfiler results for: Sinatra::AssetPack::BusterHelpers
+--------------------+----------+----------+--------------+------------+-------------+
| Method             | Min Time | Max Time | Average Time | Total Time | Total Calls |
+--------------------+----------+----------+--------------+------------+-------------+
| #cache_buster_hash | 0.000 ms | 5.001 ms | 1.250 ms     | 10.001 ms  | 8           |
| #add_cache_buster  | 0.000 ms | 5.001 ms | 1.250 ms     | 10.001 ms  | 8           |
+--------------------+----------+----------+--------------+------------+-------------+