joakimk

Single core cpu performance.

echo 'int main() { double i = 0; for(i = 0; i < 5000000000; i++) { 20%7 * i; } }' > /tmp/test.c && gcc /tmp/test.c -o /tmp/test && time /tmp/test && rm /tmp/test.c && rm /tmp/test

NOTE: It's not 100% reliable since it differs depending on compiler version.

Platform                   CPU                   Time
MacBookPro15,1 (Mid 2018)  i9 2.4 ghz            11.1 
iMac15,1 (Late 2014)       i7 4.0 ghz            11.7

PC (Early 2016, i5 4690k) i5 3.5 ghz 12.0

joakimk

For us this turned out to be that we had cached html generated by the rails 3 app that had the ASCII-8BIT encoding, clearing all html caches fixed this.

To arrive at this, we first added this debug code:

# if you reuse this: ensure it matches the method in your version of rails
# as the method is overwritten by this monkeypatch

# config/initializers/debug_encoding_errors.rb
ActiveSupport::SafeBuffer

joakimk

# I have not deeply researched the best way of doing this. This is just one way.
# Made this gist because there was no google result for this exact question so I had to dive into the code instead.

# Saving
cookies = browser.driver.cookies.instance_variable_get(:@browser).get_raw_cookies.map { |c| c.instance_variable_get(:@attributes) }
cookies_json = cookies.to_json

# Restoring
cookies = JSON.parse(cookies_json)
cookies.each do |c| 

joakimk

More info

• https://github.com/eeue56/elm-for-web-developers#can-i-enter-html-as-a-string
• https://github.com/evancz/elm-html/issues/54

joakimk

# This installs a PXE boot server.
#
# It's based on https://help.ubuntu.com/community/DisklessUbuntuHowto.
# It's been used with ubuntu-10.10-server-amd64.iso and ubuntu-10.10-server-i386.iso.
#
# It requires two network cards. One for access to the outside world and one
# for a private network of PXE clients. I've choosen this setup to not cause problems
# with DHCP on the normal network.
#
# It also requires that you have a second partition mounted on /nfsroot.

joakimk

This runs a build for a small elixir (phoenix) project in about 40 seconds by caching as much of the compiled files as possible.

We've been using this for months in multiple projects without any issues. Please ping be if there is any issues with this script and I'll update it.

It should be generic enough to work on any elixir app using mix.

If you have a elixir_buildpack.config, then enable that section in the build script to keep versions in sync!

2016-08-09: Updated to newer Erlang and Elixir and fixed curl command.

joakimk

Building custom ruby-alpine

Check the alpine version of the previous image.

alpine3.9 master$ docker run -it ruby:2.5.4-alpine sh
/ # cat /etc/alpine-release 
3.9.2
/ # ruby -v
ruby 2.5.4p155 (2019-03-13 revision 67245) [x86_64-linux-musl]

joakimk

class Controller
  include LazyLoad

  def show
    @model = Model.find(...)

    respond_to do |format|
      format.html do
        @html_specific_data = Model.find(...)
      end

joakimk

// Didn't find anything on google for this so I wrote my own. Use as a starting point if you have a similar problem.
// Please write comments if there is a better way to do this (or solve the same problem in another way) in webpack.

// Contents of config/webpack/environment.js:

const { environment } = require('@rails/webpacker')

// Generate undigested assets for use in embedded javascript, emails, etc.
// We previously used non-stupid-digest-assets for this.

joakimk

# Atom -> Init Script...

child = require "child_process"

runTestInTmux = (focus) ->
  editor = atom.workspace.getActiveTextEditor()
  editor.save()

  fullPath = editor.getPath()
  projectPath = atom.project.getDirectories()[0].getPath() + "/"