bf4

Table of contents

• Concepts
• Reads
  • Basic Setup
  • Filtering
  • Custom Filtering
  • Sorting
  • Custom Sorting

bf4

module AMS
  module V09
    class Serializer < ActiveModel::Serializer

       def serializable_hash(adapter_options = nil,
                             options = {},
                             adapter_instance = self.class.serialization_adapter_instance)
         object.nil? ? nil : super
       end
    end

bf4

  # Finds and yields relations in batches. Adapted from record.find_in_batches since that yields
  # arrays and we want to operate on relationships.
  # Adapted from:
  #   https://github.com/rails/rails/blob/4-2-stable/activerecord/lib/active_record/relation/batches.rb#L98-L115
  def find_in_batches(target, batch_size: default_batch_size, start: nil)
    relation = target
    if logger && (target.arel.orders.present? || target.arel.taken.present?)
      logger.warn("Scoped order and limit are ignored, it's forced to be batch order and batch size")
    end
    relation = relation.reorder(target.send(:batch_order)).limit(batch_size)

bf4

Setup

• http://leiningen.org/ Get the repl
• Set up your ide (vim + fireplace, maybe atom, or be awesome with emacs. I don't use emacs)

Dip your beak

• https://learnxinyminutes.com/docs/clojure/ write this out in the repl to see what the code looks like.

The APIs are thorough and awesome

• https://clojure.org/about/rationale read this all the way through

bf4

/**
NOTE:
Assumes env contains aws credentials:
AWS_ACCESS_KEY_ID or AWS_ACCESS_KEY
AWS_SECRET_KEY_ID or AWS_SECRET_KEY
and AWS_REGION_NAME (e.g. 'US-EAST-1')

see EnvAuth() below
*/

bf4

message.to = 'Person Name <person@example.com>'
message.subject = 'Sample Subject'
# body is probably good enough, but you can set text_part/html_part below if you like
message.body = <<HERE.strip
Hey-

  This is a sample

Thanks
HERE

bf4

#!/bin/bash
# dontforget
#
# A stupid script for short term reminders in bash
#
# Arguments just need to contain a number and a bunch of words.
#
# The number can be anywhere in the arguments, but there shouldn't
# be any other numeric digits.
#

bf4

/ In app/views/shared/

#dev-badge
  span= Rails.env
  span It ain't production!

bf4

require 'warden/github'

class SidekiqGithubChecker
  def self.registered(app)
    app.helpers do
      def warden; env['warden'] end
      def github_organization_authenticate!(name)
        unless warden.user.organization_member?(name)
          halt [401, {}, ["You don't have access to organization #{name}"]]
        end

bf4

background

There are many options available for tuning ruby memory management: https://github.com/ruby/ruby/blob/trunk/gc.c#L7420-L7444

The one that gets the most attention is RUBY_GC_HEAP_GROWTH_FACTOR, which is the only one Heroku suggests adjusting: https://devcenter.heroku.com/articles/ruby-memory-use#gc-tuning

I've often wondered what the drawback was for setting RUBY_GC_HEAP_GROWTH_FACTOR quite low for a webapp.