coreyhaines

--colour
-I app

panthomakos

#!/usr/bin/env ruby

require 'benchmark'

REGEXPS = [
  /^no such file to load -- (.+)$/i,
  /^Missing \w+ (?:file\s*)?([^\s]+.rb)$/i,
  /^Missing API definition file in (.+)$/i,
  /^cannot load such file -- (.+)$/i,
]

sj26

Patched ruby 1.9.3-p194 for 30% faster rails boot

What is?

This script installs a patched version of ruby 1.9.3-p194 with patches for boot-time performance improvements (#66 and #68), and runtime performance improvements (#83 and #84). It also includes the new backported GC from ruby-trunk.

Huge thanks to funny-falcon for the performance patches.

• http://github.com/ruby/ruby/pull/66
• http://github.com/ruby/ruby/pull/68

shakefu

# Option defaults
OPT="value"

# getopts string
# This string needs to be updated with the single character options (e.g. -f)
opts="fvo:"

# Gets the command name without path
cmd(){ echo `basename $0`; }

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

knewter

class FoodFightPlayCommandsController < LoggedInController
  def create
    command = FoodFightPlayCommand.new(params[:food_fight_play_command])
    command.person_id = current_person.id
    # Set up success / failure callbacks
    command.on_success = method(:on_success)
    command.on_failure = method(:on_failure)
    command.execute!
  end

steveklabnik

class SomeController < AC::Base
  def show
    foo = Foo.first
    bar = Bar.first
    
    show_model = ShowViewModel.new(foo, bar)

    render show_model
  end
end

stevenharman

me:

Is it possible to send a signal to a worker/process? I realize the platform sends SIGTERM and SIGKILL when restarting a dyno, but I need to send a USR1 to one of my workers to tell it to stop picking up new jobs. Normally this is achieved via kill -USR1 <pid>, but on the Heroku platform not only do we not know know the pid, we also don't run one-off commands on the same dyno.

Caio (heroku support):

We had this feature experimentally at some point but it was never productized. I recommend you find other ways to signal your processes, like setting a database flag.

me:

blowmage

class TasksController < ApplicationController
  def update
    if @task.update_attributes(params[:task])
      tracker = PostSaveTaskTracker.new(@task)
      TaskPusher.new(tracker, socket_id).push_changes
      TaskMailSender.new(tracker, current_user).deliver_email
      # success response
    else
      # failure respond
    end

ryanb

My issues with Modules

In researching topics for RailsCasts I often read code in Rails and other gems. This is a great exercise to do. Not only will you pick up some coding tips, but it can help you better understand what makes code readable.

A common practice to organize code in gems is to divide it into modules. When this is done extensively I find it becomes very difficult to read. Before I explain further, a quick detour on instance_eval.

You can find instance_eval used in many DSLs: from routes to state machines. Here's an example from Thinking Sphinx.

class Article < ActiveRecord::Base