skarayan

skarayan / gist:3239546

Created August 2, 2012 18:39

	class ActiveRecord::Base
	def self.inherited(klass)
	callbacks = [:before_validation, :before_save, :before_create, :before_update]

	callbacks.each do \|callback\|
	klass.send(callback) do
	return unless respond_to?(:updated_by) \|\| updated_by.nil?
	self.updated_by = Thread.current[:current_user]
	end
	end

skarayan / gist:3239208

Created August 2, 2012 18:06

Set current_user on all models in before_* callback

	# lib/user_stamp.rb
	module UserStamp
	def self.included(klass)
	callbacks = [:before_validation, :before_save, :before_create, :before_update]

	callbacks.each do \|callback\|
	klass.send(callback) do
	return unless respond_to?(:updated_by) \|\| updated_by.nil?
	self.updated_by = Thread.current[:current_user]
	end

skarayan / latency.txt

Created May 31, 2012 17:03 — forked from jboner/latency.txt

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
	Send 2K bytes over 1 Gbps network 20,000 ns
	Read 1 MB sequentially from memory 250,000 ns
	Round trip within same datacenter 500,000 ns
	Disk seek 10,000,000 ns