Grégory Horion gregory

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

Locate the section for your github remote in the .git/config file. It looks like this:

[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = [email protected]:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

From Meteor's documentation:

In Meteor, your server code runs in a single thread per request, not in the asynchronous callback style typical of Node. We find the linear execution model a better fit for the typical server code in a Meteor application.

This guide serves as a mini-tour of tools, trix and patterns that can be used to run async code in Meteor.

Basic async

Sometimes we need to run async code in Meteor.methods. For this we create a Future to block until the async code has finished. This pattern can be seen all over Meteor's own codebase:

	# Full code at https://gist.github.com/1406349/fa7c357b86790c183f3ef81ad6870b78bb2de343

	window.assets = {
	<%
	Dir.glob(Rails.root.join("app/assets/images/*/.*")).map do \|path\|
	img_name = path.gsub(Rails.root.join("app/assets/images/").to_s, "") %>
	"<%= img_name %>": "<%= asset_path(img_name) %>",
	<% end %>
	}

	html {
	background: #f06;
	background: linear-gradient(90deg, #cceecc,#eeeeee);
	min-height: 100%;
	}
	input[type=date] {
	background: #ccc;
	background: linear-gradient(90deg, #ddd, #ccc);
	border: 3px solid #eee;
	border-radius: 20px;

	# Capistrano configuration
	#
	# require 'new_relic/recipes' - Newrelic notification about deployment
	# require 'capistrano/ext/multistage' - We use 2 deployment environment: staging and production.
	# set :deploy_via, :remote_cache - fetch only latest changes during deployment
	# set :normalize_asset_timestamps - no need to touch (date modification) every assets
	# "deploy:web:disable" - traditional maintenance page (during DB migrations deployment)
	# task :restart - Unicorn with preload_app should be reloaded by USR2+QUIT signals, not HUP

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset=utf-8 />
	<title>Hello</title>
	<link rel="stylesheet" href="styles.css">
	</head>
	<body>
	Hello World
	</body>

	# An example of elasticsearch & Tire setup for ActiveRecord associations.
	#
	# A `Book has_many :chapters` scenario, with mapping and JSON serialization
	# for indexing associated models.
	#
	# Demonstrates three important caveats as of now:
	#
	# 1. You you have to use `touch: true` in the `belongs_to` declaration,
	# to automatically notify the parent model about the update.
	#

	#!/bin/sh

	NGINX_VERSION=1.3.8
	TMP_PATH=/tmp

	# Fetch and extract Nginx
	cd $TMP_PATH
	wget http://nginx.org/download/nginx-$NGINX_VERSION.tar.gz
	tar xvfz nginx-$NGINX_VERSION.tar.gz
	cd nginx-$NGINX_VERSION

	console.time('Zuneta-stream');
	/**
	* Modules dependencies
	*/

	var csv = require('csv-stream'),
	request = require('request'),
	objectMapper = require('object-mapper-stream'),
	solr = require('solr-client'),
	crypto = require('crypto');