igrigorik

# Equivalent to mysqladmin ext -ri10
#  - that is, if mysqladmin ext -ri10 works on your box
#  - in my case it didn't...
#
# Reports MySQL variable changes for a certain time period
#
# Running: ruby mysql-var-stats.rb interval

require 'rubygems'
require 'ruport'

igrigorik

#!/usr/bin/env ruby

require 'rubygems'
require 'mini_magick'

BLANK = 'blank.png'    # 1x1px white png
$text = 'hello, world' # text to write

img = MiniMagick::Image.from_file(BLANK)

igrigorik

class Array; def sum; inject( nil ) { |sum,x| sum ? sum+x : x }; end; end
class Array; def mean; self.sum/self.size.to_f; end; end
class Array; def variance; mean = self.mean; Math.sqrt(inject( nil ) { |var,x| var ? var+((x-mean)**2) : ((x-mean)**2)}/self.size.to_f); end; end

# inputs a random variable, sets mean = 0 and variance = 1
def standardize_random_variable(x)
  mean = x.mean
  variance = x.variance
  x.map!{|a| (a-mean)/variance }
end

igrigorik

require 'rubygems'
require 'benchmark'
require 'facets/dictionary'
require 'rbtree'

n = 1000000
Benchmark.bm do |x|
  @h = Hash.new
  x.report("Hash insert") { n.times do @h[rand(n)] = 1 end }
  x.report("Hash access") { n.times do @h[rand(n)] end }

igrigorik

##
# sync api: return values and exceptions

begin
  images = []

  results = RestClient.get('http://google.com/search?q=ruby')
  Hpricot(results).find('a').each{ |link|
    page = RestClient.get(link)
    begin

igrigorik

require "rubygems"
require "tokyocabinet"
require "benchmark"

include TokyoCabinet
records = 1000000

hdb = HDB::new  # Hash database; acts as a key value store
hdb.open("casket.hdb", HDB::OWRITER | HDB::OCREAT)

igrigorik

EventMachine Notes

Adapted to Markdown format from rom Aman Gupta's gist at: http://gist.github.com/79224

Using:

require 'rubygems'
require 'eventmachine'

EM::run Takes over the Process

igrigorik

require "rubygems"
require "curb"

module Curl
  class Easy
    def self.fetch(req, &blk)
      curl = Curl::Easy.new(req['url'], &blk)

      curl.follow_location = true
      curl.max_redirects = 3

igrigorik

# async_sinatra_example.ru
require 'sinatra'

# Normally Sinatra::Base expects that the completion of a request is 
# determined by the block exiting, and returning a value for the body.
#
# In an async environment, we want to tell the webserver that we're not going
# to provide a response now, but some time in the future.
#
# The a* methods provide a method for doing this, by informing the server of

igrigorik

##
# sync api: return values and exceptions

begin
  images = []

  results = RestClient.get('http://google.com/search?q=ruby')
  Hpricot(results).find('a').each{ |link|
    page = RestClient.get(link)
    begin