Ruby 1.9: It works!
ihower@handlino.com
2009/4/18
OSDC.TW

Ruby 1.9: It (must) works!
ihower@handlino.com
2009/4/18
OSDC.TW

?
• a.k.a. ihower
• http://ihower.idv.tw/blog/
• http://twitter.com/ihower
• 2006 Ruby
• ( ) Rails Developer
• http://handlino.com
• http://registrano.com

Agenda
• Overview
• What’s changed?
• What’s New?
(External Interater, M17N, The Threading Model)
• Ruby 1.9 on Rails

1. Overview

Ruby 1.8.6
• Ruby 1.8.6, release at 2007/3/12
• Stable
• Performance sucks
• Memory leaks
• NewRelic Report 69.4%
http://railslab.newrelic.com/2009/04/01/the-state-of-the-stack-a-ruby-on-rails-benchmarking-report

Ruby 1.8.7
• Ruby 1.8.7 release at 2008/5/31
• 1.9
• gems, library ( 1.8.6 )
• JRuby 1.8.7
• NewRelic Report 14.5%

Ruby 1.9
• Ruby 1.9.0 release development version in
2007/12/25
• Ruby 1.9.1 release stable/production version
in 2009/1/30
• Better performance
• Better encoding support

Ruby Implementations
production
• Ruby 1.8.6, 1.8.7 (MRI, Matz’ Ruby Interpreter)
• EngineYard 1.8.6
MBARI GC patch http://www.infoq.com/news/2009/01/ruby-patches-fix-leaks
• Ruby 1.9.1 (YARV)
• JRuby
• Ruby1.8.6 1.9
• Ruby Enterprise Edition(REE)
• Ruby 1.8.6 GC memory leak

Ruby Implementations
production
• MacRuby (based on Objective-C)
• Rubinius (Engine yard project)
• MagLev (based on smalltalk)
• IronRuby (based on Microsoft .NET)
• Cardinal (based on Parrot VM)

Performance ( 1.8 2~2.5 )
http://antoniocangiano.com/category/ruby-benchmark-suite/
http://github.com/acangiano/ruby-benchmark-suite/

Ubuntu : Intel® Q6600® quad-core
Computer Language Benchmarks Game
http://shootout.alioth.debian.org/

2. What’s changed?

Ordered Hash
{ :a => 1, :b=> 2, :c => 3 }.merge( :d => 4 )
1.8 {:a=>1, :d=>4, :b=>2, :c=>3}
1.9 {:a=>1, :b=>2, :c=>3, :d=>4}

new Hash literal
config = { :foo => 1234, :bar => 6789 }
1.8,1.9
Person.find(:all, :conditions => { :name => 'ihower' } )
config = { foo: 1234, bar: 6789 }
1.9
Person.find(:all, :conditions => { name: 'ihower' } )

Hash syntax
=>
{1,2,3,4}
1.8 => {1=>2, 3=>4}
{1,2,3,4}
1.9
=> syntax error, unexpected ',', expecting tASSOC

Hash#select
hash = { :a => 1, :b => 2, :c => 3 }
hash.select{ |k, v| v > 1 }
[[:b, 2], [:c, 3]]
1.8
{:b=>2, :c=>3}
1.9

Array#to_s, Hash#to_s
1.8 1.9
[1,2,3,4].to_s [1,2,3,4].to_s
=> \"1234\" => \"[1, 2, 3, 4]\"
{1=>2,3=>4}.to_s {1=>2,3=>4}.to_s
=> \"1234\" => \"{1=>2, 3=>4}\"

case syntax
name = case name = case
when x == 1 : \"one\" when x == 1
1.8 when x == 2 : \"two\" \"one\"
1.8,1.9
else \"many\" when x == 2
end \"two\"
else
\"many\"
end
name = case
when x == 1 then \"one\"
when x == 2 then \"two\"
1.8,1.9
else \"many\"
end

block’s parameter always local
local
x = \"foo\"
y = \"bar\"
[1,2,3].each do |x|
y=x+1
end
1.8 [x,y] => [3, 4] 1.9 [x,y] => [\"foo\", 4]

block’s parameter always local
local
x = \"foo\"
y = \"bar\"
[1,2,3].each do |x|
y=x+1
end
1.8 [x,y] => [3, 4] 1.9 [x,y] => [\"foo\", 4]

block-local variable
local
bar = \"ihower\"
1.9
bar = \"ihower\"
1.8,1.9
[1,2,3].each do |val; bar|
[1,2,3].each do |val|
bar = val
foo = val
end
bar = val
end
bar => \"ihower\"
foo # NameError: undefined
local variable or method `foo’
bar => 3

block-local variable
local
bar = \"ihower\"
1.9
bar = \"ihower\"
1.8,1.9
[1,2,3].each do |val; bar|
[1,2,3].each do |val|
bar = val
foo = val
end
bar = val
end
bar => \"ihower\"
foo # NameError: undefined
local variable or method `foo’
bar
bar => 3

block can accept block argrments
proc1 = lambda do |a, *b, &block|
pa
pb
pc
block.call
end
proc1.call(1,2,3,4) { puts \"in block1\" }
#
1
[2,3,4]
\"in block1\"

new lambda literal
lambda
lambda { |a| a*3 }.call(4)
1.8,1.9
# => 12
lambda { |a| a*3 }[4]
1.8,1.9
# => 12
->(a) { a*3 }.(4)
1.9 # => 12

def my_if(condition, then_clause, else_clause)
if condition
then_clause.call
else
else_clause.call
end
end
5.times do |val|
my_if (val < 3),
-> { puts \"#{val} is small\" },
-> { puts \"#{val} is big\" }
end
#
0 is small
1 is small
2 is small
3 is big
4 is big

def my_while(cond, &body)
while cond.call
body.call
end
end
a=0
my_while -> { a < 3 } do
puts a
a += 1
end
#
0
1
2

Kernel.proc
, do not use it!
• proc lambda
1.8
•
1.9 proc Proc.new

BasicObject
root
Class.superclass.superclass => Object
1.8,1.9
1.8 Class.superclass.superclass.superclass => nil
Class.superclass.superclass.superclass => BasicObject
1.9
BasicObject.superclass => nil
BasicObject.instance_methods
=> [:==, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__]
metaprogramming
blank canvas

standard library changes
• + Rubygems
• no longer needed require ‘rubygems’
• + Rake
• no longer gem install rake
• ~ Test::Unit replaced by MiniTest
• - soap, jcode...etc, some rarely used, old
libraries

3. What’s new?

External Iterator

Iterators
to_enum
Internal External
1.9
1.8,1.9
arr = [ 1, 2, \"ihower\" ] arr = [ 1, 2, \"ihower\" ]
arr.each do |a| enum_a = arr.to_enum
puts a # Enumerators ( each)
end
enum_a.next # => 1
# => 1 enum_a.next # => 2
# => 2 enum_a.next # => \"ihower\"
# => \"ihower\"

Enumerators
1.9 1.9
arr = [ 1, 2, \"ihower\" ]
h = { foo: \"567\", bar: \"890\" }
enum_a =
enum_h = h.to_enum
arr.to_enum(:each_with_index)
enum_h.next
# => [:foo, \"567\"]
enum_a.next # => [1, 0]
enum_h.next
enum_a.next # => [2, 1]
# => [:bar, \"890\"]
enum_a.next # => [\"ihower\", 2]

StopIteration exception
1.9
short_enum = [1, 2, 3].to_enum
long_enum = ('a'..'z').to_enum
loop do
puts \"#{short_enum.next} #{long_enum.next}\"
end
# => 1-a
# => 2-b
# => 3-c

StopIteration exception
1.9
short_enum = [1, 2, 3].to_enum
long_enum = ('a'..'z').to_enum
loop do
puts \"#{short_enum.next} #{long_enum.next}\"
end
# => 1-a
StopIteration
# => 2-b
# => 3-c

Enumerator from iterator
iterator method
1.9
arr = [ 1, 2, \"ihower\" ]
enum_a = arr.each # Enumerator
enum_a.next # => 1
enum_a.next # => 2
enum_a.next # => \"ihower\"

Enumerators.new
code block
1.9 seq = Enumerator.new do |yielder|
n1 = 0
n2 = 1
loop do
n3 = n1 + n2
yielder.yield n3
n1 = n2
n2 = n3
end
end
seq.next # 1
seq.next # 2
2.times { puts seq.next }
#3
#5

Enumerator objects are
also enumerable
1.9
seq.first(10)
# => [1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
seq.to_a
# Don’t do this if your Enumerator has infinite elements

M17N
(Multilingualization)

In Ruby 1.8, a String is always
just a collection of bytes

Ruby 1.8 String fails
>> \" \".reverse
1.8
=> \"\\207\\226 \\344\"
>> \" \".size
=> 6

Ruby 1.8 Regexp
UTF-8
• Support None (n or N), EUC (e or E),
Shift_JIS (s or S), UTF-8 (u or U)
>> \" \".scan(/./u)
1.8,1.9
=> [\" \", \" \"]

Use Regexp to handle String
Regexp
>> \" \".scan(/./u).reverse.join
1.8,1.9
=> \" \"
>> \" \".scan(/./u).size
=> 2

$KCODE = “U”
or ruby -KU
• regular expressions default encoding
• $KCODE = \"U\" terminal
>> \" \"
1.8
=> \"\\344\\270\\255\\346\\226\\207\"
>> $KCODE='u'
>> \" \"
=> \" \"

Unicode codepoint
Ruby 1.8 UTF-8
>> \" \".unpack(\"U*\")
1.8,1.9
=> [20013, 25991]
>> \" \".unpack(\"U*\").reverse.pack(\"U*\")
=> \" \"
>> \" \".unpack(\"U*\").size
=> 2

Unicode codepoint(cont.)
Rails ActiveSupport
>> \" \".chars # in Rails
1.8,1.9
=> #<ActiveSupport::Multibyte::Chars:0x25aebbc
@wrapped_string=\" \">
>> \" \".chars.size
=> 2

iconv library
UTF-8 data
• C Library, it’s fast.
• convert your encoding to UTF-8
• handle it
• export back to your encoding

jcode library
too simple, not useful
$KCODE = 'UTF8'
1.8
require 'jcode'
str = \" \"
str.size # 9
str.jsize # 2

No enough encodings
supported in Ruby 1.8
• String Encoding
• Regexp
• encoding Regexp letter
• #String.upcase encoded data valid?
• $KCODE
• String, IO object, program source

pick one encoding, likely Unicode, and works all data in one format? No.
Ruby 1.9 make it possible to work
with data with 83 encoding.

>> Encoding.name_list
=> [\"ASCII-8BIT\", \"UTF-8\", \"US-ASCII\", \"Big5\", \"CP949\", \"Emacs-Mule\", \"EUC-JP\",
\"EUC-KR\", \"EUC-TW\", \"GB18030\", \"GBK\", \"ISO-8859-1\", \"ISO-8859-2\", \"ISO-8859-3\",
\"ISO-8859-4\", \"ISO-8859-5\", \"ISO-8859-6\", \"ISO-8859-7\", \"ISO-8859-8\",
\"ISO-8859-9\", \"ISO-8859-10\", \"ISO-8859-11\", \"ISO-8859-13\", \"ISO-8859-14\",
\"ISO-8859-15\", \"ISO-8859-16\", \"KOI8-R\", \"KOI8-U\", \"Shift_JIS\", \"UTF-16BE\",
\"UTF-16LE\", \"UTF-32BE\", \"UTF-32LE\", \"Windows-1251\", \"BINARY\", \"IBM437\",
\"CP437\", \"IBM737\", \"CP737\", \"IBM775\", \"CP775\", \"CP850\", \"IBM850\", \"IBM852\",
\"CP852\", \"IBM855\", \"CP855\", \"IBM857\", \"CP857\", \"IBM860\", \"CP860\", \"IBM861\",
\"CP861\", \"IBM862\", \"CP862\", \"IBM863\", \"CP863\", \"IBM864\", \"CP864\", \"IBM865\",
\"CP865\", \"IBM866\", \"CP866\", \"IBM869\", \"CP869\", \"Windows-1258\", \"CP1258\",
\"GB1988\", \"macCentEuro\", \"macCroatian\", \"macCyrillic\", \"macGreek\",
\"macIceland\", \"macRoman\", \"macRomania\", \"macThai\", \"macTurkish\", \"macUkraine\",
\"CP950\", \"stateless-ISO-2022-JP\", \"eucJP\", \"eucJP-ms\", \"euc-jp-ms\", \"CP51932\",
\"eucKR\", \"eucTW\", \"GB2312\", \"EUC-CN\", \"eucCN\", \"GB12345\", \"CP936\", \"ISO-2022-
JP\", \"ISO2022-JP\", \"ISO-2022-JP-2\", \"ISO2022-JP2\", \"ISO8859-1\", \"Windows-1252\",
\"CP1252\", \"ISO8859-2\", \"Windows-1250\", \"CP1250\", \"ISO8859-3\", \"ISO8859-4\",
\"ISO8859-5\", \"ISO8859-6\", \"Windows-1256\", \"CP1256\", \"ISO8859-7\",
\"Windows-1253\", \"CP1253\", \"ISO8859-8\", \"Windows-1255\", \"CP1255\", \"ISO8859-9\",
\"Windows-1254\", \"CP1254\", \"ISO8859-10\", \"ISO8859-11\", \"TIS-620\", \"Windows-874\",
\"CP874\", \"ISO8859-13\", \"Windows-1257\", \"CP1257\", \"ISO8859-14\", \"ISO8859-15\",
\"ISO8859-16\", \"CP878\", \"SJIS\", \"Windows-31J\", \"CP932\", \"csWindows31J\",
\"MacJapanese\", \"MacJapan\", \"ASCII\", \"ANSI_X3.4-1968\", \"646\", \"UTF-7\",
\"CP65000\", \"CP65001\", \"UTF8-MAC\", \"UTF-8-MAC\", \"UCS-2BE\", \"UCS-4BE\", \"UCS-4LE\",
\"CP1251\", \"locale\", \"external\", \"internal\"]

All String are Encoded
• In Ruby 1.9 a String is a collection of
encoded characters.
raw bytes Encoding
>> \" \".encoding.name
1.9
=> \"UTF-8\"
Encoding
object

String works in characters
1.9 >> \" \".reverse
=> \" \"
>> \" \".size
=> 2
>> \" \".bytesize
=> 6

String Indexing
1.9
1.8
>> \"abc\"[0] >> \"abc\"[0]
=> 97 => \"a\"
>> \" \"[1] >> \" \"[1]
=> 184 => \" \"
>> \"abc\"[0].ord
=> 97

!
In Ruby 1.9, String has attached
Encoding object, and works in
characters.

Transcoding
utf8 = \" \"
1.9
utf8.bytesize # 6
utf8.bytes.to_a # [230, 184, 172, 232, 169, 166]
big5 = utf8.encode(\"big5\")
big5.encoding.name # ”Big5”
big5.bytesize # 4
big5.bytes.to_a # [180, 250, 184, 213]

Transcoding fails
str = \"Résumé\"
1.9 str.encode(\"big5\")
=> Encoding::UndefinedConversionError: \"\\xC3\\xA9\"
from UTF-8 to Big5
from (irb):2:in `encode'
from (irb):2
from /usr/local/bin/irb19:12:in `<main>'

Force Transcoding
byte data
utf8 = \" \"
1.9
big5 = utf8.encode(\"big5\")
big5.valid_encoding?
=> true
big5.force_encoding(\"utf-8\")
big5.valid_encoding?
=> false

Force Transcoding fails
big5.valid_encoding? # false
1.9 big5 =~ /123456/
=> ArgumentError: invalid byte sequence in UTF-8
from (irb):11
from /usr/local/bin/irb19:12:in `<main>'

Encoding.compatible?
: ASCII with a bigger Encoding
ascii = \"my \".force_encoding(\"ascii\")
1.9
utf8 = \"Résumé\"
#
Encoding.compatible?(ascii, utf8)
#<Encoding:UTF-8>
#
my_resume = ascii + utf8
puts my_resume # \"My Résumé\"
puts my_resume.encoding.name # UTF-8

Encoding.compatible?
big5 = \" \".encode(\"big5\")
1.9
utf8 = \"Résumé\"
#
Encoding.compatible?(big5, utf8) # nil
#
big5 + utf8
=> Encoding::CompatibilityError: incompatible character
encodings: Big5 and UTF-8
from (irb):25
from /usr/local/bin/irb19:12:in `<main>'

String Iteration
each
• Strings are no longer enumerable
• Ruby 1.8 each() has been removed
•
1.9 Ruby 1.9 use explicit iterator
• each_line
• each_byte
• each_char
• each_codepoint

What’s default encoding?
? encoding ?

program source encoding
magic comment
# encoding: UTF-8
#!/usr/bin/env ruby -w
# encoding: UTF-8
# coding: UTF-8
# -*- coding: UTF-8 -*-

program without magic comment
ruby foobar.rb # US-ASCII
ruby -e foobar.rb irb # OS ($LC_CTYPE, $LANG)
ruby -KU foobar.rb # UTF-8

program source
encoding error
invalid multibyte char (US-ASCII)

IO Object
1.9
# encoding: utf-8
f = File.open(\"big5.txt\",\"r:big5\")
puts f.external_encoding # Big5
puts f.gets.encoding # Big5

IO Object
1.9
# encoding: utf-8
f = File.open(\"big5.txt\",\"r:big5:utf-8\")
puts f.external_encoding # Big5
puts f.internal_encoding # UTF-8
puts f.gets.encoding # UTF-8

IO Object
1.9
# encoding: utf-8
f = File.open(\"another_big5.txt\", \"w:big5\")
puts f.external_encoding # Big5
data = \" \"
puts data.encoding.name # UTF-8
f << data

IO Object
1.9
# encoding: utf-8
f = File.open(\"another_big5.txt\", \"w:big5\")
puts f.external_encoding # Big5
data = \" \"
puts data.encoding.name # UTF-8
f << data

Regexp has encoding too
• Oniguruma engine
1.9
http://www.geocities.jp/kosako3/oniguruma/
/\\w/.encoding
• Same basic API
=> #<Encoding:US-ASCII>
• better performance
/ /.encoding
=> #<Encoding:UTF-8>
• support for a lot of encoding
• extended syntax

Default Encoding Overview
• String literal program source
• Symbols Regexp 7-bit
US-ASCII program source
• IO external_encoding OS
• ruby -E
• Encoding.external_encoding

The Threading model

Fibers
(semi-coroutine)
code block

f = Fiber.new {
1.9
2.times do
puts \"Fiber say hi\"
Fiber.yield #
puts \"Fiber say bye\"
end
}#
>> f.resume
# Fiber say hi
>> f.resume
# Fiber say bye
# Fiber say hi
>> f.resume
# Fiber say bye
>> f.resume
FiberError: dead fiber called
from (irb):78:in `resume'
from (irb):78
from /usr/local/bin/irb19:12:in `<main>'

Fibers
• Enumerator
• fiber library fiber
object
• (Ruby 1.8 continuation
continuation kernel library)
• ... zzz

Native Threads
• Green threads
1.8
Ruby thread native thread
• Native (operation system) thread
1.9
Ruby thread native thread

GIL
Giant Interpreter Lock
•
1.9
C extension libraries
thread safe
Thread
( Ruby Threads JRuby)

4. Ruby on Rails

Ruby 1.9 on Rails
• Rails 2.3.2 or edge
• mysql-ruby driver for Ruby 1.9
• Passenger(mod_rails) or Thin

Upgrade issue
• program source encoding problem
• invalid multibyte char # encoding: UTF-8
• encoding compatibility problem
• ACSII-8BIT (binary) UTF-8 String
• http://github.com/hectoregm/mysql-ruby (UTF-8 friendly)
• some gem, plugins are not Ruby 1.9 compatible
• http://isitruby19.com/

Benchmark
• Rails 2.3.2 production mode
• No DB, just render :text => 'hello'
• My MacBook Pro 2.2G
• httperf

Performance
Reply rate [replies/s]
min avg max stddev
Ruby 1.8.6 241.8 258.3 267.4 14.4
Mongrel
1.1.5
Ruby 1.8.6 244.6 260.9 271.2 11.4
mod_rails
Ruby 1.9.1 264.0 269.5 273.4 4.9
mod_rails
Ruby 1.8.6 244.5 273.2 299.6 22.7
Thin 1.0.0
Ruby 1.9.1 348.4 363.2 371.2 12.8
Thin 1.0.0

Performance
Ruby 1.9 Rails Stack !!
400
300
Ruby 1.8.6/Mongrel 1.1.5
Ruby 1.8.6/mod_rails edge
200 Ruby 1.9.1/mod_rails edge
Ruby 1.8.6/Thin 1.0.0
Ruby 1.9.1/Thin 1.0.0
100
0
Reply rate [replies/s]

Performance
Ruby 1.9 Rails Stack !!
400
300
Ruby 1.8.6/Mongrel 1.1.5
Ruby 1.8.6/mod_rails edge
200 Ruby 1.9.1/mod_rails edge
Ruby 1.8.6/Thin 1.0.0
Ruby 1.9.1/Thin 1.0.0
100
0
Reply rate [replies/s]

5. Conclusion

TIOBE Programming Community Index for April 2009

Ruby challenge
• Ruby 1.9 change a lot and 1.8 is slow and
should be deprecated.
• Migrate to Ruby 1.9 is the big challenge
in 2009.

Reference
• Understanding M17n
http://blog.grayproductions.net/articles/understanding_m17n
• Books
• Programming Ruby 1.9 (Pragmatic)
• The Ruby Programming Language (O’Reilly)
• Ruby Best Practices (O’Reilly)
• The Well-Grounded Rubyist (Manning)
• Slide
• MigrationToRuby 1.9
• Ruby 1.9: What to Expect
http://slideshow.rubyforge.org/ruby19.html
• Matz on Ruby 1.9

Other reference links
• http://svn.ruby-lang.org/repos/ruby/tags/v1_9_1_0/NEWS
• http://blog.nuclearsquid.com/writings/ruby-1-9-what-s-new-what-s-changed
• http://blog.grayproductions.net/articles/getting_code_ready_for_ruby_19
• http://dablog.rubypal.com/2009/1/14/10-things-to-be-aware-of-in-moving-to-
ruby-1-9
• http://dablog.rubypal.com/2009/1/16/son-of-10-things-to-be-aware-of-in-
ruby-1-9
• http://blog.kineticweb.com/articles/2009/01/30/ruby-1-9-1-the-other-features

Thank you.

Bonus

Object#tap
puts \"dog\".reverse
.tap{ |o| puts \"reversed: #{o}\" }
.upcase
#
reversed: god
GOD