Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
The Value of Being Lazy
Search
Erik Berlin
November 24, 2015
Programming
3
800
The Value of Being Lazy
…or How I Made OpenStruct 10X Faster
Presented at Rails Israel 2015.
Erik Berlin
November 24, 2015
Tweet
Share
More Decks by Erik Berlin
See All by Erik Berlin
Enumerator::Lazy
sferik
2
580
Ruby Trivia 3
sferik
0
720
Ruby Trivia 2
sferik
0
770
Ruby Trivia
sferik
2
1.3k
💀 Symbols
sferik
5
1.9k
Content Negotiation for REST APIs
sferik
8
1k
Writing Fast Ruby
sferik
630
62k
Mutation Testing with Mutant
sferik
5
1.1k
Other Decks in Programming
See All in Programming
NixOS + Kubernetesで構築する自宅サーバーのすべて
ichi_h3
0
1.2k
Go言語はstack overflowの夢を見るか?
logica0419
0
520
CSC509 Lecture 08
javiergs
PRO
0
240
Pythonに漸進的に型をつける
nealle
1
120
組込みだけじゃない!TinyGo で始める無料クラウド開発入門
otakakot
2
360
はじめてのDSPy - 言語モデルを『プロンプト』ではなく『プログラミング』するための仕組み
masahiro_nishimi
4
13k
CSC509 Lecture 06
javiergs
PRO
0
270
Cursorハンズオン実践!
eltociear
2
1.2k
Goで実践するドメイン駆動開発 AIと歩み始めた新規プロダクト開発の現在地
imkaoru
4
890
開発組織の戦略的な役割と 設計スキル向上の効果
masuda220
PRO
8
1.4k
Webサーバーサイド言語としてのRustについて
kouyuume
1
4.5k
monorepo の Go テストをはやくした〜い!~最小の依存解決への道のり~ / faster-testing-of-monorepos
convto
2
530
Featured
See All Featured
The Art of Delivering Value - GDevCon NA Keynote
reverentgeek
16
1.7k
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
127
54k
Building Applications with DynamoDB
mza
96
6.7k
Build The Right Thing And Hit Your Dates
maggiecrowley
37
2.9k
BBQ
matthewcrist
89
9.8k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
46
2.5k
How to Think Like a Performance Engineer
csswizardry
27
2.1k
Raft: Consensus for Rubyists
vanstee
140
7.2k
The Illustrated Children's Guide to Kubernetes
chrisshort
49
51k
Leading Effective Engineering Teams in the AI Era
addyosmani
7
580
For a Future-Friendly Web
brad_frost
180
10k
We Have a Design System, Now What?
morganepeng
53
7.8k
Transcript
THE VALUE OF BEING LAZY or How I Made OpenStruct
10X Faster Erik Michaels-Ober @sferik
In Ruby, everything is an object. ∀ thing thing.is_a?(Object) #=>
true
In Ruby, every object has a class. ∀ object object.respond_to?(:class)
#=> true
In Ruby, every class has a class. ∴ Object.respond_to?(:class) #=>
true Object.class #=> Class
You can use classes to create new objects: object =
Object.new object.class #=> Object
You can use classes to create new classes: klass =
Class.new klass.class #=> Class
Usually, we create classes like this: class Point attr_accessor :x,
:y def initialize(x, y) @x, @y = x, y end end
You can replace such simple classes with structs: Point =
Struct.new(:x, :y)
OpenStruct requires even less definition: point = OpenStruct.new point.x =
1 point.y = 2
In this way, OpenStruct is similar to Hash: point =
Hash.new point[:x] = 1 point[:y] = 2
You can even initialize OpenStruct with a Hash: point =
OpenStruct.new(x: 1, y: 2) point.x #=> 1 point.y #=> 2
So why use OpenStruct instead of Hash?
Test double validator = OpenStruct.new expect(validator).to receive(:validate) code = PostalCode.new("94102",
validator) code.valid?
API response user = OpenStruct.new(JSON.parse(response)) user.name #=> Erik
Configuration object def options opts = OpenStruct.new yield opts opts
end
So OpenStruct is useful…but slow.
None
Steps to optimize code 1. Complain that code is slow
on Twitter 2. ??? 3. Profit
Actual steps to optimize code 1. Benchmark 2. Read code
3. Profit
Actual steps to optimize code 1. Benchmark 2. Read code
3. Profit
require "benchmark/ips" Point = Struct.new(:x, :y) def struct Point.new(0, 1)
end def ostruct OpenStruct.new(x: 0, y: 1) end Benchmark.ips do |x| x.report("ostruct") { ostruct } x.report("struct") { struct } end
Comparison: struct: 2927800.2 i/s ostruct: 84741.1 i/s - 34.55x slower
Actual steps to optimize code 1. Benchmark 2. Read code
3. Profit
def initialize(hash = nil) @table = {} if hash hash.each_pair
do |k, v| k = k.to_sym @table[k] = v new_ostruct_member(k) end end end
def new_ostruct_member(name) name = name.to_sym unless respond_to?(name) define_singleton_method(name) { @table[name]
} define_singleton_method("#{name}=") { |x| @table[name] = x } end name end
def method_missing(mid, *args) len = args.length if mname = mid[/.*(?==\z)/m]
@table[new_ostruct_member(mname)] = args[0] elsif len == 0 if @table.key?(mid) new_ostruct_member(mid) @table[mid] end end end
def initialize(hash = nil) @table = {} if hash hash.each_pair
do |k, v| k = k.to_sym @table[k] = v new_ostruct_member(k) end end end
Before: struct: 2927800.2 i/s ostruct: 84741.1 i/s - 34.55x slower
After: struct: 2927800.2 i/s ostruct: 940170.4 i/s - 3.11x slower
None
None
git log --reverse lib/ostruct.rb
None
Lazy evaluation
Enumerator::Lazy
lazy_integers = (1..Float::INFINITY).lazy lazy_integers.collect { |x| x ** 2 }.
select { |x| x.even? }. reject { |x| x < 1000 }. first(5) #=> [1024, 1156, 1296, 1444, 1600]
require "prime" lazy_primes = Prime.lazy lazy_primes.select { |x| (x -
2).prime? }. collect { |x| [x - 2, x] }. first(5) #=> [[3, 5], [5, 7], [11, 13], [17, 19], [29, 31]]
module Enumerable def repeat_after_first unless block_given? return to_enum(__method__) { size
* 2 - 1 if size } end each.with_index do |*val, index| index == 0 ? yield *val : 2.times { yield *val } end end end
require "prime" lazy_primes = Prime.lazy lazy_primes.repeat_after_first. each_slice(2). select { |x,
y| x + 2 == y }. first(5) #=> [[3, 5], [5, 7], [11, 13], [17, 19], [29, 31]]
require "date" lazy_dates = (Date.today..Date.new(9999)).lazy lazy_dates.select { |d| d.day ==
13 }. select { |d| d.friday? }. first(10)
lazy_file = File.readlines("/path/to/file").lazy lazy_file.detect { |x| x =~ /regexp/ }
Being lazy is efficient.
Being lazy is elegant.
Thanks to: Zachary Scott ROSS Conf Rails Israel
Thank you