Reduce Build Times and Get Home Eariler

Swift is a robust language, but at the same time, it means that many things are done at build time. Swift is now the standard for iOS development, but as a result, we suffer longer builds and it deprives us of our precious time. Time is more valuable than anything.

In this session, I will show you how to improve Swift’s build times and gain productivity in three parts:

- Measurement
- Improvement
- Avoid building all together!

Transcript

1. Reduce Build Times and Get Home Earlier Yusei Nishiyama @yuseinishiyama
2. • iOS, Android, Web • 63 countries • 17 languages • 63M+ MAU (Japan) • 35M+ MAU (Outside Japan) https://info.cookpad.com/en https://cookpad.com/en
3. Distributed Team
4. Try Error
5. Try Error
6. Let’s improve the registration screen…
7. Let’s improve the registration screen… • Implement
8. Let’s improve the registration screen… • Implement • Tweak constraints
9. Let’s improve the registration screen… • Implement • Tweak constraints • Test with older iOS versions
10. Let’s improve the registration screen… • Implement • Tweak constraints • Test with older iOS versions • Fix tests
11. Let’s improve the registration screen… • Implement • Tweak constraints • Test with older iOS versions • Fix tests • Wait for CI
12. How many times 
 did you build so far?
16. You are not efficient
18. ?
19. 3 steps to improve • Measurement • Visualization • Improvement
20. What I will “not” talk about • Annotate all types explicitly • Write as much as code in a single file • Get your Mac Pro
21. 3 steps to improve • Measurement • Visualization • Improvement
22. “Premature optimization is the root of all evil.”
 
 — Donald Knuth —
23. Display build duration $ defaults write com.apple.dt.Xcode ShowBuildOperationDuration YES
24. Build Process • Dependency Manager (CocoaPods, Carthage) • Compile source files • Run Scripts (Linter, Formatter)
25. cookpad/dokumi • Open source • Advanced Lint tool • Comments issues on a pull request • Runs on CI server
26. Violated linter rules Failed tests
27. require 'benchmark'
 
 def measure(*args, &block) start_time = Time.now tms = Benchmark.measure(args, &block) @data << ExecutionLog.new(args, tms, start_time) end Benchmark
28. Build Process • Dependency Manager (CocoaPods, Carthage) • Compile source files • Runs Scripts (Linter, Formatter)
29. Build Process • Dependency Manager (CocoaPods, Carthage) • Compile source files • Function A • Function B • … • Runs Scripts (Linter, Formatter)
30. Warn long function bodies
31. Time function bodies $ pbpaste | grep '.[0-9]ms' | sort -nr | head -20
32. RobertGummesson/ BuildTimeAnalyzer-for-Xcode
33. Is that data easy to manipulate? • Integrate data collection into our build process • Flexible format which doesn’t not restrict how we use it
34. giginet/xcprofiler • A CLI tool to time body functions • Easy to integrate into build process • Flexible output (stdout, JSON, Custom)
36. require 'xcprofiler' profiler = Xcprofiler::Profiler.by_product_name('MyApp') profiler.reporters = [ Xcprofiler::StandardOutputReporter.new(limit: 20, order: :time), Xcprofiler::JSONReporter.new(output_path: 'result.json'), Xcprofiler::BlockReporter.new do |executions| do_something(executions) end, ] profiler.report! Custom Reporter
37. xactivitylog • You can access build logs under DerivedData • xactivitylog is just gzip. You can check the content as a plain text just by unzipping it
38. 3 steps to improve • Measurement • Visualization • Improvement
39. CI Server cookpad/dokumi
40. CI Server cookpad/dokumi
41. CI Server cookpad/dokumi
42. CI Server cookpad/dokumi
43. CI Server cookpad/dokumi
44. InfluxDB • Only purpose-built platform for any time-based data • Written in Go • Built-in HTTP API • SQL-like query language • Answer queries in real-time • Rich client libraries
45. CI Server cookpad/dokumi
46. Grafana • Rich metrics dashboard and editor • Fast rendering • Support InfluxDB as a data source • Query editor
47. Build time visualization
48. Other metrics
49. 3 steps to improve • Measurement • Visualization • Improvement
50. Test with Real Data $ cloc
 
 github.com/AlDanial/cloc v 1.72 T=3.40 s (153.3 files/s, 16646.6 lines/s) ------------------------------------------------------------------------------- Language files blank comment code ------------------------------------------------------------------------------- Swift 497 8944 3122 43831 JSON 18 0 0 522 Objective C 3 37 5 166 C/C++ Header 4 19 6 27 ------------------------------------------------------------------------------- SUM: 522 9000 3133 44546 -------------------------------------------------------------------------------
51. Test with Real Data • 40,000 lines of Swift code • CocoaPods • 38 direct dependencies and 60 libraries • Linter in build phases • CI archives the app and distributes it for internal testing
52. Machine specs • CI • Mac mini (Late 2014) • 3 GHz Intel Core i7 • Memory 16GB • 256GB SSD • Local • MBP (Retina, 15-inch, Late 2013) • 2.3 GHz Intel Core i7 • Memory 16 GB • 256GB SSD
53. (Local clean build: 330s)
55. Whole Module Optimization
56. WMO without Optimization
57. (Local clean build: 160s)
58. https://swift.org/blog/whole-module-optimizations/
59. post_install do |installer| installer.pods_project.targets.each do |target| target.build_configurations.each do |config| config.build_settings['SWIFT_OPTIMIZATION_LEVEL'] = '-Owholemodule' unless config.name == 'Release' other_swift_flags = config.build_settings['OTHER_SWIFT_FLAGS'] || ['$(inherited)'] other_swift_flags << '-Onone' config.build_settings['OTHER_SWIFT_FLAGS'] = other_swift_flags end end end end
60. (Local clean build: 118s)
61. Time Function Bodies
63. post_install do |installer| installer.pods_project.targets.each do |target| target.build_configurations.each do |config| config.build_settings['SWIFT_OPTIMIZATION_LEVEL'] = '-Owholemodule' unless config.name == 'Release' other_swift_flags = config.build_settings['OTHER_SWIFT_FLAGS'] || ['$(inherited)'] other_swift_flags << '-Onone' other_swift_flags << '-Xfrontend' other_swift_flags << '-debug-time-function-bodies' config.build_settings['OTHER_SWIFT_FLAGS'] = other_swift_flags end end end end
64. (Local clean build: 130s)
65. F
66. Carthage + github "ReactiveX/RxSwift" ~> 3.4 + github "RxSwiftCommunity/RxRealm" + github "realm/realm-cocoa" ~> 2.4 + github "danielgindi/Charts" ~> 3.0.2 - pod 'RxSwift', '3.3.1' - pod 'RxCocoa', '3.3.1' - pod 'RxRealm', '0.5.2' - pod 'RealmSwift', '2.4.4' Cartfile Podfile
69. (Local clean build: 68s)
70. Partial Lint lint() { while read filename; do if [[ "${filename##*.}" == "swift" ]]; then ${SWIFT_LINT} lint --path "${filename}" --quiet fi done } FORK_POINT=`git merge-base --fork-point origin/develop` git diff $FORK_POINT --name-only | lint
71. (Local clean build: 55s)
72. Do you really need to build your entire app?
74. Playground
75. Playground
76. Real World Prototyping class ViewController: UITableViewController { let myView = MyView() override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .myColor view.addSubview(myView) } }
77. You need “existing” code for prototyping
78. Embedded Playground
83. Framework for Playground
89. How to use it in Playground import UIKit @testable import MyPlayground let color = UIColor.myGreen
91. Code Modularization import UIKit @testable import YourUIKit let color = UIColor.myGreen
92. Framework Oriented Architecture Feature A Design Feature B Feature C Network Persistence Core
93. Microservice Architecture https://martinfowler.com/articles/microservices.html
94. Easy to prototype
95. High testability
96. Autonomous Teams
97. Independent Technology Stack 
 (Swift, Objc, React Native, Flux)
98. Complex Workflow
99. Dynamic Frameworks make your app slow to launch
100. dylib Loading Time Total pre-main time: 4.2 seconds (100.0%) dylib loading time: 4.0 seconds (94.4%) rebase/binding time: 93.32 milliseconds (2.1%) ObjC setup time: 44.64 milliseconds (1.0%) initializer time: 98.30 milliseconds (2.3%)
101. WWDC16 406 
 “Optimizing App Startup Time"
102. Recap • You can get detailed build time information • Visualization helps you to identify the bottleneck • You can improve build time in many ways (WMO and Carthage are highly effective) • Modularization makes your prototyping easier
103. References • http://techlife.cookpad.com/entry/2015/06/04/dokumi-en • http://developear.com/blog/2016/12/30/Speed-Swift- Compilation.html • https://swift.org/blog/whole-module-optimizations/ • https://medium.com/@LogMaestro/adding-playgrounds-to- your-xcode-project-79d5ea0c7087 • http://frameworkoriented.io/ • https://developer.apple.com/videos/play/wwdc2016/406/
104. I’ll summarize this talk on our engineering blog
 https://sourcediving.com/
105. The presentation is available on
 https://speakerdeck.com/yuseinishiyama/reduce-build-times- and-get-home-eariler
106. Any Question?