'Improving Xcode build time​' by Sameh Mabrouk

Sameh will describe few things:
- The problem of relatively high build times with CocoaPods
- How to deal with it
- How to handle it
- What Swift issues may arise while customizing your build process

This talk was made for CocoaHeads Kyiv #13 which took place Dec 16 2017.

Transcript

1. IMPROVING
   XCODE BUILD TIME
   One Approach
   2017-Sameh Mabrouk, Mobiquity - @same7mabrouk
   

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2. INDEX
   Problem
   Solutions/Approaches
   Demo
   Result
   References
   

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3. INDEX
   Problem
   Solutions/Approaches
   Demo
   Result
   References
   

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4. Our App build time takes around
   7-10 minutes on local machine
   20-30 minuts on CI
   

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5. Hard to do TDD(good excuse)
   Slow the development process
   

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6. INDEX
   Problem
   Solutions/Approaches
   Demo
   Result
   References
   

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7. Optimisation on code level
   More class extensions increase build time
   Type inference, Swift takes more time to infers the types
   

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8. Dependency management
   Change debug information formate to “DWARF”
   post_install do |installer|
   puts("Update debug pod settings to speed up build time")
   Dir.glob(File.join("Pods", "**", "Pods*{debug}.xcconfig")).each do |file|
   File.open(file, 'a') { |f| f.puts "\nDEBUG_INFORMATION_FORMAT = dwarf" }
   end
   end
   

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9. Dependency management
   Change debug information formate to “DWARF”
   post_install do |installer|
   puts("Update debug pod settings to speed up build time")
   Dir.glob(File.join("Pods", "**", "Pods*{debug}.xcconfig")).each do |file|
   File.open(file, 'a') { |f| f.puts "\nDEBUG_INFORMATION_FORMAT = dwarf" }
   end
   end
   simply changing one option in Xcode reduced the waiting time in 25 seconds: nice!
   

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10. Dependency management
    (CocoaPods)
    

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11. Dependency management
    (CocoaPods)
    Using Binaries/Frameworks instead of source code of dependencies
    

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12. Demo
    

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13. How to use Framework with CocoaPods
    vendored_frameworks
    

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14. How to use Framework with CocoaPods
    Update pod spec
    Add binary/framework to your remote repo
    Pod install - to get the framework
    

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15. Example1: Podspec
    Pod::Spec.new do |s|
    s.name = 'ObjectMapper'
    s.version = '2.2.8'
    s.license = 'MIT'
    s.summary = 'JSON Object mapping written in Swift'
    s.homepage = 'https://github.com/Hearst-DD/ObjectMapper'
    s.authors = { 'Tristan Himmelman' => 'tristanhimmelman@gmail.com' }
    s.source = { :git => 'https://github.com/Hearst-DD/ObjectMapper.git', :tag => s.version.to_s }
    s.watchos.deployment_target = '2.0'
    s.ios.deployment_target = '8.0'
    s.osx.deployment_target = '10.9'
    s.tvos.deployment_target = '9.0'
    s.pod_target_xcconfig = {
    'SWIFT_VERSION' => '3.1',
    }
    s.requires_arc = true
    s.ios.vendored_frameworks = 'framework/ObjectMapper.framework'
    end
    

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16. Example2: subspecs
    Pod::Spec.new do |s|
    s.name = 'BananaLib'
    s.version = '1.0'
    s.author = 'Banana Corp'
    s.license = 'Proprietary'
    s.homepage = 'http://banana-corp.local/banana-lib.html'
    s.summary = 'Chunky bananas!'
    s.default_subspec = 'Source'
    s.subspec 'Source' do |source|
    source.source = {
    :git => 'http://banana-corp.local/banana-lib.git',
    :tag => 'v1.0'
    }
    source.source_files = '**/*.swift'
    end
    s.subspec 'Binary' do |binary|
    binary.source = {
    :http => 'http://banana-corp.local/banana-framework.zip'
    }
    binary.vendored_frameworks = 'BananaFramework.framework'
    end
    end
    

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17. Add framework to remote repo
    

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18. Add framework to remote repo
    

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19. Automation?
    

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20. Shell script!!!, i don’t know?
    

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21. Let’s give it a try…
    

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22. #!/bin/bash
    # clonning remote git repo
    function lazyclone {
    url=$1" "$2" "$3;
    echo $url
    reponame=$(echo $url | awk -F/ '{print $NF}' | sed -e 's/.git$//');
    echo $reponame
    git clone $url $reponame;
    cd $reponame;
    }
    lazyclone $1" "$2" "$3
    # using carthage to create dynamic framework from .xcodeproj
    carthage build --no-skip-current
    cd "Carthage/Build/iOS"
    # Go back to repo main directory
    cd ..
    cd ..
    cd ..
    # Create a directory called framework that hold the binary
    mkdir framework
    # Copy .framework from Carthage/Build/iOS directory to framwork directory
    cp -R ${PWD}/Carthage/Build/iOS/$reponame.framework ${PWD}/framework
    cp -R ${PWD}/Carthage/Build/iOS/$reponame.framework.dSYM ${PWD}/framework
    # Change .podspec so it should contain s.ios.vendored_frameworks
    sed -i '' '/source_files/c\
    s.source_files = '"'""'"'
    $'\n'' ./${reponame}.podspec
    sed -i '' '/end/i\
    s.ios.vendored_frameworks = '"'"framework/${reponame}.framework"'"'
    $'\n'' ./${reponame}.podspec
    # Remove Carthage directory
    rm -r Carthage
    # Commit and push .podspec and framework to remote repo
    function lazyPush() {
    git add .
    git commit -a -m "$1"
    git push
    }
    lazyPush "Change pod spec to support dynamic framework + add dynamic framework"
    echo "Done!"
    echo "Now you have a framework for this dependency, just do pod install in your project to use it"
    echo "Have a good day!"
    

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23. Result
    Our project build time decreased by 2 minutes.
    From 7 minutes to 5 minutes
    

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24. Conclusion
    Optimizing your building process truly pays off.
    

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25. Conclusion
    It only requires spending some time on it once in a while,
    ideally only costing a few hours every few months.
    

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26. Conclusion
    It saves a considerable amount of time and money.
    

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27. Conclusion
    But, most importantly, it will make developers happier.
    

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28. Conclusion
    Engineering work, so it’s fun to do.
    

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29. References
    https://medium.com/@RobertGummesson/regarding-swift-build-time-
    optimizations-fc92cdd91e31
    https://medium.com/@RobertGummesson/regarding-swift-build-time-
    optimizations-fc92cdd91e31
    https://github.com/RobertGummesson/BuildTimeAnalyzer-for-Xcode
    https://jobs.zalando.com/tech/blog/speeding-up-xcode-builds/?
    gh_src=4n3gxh1
    https://jobs.zalando.com/tech/blog/how-the-zalando-ios-app-abandoned-
    cocoapods-and-reduced-build-time/?gh_src=4n3gxh1
    

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