展开查看详情
1 .《BUCK在大规模iOS开发中的应用实践》
演讲者／陈坤
2 . Airbnb iOS Stats
• 80 commits/day to master (PRs are squashed)
• 500+ builds/week
• 71 iOS contributors last month
3 . Airbnb iOS Stats
• Multi apps
• Monorepo
• 900k lines of code
• 67% Swift
• 25% Javascript
• 8% Objective-C
• 80 internal frameworks + 25 Cocoapods + 2 Carthage
4 . Main Challenges
• Multi-Repos
• Hard to refactor
• Non-atomic changes, complex
versioning
• Cocopods encourages multi
repos.
5 . Main Challenges
• Xcode project management
• Resolving .xcproj conflicts.
• Hard to maintain dependencies.
• Hard for modernization.
• Hard to change build settings.
• CI build/test performance
6 . Airbnb change to use Monorepo
• Unified versioning, one source of
truth.
• Atomic changes.
• Flexible team boundaries and code
ownership.
• Large scale refactoring, codebase
modernization.
• Works for BUCK.
8 .Use Buck as the build system
9 . Build Tool Landscape
• Cocoapods
• Carthage
• BUCK
• xctool
• xcodebuild
• Swift Package Manager
• …
10 . Cocoapods
• Airbnb now only uses Cocoapods for 3rd party libraries.
• We used it for internal UI frameworks.
• Why it doesn’t work us:
• Slow to resolve, complex interdependencies.
• Not designed for monorepo.
11 . BUCK helps
• Designed for monorepo.
• Easy and clean dependency management.
• Encouraging modernization.
• Generate project for Xcode.
• More important: Faster build/test.
12 . Why using BUCK
• Build Time
• Building with multi-threading
• Cache aggressively
• App Size
• Merging modules into single binary
• Saving spaces in keep multiple copies of same resource
• Dev Efficiency
• Reducing effort in maintaining Cocoapods
• Creating new module easier by adding BUCK file
• Running tests with one line command
• Review diffs in Xcode project changes
13 . BUCK File
• Every framework/app has a BUCK file.
• Buck tool is written in Java, but BUCK file is python script.
• Define build rules and build targets.
• Build targets
• What and how to compile.
• Specify dependencies (transitive)
15 .Power of python script
16 . BUCK DAG
• Explicit dependency, no hidden
state.
• Dependencies are transitive.
• DAG powers the build speed and
cache.
17 . Faster Build
• BUCK is deterministic, output only determined by declared input.
• Cache
• Disk cache.
• Http cache.
• https://github.com/uber/buck-http-cache
• Parallelize build/test.
19 .How Buck builds iOS app
20 . How apple_library works
1. Input: *.h. Output: Module.hmap.
2. Input: *.swift, Module.hmap. Output: Module.o,
Module.swiftmodule, Module-Swift.h
3. Input: *.m, Module.hmap, Module-Swift.h. Output: *.o for each *.m.
4. Input: *.o, Module.o. Output: libModule.a.
21 . BUCK Commands
• build
• buck build //ios:AirbnbPackage_Alpha
• buck build AirbnbAlpha
• Generate project
• buck project //ios:Airbnb
• Query
• buck query “deps(//ios:Airbnb)”
22 .Airbnb Dependency Graph
TODO… Attach an image here
24 . Mix Languages 1
• Auto import objective-c to Swift
• -import-underlying-module
doesn’t work
• Explicitly pass bridging headers.
25 . Mix Languages 2
• @import doesn’t work in objective-C due to no
module.modulemap.
• Use #import in our own codebase.
• For generated *-Swift.h, use customize script
to do transform.
• https://github.com/airbnb/buck/commit/93453
a5730445c0dd799872b6e8bba49233430d7
26 . Mix Languages 3
• Bridging header can’t import
headers under current module.
• Update BUCK to include the
generated header map for current
library.
• https://github.com/facebook/buck/ Can’t #import <Greeter/Greeter.h>
in the bridging header
pull/1164
27 . Work with Cocopods
• Still use Cocopods to install
packages.
• Manually create and maintain a
BUCK file.
• We can do better:
• Hook into Podfile to generate
BUCK file automatically.
• But we are moving off from
Cocoapods.
29 . Others
• Support prebuilt_cxx_library in BUCK project generation
• Support umbrella headers
• Cocoapod generate umbrella headers named as Module-
umbrella.h
• Buck assuming all module header named as Module.h
• swiftc compliant if a public header file is not included in module
header
热门城市
