Cache Me If You Can

DroidKaigi 2025

Transcript

1. Cache Me If You Can 2025.09.12 DroidKaigi 2025 RyuNen344
2. Cache Me If You Can 2025.09.12 DroidKaigi 2025 RyuNen344 🐘
3. Materials
4. Ice Break
5. ͜Μͳܦݧ͋Γ·ͤΜ͔
6. ϚϧνϞδϡʔϧͳͷʹϏϧυ͕஗ ͍ɾɾɾɾ Cache͕ޮ͍ͯͳͦ͞͏ɾɾɾ
7. Android Gradle PluginΛ্͛ͨΒ Ϗϧυ͕յΕͨ
8. ΧελϜλεΫͷCache͕ޮ͔ͳ͍
9. GradleΑ͘Θ͔Βͳ͍ɾɾɾ
10. Agendas 1. Today's Goals 2. Why Gradle? How the Android Gradle Plugin works? 3. Lifecycle and Lifecycle-aware, everywhere 4. Cache of Gradle 5. Faster, Faster, Faster 6. Key Takeaways
11. Today’s Goal • Understands basic concepts of Gradle • Taming Android Gradle Plugin → The ABCs of Faster Gradle Builds
12. ⚠ Caution ⚠ • ίϯηϓτɾߟ͑ํ͕ϝΠϯ • Ϗϧυ͕N෼୹͘ͳͬͨɾNˋߴ଎Խͨ͠ͳͲ͸φγ • GradleɾAndroid Gradle Pluginͷ͓࡞๏ʹ஫ྗ
13. Why Gradle?
14. Why Gradle? • Project and Task • Gradle can do anything • Easy to cache
15. Project and Task
16. Project and Task ./gradlew :sub-project-B:Task c Task c <- Task b <- Task 1
17. Project and Task • Extension as Gradle Plugin • Several Language Support by Of fi cial Gradle Plugin • C++, Swift and multiple JVM based languages C++
18. Gradle can do anything
19. Easy to cache • Gradle watches Task inputs/outputs • Developer just de fi ne deterministic input and Gradle Task action
20. How the Android Gradle Plugin works?
21. How AGP? :app:assembleDebug +--- :app:mergeDebugNativeDebugMetadata | \--- :app:preDebugBuild | \--- :app:preBuild \--- :app:packageDebug +--- :app:compileDebugJavaWithJavac +--- :app:compressDebugAssets +--- :app:l8DexDesugarLibDebug +--- :app:mergeDebugAssets * +--- :app:mergeDebugJavaResource +--- :app:mergeExtDexDebug +--- :app:mergeLibDexDebug +--- :app:mergeProjectDexDebug +--- :app:preDebugBuild * +--- :app:processDebugManifestForPackage +--- :app:processDebugResources * +--- :app:stripDebugDebugSymbols +--- :app:validateSigningDebug +--- :app:writeDebugAppMetadata \--- :app:writeDebugSigningConfigVersions • Assemble task depends on many tasks
22. How AGP? :app:assembleDebug +--- :app:mergeDebugNativeDebugMetadata | \--- :app:preDebugBuild | \--- :app:preBuild \--- :app:packageDebug +--- :app:compileDebugJavaWithJavac +--- :app:compressDebugAssets +--- :app:l8DexDesugarLibDebug +--- :app:mergeDebugAssets * +--- :app:mergeDebugJavaResource +--- :app:mergeExtDexDebug +--- :app:mergeLibDexDebug +--- :app:mergeProjectDexDebug +--- :app:preDebugBuild * +--- :app:processDebugManifestForPackage +--- :app:processDebugResources * +--- :app:stripDebugDebugSymbols +--- :app:validateSigningDebug +--- :app:writeDebugAppMetadata \--- :app:writeDebugSigningConfigVersions • Assemble task depends on many tasks • AGP tells Gradle what the inputs and output of the Assemble task
23. How AGP? :app:assembleDebug +--- :app:mergeDebugNativeDebugMetadata | \--- :app:preDebugBuild | \--- :app:preBuild \--- :app:packageDebug +--- :app:compileDebugJavaWithJavac +--- :app:compressDebugAssets +--- :app:l8DexDesugarLibDebug +--- :app:mergeDebugAssets * +--- :app:mergeDebugJavaResource +--- :app:mergeExtDexDebug +--- :app:mergeLibDexDebug +--- :app:mergeProjectDexDebug +--- :app:preDebugBuild * +--- :app:processDebugManifestForPackage +--- :app:processDebugResources * +--- :app:stripDebugDebugSymbols +--- :app:validateSigningDebug +--- :app:writeDebugAppMetadata \--- :app:writeDebugSigningConfigVersions • Assemble task depends on many tasks • AGP tells Gradle what the inputs and output of the Assemble task When and Where does AGP tell that to Gradle?
24. Lifecycle and Lifecycle-aware, everywhere Gradle has a lifecycle
25. Lifecycle and Lifecycle-aware, everywhere • Gradle has a lifecycle
26. Initialization Phase • Read settings.gradle and recognize project structure • Specify dependency resolution strategies • Apply settings plugin
27. Con fi guration Phase • Read project’s build.gradle • Apply plugin to project • plugin creates con fi guration and tasks • Resolve dependencies • Graph resolution phase • Artifact resolution phase • Execute build scripts
28. Execution Phase • Execute tasks • Determine which tasks to execute by the task execution graphs • UP-TO-DATE and FROM-CACHE mean that Gradle has skipped a task by using incremental builds or the build cache
29. Also, AGP has a lifecycle AGP's Lifecycle
30. AGP's Lifecycle • Key points to understand AGP's Lifecycle
31. AGP's Lifecycle
32. AGP's Lifecycle • In old Variant API could make a variant disabled after creation • This can break the Task Graph(DAG) • It’s not good for Build Cache(even Con fi guration Cache)
33. AGP's Lifecycle
34. Lifecycle and Lifecycle-aware, everywhere
35. Wrap-up Part 1 • Gradle has a lifecycle • Gradle manages task dependencies and forms a DAG • Gradle reuses task results based on task input/output • Android Gradle Plugin also has a lifecycle • Recent API changes in AGP are to conform to Gradle's lifecycle • Old Variant API is scheduled to be deprecated in AGP 9.0.0, removed in 10.0.0, so it's recommended to migrate to the new API now
36. Before We Get to the Cache of Gradle • Idempotence • same input must produce the same output • Performance • appropriate granularity of cache makes high cache hit rate • cache hit is faster than re-execution
37. Cache of Gradle
38. Cache of Gradle : UP-TO-DATE Incremental build: `UP-TO-DATE`
39. Cache of Gradle : UP-TO-DATE
40. Cache of Gradle : UP-TO-DATE
41. Cache of Gradle : FROM-CACHE
42. Cache of Gradle : FROM-CACHE • Based on: • Hash of the task implementation class • All declared inputs • Task Identi fi er • Normalized content hash of fi le inputs used as fi ngerprint • build script is also included in key calculations (e.g. `doFirst`, `doLast`) • Env and System Props will not include unless explicitly declared as input
43. Cache of Gradle : Reusing con fi guration cache
44. Cache of Gradle : Reusing con fi guration cache When hit con fi skip con fi Skip
45. Cache of Gradle : Reusing con fi guration cache • Based on: • GRADLE_USER_HOME • init script • included build scripts • Custom Value Source • System Property and environment • etc… • Requirements: • implements java.io.Serializable
46. Wrap-up Part 2 • Incremental build and Build cache • re-use task results based on task input/output • Con fi guration cache • re-use task graph based on con fi guration inputs • Gradle uses different scopes and targets of cache to speed up builds in multiple ways • Con fi guration Cache became the preferred execution mode • Update your API to prevent issues, same as AndroidComponents API
47. Faster, faster, faster
48. Faster, faster, faster • Make input/output/con fi gurations more deterministic • Optimize project structure
49. Faster, faster, faster • First of all, enabling cache features
50. Make input/output more deterministic • Make input/output/con fi gurations more deterministic • Optimize project structure
51. Make input/output more deterministic • De fi ne @Input and @Output • To enable incremental builds, de fi ne an output property even for tasks that don’t have output • Use Gradle Provider or Property API, instead of Primitive class
52. Make input/output more deterministic • When inputs have changed, outputs must change • Avoid using non-declared inputs (Do not use Env or system prop inside TaskAction) •Annotate with @CacheableTask
53. Make input/output more deterministic • Avoid using random value as inputs • Use abstracted fi le paths so that the cache does not depend on the environment • Do not edit task output in build script
54. Make input/output more deterministic https://docs.gradle.org/current/userguide/incremental_build.html#sec:task_input_output_annotations
55. Make con fi guration more deterministic • Can't build project, after adding `org.gradle.con fi guration- cache=true` 😇
56. Make con fi guration more deterministic • Do not use `afterEvaluate` block • `afterEvaluate` block executes after con fi guration phase • `afterEvaluate` can break con fi guration phase result
57. Make con fi guration more deterministic • Do not touch non- serializable objects in execution time
58. Make con fi guration more deterministic • Use `ProjectLayout` or `BuildLayout` API to access fi les instead of `project` • Use injected `{FileSystem| Archive|Exec}`Operations to access fi les instead of `project`
59. Make con fi guration more deterministic • Use `ProviderFactory` API to access environment variables, system properties, external process results instead of `System` or direct execution
60. Make con fi gurations more deterministic https://docs.gradle.org/current/userguide/ con fi guration_cache_requirements.html#con fi g_cache:requirements:use_project_during_execution
61. Use AndroidComponents API • Use AndroidComponents API for deterministic con fi guration
62. Use AndroidComponents API • AndroidComponents API enables correct integration into the build process
63. Use Android Components API https://github.com/android/gradle-recipes
64. Optimize project structure • Android app developer needs fast build 1. Adoption of Jetpack Compose 2. Multi-module as a prerequisite
65. Optimize project structure 1.Remove redundant Gradle plugin from sub-project 2.Remove redundant dependency (library or project) 3.Do not con fi gure build variant/project fl avor on library module, use DI
66. Optimize project structure
67. Optimize project structure Improve cache hit rate & Narrow re-compile scope
68. Optimize project structure
69. Optimize project structure
70. Optimize project structure
71. Use Build Scan® • Gradle Knows Gradle Better Than You Know about Gradle • Visualize parallelism on Web UI
72. Use Develocity® Plugin • You can visualize without metadata publication • Visualize parallelism on IntelliJ and Android Studio
73. Key Takeaways • Gradle has a lifecycle, AGP also has a lifecycle • Gradle has different scopes and targets of cache to speed up builds in multiple ways • Make input/output/con fi gurations more deterministic • Use Gradle's provided APIs instead of `project` or `System` • Modify artifacts through AndroidComponents API • Optimize project structure to reduce re-compilation scope and increase parallelism • Use Build Scan and Develocity Plugin
74. About Me • Bunjiro Miyoshi (id: RyuNen344) • KMPΛֶΜͩΒͳ͔ͥGradleͷ஌͕ࣝ૿͑ͨ • Kodee͘Μݟ͔͚ͨΒͥͻ #KodeeEverywhere ͷϋογϡλάΛ͚ͭͯᄁ͖Λʂ
75. Appendix
76. Q. What’s next ? A. Lazy Con fi guration • Gradle 8.14.3 : Con fi gurations are initialized lazily • https://docs.gradle.org/8.14.3/ release- notes.html#con fi gurations-are- initialized-lazily • AGP 8.12.0 supports lazy con fi guration • https://issuetracker.google.com/ issues/416349489
77. Q. What’s next ? A. Isolated Projects • https://docs.gradle.org/current/userguide/isolated_projects.html • Isolated Projects extends the con fi guration cache • the con fi guration model of Gradle projects are "isolated" from each other • Make con fi guration cache more immutable • Make con fi guration cache safely run in parallel
78. Improvements of o ff i cial documents • JetBrains - Working with Gradle • https://www.jetbrains.com/guide/java/tutorials/working-with-gradle/ • Android Developers - Con fi gure your build • https://developer.android.com/studio/build • Android Developers - Write Gradle plugins • https://developer.android.com/build/extend-agp • Gradle - Improve the Performance of Gradle Builds • https://docs.gradle.org/current/userguide/performance.html • Gradle - Cookbook • https://cookbook.gradle.org/
79. EOF