Faster builds on Android - from 2 minutes to 2 seconds

What does a developer do when a build takes 2 minutes? He gets bored and his mind starts to wander. Maybe he opens Reddit, Twitter orMedium or checks his emails. Switching context and multitasking kills productivity. Every developer needs fast feedback, so he can get jump into the flow state. Therefore, fast builds are essential for productive development.

First, we take a look into Gradle Build Scans. There is no sense in accelerating your build without measuring and comparing the different outcomes. Gradle Build Scans help you to understand what happens during your build and which parts consume the most time.

Then we continue with basic tips to tweak your build with Gradle. Most of those tips are quick wins, because they only require a simple change in the Gradle build settings.

Finally, we take a look into how modularisation influences the build speed by an example. Doing it right you can change your business logic and run your tests in 2 seconds instead of 2 minutes.

Transcript

1. Faster Builds on Android From 2 Minutes to 2 Seconds @muffls Philipp Hofmann
2. Why is build speed important? Photo by Chris Liverani on Unsplash
3. How often do you hit compile?
4. 10 - 100 times per day?
5. From 2 minutes to 2 seconds.
6. We save 118 seconds.
7. Around 20 minutes to 2 hours per day.
8. Around 1,6 to 10 hours per week.
9. Reduce by 5 seconds.
10. 20 builds * 5s * 10 devs * 5 days = 1,4 hours / week
11. 100 builds * 5s * 10 devs * 5 days = 9,6 hours / week
12. What do you do when you have to wait 2 minutes? Photo by NordWood Themes on Unsplash
13. Or just 20 seconds? Photo by NordWood Themes on Unsplash
15. Photo by Stefan Cosma on Unsplash
16. Multitasking is killing your brain.
17. Multitasking lets your IQ drop significantly.
18. Like skipping whole night sleep.
19. Or smoking weed. Image Source
20. Knowing there is an unread email can reduce your IQ by 10 points!
21. Multitasking is especially bad for men.
22. It can reduce the IQ up to 15 points.
23. Turning you into a cognitive equivalent of an 8-year-old.
24. Multitasking Is Killing Your Brain CREDIT: Getty Images
25. Slow Builds Test automation is a pain. Slow Tests
26. Faster Builds
27. More Frequent Feedback Faster Builds
28. Faster Development More Frequent Feedback Faster Builds
29. Faster Development More Frequent Feedback Faster Builds
30. Faster Development More Frequent Feedback Faster Builds
31. Faster Development More Frequent Feedback Faster Builds
32. Faster Development More Frequent Feedback Faster Builds
33. Faster Development More Frequent Feedback Faster Builds Faster Builds Pyramid
34. • Measure Your Builds • Quick Wins to Fasten Your Builds • Modularisation and Build Speed • Some additional information about the topic on the chart • Maybe some numbers or a background information about some insights • Here is just another placeholder text to visualise the look of a filled info box INFO BOX Topics
35. Measure Your Builds Photo by Annie Spratt on Unsplash
36. $ ./gradlew assembleDebug --scan
37. $ ./gradlew assembleDebug --scan BUILD SUCCESSFUL in 1s 84 actionable tasks: 84 up-to-date Publishing a build scan to scans.gradle.com requires accepting the Gradle Terms of Service defined at https:// gradle.com/terms-of-service. Do you accept these terms? [yes, no]
38. $ ./gradlew assembleDebug --scan BUILD SUCCESSFUL in 1s 84 actionable tasks: 84 up-to-date Publishing a build scan to scans.gradle.com requires accepting the Gradle Terms of Service defined at https:// gradle.com/terms-of-service. Do you accept these terms? [yes, no] yes
39. $ ./gradlew assembleDebug --scan BUILD SUCCESSFUL in 1s 84 actionable tasks: 84 up-to-date Publishing a build scan to scans.gradle.com requires accepting the Gradle Terms of Service defined at https:// gradle.com/terms-of-service. Do you accept these terms? [yes, no] yes Gradle Terms of Service accepted.
40. $ ./gradlew assembleDebug --scan BUILD SUCCESSFUL in 1s 84 actionable tasks: 84 up-to-date Publishing a build scan to scans.gradle.com requires accepting the Gradle Terms of Service defined at https:// gradle.com/terms-of-service. Do you accept these terms? [yes, no] yes Gradle Terms of Service accepted. Publishing build scan...
41. $ ./gradlew assembleDebug --scan BUILD SUCCESSFUL in 1s 84 actionable tasks: 84 up-to-date Publishing a build scan to scans.gradle.com requires accepting the Gradle Terms of Service defined at https:// gradle.com/terms-of-service. Do you accept these terms? [yes, no] yes Gradle Terms of Service accepted. Publishing build scan... https://gradle.com/s/glklref6wdxr6
46. Create Build Scans https://guides.gradle.org/creating-build-scans/
47. $ ./gradlew assembleDebug --profile
50. Profile Your Build https://developer.android.com/studio/build/optimize-your-build#profile
51. Gradle Profiler https://github.com/gradle/gradle-profiler
52. Talaiot https://github.com/cdsap/Talaiot
54. $ ./gradlew clean cleanBuildCache
55. Measure Optimise
56. Quick Wins to Fasten Your Builds Photo by Richard R Schünemann on Unsplash
57. Update your Tools Photo by Todd Quackenbush on Unsplash
58. Update Gradle
61. Improving build speed in Android Studio https://medium.com/androiddevelopers/improving-build-speed-in-android- studio-3e1425274837
62. Update JVM
63. Update Android Studio and SDK Tools
64. Update Android Plugin for Gradle
65. • Gradle • JVM • Android Studio and SDK Tools • Android Plugin for Gradle Update
66. Use Apply Changes
67. gradle.properties
68. Caching org.gradle.caching=true
69. If neither a task’s inputs nor its output have changed since the last time it was run, Gradle will not run it again.
70. Enabled by default. Since Android Plugin 2.3.0 https://developer.android.com/studio/build/build-cache
72. Gradle Build Cache https://docs.gradle.org/current/userguide/build_cache.html
73. Incremental Compilation kotlin.incremental=true
74. Incremental annotation processor kapt.incremental.apt=true
75. Parallel Builds org.gradle.parallel=true
76. Create a build variant for development
77. flavorDimensions "mode" productFlavors { dev { dimension "mode" resConfigs "en", "xxhdpi" buildConfigField "long", "TIMESTAMP", "0L" } full { dimension "mode" } }
78. Quick wins 1. Update your Tools 2. Use Apply Changes 3. Caching 4. Incremental Compilation 5. Parallel Builds 6. Build Variant for Develop Photo by Richard R Schünemann on Unsplash
79. More Stuff
80. Scope annotation processing
81. Apply only needed plugins
82. apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-android-extensions' apply plugin: 'maven-publish' apply plugin: 'kotlin-kapt' apply plugin: 'talaiot' apply plugin: 'io.gitlab.arturbosch.detekt' apply plugin: 'org.jlleitschuh.gradle.ktlint'
83. Improving the Performance of Gradle Builds https://guides.gradle.org/performance/
84. Check your memory settings org.gradle.jvmargs= -Xmx3g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
85. Java Performance Tuning https://dzone.com/articles/java-performance-tuning
86. Optimize your build speed https://developer.android.com/studio/build/optimize-your-build
87. 19 tips for Gradle in Android projects — 2019 Edition https://medium.com/google-developer-experts/19-tips-for-gradle-in-android- projects-2019-edition-11af704eb06e
88. Modularisation
89. Modules can speed up your build, but can also slow down your build.
90. 1. Build modules in parallel
95. Example
96. Small app with one module.
100. Optimise • Update gradle and gradle plugin • Update Kotlin • Enable parallel builds and incremental compilation • Split up code into multiple modules
102. Reduced build time for around 25%.
103. 2. Compilation avoidance
106. api implementation vs
107. api implementation Module A Module B
108. Module A Module B Module C Foo api
109. Module A Module B Module C Foo api
110. Module A Module B Module C Foo api
111. Module A Module B Module C Foo implementation Module A Module B Module C Foo api
112. Module A Module B Module C Foo implementation Module A Module B Module C Foo api
113. Module A Module B Module C implementation Foo Module A Module B Module C Foo api
114. Module A Module B Module C Foo implementation Module A Module B Module C Foo api
115. Module A Module B Module C implementation Foo Module A Module B Module C Foo api
116. Module A Module B Module C Foo implementation Module A Module B Module C Foo api ModuleB is part of my Public API ModuleB is my Implementation Detail
117. Module A Module B Module C Foo implementation Module A Module B Module C Foo api ModuleB is part of my Public API ModuleB is my Implementation Detail
118. Module A Module B Module C Foo implementation Module A Module B Module C Foo api ModuleB is part of my Public API ModuleB is my Implementation Detail
119. @FMuntenescu Florina Muntenescu
120. Change
123. 18 seconds when in layout
124. 7 seconds when in Fragment
125. Change
128. 18 seconds when in layout
129. 6 seconds when in layout
130. 6 seconds when in layout 3 times faster
131. 7 seconds when in Fragment
132. 3 seconds when in Fragment
133. 3 seconds when in Fragment 2,3 times faster
134. Change Run
135. 65 seconds
136. Change Run
137. Change Run
138. 65 seconds
139. 9 seconds
140. 9 seconds 7 times faster
141. Build just what you need • Build only the code you want to check. • Let you iterate faster on your feature modules.
142. 3. Faster Tests
143. Run tests 15 seconds
144. Run tests 4 seconds
145. I promised 2 seconds.
146. Plain Kotlin or Java No Android dependencies
148. https://medium.com/google-developer-experts/19-tips-for-gradle-in-android-projects-2019-edition-11af704eb06e :libjava:assemble of the base java plugin
149. https://medium.com/google-developer-experts/19-tips-for-gradle-in-android-projects-2019-edition-11af704eb06e :lib1:assembleDebug of the com.android.library
150. Create pure Java Kotlin / Libraries
151. Advantages of Multiple Modules
152. Advantages of Multiple Modules 1. Build modules in parallel 2. Compilation avoidance 3. Faster tests 4. And all the other advantages … (Reusability, Maintainability, SOLID, …)
153. Sum it up
154. Photo by Richard R Schünemann on Unsplash Quick wins 1. Update your tools 2. Use Apply Changes 3. Use Gradle caching 4. Incremental compilation 5. Parallel builds 6. Build variant for develop
155. Create pure Java Kotlin / Libraries
156. Advantages of multiple modules 1. Build modules in parallel 2. Compilation avoidance 3. Faster tests
157. I optimise the build speed!
158. Measure Optimise
159. Faster Builds
160. More Frequent Feedback Faster Builds
161. Faster Development More Frequent Feedback Faster Builds
162. @muffls Philipp Hofmann Faster Development More Frequent Feedback Faster Builds
163. @muffls Philipp Hofmann Faster Development More Frequent Feedback Faster Builds