Jirawat Karanwittayakarn LINE Thailand / Developer Relations Team Explore new strategies to increase your developer productivity with practical tips on how to accelerate your own Android Gradle builds and generate optimized APKs by Android Studio

1. Build your Android app
Faster and Smaller than ever
Jirawat Karanwittayakarn
Technology Evangelist, LINE THAILAND

2. Agenda • Overview of LINE MAN
• Tips for smaller app builds
• Techniques for faster app builds

3. AN ON-DEMAND ASSISTANT APP
WITH PROFESSIONAL SERVICES

4. YOUR DAILY LIFE ASSISTANT
FOOD
DELIVERY
CONVENIENCE
GOODS DELIVERY
MESSENGER
SERVICE
POSTAL / PARCEL
SERVICE
TAXI

5. JOINED DEVELOPER BUILD CLINIC
● Developer Build Clinic is one on one consulting
in build performance improvement provided by
Android Studio Team
● Have been part of it since 2016
● Throughout the years I have gathered tips and
advises from the team

6. ! ACTUAL RESULTS MAY VARY

7. TIPS FOR BUILDING
LINE MAN DRIVER APP SMALLER

8. CURRENT APP SIZE

9. Quick Recommendation: Use APK Analyzer

10. Tip 1: Remove
Unused Resources

11. Tip 2: Add just
Dependencies Needed
$ ./gradlew app:dependencies

12. android {
splits {
density {
enable true
// Specifies a list of screen densities Gradle should not create multiple APKs for.
exclude 'ldpi', 'mdpi'
// Specifies a list of compatible screen size settings for the manifest.
compatibleScreens 'small', 'normal', 'large', 'xlarge'
}
}
}
Tip 3: Build Multiple APKs for Screen Densities

13. android {
splits {
abi {
enable true
reset() // By default all ABIs are included, so use reset() and specify that you only want
// Specifies a list of ABIs that Gradle should create APKs for.
include 'x86', 'x86_64', 'arm64-v8a', 'armeabi-v7a'
universalApk false // Specifies that we don’t want to also generate a universal APK that includes all ABIs.
}
}
}
Tip 4: Build Multiple APKs for ABIs

14. android {
defaultConfig {
...
ndk {
abiFilters 'x86', 'x86_64', 'arm64-v8a', 'armeabi-v7a'
// armeabi, mips and mips64 has removed since NDK r17
}
}
}
Tip 5: Build an APK with Specific ABIs

15. android {
defaultConfig {
resConfigs 'en', 'th'
...
}
}
Tip 6: Remove Unused Alternative Resources

16. android {
buildTypes {
release {
minifyEnabled true
shrinkResources true
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
Tip 7: Shrink Unused Code and Resources

17. Tip 8: Use
Shape Drawable
• Support rectangle, oval, line and
ring shapes
• Support gradient, rounded corner
and outline stroke effects.

18. Tip 9: Use WebP
• Up to 30% smaller than PNGs
• Opaque - API level 15+
• With transparency - API level 18+

20. Tip 10: Use VectorDrawable
• Smaller than Bitmaps
• Resize for different screen densities
without loss of image quality
• API level 21 and higher
• API level <= 20 (use the Support Library)

21. CUMULATIVE IMPROVEMENT
9MB 7.9MB

22. TECHNIQUES FOR
BUILDING
LINE MAN DRIVER APP
FASTER
Knowledge from Developer Build Clinic by Android Studio Team
and “Speeding Up Your Android Gradle Builds” (Google I/O ’17)

23. CURRENT BUILDING SPEED
~ 3 mins

24. buildscript {
repositories {
jcenter()
+ google()
}
dependencies {
- classpath 'com.android.tools.build:gradle:3.0.0'
+ classpath 'com.android.tools.build:gradle:3.2.1'
}
...
}
Technique 1: Use Latest Android Plugin

25. productFlavors {
development {
minSdkVersion 21
...
}
}
Technique 2: Avoid Legacy Multidex

26. buildTypes {
...
debug {
splits.abi.enable = false
splits.density.enable = false
}
}
Technique 3: Disable Multi APK

27. productFlavors {
dev {
resConfigs('en', 'xhdpi')
...
}
}
Technique 4: Include Minimal Resources

28. buildTypes {
...
debug {
aaptOptions.cruncherEnabled = false
...
}
}
Technique 5: Disable PNG Crunching

29. Technique 6: Use Instant Run

30. buildTypes {
debug {
ext.alwaysUpdateBuildId = false
...
}
}
Technique 7: Disable Updating Build ID

31. android {
dependencies {
implementation 'com.android.support:appcompat-v7:+'
...
}
}
Technique 8: Don’t Use Dynamic Versions

32. org.gradle.jvmargs=-Xmx4096m -XX:MaxPermSize=1024m -XX:
+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
org.gradle.daemon=true
org.gradle.parallel=true
org.gradle.configureondemand=true
org.gradle.caching=true
android.enableBuildScriptClasspathCheck=false
Technique 9: Config gradle.properties

33. Available in Android Studio 3.3
Technique 10: Use R8 new code shrinker

34. BUILDING SPEED AFTER
~ 1 mins

35. CUMULATIVE IMPROVEMENT
3.02m 1m
3X Faster

36. ONE MORE THING…

37. What’s new in Android Studio 3.2
Android App Bundle

38. THANK YOU