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Android Performance Tips & Tricks
Sergii ZhukAndroid Developer at DAXX BV
Kyiv, FrameworksDays Android Saturday, 2015-06-06
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Agenda
• Effective Java in Android
• Layouts and UI
• Proper Use of Resources
• Dev Tools and Measuring Performance
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Effective Java in Android
• Avoid using Floating-Point
• Prefer primitives and primitive-backed data structures (ArrayMap, SparseArray)
• Two parallel (int) arrays are better than array (int,int)
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Effective Java in Android
• System.arraycopy() is about 9x faster than a hand-coded loop
• Make your method static: invocations will be about 15%-20% faster
• Do not use EnumsWAT?? @IntDef annotation
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Supplying Scaled Drawables
• Why not to supply a single xhdpi image as blurred background for the screen?
• Rendering performance will decrease because device should scale your image during app execution
• Such operation requires extra memory for Bitmap native processing, potential source of OutOfMemoryError
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Make Your Layouts Flat
• Inflating layout is a top-down traversal of the view tree
• Hierarchy Viewer (Android SDK) allows to analyze layout while your application is running
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“Heavy” ViewGroups
• RelativeLayout requires two measurement passes to ensure that it has handled all of the layout relationships
• The same is valid for LinearLayout with layout weights
• If one of the children of ViewGroups shown above is again RelativeLayout or LinearLayout with weights – four measurements passes will be required for sub-hierarchy
• GridLayout could be good solution in some cases (API 14+)
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GridLayout example
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Splash Screen Effect
• Show a blank window constructed with the application theme, including specified background drawable while application is starting
• Behavior is provided by OS
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Splash Screen Effect
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ViewStub
• A lightweight view with no dimension and doesn’t draw anything or participate in the layout
• Use ViewStub as a “lazy include” for sub-hierarchies that can be optionally inflated later.
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Develop for the Low End
• Devices distribution in the world
• Most of users could have lower-end devices than yours
• Use ActivityManager.isLowRamDevice() to detect if device in the class of a 512MB RAM and/or about a 800x480 screen [API 19+]
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Develop for the Low End
* More details at my Stackoverflow.com question
Nexus 4 (Genymotion emu) and other devices
Lenovo P780 with Android 4.2.1
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Remove unused resources
• Lint (Android SDK): will highlight these resources
• Android-resource-remover (consumes Lint output)
• Gradle: buildTypes {release {
minifyEnabled true shrinkResources true
}}
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Multiple APKs on Play Store
• Different APKs for your app that are each targeted to different device configurations
• Have same app listing on Google Play and must share the same package name and be signed with the same release key
• Recommended to use multiple APKs only when your APK is too large (> 50MB)
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Gradle Plugin: APK splits
android { ... splits { density {
enable truereset()exclude "ldpi", "tvdpi", "xxxhdpi"
}}
WARN: you will need to set different version code for each APK file
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Developer Options On Your Device
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Developer Options On Your Device
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Avoid Requesting a Large Heap
• Requesting a larger heap may be necessary in some rare situations like media content
• android:largeHeap=“true” result: less memory to be available for other apps, necessitating them being killed and restarted
• android:largeHeap seems to be not enough documented
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Memory Leaks
• If a chain of references holds an object in memory after the end of its expected lifetime
• Old approach: Dump Fix header MAT Find leak
• New approach: LeakCanary will notify you
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LeakCanary dependencies { debugCompile 'com.squareup.leakcanary:leakcanary-android:1.3.1' releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.3.1' }
public class ExampleApplication extends Application {
@Override public void onCreate() { super.onCreate(); LeakCanary.install(this); }}
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LeakCanary
* Sometimes you still need MAT
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In-app performance check
• StrictMode
• Google’s profiling tools: Traceview & dmtracedump
• Hugo by Jake Wharton
• Tools like NewRelic to show bottlenecks in response time
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References• http://developer.android.com/training/articles/perf-tips.html• Chet Haase at Medium: Developing for Android (parts 1-5)• Memory leaks in Android (in Russian)• Android Performance Case Study by Romain Guy• Is Android layout really exponentially hard? SO discussion • Pro Android Apps Performance Optimization by Herv Guihot• Eric Lafortune talk on MCE2015 Conference• Cyril Mottier blog• Taylor Ling blog• Romain Guy blog• Android Performance Patterns (YouTube and G+)• DOU.ua Android Digest
