Ty Smith discusses building lightweight yet powerful Fabric SDKs. The SDKs are easy to integrate, extensible to support different app types, minimize permissions and network usage, and reduce startup time and binary size. Fabric SDKs provide powerful functionality while remaining lightweight through techniques like using protocol buffers to reduce network traffic, setting lower thread priorities to decrease startup time, and minimizing included methods to reduce the Dalvik method count.

1. Building the Fabric SDKs
Ty Smith
October 28, 2014 @tsmith

2. Ty Smith
Sr. Android Engineer, Fabric
@tsmith

3. .io

8. Cannonball
Fabric Sample App
Open source for iOS & Android:
github.com/twitterdev

9. Powerful
Lightweight

10. Powerful

11. Ease of
Integration

12. Ease of Integration
Fabric.with(this, new Crashlytics());

13. Extensible

14. Extensible
Crashlytics.start(this);

15. Extensible
Crashlytics.start(this, 5);
Crashlytics.setListener(createCrashlyticsListener());
Crashlytics.setPinningInfo(createPinningInfoProvider())
Crashlytics.getInstance().setDebugMode(true);

16. Extensible
Crashlytics.setListener(createCrashlyticsListener());
Crashlytics.setPinningInfo(createPinningInfoProvider());
Crashlytics.getInstance().setDebugMode(true);
Crashlytics.start(this, 5);

17. Extensible
Crashlytics.start(this, delay, listener, pinningInfo,
debugMode);

18. Extensible
Crashlytics.start(this, 0, null, null, null, true);

19. Fluent Pattern
Crashlytics crashlytics = new Crashlytics.Builder()
.delay(1)
.listener(createCrashlyticsListener())
.pinningInfo(createPinningInfoProvider())
.build();
Fabric.with(this, crashlytics);

20. Fluent Pattern
Fabric.with(this, new Fabric.Builder(this)
.kits(new Crashlytics())
.debuggable(true)
.logger(new DefaultLogger(Log.VERBOSE))
.looper(getCustomLooper())
.executor(getCustomExecutorService())
.build());

21. Gracefully
Degrade

22. Gracefully Degrade
if (TextUtils.isEmpty(apiKey)
if (debuggable){
throw new IllegalArgumentException(
“apiKey is null!");
} else {
return null;
}
}

23. Minimizing
Permissions

24. Minimizing Permissions
<uses-permission android:name="android.permission.INTERNET"/>

25. Minimizing Permissions
Crashlytics.setUserEmail(“appuser@domain.com”);

26. Permissions:
Runtime Detection
protected boolean canCheckNetworkState() {
String permission =
“android.permission.ACCESS_NETWORK_STATE”;
int result =
context.checkCallingOrSelfPermission(permission);
return (result == PackageManager.PERMISSION_GRANTED);
}

27. Multiple
Application
Types

28. Multiple Application Types
package com.example;
import android.app.Service;
public class MyService
extends Service {
}

29. UI from Application Context
private WeakReference<Activity> currentActivity = new
WeakReference<Activity>();
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
private void registerLifecycleCallbacks() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
final Application app = ((Application)context);
app.registerActivityLifecycleCallbacks(
new ActivityLifecycleCallbacks() {
@Override
public void onActivityResumed(Activity activity) {
currentActivity.set(activity);
}
});
}
}

30. Powerful SDKs
Ease of Integration
Extensibility
Support all app types
Permission detection

31. Lightweight

32. Binary Size

33. Binary Size

34. 3rd Party
Library
Mindfulness

35. 3rd Party
Library Mindfulness
30
20
10
0

36. 3rd Party Library Mindfulness
PROTOBUF
KB
OURS
KB

37. Dalvik
Method
Count

38. Dalvik Method Count
>./gradlew assemble
…
Unable to execute dex: method ID not in [0,
0xffff]: 65536
Conversion to Dalvik format failed: Unable to
execute dex: method ID not in [0, 0xffff]: 65536

39. Dalvik Method Count
> git clone git@github.com:mihaip/dex-method-counts.git
> cd dex-method-counts
> ant jar
> ./dex-method-counts path/to/App.apk
Read in 65490 method IDs.
<root>: 65490
: 3
accessibilityservice: 6
bluetooth: 2
content: 248
pm: 22
res: 45
...
com: 53881
adjust: 283
sdk: 283

40. Minimize
Network
Usage

41. Network Usage
10X SMALLER
XML PROTOBUF
100X FASTER

42. Reduce
Startup
Time

43. Startup Time
Thread.start();
Executors.newSingleThreadExecutor();

44. Startup Time
class MyThreadFactory implements ThreadFactory {
@Override
public Thread newThread(Runnable runnable) {
final Thread thread = new Thread(runnable);
thread.setPriority(Process.THREAD_PRIORITY_BACKGROUND);
return thread;
}
}

45. Lightweight SDKs
Binary size
3rd party library mindfulness
Dalvik Method Count
Network usage
Startup time

46. Lightweight
Powerful

47. Thank You
@tsmith