Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Async Android
Search
Jamie McDonald
June 18, 2015
Programming
10
670
Async Android
NYC Android Developers Meetup, June 2015
Jamie McDonald
June 18, 2015
Tweet
Share
More Decks by Jamie McDonald
See All by Jamie McDonald
6 lessons learned scaling mobile
jdamcd
1
350
Android Engineering for Scale
jdamcd
13
2.2k
Other Decks in Programming
See All in Programming
🔨 小さなビルドシステムを作る
momeemt
4
670
テストコードはもう書かない:JetBrains AI Assistantに委ねる非同期処理のテスト自動設計・生成
makun
0
250
Navigating Dependency Injection with Metro
zacsweers
3
250
Performance for Conversion! 分散トレーシングでボトルネックを 特定せよ
inetand
0
140
プロポーザル駆動学習 / Proposal-Driven Learning
mackey0225
2
1.3k
ファインディ株式会社におけるMCP活用とサービス開発
starfish719
0
310
アセットのコンパイルについて
ojun9
0
120
意外と簡単!?フロントエンドでパスキー認証を実現する WebAuthn
teamlab
PRO
2
740
Zendeskのチケットを Amazon Bedrockで 解析した
ryokosuge
3
300
Go言語での実装を通して学ぶLLMファインチューニングの仕組み / fukuokago22-llm-peft
monochromegane
0
120
@Environment(\.keyPath)那么好我不允许你们不知道! / atEnvironment keyPath is so good and you should know it!
lovee
0
120
時間軸から考えるTerraformを使う理由と留意点
fufuhu
15
4.7k
Featured
See All Featured
How to Ace a Technical Interview
jacobian
279
23k
CoffeeScript is Beautiful & I Never Want to Write Plain JavaScript Again
sstephenson
162
15k
Testing 201, or: Great Expectations
jmmastey
45
7.7k
How to Create Impact in a Changing Tech Landscape [PerfNow 2023]
tammyeverts
53
2.9k
The Power of CSS Pseudo Elements
geoffreycrofte
77
6k
Build The Right Thing And Hit Your Dates
maggiecrowley
37
2.9k
Rails Girls Zürich Keynote
gr2m
95
14k
Unsuck your backbone
ammeep
671
58k
The Art of Programming - Codeland 2020
erikaheidi
56
13k
Build your cross-platform service in a week with App Engine
jlugia
231
18k
The Psychology of Web Performance [Beyond Tellerrand 2023]
tammyeverts
49
3k
How To Stay Up To Date on Web Technology
chriscoyier
790
250k
Transcript
None
Async Android Jamie McDonald
@Override public void onCreate() { super.onCreate(); Log.i(TAG, “Hi from the
main thread!”); } Main Thread title, date, 01 of 10
ANR title, date, 01 of 10
ANR title, date, 01 of 10 I/Choreographer﹕ Skipped 480 frames!
The application may be doing too much work on its main thread.
@UiThread public void updateUi(String title) { textView.setText(title); } @WorkerThread public
void showTitle() { textView.setText(SlowStuff.loadTitle()); } Tools title, date, 01 of 10
@UiThread public void updateUi(String title) { textView.setText(title); } @WorkerThread public
void showTitle() { textView.setText(SlowStuff.loadTitle()); } Tools title, date, 01 of 10
new Thread() { public void run() { final String result
= SlowStuff.blocking(); new Handler().post(new Runnable() { @Override public void run() { updateUi(result); } }); } }.start(); Thread title, date, 01 of 10
class LooperThread extends Thread { private Handler handler; public void
run() { Looper.prepare(); handler = new Handler() { public void handleMessage(Message msg) { // Process messages here } }; Looper.loop(); } } Looper title, date, 01 of 10
IntentService title, date, 01 of 10 public class BackgroundService extends
IntentService { public BackgroundService() { super("BackgroundWork"); } @Override protected void onHandleIntent(Intent intent) { SlowStuff.blocking(); } } startService(new Intent(this, BackgroundService.class));
new AsyncTask<Void, Void, String>() { @Override protected String doInBackground(Void... params)
{ return SlowStuff.blocking(); } @Override protected void onPostExecute(String s) { updateUi(s); } }.execute(); AsyncTask title, date, 01 of 10
title, date, 01 of 10 “Painless threading” - The year
2009
new AsyncTask<Void, Void, Result>() { [...] @Override protected void onPostExecute(Result
result) { if (result.isSuccess()) { doNextAsyncStep(result.getValue()); } else { // ??? } } }.execute(); Callback Hell title, date, 01 of 10
Execution Order title, date, 01 of 10 SERIAL SERIAL THREAD
POOL
class DataLoader extends AsyncTaskLoader<String> { public BackgroundLoader(Context context) { super(context);
} @Override protected void onStartLoading() { forceLoad(); } @Override public String loadInBackground() { return SlowStuff.blocking(); } } Loader title, date, 01 of 10
getLoaderManager().initLoader(LOADER_ID, null, new LoaderManager.LoaderCallbacks<String>() { @Override public Loader<String> onCreateLoader(int id,
Bundle args) { return new DataLoader(MainActivity.this); } @Override public void onLoadFinished(Loader<String> loader, String text) { updateUi(text); } @Override public void onLoaderReset(Loader<String> loader) { loader.reset(); } }); Loader title, date, 01 of 10
Enter RxJava!
RxJava title, date, 01 of 10 “RxJava tries to be
very lightweight. [...] focused on just the Observable abstraction and related higher-order functions”
Observer Pattern title, date, 01 of 10
Streams title, date, 01 of 10
public Observable<String> observable() { return Observable.create((subscriber) -> { subscriber.onNext(blocking()); subscriber.onCompleted();
}); } Observable title, date, 01 of 10
class MySubscriber extends DefaultSubscriber<String> { @Override public void onNext(String text)
{ updateUi(text); } @Override public void onError(Throwable e) { displayError(e); } } Subscriber title, date, 01 of 10
SlowStuff.observable() .subscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) .subscribe(new MySubscriber()); Schedulers title, date, 01 of
10
title, date, 01 of 10 Thread IntentService AsyncTask Loader RxJava
Main thread callbacks Configuration changes Error handling Composability Flexible scheduling
Operators title, date, 01 of 10 flatMap map filter doOnNext
onErrorResumeNext distinct cache zip retry ...
FlatMap title, date, 01 of 10
trackOps.loadWaveformUrl(urn) .flatMap(url -> imageOps.renderWaveform(url)) .onErrorResumeNext(imageOps.defaultWaveform()) [...] .subscribe(new WaveformSubscriber()); FlatMap title,
date, 01 of 10
OnErrorResumeNext title, date, 01 of 10
public final class EventQueue { static final Queue<StateTransition> PLAYBACK_STATE; static
final Queue<ProgressEvent> PLAYBACK_PROGRESS; static final Queue<PlayableEvent> PLAYABLE_CHANGED; [...] } Event Bus title, date, 01 of 10
None
title, date, 01 of 10
Subtitle title, date, 01 of 10 eventBus.queue(EventQueue.PLAYABLE_CHANGE) .filter(PlayableEvent.IS_TRACK_FILTER) .doOnNext(updateLikeCount) .observeOn(AndroidSchedulers.mainThread())
Only listen to interesting events
Subtitle Respond to state without storing it title, date, 01
of 10 Observable.combineLatest( eventBus.queue(EventQueue.PLAY_QUEUE_TRACK), eventBus.queue(EventQueue.PLAYER_UI), combineStates) .doOnNext(setTrackHasBeenSeen)
Downsides title, date, 01 of 10 Debugging Testing long call
chains Learning curve Boilerplate Config changes Backpressure Where & when to use it?
*£#%@£$?? title, date, 01 of 10
More title, date, 01 of 10 RxAndroid Not RxAndroid Retrofit
Retrolambda
soundcloud.com/jobs Thank you, NYC!