Mobile Development - BTalk

Talks about general iOS development and some mobile stats on BTalk - a mobile messenger.

Transcript

1. Mobile Development Monday, January 21, 13
2. Agenda • Lifecycle of App • Mobile Design Principles • Responsive • Memory Management • Network • Maintainability • Other Stuffs Monday, January 21, 13
3. Lifecycle of an App Monday, January 21, 13
4. Monday, January 21, 13
5. Different states of App Active Background Suspended Inactive Not Running Monday, January 21, 13
6. Different states of App Active Background Suspended Inactive Not Running Monday, January 21, 13
7. Different states of App Active Background Suspended Inactive Not Running Free up memory Disconnect Reconnect Monday, January 21, 13
8. Mobile Design Principles • Performance • Responsiveness • Optimal memory usage • Network • Maintainability Monday, January 21, 13
9. Responsiveness • Never block the main thread • Always dispatch complex data handling to background threads • Utilize cache Monday, January 21, 13
10. Responsiveness • Image Processing User selects a picture Process Image Main Thread Update UI Background Monday, January 21, 13
11. Example: Image Processing BBImageLoop::Post(^{ processedImage = ImageProcessor.Process(image); BBUILoop::Post(^{ [self updateUI:processedImage]; }); }); User selects a picture Process Image BBUILoop Update UI BBImageLoop Monday, January 21, 13
12. Responsiveness • Queues • BBUILoop • BBSoundLoop • BBImageLoop • BBDLCoreData • BBDBLoop Monday, January 21, 13
13. Responsiveness • Queues/Operations are cancelable // Sending out Request tcp.requestNearbyBuddies(); handler = BBUILoop::DelayPost(^{ showTimeoutScreen(); }, 5000); ... ... // Response received BBUILoop::Cancel(handler); Monday, January 21, 13
14. • Queues • Use one queue per subsystem • Know your queues / threads • Can be cancelled Responsiveness Monday, January 21, 13
15. Memory Management User Experience Low Memory Usage Monday, January 21, 13
16. Memory Management User Experience Low Memory Usage App is Active Monday, January 21, 13
17. Memory Management User Experience Low Memory Usage App is in Background/Suspended Monday, January 21, 13
18. Memory Management • Active? • Use comfortably, but be practical • Inactive/Background? • Free up memory as much as possible • If not, Apple kills you in background Monday, January 21, 13
19. Anything lesser than that is a good gauge Memory Management Apps in Background Monday, January 21, 13
20. Optimal Memory Usage • Stay SAFE in background • Utilize system’s memory warning • Ensure no memory leaks Monday, January 21, 13
21. Use Instruments Monday, January 21, 13
22. Use Instruments Monday, January 21, 13
23. Network • Minimize network requests • Timeout is necessary • Always assume: Network is BAD Monday, January 21, 13
24. Network Monday, January 21, 13
25. Network • Bad network : Delays • Prevent sending out same requests before timeout • Cache responses Monday, January 21, 13
26. • Bad network : Disconnect • Queue critical requests • Fast / Safe Queue • Resend requests after reconnection • Requestid is essential Network Monday, January 21, 13
27. • Fast Queue • Safe Queue Network Client Client Server Server Monday, January 21, 13
28. • Fast Queue • Safe Queue Network Client Client Server Server Chats Daily Life Monday, January 21, 13
29. Maintainability • Modular Code • Easy to Read • Proper class/method names Monday, January 21, 13
30. Maintainability • BTalk is built on modular code Core Network FileSystem MediaEngine ... DailyLife ... Video Draw Monday, January 21, 13
31. Added by Daily Life Plugin Monday, January 21, 13
32. Added by Plugins Monday, January 21, 13
33. Maintainability Core Network FileSystem MediaEngine ... DailyLife ... Video Draw Plugin Manager register get Monday, January 21, 13
34. Some other stuffs la Monday, January 21, 13
35. Tracker • PivotalTracker • Schedule management tool cum bugs tracker • Manages schedule for you • Generate Weekly Report Monday, January 21, 13
36. PivotalTracker Monday, January 21, 13
37. PivotalTracker • Generated Weekly Report and Schedule Monday, January 21, 13
38. Insights on Mobile Stats Monday, January 21, 13
39. Insights on Mobile Stats • Uses Flurry SDK • ~20kB per session • Client stats collection is needed Monday, January 21, 13
40. Number of Sessions Monday, January 21, 13
41. Median Session Length Monday, January 21, 13
42. Session Length Monday, January 21, 13
43. User Paths Monday, January 21, 13
44. User Paths Monday, January 21, 13
45. Thank You 谢谢 Always write human readable code Monday, January 21, 13