Part Ⅰ．Getting Started 3
1．Performance in Mobile Apps 3
Defining Performance 4
Performance Metrics 4
Memory 4
Power Consumption 4
Initialization Time 5
Execution Speed 5
Responsiveness 6
Local Storage 6
Interoperability 7
Network Condition 8
Bandwidth 9
Data Refresh 9
Multiuser Support 9
Single Sign-on 11
Security 11
Crashes 11
App Profiling 12
Sampling 12
Instrumentation 12
Measurement 12
Project and Code Setup 13
Crash Reporting Setup 14
Instrumenting Your App 15
Logging 20
Summary 23
Part Ⅱ．Core Optimizations 27
2．Memory Management 27
Memory Consumption 28
Stack Size 28
Heap Size 29
Memory Management Model 32
Autoreleasing Objects 34
Autorelease Pool Blocks 35
Automatic Reference Counting 39
Rules of ARC 41
Reference Types 42
Variable Qualifiers 43
Property Qualifiers 44
Getting Your Hands Dirty 45
Photo Model 45
Storyboard Update 46
Method Implementations 47
Output Analysis 49
Zombies 50
Rules of Memory Management 51
Retain Cycles 52
Rules to Avoid Retain Cycles 53
Common Scenarios for Retain Cycles 54
Observers 67
Returning Errors 70
Weak Type：id 71
Solution to the Problem 72
Object Longevity and Leaks 74
Singletons 74
Finding Mystery Retains 77
Best Practices 78
Memory Usage in Production 79
Summary 80
3．Energy 81
CPU 81
Network 83
Location Manager and GPS 87
Optimal Initialization 89
Turn Off Inessential Features 90
Use Network Only If Essential 92
Background Location Services 92
NSTimers,NSThreads,and Location Services 93
Restart After App Kill 93
Screen 94
Animation 94
Video Play 94
Multiple Screens 94
Other Hardware 99
Battery Level and State-Aware Code 100
Profiling for Energy Use 102
Best Practices 103
Summary 106
4．Concurrent Programming 107
Threads 107
The Cost of Threads 108
Kernel Data Structures 108
Stack Size 108
Creation Time 109
GCD 109
Operations and Queues 110
Thread-Safe Code 112
Atomic Properties 112
Synchronized Blocks 113
Locks 115
Use Reader-Writer Locks for Concurrent Reads and Writes 121
Use Immutable Entities 123
Have a Central State Updater Service 128
State Observers and Notifications 134
Prefer Async over Sync 139
Summary 141
Part Ⅲ．iOS Performance 145
5．Application Lifecycle 145
App Delegate 145
Application Launch 147
First Launch 150
Cold Start 158
Warm Launch 166
Launch After Upgrade 169
Push Notifications 169
Remote Notifications 169
Local Notifications 173
Background Fetch 174
Summary 177
6．User Interface 179
View Controller 181
View Load 183
View Hierarchy 184
View Visibility 187
View 189
UILabel 191
UIButton 192
UIImageView 194
UITableView 195
UIWebView 199
Custom Views 203
Auto Layout 210
Size Classes 212
New Interaction Features in iOS 8 217
Interactive Notifications 217
App Extensions 219
Summary 222
7．Network 223
Metrics and Measurement 223
DNS Lookup Time 224
SSL Handshake Time 226
Network Type 227
Latency 234
Networking API 237
App Deployment 238
Servers 238
Request 239
Data Format 240
Tools 241
Network Link Conditioner 241
AT＆T Application Resource Optimizer 243
Charles 245
Summary 248
8．Data Sharing 251
Deep Linking 252
Pasteboards 258
Sharing Content 261
Document Interaction 262
Activities 271
iOS 8 Extensions 274
Configuration for Action and Share Extensions 276
Action Extensions 277
Share Extensions 278
Document Provider Extension 282
App Groups 287
Summary 289
9．Security 291
App Access 292
Anonymous Access 292
Authenticated Access 294
Network Security 299
Use HTTPS 299
Use Certificate Pinning 300
Local Storage 305
Data Sharing 312
Security and App Performance 312
Checklist 313
Summary 315
Part Ⅳ．Beyond Code 315
10．Testingand Release 319
Test Types 319
Definitions 320
Unit Testing 321
Setup 321
Writing Unit Tests 323
Code Coverage 325
Asynchronous Operations 330
Xcode 6 Bonus：Performance Unit Tests 331
Dependency Mocking 333
Other Frameworks 337
Functional Testing 338
Setup 339
Writing Functional Tests 341
Project Structure 344
Dependency Isolation 345
Testing and Component Design 347
Continuous Integration and Automation 349
Best Practices 351
Performance Testing 352
Summary 355
11．Tools 357
Accessibility Inspector 358
Xcode Accessibility Inspector 359
iOS Accessibility Inspector 360
Instruments 363
Using Instruments 364
Activity Monitor 367
Allocations 369
Leaks 372
Network 374
Time Profiler 374
Xcode View Debugger 375
PonyDebugger 377
Charles 382
Summary 388
12．Instrumentation and Analytics 389
Vocabulary 390
Instrumentation 391
Planning 392
Implementation 395
Deployment 398
Analytics 398
Real User Monitoring 399
Analytics Versus Real User Monitoring 399
Using RUM 399
Summary 400
Part Ⅴ．iOS9 401
13．iOS 9 403
Application Lifecycle 403
Universal Links 404
Search 407
Search Best Practices 412
User Interface 414
UIKit Framework 414
Safari Services Framework 418
Extensions 421
Content Blocker Extension 422
Spotlight Index Extension 426
App Thinning 426
Slicing 427
On Demand Resources 427
Bitcode 431
Summary 432
Index 433