Deep Performance Tuning (深度性能优化)

Instructions

• 仅在有量测数据或明确瓶颈时使用
• 依照下方章节顺序套用
• 一次只施作一种优化并验证效果
• 完成后对照 Quick Checklist

When to Use

• Scenario D：性能问题排查
• Scenario E：发布前性能验证

Example Prompts

• “请参考 App Startup Optimization，创建 Macrobenchmark 测量”
• “用 Memory Analysis 章节，规划内存分析流程”
• “请依照 R8/Proguard Optimization，检查规则是否完整”

Workflow

1. 先创建量测基准（Startup/Memory/UI）
2. 再逐一套用对应优化手段
3. 最后用 Quick Checklist 验收

Practical Notes (2026)

• Baseline Profile + Macrobenchmark 作为默认流程
• 每次只做一项优化并量测差异
• 性能门槛要进 CI Gate

Minimal Template

目标: 
量测基准: 
优化范围: 
回归指标: 
验收: Quick Checklist

App Startup Optimization

Macrobenchmark 测量

@LargeTest
@RunWith(AndroidJUnit4::class)
class StartupBenchmark {
    
    @get:Rule
    val benchmarkRule = MacrobenchmarkRule()
    
    @Test
    fun startupCompilationNone() = startup(CompilationMode.None())
    
    @Test
    fun startupCompilationPartial() = startup(CompilationMode.Partial())
    
    private fun startup(compilationMode: CompilationMode) {
        benchmarkRule.measureRepeated(
            packageName = "com.example.app",
            metrics = listOf(StartupTimingMetric()),
            compilationMode = compilationMode,
            iterations = 5,
            startupMode = StartupMode.COLD
        ) {
            pressHome()
            startActivityAndWait()
        }
    }
}

Baseline Profiles

// 生成 Baseline Profile
@RunWith(AndroidJUnit4::class)
class BaselineProfileGenerator {
    
    @get:Rule
    val rule = BaselineProfileRule()
    
    @Test
    fun generate() {
        rule.collect("com.example.app") {
            pressHome()
            startActivityAndWait()
            
            // 关键路径
            device.findObject(By.text("Login")).click()
            device.wait(Until.hasObject(By.text("Home")), 5000)
        }
    }
}

Application onCreate 优化

class MyApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        
        // ❌ 同步初始化 (Block UI)
        // Firebase.initialize(this)
        // Timber.plant(DebugTree())
        
        // ✅ 延迟初始化
        AppInitializer.getInstance(this)
            .initializeComponent(FirebaseInitializer::class.java)
        
        // ✅ 背景初始化
        ProcessLifecycleOwner.get().lifecycle.addObserver(
            object : DefaultLifecycleObserver {
                override fun onCreate(owner: LifecycleOwner) {
                    lifecycleScope.launch(Dispatchers.Default) {
                        // 非关键初始化
                    }
                }
            }
        )
    }
}

Memory Analysis

Heap Dump 分析

# 取得 Heap Dump
adb shell am dumpheap com.example.app /data/local/tmp/heap.hprof
adb pull /data/local/tmp/heap.hprof

# 使用 Android Studio Profiler 分析
# 或使用 MAT (Memory Analyzer Tool)

LeakCanary 设置

// build.gradle.kts
debugImplementation("com.squareup.leakcanary:leakcanary-android:2.12")

// 自定义报告
class MyApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        LeakCanary.config = LeakCanary.config.copy(
            retainedVisibleThreshold = 3,
            objectInspectors = AndroidObjectInspectors.appDefaults
        )
    }
}

Bitmap 内存管理

// 使用 Coil 自动管理
AsyncImage(
    model = ImageRequest.Builder(LocalContext.current)
        .data(imageUrl)
        .size(Size.ORIGINAL)  // 根据需求调整
        .memoryCachePolicy(CachePolicy.ENABLED)
        .build(),
    contentDescription = null
)

R8/Proguard Optimization

自定义规则

# 保留 Serializable
-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    !static !transient <fields>;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
}

# 保留 Retrofit Interface
-keep,allowobfuscation interface * {
    @retrofit2.http.* <methods>;
}

# 保留 Compose stability
-keep class * {
    @androidx.compose.runtime.Stable *;
    @androidx.compose.runtime.Immutable *;
}

APK Size 分析

# 使用 bundletool
bundletool build-apks --bundle=app.aab --output=app.apks
bundletool get-size total --apks=app.apks

# Android Studio: Build > Analyze APK

UI Performance

JankStats

class MainActivity : ComponentActivity() {
    private lateinit var jankStats: JankStats
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        
        jankStats = JankStats.createAndTrack(window) { frameData ->
            if (frameData.isJank) {
                Log.w("Jank", "Frame took ${frameData.frameDurationUiNanos / 1_000_000}ms")
            }
        }
    }
}

Compose Recomposition Tracking

// 打开 Composition Tracking
@Composable
fun DebugComposable() {
    SideEffect {
        Log.d("Recomposition", "DebugComposable recomposed")
    }
}

// 使用 Layout Inspector 检查 recomposition count

Quick Checklist

• Startup: Baseline Profiles 生成
• Startup: Application onCreate 延迟初始化
• Memory: LeakCanary 无泄漏
• APK: R8 规则完善
• UI: JankStats 无严重掉帧